diff options
Diffstat (limited to 'fs/btrfs/inode.c')
| -rw-r--r-- | fs/btrfs/inode.c | 9907 |
1 files changed, 9907 insertions, 0 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c new file mode 100644 index 000000000..8bb013672 --- /dev/null +++ b/fs/btrfs/inode.c @@ -0,0 +1,9907 @@ +/* + * Copyright (C) 2007 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include <linux/kernel.h> +#include <linux/bio.h> +#include <linux/buffer_head.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/pagemap.h> +#include <linux/highmem.h> +#include <linux/time.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/backing-dev.h> +#include <linux/mpage.h> +#include <linux/swap.h> +#include <linux/writeback.h> +#include <linux/statfs.h> +#include <linux/compat.h> +#include <linux/bit_spinlock.h> +#include <linux/xattr.h> +#include <linux/posix_acl.h> +#include <linux/falloc.h> +#include <linux/slab.h> +#include <linux/ratelimit.h> +#include <linux/mount.h> +#include <linux/btrfs.h> +#include <linux/blkdev.h> +#include <linux/posix_acl_xattr.h> +#include <linux/uio.h> +#include "ctree.h" +#include "disk-io.h" +#include "transaction.h" +#include "btrfs_inode.h" +#include "print-tree.h" +#include "ordered-data.h" +#include "xattr.h" +#include "tree-log.h" +#include "volumes.h" +#include "compression.h" +#include "locking.h" +#include "free-space-cache.h" +#include "inode-map.h" +#include "backref.h" +#include "hash.h" +#include "props.h" +#include "qgroup.h" + +struct btrfs_iget_args { + struct btrfs_key *location; + struct btrfs_root *root; +}; + +static const struct inode_operations btrfs_dir_inode_operations; +static const struct inode_operations btrfs_symlink_inode_operations; +static const struct inode_operations btrfs_dir_ro_inode_operations; +static const struct inode_operations btrfs_special_inode_operations; +static const struct inode_operations btrfs_file_inode_operations; +static const struct address_space_operations btrfs_aops; +static const struct address_space_operations btrfs_symlink_aops; +static const struct file_operations btrfs_dir_file_operations; +static struct extent_io_ops btrfs_extent_io_ops; + +static struct kmem_cache *btrfs_inode_cachep; +static struct kmem_cache *btrfs_delalloc_work_cachep; +struct kmem_cache *btrfs_trans_handle_cachep; +struct kmem_cache *btrfs_transaction_cachep; +struct kmem_cache *btrfs_path_cachep; +struct kmem_cache *btrfs_free_space_cachep; + +#define S_SHIFT 12 +static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = { + [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE, + [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR, + [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV, + [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV, + [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO, + [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK, + [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK, +}; + +static int btrfs_setsize(struct inode *inode, struct iattr *attr); +static int btrfs_truncate(struct inode *inode); +static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent); +static noinline int cow_file_range(struct inode *inode, + struct page *locked_page, + u64 start, u64 end, int *page_started, + unsigned long *nr_written, int unlock); +static struct extent_map *create_pinned_em(struct inode *inode, u64 start, + u64 len, u64 orig_start, + u64 block_start, u64 block_len, + u64 orig_block_len, u64 ram_bytes, + int type); + +static int btrfs_dirty_inode(struct inode *inode); + +#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS +void btrfs_test_inode_set_ops(struct inode *inode) +{ + BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; +} +#endif + +static int btrfs_init_inode_security(struct btrfs_trans_handle *trans, + struct inode *inode, struct inode *dir, + const struct qstr *qstr) +{ + int err; + + err = btrfs_init_acl(trans, inode, dir); + if (!err) + err = btrfs_xattr_security_init(trans, inode, dir, qstr); + return err; +} + +/* + * this does all the hard work for inserting an inline extent into + * the btree. The caller should have done a btrfs_drop_extents so that + * no overlapping inline items exist in the btree + */ +static int insert_inline_extent(struct btrfs_trans_handle *trans, + struct btrfs_path *path, int extent_inserted, + struct btrfs_root *root, struct inode *inode, + u64 start, size_t size, size_t compressed_size, + int compress_type, + struct page **compressed_pages) +{ + struct extent_buffer *leaf; + struct page *page = NULL; + char *kaddr; + unsigned long ptr; + struct btrfs_file_extent_item *ei; + int err = 0; + int ret; + size_t cur_size = size; + unsigned long offset; + + if (compressed_size && compressed_pages) + cur_size = compressed_size; + + inode_add_bytes(inode, size); + + if (!extent_inserted) { + struct btrfs_key key; + size_t datasize; + + key.objectid = btrfs_ino(inode); + key.offset = start; + key.type = BTRFS_EXTENT_DATA_KEY; + + datasize = btrfs_file_extent_calc_inline_size(cur_size); + path->leave_spinning = 1; + ret = btrfs_insert_empty_item(trans, root, path, &key, + datasize); + if (ret) { + err = ret; + goto fail; + } + } + leaf = path->nodes[0]; + ei = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + btrfs_set_file_extent_generation(leaf, ei, trans->transid); + btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); + btrfs_set_file_extent_encryption(leaf, ei, 0); + btrfs_set_file_extent_other_encoding(leaf, ei, 0); + btrfs_set_file_extent_ram_bytes(leaf, ei, size); + ptr = btrfs_file_extent_inline_start(ei); + + if (compress_type != BTRFS_COMPRESS_NONE) { + struct page *cpage; + int i = 0; + while (compressed_size > 0) { + cpage = compressed_pages[i]; + cur_size = min_t(unsigned long, compressed_size, + PAGE_CACHE_SIZE); + + kaddr = kmap_atomic(cpage); + write_extent_buffer(leaf, kaddr, ptr, cur_size); + kunmap_atomic(kaddr); + + i++; + ptr += cur_size; + compressed_size -= cur_size; + } + btrfs_set_file_extent_compression(leaf, ei, + compress_type); + } else { + page = find_get_page(inode->i_mapping, + start >> PAGE_CACHE_SHIFT); + btrfs_set_file_extent_compression(leaf, ei, 0); + kaddr = kmap_atomic(page); + offset = start & (PAGE_CACHE_SIZE - 1); + write_extent_buffer(leaf, kaddr + offset, ptr, size); + kunmap_atomic(kaddr); + page_cache_release(page); + } + btrfs_mark_buffer_dirty(leaf); + btrfs_release_path(path); + + /* + * we're an inline extent, so nobody can + * extend the file past i_size without locking + * a page we already have locked. + * + * We must do any isize and inode updates + * before we unlock the pages. Otherwise we + * could end up racing with unlink. + */ + BTRFS_I(inode)->disk_i_size = inode->i_size; + ret = btrfs_update_inode(trans, root, inode); + + return ret; +fail: + return err; +} + + +/* + * conditionally insert an inline extent into the file. This + * does the checks required to make sure the data is small enough + * to fit as an inline extent. + */ +static noinline int cow_file_range_inline(struct btrfs_root *root, + struct inode *inode, u64 start, + u64 end, size_t compressed_size, + int compress_type, + struct page **compressed_pages) +{ + struct btrfs_trans_handle *trans; + u64 isize = i_size_read(inode); + u64 actual_end = min(end + 1, isize); + u64 inline_len = actual_end - start; + u64 aligned_end = ALIGN(end, root->sectorsize); + u64 data_len = inline_len; + int ret; + struct btrfs_path *path; + int extent_inserted = 0; + u32 extent_item_size; + + if (compressed_size) + data_len = compressed_size; + + if (start > 0 || + actual_end > PAGE_CACHE_SIZE || + data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) || + (!compressed_size && + (actual_end & (root->sectorsize - 1)) == 0) || + end + 1 < isize || + data_len > root->fs_info->max_inline) { + return 1; + } + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + trans->block_rsv = &root->fs_info->delalloc_block_rsv; + + if (compressed_size && compressed_pages) + extent_item_size = btrfs_file_extent_calc_inline_size( + compressed_size); + else + extent_item_size = btrfs_file_extent_calc_inline_size( + inline_len); + + ret = __btrfs_drop_extents(trans, root, inode, path, + start, aligned_end, NULL, + 1, 1, extent_item_size, &extent_inserted); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out; + } + + if (isize > actual_end) + inline_len = min_t(u64, isize, actual_end); + ret = insert_inline_extent(trans, path, extent_inserted, + root, inode, start, + inline_len, compressed_size, + compress_type, compressed_pages); + if (ret && ret != -ENOSPC) { + btrfs_abort_transaction(trans, root, ret); + goto out; + } else if (ret == -ENOSPC) { + ret = 1; + goto out; + } + + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); + btrfs_delalloc_release_metadata(inode, end + 1 - start); + btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0); +out: + btrfs_free_path(path); + btrfs_end_transaction(trans, root); + return ret; +} + +struct async_extent { + u64 start; + u64 ram_size; + u64 compressed_size; + struct page **pages; + unsigned long nr_pages; + int compress_type; + struct list_head list; +}; + +struct async_cow { + struct inode *inode; + struct btrfs_root *root; + struct page *locked_page; + u64 start; + u64 end; + struct list_head extents; + struct btrfs_work work; +}; + +static noinline int add_async_extent(struct async_cow *cow, + u64 start, u64 ram_size, + u64 compressed_size, + struct page **pages, + unsigned long nr_pages, + int compress_type) +{ + struct async_extent *async_extent; + + async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); + BUG_ON(!async_extent); /* -ENOMEM */ + async_extent->start = start; + async_extent->ram_size = ram_size; + async_extent->compressed_size = compressed_size; + async_extent->pages = pages; + async_extent->nr_pages = nr_pages; + async_extent->compress_type = compress_type; + list_add_tail(&async_extent->list, &cow->extents); + return 0; +} + +static inline int inode_need_compress(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + + /* force compress */ + if (btrfs_test_opt(root, FORCE_COMPRESS)) + return 1; + /* bad compression ratios */ + if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) + return 0; + if (btrfs_test_opt(root, COMPRESS) || + BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS || + BTRFS_I(inode)->force_compress) + return 1; + return 0; +} + +/* + * we create compressed extents in two phases. The first + * phase compresses a range of pages that have already been + * locked (both pages and state bits are locked). + * + * This is done inside an ordered work queue, and the compression + * is spread across many cpus. The actual IO submission is step + * two, and the ordered work queue takes care of making sure that + * happens in the same order things were put onto the queue by + * writepages and friends. + * + * If this code finds it can't get good compression, it puts an + * entry onto the work queue to write the uncompressed bytes. This + * makes sure that both compressed inodes and uncompressed inodes + * are written in the same order that the flusher thread sent them + * down. + */ +static noinline void compress_file_range(struct inode *inode, + struct page *locked_page, + u64 start, u64 end, + struct async_cow *async_cow, + int *num_added) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + u64 num_bytes; + u64 blocksize = root->sectorsize; + u64 actual_end; + u64 isize = i_size_read(inode); + int ret = 0; + struct page **pages = NULL; + unsigned long nr_pages; + unsigned long nr_pages_ret = 0; + unsigned long total_compressed = 0; + unsigned long total_in = 0; + unsigned long max_compressed = 128 * 1024; + unsigned long max_uncompressed = 128 * 1024; + int i; + int will_compress; + int compress_type = root->fs_info->compress_type; + int redirty = 0; + + /* if this is a small write inside eof, kick off a defrag */ + if ((end - start + 1) < 16 * 1024 && + (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) + btrfs_add_inode_defrag(NULL, inode); + + actual_end = min_t(u64, isize, end + 1); +again: + will_compress = 0; + nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1; + nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE); + + /* + * we don't want to send crud past the end of i_size through + * compression, that's just a waste of CPU time. So, if the + * end of the file is before the start of our current + * requested range of bytes, we bail out to the uncompressed + * cleanup code that can deal with all of this. + * + * It isn't really the fastest way to fix things, but this is a + * very uncommon corner. + */ + if (actual_end <= start) + goto cleanup_and_bail_uncompressed; + + total_compressed = actual_end - start; + + /* + * skip compression for a small file range(<=blocksize) that + * isn't an inline extent, since it dosen't save disk space at all. + */ + if (total_compressed <= blocksize && + (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) + goto cleanup_and_bail_uncompressed; + + /* we want to make sure that amount of ram required to uncompress + * an extent is reasonable, so we limit the total size in ram + * of a compressed extent to 128k. This is a crucial number + * because it also controls how easily we can spread reads across + * cpus for decompression. + * + * We also want to make sure the amount of IO required to do + * a random read is reasonably small, so we limit the size of + * a compressed extent to 128k. + */ + total_compressed = min(total_compressed, max_uncompressed); + num_bytes = ALIGN(end - start + 1, blocksize); + num_bytes = max(blocksize, num_bytes); + total_in = 0; + ret = 0; + + /* + * we do compression for mount -o compress and when the + * inode has not been flagged as nocompress. This flag can + * change at any time if we discover bad compression ratios. + */ + if (inode_need_compress(inode)) { + WARN_ON(pages); + pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); + if (!pages) { + /* just bail out to the uncompressed code */ + goto cont; + } + + if (BTRFS_I(inode)->force_compress) + compress_type = BTRFS_I(inode)->force_compress; + + /* + * we need to call clear_page_dirty_for_io on each + * page in the range. Otherwise applications with the file + * mmap'd can wander in and change the page contents while + * we are compressing them. + * + * If the compression fails for any reason, we set the pages + * dirty again later on. + */ + extent_range_clear_dirty_for_io(inode, start, end); + redirty = 1; + ret = btrfs_compress_pages(compress_type, + inode->i_mapping, start, + total_compressed, pages, + nr_pages, &nr_pages_ret, + &total_in, + &total_compressed, + max_compressed); + + if (!ret) { + unsigned long offset = total_compressed & + (PAGE_CACHE_SIZE - 1); + struct page *page = pages[nr_pages_ret - 1]; + char *kaddr; + + /* zero the tail end of the last page, we might be + * sending it down to disk + */ + if (offset) { + kaddr = kmap_atomic(page); + memset(kaddr + offset, 0, + PAGE_CACHE_SIZE - offset); + kunmap_atomic(kaddr); + } + will_compress = 1; + } + } +cont: + if (start == 0) { + /* lets try to make an inline extent */ + if (ret || total_in < (actual_end - start)) { + /* we didn't compress the entire range, try + * to make an uncompressed inline extent. + */ + ret = cow_file_range_inline(root, inode, start, end, + 0, 0, NULL); + } else { + /* try making a compressed inline extent */ + ret = cow_file_range_inline(root, inode, start, end, + total_compressed, + compress_type, pages); + } + if (ret <= 0) { + unsigned long clear_flags = EXTENT_DELALLOC | + EXTENT_DEFRAG; + unsigned long page_error_op; + + clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0; + page_error_op = ret < 0 ? PAGE_SET_ERROR : 0; + + /* + * inline extent creation worked or returned error, + * we don't need to create any more async work items. + * Unlock and free up our temp pages. + */ + extent_clear_unlock_delalloc(inode, start, end, NULL, + clear_flags, PAGE_UNLOCK | + PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK | + page_error_op | + PAGE_END_WRITEBACK); + goto free_pages_out; + } + } + + if (will_compress) { + /* + * we aren't doing an inline extent round the compressed size + * up to a block size boundary so the allocator does sane + * things + */ + total_compressed = ALIGN(total_compressed, blocksize); + + /* + * one last check to make sure the compression is really a + * win, compare the page count read with the blocks on disk + */ + total_in = ALIGN(total_in, PAGE_CACHE_SIZE); + if (total_compressed >= total_in) { + will_compress = 0; + } else { + num_bytes = total_in; + } + } + if (!will_compress && pages) { + /* + * the compression code ran but failed to make things smaller, + * free any pages it allocated and our page pointer array + */ + for (i = 0; i < nr_pages_ret; i++) { + WARN_ON(pages[i]->mapping); + page_cache_release(pages[i]); + } + kfree(pages); + pages = NULL; + total_compressed = 0; + nr_pages_ret = 0; + + /* flag the file so we don't compress in the future */ + if (!btrfs_test_opt(root, FORCE_COMPRESS) && + !(BTRFS_I(inode)->force_compress)) { + BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; + } + } + if (will_compress) { + *num_added += 1; + + /* the async work queues will take care of doing actual + * allocation on disk for these compressed pages, + * and will submit them to the elevator. + */ + add_async_extent(async_cow, start, num_bytes, + total_compressed, pages, nr_pages_ret, + compress_type); + + if (start + num_bytes < end) { + start += num_bytes; + pages = NULL; + cond_resched(); + goto again; + } + } else { +cleanup_and_bail_uncompressed: + /* + * No compression, but we still need to write the pages in + * the file we've been given so far. redirty the locked + * page if it corresponds to our extent and set things up + * for the async work queue to run cow_file_range to do + * the normal delalloc dance + */ + if (page_offset(locked_page) >= start && + page_offset(locked_page) <= end) { + __set_page_dirty_nobuffers(locked_page); + /* unlocked later on in the async handlers */ + } + if (redirty) + extent_range_redirty_for_io(inode, start, end); + add_async_extent(async_cow, start, end - start + 1, + 0, NULL, 0, BTRFS_COMPRESS_NONE); + *num_added += 1; + } + + return; + +free_pages_out: + for (i = 0; i < nr_pages_ret; i++) { + WARN_ON(pages[i]->mapping); + page_cache_release(pages[i]); + } + kfree(pages); +} + +static void free_async_extent_pages(struct async_extent *async_extent) +{ + int i; + + if (!async_extent->pages) + return; + + for (i = 0; i < async_extent->nr_pages; i++) { + WARN_ON(async_extent->pages[i]->mapping); + page_cache_release(async_extent->pages[i]); + } + kfree(async_extent->pages); + async_extent->nr_pages = 0; + async_extent->pages = NULL; +} + +/* + * phase two of compressed writeback. This is the ordered portion + * of the code, which only gets called in the order the work was + * queued. We walk all the async extents created by compress_file_range + * and send them down to the disk. + */ +static noinline void submit_compressed_extents(struct inode *inode, + struct async_cow *async_cow) +{ + struct async_extent *async_extent; + u64 alloc_hint = 0; + struct btrfs_key ins; + struct extent_map *em; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + struct extent_io_tree *io_tree; + int ret = 0; + +again: + while (!list_empty(&async_cow->extents)) { + async_extent = list_entry(async_cow->extents.next, + struct async_extent, list); + list_del(&async_extent->list); + + io_tree = &BTRFS_I(inode)->io_tree; + +retry: + /* did the compression code fall back to uncompressed IO? */ + if (!async_extent->pages) { + int page_started = 0; + unsigned long nr_written = 0; + + lock_extent(io_tree, async_extent->start, + async_extent->start + + async_extent->ram_size - 1); + + /* allocate blocks */ + ret = cow_file_range(inode, async_cow->locked_page, + async_extent->start, + async_extent->start + + async_extent->ram_size - 1, + &page_started, &nr_written, 0); + + /* JDM XXX */ + + /* + * if page_started, cow_file_range inserted an + * inline extent and took care of all the unlocking + * and IO for us. Otherwise, we need to submit + * all those pages down to the drive. + */ + if (!page_started && !ret) + extent_write_locked_range(io_tree, + inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, + btrfs_get_extent, + WB_SYNC_ALL); + else if (ret) + unlock_page(async_cow->locked_page); + kfree(async_extent); + cond_resched(); + continue; + } + + lock_extent(io_tree, async_extent->start, + async_extent->start + async_extent->ram_size - 1); + + ret = btrfs_reserve_extent(root, + async_extent->compressed_size, + async_extent->compressed_size, + 0, alloc_hint, &ins, 1, 1); + if (ret) { + free_async_extent_pages(async_extent); + + if (ret == -ENOSPC) { + unlock_extent(io_tree, async_extent->start, + async_extent->start + + async_extent->ram_size - 1); + + /* + * we need to redirty the pages if we decide to + * fallback to uncompressed IO, otherwise we + * will not submit these pages down to lower + * layers. + */ + extent_range_redirty_for_io(inode, + async_extent->start, + async_extent->start + + async_extent->ram_size - 1); + + goto retry; + } + goto out_free; + } + /* + * here we're doing allocation and writeback of the + * compressed pages + */ + btrfs_drop_extent_cache(inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, 0); + + em = alloc_extent_map(); + if (!em) { + ret = -ENOMEM; + goto out_free_reserve; + } + em->start = async_extent->start; + em->len = async_extent->ram_size; + em->orig_start = em->start; + em->mod_start = em->start; + em->mod_len = em->len; + + em->block_start = ins.objectid; + em->block_len = ins.offset; + em->orig_block_len = ins.offset; + em->ram_bytes = async_extent->ram_size; + em->bdev = root->fs_info->fs_devices->latest_bdev; + em->compress_type = async_extent->compress_type; + set_bit(EXTENT_FLAG_PINNED, &em->flags); + set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); + em->generation = -1; + + while (1) { + write_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em, 1); + write_unlock(&em_tree->lock); + if (ret != -EEXIST) { + free_extent_map(em); + break; + } + btrfs_drop_extent_cache(inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, 0); + } + + if (ret) + goto out_free_reserve; + + ret = btrfs_add_ordered_extent_compress(inode, + async_extent->start, + ins.objectid, + async_extent->ram_size, + ins.offset, + BTRFS_ORDERED_COMPRESSED, + async_extent->compress_type); + if (ret) { + btrfs_drop_extent_cache(inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, 0); + goto out_free_reserve; + } + + /* + * clear dirty, set writeback and unlock the pages. + */ + extent_clear_unlock_delalloc(inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, + NULL, EXTENT_LOCKED | EXTENT_DELALLOC, + PAGE_UNLOCK | PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK); + ret = btrfs_submit_compressed_write(inode, + async_extent->start, + async_extent->ram_size, + ins.objectid, + ins.offset, async_extent->pages, + async_extent->nr_pages); + if (ret) { + struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; + struct page *p = async_extent->pages[0]; + const u64 start = async_extent->start; + const u64 end = start + async_extent->ram_size - 1; + + p->mapping = inode->i_mapping; + tree->ops->writepage_end_io_hook(p, start, end, + NULL, 0); + p->mapping = NULL; + extent_clear_unlock_delalloc(inode, start, end, NULL, 0, + PAGE_END_WRITEBACK | + PAGE_SET_ERROR); + free_async_extent_pages(async_extent); + } + alloc_hint = ins.objectid + ins.offset; + kfree(async_extent); + cond_resched(); + } + return; +out_free_reserve: + btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); +out_free: + extent_clear_unlock_delalloc(inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, + NULL, EXTENT_LOCKED | EXTENT_DELALLOC | + EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING, + PAGE_UNLOCK | PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK | + PAGE_SET_ERROR); + free_async_extent_pages(async_extent); + kfree(async_extent); + goto again; +} + +static u64 get_extent_allocation_hint(struct inode *inode, u64 start, + u64 num_bytes) +{ + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + struct extent_map *em; + u64 alloc_hint = 0; + + read_lock(&em_tree->lock); + em = search_extent_mapping(em_tree, start, num_bytes); + if (em) { + /* + * if block start isn't an actual block number then find the + * first block in this inode and use that as a hint. If that + * block is also bogus then just don't worry about it. + */ + if (em->block_start >= EXTENT_MAP_LAST_BYTE) { + free_extent_map(em); + em = search_extent_mapping(em_tree, 0, 0); + if (em && em->block_start < EXTENT_MAP_LAST_BYTE) + alloc_hint = em->block_start; + if (em) + free_extent_map(em); + } else { + alloc_hint = em->block_start; + free_extent_map(em); + } + } + read_unlock(&em_tree->lock); + + return alloc_hint; +} + +/* + * when extent_io.c finds a delayed allocation range in the file, + * the call backs end up in this code. The basic idea is to + * allocate extents on disk for the range, and create ordered data structs + * in ram to track those extents. + * + * locked_page is the page that writepage had locked already. We use + * it to make sure we don't do extra locks or unlocks. + * + * *page_started is set to one if we unlock locked_page and do everything + * required to start IO on it. It may be clean and already done with + * IO when we return. + */ +static noinline int cow_file_range(struct inode *inode, + struct page *locked_page, + u64 start, u64 end, int *page_started, + unsigned long *nr_written, + int unlock) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + u64 alloc_hint = 0; + u64 num_bytes; + unsigned long ram_size; + u64 disk_num_bytes; + u64 cur_alloc_size; + u64 blocksize = root->sectorsize; + struct btrfs_key ins; + struct extent_map *em; + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + int ret = 0; + + if (btrfs_is_free_space_inode(inode)) { + WARN_ON_ONCE(1); + ret = -EINVAL; + goto out_unlock; + } + + num_bytes = ALIGN(end - start + 1, blocksize); + num_bytes = max(blocksize, num_bytes); + disk_num_bytes = num_bytes; + + /* if this is a small write inside eof, kick off defrag */ + if (num_bytes < 64 * 1024 && + (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) + btrfs_add_inode_defrag(NULL, inode); + + if (start == 0) { + /* lets try to make an inline extent */ + ret = cow_file_range_inline(root, inode, start, end, 0, 0, + NULL); + if (ret == 0) { + extent_clear_unlock_delalloc(inode, start, end, NULL, + EXTENT_LOCKED | EXTENT_DELALLOC | + EXTENT_DEFRAG, PAGE_UNLOCK | + PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | + PAGE_END_WRITEBACK); + + *nr_written = *nr_written + + (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE; + *page_started = 1; + goto out; + } else if (ret < 0) { + goto out_unlock; + } + } + + BUG_ON(disk_num_bytes > + btrfs_super_total_bytes(root->fs_info->super_copy)); + + alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); + btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0); + + while (disk_num_bytes > 0) { + unsigned long op; + + cur_alloc_size = disk_num_bytes; + ret = btrfs_reserve_extent(root, cur_alloc_size, + root->sectorsize, 0, alloc_hint, + &ins, 1, 1); + if (ret < 0) + goto out_unlock; + + em = alloc_extent_map(); + if (!em) { + ret = -ENOMEM; + goto out_reserve; + } + em->start = start; + em->orig_start = em->start; + ram_size = ins.offset; + em->len = ins.offset; + em->mod_start = em->start; + em->mod_len = em->len; + + em->block_start = ins.objectid; + em->block_len = ins.offset; + em->orig_block_len = ins.offset; + em->ram_bytes = ram_size; + em->bdev = root->fs_info->fs_devices->latest_bdev; + set_bit(EXTENT_FLAG_PINNED, &em->flags); + em->generation = -1; + + while (1) { + write_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em, 1); + write_unlock(&em_tree->lock); + if (ret != -EEXIST) { + free_extent_map(em); + break; + } + btrfs_drop_extent_cache(inode, start, + start + ram_size - 1, 0); + } + if (ret) + goto out_reserve; + + cur_alloc_size = ins.offset; + ret = btrfs_add_ordered_extent(inode, start, ins.objectid, + ram_size, cur_alloc_size, 0); + if (ret) + goto out_drop_extent_cache; + + if (root->root_key.objectid == + BTRFS_DATA_RELOC_TREE_OBJECTID) { + ret = btrfs_reloc_clone_csums(inode, start, + cur_alloc_size); + if (ret) + goto out_drop_extent_cache; + } + + if (disk_num_bytes < cur_alloc_size) + break; + + /* we're not doing compressed IO, don't unlock the first + * page (which the caller expects to stay locked), don't + * clear any dirty bits and don't set any writeback bits + * + * Do set the Private2 bit so we know this page was properly + * setup for writepage + */ + op = unlock ? PAGE_UNLOCK : 0; + op |= PAGE_SET_PRIVATE2; + + extent_clear_unlock_delalloc(inode, start, + start + ram_size - 1, locked_page, + EXTENT_LOCKED | EXTENT_DELALLOC, + op); + disk_num_bytes -= cur_alloc_size; + num_bytes -= cur_alloc_size; + alloc_hint = ins.objectid + ins.offset; + start += cur_alloc_size; + } +out: + return ret; + +out_drop_extent_cache: + btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0); +out_reserve: + btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); +out_unlock: + extent_clear_unlock_delalloc(inode, start, end, locked_page, + EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | + EXTENT_DELALLOC | EXTENT_DEFRAG, + PAGE_UNLOCK | PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); + goto out; +} + +/* + * work queue call back to started compression on a file and pages + */ +static noinline void async_cow_start(struct btrfs_work *work) +{ + struct async_cow *async_cow; + int num_added = 0; + async_cow = container_of(work, struct async_cow, work); + + compress_file_range(async_cow->inode, async_cow->locked_page, + async_cow->start, async_cow->end, async_cow, + &num_added); + if (num_added == 0) { + btrfs_add_delayed_iput(async_cow->inode); + async_cow->inode = NULL; + } +} + +/* + * work queue call back to submit previously compressed pages + */ +static noinline void async_cow_submit(struct btrfs_work *work) +{ + struct async_cow *async_cow; + struct btrfs_root *root; + unsigned long nr_pages; + + async_cow = container_of(work, struct async_cow, work); + + root = async_cow->root; + nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >> + PAGE_CACHE_SHIFT; + + if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) < + 5 * 1024 * 1024 && + waitqueue_active(&root->fs_info->async_submit_wait)) + wake_up(&root->fs_info->async_submit_wait); + + if (async_cow->inode) + submit_compressed_extents(async_cow->inode, async_cow); +} + +static noinline void async_cow_free(struct btrfs_work *work) +{ + struct async_cow *async_cow; + async_cow = container_of(work, struct async_cow, work); + if (async_cow->inode) + btrfs_add_delayed_iput(async_cow->inode); + kfree(async_cow); +} + +static int cow_file_range_async(struct inode *inode, struct page *locked_page, + u64 start, u64 end, int *page_started, + unsigned long *nr_written) +{ + struct async_cow *async_cow; + struct btrfs_root *root = BTRFS_I(inode)->root; + unsigned long nr_pages; + u64 cur_end; + int limit = 10 * 1024 * 1024; + + clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED, + 1, 0, NULL, GFP_NOFS); + while (start < end) { + async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS); + BUG_ON(!async_cow); /* -ENOMEM */ + async_cow->inode = igrab(inode); + async_cow->root = root; + async_cow->locked_page = locked_page; + async_cow->start = start; + + if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS && + !btrfs_test_opt(root, FORCE_COMPRESS)) + cur_end = end; + else + cur_end = min(end, start + 512 * 1024 - 1); + + async_cow->end = cur_end; + INIT_LIST_HEAD(&async_cow->extents); + + btrfs_init_work(&async_cow->work, + btrfs_delalloc_helper, + async_cow_start, async_cow_submit, + async_cow_free); + + nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >> + PAGE_CACHE_SHIFT; + atomic_add(nr_pages, &root->fs_info->async_delalloc_pages); + + btrfs_queue_work(root->fs_info->delalloc_workers, + &async_cow->work); + + if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) { + wait_event(root->fs_info->async_submit_wait, + (atomic_read(&root->fs_info->async_delalloc_pages) < + limit)); + } + + while (atomic_read(&root->fs_info->async_submit_draining) && + atomic_read(&root->fs_info->async_delalloc_pages)) { + wait_event(root->fs_info->async_submit_wait, + (atomic_read(&root->fs_info->async_delalloc_pages) == + 0)); + } + + *nr_written += nr_pages; + start = cur_end + 1; + } + *page_started = 1; + return 0; +} + +static noinline int csum_exist_in_range(struct btrfs_root *root, + u64 bytenr, u64 num_bytes) +{ + int ret; + struct btrfs_ordered_sum *sums; + LIST_HEAD(list); + + ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr, + bytenr + num_bytes - 1, &list, 0); + if (ret == 0 && list_empty(&list)) + return 0; + + while (!list_empty(&list)) { + sums = list_entry(list.next, struct btrfs_ordered_sum, list); + list_del(&sums->list); + kfree(sums); + } + return 1; +} + +/* + * when nowcow writeback call back. This checks for snapshots or COW copies + * of the extents that exist in the file, and COWs the file as required. + * + * If no cow copies or snapshots exist, we write directly to the existing + * blocks on disk + */ +static noinline int run_delalloc_nocow(struct inode *inode, + struct page *locked_page, + u64 start, u64 end, int *page_started, int force, + unsigned long *nr_written) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + struct extent_buffer *leaf; + struct btrfs_path *path; + struct btrfs_file_extent_item *fi; + struct btrfs_key found_key; + u64 cow_start; + u64 cur_offset; + u64 extent_end; + u64 extent_offset; + u64 disk_bytenr; + u64 num_bytes; + u64 disk_num_bytes; + u64 ram_bytes; + int extent_type; + int ret, err; + int type; + int nocow; + int check_prev = 1; + bool nolock; + u64 ino = btrfs_ino(inode); + + path = btrfs_alloc_path(); + if (!path) { + extent_clear_unlock_delalloc(inode, start, end, locked_page, + EXTENT_LOCKED | EXTENT_DELALLOC | + EXTENT_DO_ACCOUNTING | + EXTENT_DEFRAG, PAGE_UNLOCK | + PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK | + PAGE_END_WRITEBACK); + return -ENOMEM; + } + + nolock = btrfs_is_free_space_inode(inode); + + if (nolock) + trans = btrfs_join_transaction_nolock(root); + else + trans = btrfs_join_transaction(root); + + if (IS_ERR(trans)) { + extent_clear_unlock_delalloc(inode, start, end, locked_page, + EXTENT_LOCKED | EXTENT_DELALLOC | + EXTENT_DO_ACCOUNTING | + EXTENT_DEFRAG, PAGE_UNLOCK | + PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK | + PAGE_END_WRITEBACK); + btrfs_free_path(path); + return PTR_ERR(trans); + } + + trans->block_rsv = &root->fs_info->delalloc_block_rsv; + + cow_start = (u64)-1; + cur_offset = start; + while (1) { + ret = btrfs_lookup_file_extent(trans, root, path, ino, + cur_offset, 0); + if (ret < 0) + goto error; + if (ret > 0 && path->slots[0] > 0 && check_prev) { + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, + path->slots[0] - 1); + if (found_key.objectid == ino && + found_key.type == BTRFS_EXTENT_DATA_KEY) + path->slots[0]--; + } + check_prev = 0; +next_slot: + leaf = path->nodes[0]; + if (path->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto error; + if (ret > 0) + break; + leaf = path->nodes[0]; + } + + nocow = 0; + disk_bytenr = 0; + num_bytes = 0; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + if (found_key.objectid > ino || + found_key.type > BTRFS_EXTENT_DATA_KEY || + found_key.offset > end) + break; + + if (found_key.offset > cur_offset) { + extent_end = found_key.offset; + extent_type = 0; + goto out_check; + } + + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + extent_type = btrfs_file_extent_type(leaf, fi); + + ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); + if (extent_type == BTRFS_FILE_EXTENT_REG || + extent_type == BTRFS_FILE_EXTENT_PREALLOC) { + disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); + extent_offset = btrfs_file_extent_offset(leaf, fi); + extent_end = found_key.offset + + btrfs_file_extent_num_bytes(leaf, fi); + disk_num_bytes = + btrfs_file_extent_disk_num_bytes(leaf, fi); + if (extent_end <= start) { + path->slots[0]++; + goto next_slot; + } + if (disk_bytenr == 0) + goto out_check; + if (btrfs_file_extent_compression(leaf, fi) || + btrfs_file_extent_encryption(leaf, fi) || + btrfs_file_extent_other_encoding(leaf, fi)) + goto out_check; + if (extent_type == BTRFS_FILE_EXTENT_REG && !force) + goto out_check; + if (btrfs_extent_readonly(root, disk_bytenr)) + goto out_check; + if (btrfs_cross_ref_exist(trans, root, ino, + found_key.offset - + extent_offset, disk_bytenr)) + goto out_check; + disk_bytenr += extent_offset; + disk_bytenr += cur_offset - found_key.offset; + num_bytes = min(end + 1, extent_end) - cur_offset; + /* + * if there are pending snapshots for this root, + * we fall into common COW way. + */ + if (!nolock) { + err = btrfs_start_write_no_snapshoting(root); + if (!err) + goto out_check; + } + /* + * force cow if csum exists in the range. + * this ensure that csum for a given extent are + * either valid or do not exist. + */ + if (csum_exist_in_range(root, disk_bytenr, num_bytes)) + goto out_check; + nocow = 1; + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + extent_end = found_key.offset + + btrfs_file_extent_inline_len(leaf, + path->slots[0], fi); + extent_end = ALIGN(extent_end, root->sectorsize); + } else { + BUG_ON(1); + } +out_check: + if (extent_end <= start) { + path->slots[0]++; + if (!nolock && nocow) + btrfs_end_write_no_snapshoting(root); + goto next_slot; + } + if (!nocow) { + if (cow_start == (u64)-1) + cow_start = cur_offset; + cur_offset = extent_end; + if (cur_offset > end) + break; + path->slots[0]++; + goto next_slot; + } + + btrfs_release_path(path); + if (cow_start != (u64)-1) { + ret = cow_file_range(inode, locked_page, + cow_start, found_key.offset - 1, + page_started, nr_written, 1); + if (ret) { + if (!nolock && nocow) + btrfs_end_write_no_snapshoting(root); + goto error; + } + cow_start = (u64)-1; + } + + if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { + struct extent_map *em; + struct extent_map_tree *em_tree; + em_tree = &BTRFS_I(inode)->extent_tree; + em = alloc_extent_map(); + BUG_ON(!em); /* -ENOMEM */ + em->start = cur_offset; + em->orig_start = found_key.offset - extent_offset; + em->len = num_bytes; + em->block_len = num_bytes; + em->block_start = disk_bytenr; + em->orig_block_len = disk_num_bytes; + em->ram_bytes = ram_bytes; + em->bdev = root->fs_info->fs_devices->latest_bdev; + em->mod_start = em->start; + em->mod_len = em->len; + set_bit(EXTENT_FLAG_PINNED, &em->flags); + set_bit(EXTENT_FLAG_FILLING, &em->flags); + em->generation = -1; + while (1) { + write_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em, 1); + write_unlock(&em_tree->lock); + if (ret != -EEXIST) { + free_extent_map(em); + break; + } + btrfs_drop_extent_cache(inode, em->start, + em->start + em->len - 1, 0); + } + type = BTRFS_ORDERED_PREALLOC; + } else { + type = BTRFS_ORDERED_NOCOW; + } + + ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr, + num_bytes, num_bytes, type); + BUG_ON(ret); /* -ENOMEM */ + + if (root->root_key.objectid == + BTRFS_DATA_RELOC_TREE_OBJECTID) { + ret = btrfs_reloc_clone_csums(inode, cur_offset, + num_bytes); + if (ret) { + if (!nolock && nocow) + btrfs_end_write_no_snapshoting(root); + goto error; + } + } + + extent_clear_unlock_delalloc(inode, cur_offset, + cur_offset + num_bytes - 1, + locked_page, EXTENT_LOCKED | + EXTENT_DELALLOC, PAGE_UNLOCK | + PAGE_SET_PRIVATE2); + if (!nolock && nocow) + btrfs_end_write_no_snapshoting(root); + cur_offset = extent_end; + if (cur_offset > end) + break; + } + btrfs_release_path(path); + + if (cur_offset <= end && cow_start == (u64)-1) { + cow_start = cur_offset; + cur_offset = end; + } + + if (cow_start != (u64)-1) { + ret = cow_file_range(inode, locked_page, cow_start, end, + page_started, nr_written, 1); + if (ret) + goto error; + } + +error: + err = btrfs_end_transaction(trans, root); + if (!ret) + ret = err; + + if (ret && cur_offset < end) + extent_clear_unlock_delalloc(inode, cur_offset, end, + locked_page, EXTENT_LOCKED | + EXTENT_DELALLOC | EXTENT_DEFRAG | + EXTENT_DO_ACCOUNTING, PAGE_UNLOCK | + PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK | + PAGE_END_WRITEBACK); + btrfs_free_path(path); + return ret; +} + +static inline int need_force_cow(struct inode *inode, u64 start, u64 end) +{ + + if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && + !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)) + return 0; + + /* + * @defrag_bytes is a hint value, no spinlock held here, + * if is not zero, it means the file is defragging. + * Force cow if given extent needs to be defragged. + */ + if (BTRFS_I(inode)->defrag_bytes && + test_range_bit(&BTRFS_I(inode)->io_tree, start, end, + EXTENT_DEFRAG, 0, NULL)) + return 1; + + return 0; +} + +/* + * extent_io.c call back to do delayed allocation processing + */ +static int run_delalloc_range(struct inode *inode, struct page *locked_page, + u64 start, u64 end, int *page_started, + unsigned long *nr_written) +{ + int ret; + int force_cow = need_force_cow(inode, start, end); + + if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) { + ret = run_delalloc_nocow(inode, locked_page, start, end, + page_started, 1, nr_written); + } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) { + ret = run_delalloc_nocow(inode, locked_page, start, end, + page_started, 0, nr_written); + } else if (!inode_need_compress(inode)) { + ret = cow_file_range(inode, locked_page, start, end, + page_started, nr_written, 1); + } else { + set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, + &BTRFS_I(inode)->runtime_flags); + ret = cow_file_range_async(inode, locked_page, start, end, + page_started, nr_written); + } + return ret; +} + +static void btrfs_split_extent_hook(struct inode *inode, + struct extent_state *orig, u64 split) +{ + u64 size; + + /* not delalloc, ignore it */ + if (!(orig->state & EXTENT_DELALLOC)) + return; + + size = orig->end - orig->start + 1; + if (size > BTRFS_MAX_EXTENT_SIZE) { + u64 num_extents; + u64 new_size; + + /* + * See the explanation in btrfs_merge_extent_hook, the same + * applies here, just in reverse. + */ + new_size = orig->end - split + 1; + num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1, + BTRFS_MAX_EXTENT_SIZE); + new_size = split - orig->start; + num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1, + BTRFS_MAX_EXTENT_SIZE); + if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1, + BTRFS_MAX_EXTENT_SIZE) >= num_extents) + return; + } + + spin_lock(&BTRFS_I(inode)->lock); + BTRFS_I(inode)->outstanding_extents++; + spin_unlock(&BTRFS_I(inode)->lock); +} + +/* + * extent_io.c merge_extent_hook, used to track merged delayed allocation + * extents so we can keep track of new extents that are just merged onto old + * extents, such as when we are doing sequential writes, so we can properly + * account for the metadata space we'll need. + */ +static void btrfs_merge_extent_hook(struct inode *inode, + struct extent_state *new, + struct extent_state *other) +{ + u64 new_size, old_size; + u64 num_extents; + + /* not delalloc, ignore it */ + if (!(other->state & EXTENT_DELALLOC)) + return; + + if (new->start > other->start) + new_size = new->end - other->start + 1; + else + new_size = other->end - new->start + 1; + + /* we're not bigger than the max, unreserve the space and go */ + if (new_size <= BTRFS_MAX_EXTENT_SIZE) { + spin_lock(&BTRFS_I(inode)->lock); + BTRFS_I(inode)->outstanding_extents--; + spin_unlock(&BTRFS_I(inode)->lock); + return; + } + + /* + * We have to add up either side to figure out how many extents were + * accounted for before we merged into one big extent. If the number of + * extents we accounted for is <= the amount we need for the new range + * then we can return, otherwise drop. Think of it like this + * + * [ 4k][MAX_SIZE] + * + * So we've grown the extent by a MAX_SIZE extent, this would mean we + * need 2 outstanding extents, on one side we have 1 and the other side + * we have 1 so they are == and we can return. But in this case + * + * [MAX_SIZE+4k][MAX_SIZE+4k] + * + * Each range on their own accounts for 2 extents, but merged together + * they are only 3 extents worth of accounting, so we need to drop in + * this case. + */ + old_size = other->end - other->start + 1; + num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1, + BTRFS_MAX_EXTENT_SIZE); + old_size = new->end - new->start + 1; + num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1, + BTRFS_MAX_EXTENT_SIZE); + + if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1, + BTRFS_MAX_EXTENT_SIZE) >= num_extents) + return; + + spin_lock(&BTRFS_I(inode)->lock); + BTRFS_I(inode)->outstanding_extents--; + spin_unlock(&BTRFS_I(inode)->lock); +} + +static void btrfs_add_delalloc_inodes(struct btrfs_root *root, + struct inode *inode) +{ + spin_lock(&root->delalloc_lock); + if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) { + list_add_tail(&BTRFS_I(inode)->delalloc_inodes, + &root->delalloc_inodes); + set_bit(BTRFS_INODE_IN_DELALLOC_LIST, + &BTRFS_I(inode)->runtime_flags); + root->nr_delalloc_inodes++; + if (root->nr_delalloc_inodes == 1) { + spin_lock(&root->fs_info->delalloc_root_lock); + BUG_ON(!list_empty(&root->delalloc_root)); + list_add_tail(&root->delalloc_root, + &root->fs_info->delalloc_roots); + spin_unlock(&root->fs_info->delalloc_root_lock); + } + } + spin_unlock(&root->delalloc_lock); +} + +static void btrfs_del_delalloc_inode(struct btrfs_root *root, + struct inode *inode) +{ + spin_lock(&root->delalloc_lock); + if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) { + list_del_init(&BTRFS_I(inode)->delalloc_inodes); + clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, + &BTRFS_I(inode)->runtime_flags); + root->nr_delalloc_inodes--; + if (!root->nr_delalloc_inodes) { + spin_lock(&root->fs_info->delalloc_root_lock); + BUG_ON(list_empty(&root->delalloc_root)); + list_del_init(&root->delalloc_root); + spin_unlock(&root->fs_info->delalloc_root_lock); + } + } + spin_unlock(&root->delalloc_lock); +} + +/* + * extent_io.c set_bit_hook, used to track delayed allocation + * bytes in this file, and to maintain the list of inodes that + * have pending delalloc work to be done. + */ +static void btrfs_set_bit_hook(struct inode *inode, + struct extent_state *state, unsigned *bits) +{ + + if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC)) + WARN_ON(1); + /* + * set_bit and clear bit hooks normally require _irqsave/restore + * but in this case, we are only testing for the DELALLOC + * bit, which is only set or cleared with irqs on + */ + if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { + struct btrfs_root *root = BTRFS_I(inode)->root; + u64 len = state->end + 1 - state->start; + bool do_list = !btrfs_is_free_space_inode(inode); + + if (*bits & EXTENT_FIRST_DELALLOC) { + *bits &= ~EXTENT_FIRST_DELALLOC; + } else { + spin_lock(&BTRFS_I(inode)->lock); + BTRFS_I(inode)->outstanding_extents++; + spin_unlock(&BTRFS_I(inode)->lock); + } + + /* For sanity tests */ + if (btrfs_test_is_dummy_root(root)) + return; + + __percpu_counter_add(&root->fs_info->delalloc_bytes, len, + root->fs_info->delalloc_batch); + spin_lock(&BTRFS_I(inode)->lock); + BTRFS_I(inode)->delalloc_bytes += len; + if (*bits & EXTENT_DEFRAG) + BTRFS_I(inode)->defrag_bytes += len; + if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST, + &BTRFS_I(inode)->runtime_flags)) + btrfs_add_delalloc_inodes(root, inode); + spin_unlock(&BTRFS_I(inode)->lock); + } +} + +/* + * extent_io.c clear_bit_hook, see set_bit_hook for why + */ +static void btrfs_clear_bit_hook(struct inode *inode, + struct extent_state *state, + unsigned *bits) +{ + u64 len = state->end + 1 - state->start; + u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1, + BTRFS_MAX_EXTENT_SIZE); + + spin_lock(&BTRFS_I(inode)->lock); + if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) + BTRFS_I(inode)->defrag_bytes -= len; + spin_unlock(&BTRFS_I(inode)->lock); + + /* + * set_bit and clear bit hooks normally require _irqsave/restore + * but in this case, we are only testing for the DELALLOC + * bit, which is only set or cleared with irqs on + */ + if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { + struct btrfs_root *root = BTRFS_I(inode)->root; + bool do_list = !btrfs_is_free_space_inode(inode); + + if (*bits & EXTENT_FIRST_DELALLOC) { + *bits &= ~EXTENT_FIRST_DELALLOC; + } else if (!(*bits & EXTENT_DO_ACCOUNTING)) { + spin_lock(&BTRFS_I(inode)->lock); + BTRFS_I(inode)->outstanding_extents -= num_extents; + spin_unlock(&BTRFS_I(inode)->lock); + } + + /* + * We don't reserve metadata space for space cache inodes so we + * don't need to call dellalloc_release_metadata if there is an + * error. + */ + if (*bits & EXTENT_DO_ACCOUNTING && + root != root->fs_info->tree_root) + btrfs_delalloc_release_metadata(inode, len); + + /* For sanity tests. */ + if (btrfs_test_is_dummy_root(root)) + return; + + if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID + && do_list && !(state->state & EXTENT_NORESERVE)) + btrfs_free_reserved_data_space(inode, len); + + __percpu_counter_add(&root->fs_info->delalloc_bytes, -len, + root->fs_info->delalloc_batch); + spin_lock(&BTRFS_I(inode)->lock); + BTRFS_I(inode)->delalloc_bytes -= len; + if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 && + test_bit(BTRFS_INODE_IN_DELALLOC_LIST, + &BTRFS_I(inode)->runtime_flags)) + btrfs_del_delalloc_inode(root, inode); + spin_unlock(&BTRFS_I(inode)->lock); + } +} + +/* + * extent_io.c merge_bio_hook, this must check the chunk tree to make sure + * we don't create bios that span stripes or chunks + */ +int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset, + size_t size, struct bio *bio, + unsigned long bio_flags) +{ + struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; + u64 logical = (u64)bio->bi_iter.bi_sector << 9; + u64 length = 0; + u64 map_length; + int ret; + + if (bio_flags & EXTENT_BIO_COMPRESSED) + return 0; + + length = bio->bi_iter.bi_size; + map_length = length; + ret = btrfs_map_block(root->fs_info, rw, logical, + &map_length, NULL, 0); + /* Will always return 0 with map_multi == NULL */ + BUG_ON(ret < 0); + if (map_length < length + size) + return 1; + return 0; +} + +/* + * in order to insert checksums into the metadata in large chunks, + * we wait until bio submission time. All the pages in the bio are + * checksummed and sums are attached onto the ordered extent record. + * + * At IO completion time the cums attached on the ordered extent record + * are inserted into the btree + */ +static int __btrfs_submit_bio_start(struct inode *inode, int rw, + struct bio *bio, int mirror_num, + unsigned long bio_flags, + u64 bio_offset) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret = 0; + + ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); + BUG_ON(ret); /* -ENOMEM */ + return 0; +} + +/* + * in order to insert checksums into the metadata in large chunks, + * we wait until bio submission time. All the pages in the bio are + * checksummed and sums are attached onto the ordered extent record. + * + * At IO completion time the cums attached on the ordered extent record + * are inserted into the btree + */ +static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio, + int mirror_num, unsigned long bio_flags, + u64 bio_offset) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret; + + ret = btrfs_map_bio(root, rw, bio, mirror_num, 1); + if (ret) + bio_endio(bio, ret); + return ret; +} + +/* + * extent_io.c submission hook. This does the right thing for csum calculation + * on write, or reading the csums from the tree before a read + */ +static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, + int mirror_num, unsigned long bio_flags, + u64 bio_offset) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret = 0; + int skip_sum; + int metadata = 0; + int async = !atomic_read(&BTRFS_I(inode)->sync_writers); + + skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; + + if (btrfs_is_free_space_inode(inode)) + metadata = 2; + + if (!(rw & REQ_WRITE)) { + ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata); + if (ret) + goto out; + + if (bio_flags & EXTENT_BIO_COMPRESSED) { + ret = btrfs_submit_compressed_read(inode, bio, + mirror_num, + bio_flags); + goto out; + } else if (!skip_sum) { + ret = btrfs_lookup_bio_sums(root, inode, bio, NULL); + if (ret) + goto out; + } + goto mapit; + } else if (async && !skip_sum) { + /* csum items have already been cloned */ + if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) + goto mapit; + /* we're doing a write, do the async checksumming */ + ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, + inode, rw, bio, mirror_num, + bio_flags, bio_offset, + __btrfs_submit_bio_start, + __btrfs_submit_bio_done); + goto out; + } else if (!skip_sum) { + ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); + if (ret) + goto out; + } + +mapit: + ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); + +out: + if (ret < 0) + bio_endio(bio, ret); + return ret; +} + +/* + * given a list of ordered sums record them in the inode. This happens + * at IO completion time based on sums calculated at bio submission time. + */ +static noinline int add_pending_csums(struct btrfs_trans_handle *trans, + struct inode *inode, u64 file_offset, + struct list_head *list) +{ + struct btrfs_ordered_sum *sum; + + list_for_each_entry(sum, list, list) { + trans->adding_csums = 1; + btrfs_csum_file_blocks(trans, + BTRFS_I(inode)->root->fs_info->csum_root, sum); + trans->adding_csums = 0; + } + return 0; +} + +int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end, + struct extent_state **cached_state) +{ + WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0); + return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end, + cached_state, GFP_NOFS); +} + +/* see btrfs_writepage_start_hook for details on why this is required */ +struct btrfs_writepage_fixup { + struct page *page; + struct btrfs_work work; +}; + +static void btrfs_writepage_fixup_worker(struct btrfs_work *work) +{ + struct btrfs_writepage_fixup *fixup; + struct btrfs_ordered_extent *ordered; + struct extent_state *cached_state = NULL; + struct page *page; + struct inode *inode; + u64 page_start; + u64 page_end; + int ret; + + fixup = container_of(work, struct btrfs_writepage_fixup, work); + page = fixup->page; +again: + lock_page(page); + if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { + ClearPageChecked(page); + goto out_page; + } + + inode = page->mapping->host; + page_start = page_offset(page); + page_end = page_offset(page) + PAGE_CACHE_SIZE - 1; + + lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0, + &cached_state); + + /* already ordered? We're done */ + if (PagePrivate2(page)) + goto out; + + ordered = btrfs_lookup_ordered_extent(inode, page_start); + if (ordered) { + unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, + page_end, &cached_state, GFP_NOFS); + unlock_page(page); + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + goto again; + } + + ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); + if (ret) { + mapping_set_error(page->mapping, ret); + end_extent_writepage(page, ret, page_start, page_end); + ClearPageChecked(page); + goto out; + } + + btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); + ClearPageChecked(page); + set_page_dirty(page); +out: + unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, + &cached_state, GFP_NOFS); +out_page: + unlock_page(page); + page_cache_release(page); + kfree(fixup); +} + +/* + * There are a few paths in the higher layers of the kernel that directly + * set the page dirty bit without asking the filesystem if it is a + * good idea. This causes problems because we want to make sure COW + * properly happens and the data=ordered rules are followed. + * + * In our case any range that doesn't have the ORDERED bit set + * hasn't been properly setup for IO. We kick off an async process + * to fix it up. The async helper will wait for ordered extents, set + * the delalloc bit and make it safe to write the page. + */ +static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end) +{ + struct inode *inode = page->mapping->host; + struct btrfs_writepage_fixup *fixup; + struct btrfs_root *root = BTRFS_I(inode)->root; + + /* this page is properly in the ordered list */ + if (TestClearPagePrivate2(page)) + return 0; + + if (PageChecked(page)) + return -EAGAIN; + + fixup = kzalloc(sizeof(*fixup), GFP_NOFS); + if (!fixup) + return -EAGAIN; + + SetPageChecked(page); + page_cache_get(page); + btrfs_init_work(&fixup->work, btrfs_fixup_helper, + btrfs_writepage_fixup_worker, NULL, NULL); + fixup->page = page; + btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work); + return -EBUSY; +} + +static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, + struct inode *inode, u64 file_pos, + u64 disk_bytenr, u64 disk_num_bytes, + u64 num_bytes, u64 ram_bytes, + u8 compression, u8 encryption, + u16 other_encoding, int extent_type) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_file_extent_item *fi; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_key ins; + int extent_inserted = 0; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + /* + * we may be replacing one extent in the tree with another. + * The new extent is pinned in the extent map, and we don't want + * to drop it from the cache until it is completely in the btree. + * + * So, tell btrfs_drop_extents to leave this extent in the cache. + * the caller is expected to unpin it and allow it to be merged + * with the others. + */ + ret = __btrfs_drop_extents(trans, root, inode, path, file_pos, + file_pos + num_bytes, NULL, 0, + 1, sizeof(*fi), &extent_inserted); + if (ret) + goto out; + + if (!extent_inserted) { + ins.objectid = btrfs_ino(inode); + ins.offset = file_pos; + ins.type = BTRFS_EXTENT_DATA_KEY; + + path->leave_spinning = 1; + ret = btrfs_insert_empty_item(trans, root, path, &ins, + sizeof(*fi)); + if (ret) + goto out; + } + leaf = path->nodes[0]; + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + btrfs_set_file_extent_generation(leaf, fi, trans->transid); + btrfs_set_file_extent_type(leaf, fi, extent_type); + btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr); + btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes); + btrfs_set_file_extent_offset(leaf, fi, 0); + btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); + btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes); + btrfs_set_file_extent_compression(leaf, fi, compression); + btrfs_set_file_extent_encryption(leaf, fi, encryption); + btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding); + + btrfs_mark_buffer_dirty(leaf); + btrfs_release_path(path); + + inode_add_bytes(inode, num_bytes); + + ins.objectid = disk_bytenr; + ins.offset = disk_num_bytes; + ins.type = BTRFS_EXTENT_ITEM_KEY; + ret = btrfs_alloc_reserved_file_extent(trans, root, + root->root_key.objectid, + btrfs_ino(inode), file_pos, &ins); +out: + btrfs_free_path(path); + + return ret; +} + +/* snapshot-aware defrag */ +struct sa_defrag_extent_backref { + struct rb_node node; + struct old_sa_defrag_extent *old; + u64 root_id; + u64 inum; + u64 file_pos; + u64 extent_offset; + u64 num_bytes; + u64 generation; +}; + +struct old_sa_defrag_extent { + struct list_head list; + struct new_sa_defrag_extent *new; + + u64 extent_offset; + u64 bytenr; + u64 offset; + u64 len; + int count; +}; + +struct new_sa_defrag_extent { + struct rb_root root; + struct list_head head; + struct btrfs_path *path; + struct inode *inode; + u64 file_pos; + u64 len; + u64 bytenr; + u64 disk_len; + u8 compress_type; +}; + +static int backref_comp(struct sa_defrag_extent_backref *b1, + struct sa_defrag_extent_backref *b2) +{ + if (b1->root_id < b2->root_id) + return -1; + else if (b1->root_id > b2->root_id) + return 1; + + if (b1->inum < b2->inum) + return -1; + else if (b1->inum > b2->inum) + return 1; + + if (b1->file_pos < b2->file_pos) + return -1; + else if (b1->file_pos > b2->file_pos) + return 1; + + /* + * [------------------------------] ===> (a range of space) + * |<--->| |<---->| =============> (fs/file tree A) + * |<---------------------------->| ===> (fs/file tree B) + * + * A range of space can refer to two file extents in one tree while + * refer to only one file extent in another tree. + * + * So we may process a disk offset more than one time(two extents in A) + * and locate at the same extent(one extent in B), then insert two same + * backrefs(both refer to the extent in B). + */ + return 0; +} + +static void backref_insert(struct rb_root *root, + struct sa_defrag_extent_backref *backref) +{ + struct rb_node **p = &root->rb_node; + struct rb_node *parent = NULL; + struct sa_defrag_extent_backref *entry; + int ret; + + while (*p) { + parent = *p; + entry = rb_entry(parent, struct sa_defrag_extent_backref, node); + + ret = backref_comp(backref, entry); + if (ret < 0) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + + rb_link_node(&backref->node, parent, p); + rb_insert_color(&backref->node, root); +} + +/* + * Note the backref might has changed, and in this case we just return 0. + */ +static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id, + void *ctx) +{ + struct btrfs_file_extent_item *extent; + struct btrfs_fs_info *fs_info; + struct old_sa_defrag_extent *old = ctx; + struct new_sa_defrag_extent *new = old->new; + struct btrfs_path *path = new->path; + struct btrfs_key key; + struct btrfs_root *root; + struct sa_defrag_extent_backref *backref; + struct extent_buffer *leaf; + struct inode *inode = new->inode; + int slot; + int ret; + u64 extent_offset; + u64 num_bytes; + + if (BTRFS_I(inode)->root->root_key.objectid == root_id && + inum == btrfs_ino(inode)) + return 0; + + key.objectid = root_id; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + + fs_info = BTRFS_I(inode)->root->fs_info; + root = btrfs_read_fs_root_no_name(fs_info, &key); + if (IS_ERR(root)) { + if (PTR_ERR(root) == -ENOENT) + return 0; + WARN_ON(1); + pr_debug("inum=%llu, offset=%llu, root_id=%llu\n", + inum, offset, root_id); + return PTR_ERR(root); + } + + key.objectid = inum; + key.type = BTRFS_EXTENT_DATA_KEY; + if (offset > (u64)-1 << 32) + key.offset = 0; + else + key.offset = offset; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (WARN_ON(ret < 0)) + return ret; + ret = 0; + + while (1) { + cond_resched(); + + leaf = path->nodes[0]; + slot = path->slots[0]; + + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) { + goto out; + } else if (ret > 0) { + ret = 0; + goto out; + } + continue; + } + + path->slots[0]++; + + btrfs_item_key_to_cpu(leaf, &key, slot); + + if (key.objectid > inum) + goto out; + + if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY) + continue; + + extent = btrfs_item_ptr(leaf, slot, + struct btrfs_file_extent_item); + + if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr) + continue; + + /* + * 'offset' refers to the exact key.offset, + * NOT the 'offset' field in btrfs_extent_data_ref, ie. + * (key.offset - extent_offset). + */ + if (key.offset != offset) + continue; + + extent_offset = btrfs_file_extent_offset(leaf, extent); + num_bytes = btrfs_file_extent_num_bytes(leaf, extent); + + if (extent_offset >= old->extent_offset + old->offset + + old->len || extent_offset + num_bytes <= + old->extent_offset + old->offset) + continue; + break; + } + + backref = kmalloc(sizeof(*backref), GFP_NOFS); + if (!backref) { + ret = -ENOENT; + goto out; + } + + backref->root_id = root_id; + backref->inum = inum; + backref->file_pos = offset; + backref->num_bytes = num_bytes; + backref->extent_offset = extent_offset; + backref->generation = btrfs_file_extent_generation(leaf, extent); + backref->old = old; + backref_insert(&new->root, backref); + old->count++; +out: + btrfs_release_path(path); + WARN_ON(ret); + return ret; +} + +static noinline bool record_extent_backrefs(struct btrfs_path *path, + struct new_sa_defrag_extent *new) +{ + struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info; + struct old_sa_defrag_extent *old, *tmp; + int ret; + + new->path = path; + + list_for_each_entry_safe(old, tmp, &new->head, list) { + ret = iterate_inodes_from_logical(old->bytenr + + old->extent_offset, fs_info, + path, record_one_backref, + old); + if (ret < 0 && ret != -ENOENT) + return false; + + /* no backref to be processed for this extent */ + if (!old->count) { + list_del(&old->list); + kfree(old); + } + } + + if (list_empty(&new->head)) + return false; + + return true; +} + +static int relink_is_mergable(struct extent_buffer *leaf, + struct btrfs_file_extent_item *fi, + struct new_sa_defrag_extent *new) +{ + if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr) + return 0; + + if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) + return 0; + + if (btrfs_file_extent_compression(leaf, fi) != new->compress_type) + return 0; + + if (btrfs_file_extent_encryption(leaf, fi) || + btrfs_file_extent_other_encoding(leaf, fi)) + return 0; + + return 1; +} + +/* + * Note the backref might has changed, and in this case we just return 0. + */ +static noinline int relink_extent_backref(struct btrfs_path *path, + struct sa_defrag_extent_backref *prev, + struct sa_defrag_extent_backref *backref) +{ + struct btrfs_file_extent_item *extent; + struct btrfs_file_extent_item *item; + struct btrfs_ordered_extent *ordered; + struct btrfs_trans_handle *trans; + struct btrfs_fs_info *fs_info; + struct btrfs_root *root; + struct btrfs_key key; + struct extent_buffer *leaf; + struct old_sa_defrag_extent *old = backref->old; + struct new_sa_defrag_extent *new = old->new; + struct inode *src_inode = new->inode; + struct inode *inode; + struct extent_state *cached = NULL; + int ret = 0; + u64 start; + u64 len; + u64 lock_start; + u64 lock_end; + bool merge = false; + int index; + + if (prev && prev->root_id == backref->root_id && + prev->inum == backref->inum && + prev->file_pos + prev->num_bytes == backref->file_pos) + merge = true; + + /* step 1: get root */ + key.objectid = backref->root_id; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + + fs_info = BTRFS_I(src_inode)->root->fs_info; + index = srcu_read_lock(&fs_info->subvol_srcu); + + root = btrfs_read_fs_root_no_name(fs_info, &key); + if (IS_ERR(root)) { + srcu_read_unlock(&fs_info->subvol_srcu, index); + if (PTR_ERR(root) == -ENOENT) + return 0; + return PTR_ERR(root); + } + + if (btrfs_root_readonly(root)) { + srcu_read_unlock(&fs_info->subvol_srcu, index); + return 0; + } + + /* step 2: get inode */ + key.objectid = backref->inum; + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + + inode = btrfs_iget(fs_info->sb, &key, root, NULL); + if (IS_ERR(inode)) { + srcu_read_unlock(&fs_info->subvol_srcu, index); + return 0; + } + + srcu_read_unlock(&fs_info->subvol_srcu, index); + + /* step 3: relink backref */ + lock_start = backref->file_pos; + lock_end = backref->file_pos + backref->num_bytes - 1; + lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end, + 0, &cached); + + ordered = btrfs_lookup_first_ordered_extent(inode, lock_end); + if (ordered) { + btrfs_put_ordered_extent(ordered); + goto out_unlock; + } + + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_unlock; + } + + key.objectid = backref->inum; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = backref->file_pos; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) { + goto out_free_path; + } else if (ret > 0) { + ret = 0; + goto out_free_path; + } + + extent = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_file_extent_item); + + if (btrfs_file_extent_generation(path->nodes[0], extent) != + backref->generation) + goto out_free_path; + + btrfs_release_path(path); + + start = backref->file_pos; + if (backref->extent_offset < old->extent_offset + old->offset) + start += old->extent_offset + old->offset - + backref->extent_offset; + + len = min(backref->extent_offset + backref->num_bytes, + old->extent_offset + old->offset + old->len); + len -= max(backref->extent_offset, old->extent_offset + old->offset); + + ret = btrfs_drop_extents(trans, root, inode, start, + start + len, 1); + if (ret) + goto out_free_path; +again: + key.objectid = btrfs_ino(inode); + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = start; + + path->leave_spinning = 1; + if (merge) { + struct btrfs_file_extent_item *fi; + u64 extent_len; + struct btrfs_key found_key; + + ret = btrfs_search_slot(trans, root, &key, path, 0, 1); + if (ret < 0) + goto out_free_path; + + path->slots[0]--; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + extent_len = btrfs_file_extent_num_bytes(leaf, fi); + + if (extent_len + found_key.offset == start && + relink_is_mergable(leaf, fi, new)) { + btrfs_set_file_extent_num_bytes(leaf, fi, + extent_len + len); + btrfs_mark_buffer_dirty(leaf); + inode_add_bytes(inode, len); + + ret = 1; + goto out_free_path; + } else { + merge = false; + btrfs_release_path(path); + goto again; + } + } + + ret = btrfs_insert_empty_item(trans, root, path, &key, + sizeof(*extent)); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out_free_path; + } + + leaf = path->nodes[0]; + item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr); + btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len); + btrfs_set_file_extent_offset(leaf, item, start - new->file_pos); + btrfs_set_file_extent_num_bytes(leaf, item, len); + btrfs_set_file_extent_ram_bytes(leaf, item, new->len); + btrfs_set_file_extent_generation(leaf, item, trans->transid); + btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); + btrfs_set_file_extent_compression(leaf, item, new->compress_type); + btrfs_set_file_extent_encryption(leaf, item, 0); + btrfs_set_file_extent_other_encoding(leaf, item, 0); + + btrfs_mark_buffer_dirty(leaf); + inode_add_bytes(inode, len); + btrfs_release_path(path); + + ret = btrfs_inc_extent_ref(trans, root, new->bytenr, + new->disk_len, 0, + backref->root_id, backref->inum, + new->file_pos, 0); /* start - extent_offset */ + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out_free_path; + } + + ret = 1; +out_free_path: + btrfs_release_path(path); + path->leave_spinning = 0; + btrfs_end_transaction(trans, root); +out_unlock: + unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end, + &cached, GFP_NOFS); + iput(inode); + return ret; +} + +static void free_sa_defrag_extent(struct new_sa_defrag_extent *new) +{ + struct old_sa_defrag_extent *old, *tmp; + + if (!new) + return; + + list_for_each_entry_safe(old, tmp, &new->head, list) { + list_del(&old->list); + kfree(old); + } + kfree(new); +} + +static void relink_file_extents(struct new_sa_defrag_extent *new) +{ + struct btrfs_path *path; + struct sa_defrag_extent_backref *backref; + struct sa_defrag_extent_backref *prev = NULL; + struct inode *inode; + struct btrfs_root *root; + struct rb_node *node; + int ret; + + inode = new->inode; + root = BTRFS_I(inode)->root; + + path = btrfs_alloc_path(); + if (!path) + return; + + if (!record_extent_backrefs(path, new)) { + btrfs_free_path(path); + goto out; + } + btrfs_release_path(path); + + while (1) { + node = rb_first(&new->root); + if (!node) + break; + rb_erase(node, &new->root); + + backref = rb_entry(node, struct sa_defrag_extent_backref, node); + + ret = relink_extent_backref(path, prev, backref); + WARN_ON(ret < 0); + + kfree(prev); + + if (ret == 1) + prev = backref; + else + prev = NULL; + cond_resched(); + } + kfree(prev); + + btrfs_free_path(path); +out: + free_sa_defrag_extent(new); + + atomic_dec(&root->fs_info->defrag_running); + wake_up(&root->fs_info->transaction_wait); +} + +static struct new_sa_defrag_extent * +record_old_file_extents(struct inode *inode, + struct btrfs_ordered_extent *ordered) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_path *path; + struct btrfs_key key; + struct old_sa_defrag_extent *old; + struct new_sa_defrag_extent *new; + int ret; + + new = kmalloc(sizeof(*new), GFP_NOFS); + if (!new) + return NULL; + + new->inode = inode; + new->file_pos = ordered->file_offset; + new->len = ordered->len; + new->bytenr = ordered->start; + new->disk_len = ordered->disk_len; + new->compress_type = ordered->compress_type; + new->root = RB_ROOT; + INIT_LIST_HEAD(&new->head); + + path = btrfs_alloc_path(); + if (!path) + goto out_kfree; + + key.objectid = btrfs_ino(inode); + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = new->file_pos; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out_free_path; + if (ret > 0 && path->slots[0] > 0) + path->slots[0]--; + + /* find out all the old extents for the file range */ + while (1) { + struct btrfs_file_extent_item *extent; + struct extent_buffer *l; + int slot; + u64 num_bytes; + u64 offset; + u64 end; + u64 disk_bytenr; + u64 extent_offset; + + l = path->nodes[0]; + slot = path->slots[0]; + + if (slot >= btrfs_header_nritems(l)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out_free_path; + else if (ret > 0) + break; + continue; + } + + btrfs_item_key_to_cpu(l, &key, slot); + + if (key.objectid != btrfs_ino(inode)) + break; + if (key.type != BTRFS_EXTENT_DATA_KEY) + break; + if (key.offset >= new->file_pos + new->len) + break; + + extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item); + + num_bytes = btrfs_file_extent_num_bytes(l, extent); + if (key.offset + num_bytes < new->file_pos) + goto next; + + disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent); + if (!disk_bytenr) + goto next; + + extent_offset = btrfs_file_extent_offset(l, extent); + + old = kmalloc(sizeof(*old), GFP_NOFS); + if (!old) + goto out_free_path; + + offset = max(new->file_pos, key.offset); + end = min(new->file_pos + new->len, key.offset + num_bytes); + + old->bytenr = disk_bytenr; + old->extent_offset = extent_offset; + old->offset = offset - key.offset; + old->len = end - offset; + old->new = new; + old->count = 0; + list_add_tail(&old->list, &new->head); +next: + path->slots[0]++; + cond_resched(); + } + + btrfs_free_path(path); + atomic_inc(&root->fs_info->defrag_running); + + return new; + +out_free_path: + btrfs_free_path(path); +out_kfree: + free_sa_defrag_extent(new); + return NULL; +} + +static void btrfs_release_delalloc_bytes(struct btrfs_root *root, + u64 start, u64 len) +{ + struct btrfs_block_group_cache *cache; + + cache = btrfs_lookup_block_group(root->fs_info, start); + ASSERT(cache); + + spin_lock(&cache->lock); + cache->delalloc_bytes -= len; + spin_unlock(&cache->lock); + + btrfs_put_block_group(cache); +} + +/* as ordered data IO finishes, this gets called so we can finish + * an ordered extent if the range of bytes in the file it covers are + * fully written. + */ +static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) +{ + struct inode *inode = ordered_extent->inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans = NULL; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct extent_state *cached_state = NULL; + struct new_sa_defrag_extent *new = NULL; + int compress_type = 0; + int ret = 0; + u64 logical_len = ordered_extent->len; + bool nolock; + bool truncated = false; + + nolock = btrfs_is_free_space_inode(inode); + + if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) { + ret = -EIO; + goto out; + } + + btrfs_free_io_failure_record(inode, ordered_extent->file_offset, + ordered_extent->file_offset + + ordered_extent->len - 1); + + if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) { + truncated = true; + logical_len = ordered_extent->truncated_len; + /* Truncated the entire extent, don't bother adding */ + if (!logical_len) + goto out; + } + + if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { + BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */ + btrfs_ordered_update_i_size(inode, 0, ordered_extent); + if (nolock) + trans = btrfs_join_transaction_nolock(root); + else + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + trans = NULL; + goto out; + } + trans->block_rsv = &root->fs_info->delalloc_block_rsv; + ret = btrfs_update_inode_fallback(trans, root, inode); + if (ret) /* -ENOMEM or corruption */ + btrfs_abort_transaction(trans, root, ret); + goto out; + } + + lock_extent_bits(io_tree, ordered_extent->file_offset, + ordered_extent->file_offset + ordered_extent->len - 1, + 0, &cached_state); + + ret = test_range_bit(io_tree, ordered_extent->file_offset, + ordered_extent->file_offset + ordered_extent->len - 1, + EXTENT_DEFRAG, 1, cached_state); + if (ret) { + u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item); + if (0 && last_snapshot >= BTRFS_I(inode)->generation) + /* the inode is shared */ + new = record_old_file_extents(inode, ordered_extent); + + clear_extent_bit(io_tree, ordered_extent->file_offset, + ordered_extent->file_offset + ordered_extent->len - 1, + EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS); + } + + if (nolock) + trans = btrfs_join_transaction_nolock(root); + else + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + trans = NULL; + goto out_unlock; + } + + trans->block_rsv = &root->fs_info->delalloc_block_rsv; + + if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) + compress_type = ordered_extent->compress_type; + if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { + BUG_ON(compress_type); + ret = btrfs_mark_extent_written(trans, inode, + ordered_extent->file_offset, + ordered_extent->file_offset + + logical_len); + } else { + BUG_ON(root == root->fs_info->tree_root); + ret = insert_reserved_file_extent(trans, inode, + ordered_extent->file_offset, + ordered_extent->start, + ordered_extent->disk_len, + logical_len, logical_len, + compress_type, 0, 0, + BTRFS_FILE_EXTENT_REG); + if (!ret) + btrfs_release_delalloc_bytes(root, + ordered_extent->start, + ordered_extent->disk_len); + } + unpin_extent_cache(&BTRFS_I(inode)->extent_tree, + ordered_extent->file_offset, ordered_extent->len, + trans->transid); + if (ret < 0) { + btrfs_abort_transaction(trans, root, ret); + goto out_unlock; + } + + add_pending_csums(trans, inode, ordered_extent->file_offset, + &ordered_extent->list); + + btrfs_ordered_update_i_size(inode, 0, ordered_extent); + ret = btrfs_update_inode_fallback(trans, root, inode); + if (ret) { /* -ENOMEM or corruption */ + btrfs_abort_transaction(trans, root, ret); + goto out_unlock; + } + ret = 0; +out_unlock: + unlock_extent_cached(io_tree, ordered_extent->file_offset, + ordered_extent->file_offset + + ordered_extent->len - 1, &cached_state, GFP_NOFS); +out: + if (root != root->fs_info->tree_root) + btrfs_delalloc_release_metadata(inode, ordered_extent->len); + if (trans) + btrfs_end_transaction(trans, root); + + if (ret || truncated) { + u64 start, end; + + if (truncated) + start = ordered_extent->file_offset + logical_len; + else + start = ordered_extent->file_offset; + end = ordered_extent->file_offset + ordered_extent->len - 1; + clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS); + + /* Drop the cache for the part of the extent we didn't write. */ + btrfs_drop_extent_cache(inode, start, end, 0); + + /* + * If the ordered extent had an IOERR or something else went + * wrong we need to return the space for this ordered extent + * back to the allocator. We only free the extent in the + * truncated case if we didn't write out the extent at all. + */ + if ((ret || !logical_len) && + !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) && + !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) + btrfs_free_reserved_extent(root, ordered_extent->start, + ordered_extent->disk_len, 1); + } + + + /* + * This needs to be done to make sure anybody waiting knows we are done + * updating everything for this ordered extent. + */ + btrfs_remove_ordered_extent(inode, ordered_extent); + + /* for snapshot-aware defrag */ + if (new) { + if (ret) { + free_sa_defrag_extent(new); + atomic_dec(&root->fs_info->defrag_running); + } else { + relink_file_extents(new); + } + } + + /* once for us */ + btrfs_put_ordered_extent(ordered_extent); + /* once for the tree */ + btrfs_put_ordered_extent(ordered_extent); + + return ret; +} + +static void finish_ordered_fn(struct btrfs_work *work) +{ + struct btrfs_ordered_extent *ordered_extent; + ordered_extent = container_of(work, struct btrfs_ordered_extent, work); + btrfs_finish_ordered_io(ordered_extent); +} + +static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end, + struct extent_state *state, int uptodate) +{ + struct inode *inode = page->mapping->host; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_ordered_extent *ordered_extent = NULL; + struct btrfs_workqueue *wq; + btrfs_work_func_t func; + + trace_btrfs_writepage_end_io_hook(page, start, end, uptodate); + + ClearPagePrivate2(page); + if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start, + end - start + 1, uptodate)) + return 0; + + if (btrfs_is_free_space_inode(inode)) { + wq = root->fs_info->endio_freespace_worker; + func = btrfs_freespace_write_helper; + } else { + wq = root->fs_info->endio_write_workers; + func = btrfs_endio_write_helper; + } + + btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL, + NULL); + btrfs_queue_work(wq, &ordered_extent->work); + + return 0; +} + +static int __readpage_endio_check(struct inode *inode, + struct btrfs_io_bio *io_bio, + int icsum, struct page *page, + int pgoff, u64 start, size_t len) +{ + char *kaddr; + u32 csum_expected; + u32 csum = ~(u32)0; + static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + + csum_expected = *(((u32 *)io_bio->csum) + icsum); + + kaddr = kmap_atomic(page); + csum = btrfs_csum_data(kaddr + pgoff, csum, len); + btrfs_csum_final(csum, (char *)&csum); + if (csum != csum_expected) + goto zeroit; + + kunmap_atomic(kaddr); + return 0; +zeroit: + if (__ratelimit(&_rs)) + btrfs_warn(BTRFS_I(inode)->root->fs_info, + "csum failed ino %llu off %llu csum %u expected csum %u", + btrfs_ino(inode), start, csum, csum_expected); + memset(kaddr + pgoff, 1, len); + flush_dcache_page(page); + kunmap_atomic(kaddr); + if (csum_expected == 0) + return 0; + return -EIO; +} + +/* + * when reads are done, we need to check csums to verify the data is correct + * if there's a match, we allow the bio to finish. If not, the code in + * extent_io.c will try to find good copies for us. + */ +static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio, + u64 phy_offset, struct page *page, + u64 start, u64 end, int mirror) +{ + size_t offset = start - page_offset(page); + struct inode *inode = page->mapping->host; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_root *root = BTRFS_I(inode)->root; + + if (PageChecked(page)) { + ClearPageChecked(page); + return 0; + } + + if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) + return 0; + + if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID && + test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) { + clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM, + GFP_NOFS); + return 0; + } + + phy_offset >>= inode->i_sb->s_blocksize_bits; + return __readpage_endio_check(inode, io_bio, phy_offset, page, offset, + start, (size_t)(end - start + 1)); +} + +struct delayed_iput { + struct list_head list; + struct inode *inode; +}; + +/* JDM: If this is fs-wide, why can't we add a pointer to + * btrfs_inode instead and avoid the allocation? */ +void btrfs_add_delayed_iput(struct inode *inode) +{ + struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; + struct delayed_iput *delayed; + + if (atomic_add_unless(&inode->i_count, -1, 1)) + return; + + delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL); + delayed->inode = inode; + + spin_lock(&fs_info->delayed_iput_lock); + list_add_tail(&delayed->list, &fs_info->delayed_iputs); + spin_unlock(&fs_info->delayed_iput_lock); +} + +void btrfs_run_delayed_iputs(struct btrfs_root *root) +{ + LIST_HEAD(list); + struct btrfs_fs_info *fs_info = root->fs_info; + struct delayed_iput *delayed; + int empty; + + spin_lock(&fs_info->delayed_iput_lock); + empty = list_empty(&fs_info->delayed_iputs); + spin_unlock(&fs_info->delayed_iput_lock); + if (empty) + return; + + down_read(&fs_info->delayed_iput_sem); + + spin_lock(&fs_info->delayed_iput_lock); + list_splice_init(&fs_info->delayed_iputs, &list); + spin_unlock(&fs_info->delayed_iput_lock); + + while (!list_empty(&list)) { + delayed = list_entry(list.next, struct delayed_iput, list); + list_del(&delayed->list); + iput(delayed->inode); + kfree(delayed); + } + + up_read(&root->fs_info->delayed_iput_sem); +} + +/* + * This is called in transaction commit time. If there are no orphan + * files in the subvolume, it removes orphan item and frees block_rsv + * structure. + */ +void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_block_rsv *block_rsv; + int ret; + + if (atomic_read(&root->orphan_inodes) || + root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) + return; + + spin_lock(&root->orphan_lock); + if (atomic_read(&root->orphan_inodes)) { + spin_unlock(&root->orphan_lock); + return; + } + + if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) { + spin_unlock(&root->orphan_lock); + return; + } + + block_rsv = root->orphan_block_rsv; + root->orphan_block_rsv = NULL; + spin_unlock(&root->orphan_lock); + + if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) && + btrfs_root_refs(&root->root_item) > 0) { + ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root, + root->root_key.objectid); + if (ret) + btrfs_abort_transaction(trans, root, ret); + else + clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, + &root->state); + } + + if (block_rsv) { + WARN_ON(block_rsv->size > 0); + btrfs_free_block_rsv(root, block_rsv); + } +} + +/* + * This creates an orphan entry for the given inode in case something goes + * wrong in the middle of an unlink/truncate. + * + * NOTE: caller of this function should reserve 5 units of metadata for + * this function. + */ +int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_block_rsv *block_rsv = NULL; + int reserve = 0; + int insert = 0; + int ret; + + if (!root->orphan_block_rsv) { + block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); + if (!block_rsv) + return -ENOMEM; + } + + spin_lock(&root->orphan_lock); + if (!root->orphan_block_rsv) { + root->orphan_block_rsv = block_rsv; + } else if (block_rsv) { + btrfs_free_block_rsv(root, block_rsv); + block_rsv = NULL; + } + + if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, + &BTRFS_I(inode)->runtime_flags)) { +#if 0 + /* + * For proper ENOSPC handling, we should do orphan + * cleanup when mounting. But this introduces backward + * compatibility issue. + */ + if (!xchg(&root->orphan_item_inserted, 1)) + insert = 2; + else + insert = 1; +#endif + insert = 1; + atomic_inc(&root->orphan_inodes); + } + + if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED, + &BTRFS_I(inode)->runtime_flags)) + reserve = 1; + spin_unlock(&root->orphan_lock); + + /* grab metadata reservation from transaction handle */ + if (reserve) { + ret = btrfs_orphan_reserve_metadata(trans, inode); + BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */ + } + + /* insert an orphan item to track this unlinked/truncated file */ + if (insert >= 1) { + ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode)); + if (ret) { + atomic_dec(&root->orphan_inodes); + if (reserve) { + clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, + &BTRFS_I(inode)->runtime_flags); + btrfs_orphan_release_metadata(inode); + } + if (ret != -EEXIST) { + clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, + &BTRFS_I(inode)->runtime_flags); + btrfs_abort_transaction(trans, root, ret); + return ret; + } + } + ret = 0; + } + + /* insert an orphan item to track subvolume contains orphan files */ + if (insert >= 2) { + ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root, + root->root_key.objectid); + if (ret && ret != -EEXIST) { + btrfs_abort_transaction(trans, root, ret); + return ret; + } + } + return 0; +} + +/* + * We have done the truncate/delete so we can go ahead and remove the orphan + * item for this particular inode. + */ +static int btrfs_orphan_del(struct btrfs_trans_handle *trans, + struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + int delete_item = 0; + int release_rsv = 0; + int ret = 0; + + spin_lock(&root->orphan_lock); + if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, + &BTRFS_I(inode)->runtime_flags)) + delete_item = 1; + + if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, + &BTRFS_I(inode)->runtime_flags)) + release_rsv = 1; + spin_unlock(&root->orphan_lock); + + if (delete_item) { + atomic_dec(&root->orphan_inodes); + if (trans) + ret = btrfs_del_orphan_item(trans, root, + btrfs_ino(inode)); + } + + if (release_rsv) + btrfs_orphan_release_metadata(inode); + + return ret; +} + +/* + * this cleans up any orphans that may be left on the list from the last use + * of this root. + */ +int btrfs_orphan_cleanup(struct btrfs_root *root) +{ + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_key key, found_key; + struct btrfs_trans_handle *trans; + struct inode *inode; + u64 last_objectid = 0; + int ret = 0, nr_unlink = 0, nr_truncate = 0; + + if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED)) + return 0; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + path->reada = -1; + + key.objectid = BTRFS_ORPHAN_OBJECTID; + key.type = BTRFS_ORPHAN_ITEM_KEY; + key.offset = (u64)-1; + + while (1) { + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + /* + * if ret == 0 means we found what we were searching for, which + * is weird, but possible, so only screw with path if we didn't + * find the key and see if we have stuff that matches + */ + if (ret > 0) { + ret = 0; + if (path->slots[0] == 0) + break; + path->slots[0]--; + } + + /* pull out the item */ + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + /* make sure the item matches what we want */ + if (found_key.objectid != BTRFS_ORPHAN_OBJECTID) + break; + if (found_key.type != BTRFS_ORPHAN_ITEM_KEY) + break; + + /* release the path since we're done with it */ + btrfs_release_path(path); + + /* + * this is where we are basically btrfs_lookup, without the + * crossing root thing. we store the inode number in the + * offset of the orphan item. + */ + + if (found_key.offset == last_objectid) { + btrfs_err(root->fs_info, + "Error removing orphan entry, stopping orphan cleanup"); + ret = -EINVAL; + goto out; + } + + last_objectid = found_key.offset; + + found_key.objectid = found_key.offset; + found_key.type = BTRFS_INODE_ITEM_KEY; + found_key.offset = 0; + inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL); + ret = PTR_ERR_OR_ZERO(inode); + if (ret && ret != -ESTALE) + goto out; + + if (ret == -ESTALE && root == root->fs_info->tree_root) { + struct btrfs_root *dead_root; + struct btrfs_fs_info *fs_info = root->fs_info; + int is_dead_root = 0; + + /* + * this is an orphan in the tree root. Currently these + * could come from 2 sources: + * a) a snapshot deletion in progress + * b) a free space cache inode + * We need to distinguish those two, as the snapshot + * orphan must not get deleted. + * find_dead_roots already ran before us, so if this + * is a snapshot deletion, we should find the root + * in the dead_roots list + */ + spin_lock(&fs_info->trans_lock); + list_for_each_entry(dead_root, &fs_info->dead_roots, + root_list) { + if (dead_root->root_key.objectid == + found_key.objectid) { + is_dead_root = 1; + break; + } + } + spin_unlock(&fs_info->trans_lock); + if (is_dead_root) { + /* prevent this orphan from being found again */ + key.offset = found_key.objectid - 1; + continue; + } + } + /* + * Inode is already gone but the orphan item is still there, + * kill the orphan item. + */ + if (ret == -ESTALE) { + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out; + } + btrfs_debug(root->fs_info, "auto deleting %Lu", + found_key.objectid); + ret = btrfs_del_orphan_item(trans, root, + found_key.objectid); + btrfs_end_transaction(trans, root); + if (ret) + goto out; + continue; + } + + /* + * add this inode to the orphan list so btrfs_orphan_del does + * the proper thing when we hit it + */ + set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, + &BTRFS_I(inode)->runtime_flags); + atomic_inc(&root->orphan_inodes); + + /* if we have links, this was a truncate, lets do that */ + if (inode->i_nlink) { + if (WARN_ON(!S_ISREG(inode->i_mode))) { + iput(inode); + continue; + } + nr_truncate++; + + /* 1 for the orphan item deletion. */ + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + iput(inode); + ret = PTR_ERR(trans); + goto out; + } + ret = btrfs_orphan_add(trans, inode); + btrfs_end_transaction(trans, root); + if (ret) { + iput(inode); + goto out; + } + + ret = btrfs_truncate(inode); + if (ret) + btrfs_orphan_del(NULL, inode); + } else { + nr_unlink++; + } + + /* this will do delete_inode and everything for us */ + iput(inode); + if (ret) + goto out; + } + /* release the path since we're done with it */ + btrfs_release_path(path); + + root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE; + + if (root->orphan_block_rsv) + btrfs_block_rsv_release(root, root->orphan_block_rsv, + (u64)-1); + + if (root->orphan_block_rsv || + test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) { + trans = btrfs_join_transaction(root); + if (!IS_ERR(trans)) + btrfs_end_transaction(trans, root); + } + + if (nr_unlink) + btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink); + if (nr_truncate) + btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate); + +out: + if (ret) + btrfs_err(root->fs_info, + "could not do orphan cleanup %d", ret); + btrfs_free_path(path); + return ret; +} + +/* + * very simple check to peek ahead in the leaf looking for xattrs. If we + * don't find any xattrs, we know there can't be any acls. + * + * slot is the slot the inode is in, objectid is the objectid of the inode + */ +static noinline int acls_after_inode_item(struct extent_buffer *leaf, + int slot, u64 objectid, + int *first_xattr_slot) +{ + u32 nritems = btrfs_header_nritems(leaf); + struct btrfs_key found_key; + static u64 xattr_access = 0; + static u64 xattr_default = 0; + int scanned = 0; + + if (!xattr_access) { + xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS, + strlen(POSIX_ACL_XATTR_ACCESS)); + xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT, + strlen(POSIX_ACL_XATTR_DEFAULT)); + } + + slot++; + *first_xattr_slot = -1; + while (slot < nritems) { + btrfs_item_key_to_cpu(leaf, &found_key, slot); + + /* we found a different objectid, there must not be acls */ + if (found_key.objectid != objectid) + return 0; + + /* we found an xattr, assume we've got an acl */ + if (found_key.type == BTRFS_XATTR_ITEM_KEY) { + if (*first_xattr_slot == -1) + *first_xattr_slot = slot; + if (found_key.offset == xattr_access || + found_key.offset == xattr_default) + return 1; + } + + /* + * we found a key greater than an xattr key, there can't + * be any acls later on + */ + if (found_key.type > BTRFS_XATTR_ITEM_KEY) + return 0; + + slot++; + scanned++; + + /* + * it goes inode, inode backrefs, xattrs, extents, + * so if there are a ton of hard links to an inode there can + * be a lot of backrefs. Don't waste time searching too hard, + * this is just an optimization + */ + if (scanned >= 8) + break; + } + /* we hit the end of the leaf before we found an xattr or + * something larger than an xattr. We have to assume the inode + * has acls + */ + if (*first_xattr_slot == -1) + *first_xattr_slot = slot; + return 1; +} + +/* + * read an inode from the btree into the in-memory inode + */ +static void btrfs_read_locked_inode(struct inode *inode) +{ + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_inode_item *inode_item; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_key location; + unsigned long ptr; + int maybe_acls; + u32 rdev; + int ret; + bool filled = false; + int first_xattr_slot; + + ret = btrfs_fill_inode(inode, &rdev); + if (!ret) + filled = true; + + path = btrfs_alloc_path(); + if (!path) + goto make_bad; + + memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); + + ret = btrfs_lookup_inode(NULL, root, path, &location, 0); + if (ret) + goto make_bad; + + leaf = path->nodes[0]; + + if (filled) + goto cache_index; + + inode_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_inode_item); + inode->i_mode = btrfs_inode_mode(leaf, inode_item); + set_nlink(inode, btrfs_inode_nlink(leaf, inode_item)); + i_uid_write(inode, btrfs_inode_uid(leaf, inode_item)); + i_gid_write(inode, btrfs_inode_gid(leaf, inode_item)); + btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item)); + + inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime); + inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime); + + inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime); + inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime); + + inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime); + inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime); + + BTRFS_I(inode)->i_otime.tv_sec = + btrfs_timespec_sec(leaf, &inode_item->otime); + BTRFS_I(inode)->i_otime.tv_nsec = + btrfs_timespec_nsec(leaf, &inode_item->otime); + + inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item)); + BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item); + BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item); + + inode->i_version = btrfs_inode_sequence(leaf, inode_item); + inode->i_generation = BTRFS_I(inode)->generation; + inode->i_rdev = 0; + rdev = btrfs_inode_rdev(leaf, inode_item); + + BTRFS_I(inode)->index_cnt = (u64)-1; + BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); + +cache_index: + /* + * If we were modified in the current generation and evicted from memory + * and then re-read we need to do a full sync since we don't have any + * idea about which extents were modified before we were evicted from + * cache. + * + * This is required for both inode re-read from disk and delayed inode + * in delayed_nodes_tree. + */ + if (BTRFS_I(inode)->last_trans == root->fs_info->generation) + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &BTRFS_I(inode)->runtime_flags); + + path->slots[0]++; + if (inode->i_nlink != 1 || + path->slots[0] >= btrfs_header_nritems(leaf)) + goto cache_acl; + + btrfs_item_key_to_cpu(leaf, &location, path->slots[0]); + if (location.objectid != btrfs_ino(inode)) + goto cache_acl; + + ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); + if (location.type == BTRFS_INODE_REF_KEY) { + struct btrfs_inode_ref *ref; + + ref = (struct btrfs_inode_ref *)ptr; + BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref); + } else if (location.type == BTRFS_INODE_EXTREF_KEY) { + struct btrfs_inode_extref *extref; + + extref = (struct btrfs_inode_extref *)ptr; + BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf, + extref); + } +cache_acl: + /* + * try to precache a NULL acl entry for files that don't have + * any xattrs or acls + */ + maybe_acls = acls_after_inode_item(leaf, path->slots[0], + btrfs_ino(inode), &first_xattr_slot); + if (first_xattr_slot != -1) { + path->slots[0] = first_xattr_slot; + ret = btrfs_load_inode_props(inode, path); + if (ret) + btrfs_err(root->fs_info, + "error loading props for ino %llu (root %llu): %d", + btrfs_ino(inode), + root->root_key.objectid, ret); + } + btrfs_free_path(path); + + if (!maybe_acls) + cache_no_acl(inode); + + switch (inode->i_mode & S_IFMT) { + case S_IFREG: + inode->i_mapping->a_ops = &btrfs_aops; + BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; + break; + case S_IFDIR: + inode->i_fop = &btrfs_dir_file_operations; + if (root == root->fs_info->tree_root) + inode->i_op = &btrfs_dir_ro_inode_operations; + else + inode->i_op = &btrfs_dir_inode_operations; + break; + case S_IFLNK: + inode->i_op = &btrfs_symlink_inode_operations; + inode->i_mapping->a_ops = &btrfs_symlink_aops; + break; + default: + inode->i_op = &btrfs_special_inode_operations; + init_special_inode(inode, inode->i_mode, rdev); + break; + } + + btrfs_update_iflags(inode); + return; + +make_bad: + btrfs_free_path(path); + make_bad_inode(inode); +} + +/* + * given a leaf and an inode, copy the inode fields into the leaf + */ +static void fill_inode_item(struct btrfs_trans_handle *trans, + struct extent_buffer *leaf, + struct btrfs_inode_item *item, + struct inode *inode) +{ + struct btrfs_map_token token; + + btrfs_init_map_token(&token); + + btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token); + btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token); + btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size, + &token); + btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token); + btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token); + + btrfs_set_token_timespec_sec(leaf, &item->atime, + inode->i_atime.tv_sec, &token); + btrfs_set_token_timespec_nsec(leaf, &item->atime, + inode->i_atime.tv_nsec, &token); + + btrfs_set_token_timespec_sec(leaf, &item->mtime, + inode->i_mtime.tv_sec, &token); + btrfs_set_token_timespec_nsec(leaf, &item->mtime, + inode->i_mtime.tv_nsec, &token); + + btrfs_set_token_timespec_sec(leaf, &item->ctime, + inode->i_ctime.tv_sec, &token); + btrfs_set_token_timespec_nsec(leaf, &item->ctime, + inode->i_ctime.tv_nsec, &token); + + btrfs_set_token_timespec_sec(leaf, &item->otime, + BTRFS_I(inode)->i_otime.tv_sec, &token); + btrfs_set_token_timespec_nsec(leaf, &item->otime, + BTRFS_I(inode)->i_otime.tv_nsec, &token); + + btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode), + &token); + btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation, + &token); + btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token); + btrfs_set_token_inode_transid(leaf, item, trans->transid, &token); + btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token); + btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token); + btrfs_set_token_inode_block_group(leaf, item, 0, &token); +} + +/* + * copy everything in the in-memory inode into the btree. + */ +static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct inode *inode) +{ + struct btrfs_inode_item *inode_item; + struct btrfs_path *path; + struct extent_buffer *leaf; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->leave_spinning = 1; + ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location, + 1); + if (ret) { + if (ret > 0) + ret = -ENOENT; + goto failed; + } + + leaf = path->nodes[0]; + inode_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_inode_item); + + fill_inode_item(trans, leaf, inode_item, inode); + btrfs_mark_buffer_dirty(leaf); + btrfs_set_inode_last_trans(trans, inode); + ret = 0; +failed: + btrfs_free_path(path); + return ret; +} + +/* + * copy everything in the in-memory inode into the btree. + */ +noinline int btrfs_update_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct inode *inode) +{ + int ret; + + /* + * If the inode is a free space inode, we can deadlock during commit + * if we put it into the delayed code. + * + * The data relocation inode should also be directly updated + * without delay + */ + if (!btrfs_is_free_space_inode(inode) + && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID + && !root->fs_info->log_root_recovering) { + btrfs_update_root_times(trans, root); + + ret = btrfs_delayed_update_inode(trans, root, inode); + if (!ret) + btrfs_set_inode_last_trans(trans, inode); + return ret; + } + + return btrfs_update_inode_item(trans, root, inode); +} + +noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *inode) +{ + int ret; + + ret = btrfs_update_inode(trans, root, inode); + if (ret == -ENOSPC) + return btrfs_update_inode_item(trans, root, inode); + return ret; +} + +/* + * unlink helper that gets used here in inode.c and in the tree logging + * recovery code. It remove a link in a directory with a given name, and + * also drops the back refs in the inode to the directory + */ +static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *dir, struct inode *inode, + const char *name, int name_len) +{ + struct btrfs_path *path; + int ret = 0; + struct extent_buffer *leaf; + struct btrfs_dir_item *di; + struct btrfs_key key; + u64 index; + u64 ino = btrfs_ino(inode); + u64 dir_ino = btrfs_ino(dir); + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + path->leave_spinning = 1; + di = btrfs_lookup_dir_item(trans, root, path, dir_ino, + name, name_len, -1); + if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto err; + } + if (!di) { + ret = -ENOENT; + goto err; + } + leaf = path->nodes[0]; + btrfs_dir_item_key_to_cpu(leaf, di, &key); + ret = btrfs_delete_one_dir_name(trans, root, path, di); + if (ret) + goto err; + btrfs_release_path(path); + + /* + * If we don't have dir index, we have to get it by looking up + * the inode ref, since we get the inode ref, remove it directly, + * it is unnecessary to do delayed deletion. + * + * But if we have dir index, needn't search inode ref to get it. + * Since the inode ref is close to the inode item, it is better + * that we delay to delete it, and just do this deletion when + * we update the inode item. + */ + if (BTRFS_I(inode)->dir_index) { + ret = btrfs_delayed_delete_inode_ref(inode); + if (!ret) { + index = BTRFS_I(inode)->dir_index; + goto skip_backref; + } + } + + ret = btrfs_del_inode_ref(trans, root, name, name_len, ino, + dir_ino, &index); + if (ret) { + btrfs_info(root->fs_info, + "failed to delete reference to %.*s, inode %llu parent %llu", + name_len, name, ino, dir_ino); + btrfs_abort_transaction(trans, root, ret); + goto err; + } +skip_backref: + ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto err; + } + + ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, + inode, dir_ino); + if (ret != 0 && ret != -ENOENT) { + btrfs_abort_transaction(trans, root, ret); + goto err; + } + + ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, + dir, index); + if (ret == -ENOENT) + ret = 0; + else if (ret) + btrfs_abort_transaction(trans, root, ret); +err: + btrfs_free_path(path); + if (ret) + goto out; + + btrfs_i_size_write(dir, dir->i_size - name_len * 2); + inode_inc_iversion(inode); + inode_inc_iversion(dir); + inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME; + ret = btrfs_update_inode(trans, root, dir); +out: + return ret; +} + +int btrfs_unlink_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *dir, struct inode *inode, + const char *name, int name_len) +{ + int ret; + ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len); + if (!ret) { + drop_nlink(inode); + ret = btrfs_update_inode(trans, root, inode); + } + return ret; +} + +/* + * helper to start transaction for unlink and rmdir. + * + * unlink and rmdir are special in btrfs, they do not always free space, so + * if we cannot make our reservations the normal way try and see if there is + * plenty of slack room in the global reserve to migrate, otherwise we cannot + * allow the unlink to occur. + */ +static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + int ret; + + /* + * 1 for the possible orphan item + * 1 for the dir item + * 1 for the dir index + * 1 for the inode ref + * 1 for the inode + */ + trans = btrfs_start_transaction(root, 5); + if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC) + return trans; + + if (PTR_ERR(trans) == -ENOSPC) { + u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5); + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) + return trans; + ret = btrfs_cond_migrate_bytes(root->fs_info, + &root->fs_info->trans_block_rsv, + num_bytes, 5); + if (ret) { + btrfs_end_transaction(trans, root); + return ERR_PTR(ret); + } + trans->block_rsv = &root->fs_info->trans_block_rsv; + trans->bytes_reserved = num_bytes; + } + return trans; +} + +static int btrfs_unlink(struct inode *dir, struct dentry *dentry) +{ + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_trans_handle *trans; + struct inode *inode = d_inode(dentry); + int ret; + + trans = __unlink_start_trans(dir); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0); + + ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry), + dentry->d_name.name, dentry->d_name.len); + if (ret) + goto out; + + if (inode->i_nlink == 0) { + ret = btrfs_orphan_add(trans, inode); + if (ret) + goto out; + } + +out: + btrfs_end_transaction(trans, root); + btrfs_btree_balance_dirty(root); + return ret; +} + +int btrfs_unlink_subvol(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *dir, u64 objectid, + const char *name, int name_len) +{ + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_dir_item *di; + struct btrfs_key key; + u64 index; + int ret; + u64 dir_ino = btrfs_ino(dir); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + di = btrfs_lookup_dir_item(trans, root, path, dir_ino, + name, name_len, -1); + if (IS_ERR_OR_NULL(di)) { + if (!di) + ret = -ENOENT; + else + ret = PTR_ERR(di); + goto out; + } + + leaf = path->nodes[0]; + btrfs_dir_item_key_to_cpu(leaf, di, &key); + WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid); + ret = btrfs_delete_one_dir_name(trans, root, path, di); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out; + } + btrfs_release_path(path); + + ret = btrfs_del_root_ref(trans, root->fs_info->tree_root, + objectid, root->root_key.objectid, + dir_ino, &index, name, name_len); + if (ret < 0) { + if (ret != -ENOENT) { + btrfs_abort_transaction(trans, root, ret); + goto out; + } + di = btrfs_search_dir_index_item(root, path, dir_ino, + name, name_len); + if (IS_ERR_OR_NULL(di)) { + if (!di) + ret = -ENOENT; + else + ret = PTR_ERR(di); + btrfs_abort_transaction(trans, root, ret); + goto out; + } + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + btrfs_release_path(path); + index = key.offset; + } + btrfs_release_path(path); + + ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out; + } + + btrfs_i_size_write(dir, dir->i_size - name_len * 2); + inode_inc_iversion(dir); + dir->i_mtime = dir->i_ctime = CURRENT_TIME; + ret = btrfs_update_inode_fallback(trans, root, dir); + if (ret) + btrfs_abort_transaction(trans, root, ret); +out: + btrfs_free_path(path); + return ret; +} + +static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) +{ + struct inode *inode = d_inode(dentry); + int err = 0; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_trans_handle *trans; + + if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) + return -ENOTEMPTY; + if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) + return -EPERM; + + trans = __unlink_start_trans(dir); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { + err = btrfs_unlink_subvol(trans, root, dir, + BTRFS_I(inode)->location.objectid, + dentry->d_name.name, + dentry->d_name.len); + goto out; + } + + err = btrfs_orphan_add(trans, inode); + if (err) + goto out; + + /* now the directory is empty */ + err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry), + dentry->d_name.name, dentry->d_name.len); + if (!err) + btrfs_i_size_write(inode, 0); +out: + btrfs_end_transaction(trans, root); + btrfs_btree_balance_dirty(root); + + return err; +} + +static int truncate_space_check(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytes_deleted) +{ + int ret; + + bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted); + ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv, + bytes_deleted, BTRFS_RESERVE_NO_FLUSH); + if (!ret) + trans->bytes_reserved += bytes_deleted; + return ret; + +} + +/* + * this can truncate away extent items, csum items and directory items. + * It starts at a high offset and removes keys until it can't find + * any higher than new_size + * + * csum items that cross the new i_size are truncated to the new size + * as well. + * + * min_type is the minimum key type to truncate down to. If set to 0, this + * will kill all the items on this inode, including the INODE_ITEM_KEY. + */ +int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *inode, + u64 new_size, u32 min_type) +{ + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_file_extent_item *fi; + struct btrfs_key key; + struct btrfs_key found_key; + u64 extent_start = 0; + u64 extent_num_bytes = 0; + u64 extent_offset = 0; + u64 item_end = 0; + u64 last_size = (u64)-1; + u32 found_type = (u8)-1; + int found_extent; + int del_item; + int pending_del_nr = 0; + int pending_del_slot = 0; + int extent_type = -1; + int ret; + int err = 0; + u64 ino = btrfs_ino(inode); + u64 bytes_deleted = 0; + bool be_nice = 0; + bool should_throttle = 0; + bool should_end = 0; + + BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY); + + /* + * for non-free space inodes and ref cows, we want to back off from + * time to time + */ + if (!btrfs_is_free_space_inode(inode) && + test_bit(BTRFS_ROOT_REF_COWS, &root->state)) + be_nice = 1; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + path->reada = -1; + + /* + * We want to drop from the next block forward in case this new size is + * not block aligned since we will be keeping the last block of the + * extent just the way it is. + */ + if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) || + root == root->fs_info->tree_root) + btrfs_drop_extent_cache(inode, ALIGN(new_size, + root->sectorsize), (u64)-1, 0); + + /* + * This function is also used to drop the items in the log tree before + * we relog the inode, so if root != BTRFS_I(inode)->root, it means + * it is used to drop the loged items. So we shouldn't kill the delayed + * items. + */ + if (min_type == 0 && root == BTRFS_I(inode)->root) + btrfs_kill_delayed_inode_items(inode); + + key.objectid = ino; + key.offset = (u64)-1; + key.type = (u8)-1; + +search_again: + /* + * with a 16K leaf size and 128MB extents, you can actually queue + * up a huge file in a single leaf. Most of the time that + * bytes_deleted is > 0, it will be huge by the time we get here + */ + if (be_nice && bytes_deleted > 32 * 1024 * 1024) { + if (btrfs_should_end_transaction(trans, root)) { + err = -EAGAIN; + goto error; + } + } + + + path->leave_spinning = 1; + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) { + err = ret; + goto out; + } + + if (ret > 0) { + /* there are no items in the tree for us to truncate, we're + * done + */ + if (path->slots[0] == 0) + goto out; + path->slots[0]--; + } + + while (1) { + fi = NULL; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + found_type = found_key.type; + + if (found_key.objectid != ino) + break; + + if (found_type < min_type) + break; + + item_end = found_key.offset; + if (found_type == BTRFS_EXTENT_DATA_KEY) { + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + extent_type = btrfs_file_extent_type(leaf, fi); + if (extent_type != BTRFS_FILE_EXTENT_INLINE) { + item_end += + btrfs_file_extent_num_bytes(leaf, fi); + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + item_end += btrfs_file_extent_inline_len(leaf, + path->slots[0], fi); + } + item_end--; + } + if (found_type > min_type) { + del_item = 1; + } else { + if (item_end < new_size) + break; + if (found_key.offset >= new_size) + del_item = 1; + else + del_item = 0; + } + found_extent = 0; + /* FIXME, shrink the extent if the ref count is only 1 */ + if (found_type != BTRFS_EXTENT_DATA_KEY) + goto delete; + + if (del_item) + last_size = found_key.offset; + else + last_size = new_size; + + if (extent_type != BTRFS_FILE_EXTENT_INLINE) { + u64 num_dec; + extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); + if (!del_item) { + u64 orig_num_bytes = + btrfs_file_extent_num_bytes(leaf, fi); + extent_num_bytes = ALIGN(new_size - + found_key.offset, + root->sectorsize); + btrfs_set_file_extent_num_bytes(leaf, fi, + extent_num_bytes); + num_dec = (orig_num_bytes - + extent_num_bytes); + if (test_bit(BTRFS_ROOT_REF_COWS, + &root->state) && + extent_start != 0) + inode_sub_bytes(inode, num_dec); + btrfs_mark_buffer_dirty(leaf); + } else { + extent_num_bytes = + btrfs_file_extent_disk_num_bytes(leaf, + fi); + extent_offset = found_key.offset - + btrfs_file_extent_offset(leaf, fi); + + /* FIXME blocksize != 4096 */ + num_dec = btrfs_file_extent_num_bytes(leaf, fi); + if (extent_start != 0) { + found_extent = 1; + if (test_bit(BTRFS_ROOT_REF_COWS, + &root->state)) + inode_sub_bytes(inode, num_dec); + } + } + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + /* + * we can't truncate inline items that have had + * special encodings + */ + if (!del_item && + btrfs_file_extent_compression(leaf, fi) == 0 && + btrfs_file_extent_encryption(leaf, fi) == 0 && + btrfs_file_extent_other_encoding(leaf, fi) == 0) { + u32 size = new_size - found_key.offset; + + if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) + inode_sub_bytes(inode, item_end + 1 - + new_size); + + /* + * update the ram bytes to properly reflect + * the new size of our item + */ + btrfs_set_file_extent_ram_bytes(leaf, fi, size); + size = + btrfs_file_extent_calc_inline_size(size); + btrfs_truncate_item(root, path, size, 1); + } else if (test_bit(BTRFS_ROOT_REF_COWS, + &root->state)) { + inode_sub_bytes(inode, item_end + 1 - + found_key.offset); + } + } +delete: + if (del_item) { + if (!pending_del_nr) { + /* no pending yet, add ourselves */ + pending_del_slot = path->slots[0]; + pending_del_nr = 1; + } else if (pending_del_nr && + path->slots[0] + 1 == pending_del_slot) { + /* hop on the pending chunk */ + pending_del_nr++; + pending_del_slot = path->slots[0]; + } else { + BUG(); + } + } else { + break; + } + should_throttle = 0; + + if (found_extent && + (test_bit(BTRFS_ROOT_REF_COWS, &root->state) || + root == root->fs_info->tree_root)) { + btrfs_set_path_blocking(path); + bytes_deleted += extent_num_bytes; + ret = btrfs_free_extent(trans, root, extent_start, + extent_num_bytes, 0, + btrfs_header_owner(leaf), + ino, extent_offset, 0); + BUG_ON(ret); + if (btrfs_should_throttle_delayed_refs(trans, root)) + btrfs_async_run_delayed_refs(root, + trans->delayed_ref_updates * 2, 0); + if (be_nice) { + if (truncate_space_check(trans, root, + extent_num_bytes)) { + should_end = 1; + } + if (btrfs_should_throttle_delayed_refs(trans, + root)) { + should_throttle = 1; + } + } + } + + if (found_type == BTRFS_INODE_ITEM_KEY) + break; + + if (path->slots[0] == 0 || + path->slots[0] != pending_del_slot || + should_throttle || should_end) { + if (pending_del_nr) { + ret = btrfs_del_items(trans, root, path, + pending_del_slot, + pending_del_nr); + if (ret) { + btrfs_abort_transaction(trans, + root, ret); + goto error; + } + pending_del_nr = 0; + } + btrfs_release_path(path); + if (should_throttle) { + unsigned long updates = trans->delayed_ref_updates; + if (updates) { + trans->delayed_ref_updates = 0; + ret = btrfs_run_delayed_refs(trans, root, updates * 2); + if (ret && !err) + err = ret; + } + } + /* + * if we failed to refill our space rsv, bail out + * and let the transaction restart + */ + if (should_end) { + err = -EAGAIN; + goto error; + } + goto search_again; + } else { + path->slots[0]--; + } + } +out: + if (pending_del_nr) { + ret = btrfs_del_items(trans, root, path, pending_del_slot, + pending_del_nr); + if (ret) + btrfs_abort_transaction(trans, root, ret); + } +error: + if (last_size != (u64)-1 && + root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) + btrfs_ordered_update_i_size(inode, last_size, NULL); + + btrfs_free_path(path); + + if (be_nice && bytes_deleted > 32 * 1024 * 1024) { + unsigned long updates = trans->delayed_ref_updates; + if (updates) { + trans->delayed_ref_updates = 0; + ret = btrfs_run_delayed_refs(trans, root, updates * 2); + if (ret && !err) + err = ret; + } + } + return err; +} + +/* + * btrfs_truncate_page - read, zero a chunk and write a page + * @inode - inode that we're zeroing + * @from - the offset to start zeroing + * @len - the length to zero, 0 to zero the entire range respective to the + * offset + * @front - zero up to the offset instead of from the offset on + * + * This will find the page for the "from" offset and cow the page and zero the + * part we want to zero. This is used with truncate and hole punching. + */ +int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len, + int front) +{ + struct address_space *mapping = inode->i_mapping; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_ordered_extent *ordered; + struct extent_state *cached_state = NULL; + char *kaddr; + u32 blocksize = root->sectorsize; + pgoff_t index = from >> PAGE_CACHE_SHIFT; + unsigned offset = from & (PAGE_CACHE_SIZE-1); + struct page *page; + gfp_t mask = btrfs_alloc_write_mask(mapping); + int ret = 0; + u64 page_start; + u64 page_end; + + if ((offset & (blocksize - 1)) == 0 && + (!len || ((len & (blocksize - 1)) == 0))) + goto out; + ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); + if (ret) + goto out; + +again: + page = find_or_create_page(mapping, index, mask); + if (!page) { + btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); + ret = -ENOMEM; + goto out; + } + + page_start = page_offset(page); + page_end = page_start + PAGE_CACHE_SIZE - 1; + + if (!PageUptodate(page)) { + ret = btrfs_readpage(NULL, page); + lock_page(page); + if (page->mapping != mapping) { + unlock_page(page); + page_cache_release(page); + goto again; + } + if (!PageUptodate(page)) { + ret = -EIO; + goto out_unlock; + } + } + wait_on_page_writeback(page); + + lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state); + set_page_extent_mapped(page); + + ordered = btrfs_lookup_ordered_extent(inode, page_start); + if (ordered) { + unlock_extent_cached(io_tree, page_start, page_end, + &cached_state, GFP_NOFS); + unlock_page(page); + page_cache_release(page); + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + goto again; + } + + clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, + EXTENT_DIRTY | EXTENT_DELALLOC | + EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, + 0, 0, &cached_state, GFP_NOFS); + + ret = btrfs_set_extent_delalloc(inode, page_start, page_end, + &cached_state); + if (ret) { + unlock_extent_cached(io_tree, page_start, page_end, + &cached_state, GFP_NOFS); + goto out_unlock; + } + + if (offset != PAGE_CACHE_SIZE) { + if (!len) + len = PAGE_CACHE_SIZE - offset; + kaddr = kmap(page); + if (front) + memset(kaddr, 0, offset); + else + memset(kaddr + offset, 0, len); + flush_dcache_page(page); + kunmap(page); + } + ClearPageChecked(page); + set_page_dirty(page); + unlock_extent_cached(io_tree, page_start, page_end, &cached_state, + GFP_NOFS); + +out_unlock: + if (ret) + btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); + unlock_page(page); + page_cache_release(page); +out: + return ret; +} + +static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode, + u64 offset, u64 len) +{ + struct btrfs_trans_handle *trans; + int ret; + + /* + * Still need to make sure the inode looks like it's been updated so + * that any holes get logged if we fsync. + */ + if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) { + BTRFS_I(inode)->last_trans = root->fs_info->generation; + BTRFS_I(inode)->last_sub_trans = root->log_transid; + BTRFS_I(inode)->last_log_commit = root->last_log_commit; + return 0; + } + + /* + * 1 - for the one we're dropping + * 1 - for the one we're adding + * 1 - for updating the inode. + */ + trans = btrfs_start_transaction(root, 3); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + btrfs_end_transaction(trans, root); + return ret; + } + + ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset, + 0, 0, len, 0, len, 0, 0, 0); + if (ret) + btrfs_abort_transaction(trans, root, ret); + else + btrfs_update_inode(trans, root, inode); + btrfs_end_transaction(trans, root); + return ret; +} + +/* + * This function puts in dummy file extents for the area we're creating a hole + * for. So if we are truncating this file to a larger size we need to insert + * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for + * the range between oldsize and size + */ +int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct extent_map *em = NULL; + struct extent_state *cached_state = NULL; + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + u64 hole_start = ALIGN(oldsize, root->sectorsize); + u64 block_end = ALIGN(size, root->sectorsize); + u64 last_byte; + u64 cur_offset; + u64 hole_size; + int err = 0; + + /* + * If our size started in the middle of a page we need to zero out the + * rest of the page before we expand the i_size, otherwise we could + * expose stale data. + */ + err = btrfs_truncate_page(inode, oldsize, 0, 0); + if (err) + return err; + + if (size <= hole_start) + return 0; + + while (1) { + struct btrfs_ordered_extent *ordered; + + lock_extent_bits(io_tree, hole_start, block_end - 1, 0, + &cached_state); + ordered = btrfs_lookup_ordered_range(inode, hole_start, + block_end - hole_start); + if (!ordered) + break; + unlock_extent_cached(io_tree, hole_start, block_end - 1, + &cached_state, GFP_NOFS); + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + } + + cur_offset = hole_start; + while (1) { + em = btrfs_get_extent(inode, NULL, 0, cur_offset, + block_end - cur_offset, 0); + if (IS_ERR(em)) { + err = PTR_ERR(em); + em = NULL; + break; + } + last_byte = min(extent_map_end(em), block_end); + last_byte = ALIGN(last_byte , root->sectorsize); + if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { + struct extent_map *hole_em; + hole_size = last_byte - cur_offset; + + err = maybe_insert_hole(root, inode, cur_offset, + hole_size); + if (err) + break; + btrfs_drop_extent_cache(inode, cur_offset, + cur_offset + hole_size - 1, 0); + hole_em = alloc_extent_map(); + if (!hole_em) { + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &BTRFS_I(inode)->runtime_flags); + goto next; + } + hole_em->start = cur_offset; + hole_em->len = hole_size; + hole_em->orig_start = cur_offset; + + hole_em->block_start = EXTENT_MAP_HOLE; + hole_em->block_len = 0; + hole_em->orig_block_len = 0; + hole_em->ram_bytes = hole_size; + hole_em->bdev = root->fs_info->fs_devices->latest_bdev; + hole_em->compress_type = BTRFS_COMPRESS_NONE; + hole_em->generation = root->fs_info->generation; + + while (1) { + write_lock(&em_tree->lock); + err = add_extent_mapping(em_tree, hole_em, 1); + write_unlock(&em_tree->lock); + if (err != -EEXIST) + break; + btrfs_drop_extent_cache(inode, cur_offset, + cur_offset + + hole_size - 1, 0); + } + free_extent_map(hole_em); + } +next: + free_extent_map(em); + em = NULL; + cur_offset = last_byte; + if (cur_offset >= block_end) + break; + } + free_extent_map(em); + unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state, + GFP_NOFS); + return err; +} + +static int wait_snapshoting_atomic_t(atomic_t *a) +{ + schedule(); + return 0; +} + +static void wait_for_snapshot_creation(struct btrfs_root *root) +{ + while (true) { + int ret; + + ret = btrfs_start_write_no_snapshoting(root); + if (ret) + break; + wait_on_atomic_t(&root->will_be_snapshoted, + wait_snapshoting_atomic_t, + TASK_UNINTERRUPTIBLE); + } +} + +static int btrfs_setsize(struct inode *inode, struct iattr *attr) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + loff_t oldsize = i_size_read(inode); + loff_t newsize = attr->ia_size; + int mask = attr->ia_valid; + int ret; + + /* + * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a + * special case where we need to update the times despite not having + * these flags set. For all other operations the VFS set these flags + * explicitly if it wants a timestamp update. + */ + if (newsize != oldsize) { + inode_inc_iversion(inode); + if (!