diff options
Diffstat (limited to 'fs/btrfs/ordered-data.c')
| -rw-r--r-- | fs/btrfs/ordered-data.c | 1051 |
1 files changed, 1051 insertions, 0 deletions
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c new file mode 100644 index 000000000..760c4a5e0 --- /dev/null +++ b/fs/btrfs/ordered-data.c @@ -0,0 +1,1051 @@ +/* + * 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/slab.h> +#include <linux/blkdev.h> +#include <linux/writeback.h> +#include <linux/pagevec.h> +#include "ctree.h" +#include "transaction.h" +#include "btrfs_inode.h" +#include "extent_io.h" +#include "disk-io.h" + +static struct kmem_cache *btrfs_ordered_extent_cache; + +static u64 entry_end(struct btrfs_ordered_extent *entry) +{ + if (entry->file_offset + entry->len < entry->file_offset) + return (u64)-1; + return entry->file_offset + entry->len; +} + +/* returns NULL if the insertion worked, or it returns the node it did find + * in the tree + */ +static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset, + struct rb_node *node) +{ + struct rb_node **p = &root->rb_node; + struct rb_node *parent = NULL; + struct btrfs_ordered_extent *entry; + + while (*p) { + parent = *p; + entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node); + + if (file_offset < entry->file_offset) + p = &(*p)->rb_left; + else if (file_offset >= entry_end(entry)) + p = &(*p)->rb_right; + else + return parent; + } + + rb_link_node(node, parent, p); + rb_insert_color(node, root); + return NULL; +} + +static void ordered_data_tree_panic(struct inode *inode, int errno, + u64 offset) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + btrfs_panic(fs_info, errno, "Inconsistency in ordered tree at offset " + "%llu", offset); +} + +/* + * look for a given offset in the tree, and if it can't be found return the + * first lesser offset + */ +static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset, + struct rb_node **prev_ret) +{ + struct rb_node *n = root->rb_node; + struct rb_node *prev = NULL; + struct rb_node *test; + struct btrfs_ordered_extent *entry; + struct btrfs_ordered_extent *prev_entry = NULL; + + while (n) { + entry = rb_entry(n, struct btrfs_ordered_extent, rb_node); + prev = n; + prev_entry = entry; + + if (file_offset < entry->file_offset) + n = n->rb_left; + else if (file_offset >= entry_end(entry)) + n = n->rb_right; + else + return n; + } + if (!prev_ret) + return NULL; + + while (prev && file_offset >= entry_end(prev_entry)) { + test = rb_next(prev); + if (!test) + break; + prev_entry = rb_entry(test, struct btrfs_ordered_extent, + rb_node); + if (file_offset < entry_end(prev_entry)) + break; + + prev = test; + } + if (prev) + prev_entry = rb_entry(prev, struct btrfs_ordered_extent, + rb_node); + while (prev && file_offset < entry_end(prev_entry)) { + test = rb_prev(prev); + if (!test) + break; + prev_entry = rb_entry(test, struct btrfs_ordered_extent, + rb_node); + prev = test; + } + *prev_ret = prev; + return NULL; +} + +/* + * helper to check if a given offset is inside a given entry + */ +static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset) +{ + if (file_offset < entry->file_offset || + entry->file_offset + entry->len <= file_offset) + return 0; + return 1; +} + +static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset, + u64 len) +{ + if (file_offset + len <= entry->file_offset || + entry->file_offset + entry->len <= file_offset) + return 0; + return 1; +} + +/* + * look find the first ordered struct that has this offset, otherwise + * the first one less than this offset + */ +static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree, + u64 file_offset) +{ + struct rb_root *root = &tree->tree; + struct rb_node *prev = NULL; + struct rb_node *ret; + struct btrfs_ordered_extent *entry; + + if (tree->last) { + entry = rb_entry(tree->last, struct btrfs_ordered_extent, + rb_node); + if (offset_in_entry(entry, file_offset)) + return tree->last; + } + ret = __tree_search(root, file_offset, &prev); + if (!ret) + ret = prev; + if (ret) + tree->last = ret; + return ret; +} + +/* allocate and add a new ordered_extent into the per-inode