(mask & (ATTR_CTIME | ATTR_MTIME))) + inode->i_ctime = inode->i_mtime = + current_fs_time(inode->i_sb); + } + + if (newsize > oldsize) { + truncate_pagecache(inode, newsize); + /* + * Don't do an expanding truncate while snapshoting is ongoing. + * This is to ensure the snapshot captures a fully consistent + * state of this file - if the snapshot captures this expanding + * truncation, it must capture all writes that happened before + * this truncation. + */ + wait_for_snapshot_creation(root); + ret = btrfs_cont_expand(inode, oldsize, newsize); + if (ret) { + btrfs_end_write_no_snapshoting(root); + return ret; + } + + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + btrfs_end_write_no_snapshoting(root); + return PTR_ERR(trans); + } + + i_size_write(inode, newsize); + btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL); + ret = btrfs_update_inode(trans, root, inode); + btrfs_end_write_no_snapshoting(root); + btrfs_end_transaction(trans, root); + } else { + + /* + * We're truncating a file that used to have good data down to + * zero. Make sure it gets into the ordered flush list so that + * any new writes get down to disk quickly. + */ + if (newsize == 0) + set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, + &BTRFS_I(inode)->runtime_flags); + + /* + * 1 for the orphan item we're going to add + * 1 for the orphan item deletion. + */ + trans = btrfs_start_transaction(root, 2); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + /* + * We need to do this in case we fail at _any_ point during the + * actual truncate. Once we do the truncate_setsize we could + * invalidate pages which forces any outstanding ordered io to + * be instantly completed which will give us extents that need + * to be truncated. If we fail to get an orphan inode down we + * could have left over extents that were never meant to live, + * so we need to garuntee from this point on that everything + * will be consistent. + */ + ret = btrfs_orphan_add(trans, inode); + btrfs_end_transaction(trans, root); + if (ret) + return ret; + + /* we don't support swapfiles, so vmtruncate shouldn't fail */ + truncate_setsize(inode, newsize); + + /* Disable nonlocked read DIO to avoid the end less truncate */ + btrfs_inode_block_unlocked_dio(inode); + inode_dio_wait(inode); + btrfs_inode_resume_unlocked_dio(inode); + + ret = btrfs_truncate(inode); + if (ret && inode->i_nlink) { + int err; + + /* + * failed to truncate, disk_i_size is only adjusted down + * as we remove extents, so it should represent the true + * size of the inode, so reset the in memory size and + * delete our orphan entry. + */ + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + btrfs_orphan_del(NULL, inode); + return ret; + } + i_size_write(inode, BTRFS_I(inode)->disk_i_size); + err = btrfs_orphan_del(trans, inode); + if (err) + btrfs_abort_transaction(trans, root, err); + btrfs_end_transaction(trans, root); + } + } + + return ret; +} + +static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) +{ + struct inode *inode = d_inode(dentry); + struct btrfs_root *root = BTRFS_I(inode)->root; + int err; + + if (btrfs_root_readonly(root)) + return -EROFS; + + err = inode_change_ok(inode, attr); + if (err) + return err; + + if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { + err = btrfs_setsize(inode, attr); + if (err) + return err; + } + + if (attr->ia_valid) { + setattr_copy(inode, attr); + inode_inc_iversion(inode); + err = btrfs_dirty_inode(inode); + + if (!err && attr->ia_valid & ATTR_MODE) + err = posix_acl_chmod(inode, inode->i_mode); + } + + return err; +} + +/* + * While truncating the inode pages during eviction, we get the VFS calling + * btrfs_invalidatepage() against each page of the inode. This is slow because + * the calls to btrfs_invalidatepage() result in a huge amount of calls to + * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting + * extent_state structures over and over, wasting lots of time. + * + * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all + * those expensive operations on a per page basis and do only the ordered io + * finishing, while we release here the extent_map and extent_state structures, + * without the excessive merging and splitting. + */ +static void evict_inode_truncate_pages(struct inode *inode) +{ + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree; + struct rb_node *node; + + ASSERT(inode->i_state & I_FREEING); + truncate_inode_pages_final(&inode->i_data); + + write_lock(&map_tree->lock); + while (!RB_EMPTY_ROOT(&map_tree->map)) { + struct extent_map *em; + + node = rb_first(&map_tree->map); + em = rb_entry(node, struct extent_map, rb_node); + clear_bit(EXTENT_FLAG_PINNED, &em->flags); + clear_bit(EXTENT_FLAG_LOGGING, &em->flags); + remove_extent_mapping(map_tree, em); + free_extent_map(em); + if (need_resched()) { + write_unlock(&map_tree->lock); + cond_resched(); + write_lock(&map_tree->lock); + } + } + write_unlock(&map_tree->lock); + + spin_lock(&io_tree->lock); + while (!RB_EMPTY_ROOT(&io_tree->state)) { + struct extent_state *state; + struct extent_state *cached_state = NULL; + + node = rb_first(&io_tree->state); + state = rb_entry(node, struct extent_state, rb_node); + atomic_inc(&state->refs); + spin_unlock(&io_tree->lock); + + lock_extent_bits(io_tree, state->start, state->end, + 0, &cached_state); + clear_extent_bit(io_tree, state->start, state->end, + EXTENT_LOCKED | EXTENT_DIRTY | + EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | + EXTENT_DEFRAG, 1, 1, + &cached_state, GFP_NOFS); + free_extent_state(state); + + cond_resched(); + spin_lock(&io_tree->lock); + } + spin_unlock(&io_tree->lock); +} + +void btrfs_evict_inode(struct inode *inode) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_block_rsv *rsv, *global_rsv; + int steal_from_global = 0; + u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); + int ret; + + trace_btrfs_inode_evict(inode); + + evict_inode_truncate_pages(inode); + + if (inode->i_nlink && + ((btrfs_root_refs(&root->root_item) != 0 && + root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) || + btrfs_is_free_space_inode(inode))) + goto no_delete; + + if (is_bad_inode(inode)) { + btrfs_orphan_del(NULL, inode); + goto no_delete; + } + /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */ + btrfs_wait_ordered_range(inode, 0, (u64)-1); + + btrfs_free_io_failure_record(inode, 0, (u64)-1); + + if (root->fs_info->log_root_recovering) { + BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, + &BTRFS_I(inode)->runtime_flags)); + goto no_delete; + } + + if (inode->i_nlink > 0) { + BUG_ON(btrfs_root_refs(&root->root_item) != 0 && + root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID); + goto no_delete; + } + + ret = btrfs_commit_inode_delayed_inode(inode); + if (ret) { + btrfs_orphan_del(NULL, inode); + goto no_delete; + } + + rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); + if (!rsv) { + btrfs_orphan_del(NULL, inode); + goto no_delete; + } + rsv->size = min_size; + rsv->failfast = 1; + global_rsv = &root->fs_info->global_block_rsv; + + btrfs_i_size_write(inode, 0); + + /* + * This is a bit simpler than btrfs_truncate since we've already + * reserved our space for our orphan item in the unlink, so we just + * need to reserve some slack space in case we add bytes and update + * inode item when doing the truncate. + */ + while (1) { + ret = btrfs_block_rsv_refill(root, rsv, min_size, + BTRFS_RESERVE_FLUSH_LIMIT); + + /* + * Try and steal from the global reserve since we will + * likely not use this space anyway, we want to try as + * hard as possible to get this to work. + */ + if (ret) + steal_from_global++; + else + steal_from_global = 0; + ret = 0; + + /* + * steal_from_global == 0: we reserved stuff, hooray! + * steal_from_global == 1: we didn't reserve stuff, boo! + * steal_from_global == 2: we've committed, still not a lot of + * room but maybe we'll have room in the global reserve this + * time. + * steal_from_global == 3: abandon all hope! + */ + if (steal_from_global > 2) { + btrfs_warn(root->fs_info, + "Could not get space for a delete, will truncate on mount %d", + ret); + btrfs_orphan_del(NULL, inode); + btrfs_free_block_rsv(root, rsv); + goto no_delete; + } + + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + btrfs_orphan_del(NULL, inode); + btrfs_free_block_rsv(root, rsv); + goto no_delete; + } + + /* + * We can't just steal from the global reserve, we need tomake + * sure there is room to do it, if not we need to commit and try + * again. + */ + if (steal_from_global) { + if (!btrfs_check_space_for_delayed_refs(trans, root)) + ret = btrfs_block_rsv_migrate(global_rsv, rsv, + min_size); + else + ret = -ENOSPC; + } + + /* + * Couldn't steal from the global reserve, we have too much + * pending stuff built up, commit the transaction and try it + * again. + */ + if (ret) { + ret = btrfs_commit_transaction(trans, root); + if (ret) { + btrfs_orphan_del(NULL, inode); + btrfs_free_block_rsv(root, rsv); + goto no_delete; + } + continue; + } else { + steal_from_global = 0; + } + + trans->block_rsv = rsv; + + ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0); + if (ret != -ENOSPC && ret != -EAGAIN) + break; + + trans->block_rsv = &root->fs_info->trans_block_rsv; + btrfs_end_transaction(trans, root); + trans = NULL; + btrfs_btree_balance_dirty(root); + } + + btrfs_free_block_rsv(root, rsv); + + /* + * Errors here aren't a big deal, it just means we leave orphan items + * in the tree. They will be cleaned up on the next mount. + */ + if (ret == 0) { + trans->block_rsv = root->orphan_block_rsv; + btrfs_orphan_del(trans, inode); + } else { + btrfs_orphan_del(NULL, inode); + } + + trans->block_rsv = &root->fs_info->trans_block_rsv; + if (!(root == root->fs_info->tree_root || + root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)) + btrfs_return_ino(root, btrfs_ino(inode)); + + btrfs_end_transaction(trans, root); + btrfs_btree_balance_dirty(root); +no_delete: + btrfs_remove_delayed_node(inode); + clear_inode(inode); + return; +} + +/* + * this returns the key found in the dir entry in the location pointer. + * If no dir entries were found, location->objectid is 0. + */ +static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, + struct btrfs_key *location) +{ + const char *name = dentry->d_name.name; + int namelen = dentry->d_name.len; + struct btrfs_dir_item *di; + struct btrfs_path *path; + struct btrfs_root *root = BTRFS_I(dir)->root; + int ret = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name, + namelen, 0); + if (IS_ERR(di)) + ret = PTR_ERR(di); + + if (IS_ERR_OR_NULL(di)) + goto out_err; + + btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); +out: + btrfs_free_path(path); + return ret; +out_err: + location->objectid = 0; + goto out; +} + +/* + * when we hit a tree root in a directory, the btrfs part of the inode + * needs to be changed to reflect the root directory of the tree root. This + * is kind of like crossing a mount point. + */ +static int fixup_tree_root_location(struct btrfs_root *root, + struct inode *dir, + struct dentry *dentry, + struct btrfs_key *location, + struct btrfs_root **sub_root) +{ + struct btrfs_path *path; + struct btrfs_root *new_root; + struct btrfs_root_ref *ref; + struct extent_buffer *leaf; + struct btrfs_key key; + int ret; + int err = 0; + + path = btrfs_alloc_path(); + if (!path) { + err = -ENOMEM; + goto out; + } + + err = -ENOENT; + key.objectid = BTRFS_I(dir)->root->root_key.objectid; + key.type = BTRFS_ROOT_REF_KEY; + key.offset = location->objectid; + + ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path, + 0, 0); + if (ret) { + if (ret < 0) + err = ret; + goto out; + } + + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); + if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) || + btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len) + goto out; + + ret = memcmp_extent_buffer(leaf, dentry->d_name.name, + (unsigned long)(ref + 1), + dentry->d_name.len); + if (ret) + goto out; + + btrfs_release_path(path); + + new_root = btrfs_read_fs_root_no_name(root->fs_info, location); + if (IS_ERR(new_root)) { + err = PTR_ERR(new_root); + goto out; + } + + *sub_root = new_root; + location->objectid = btrfs_root_dirid(&new_root->root_item); + location->type = BTRFS_INODE_ITEM_KEY; + location->offset = 0; + err = 0; +out: + btrfs_free_path(path); + return err; +} + +static void inode_tree_add(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_inode *entry; + struct rb_node **p; + struct rb_node *parent; + struct rb_node *new = &BTRFS_I(inode)->rb_node; + u64 ino = btrfs_ino(inode); + + if (inode_unhashed(inode)) + return; + parent = NULL; + spin_lock(&root->inode_lock); + p = &root->inode_tree.rb_node; + while (*p) { + parent = *p; + entry = rb_entry(parent, struct btrfs_inode, rb_node); + + if (ino < btrfs_ino(&entry->vfs_inode)) + p = &parent->rb_left; + else if (ino > btrfs_ino(&entry->vfs_inode)) + p = &parent->rb_right; + else { + WARN_ON(!(entry->vfs_inode.i_state & + (I_WILL_FREE | I_FREEING))); + rb_replace_node(parent, new, &root->inode_tree); + RB_CLEAR_NODE(parent); + spin_unlock(&root->inode_lock); + return; + } + } + rb_link_node(new, parent, p); + rb_insert_color(new, &root->inode_tree); + spin_unlock(&root->inode_lock); +} + +static void inode_tree_del(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + int empty = 0; + + spin_lock(&root->inode_lock); + if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) { + rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree); + RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node); + empty = RB_EMPTY_ROOT(&root->inode_tree); + } + spin_unlock(&root->inode_lock); + + if (empty && btrfs_root_refs(&root->root_item) == 0) { + synchronize_srcu(&root->fs_info->subvol_srcu); + spin_lock(&root->inode_lock); + empty = RB_EMPTY_ROOT(&root->inode_tree); + spin_unlock(&root->inode_lock); + if (empty) + btrfs_add_dead_root(root); + } +} + +void btrfs_invalidate_inodes(struct btrfs_root *root) +{ + struct rb_node *node; + struct rb_node *prev; + struct btrfs_inode *entry; + struct inode *inode; + u64 objectid = 0; + + if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) + WARN_ON(btrfs_root_refs(&root->root_item) != 0); + + spin_lock(&root->inode_lock); +again: + node = root->inode_tree.rb_node; + prev = NULL; + while (node) { + prev = node; + entry = rb_entry(node, struct btrfs_inode, rb_node); + + if (objectid < btrfs_ino(&entry->vfs_inode)) + node = node->rb_left; + else if (objectid > btrfs_ino(&entry->vfs_inode)) + node = node->rb_right; + else + break; + } + if (!node) { + while (prev) { + entry = rb_entry(prev, struct btrfs_inode, rb_node); + if (objectid <= btrfs_ino(&entry->vfs_inode)) { + node = prev; + break; + } + prev = rb_next(prev); + } + } + while (node) { + entry = rb_entry(node, struct btrfs_inode, rb_node); + objectid = btrfs_ino(&entry->vfs_inode) + 1; + inode = igrab(&entry->vfs_inode); + if (inode) { + spin_unlock(&root->inode_lock); + if (atomic_read(&inode->i_count) > 1) + d_prune_aliases(inode); + /* + * btrfs_drop_inode will have it removed from + * the inode cache when its usage count + * hits zero. + */ + iput(inode); + cond_resched(); + spin_lock(&root->inode_lock); + goto again; + } + + if (cond_resched_lock(&root->inode_lock)) + goto again; + + node = rb_next(node); + } + spin_unlock(&root->inode_lock); +} + +static int btrfs_init_locked_inode(struct inode *inode, void *p) +{ + struct btrfs_iget_args *args = p; + inode->i_ino = args->location->objectid; + memcpy(&BTRFS_I(inode)->location, args->location, + sizeof(*args->location)); + BTRFS_I(inode)->root = args->root; + return 0; +} + +static int btrfs_find_actor(struct inode *inode, void *opaque) +{ + struct btrfs_iget_args *args = opaque; + return args->location->objectid == BTRFS_I(inode)->location.objectid && + args->root == BTRFS_I(inode)->root; +} + +static struct inode *btrfs_iget_locked(struct super_block *s, + struct btrfs_key *location, + struct btrfs_root *root) +{ + struct inode *inode; + struct btrfs_iget_args args; + unsigned long hashval = btrfs_inode_hash(location->objectid, root); + + args.location = location; + args.root = root; + + inode = iget5_locked(s, hashval, btrfs_find_actor, + btrfs_init_locked_inode, + (void *)&args); + return inode; +} + +/* Get an inode object given its location and corresponding root. + * Returns in *is_new if the inode was read from disk + */ +struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, + struct btrfs_root *root, int *new) +{ + struct inode *inode; + + inode = btrfs_iget_locked(s, location, root); + if (!inode) + return ERR_PTR(-ENOMEM); + + if (inode->i_state & I_NEW) { + btrfs_read_locked_inode(inode); + if (!is_bad_inode(inode)) { + inode_tree_add(inode); + unlock_new_inode(inode); + if (new) + *new = 1; + } else { + unlock_new_inode(inode); + iput(inode); + inode = ERR_PTR(-ESTALE); + } + } + + return inode; +} + +static struct inode *new_simple_dir(struct super_block *s, + struct btrfs_key *key, + struct btrfs_root *root) +{ + struct inode *inode = new_inode(s); + + if (!inode) + return ERR_PTR(-ENOMEM); + + BTRFS_I(inode)->root = root; + memcpy(&BTRFS_I(inode)->location, key, sizeof(*key)); + set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags); + + inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID; + inode->i_op = &btrfs_dir_ro_inode_operations; + inode->i_fop = &simple_dir_operations; + inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO; + inode->i_mtime = CURRENT_TIME; + inode->i_atime = inode->i_mtime; + inode->i_ctime = inode->i_mtime; + BTRFS_I(inode)->i_otime = inode->i_mtime; + + return inode; +} + +struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) +{ + struct inode *inode; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_root *sub_root = root; + struct btrfs_key location; + int index; + int ret = 0; + + if (dentry->d_name.len > BTRFS_NAME_LEN) + return ERR_PTR(-ENAMETOOLONG); + + ret = btrfs_inode_by_name(dir, dentry, &location); + if (ret < 0) + return ERR_PTR(ret); + + if (location.objectid == 0) + return ERR_PTR(-ENOENT); + + if (location.type == BTRFS_INODE_ITEM_KEY) { + inode = btrfs_iget(dir->i_sb, &location, root, NULL); + return inode; + } + + BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY); + + index = srcu_read_lock(&root->fs_info->subvol_srcu); + ret = fixup_tree_root_location(root, dir, dentry, + &location, &sub_root); + if (ret < 0) { + if (ret != -ENOENT) + inode = ERR_PTR(ret); + else + inode = new_simple_dir(dir->i_sb, &location, sub_root); + } else { + inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL); + } + srcu_read_unlock(&root->fs_info->subvol_srcu, index); + + if (!IS_ERR(inode) && root != sub_root) { + down_read(&root->fs_info->cleanup_work_sem); + if (!(inode->i_sb->s_flags & MS_RDONLY)) + ret = btrfs_orphan_cleanup(sub_root); + up_read(&root->fs_info->cleanup_work_sem); + if (ret) { + iput(inode); + inode = ERR_PTR(ret); + } + } + + return inode; +} + +static int btrfs_dentry_delete(const struct dentry *dentry) +{ + struct btrfs_root *root; + struct inode *inode = d_inode(dentry); + + if (!inode && !IS_ROOT(dentry)) + inode = d_inode(dentry->d_parent); + + if (inode) { + root = BTRFS_I(inode)->root; + if (btrfs_root_refs(&root->root_item) == 0) + return 1; + + if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) + return 1; + } + return 0; +} + +static void btrfs_dentry_release(struct dentry *dentry) +{ + kfree(dentry->d_fsdata); +} + +static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, + unsigned int flags) +{ + struct inode *inode; + + inode = btrfs_lookup_dentry(dir, dentry); + if (IS_ERR(inode)) { + if (PTR_ERR(inode) == -ENOENT) + inode = NULL; + else + return ERR_CAST(inode); + } + + return d_splice_alias(inode, dentry); +} + +unsigned char btrfs_filetype_table[] = { + DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK +}; + +static int btrfs_real_readdir(struct file *file, struct dir_context *ctx) +{ + struct inode *inode = file_inode(file); + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_item *item; + struct btrfs_dir_item *di; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_path *path; + struct list_head ins_list; + struct list_head del_list; + int ret; + struct extent_buffer *leaf; + int slot; + unsigned char d_type; + int over = 0; + u32 di_cur; + u32 di_total; + u32 di_len; + int key_type = BTRFS_DIR_INDEX_KEY; + char tmp_name[32]; + char *name_ptr; + int name_len; + int is_curr = 0; /* ctx->pos points to the current index? */ + + /* FIXME, use a real flag for deciding about the key type */ + if (root->fs_info->tree_root == root) + key_type = BTRFS_DIR_ITEM_KEY; + + if (!dir_emit_dots(file, ctx)) + return 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = 1; + + if (key_type == BTRFS_DIR_INDEX_KEY) { + INIT_LIST_HEAD(&ins_list); + INIT_LIST_HEAD(&del_list); + btrfs_get_delayed_items(inode, &ins_list, &del_list); + } + + key.type = key_type; + key.offset = ctx->pos; + key.objectid = btrfs_ino(inode); + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto err; + + while (1) { + leaf = path->nodes[0]; + slot = path->slots[0]; + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto err; + else if (ret > 0) + break; + continue; + } + + item = btrfs_item_nr(slot); + btrfs_item_key_to_cpu(leaf, &found_key, slot); + + if (found_key.objectid != key.objectid) + break; + if (found_key.type != key_type) + break; + if (found_key.offset < ctx->pos) + goto next; + if (key_type == BTRFS_DIR_INDEX_KEY && + btrfs_should_delete_dir_index(&del_list, + found_key.offset)) + goto next; + + ctx->pos = found_key.offset; + is_curr = 1; + + di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); + di_cur = 0; + di_total = btrfs_item_size(leaf, item); + + while (di_cur < di_total) { + struct btrfs_key location; + + if (verify_dir_item(root, leaf, di)) + break; + + name_len = btrfs_dir_name_len(leaf, di); + if (name_len <= sizeof(tmp_name)) { + name_ptr = tmp_name; + } else { + name_ptr = kmalloc(name_len, GFP_NOFS); + if (!name_ptr) { + ret = -ENOMEM; + goto err; + } + } + read_extent_buffer(leaf, name_ptr, + (unsigned long)(di + 1), name_len); + + d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)]; + btrfs_dir_item_key_to_cpu(leaf, di, &location); + + + /* is this a reference to our own snapshot? If so + * skip it. + * + * In contrast to old kernels, we insert the snapshot's + * dir item and dir index after it has been created, so + * we won't find a reference to our own snapshot. We + * still keep the following code for backward + * compatibility. + */ + if (location.type == BTRFS_ROOT_ITEM_KEY && + location.objectid == root->root_key.objectid) { + over = 0; + goto skip; + } + over = !dir_emit(ctx, name_ptr, name_len, + location.objectid, d_type); + +skip: + if (name_ptr != tmp_name) + kfree(name_ptr); + + if (over) + goto nopos; + di_len = btrfs_dir_name_len(leaf, di) + + btrfs_dir_data_len(leaf, di) + sizeof(*di); + di_cur += di_len; + di = (struct btrfs_dir_item *)((char *)di + di_len); + } +next: + path->slots[0]++; + } + + if (key_type == BTRFS_DIR_INDEX_KEY) { + if (is_curr) + ctx->pos++; + ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list); + if (ret) + goto nopos; + } + + /* Reached end of directory/root. Bump pos past the last item. */ + ctx->pos++; + + /* + * Stop new entries from being returned after we return the last + * entry. + * + * New directory entries are assigned a strictly increasing + * offset. This means that new entries created during readdir + * are *guaranteed* to be seen in the future by that readdir. + * This has broken buggy programs which operate on names as + * they're returned by readdir. Until we re-use freed offsets + * we have this hack to stop new entries from being returned + * under the assumption that they'll never reach this huge + * offset. + * + * This is being careful not to overflow 32bit loff_t unless the + * last entry requires it because doing so has broken 32bit apps + * in the past. + */ + if (key_type == BTRFS_DIR_INDEX_KEY) { + if (ctx->pos >= INT_MAX) + ctx->pos = LLONG_MAX; + else + ctx->pos = INT_MAX; + } +nopos: + ret = 0; +err: + if (key_type == BTRFS_DIR_INDEX_KEY) + btrfs_put_delayed_items(&ins_list, &del_list); + btrfs_free_path(path); + return ret; +} + +int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + int ret = 0; + bool nolock = false; + + if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) + return 0; + + if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode)) + nolock = true; + + if (wbc->sync_mode == WB_SYNC_ALL) { + if (nolock) + trans = btrfs_join_transaction_nolock(root); + else + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) + return PTR_ERR(trans); + ret = btrfs_commit_transaction(trans, root); + } + return ret; +} + +/* + * This is somewhat expensive, updating the tree every time the + * inode changes. But, it is most likely to find the inode in cache. + * FIXME, needs more benchmarking...there are no reasons other than performance + * to keep or drop this code. + */ +static int btrfs_dirty_inode(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + int ret; + + if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) + return 0; + + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = btrfs_update_inode(trans, root, inode); + if (ret && ret == -ENOSPC) { + /* whoops, lets try again with the full transaction */ + btrfs_end_transaction(trans, root); + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = btrfs_update_inode(trans, root, inode); + } + btrfs_end_transaction(trans, root); + if (BTRFS_I(inode)->delayed_node) + btrfs_balance_delayed_items(root); + + return ret; +} + +/* + * This is a copy of file_update_time. We need this so we can return error on + * ENOSPC for updating the inode in the case of file write and mmap writes. + */ +static int btrfs_update_time(struct inode *inode, struct timespec *now, + int flags) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + + if (btrfs_root_readonly(root)) + return -EROFS; + + if (flags & S_VERSION) + inode_inc_iversion(inode); + if (flags & S_CTIME) + inode->i_ctime = *now; + if (flags & S_MTIME) + inode->i_mtime = *now; + if (flags & S_ATIME) + inode->i_atime = *now; + return btrfs_dirty_inode(inode); +} + +/* + * find the highest existing sequence number in a directory + * and then set the in-memory index_cnt variable to reflect + * free sequence numbers + */ +static int btrfs_set_inode_index_count(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_key key, found_key; + struct btrfs_path *path; + struct extent_buffer *leaf; + int ret; + + key.objectid = btrfs_ino(inode); + key.type = BTRFS_DIR_INDEX_KEY; + key.offset = (u64)-1; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + /* FIXME: we should be able to handle this */ + if (ret == 0) + goto out; + ret = 0; + + /* + * MAGIC NUMBER EXPLANATION: + * since we search a directory based on f_pos we have to start at 2 + * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody + * else has to start at 2 + */ + if (path->slots[0] == 0) { + BTRFS_I(inode)->index_cnt = 2; + goto out; + } + + path->slots[0]--; + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + if (found_key.objectid != btrfs_ino(inode) || + found_key.type != BTRFS_DIR_INDEX_KEY) { + BTRFS_I(inode)->index_cnt = 2; + goto out; + } + + BTRFS_I(inode)->index_cnt = found_key.offset + 1; +out: + btrfs_free_path(path); + return ret; +} + +/* + * helper to find a free sequence number in a given directory. This current + * code is very simple, later versions will do smarter things in the btree + */ +int btrfs_set_inode_index(struct inode *dir, u64 *index) +{ + int ret = 0; + + if (BTRFS_I(dir)->index_cnt == (u64)-1) { + ret = btrfs_inode_delayed_dir_index_count(dir); + if (ret) { + ret = btrfs_set_inode_index_count(dir); + if (ret) + return ret; + } + } + + *index = BTRFS_I(dir)->index_cnt; + BTRFS_I(dir)->index_cnt++; + + return ret; +} + +static int btrfs_insert_inode_locked(struct inode *inode) +{ + struct btrfs_iget_args args; + args.location = &BTRFS_I(inode)->location; + args.root = BTRFS_I(inode)->root; + + return insert_inode_locked4(inode, + btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root), + btrfs_find_actor, &args); +} + +static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *dir, + const char *name, int name_len, + u64 ref_objectid, u64 objectid, + umode_t mode, u64 *index) +{ + struct inode *inode; + struct btrfs_inode_item *inode_item; + struct btrfs_key *location; + struct btrfs_path *path; + struct btrfs_inode_ref *ref; + struct btrfs_key key[2]; + u32 sizes[2]; + int nitems = name ? 2 : 1; + unsigned long ptr; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return ERR_PTR(-ENOMEM); + + inode = new_inode(root->fs_info->sb); + if (!inode) { + btrfs_free_path(path); + return ERR_PTR(-ENOMEM); + } + + /* + * O_TMPFILE, set link count to 0, so that after this point, + * we fill in an inode item with the correct link count. + */ + if (!name) + set_nlink(inode, 0); + + /* + * we have to initialize this early, so we can reclaim the inode + * number if we fail afterwards in this function. + */ + inode->i_ino = objectid; + + if (dir && name) { + trace_btrfs_inode_request(dir); + + ret = btrfs_set_inode_index(dir, index); + if (ret) { + btrfs_free_path(path); + iput(inode); + return ERR_PTR(ret); + } + } else if (dir) { + *index = 0; + } + /* + * index_cnt is ignored for everything but a dir, + * btrfs_get_inode_index_count has an explanation for the magic + * number + */ + BTRFS_I(inode)->index_cnt = 2; + BTRFS_I(inode)->dir_index = *index; + BTRFS_I(inode)->root = root; + BTRFS_I(inode)->generation = trans->transid; + inode->i_generation = BTRFS_I(inode)->generation; + + /* + * We could have gotten an inode number from somebody who was fsynced + * and then removed in this same transaction, so let's just set full + * sync since it will be a full sync anyway and this will blow away the + * old info in the log. + */ + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); + + key[0].objectid = objectid; + key[0].type = BTRFS_INODE_ITEM_KEY; + key[0].offset = 0; + + sizes[0] = sizeof(struct btrfs_inode_item); + + if (name) { + /* + * Start new inodes with an inode_ref. This is slightly more + * efficient for small numbers of hard links since they will + * be packed into one item. Extended refs will kick in if we + * add more hard links than can fit in the ref item. + */ + key[1].objectid = objectid; + key[1].type = BTRFS_INODE_REF_KEY; + key[1].offset = ref_objectid; + + sizes[1] = name_len + sizeof(*ref); + } + + location = &BTRFS_I(inode)->location; + location->objectid = objectid; + location->offset = 0; + location->type = BTRFS_INODE_ITEM_KEY; + + ret = btrfs_insert_inode_locked(inode); + if (ret < 0) + goto fail; + + path->leave_spinning = 1; + ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems); + if (ret != 0) + goto fail_unlock; + + inode_init_owner(inode, dir, mode); + inode_set_bytes(inode, 0); + + inode->i_mtime = CURRENT_TIME; + inode->i_atime = inode->i_mtime; + inode->i_ctime = inode->i_mtime; + BTRFS_I(inode)->i_otime = inode->i_mtime; + + inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_inode_item); + memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item, + sizeof(*inode_item)); + fill_inode_item(trans, path->nodes[0], inode_item, inode); + + if (name) { + ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, + struct btrfs_inode_ref); + btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); + btrfs_set_inode_ref_index(path->nodes[0], ref, *index); + ptr = (unsigned long)(ref + 1); + write_extent_buffer(path->nodes[0], name, ptr, name_len); + } + + btrfs_mark_buffer_dirty(path->nodes[0]); + btrfs_free_path(path); + + btrfs_inherit_iflags(inode, dir); + + if (S_ISREG(mode)) { + if (btrfs_test_opt(root, NODATASUM)) + BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; + if (btrfs_test_opt(root, NODATACOW)) + BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW | + BTRFS_INODE_NODATASUM; + } + + inode_tree_add(inode); + + trace_btrfs_inode_new(inode); + btrfs_set_inode_last_trans(trans, inode); + + btrfs_update_root_times(trans, root); + + ret = btrfs_inode_inherit_props(trans, inode, dir); + if (ret) + btrfs_err(root->fs_info, + "error inheriting props for ino %llu (root %llu): %d", + btrfs_ino(inode), root->root_key.objectid, ret); + + return inode; + +fail_unlock: + unlock_new_inode(inode); +fail: + if (dir && name) + BTRFS_I(dir)->index_cnt--; + btrfs_free_path(path); + iput(inode); + return ERR_PTR(ret); +} + +static inline u8 btrfs_inode_type(struct inode *inode) +{ + return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; +} + +/* + * utility function to add 'inode' into 'parent_inode' with + * a give name and a given sequence number. + * if 'add_backref' is true, also insert a backref from the + * inode to the parent directory. + */ +int btrfs_add_link(struct btrfs_trans_handle *trans, + struct inode *parent_inode, struct inode *inode, + const char *name, int name_len, int add_backref, u64 index) +{ + int ret = 0; + struct btrfs_key key; + struct btrfs_root *root = BTRFS_I(parent_inode)->root; + u64 ino = btrfs_ino(inode); + u64 parent_ino = btrfs_ino(parent_inode); + + if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { + memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key)); + } else { + key.objectid = ino; + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + } + + if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { + ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, + key.objectid, root->root_key.objectid, + parent_ino, index, name, name_len); + } else if (add_backref) { + ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino, + parent_ino, index); + } + + /* Nothing to