tree. + * file_offset is the logical offset in the file + * + * start is the disk block number of an extent already reserved in the + * extent allocation tree + * + * len is the length of the extent + * + * The tree is given a single reference on the ordered extent that was + * inserted. + */ +static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset, + u64 start, u64 len, u64 disk_len, + int type, int dio, int compress_type) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_ordered_inode_tree *tree; + struct rb_node *node; + struct btrfs_ordered_extent *entry; + + tree = &BTRFS_I(inode)->ordered_tree; + entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS); + if (!entry) + return -ENOMEM; + + entry->file_offset = file_offset; + entry->start = start; + entry->len = len; + if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) && + !(type == BTRFS_ORDERED_NOCOW)) + entry->csum_bytes_left = disk_len; + entry->disk_len = disk_len; + entry->bytes_left = len; + entry->inode = igrab(inode); + entry->compress_type = compress_type; + entry->truncated_len = (u64)-1; + if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE) + set_bit(type, &entry->flags); + + if (dio) + set_bit(BTRFS_ORDERED_DIRECT, &entry->flags); + + /* one ref for the tree */ + atomic_set(&entry->refs, 1); + init_waitqueue_head(&entry->wait); + INIT_LIST_HEAD(&entry->list); + INIT_LIST_HEAD(&entry->root_extent_list); + INIT_LIST_HEAD(&entry->work_list); + init_completion(&entry->completion); + INIT_LIST_HEAD(&entry->log_list); + INIT_LIST_HEAD(&entry->trans_list); + + trace_btrfs_ordered_extent_add(inode, entry); + + spin_lock_irq(&tree->lock); + node = tree_insert(&tree->tree, file_offset, + &entry->rb_node); + if (node) + ordered_data_tree_panic(inode, -EEXIST, file_offset); + spin_unlock_irq(&tree->lock); + + spin_lock(&root->ordered_extent_lock); + list_add_tail(&entry->root_extent_list, + &root->ordered_extents); + root->nr_ordered_extents++; + if (root->nr_ordered_extents == 1) { + spin_lock(&root->fs_info->ordered_root_lock); + BUG_ON(!list_empty(&root->ordered_root)); + list_add_tail(&root->ordered_root, + &root->fs_info->ordered_roots); + spin_unlock(&root->fs_info->ordered_root_lock); + } + spin_unlock(&root->ordered_extent_lock); + + return 0; +} + +int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset, + u64 start, u64 len, u64 disk_len, int type) +{ + return __btrfs_add_ordered_extent(inode, file_offset, start, len, + disk_len, type, 0, + BTRFS_COMPRESS_NONE); +} + +int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset, + u64 start, u64 len, u64 disk_len, int type) +{ + return __btrfs_add_ordered_extent(inode, file_offset, start, len, + disk_len, type, 1, + BTRFS_COMPRESS_NONE); +} + +int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset, + u64 start, u64 len, u64 disk_len, + int type, int compress_type) +{ + return __btrfs_add_ordered_extent(inode, file_offset, start, len, + disk_len, type, 0, + compress_type); +} + +/* + * Add a struct btrfs_ordered_sum into the list of checksums to be inserted + * when an ordered extent is finished. If the list covers more than one + * ordered extent, it is split across multiples. + */ +void btrfs_add_ordered_sum(struct inode *inode, + struct btrfs_ordered_extent *entry, + struct btrfs_ordered_sum *sum) +{ + struct btrfs_ordered_inode_tree *tree; + + tree = &BTRFS_I(inode)->ordered_tree; + spin_lock_irq(&tree->lock); + list_add_tail(&sum->list, &entry->list); + WARN_ON(entry->csum_bytes_left < sum->len); + entry->csum_bytes_left -= sum->len; + if (entry->csum_bytes_left == 0) + wake_up(&entry->wait); + spin_unlock_irq(&tree->lock); +} + +/* + * this is used to account for finished IO across a given range + * of the file. The IO may span ordered extents. If + * a given ordered_extent is completely done, 1 is returned, otherwise + * 0. + * + * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used + * to make sure this function only returns 1 once for a given ordered extent. + * + * file_offset is updated to one byte past the range that is recorded as + * complete. This allows you to walk forward in the file. + */ +int btrfs_dec_test_first_ordered_pending(struct inode *inode, + struct btrfs_ordered_extent **cached, + u64 *file_offset, u64 io_size, int uptodate) +{ + struct btrfs_ordered_inode_tree *tree; + struct rb_node *node; + struct btrfs_ordered_extent *entry = NULL; + int ret; + unsigned long flags; + u64 dec_end; + u64 dec_start; + u64 to_dec; + + tree = &BTRFS_I(inode)->ordered_tree; + spin_lock_irqsave(&tree->lock, flags); + node = tree_search(tree, *file_offset); + if (!node) { + ret = 1; + goto out; + } + + entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); + if (!offset_in_entry(entry, *file_offset)) { + ret = 1; + goto out; + } + + dec_start = max(*file_offset, entry->file_offset); + dec_end = min(*file_offset + io_size, entry->file_offset + + entry->len); + *file_offset = dec_end; + if (dec_start > dec_end) { + btrfs_crit(BTRFS_I(inode)->root->fs_info, + "bad ordering dec_start %llu end %llu", dec_start, dec_end); + } + to_dec = dec_end - dec_start; + if (to_dec > entry->bytes_left) { + btrfs_crit(BTRFS_I(inode)->root->fs_info, + "bad ordered accounting left %llu size %llu", + entry->bytes_left, to_dec); + } + entry->bytes_left -= to_dec; + if (!uptodate) + set_bit(BTRFS_ORDERED_IOERR, &entry->flags); + + if (entry->bytes_left == 0) { + ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags); + if (waitqueue_active(&entry->wait)) + wake_up(&entry->wait); + } else { + ret = 1; + } +out: + if (!ret && cached && entry) { + *cached = entry; + atomic_inc(&entry->refs); + } + spin_unlock_irqrestore(&tree->lock, flags); + return ret == 0; +} + +/* + * this is used to account for finished IO across a given range + * of the file. The IO should not span ordered extents. If + * a given ordered_extent is completely done, 1 is returned, otherwise + * 0. + * + * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used + * to make sure this function only returns 1 once for a given ordered extent. + */ +int btrfs_dec_test_ordered_pending(struct inode *inode, + struct btrfs_ordered_extent **cached, + u64 file_offset, u64 io_size, int uptodate) +{ + struct btrfs_ordered_inode_tree *tree; + struct rb_node *node; + struct btrfs_ordered_extent *entry = NULL; + unsigned long flags; + int ret; + + tree = &BTRFS_I(inode)->ordered_tree; + spin_lock_irqsave(&tree->lock, flags); + if (cached && *cached) { + entry = *cached; + goto have_entry; + } + + node = tree_search(tree, file_offset); + if (!node) { + ret = 1; + goto out; + } + + entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); +have_entry: + if (!offset_in_entry(entry, file_offset)) { + ret = 1; + goto out; + } + + if (io_size > entry->bytes_left) { + btrfs_crit(BTRFS_I(inode)->root->fs_info, + "bad ordered accounting left %llu size %llu", + entry->bytes_left, io_size); + } + entry->bytes_left -= io_size; + if (!uptodate) + set_bit(BTRFS_ORDERED_IOERR, &entry->flags); + + if (entry->bytes_left == 0) { + ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags); + if (waitqueue_active(&entry->wait)) + wake_up(&entry->wait); + } else { + ret = 1; + } +out: + if (!ret && cached && entry) { + *cached = entry; + atomic_inc(&entry->refs); + } + spin_unlock_irqrestore(&tree->lock, flags); + return ret == 0; +} + +/* Needs to either be called under a log transaction or the log_mutex */ +void btrfs_get_logged_extents(struct inode *inode, + struct list_head *logged_list, + const loff_t start, + const loff_t end) +{ + struct btrfs_ordered_inode_tree *tree; + struct btrfs_ordered_extent *ordered; + struct rb_node *n; + struct rb_node *prev; + + tree = &BTRFS_I(inode)->ordered_tree; + spin_lock_irq(&tree->lock); + n = __tree_search(&tree->tree, end, &prev); + if (!n) + n = prev; + for (; n; n = rb_prev(n)) { + ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node); + if (ordered->file_offset > end) + continue; + if (entry_end(ordered) <= start) + break; + if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags)) + continue; + list_add(&ordered->log_list, logged_list); + atomic_inc(&ordered->refs); + } + spin_unlock_irq(&tree->lock); +} + +void btrfs_put_logged_extents(struct