clean up yet */ + if (ret) + return ret; + + ret = btrfs_insert_dir_item(trans, root, name, name_len, + parent_inode, &key, + btrfs_inode_type(inode), index); + if (ret == -EEXIST || ret == -EOVERFLOW) + goto fail_dir_item; + else if (ret) { + btrfs_abort_transaction(trans, root, ret); + return ret; + } + + btrfs_i_size_write(parent_inode, parent_inode->i_size + + name_len * 2); + inode_inc_iversion(parent_inode); + parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME; + ret = btrfs_update_inode(trans, root, parent_inode); + if (ret) + btrfs_abort_transaction(trans, root, ret); + return ret; + +fail_dir_item: + if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { + u64 local_index; + int err; + err = btrfs_del_root_ref(trans, root->fs_info->tree_root, + key.objectid, root->root_key.objectid, + parent_ino, &local_index, name, name_len); + + } else if (add_backref) { + u64 local_index; + int err; + + err = btrfs_del_inode_ref(trans, root, name, name_len, + ino, parent_ino, &local_index); + } + return ret; +} + +static int btrfs_add_nondir(struct btrfs_trans_handle *trans, + struct inode *dir, struct dentry *dentry, + struct inode *inode, int backref, u64 index) +{ + int err = btrfs_add_link(trans, dir, inode, + dentry->d_name.name, dentry->d_name.len, + backref, index); + if (err > 0) + err = -EEXIST; + return err; +} + +static int btrfs_mknod(struct inode *dir, struct dentry *dentry, + umode_t mode, dev_t rdev) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct inode *inode = NULL; + int err; + int drop_inode = 0; + u64 objectid; + u64 index = 0; + + if (!new_valid_dev(rdev)) + return -EINVAL; + + /* + * 2 for inode item and ref + * 2 for dir items + * 1 for xattr if selinux is on + */ + trans = btrfs_start_transaction(root, 5); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + err = btrfs_find_free_ino(root, &objectid); + if (err) + goto out_unlock; + + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, + dentry->d_name.len, btrfs_ino(dir), objectid, + mode, &index); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_unlock; + } + + /* + * If the active LSM wants to access the inode during + * d_instantiate it needs these. Smack checks to see + * if the filesystem supports xattrs by looking at the + * ops vector. + */ + inode->i_op = &btrfs_special_inode_operations; + init_special_inode(inode, inode->i_mode, rdev); + + err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); + if (err) + goto out_unlock_inode; + + err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); + if (err) { + goto out_unlock_inode; + } else { + btrfs_update_inode(trans, root, inode); + unlock_new_inode(inode); + d_instantiate(dentry, inode); + } + +out_unlock: + btrfs_end_transaction(trans, root); + btrfs_balance_delayed_items(root); + btrfs_btree_balance_dirty(root); + if (drop_inode) { + inode_dec_link_count(inode); + iput(inode); + } + return err; + +out_unlock_inode: + drop_inode = 1; + unlock_new_inode(inode); + goto out_unlock; + +} + +static int btrfs_create(struct inode *dir, struct dentry *dentry, + umode_t mode, bool excl) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct inode *inode = NULL; + int drop_inode_on_err = 0; + int err; + u64 objectid; + u64 index = 0; + + /* + * 2 for inode item and ref + * 2 for dir items + * 1 for xattr if selinux is on + */ + trans = btrfs_start_transaction(root, 5); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + err = btrfs_find_free_ino(root, &objectid); + if (err) + goto out_unlock; + + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, + dentry->d_name.len, btrfs_ino(dir), objectid, + mode, &index); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_unlock; + } + drop_inode_on_err = 1; + /* + * If the active LSM wants to access the inode during + * d_instantiate it needs these. Smack checks to see + * if the filesystem supports xattrs by looking at the + * ops vector. + */ + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; + inode->i_mapping->a_ops = &btrfs_aops; + + err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); + if (err) + goto out_unlock_inode; + + err = btrfs_update_inode(trans, root, inode); + if (err) + goto out_unlock_inode; + + err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); + if (err) + goto out_unlock_inode; + + BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; + unlock_new_inode(inode); + d_instantiate(dentry, inode); + +out_unlock: + btrfs_end_transaction(trans, root); + if (err && drop_inode_on_err) { + inode_dec_link_count(inode); + iput(inode); + } + btrfs_balance_delayed_items(root); + btrfs_btree_balance_dirty(root); + return err; + +out_unlock_inode: + unlock_new_inode(inode); + goto out_unlock; + +} + +static int btrfs_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *dentry) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct inode *inode = d_inode(old_dentry); + u64 index; + int err; + int drop_inode = 0; + + /* do not allow sys_link's with other subvols of the same device */ + if (root->objectid != BTRFS_I(inode)->root->objectid) + return -EXDEV; + + if (inode->i_nlink >= BTRFS_LINK_MAX) + return -EMLINK; + + err = btrfs_set_inode_index(dir, &index); + if (err) + goto fail; + + /* + * 2 items for inode and inode ref + * 2 items for dir items + * 1 item for parent inode + */ + trans = btrfs_start_transaction(root, 5); + if (IS_ERR(trans)) { + err = PTR_ERR(trans); + goto fail; + } + + /* There are several dir indexes for this inode, clear the cache. */ + BTRFS_I(inode)->dir_index = 0ULL; + inc_nlink(inode); + inode_inc_iversion(inode); + inode->i_ctime = CURRENT_TIME; + ihold(inode); + set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags); + + err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index); + + if (err) { + drop_inode = 1; + } else { + struct dentry *parent = dentry->d_parent; + err = btrfs_update_inode(trans, root, inode); + if (err) + goto fail; + if (inode->i_nlink == 1) { + /* + * If new hard link count is 1, it's a file created + * with open(2) O_TMPFILE flag. + */ + err = btrfs_orphan_del(trans, inode); + if (err) + goto fail; + } + d_instantiate(dentry, inode); + btrfs_log_new_name(trans, inode, NULL, parent); + } + + btrfs_end_transaction(trans, root); + btrfs_balance_delayed_items(root); +fail: + if (drop_inode) { + inode_dec_link_count(inode); + iput(inode); + } + btrfs_btree_balance_dirty(root); + return err; +} + +static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + struct inode *inode = NULL; + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + int err = 0; + int drop_on_err = 0; + u64 objectid = 0; + u64 index = 0; + + /* + * 2 items for inode and ref + * 2 items for dir items + * 1 for xattr if selinux is on + */ + trans = btrfs_start_transaction(root, 5); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + err = btrfs_find_free_ino(root, &objectid); + if (err) + goto out_fail; + + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, + dentry->d_name.len, btrfs_ino(dir), objectid, + S_IFDIR | mode, &index); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_fail; + } + + drop_on_err = 1; + /* these must be set before we unlock the inode */ + inode->i_op = &btrfs_dir_inode_operations; + inode->i_fop = &btrfs_dir_file_operations; + + err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); + if (err) + goto out_fail_inode; + + btrfs_i_size_write(inode, 0); + err = btrfs_update_inode(trans, root, inode); + if (err) + goto out_fail_inode; + + err = btrfs_add_link(trans, dir, inode, dentry->d_name.name, + dentry->d_name.len, 0, index); + if (err) + goto out_fail_inode; + + d_instantiate(dentry, inode); + /* + * mkdir is special. We're unlocking after we call d_instantiate + * to avoid a race with nfsd calling d_instantiate. + */ + unlock_new_inode(inode); + drop_on_err = 0; + +out_fail: + btrfs_end_transaction(trans, root); + if (drop_on_err) { + inode_dec_link_count(inode); + iput(inode); + } + btrfs_balance_delayed_items(root); + btrfs_btree_balance_dirty(root); + return err; + +out_fail_inode: + unlock_new_inode(inode); + goto out_fail; +} + +/* Find next extent map of a given extent map, caller needs to ensure locks */ +static struct extent_map *next_extent_map(struct extent_map *em) +{ + struct rb_node *next; + + next = rb_next(&em->rb_node); + if (!next) + return NULL; + return container_of(next, struct extent_map, rb_node); +} + +static struct extent_map *prev_extent_map(struct extent_map *em) +{ + struct rb_node *prev; + + prev = rb_prev(&em->rb_node); + if (!prev) + return NULL; + return container_of(prev, struct extent_map, rb_node); +} + +/* helper for btfs_get_extent. Given an existing extent in the tree, + * the existing extent is the nearest extent to map_start, + * and an extent that you want to insert, deal with overlap and insert + * the best fitted new extent into the tree. + */ +static int merge_extent_mapping(struct extent_map_tree *em_tree, + struct extent_map *existing, + struct extent_map *em, + u64 map_start) +{ + struct extent_map *prev; + struct extent_map *next; + u64 start; + u64 end; + u64 start_diff; + + BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); + + if (existing->start > map_start) { + next = existing; + prev = prev_extent_map(next); + } else { + prev = existing; + next = next_extent_map(prev); + } + + start = prev ? extent_map_end(prev) : em->start; + start = max_t(u64, start, em->start); + end = next ? next->start : extent_map_end(em); + end = min_t(u64, end, extent_map_end(em)); + start_diff = start - em->start; + em->start = start; + em->len = end - start; + if (em->block_start < EXTENT_MAP_LAST_BYTE && + !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { + em->block_start += start_diff; + em->block_len -= start_diff; + } + return add_extent_mapping(em_tree, em, 0); +} + +static noinline int uncompress_inline(struct btrfs_path *path, + struct inode *inode, struct page *page, + size_t pg_offset, u64 extent_offset, + struct btrfs_file_extent_item *item) +{ + int ret; + struct extent_buffer *leaf = path->nodes[0]; + char *tmp; + size_t max_size; + unsigned long inline_size; + unsigned long ptr; + int compress_type; + + WARN_ON(pg_offset != 0); + compress_type = btrfs_file_extent_compression(leaf, item); + max_size = btrfs_file_extent_ram_bytes(leaf, item); + inline_size = btrfs_file_extent_inline_item_len(leaf, + btrfs_item_nr(path->slots[0])); + tmp = kmalloc(inline_size, GFP_NOFS); + if (!tmp) + return -ENOMEM; + ptr = btrfs_file_extent_inline_start(item); + + read_extent_buffer(leaf, tmp, ptr, inline_size); + + max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size); + ret = btrfs_decompress(compress_type, tmp, page, + extent_offset, inline_size, max_size); + kfree(tmp); + return ret; +} + +/* + * a bit scary, this does extent mapping from logical file offset to the disk. + * the ugly parts come from merging extents from the disk with the in-ram + * representation. This gets more complex because of the data=ordered code, + * where the in-ram extents might be locked pending data=ordered completion. + * + * This also copies inline extents directly into the page. + */ + +struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, + size_t pg_offset, u64 start, u64 len, + int create) +{ + int ret; + int err = 0; + u64 extent_start = 0; + u64 extent_end = 0; + u64 objectid = btrfs_ino(inode); + u32 found_type; + struct btrfs_path *path = NULL; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_file_extent_item *item; + struct extent_buffer *leaf; + struct btrfs_key found_key; + struct extent_map *em = NULL; + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_trans_handle *trans = NULL; + const bool new_inline = !page || create; + +again: + read_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, start, len); + if (em) + em->bdev = root->fs_info->fs_devices->latest_bdev; + read_unlock(&em_tree->lock); + + if (em) { + if (em->start > start || em->start + em->len <= start) + free_extent_map(em); + else if (em->block_start == EXTENT_MAP_INLINE && page) + free_extent_map(em); + else + goto out; + } + em = alloc_extent_map(); + if (!em) { + err = -ENOMEM; + goto out; + } + em->bdev = root->fs_info->fs_devices->latest_bdev; + em->start = EXTENT_MAP_HOLE; + em->orig_start = EXTENT_MAP_HOLE; + em->len = (u64)-1; + em->block_len = (u64)-1; + + if (!path) { + path = btrfs_alloc_path(); + if (!path) { + err = -ENOMEM; + goto out; + } + /* + * Chances are we'll be called again, so go ahead and do + * readahead + */ + path->reada = 1; + } + + ret = btrfs_lookup_file_extent(trans, root, path, + objectid, start, trans != NULL); + if (ret < 0) { + err = ret; + goto out; + } + + if (ret != 0) { + if (path->slots[0] == 0) + goto not_found; + path->slots[0]--; + } + + leaf = path->nodes[0]; + item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + /* are we inside the extent that was found? */ + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + found_type = found_key.type; + if (found_key.objectid != objectid || + found_type != BTRFS_EXTENT_DATA_KEY) { + /* + * If we backup past the first extent we want to move forward + * and see if there is an extent in front of us, otherwise we'll + * say there is a hole for our whole search range which can + * cause problems. + */ + extent_end = start; + goto next; + } + + found_type = btrfs_file_extent_type(leaf, item); + extent_start = found_key.offset; + if (found_type == BTRFS_FILE_EXTENT_REG || + found_type == BTRFS_FILE_EXTENT_PREALLOC) { + extent_end = extent_start + + btrfs_file_extent_num_bytes(leaf, item); + } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { + size_t size; + size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); + extent_end = ALIGN(extent_start + size, root->sectorsize); + } +next: + if (start >= extent_end) { + path->slots[0]++; + if (path->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) { + err = ret; + goto out; + } + if (ret > 0) + goto not_found; + leaf = path->nodes[0]; + } + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + if (found_key.objectid != objectid || + found_key.type != BTRFS_EXTENT_DATA_KEY) + goto not_found; + if (start + len <= found_key.offset) + goto not_found; + if (start > found_key.offset) + goto next; + em->start = start; + em->orig_start = start; + em->len = found_key.offset - start; + goto not_found_em; + } + + btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em); + + if (found_type == BTRFS_FILE_EXTENT_REG || + found_type == BTRFS_FILE_EXTENT_PREALLOC) { + goto insert; + } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { + unsigned long ptr; + char *map; + size_t size; + size_t extent_offset; + size_t copy_size; + + if (new_inline) + goto out; + + size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); + extent_offset = page_offset(page) + pg_offset - extent_start; + copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset, + size - extent_offset); + em->start = extent_start + extent_offset; + em->len = ALIGN(copy_size, root->sectorsize); + em->orig_block_len = em->len; + em->orig_start = em->start; + ptr = btrfs_file_extent_inline_start(item) + extent_offset; + if (create == 0 && !PageUptodate(page)) { + if (btrfs_file_extent_compression(leaf, item) != + BTRFS_COMPRESS_NONE) { + ret = uncompress_inline(path, inode, page, + pg_offset, + extent_offset, item); + if (ret) { + err = ret; + goto out; + } + } else { + map = kmap(page); + read_extent_buffer(leaf, map + pg_offset, ptr, + copy_size); + if (pg_offset + copy_size < PAGE_CACHE_SIZE) { + memset(map + pg_offset + copy_size, 0, + PAGE_CACHE_SIZE - pg_offset - + copy_size); + } + kunmap(page); + } + flush_dcache_page(page); + } else if (create && PageUptodate(page)) { + BUG(); + if (!trans) { + kunmap(page); + free_extent_map(em); + em = NULL; + + btrfs_release_path(path); + trans = btrfs_join_transaction(root); + + if (IS_ERR(trans)) + return ERR_CAST(trans); + goto again; + } + map = kmap(page); + write_extent_buffer(leaf, map + pg_offset, ptr, + copy_size); + kunmap(page); + btrfs_mark_buffer_dirty(leaf); + } + set_extent_uptodate(io_tree, em->start, + extent_map_end(em) - 1, NULL, GFP_NOFS); + goto insert; + } +not_found: + em->start = start; + em->orig_start = start; + em->len = len; +not_found_em: + em->block_start = EXTENT_MAP_HOLE; + set_bit(EXTENT_FLAG_VACANCY, &em->flags); +insert: + btrfs_release_path(path); + if (em->start > start || extent_map_end(em) <= start) { + btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]", + em->start, em->len, start, len); + err = -EIO; + goto out; + } + + err = 0; + write_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em, 0); + /* it is possible that someone inserted the extent into the tree + * while we had the lock dropped. It is also possible that + * an overlapping map exists in the tree + */ + if (ret == -EEXIST) { + struct extent_map *existing; + + ret = 0; + + existing = search_extent_mapping(em_tree, start, len); + /* + * existing will always be non-NULL, since there must be + * extent causing the -EEXIST. + */ + if (start >= extent_map_end(existing) || + start <= existing->start) { + /* + * The existing extent map is the one nearest to + * the [start, start + len) range which overlaps + */ + err = merge_extent_mapping(em_tree, existing, + em, start); + free_extent_map(existing); + if (err) { + free_extent_map(em); + em = NULL; + } + } else { + free_extent_map(em); + em = existing; + err = 0; + } + } + write_unlock(&em_tree->lock); +out: + + trace_btrfs_get_extent(root, em); + + if (path) + btrfs_free_path(path); + if (trans) { + ret = btrfs_end_transaction(trans, root); + if (!err) + err = ret; + } + if (err) { + free_extent_map(em); + return ERR_PTR(err); + } + BUG_ON(!em); /* Error is always set */ + return em; +} + +struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page, + size_t pg_offset, u64 start, u64 len, + int create) +{ + struct extent_map *em; + struct extent_map *hole_em = NULL; + u64 range_start = start; + u64 end; + u64 found; + u64 found_end; + int err = 0; + + em = btrfs_get_extent(inode, page, pg_offset, start, len, create); + if (IS_ERR(em)) + return em; + if (em) { + /* + * if our em maps to + * - a hole or + * - a pre-alloc extent, + * there might actually be delalloc bytes behind it. + */ + if (em->block_start != EXTENT_MAP_HOLE && + !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) + return em; + else + hole_em = em; + } + + /* check to see if we've wrapped (len == -1 or similar) */ + end = start + len; + if (end < start) + end = (u64)-1; + else + end -= 1; + + em = NULL; + + /* ok, we didn't find anything, lets look for delalloc */ + found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start, + end, len, EXTENT_DELALLOC, 1); + found_end = range_start + found; + if (found_end < range_start) + found_end = (u64)-1; + + /* + * we didn't find anything useful, return + * the original results from get_extent() + */ + if (range_start > end || found_end <= start) { + em = hole_em; + hole_em = NULL; + goto out; + } + + /* adjust the range_start to make sure it doesn't + * go backwards from the start they passed in + */ + range_start = max(start, range_start); + found = found_end - range_start; + + if (found > 0) { + u64 hole_start = start; + u64 hole_len = len; + + em = alloc_extent_map(); + if (!em) { + err = -ENOMEM; + goto out; + } + /* + * when btrfs_get_extent can't find anything it + * returns one huge hole + * + * make sure what it found really fits our range, and + * adjust to make sure it is based on the start from + * the caller + */ + if (hole_em) { + u64 calc_end = extent_map_end(hole_em); + + if (calc_end <= start || (hole_em->start > end)) { + free_extent_map(hole_em); + hole_em = NULL; + } else { + hole_start = max(hole_em->start, start); + hole_len = calc_end - hole_start; + } + } + em->bdev = NULL; + if (hole_em && range_start > hole_start) { + /* our hole starts before our delalloc, so we + * have to return just the parts of the hole + * that go until the delalloc starts + */ + em->len = min(hole_len, + range_start - hole_start); + em->start = hole_start; + em->orig_start = hole_start; + /* + * don't adjust block start at all, + * it is fixed at EXTENT_MAP_HOLE + */ + em->block_start = hole_em->block_start; + em->block_len = hole_len; + if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags)) + set_bit(EXTENT_FLAG_PREALLOC, &em->flags); + } else { + em->start = range_start; + em->len = found; + em->orig_start = range_start; + em->block_start = EXTENT_MAP_DELALLOC; + em->block_len = found; + } + } else if (hole_em) { + return hole_em; + } +out: + + free_extent_map(hole_em); + if (err) { + free_extent_map(em); + return ERR_PTR(err); + } + return em; +} + +static struct extent_map *btrfs_new_extent_direct(struct inode *inode, + u64 start, u64 len) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_map *em; + struct btrfs_key ins; + u64 alloc_hint; + int ret; + + alloc_hint = get_extent_allocation_hint(inode, start, len); + ret = btrfs_reserve_extent(root, len, root->sectorsize, 0, + alloc_hint, &ins, 1, 1); + if (ret) + return ERR_PTR(ret); + + em = create_pinned_em(inode, start, ins.offset, start, ins.objectid, + ins.offset, ins.offset, ins.offset, 0); + if (IS_ERR(em)) { + btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); + return em; + } + + ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid, + ins.offset, ins.offset, 0); + if (ret) { + btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); + free_extent_map(em); + return ERR_PTR(ret); + } + + return em; +} + +/* + * returns 1 when the nocow is safe, < 1 on error, 0 if the + * block must be cow'd + */ +noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, + u64 *orig_start, u64 *orig_block_len, + u64 *ram_bytes) +{ + struct btrfs_trans_handle *trans; + struct btrfs_path *path; + int ret; + struct extent_buffer *leaf; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_file_extent_item *fi; + struct btrfs_key key; + u64 disk_bytenr; + u64 backref_offset; + u64 extent_end; + u64 num_bytes; + int slot; + int found_type; + bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), + offset, 0); + if (ret < 0) + goto out; + + slot = path->slots[0]; + if (ret == 1) { + if (slot == 0) { + /* can't find the item, must cow */ + ret = 0; + goto out; + } + slot--; + } + ret = 0; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid != btrfs_ino(inode) || + key.type != BTRFS_EXTENT_DATA_KEY) { + /* not our file or wrong item type, must cow */ + goto out; + } + + if (key.offset > offset) { + /* Wrong offset, must cow */ + goto out; + } + + fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); + found_type = btrfs_file_extent_type(leaf, fi); + if (found_type != BTRFS_FILE_EXTENT_REG && + found_type != BTRFS_FILE_EXTENT_PREALLOC) { + /* not a regular extent, must cow */ + goto out; + } + + if (!nocow && found_type == BTRFS_FILE_EXTENT_REG) + goto out; + + extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); + if (extent_end <= offset) + goto out; + + disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); + if (disk_bytenr == 0) + goto out; + + if (btrfs_file_extent_compression(leaf, fi) || + btrfs_file_extent_encryption(leaf, fi) || + btrfs_file_extent_other_encoding(leaf, fi)) + goto out; + + backref_offset = btrfs_file_extent_offset(leaf, fi); + + if (orig_start) { + *orig_start = key.offset - backref_offset; + *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); + *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); + } + + if (btrfs_extent_readonly(root, disk_bytenr)) + goto out; + + num_bytes = min(offset + *len, extent_end) - offset; + if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) { + u64 range_end; + + range_end = round_up(offset + num_bytes, root->sectorsize) - 1; + ret = test_range_bit(io_tree, offset, range_end, + EXTENT_DELALLOC, 0, NULL); + if (ret) { + ret = -EAGAIN; + goto out; + } + } + + btrfs_release_path(path); + + /* + * look for other files referencing this extent, if we + * find any we must cow + */ + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + ret = 0; + goto out; + } + + ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode), + key.offset - backref_offset, disk_bytenr); + btrfs_end_transaction(trans, root); + if (ret) { + ret = 0; + goto out; + } + + /* + * adjust disk_bytenr and num_bytes to cover just the bytes + * in this extent we are about to write. If there + * are any csums in that range we have to cow in order + * to keep the csums correct + */ + disk_bytenr += backref_offset; + disk_bytenr += offset - key.offset; + if (csum_exist_in_range(root, disk_bytenr, num_bytes)) + goto out; + /* + * all of the above have passed, it is safe to overwrite this extent + * without cow + */ + *len = num_bytes; + ret = 1; +out: + btrfs_free_path(path); + return ret; +} + +bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end) +{ + struct radix_tree_root *root = &inode->i_mapping->page_tree; + int found = false; + void **pagep = NULL; + struct page *page = NULL; + int start_idx; + int end_idx; + + start_idx = start >> PAGE_CACHE_SHIFT; + + /* + * end is the last byte in the last page. end == start is legal + */ + end_idx = end >> PAGE_CACHE_SHIFT; + + rcu_read_lock(); + + /* Most of the code in this while loop is lifted from + * find_get_page. It's been modified to begin searching from a + * page and return just the first page found in that range. If the + * found idx is less than or equal to the end idx then we know that + * a page exists. If no pages are found or if those pages are + * outside of the range then we're fine (yay!) */ + while (page == NULL && + radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) { + page = radix_tree_deref_slot(pagep); + if (unlikely(!page)) + break; + + if (radix_tree_exception(page)) { + if (radix_tree_deref_retry(page)) { + page = NULL; + continue; + } + /* + * Otherwise, shmem/tmpfs must be storing a swap entry + * here as an exceptional entry: so return it without + * attempting to raise page count. + */ + page = NULL; + break; /* TODO: Is this relevant for this use case? */ + } + + if (!page_cache_get_speculative(page)) { + page = NULL; + continue; + } + + /* + * Has the page moved? + * This is part of the lockless pagecache protocol. See + * include/linux/pagemap.h for details. + */ + if (unlikely(page != *pagep)) { + page_cache_release(page); + page = NULL; + } + } + + if (page) { + if (page->index <= end_idx) + found = true; + page_cache_release(page); + } + + rcu_read_unlock(); + return found; +} + +static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, + struct extent_state **cached_state, int writing) +{ + struct btrfs_ordered_extent *ordered; + int ret = 0; + + while (1) { + lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, + 0, cached_state); + /* + * We're concerned with the entire range that we're going to be + * doing DIO to, so we need to make sure theres no ordered + * extents in this range. + */ + ordered = btrfs_lookup_ordered_range(inode, lockstart, + lockend - lockstart + 1); + + /* + * We need to make sure there are no buffered pages in this + * range either, we could have raced between the invalidate in + * generic_file_direct_write and locking the extent. The + * invalidate needs to happen so that reads after a write do not + * get stale data. + */ + if (!ordered && + (!writing || + !btrfs_page_exists_in_range(inode, lockstart, lockend))) + break; + + unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, + cached_state, GFP_NOFS); + + if (ordered) { + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + } else { + /* Screw you mmap */ + ret = btrfs_fdatawrite_range(inode, lockstart, lockend); + if (ret) + break; + ret = filemap_fdatawait_range(inode->i_mapping, + lockstart, + lockend); + if (ret) + break; + + /* + * If we found a page that couldn't be invalidated just + * fall back to buffered. + */ + ret = invalidate_inode_pages2_range(inode->i_mapping, + lockstart >> PAGE_CACHE_SHIFT, + lockend >> PAGE_CACHE_SHIFT); + if (ret) + break; + } + + cond_resched(); + } + + return ret; +} + +static struct extent_map *create_pinned_em(struct inode *inode, u64 start, + u64 len, u64 orig_start, + u64 block_start, u64 block_len, + u64 orig_block_len, u64 ram_bytes, + int type) +{ + struct extent_map_tree *em_tree; + struct extent_map *em; + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret; + + em_tree = &BTRFS_I(inode)->extent_tree; + em = alloc_extent_map(); + if (!em) + return ERR_PTR(-ENOMEM); + + em->start = start; + em->orig_start = orig_start; + em->mod_start = start; + em->mod_len = len; + em->len = len; + em->block_len = block_len; + em->block_start = block_start; + em->bdev = root->fs_info->fs_devices->latest_bdev; + em->orig_block_len = orig_block_len; + em->ram_bytes = ram_bytes; + em->generation = -1; + set_bit(EXTENT_FLAG_PINNED, &em->flags); + if (type == BTRFS_ORDERED_PREALLOC) + set_bit(EXTENT_FLAG_FILLING, &em->flags); + + do { + btrfs_drop_extent_cache(inode, em->start, + em->start + em->len - 1, 0); + write_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em, 1); + write_unlock(&em_tree->lock); + } while (ret == -EEXIST); + + if (ret) { + free_extent_map(em); + return ERR_PTR(ret); + } + + return em; +} + + +static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int create) +{ + struct extent_map *em; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_state *cached_state = NULL; + u64 start = iblock << inode->i_blkbits; + u64 lockstart, lockend; + u64 len = bh_result->b_size; + u64 *outstanding_extents = NULL; + int unlock_bits = EXTENT_LOCKED; + int ret = 0; + + if (create) + unlock_bits |= EXTENT_DIRTY; + else + len = min_t(u64, len, root->sectorsize); + + lockstart = start; + lockend = start + len - 1; + + if (current->journal_info) { + /* + * Need to pull our outstanding extents and set journal_info to NULL so + * that anything that needs to check if there's a transction doesn't get + * confused. + */ + outstanding_extents = current->journal_info; + current->journal_info = NULL; + } + + /* + * If this errors out it's because we couldn't invalidate pagecache for + * this range and we need to fallback to buffered. + */ + if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create)) + return -ENOTBLK; + + em = btrfs_get_extent(inode, NULL, 0, start, len, 0); + if (IS_ERR(em)) { + ret = PTR_ERR(em); + goto unlock_err; + } + + /* + * Ok for INLINE and COMPRESSED extents we need to fallback on buffered + * io. INLINE is special, and we could probably kludge it in here, but + * it's still buffered so for safety lets just fall back to the generic + * buffered path. + * + * For COMPRESSED we _have_ to read the entire extent in so we can + * decompress it, so there will be buffering required no matter what we + * do, so go ahead and fallback to buffered. + * + * We return -ENOTBLK because thats what makes DIO go ahead and go back + * to buffered IO. Don't blame me, this is the price we pay for using + * the generic code. + */ + if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) || + em->block_start == EXTENT_MAP_INLINE) { + free_extent_map(em); + ret = -ENOTBLK; + goto unlock_err; + } + + /* Just a good old fashioned hole, return */ + if (!create && (em->block_start == EXTENT_MAP_HOLE || + test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { + free_extent_map(em); + goto unlock_err; + } + + /* + * We don't allocate a new extent in the following cases + * + * 1) The inode is marked as NODATACOW. In this case we'll just use the + * existing extent. + * 2) The extent is marked as PREALLOC. We're good to go here and can + * just use the extent. + * + */ + if (!create) { + len = min(len, em->len - (start - em->start)); + lockstart = start + len; + goto unlock; + } + + if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || + ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && + em->block_start != EXTENT_MAP_HOLE)) { + int type; + u64 block_start, orig_start, orig_block_len, ram_bytes; + + if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) + type = BTRFS_ORDERED_PREALLOC; + else + type = BTRFS_ORDERED_NOCOW; + len = min(len, em->len - (start - em->start)); + block_start = em->block_start + (start - em->start); + + if (can_nocow_extent(inode, start, &len, &orig_start, + &orig_block_len, &ram_bytes) == 1) { + if (type == BTRFS_ORDERED_PREALLOC) { + free_extent_map(em); + em = create_pinned_em(inode, start, len, + orig_start, + block_start, len, + orig_block_len, + ram_bytes, type); + if (IS_ERR(em)) { + ret = PTR_ERR(em); + goto unlock_err; + } + } + + ret = btrfs_add_ordered_extent_dio(inode, start, + block_start, len, len, type); + if (ret) { + free_extent_map(em); + goto unlock_err; + } + goto unlock; + } + } + + /* + * this will cow the extent, reset the len in case we changed + * it above + */ + len = bh_result->b_size; + free_extent_map(em); + em = btrfs_new_extent_direct(inode, start, len); + if (IS_ERR(em)) { + ret = PTR_ERR(em); + goto unlock_err; + } + len = min(len, em->len - (start - em->start)); +unlock: + bh_result->b_blocknr = (em->block_start + (start - em->start)) >> + inode->i_blkbits; + bh_result->b_size = len; + bh_result->b_bdev = em->bdev; + set_buffer_mapped(bh_result); + if (create) { + if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) + set_buffer_new(bh_result); + + /* + * Need to update the i_size under the extent lock so buffered + * readers will get the updated i_size when we unlock. + */ + if (start + len > i_size_read(inode)) + i_size_write(inode, start + len); + + /* + * If we have an outstanding_extents count still set then we're + * within our reservation, otherwise we need to adjust our inode + * counter appropriately. + */ + if (*outstanding_extents) { + (*outstanding_extents)--; + } else { + spin_lock(&BTRFS_I(inode)->lock); + BTRFS_I(inode)->outstanding_extents++; + spin_unlock(&BTRFS_I(inode)->lock); + } + + current->journal_info = outstanding_extents; + btrfs_free_reserved_data_space(inode, len); + } + + /* + * In the case of write we need to clear and unlock the entire range, + * in the case of read we need to unlock only the end area that we + * aren't using if there is any left over space. + */ + if (lockstart < lockend) { + clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, + lockend, unlock_bits, 1, 0, + &cached_state, GFP_NOFS); + } else { + free_extent_state(cached_state); + } + + free_extent_map(em); + + return 0; + +unlock_err: + clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, + unlock_bits, 1, 0, &cached_state, GFP_NOFS); + if (outstanding_extents) + current->journal_info = outstanding_extents; + return ret; +} + +static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio, + int rw, int mirror_num) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret; + + BUG_ON(rw & REQ_WRITE); + + bio_get(bio); + + ret = btrfs_bio_wq_end_io(root->fs_info, bio, + BTRFS_WQ_ENDIO_DIO_REPAIR); + if (ret) + goto err; + + ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); +err: + bio_put(bio); + return ret; +} + +static int btrfs_check_dio_repairable(struct inode *inode, + struct bio *failed_bio, + struct io_failure_record *failrec, + int failed_mirror) +{ + int num_copies; + + num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info, + failrec->logical, failrec->len); + if (num_copies == 1) { + /* + * we only have a single copy of the data, so don't bother with + * all the retry and error correction code that follows. no + * matter what the error is, it is very likely to persist. + */ + pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n", + num_copies, failrec->this_mirror, failed_mirror); + return 0; + } + + failrec->failed_mirror = failed_mirror; + failrec->this_mirror++; + if (failrec->this_mirror == failed_mirror) + failrec->this_mirror++; + + if (failrec->this_mirror > num_copies) { + pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n", + num_copies, failrec->this_mirror, failed_mirror); + return 0; + } + + return 1; +} + +static int dio_read_error(struct inode *inode, struct bio *failed_bio, + struct page *page, u64 start, u64 end, + int failed_mirror, bio_end_io_t *repair_endio, + void *repair_arg) +{ + struct io_failure_record *failrec; + struct bio *bio; + int isector; + int read_mode; + int ret; + + BUG_ON(failed_bio->bi_rw & REQ_WRITE); + + ret = btrfs_get_io_failure_record(inode, start, end, &failrec); + if (ret) + return ret; + + ret = btrfs_check_dio_repairable(inode, failed_bio, failrec, + failed_mirror); + if (!ret) { + free_io_failure(inode, failrec); + return -EIO; + } + + if (failed_bio->bi_vcnt > 1) + read_mode = READ_SYNC | REQ_FAILFAST_DEV; + else + read_mode = READ_SYNC; + + isector = start - btrfs_io_bio(failed_bio)->logical; + isector >>= inode->i_sb->s_blocksize_bits; + bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page, + 0, isector, repair_endio, repair_arg); + if (!bio) { + free_io_failure(inode, failrec); + return -EIO; + } + + btrfs_debug(BTRFS_I(inode)->root->fs_info, + "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n", + read_mode, failrec->this_mirror, failrec->in_validation); + + ret = submit_dio_repair_bio(inode, bio, read_mode, + failrec->this_mirror); + if (ret) { + free_io_failure(inode, failrec); + bio_put(bio); + } + + return ret; +} + +struct btrfs_retry_complete { + struct completion done; + struct inode *inode; + u64 start; + int uptodate; +}; + +static void btrfs_retry_endio_nocsum(struct bio *bio, int err) +{ + struct btrfs_retry_complete *done = bio->bi_private; + struct bio_vec *bvec; + int i; + + if (err) + goto end; + + done->uptodate = 1; + bio_for_each_segment_all(bvec, bio, i) + clean_io_failure(done->inode, done->start, bvec->bv_page, 0); +end: + complete(&done->done); + bio_put(bio); +} + +static int __btrfs_correct_data_nocsum(struct inode *inode, + struct btrfs_io_bio *io_bio) +{ + struct bio_vec *bvec; + struct btrfs_retry_complete done; + u64 start; + int i; + int ret; + + start = io_bio->logical; + done.inode = inode; + + bio_for_each_segment_all(bvec, &io_bio->bio, i) { +try_again: + done.uptodate = 0; + done.start = start; + init_completion(&done.done); + + ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start, + start + bvec->bv_len - 1, + io_bio->mirror_num, + btrfs_retry_endio_nocsum, &done); + if (ret) + return ret; + + wait_for_completion(&done.done); + + if (!done.uptodate) { + /* We might have another mirror, so try again */ + goto try_again; + } + + start += bvec->bv_len; + } + + return 0; +} + +static void btrfs_retry_endio(struct bio *bio, int err) +{ + struct btrfs_retry_complete *done = bio->bi_private; + struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); + struct bio_vec *bvec; + int uptodate; + int ret; + int i; + + if (err) + goto end; + + uptodate = 1; + bio_for_each_segment_all(bvec, bio, i) { + ret = __readpage_endio_check(done->inode, io_bio, i, + bvec->bv_page, 0, + done->start, bvec->bv_len); + if (!ret) + clean_io_failure(done->inode, done->start, + bvec->bv_page, 0); + else + uptodate = 0; + } + + done->uptodate = uptodate; +end: + complete(&done->done); + bio_put(bio); +} + +static int __btrfs_subio_endio_read(struct inode *inode, + struct btrfs_io_bio *io_bio, int err) +{ + struct bio_vec *bvec; + struct btrfs_retry_complete done; + u64 start; + u64 offset = 0; + int i; + int ret; + + err = 0; + start = io_bio->logical; + done.inode = inode; + + bio_for_each_segment_all(bvec, &io_bio->bio, i) { + ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page, + 0, start, bvec->bv_len); + if (likely(!ret)) + goto next; +try_again: + done.uptodate = 0; + done.start = start; + init_completion(&done.done); + + ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start, + start + bvec->bv_len - 1, + io_bio->mirror_num, + btrfs_retry_endio, &done); + if (ret) { + err = ret; + goto next; + } + + wait_for_completion(&done.done); + + if (!done.uptodate) { + /* We might have another mirror, so try again */ + goto try_again; + } +next: + offset += bvec->bv_len; + start += bvec->bv_len; + } + + return err; +} + +static int btrfs_subio_endio_read(struct inode *inode, + struct btrfs_io_bio *io_bio, int err) +{ + bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; + + if (skip_csum) { + if (unlikely(err)) + return __btrfs_correct_data_nocsum(inode, io_bio); + else + return 0; + } else { + return __btrfs_subio_endio_read(inode, io_bio, err); + } +} + +static void btrfs_endio_direct_read(struct bio *bio, int err) +{ + struct btrfs_dio_private *dip = bio->bi_private; + struct inode *inode = dip->inode; + struct bio *dio_bio; + struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); + + if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED) + err = btrfs_subio_endio_read(inode, io_bio, err); + + unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset, + dip->logical_offset + dip->bytes - 1); + dio_bio = dip->dio_bio; + + kfree(dip); + + /* If we had a csum failure make sure to clear the uptodate flag */ + if (err) + clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); + dio_end_io(dio_bio, err); + + if (io_bio->end_io) + io_bio->end_io(io_bio, err); + bio_put(bio); +} + +static void btrfs_endio_direct_write(struct bio *bio, int err) +{ + struct btrfs_dio_private *dip = bio->bi_private; + struct inode *inode = dip->inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_ordered_extent *ordered = NULL; + u64 ordered_offset = dip->logical_offset; + u64 ordered_bytes = dip->bytes; + struct bio *dio_bio; + int ret; + + if (err) + goto out_done; +again: + ret = btrfs_dec_test_first_ordered_pending(inode, &ordered, + &ordered_offset, + ordered_bytes, !err); + if (!ret) + goto out_test; + + btrfs_init_work(&ordered->work, btrfs_endio_write_helper, + finish_ordered_fn, NULL, NULL); + btrfs_queue_work(root->fs_info->endio_write_workers, + &ordered->work); +out_test: + /* + * our bio might span multiple ordered extents. If we haven't + * completed the accounting for the whole dio, go back and try again + */ + if (ordered_offset < dip->logical_offset + dip->bytes) { + ordered_bytes = dip->logical_offset + dip->bytes - + ordered_offset; + ordered = NULL; + goto again; + } +out_done: + dio_bio = dip->dio_bio; + + kfree(dip); + + /* If we had an error make sure to clear the uptodate flag */ + if (err) + clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); + dio_end_io(dio_bio, err); + bio_put(bio); +} + +static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw, + struct bio *bio, int mirror_num, + unsigned long bio_flags, u64 offset) +{ + int ret; + struct btrfs_root *root = BTRFS_I(inode)->root; + ret = btrfs_csum_one_bio(root, inode, bio, offset, 1); + BUG_ON(ret); /* -ENOMEM */ + return 0; +} + +static void btrfs_end_dio_bio(struct bio *bio, int err) +{ + struct btrfs_dio_private *dip = bio->bi_private; + + if (err) + btrfs_warn(BTRFS_I(dip->inode)->root->fs_info, + "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d", + btrfs_ino(dip->inode), bio->bi_rw, + (unsigned long long)bio->bi_iter.bi_sector, + bio->bi_iter.bi_size, err); + + if (dip->subio_endio) + err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err); + + if (err) { + dip->errors = 1; + + /* + * before atomic variable goto zero, we must make sure + * dip->errors is perceived to be set. + */ + smp_mb__before_atomic(); + } + + /* if there are more bios still pending for this dio, just exit */ + if (!atomic_dec_and_test(&dip->pending_bios)) + goto out; + + if (dip->errors) { + bio_io_error(dip->orig_bio); + } else { + set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags); + bio_endio(dip->orig_bio, 0); + } +out: + bio_put(bio); +} + +static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev, + u64 first_sector, gfp_t gfp_flags) +{ + int nr_vecs = bio_get_nr_vecs(bdev); + return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags); +} + +static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root, + struct inode *inode, + struct btrfs_dio_private *dip, + struct bio *bio, + u64 file_offset) +{ + struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); + struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio); + int ret; + + /* + * We load all the csum data we need when we submit + * the first bio to reduce the csum tree search and + * contention. + */ + if (dip->logical_offset == file_offset) { + ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio, + file_offset); + if (ret) + return ret; + } + + if (bio == dip->orig_bio) + return 0; + + file_offset -= dip->logical_offset; + file_offset >>= inode->i_sb->s_blocksize_bits; + io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset); + + return 0; +} + +static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, + int rw, u64 file_offset, int skip_sum, + int async_submit) +{ + struct btrfs_dio_private *dip = bio->bi_private; + int write = rw & REQ_WRITE; + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret; + + if (async_submit) + async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers); + + bio_get(bio); + + if (!write) { + ret = btrfs_bio_wq_end_io(root->fs_info, bio, + BTRFS_WQ_ENDIO_DATA); + if (ret) + goto err; + } + + if (skip_sum) + goto map; + + if (write && async_submit) { + ret = btrfs_wq_submit_bio(root->fs_info, + inode, rw, bio, 0, 0, + file_offset, + __btrfs_submit_bio_start_direct_io, + __btrfs_submit_bio_done); + goto err; + } else if (write) { + /* + * If we aren't doing async submit, calculate the csum of the + * bio now. + */ + ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1); + if (ret) + goto err; + } else { + ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio, + file_offset); + if (ret) + goto err; + } +map: + ret = btrfs_map_bio(root, rw, bio, 0, async_submit); +err: + bio_put(bio); + return ret; +} + +static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip, + int skip_sum) +{ + struct inode *inode = dip->inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct bio *bio; + struct bio *orig_bio = dip->orig_bio; + struct bio_vec *bvec = orig_bio->bi_io_vec; + u64 start_sector = orig_bio->bi_iter.bi_sector; + u64 file_offset = dip->logical_offset; + u64 submit_len = 0; + u64 map_length; + int nr_pages = 0; + int ret; + int async_submit = 0; + + map_length = orig_bio->bi_iter.bi_size; + ret = btrfs_map_block(root->fs_info, rw, start_sector << 9, + &map_length, NULL, 0); + if (ret) + return -EIO; + + if (map_length >= orig_bio->bi_iter.bi_size) { + bio = orig_bio; + dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED; + goto submit; + } + + /* async crcs make it difficult to collect full stripe writes. */ + if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK) + async_submit = 0; + else + async_submit = 1; + + bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); + if (!bio) + return -ENOMEM; + + bio->bi_private = dip; + bio->bi_end_io = btrfs_end_dio_bio; + btrfs_io_bio(bio)->logical = file_offset; + atomic_inc(&dip->pending_bios); + + while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) { + if (map_length < submit_len + bvec->bv_len || + bio_add_page(bio, bvec->bv_page, bvec->bv_len, + bvec->bv_offset) < bvec->bv_len) { + /* + * inc the count before we submit the bio so + * we know the end IO handler won't happen before + * we inc the count. Otherwise, the dip might get freed + * before we're done setting it up + */ + atomic_inc(&dip->pending_bios); + ret = __btrfs_submit_dio_bio(bio, inode, rw, + file_offset, skip_sum, + async_submit); + if (ret) { + bio_put(bio); + atomic_dec(&dip->pending_bios); + goto out_err; + } + + start_sector += submit_len >> 9; + file_offset += submit_len; + + submit_len = 0; + nr_pages = 0; + + bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, + start_sector, GFP_NOFS); + if (!bio) + goto out_err; + bio->bi_private = dip; + bio->bi_end_io = btrfs_end_dio_bio; + btrfs_io_bio(bio)->logical = file_offset; + + map_length = orig_bio->bi_iter.bi_size; + ret = btrfs_map_block(root->fs_info, rw, + start_sector << 9, + &map_length, NULL, 0); + if (ret) { + bio_put(bio); + goto out_err; + } + } else { + submit_len += bvec->bv_len; + nr_pages++; + bvec++; + } + } + +submit: + ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum, + async_submit); + if (!ret) + return 0; + + bio_put(bio); +out_err: + dip->errors = 1; + /* + * before atomic variable goto zero, we must + * make sure dip->errors is perceived to be set. + */ + smp_mb__before_atomic(); + if (atomic_dec_and_test(&dip->pending_bios)) + bio_io_error(dip->orig_bio); + + /* bio_end_io() will handle error, so we needn't return it */ + return 0; +} + +static void btrfs_submit_direct(int rw, struct bio *dio_bio, + struct inode *inode, loff_t file_offset) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_dio_private *dip; + struct bio *io_bio; + struct btrfs_io_bio *btrfs_bio; + int skip_sum; + int write = rw & REQ_WRITE; + int ret = 0; + + skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; + + io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS); + if (!io_bio) { + ret = -ENOMEM; + goto free_ordered; + } + + dip = kzalloc(sizeof(*dip), GFP_NOFS); + if (!dip) { + ret = -ENOMEM; + goto free_io_bio; + } + + dip->private = dio_bio->bi_private; + dip->inode = inode; + dip->logical_offset = file_offset; + dip->bytes = dio_bio->bi_iter.bi_size; + dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9; + io_bio->bi_private = dip; + dip->orig_bio = io_bio; + dip->dio_bio = dio_bio; + atomic_set(&dip->pending_bios, 0); + btrfs_bio = btrfs_io_bio(io_bio); + btrfs_bio->logical = file_offset; + + if (write) { + io_bio->bi_end_io = btrfs_endio_direct_write; + } else { + io_bio->bi_end_io = btrfs_endio_direct_read; + dip->subio_endio = btrfs_subio_endio_read; + } + + ret = btrfs_submit_direct_hook(rw, dip, skip_sum); + if (!ret) + return; + + if (btrfs_bio->end_io) + btrfs_bio->end_io(btrfs_bio, ret); +free_io_bio: + bio_put(io_bio); + +free_ordered: + /* + * If this is a write, we need to clean up the reserved space and kill + * the ordered extent. + */ + if (write) { + struct btrfs_ordered_extent *ordered; + ordered = btrfs_lookup_ordered_extent(inode, file_offset); + if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) && + !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) + btrfs_free_reserved_extent(root, ordered->start, + ordered->disk_len, 1); + btrfs_put_ordered_extent(ordered); + btrfs_put_ordered_extent(ordered); + } + bio_endio(dio_bio, ret); +} + +static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb, + const struct iov_iter *iter, loff_t offset) +{ + int seg; + int i; + unsigned blocksize_mask = root->sectorsize - 1; + ssize_t retval = -EINVAL; + + if (offset & blocksize_mask) + goto out; + + if (iov_iter_alignment(iter) & blocksize_mask) + goto out; + + /* If this is a write we don't need to check anymore */ + if (iov_iter_rw(iter) == WRITE) + return 0; + /* + * Check to make sure we don't have duplicate iov_base's in this + * iovec, if so return EINVAL, otherwise we'll get csum errors + * when reading back. + */ + for (seg = 0; seg < iter->nr_segs; seg++) { + for (i = seg + 1; i < iter->nr_segs; i++) { + if (iter->iov[seg].iov_base == iter->iov[i].iov_base) + goto out; + } + } + retval = 0; +out: + return retval; +} + +static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, + loff_t offset) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file->f_mapping->host; + u64 outstanding_extents = 0; + size_t count = 0; + int flags = 0; + bool wakeup = true; + bool relock = false; + ssize_t ret; + + if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset)) + return 0; + + inode_dio_begin(inode); + smp_mb__after_atomic(); + + /* + * The generic stuff only does filemap_write_and_wait_range, which + * isn't enough if we've written compressed pages to this area, so + * we need to flush the dirty pages again to make absolutely sure + * that any outstanding dirty pages are on disk. + */ + count = iov_iter_count(iter); + if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, + &BTRFS_I(inode)->runtime_flags)) + filemap_fdatawrite_range(inode->i_mapping, offset, + offset + count - 1); + + if (iov_iter_rw(iter) == WRITE) { + /* + * If the write DIO is beyond the EOF, we need update + * the isize, but it is protected by i_mutex. So we can + * not unlock the i_mutex at this case. + */ + if (offset + count <= inode->i_size) { + mutex_unlock(&inode->i_mutex); + relock = true; + } + ret = btrfs_delalloc_reserve_space(inode, count); + if (ret) + goto out; + outstanding_extents = div64_u64(count + + BTRFS_MAX_EXTENT_SIZE - 1, + BTRFS_MAX_EXTENT_SIZE); + + /* + * We need to know how many extents we reserved so that we can + * do the accounting properly if we go over the number we + * originally calculated. Abuse current->journal_info for this. + */ + current->journal_info = &outstanding_extents; + } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK, + &BTRFS_I(inode)->runtime_flags)) { + inode_dio_end(inode); + flags = DIO_LOCKING | DIO_SKIP_HOLES; + wakeup = false; + } + + ret = __blockdev_direct_IO(iocb, inode, + BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev, + iter, offset, btrfs_get_blocks_direct, NULL, + btrfs_submit_direct, flags); + if (iov_iter_rw(iter) == WRITE) { + current->journal_info = NULL; + if (ret < 0 && ret != -EIOCBQUEUED) + btrfs_delalloc_release_space(inode, count); + else if (ret >= 0 && (size_t)ret < count) + btrfs_delalloc_release_space(inode, + count - (size_t)ret); + } +out: + if (wakeup) + inode_dio_end(inode); + if (relock) + mutex_lock(&inode->i_mutex); + + return ret; +} + +#define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC) + +static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, + __u64 start, __u64 len) +{ + int ret; + + ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS); + if (ret) + return ret; + + return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap); +} + +int btrfs_readpage(struct file *file, struct page *page) +{ + struct extent_io_tree *tree; + tree = &BTRFS_I(page->mapping->host)->io_tree; + return extent_read_full_page(tree, page, btrfs_get_extent, 0); +} + +static int btrfs_writepage(struct page *page, struct writeback_control *wbc) +{ + struct extent_io_tree *tree; + + + if (current->flags & PF_MEMALLOC) { + redirty_page_for_writepage(wbc, page); + unlock_page(page); + return 0; + } + tree = &BTRFS_I(page->mapping->host)->io_tree; + return extent_write_full_page(tree, page, btrfs_get_extent, wbc); +} + +static int btrfs_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + struct extent_io_tree *tree; + + tree = &BTRFS_I(mapping->host)->io_tree; + return extent_writepages(tree, mapping, btrfs_get_extent, wbc); +} + +static int +btrfs_readpages(struct file *file, struct address_space *mapping, + struct list_head *pages, unsigned nr_pages) +{ + struct extent_io_tree *tree; + tree = &BTRFS_I(mapping->host)->io_tree; + return extent_readpages(tree, mapping, pages, nr_pages, + btrfs_get_extent); +} +static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) +{ + struct extent_io_tree *tree; + struct extent_map_tree *map; + int ret; + + tree = &BTRFS_I(page->mapping->host)->io_tree; + map = &BTRFS_I(page->mapping->host)->extent_tree; + ret = try_release_extent_mapping(map, tree, page, gfp_flags); + if (ret == 1) { + ClearPagePrivate(page); + set_page_private(page, 0); + page_cache_release(page); + } + return ret; +} + +static int btrfs_releasepage(struct page *page, gfp_t gfp_flags) +{ + if (PageWriteback(page) || PageDirty(page)) + return 0; + return __btrfs_releasepage(page, gfp_flags & GFP_NOFS); +} + +static void btrfs_invalidatepage(struct page *page, unsigned int offset, + unsigned int length) +{ + struct inode *inode = page->mapping->host; + struct extent_io_tree *tree; + struct btrfs_ordered_extent *ordered; + struct extent_state *cached_state = NULL; + u64 page_start = page_offset(page); + u64 page_end = page_start + PAGE_CACHE_SIZE - 1; + int inode_evicting = inode->i_state & I_FREEING; + + /* + * we have the page locked, so new writeback can't start, + * and the dirty bit won't be cleared while we are here. + * + * Wait for IO on this page so that we can safely clear + * the PagePrivate2 bit and do ordered accounting + */ + wait_on_page_writeback(page); + + tree = &BTRFS_I(inode)->io_tree; + if (offset) { + btrfs_releasepage(page, GFP_NOFS); + return; + } + + if (!inode_evicting) + lock_extent_bits(tree, page_start, page_end, 0, &cached_state); + ordered = btrfs_lookup_ordered_extent(inode, page_start); + if (ordered) { + /* + * IO on this page will never be started, so we need + * to account for any ordered extents now + */ + if (!inode_evicting) + clear_extent_bit(tree, page_start, page_end, + EXTENT_DIRTY | EXTENT_DELALLOC | + EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | + EXTENT_DEFRAG, 1, 0, &cached_state, + GFP_NOFS); + /* + * whoever cleared the private bit is responsible + * for the finish_ordered_io + */ + if (TestClearPagePrivate2(page)) { + struct btrfs_ordered_inode_tree *tree; + u64 new_len; + + tree = &BTRFS_I(inode)->ordered_tree; + + spin_lock_irq(&tree->lock); + set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags); + new_len = page_start - ordered->file_offset; + if (new_len < ordered->truncated_len) + ordered->truncated_len = new_len; + spin_unlock_irq(&tree->lock); + + if (btrfs_dec_test_ordered_pending(inode, &ordered, + page_start, + PAGE_CACHE_SIZE, 1)) + btrfs_finish_ordered_io(ordered); + } + btrfs_put_ordered_extent(ordered); + if (!inode_evicting) { + cached_state = NULL; + lock_extent_bits(tree, page_start, page_end, 0, + &cached_state); + } + } + + if (!inode_evicting) { + clear_extent_bit(tree, page_start, page_end, + EXTENT_LOCKED | EXTENT_DIRTY | + EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | + EXTENT_DEFRAG, 1, 1, + &cached_state, GFP_NOFS); + + __btrfs_releasepage(page, GFP_NOFS); + } + + ClearPageChecked(page); + if (PagePrivate(page)) { + ClearPagePrivate(page); + set_page_private(page, 0); + page_cache_release(page); + } +} + +/* + * btrfs_page_mkwrite() is not allowed to change the file size as it gets + * called from a page fault handler when a page is first dirtied. Hence we must + * be careful to check for EOF conditions here. We set the page up correctly + * for a written page which means we get ENOSPC checking when writing into + * holes and correct delalloc and unwritten extent mapping on filesystems that + * support these features. + * + * We are not allowed to take the i_mutex here so we have to play games to + * protect against truncate races as the page could now be beyond EOF. Because + * vmtruncate() writes the inode size before removing pages, once we have the + * page lock we can determine safely if the page is beyond EOF. If it is not + * beyond EOF, then the page is guaranteed safe against truncation until we + * unlock the page. + */ +int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct page *page = vmf->page; + struct inode *inode = file_inode(vma->vm_file); + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_ordered_extent *ordered; + struct extent_state *cached_state = NULL; + char *kaddr; + unsigned long zero_start; + loff_t size; + int ret; + int reserved = 0; + u64 page_start; + u64 page_end; + + sb_start_pagefault(inode->i_sb); + ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); + if (!ret) { + ret = file_update_time(vma->vm_file); + reserved = 1; + } + if (ret) { + if (ret == -ENOMEM) + ret = VM_FAULT_OOM; + else /* -ENOSPC, -EIO, etc */ + ret = VM_FAULT_SIGBUS; + if (reserved) + goto out; + goto out_noreserve; + } + + ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ +again: + lock_page(page); + size = i_size_read(inode); + page_start = page_offset(page); + page_end = page_start + PAGE_CACHE_SIZE - 1; + + if ((page->mapping != inode->i_mapping) || + (page_start >= size)) { + /* page got truncated out from underneath us */ + goto out_unlock; + } + wait_on_page_writeback(page); + + lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state); + set_page_extent_mapped(page); + + /* + * we can't set the delalloc bits if there are pending ordered + * extents. Drop our locks and wait for them to finish + */ + ordered = btrfs_lookup_ordered_extent(inode, page_start); + if (ordered) { + unlock_extent_cached(io_tree, page_start, page_end, + &cached_state, GFP_NOFS); + unlock_page(page); + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + goto again; + } + + /* + * XXX - page_mkwrite gets called every time the page is dirtied, even + * if it was already dirty, so for space accounting reasons we need to + * clear any delalloc bits for the range we are fixing to save. There + * is probably a better way to do this, but for now keep consistent with + * prepare_pages in the normal write path. + */ + clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, + EXTENT_DIRTY | EXTENT_DELALLOC | + EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, + 0, 0, &cached_state, GFP_NOFS); + + ret = btrfs_set_extent_delalloc(inode, page_start, page_end, + &cached_state); + if (ret) { + unlock_extent_cached(io_tree, page_start, page_end, + &cached_state, GFP_NOFS); + ret = VM_FAULT_SIGBUS; + goto out_unlock; + } + ret = 0; + + /* page is wholly or partially inside EOF */ + if (page_start + PAGE_CACHE_SIZE > size) + zero_start = size & ~PAGE_CACHE_MASK; + else + zero_start = PAGE_CACHE_SIZE; + + if (zero_start != PAGE_CACHE_SIZE) { + kaddr = kmap(page); + memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start); + flush_dcache_page(page); + kunmap(page); + } + ClearPageChecked(page); + set_page_dirty(page); + SetPageUptodate(page); + + BTRFS_I(inode)->last_trans = root->fs_info->generation; + BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; + BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit; + + unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); + +out_unlock: + if (!ret) { + sb_end_pagefault(inode->i_sb); + return VM_FAULT_LOCKED; + } + unlock_page(page); +out: + btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); +out_noreserve: + sb_end_pagefault(inode->i_sb); + return ret; +} + +static int btrfs_truncate(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_block_rsv *rsv; + int ret = 0; + int err = 0; + struct btrfs_trans_handle *trans; + u64 mask = root->sectorsize - 1; + u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); + + ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask), + (u64)-1); + if (ret) + return ret; + + /* + * Yes ladies and gentelment, this is indeed ugly. The fact is we have + * 3 things going on here + * + * 1) We need to reserve space for our orphan item and the space to + * delete our orphan item. Lord knows we don't want to have a dangling + * orphan item because we didn't reserve space to remove it. + * + * 2) We need to reserve space to update our inode. + * + * 3) We need to have something to cache all the space that is going to + * be free'd up by the truncate operation, but also have some slack + * space reserved in case it uses space during the truncate (thank you + * very much snapshotting). + * + * And we need these to all be seperate. The fact is we can use alot of + * space doing the truncate, and we have no earthly idea how much space + * we will use, so we need the truncate reservation to be seperate so it + * doesn't end up using space reserved for updating the inode or + * removing the orphan item. We also need to be able to stop the + * transaction and start a new one, which means we need to be able to + * update the inode several times, and we have no idea of knowing how + * many times that will be, so we can't just reserve 1 item for the + * entirety of the opration, so that has to be done seperately as well. + * Then there is the orphan item, which does indeed need to be held on + * to for the whole operation, and we need nobody to touch this reserved + * space except the orphan code. + * + * So that leaves us with + * + * 1) root->orphan_block_rsv - for the orphan deletion. + * 2) rsv - for the truncate reservation, which we will steal from the + * transaction reservation. + * 3) fs_info->trans_block_rsv - this will have 1 items worth left for + * updating the inode. + */ + rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); + if (!rsv) + return -ENOMEM; + rsv->size = min_size; + rsv->failfast = 1; + + /* + * 1 for the truncate slack space + * 1 for updating the inode. + */ + trans = btrfs_start_transaction(root, 2); + if (IS_ERR(trans)) { + err = PTR_ERR(trans); + goto out; + } + + /* Migrate