list_head *logged_list) +{ + struct btrfs_ordered_extent *ordered; + + while (!list_empty(logged_list)) { + ordered = list_first_entry(logged_list, + struct btrfs_ordered_extent, + log_list); + list_del_init(&ordered->log_list); + btrfs_put_ordered_extent(ordered); + } +} + +void btrfs_submit_logged_extents(struct list_head *logged_list, + struct btrfs_root *log) +{ + int index = log->log_transid % 2; + + spin_lock_irq(&log->log_extents_lock[index]); + list_splice_tail(logged_list, &log->logged_list[index]); + spin_unlock_irq(&log->log_extents_lock[index]); +} + +void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans, + struct btrfs_root *log, u64 transid) +{ + struct btrfs_ordered_extent *ordered; + int index = transid % 2; + + spin_lock_irq(&log->log_extents_lock[index]); + while (!list_empty(&log->logged_list[index])) { + ordered = list_first_entry(&log->logged_list[index], + struct btrfs_ordered_extent, + log_list); + list_del_init(&ordered->log_list); + spin_unlock_irq(&log->log_extents_lock[index]); + + if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) && + !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) { + struct inode *inode = ordered->inode; + u64 start = ordered->file_offset; + u64 end = ordered->file_offset + ordered->len - 1; + + WARN_ON(!inode); + filemap_fdatawrite_range(inode->i_mapping, start, end); + } + wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE, + &ordered->flags)); + + list_add_tail(&ordered->trans_list, &trans->ordered); + spin_lock_irq(&log->log_extents_lock[index]); + } + spin_unlock_irq(&log->log_extents_lock[index]); +} + +void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid) +{ + struct btrfs_ordered_extent *ordered; + int index = transid % 2; + + spin_lock_irq(&log->log_extents_lock[index]); + while (!list_empty(&log->logged_list[index])) { + ordered = list_first_entry(&log->logged_list[index], + struct btrfs_ordered_extent, + log_list); + list_del_init(&ordered->log_list); + spin_unlock_irq(&log->log_extents_lock[index]); + btrfs_put_ordered_extent(ordered); + spin_lock_irq(&log->log_extents_lock[index]); + } + spin_unlock_irq(&log->log_extents_lock[index]); +} + +/* + * used to drop a reference on an ordered extent. This will free + * the extent if the last reference is dropped + */ +void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry) +{ + struct list_head *cur; + struct btrfs_ordered_sum *sum; + + trace_btrfs_ordered_extent_put(entry->inode, entry); + + if (atomic_dec_and_test(&entry->refs)) { + if (entry->inode) + btrfs_add_delayed_iput(entry->inode); + while (!list_empty(&entry->list)) { + cur = entry->list.next; + sum = list_entry(cur, struct btrfs_ordered_sum, list); + list_del(&sum->list); + kfree(sum); + } + kmem_cache_free(btrfs_ordered_extent_cache, entry); + } +} + +/* + * remove an ordered extent from the tree. No references are dropped + * and waiters are woken up. + */ +void btrfs_remove_ordered_extent(struct inode *inode, + struct btrfs_ordered_extent *entry) +{ + struct btrfs_ordered_inode_tree *tree; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct rb_node *node; + + tree = &BTRFS_I(inode)->ordered_tree; + spin_lock_irq(&tree->lock); + node = &entry->rb_node; + rb_erase(node, &tree->tree); + if (tree->last == node) + tree->last = NULL; + set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags); + spin_unlock_irq(&tree->lock); + + spin_lock(&root->ordered_extent_lock); + list_del_init(&entry->root_extent_list); + root->nr_ordered_extents--; + + trace_btrfs_ordered_extent_remove(inode, entry); + + if (!root->nr_ordered_extents) { + spin_lock(&root->fs_info->ordered_root_lock); + BUG_ON(list_empty(&root->ordered_root)); + list_del_init(&root->ordered_root); + spin_unlock(&root->fs_info->ordered_root_lock); + } + spin_unlock(&root->ordered_extent_lock); + wake_up(&entry->wait); +} + +static void btrfs_run_ordered_extent_work(struct btrfs_work *work) +{ + struct btrfs_ordered_extent *ordered; + + ordered = container_of(work, struct btrfs_ordered_extent, flush_work); + btrfs_start_ordered_extent(ordered->inode, ordered, 