the slack space for the truncate to our reserve */ + ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv, + min_size); + BUG_ON(ret); + + /* + * So if we truncate and then write and fsync we normally would just + * write the extents that changed, which is a problem if we need to + * first truncate that entire inode. So set this flag so we write out + * all of the extents in the inode to the sync log so we're completely + * safe. + */ + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); + trans->block_rsv = rsv; + + while (1) { + ret = btrfs_truncate_inode_items(trans, root, inode, + inode->i_size, + BTRFS_EXTENT_DATA_KEY); + if (ret != -ENOSPC && ret != -EAGAIN) { + err = ret; + break; + } + + trans->block_rsv = &root->fs_info->trans_block_rsv; + ret = btrfs_update_inode(trans, root, inode); + if (ret) { + err = ret; + break; + } + + btrfs_end_transaction(trans, root); + btrfs_btree_balance_dirty(root); + + trans = btrfs_start_transaction(root, 2); + if (IS_ERR(trans)) { + ret = err = PTR_ERR(trans); + trans = NULL; + break; + } + + ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, + rsv, min_size); + BUG_ON(ret); /* shouldn't happen */ + trans->block_rsv = rsv; + } + + if (ret == 0 && inode->i_nlink > 0) { + trans->block_rsv = root->orphan_block_rsv; + ret = btrfs_orphan_del(trans, inode); + if (ret) + err = ret; + } + + if (trans) { + trans->block_rsv = &root->fs_info->trans_block_rsv; + ret = btrfs_update_inode(trans, root, inode); + if (ret && !err) + err = ret; + + ret = btrfs_end_transaction(trans, root); + btrfs_btree_balance_dirty(root); + } + +out: + btrfs_free_block_rsv(root, rsv); + + if (ret && !err) + err = ret; + + return err; +} + +/* + * create a new subvolume directory/inode (helper for the ioctl). + */ +int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, + struct btrfs_root *new_root, + struct btrfs_root *parent_root, + u64 new_dirid) +{ + struct inode *inode; + int err; + u64 index = 0; + + inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, + new_dirid, new_dirid, + S_IFDIR | (~current_umask() & S_IRWXUGO), + &index); + if (IS_ERR(inode)) + return PTR_ERR(inode); + inode->i_op = &btrfs_dir_inode_operations; + inode->i_fop = &btrfs_dir_file_operations; + + set_nlink(inode, 1); + btrfs_i_size_write(inode, 0); + unlock_new_inode(inode); + + err = btrfs_subvol_inherit_props(trans, new_root, parent_root); + if (err) + btrfs_err(new_root->fs_info, + "error inheriting subvolume %llu properties: %d", + new_root->root_key.objectid, err); + + err = btrfs_update_inode(trans, new_root, inode); + + iput(inode); + return err; +} + +struct inode *btrfs_alloc_inode(struct super_block *sb) +{ + struct btrfs_inode *ei; + struct inode *inode; + + ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS); + if (!ei) + return NULL; + + ei->root = NULL; + ei->generation = 0; + ei->last_trans = 0; + ei->last_sub_trans = 0; + ei->logged_trans = 0; + ei->delalloc_bytes = 0; + ei->defrag_bytes = 0; + ei->disk_i_size = 0; + ei->flags = 0; + ei->csum_bytes = 0; + ei->index_cnt = (u64)-1; + ei->dir_index = 0; + ei->last_unlink_trans = 0; + ei->last_log_commit = 0; + + spin_lock_init(&ei->lock); + ei->outstanding_extents = 0; + ei->reserved_extents = 0; + + ei->runtime_flags = 0; + ei->force_compress = BTRFS_COMPRESS_NONE; + + ei->delayed_node = NULL; + + ei->i_otime.tv_sec = 0; + ei->i_otime.tv_nsec = 0; + + inode = &ei->vfs_inode; + extent_map_tree_init(&ei->extent_tree); + extent_io_tree_init(&ei->io_tree, &inode->i_data); + extent_io_tree_init(&ei->io_failure_tree, &inode->i_data); + ei->io_tree.track_uptodate = 1; + ei->io_failure_tree.track_uptodate = 1; + atomic_set(&ei->sync_writers, 0); + mutex_init(&ei->log_mutex); + mutex_init(&ei->delalloc_mutex); + btrfs_ordered_inode_tree_init(&ei->ordered_tree); + INIT_LIST_HEAD(&ei->delalloc_inodes); + RB_CLEAR_NODE(&ei->rb_node); + + return inode; +} + +#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS +void btrfs_test_destroy_inode(struct inode *inode) +{ + btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); + kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); +} +#endif + +static void btrfs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); +} + +void btrfs_destroy_inode(struct inode *inode) +{ + struct btrfs_ordered_extent *ordered; + struct btrfs_root *root = BTRFS_I(inode)->root; + + WARN_ON(!hlist_empty(&inode->i_dentry)); + WARN_ON(inode->i_data.nrpages); + WARN_ON(BTRFS_I(inode)->outstanding_extents); + WARN_ON(BTRFS_I(inode)->reserved_extents); + WARN_ON(BTRFS_I(inode)->delalloc_bytes); + WARN_ON(BTRFS_I(inode)->csum_bytes); + WARN_ON(BTRFS_I(inode)->defrag_bytes); + + /* + * This can happen where we create an inode, but somebody else also + * created the same inode and we need to destroy the one we already + * created. + */ + if (!root) + goto free; + + if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, + &BTRFS_I(inode)->runtime_flags)) { + btrfs_info(root->fs_info, "inode %llu still on the orphan list", + btrfs_ino(inode)); + atomic_dec(&root->orphan_inodes); + } + + while (1) { + ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1); + if (!ordered) + break; + else { + btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup", + ordered->file_offset, ordered->len); + btrfs_remove_ordered_extent(inode, ordered); + btrfs_put_ordered_extent(ordered); + btrfs_put_ordered_extent(ordered); + } + } + inode_tree_del(inode); + btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); +free: + call_rcu(&inode->i_rcu, btrfs_i_callback); +} + +int btrfs_drop_inode(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + + if (root == NULL) + return 1; + + /* the snap/subvol tree is on deleting */ + if (btrfs_root_refs(&root->root_item) == 0) + return 1; + else + return generic_drop_inode(inode); +} + +static void init_once(void *foo) +{ + struct btrfs_inode *ei = (struct btrfs_inode *) foo; + + inode_init_once(&ei->vfs_inode); +} + +void btrfs_destroy_cachep(void) +{ + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); + if (btrfs_inode_cachep) + kmem_cache_destroy(btrfs_inode_cachep); + if (btrfs_trans_handle_cachep) + kmem_cache_destroy(btrfs_trans_handle_cachep); + if (btrfs_transaction_cachep) + kmem_cache_destroy(btrfs_transaction_cachep); + if (btrfs_path_cachep) + kmem_cache_destroy(btrfs_path_cachep); + if (btrfs_free_space_cachep) + kmem_cache_destroy(btrfs_free_space_cachep); + if (btrfs_delalloc_work_cachep) + kmem_cache_destroy(btrfs_delalloc_work_cachep); +} + +int btrfs_init_cachep(void) +{ + btrfs_inode_cachep = kmem_cache_create("btrfs_inode", + sizeof(struct btrfs_inode), 0, + SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once); + if (!btrfs_inode_cachep) + goto fail; + + btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle", + sizeof(struct btrfs_trans_handle), 0, + SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); + if (!btrfs_trans_handle_cachep) + goto fail; + + btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction", + sizeof(struct btrfs_transaction), 0, + SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); + if (!btrfs_transaction_cachep) + goto fail; + + btrfs_path_cachep = kmem_cache_create("btrfs_path", + sizeof(struct btrfs_path), 0, + SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); + if (!btrfs_path_cachep) + goto fail; + + btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space", + sizeof(struct btrfs_free_space), 0, + SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); + if (!btrfs_free_space_cachep) + goto fail; + + btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work", + sizeof(struct btrfs_delalloc_work), 0, + SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, + NULL); + if (!btrfs_delalloc_work_cachep) + goto fail; + + return 0; +fail: + btrfs_destroy_cachep(); + return -ENOMEM; +} + +static int btrfs_getattr(struct vfsmount *mnt, + struct dentry *dentry, struct kstat *stat) +{ + u64 delalloc_bytes; + struct inode *inode = d_inode(dentry); + u32 blocksize = inode->i_sb->s_blocksize; + + generic_fillattr(inode, stat); + stat->dev = BTRFS_I(inode)->root->anon_dev; + stat->blksize = PAGE_CACHE_SIZE; + + spin_lock(&BTRFS_I(inode)->lock); + delalloc_bytes = BTRFS_I(inode)->delalloc_bytes; + spin_unlock(&BTRFS_I(inode)->lock); + stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) + + ALIGN(delalloc_bytes, blocksize)) >> 9; + return 0; +} + +static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(old_dir)->root; + struct btrfs_root *dest = BTRFS_I(new_dir)->root; + struct inode *new_inode = d_inode(new_dentry); + struct inode *old_inode = d_inode(old_dentry); + struct timespec ctime = CURRENT_TIME; + u64 index = 0; + u64 root_objectid; + int ret; + u64 old_ino = btrfs_ino(old_inode); + + if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) + return -EPERM; + + /* we only allow rename subvolume link between subvolumes */ + if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) + return -EXDEV; + + if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID || + (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID)) + return -ENOTEMPTY; + + if (S_ISDIR(old_inode->i_mode) && new_inode && + new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) + return -ENOTEMPTY; + + + /* check for collisions, even if the name isn't there */ + ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino, + new_dentry->d_name.name, + new_dentry->d_name.len); + + if (ret) { + if (ret == -EEXIST) { + /* we shouldn't get + * eexist without a new_inode */ + if (WARN_ON(!new_inode)) { + return ret; + } + } else { + /* maybe -EOVERFLOW */ + return ret; + } + } + ret = 0; + + /* + * we're using rename to replace one file with another. Start IO on it + * now so we don't add too much work to the end of the transaction + */ + if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size) + filemap_flush(old_inode->i_mapping); + + /* close the racy window with snapshot create/destroy ioctl */ + if (old_ino == BTRFS_FIRST_FREE_OBJECTID) + down_read(&root->fs_info->subvol_sem); + /* + * We want to reserve the absolute worst case amount of items. So if + * both inodes are subvols and we need to unlink them then that would + * require 4 item modifications, but if they are both normal inodes it + * would require 5 item modifications, so we'll assume their normal + * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items + * should cover the worst case number of items we'll modify. + */ + trans = btrfs_start_transaction(root, 11); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_notrans; + } + + if (dest != root) + btrfs_record_root_in_trans(trans, dest); + + ret = btrfs_set_inode_index(new_dir, &index); + if (ret) + goto out_fail; + + BTRFS_I(old_inode)->dir_index = 0ULL; + if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { + /* force full log commit if subvolume involved. */ + btrfs_set_log_full_commit(root->fs_info, trans); + } else { + ret = btrfs_insert_inode_ref(trans, dest, + new_dentry->d_name.name, + new_dentry->d_name.len, + old_ino, + btrfs_ino(new_dir), index); + if (ret) + goto out_fail; + /* + * this is an ugly little race, but the rename is required + * to make sure that if we crash, the inode is either at the + * old name or the new one. pinning the log transaction lets + * us make sure we don't allow a log commit to come in after + * we unlink the name but before we add the new name back in. + */ + btrfs_pin_log_trans(root); + } + + inode_inc_iversion(old_dir); + inode_inc_iversion(new_dir); + inode_inc_iversion(old_inode); + old_dir->i_ctime = old_dir->i_mtime = ctime; + new_dir->i_ctime = new_dir->i_mtime = ctime; + old_inode->i_ctime = ctime; + + if (old_dentry->d_parent != new_dentry->d_parent) + btrfs_record_unlink_dir(trans, old_dir, old_inode, 1); + + if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { + root_objectid = BTRFS_I(old_inode)->root->root_key.objectid; + ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid, + old_dentry->d_name.name, + old_dentry->d_name.len); + } else { + ret = __btrfs_unlink_inode(trans, root, old_dir, + d_inode(old_dentry), + old_dentry->d_name.name, + old_dentry->d_name.len); + if (!ret) + ret = btrfs_update_inode(trans, root, old_inode); + } + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out_fail; + } + + if (new_inode) { + inode_inc_iversion(new_inode); + new_inode->i_ctime = CURRENT_TIME; + if (unlikely(btrfs_ino(new_inode) == + BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { + root_objectid = BTRFS_I(new_inode)->location.objectid; + ret = btrfs_unlink_subvol(trans, dest, new_dir, + root_objectid, + new_dentry->d_name.name, + new_dentry->d_name.len); + BUG_ON(new_inode->i_nlink == 0); + } else { + ret = btrfs_unlink_inode(trans, dest, new_dir, + d_inode(new_dentry), + new_dentry->d_name.name, + new_dentry->d_name.len); + } + if (!ret && new_inode->i_nlink == 0) + ret = btrfs_orphan_add(trans, d_inode(new_dentry)); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out_fail; + } + } + + ret = btrfs_add_link(trans, new_dir, old_inode, + new_dentry->d_name.name, + new_dentry->d_name.len, 0, index); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out_fail; + } + + if (old_inode->i_nlink == 1) + BTRFS_I(old_inode)->dir_index = index; + + if (old_ino != BTRFS_FIRST_FREE_OBJECTID) { + struct dentry *parent = new_dentry->d_parent; + btrfs_log_new_name(trans, old_inode, old_dir, parent); + btrfs_end_log_trans(root); + } +out_fail: + btrfs_end_transaction(trans, root); +out_notrans: + if (old_ino == BTRFS_FIRST_FREE_OBJECTID) + up_read(&root->fs_info->subvol_sem); + + return ret; +} + +static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + if (flags & ~RENAME_NOREPLACE) + return -EINVAL; + + return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry); +} + +static void btrfs_run_delalloc_work(struct btrfs_work *work) +{ + struct btrfs_delalloc_work *delalloc_work; + struct inode *inode; + + delalloc_work = container_of(work, struct btrfs_delalloc_work, + work); + inode = delalloc_work->inode; + if (delalloc_work->wait) { + btrfs_wait_ordered_range(inode, 0, (u64)-1); + } else { + filemap_flush(inode->i_mapping); + if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, + &BTRFS_I(inode)->runtime_flags)) + filemap_flush(inode->i_mapping); + } + + if (delalloc_work->delay_iput) + btrfs_add_delayed_iput(inode); + else + iput(inode); + complete(&delalloc_work->completion); +} + +struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode, + int wait, int delay_iput) +{ + struct btrfs_delalloc_work *work; + + work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS); + if (!work) + return NULL; + + init_completion(&work->completion); + INIT_LIST_HEAD(&work->list); + work->inode = inode; + work->wait = wait; + work->delay_iput = delay_iput; + WARN_ON_ONCE(!inode); + btrfs_init_work(&work->work, btrfs_flush_delalloc_helper, + btrfs_run_delalloc_work, NULL, NULL); + + return work; +} + +void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work) +{ + wait_for_completion(&work->completion); + kmem_cache_free(btrfs_delalloc_work_cachep, work); +} + +/* + * some fairly slow code that needs optimization. This walks the list + * of all the inodes with pending delalloc and forces them to disk. + */ +static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput, + int nr) +{ + struct btrfs_inode *binode; + struct inode *inode; + struct btrfs_delalloc_work *work, *next; + struct list_head works; + struct list_head splice; + int ret = 0; + + INIT_LIST_HEAD(&works); + INIT_LIST_HEAD(&splice); + + mutex_lock(&root->delalloc_mutex); + spin_lock(&root->delalloc_lock); + list_splice_init(&root->delalloc_inodes, &splice); + while (!list_empty(&splice)) { + binode = list_entry(splice.next, struct btrfs_inode, + delalloc_inodes); + + list_move_tail(&binode->delalloc_inodes, + &root->delalloc_inodes); + inode = igrab(&binode->vfs_inode); + if (!inode) { + cond_resched_lock(&root->delalloc_lock); + continue; + } + spin_unlock(&root->delalloc_lock); + + work = btrfs_alloc_delalloc_work(inode, 0, delay_iput); + if (!work) { + if (delay_iput) + btrfs_add_delayed_iput(inode); + else + iput(inode); + ret = -ENOMEM; + goto out; + } + list_add_tail(&work->list, &works); + btrfs_queue_work(root->fs_info->flush_workers, + &work->work); + ret++; + if (nr != -1 && ret >= nr) + goto out; + cond_resched(); + spin_lock(&root->delalloc_lock); + } + spin_unlock(&root->delalloc_lock); + +out: + list_for_each_entry_safe(work, next, &works, list) { + list_del_init(&work->list); + btrfs_wait_and_free_delalloc_work(work); + } + + if (!list_empty_careful(&splice)) { + spin_lock(&root->delalloc_lock); + list_splice_tail(&splice, &root->delalloc_inodes); + spin_unlock(&root->delalloc_lock); + } + mutex_unlock(&root->delalloc_mutex); + return ret; +} + +int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput) +{ + int ret; + + if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) + return -EROFS; + + ret = __start_delalloc_inodes(root, delay_iput, -1); + if (ret > 0) + ret = 0; + /* + * the filemap_flush will queue IO into the worker threads, but + * we have to make sure the IO is actually started and that + * ordered extents get created before we return + */ + atomic_inc(&root->fs_info->async_submit_draining); + while (atomic_read(&root->fs_info->nr_async_submits) || + atomic_read(&root->fs_info->async_delalloc_pages)) { + wait_event(root->fs_info->async_submit_wait, + (atomic_read(&root->fs_info->nr_async_submits) == 0 && + atomic_read(&root->fs_info->async_delalloc_pages) == 0)); + } + atomic_dec(&root->fs_info->async_submit_draining); + return ret; +} + +int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput, + int nr) +{ + struct btrfs_root *root; + struct list_head splice; + int ret; + + if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) + return -EROFS; + + INIT_LIST_HEAD(&splice); + + mutex_lock(&fs_info->delalloc_root_mutex); + spin_lock(&fs_info->delalloc_root_lock); + list_splice_init(&fs_info->delalloc_roots, &splice); + while (!list_empty(&splice) && nr) { + root = list_first_entry(&splice, struct btrfs_root, + delalloc_root); + root = btrfs_grab_fs_root(root); + BUG_ON(!root); + list_move_tail(&root->delalloc_root, + &fs_info->delalloc_roots); + spin_unlock(&fs_info->delalloc_root_lock); + + ret = __start_delalloc_inodes(root, delay_iput, nr); + btrfs_put_fs_root(root); + if (ret < 0) + goto out; + + if (nr != -1) { + nr -= ret; + WARN_ON(nr < 0); + } + spin_lock(&fs_info->delalloc_root_lock); + } + spin_unlock(&fs_info->delalloc_root_lock); + + ret = 0; + atomic_inc(&fs_info->async_submit_draining); + while (atomic_read(&fs_info->nr_async_submits) || + atomic_read(&fs_info->async_delalloc_pages)) { + wait_event(fs_info->async_submit_wait, + (atomic_read(&fs_info->nr_async_submits) == 0 && + atomic_read(&fs_info->async_delalloc_pages) == 0)); + } + atomic_dec(&fs_info->async_submit_draining); +out: + if (!list_empty_careful(&splice)) { + spin_lock(&fs_info->delalloc_root_lock); + list_splice_tail(&splice, &fs_info->delalloc_roots); + spin_unlock(&fs_info->delalloc_root_lock); + } + mutex_unlock(&fs_info->delalloc_root_mutex); + return ret; +} + +static int btrfs_symlink(struct inode *dir, struct dentry *dentry, + const char *symname) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_path *path; + struct btrfs_key key; + struct inode *inode = NULL; + int err; + int drop_inode = 0; + u64 objectid; + u64 index = 0; + int name_len; + int datasize; + unsigned long ptr; + struct btrfs_file_extent_item *ei; + struct extent_buffer *leaf; + + name_len = strlen(symname); + if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) + return -ENAMETOOLONG; + + /* + * 2 items for inode item and ref + * 2 items for dir items + * 1 item for xattr if selinux is on + */ + trans = btrfs_start_transaction(root, 5); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + err = btrfs_find_free_ino(root, &objectid); + if (err) + goto out_unlock; + + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, + dentry->d_name.len, btrfs_ino(dir), objectid, + S_IFLNK|S_IRWXUGO, &index); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_unlock; + } + + /* + * If the active LSM wants to access the inode during + * d_instantiate it needs these. Smack checks to see + * if the filesystem supports xattrs by looking at the + * ops vector. + */ + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; + inode->i_mapping->a_ops = &btrfs_aops; + BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; + + err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); + if (err) + goto out_unlock_inode; + + err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); + if (err) + goto out_unlock_inode; + + path = btrfs_alloc_path(); + if (!path) { + err = -ENOMEM; + goto out_unlock_inode; + } + key.objectid = btrfs_ino(inode); + key.offset = 0; + key.type = BTRFS_EXTENT_DATA_KEY; + datasize = btrfs_file_extent_calc_inline_size(name_len); + err = btrfs_insert_empty_item(trans, root, path, &key, + datasize); + if (err) { + btrfs_free_path(path); + goto out_unlock_inode; + } + leaf = path->nodes[0]; + ei = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + btrfs_set_file_extent_generation(leaf, ei, trans->transid); + btrfs_set_file_extent_type(leaf, ei, + BTRFS_FILE_EXTENT_INLINE); + btrfs_set_file_extent_encryption(leaf, ei, 0); + btrfs_set_file_extent_compression(leaf, ei, 0); + btrfs_set_file_extent_other_encoding(leaf, ei, 0); + btrfs_set_file_extent_ram_bytes(leaf, ei, name_len); + + ptr = btrfs_file_extent_inline_start(ei); + write_extent_buffer(leaf, symname, ptr, name_len); + btrfs_mark_buffer_dirty(leaf); + btrfs_free_path(path); + + inode->i_op = &btrfs_symlink_inode_operations; + inode->i_mapping->a_ops = &btrfs_symlink_aops; + inode_set_bytes(inode, name_len); + btrfs_i_size_write(inode, name_len); + err = btrfs_update_inode(trans, root, inode); + if (err) { + drop_inode = 1; + goto out_unlock_inode; + } + + unlock_new_inode(inode); + d_instantiate(dentry, inode); + +out_unlock: + btrfs_end_transaction(trans, root); + if (drop_inode) { + inode_dec_link_count(inode); + iput(inode); + } + btrfs_btree_balance_dirty(root); + return err; + +out_unlock_inode: + drop_inode = 1; + unlock_new_inode(inode); + goto out_unlock; +} + +static int __btrfs_prealloc_file_range(struct inode *inode, int mode, + u64 start, u64 num_bytes, u64 min_size, + loff_t actual_len, u64 *alloc_hint, + struct btrfs_trans_handle *trans) +{ + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + struct extent_map *em; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_key ins; + u64 cur_offset = start; + u64 i_size; + u64 cur_bytes; + int ret = 0; + bool own_trans = true; + + if (trans) + own_trans = false; + while (num_bytes > 0) { + if (own_trans) { + trans = btrfs_start_transaction(root, 3); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + break; + } + } + + cur_bytes = min(num_bytes, 256ULL * 1024 * 1024); + cur_bytes = max(cur_bytes, min_size); + ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0, + *alloc_hint, &ins, 1, 0); + if (ret) { + if (own_trans) + btrfs_end_transaction(trans, root); + break; + } + + ret = insert_reserved_file_extent(trans, inode, + cur_offset, ins.objectid, + ins.offset, ins.offset, + ins.offset, 0, 0, 0, + BTRFS_FILE_EXTENT_PREALLOC); + if (ret) { + btrfs_free_reserved_extent(root, ins.objectid, + ins.offset, 0); + btrfs_abort_transaction(trans, root, ret); + if (own_trans) + btrfs_end_transaction(trans, root); + break; + } + + btrfs_drop_extent_cache(inode, cur_offset, + cur_offset + ins.offset -1, 0); + + em = alloc_extent_map(); + if (!em) { + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &BTRFS_I(inode)->runtime_flags); + goto next; + } + + em->start = cur_offset; + em->orig_start = cur_offset; + em->len = ins.offset; + em->block_start = ins.objectid; + em->block_len = ins.offset; + em->orig_block_len = ins.offset; + em->ram_bytes = ins.offset; + em->bdev = root->fs_info->fs_devices->latest_bdev; + set_bit(EXTENT_FLAG_PREALLOC, &em->flags); + em->generation = trans->transid; + + while (1) { + write_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em, 1); + write_unlock(&em_tree->lock); + if (ret != -EEXIST) + break; + btrfs_drop_extent_cache(inode, cur_offset, + cur_offset + ins.offset - 1, + 0); + } + free_extent_map(em); +next: + num_bytes -= ins.offset; + cur_offset += ins.offset; + *alloc_hint = ins.objectid + ins.offset; + + inode_inc_iversion(inode); + inode->i_ctime = CURRENT_TIME; + BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC; + if (!(mode & FALLOC_FL_KEEP_SIZE) && + (actual_len > inode->i_size) && + (cur_offset > inode->i_size)) { + if (cur_offset > actual_len) + i_size = actual_len; + else + i_size = cur_offset; + i_size_write(inode, i_size); + btrfs_ordered_update_i_size(inode, i_size, NULL); + } + + ret = btrfs_update_inode(trans, root, inode); + + if (ret) { + btrfs_abort_transaction(trans, root, ret); + if (own_trans) + btrfs_end_transaction(trans, root); + break; + } + + if (own_trans) + btrfs_end_transaction(trans, root); + } + return ret; +} + +int btrfs_prealloc_file_range(struct inode *inode, int mode, + u64 start, u64 num_bytes, u64 min_size, + loff_t actual_len, u64 *alloc_hint) +{ + return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, + min_size, actual_len, alloc_hint, + NULL); +} + +int btrfs_prealloc_file_range_trans(struct inode *inode, + struct btrfs_trans_handle *trans, int mode, + u64 start, u64 num_bytes, u64 min_size, + loff_t actual_len, u64 *alloc_hint) +{ + return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, + min_size, actual_len, alloc_hint, trans); +} + +static int btrfs_set_page_dirty(struct page *page) +{ + return __set_page_dirty_nobuffers(page); +} + +static int btrfs_permission(struct inode *inode, int mask) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + umode_t mode = inode->i_mode; + + if (mask & MAY_WRITE && + (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) { + if (btrfs_root_readonly(root)) + return -EROFS; + if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) + return -EACCES; + } + return generic_permission(inode, mask); +} + +static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct inode *inode = NULL; + u64 objectid; + u64 index; + int ret = 0; + + /* + * 5 units required for adding orphan entry + */ + trans = btrfs_start_transaction(root, 5); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = btrfs_find_free_ino(root, &objectid); + if (ret) + goto out; + + inode = btrfs_new_inode(trans, root, dir, NULL, 0, + btrfs_ino(dir), objectid, mode, &index); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + inode = NULL; + goto out; + } + + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; + + inode->i_mapping->a_ops = &btrfs_aops; + BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; + + ret = btrfs_init_inode_security(trans, inode, dir, NULL); + if (ret) + goto out_inode; + + ret = btrfs_update_inode(trans, root, inode); + if (ret) + goto out_inode; + ret = btrfs_orphan_add(trans, inode); + if (ret) + goto out_inode; + + /* + * We set number of links to 0 in btrfs_new_inode(), and here we set + * it to 1 because d_tmpfile() will issue a warning if the count is 0, + * through: + * + * d_tmpfile() -> inode_dec_link_count() -> drop_nlink() + */ + set_nlink(inode, 1); + unlock_new_inode(inode); + d_tmpfile(dentry, inode); + mark_inode_dirty(inode); + +out: + btrfs_end_transaction(trans, root); + if (ret) + iput(inode); + btrfs_balance_delayed_items(root); + btrfs_btree_balance_dirty(root); + return ret; + +out_inode: + unlock_new_inode(inode); + goto out; + +} + +/* Inspired by filemap_check_errors() */ +int btrfs_inode_check_errors(struct inode *inode) +{ + int ret = 0; + + if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) && + test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags)) + ret = -ENOSPC; + if (test_bit(AS_EIO, &inode->i_mapping->flags) && + test_and_clear_bit(AS_EIO, &inode->i_mapping->flags)) + ret = -EIO; + + return ret; +} + +static const struct inode_operations btrfs_dir_inode_operations = { + .getattr = btrfs_getattr, + .lookup = btrfs_lookup, + .create = btrfs_create, + .unlink = btrfs_unlink, + .link = btrfs_link, + .mkdir = btrfs_mkdir, + .rmdir = btrfs_rmdir, + .rename2 = btrfs_rename2, + .symlink = btrfs_symlink, + .setattr = btrfs_setattr, + .mknod = btrfs_mknod, + .setxattr = btrfs_setxattr, + .getxattr = btrfs_getxattr, + .listxattr = btrfs_listxattr, + .removexattr = btrfs_removexattr, + .permission = btrfs_permission, + .get_acl = btrfs_get_acl, + .set_acl = btrfs_set_acl, + .update_time = btrfs_update_time, + .tmpfile = btrfs_tmpfile, +}; +static const struct inode_operations btrfs_dir_ro_inode_operations = { + .lookup = btrfs_lookup, + .permission = btrfs_permission, + .get_acl = btrfs_get_acl, + .set_acl = btrfs_set_acl, + .update_time = btrfs_update_time, +}; + +static const struct file_operations btrfs_dir_file_operations = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .iterate = btrfs_real_readdir, + .unlocked_ioctl = btrfs_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = btrfs_ioctl, +#endif + .release = btrfs_release_file, + .fsync = btrfs_sync_file, +}; + +static struct extent_io_ops btrfs_extent_io_ops = { + .fill_delalloc = run_delalloc_range, + .submit_bio_hook = btrfs_submit_bio_hook, + .merge_bio_hook = btrfs_merge_bio_hook, + .readpage_end_io_hook = btrfs_readpage_end_io_hook, + .writepage_end_io_hook = btrfs_writepage_end_io_hook, + .writepage_start_hook = btrfs_writepage_start_hook, + .set_bit_hook = btrfs_set_bit_hook, + .clear_bit_hook = btrfs_clear_bit_hook, + .merge_extent_hook = btrfs_merge_extent_hook, + .split_extent_hook = btrfs_split_extent_hook, +}; + +/* + * btrfs doesn't support the bmap operation because swapfiles + * use bmap to make a mapping of extents in the file. They assume + * these extents won't change over the life of the file and they + * use the bmap result to do IO directly to the drive. + * + * the btrfs bmap call would return logical addresses that aren't + * suitable for IO and they also will change frequently as COW + * operations happen. So, swapfile + btrfs == corruption. + * + * For now we're avoiding this by dropping bmap. + */ +static const struct address_space_operations btrfs_aops = { + .readpage = btrfs_readpage, + .writepage = btrfs_writepage, + .writepages = btrfs_writepages, + .readpages = btrfs_readpages, + .direct_IO = btrfs_direct_IO, + .invalidatepage = btrfs_invalidatepage, + .releasepage = btrfs_releasepage, + .set_page_dirty = btrfs_set_page_dirty, + .error_remove_page = generic_error_remove_page, +}; + +static const struct address_space_operations btrfs_symlink_aops = { + .readpage = btrfs_readpage, + .writepage = btrfs_writepage, + .invalidatepage = btrfs_invalidatepage, + .releasepage = btrfs_releasepage, +}; + +static const struct inode_operations btrfs_file_inode_operations = { + .getattr = btrfs_getattr, + .setattr = btrfs_setattr, + .setxattr = btrfs_setxattr, + .getxattr = btrfs_getxattr, + .listxattr = btrfs_listxattr, + .removexattr = btrfs_removexattr, + .permission = btrfs_permission, + .fiemap = btrfs_fiemap, + .get_acl = btrfs_get_acl, + .set_acl = btrfs_set_acl, + .update_time = btrfs_update_time, +}; +static const struct inode_operations btrfs_special_inode_operations = { + .getattr = btrfs_getattr, + .setattr = btrfs_setattr, + .permission = btrfs_permission, + .setxattr = btrfs_setxattr, + .getxattr = btrfs_getxattr, + .listxattr = btrfs_listxattr, + .removexattr = btrfs_removexattr, + .get_acl = btrfs_get_acl, + .set_acl = btrfs_set_acl, + .update_time = btrfs_update_time, +}; +static const struct inode_operations btrfs_symlink_inode_operations = { + .readlink = generic_readlink, + .follow_link = page_follow_link_light, + .put_link = page_put_link, + .getattr = btrfs_getattr, + .setattr = btrfs_setattr, + .permission = btrfs_permission, + .setxattr = btrfs_setxattr, + .getxattr = btrfs_getxattr, + .listxattr = btrfs_listxattr, + .removexattr = btrfs_removexattr, + .update_time = btrfs_update_time, +}; + +const struct dentry_operations btrfs_dentry_operations = { + .d_delete = btrfs_dentry_delete, + .d_release = btrfs_dentry_release, +}; |