1); + complete(&ordered->completion); +} + +/* + * wait for all the ordered extents in a root. This is done when balancing + * space between drives. + */ +int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr) +{ + struct list_head splice, works; + struct btrfs_ordered_extent *ordered, *next; + int count = 0; + + INIT_LIST_HEAD(&splice); + INIT_LIST_HEAD(&works); + + mutex_lock(&root->ordered_extent_mutex); + spin_lock(&root->ordered_extent_lock); + list_splice_init(&root->ordered_extents, &splice); + while (!list_empty(&splice) && nr) { + ordered = list_first_entry(&splice, struct btrfs_ordered_extent, + root_extent_list); + list_move_tail(&ordered->root_extent_list, + &root->ordered_extents); + atomic_inc(&ordered->refs); + spin_unlock(&root->ordered_extent_lock); + + btrfs_init_work(&ordered->flush_work, + btrfs_flush_delalloc_helper, + btrfs_run_ordered_extent_work, NULL, NULL); + list_add_tail(&ordered->work_list, &works); + btrfs_queue_work(root->fs_info->flush_workers, + &ordered->flush_work); + + cond_resched(); + spin_lock(&root->ordered_extent_lock); + if (nr != -1) + nr--; + count++; + } + list_splice_tail(&splice, &root->ordered_extents); + spin_unlock(&root->ordered_extent_lock); + + list_for_each_entry_safe(ordered, next, &works, work_list) { + list_del_init(&ordered->work_list); + wait_for_completion(&ordered->completion); + btrfs_put_ordered_extent(ordered); + cond_resched(); + } + mutex_unlock(&root->ordered_extent_mutex); + + return count; +} + +void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr) +{ + struct btrfs_root *root; + struct list_head splice; + int done; + + INIT_LIST_HEAD(&splice); + + mutex_lock(&fs_info->ordered_operations_mutex); + spin_lock(&fs_info->ordered_root_lock); + list_splice_init(&fs_info->ordered_roots, &splice); + while (!list_empty(&splice) && nr) { + root = list_first_entry(&splice, struct btrfs_root, + ordered_root); + root = btrfs_grab_fs_root(root); + BUG_ON(!root); + list_move_tail(&root->ordered_root, + &fs_info->ordered_roots); + spin_unlock(&fs_info->ordered_root_lock); + + done = btrfs_wait_ordered_extents(root, nr); + btrfs_put_fs_root(root); + + spin_lock(&fs_info->ordered_root_lock); + if (nr != -1) { + nr -= done; + WARN_ON(nr < 0); + } + } + list_splice_tail(&splice, &fs_info->ordered_roots); + spin_unlock(&fs_info->ordered_root_lock); + mutex_unlock(&fs_info->ordered_operations_mutex); +} + +/* + * Used to start IO or wait for a given ordered extent to finish. + * + * If wait is one, this effectively waits on page writeback for all the pages + * in the extent, and it waits on the io completion code to insert + * metadata into the btree corresponding to the extent + */ +void btrfs_start_ordered_extent(struct inode *inode, + struct btrfs_ordered_extent *entry, + int wait) +{ + u64 start = entry->file_offset; + u64 end = start + entry->len - 1; + + trace_btrfs_ordered_extent_start(inode, entry); + + /* + * pages in the range can be dirty, clean or writeback. We + * start IO on any dirty ones so the wait doesn't stall waiting + * for the flusher thread to find them + */ + if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags)) + filemap_fdatawrite_range(inode->i_mapping, start, end); + if (wait) { + wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE, + &entry->flags)); + } +} + +/* + * Used to wait on ordered extents across a large range of bytes. + */ +int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len) +{ + int ret = 0; + int ret_wb = 0; + u64 end; + u64 orig_end; + struct btrfs_ordered_extent *ordered; + + if (start + len < start) { + orig_end = INT_LIMIT(loff_t); + } else { + orig_end = start + len - 1; + if (orig_end > INT_LIMIT(loff_t)) + orig_end = INT_LIMIT(loff_t); + } + + /* start IO across the range first to instantiate any delalloc + * extents + */ + ret = btrfs_fdatawrite_range(inode, start, orig_end); + if (ret) + return ret; + + /* + * If we have a writeback error don't return immediately. Wait first + * for any ordered extents that haven't completed yet. This is to make + * sure no one can dirty the same page ranges and call writepages() + * before the ordered extents complete - to avoid failures (-EEXIST) + * when adding the new ordered extents to the ordered tree. + */ + ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end); + + end = orig_end; + while (1) { + ordered = btrfs_lookup_first_ordered_extent(inode, end); + if (!ordered) + break; + if (ordered->file_offset > orig_end) { + btrfs_put_ordered_extent(ordered); + break; + } + if (ordered->file_offset + ordered->len <= start) { + btrfs_put_ordered_extent(ordered); + break; + } + btrfs_start_ordered_extent(inode, ordered, 1); + end = ordered->file_offset; + if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags)) + ret = -EIO; + btrfs_put_ordered_extent(ordered); + if (ret || end == 0 || end == start) + break; + end--; + } + return ret_wb ? ret_wb : ret; +} + +/* + * find an ordered extent corresponding to file_offset. return NULL if + * nothing is found, otherwise take a reference on the extent and return it + */ +struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode, + u64 file_offset) +{ + struct btrfs_ordered_inode_tree *tree; + struct rb_node *node; + struct btrfs_ordered_extent *entry = NULL; + + tree = &BTRFS_I(inode)->ordered_tree; + spin_lock_irq(&tree->lock); + node = tree_search(tree, file_offset); + if (!node) + goto out; + + entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); + if (!offset_in_entry(entry, file_offset)) + entry = NULL; + if (entry) + atomic_inc(&entry->refs); +out: + spin_unlock_irq(&tree->lock); + return entry; +} + +/* Since the DIO code tries to lock a wide area we need to look for any ordered + * extents that exist in the range, rather than just the start of the range. + */ +struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode, + u64 file_offset, + u64 len) +{ + struct btrfs_ordered_inode_tree *tree; + struct rb_node *node; + struct btrfs_ordered_extent *entry = NULL; + + tree = &BTRFS_I(inode)->ordered_tree; + spin_lock_irq(&tree->lock); + node = tree_search(tree, file_offset); + if (!node) { + node = tree_search(tree, file_offset + len); + if (!node) + goto out; + } + + while (1) { + entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); + if (range_overlaps(entry, file_offset, len)) + break; + + if (entry->file_offset >= file_offset + len) { + entry = NULL; + break; + } + entry = NULL; + node = rb_next(node); + if (!node) + break; + } +out: + if (entry) + atomic_inc(&entry->refs); + spin_unlock_irq(&tree->lock); + return entry; +} + +/* + * lookup and return any extent before 'file_offset'. NULL is returned + * if none is found + */ +struct btrfs_ordered_extent * +btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset) +{ + struct btrfs_ordered_inode_tree *tree; + struct rb_node *node; + struct btrfs_ordered_extent *entry = NULL; + + tree = &BTRFS_I(inode)->ordered_tree; + spin_lock_irq(&tree->lock); + node = tree_search(tree, file_offset); + if (!node) + goto out; + + entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); + atomic_inc(&entry->refs); +out: + spin_unlock_irq(&tree->lock); + return entry; +} + +/* + * After an extent is done, call this to conditionally update the on disk + * i_size. i_size is updated to cover any fully written part of the file. + */ +int btrfs_ordered_update_i_size(struct inode *inode, u64 offset, + struct btrfs_ordered_extent *ordered) +{ + struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree; + u64 disk_i_size; + u64 new_i_size; + u64 i_size = i_size_read(inode); + struct rb_node *node; + struct rb_node *prev = NULL; + struct btrfs_ordered_extent *test; + int ret = 1; + + spin_lock_irq(&tree->lock); + if (ordered) { + offset = entry_end(ordered); + if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags)) + offset = min(offset, + ordered->file_offset + + ordered->truncated_len); + } else { + offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize); + } + disk_i_size = BTRFS_I(inode)->disk_i_size; + + /* truncate file */ + if (disk_i_size > i_size) { + BTRFS_I(inode)->disk_i_size = i_size; + ret = 0; + goto out; + } + + /* + * if the disk i_size is already at the inode->i_size, or + * this ordered extent is inside the disk i_size, we're done + */ + if (disk_i_size == i_size) + goto out; + + /* + * We still need to update disk_i_size if outstanding_isize is greater + * than disk_i_size. + */ + if (offset <= disk_i_size && + (!ordered || ordered->outstanding_isize <= disk_i_size)) + goto out; + + /* + * walk backward from this ordered extent to disk_i_size. + * if we find an ordered extent then we can't update disk i_size + * yet + */ + if (ordered) { + node = rb_prev(&ordered->rb_node); + } else { + prev = tree_search(tree, offset); + /* + * we insert file extents without involving ordered struct, + * so there should be no ordered struct cover this offset + */ + if (prev) { + test = rb_entry(prev, struct btrfs_ordered_extent, + rb_node); + BUG_ON(offset_in_entry(test, offset)); + } + node = prev; + } + for (; node; node = rb_prev(node)) { + test = rb_entry(node, struct btrfs_ordered_extent, rb_node); + + /* We treat this entry as if it doesnt exist */ + if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags)) + continue; + if (test->file_offset + test->len <= disk_i_size) + break; + if (test->file_offset >= i_size) + break; + if (entry_end(test) > disk_i_size) { + /* + * we don't update disk_i_size now, so record this + * undealt i_size. Or we will not know the real + * i_size. + */ + if (test->outstanding_isize < offset) + test->outstanding_isize = offset; + if (ordered && + ordered->outstanding_isize > + test->outstanding_isize) + test->outstanding_isize = + ordered->outstanding_isize; + goto out; + } + } + new_i_size = min_t(u64, offset, i_size); + + /* + * Some ordered extents may completed before the current one, and + * we hold the real i_size in ->outstanding_isize. + */ + if (ordered && ordered->outstanding_isize > new_i_size) + new_i_size = min_t(u64, ordered->outstanding_isize, i_size); + BTRFS_I(inode)->disk_i_size = new_i_size; + ret = 0; +out: + /* + * We need to do this because we can't remove ordered extents until + * after the i_disk_size has been updated and then the inode has been + * updated to reflect the change, so we need to tell anybody who finds + * this ordered extent that we've already done all the real work, we + * just haven't completed all the other work. + */ + if (ordered) + set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags); + spin_unlock_irq(&tree->lock); + return ret; +} + +/* + * search the ordered extents for one corresponding to 'offset' and + * try to find a checksum. This is used because we allow pages to + * be reclaimed before their checksum is actually put into the btree + */ +int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, + u32 *sum, int len) +{ + struct btrfs_ordered_sum *ordered_sum; + struct btrfs_ordered_extent *ordered; + struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree; + unsigned long num_sectors; + unsigned long i; + u32 sectorsize = BTRFS_I(inode)->root->sectorsize; + int index = 0; + + ordered = btrfs_lookup_ordered_extent(inode, offset); + if (!ordered) + return 0; + + spin_lock_irq(&tree->lock); + list_for_each_entry_reverse(ordered_sum, &ordered->list, list) { + if (disk_bytenr >= ordered_sum->bytenr && + disk_bytenr < ordered_sum->bytenr + ordered_sum->len) { + i = (disk_bytenr - ordered_sum->bytenr) >> + inode->i_sb->s_blocksize_bits; + num_sectors = ordered_sum->len >> + inode->i_sb->s_blocksize_bits; + num_sectors = min_t(int, len - index, num_sectors - i); + memcpy(sum + index, ordered_sum->sums + i, + num_sectors); + + index += (int)num_sectors; + if (index == len) + goto out; + disk_bytenr += num_sectors * sectorsize; + } + } +out: + spin_unlock_irq(&tree->lock); + btrfs_put_ordered_extent(ordered); + return index; +} + +int __init ordered_data_init(void) +{ + btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent", + sizeof(struct btrfs_ordered_extent), 0, + SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, + NULL); + if (!btrfs_ordered_extent_cache) + return -ENOMEM; + + return 0; +} + +void ordered_data_exit(void) +{ + if (btrfs_ordered_extent_cache) + kmem_cache_destroy(btrfs_ordered_extent_cache); +} |