summaryrefslogtreecommitdiff
path: root/fs/hfsplus/extents.c
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/hfsplus/extents.c
Initial import
Diffstat (limited to 'fs/hfsplus/extents.c')
-rw-r--r--fs/hfsplus/extents.c611
1 files changed, 611 insertions, 0 deletions
diff --git a/fs/hfsplus/extents.c b/fs/hfsplus/extents.c
new file mode 100644
index 000000000..feca524ce
--- /dev/null
+++ b/fs/hfsplus/extents.c
@@ -0,0 +1,611 @@
+/*
+ * linux/fs/hfsplus/extents.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Handling of Extents both in catalog and extents overflow trees
+ */
+
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+
+#include "hfsplus_fs.h"
+#include "hfsplus_raw.h"
+
+/* Compare two extents keys, returns 0 on same, pos/neg for difference */
+int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
+ const hfsplus_btree_key *k2)
+{
+ __be32 k1id, k2id;
+ __be32 k1s, k2s;
+
+ k1id = k1->ext.cnid;
+ k2id = k2->ext.cnid;
+ if (k1id != k2id)
+ return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;
+
+ if (k1->ext.fork_type != k2->ext.fork_type)
+ return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;
+
+ k1s = k1->ext.start_block;
+ k2s = k2->ext.start_block;
+ if (k1s == k2s)
+ return 0;
+ return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
+}
+
+static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
+ u32 block, u8 type)
+{
+ key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
+ key->ext.cnid = cpu_to_be32(cnid);
+ key->ext.start_block = cpu_to_be32(block);
+ key->ext.fork_type = type;
+ key->ext.pad = 0;
+}
+
+static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
+{
+ int i;
+ u32 count;
+
+ for (i = 0; i < 8; ext++, i++) {
+ count = be32_to_cpu(ext->block_count);
+ if (off < count)
+ return be32_to_cpu(ext->start_block) + off;
+ off -= count;
+ }
+ /* panic? */
+ return 0;
+}
+
+static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
+{
+ int i;
+ u32 count = 0;
+
+ for (i = 0; i < 8; ext++, i++)
+ count += be32_to_cpu(ext->block_count);
+ return count;
+}
+
+static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
+{
+ int i;
+
+ ext += 7;
+ for (i = 0; i < 7; ext--, i++)
+ if (ext->block_count)
+ break;
+ return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
+}
+
+static int __hfsplus_ext_write_extent(struct inode *inode,
+ struct hfs_find_data *fd)
+{
+ struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
+ int res;
+
+ WARN_ON(!mutex_is_locked(&hip->extents_lock));
+
+ hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
+ HFSPLUS_IS_RSRC(inode) ?
+ HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
+
+ res = hfs_brec_find(fd, hfs_find_rec_by_key);
+ if (hip->extent_state & HFSPLUS_EXT_NEW) {
+ if (res != -ENOENT)
+ return res;
+ hfs_brec_insert(fd, hip->cached_extents,
+ sizeof(hfsplus_extent_rec));
+ hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
+ } else {
+ if (res)
+ return res;
+ hfs_bnode_write(fd->bnode, hip->cached_extents,
+ fd->entryoffset, fd->entrylength);
+ hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
+ }
+
+ /*
+ * We can't just use hfsplus_mark_inode_dirty here, because we
+ * also get called from hfsplus_write_inode, which should not
+ * redirty the inode. Instead the callers have to be careful
+ * to explicily mark the inode dirty, too.
+ */
+ set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
+
+ return 0;
+}
+
+static int hfsplus_ext_write_extent_locked(struct inode *inode)
+{
+ int res = 0;
+
+ if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
+ struct hfs_find_data fd;
+
+ res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
+ if (res)
+ return res;
+ res = __hfsplus_ext_write_extent(inode, &fd);
+ hfs_find_exit(&fd);
+ }
+ return res;
+}
+
+int hfsplus_ext_write_extent(struct inode *inode)
+{
+ int res;
+
+ mutex_lock(&HFSPLUS_I(inode)->extents_lock);
+ res = hfsplus_ext_write_extent_locked(inode);
+ mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
+
+ return res;
+}
+
+static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
+ struct hfsplus_extent *extent,
+ u32 cnid, u32 block, u8 type)
+{
+ int res;
+
+ hfsplus_ext_build_key(fd->search_key, cnid, block, type);
+ fd->key->ext.cnid = 0;
+ res = hfs_brec_find(fd, hfs_find_rec_by_key);
+ if (res && res != -ENOENT)
+ return res;
+ if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
+ fd->key->ext.fork_type != fd->search_key->ext.fork_type)
+ return -ENOENT;
+ if (fd->entrylength != sizeof(hfsplus_extent_rec))
+ return -EIO;
+ hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
+ sizeof(hfsplus_extent_rec));
+ return 0;
+}
+
+static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
+ struct inode *inode, u32 block)
+{
+ struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
+ int res;
+
+ WARN_ON(!mutex_is_locked(&hip->extents_lock));
+
+ if (hip->extent_state & HFSPLUS_EXT_DIRTY) {
+ res = __hfsplus_ext_write_extent(inode, fd);
+ if (res)
+ return res;
+ }
+
+ res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
+ block, HFSPLUS_IS_RSRC(inode) ?
+ HFSPLUS_TYPE_RSRC :
+ HFSPLUS_TYPE_DATA);
+ if (!res) {
+ hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
+ hip->cached_blocks =
+ hfsplus_ext_block_count(hip->cached_extents);
+ } else {
+ hip->cached_start = hip->cached_blocks = 0;
+ hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
+ }
+ return res;
+}
+
+static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
+{
+ struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
+ struct hfs_find_data fd;
+ int res;
+
+ if (block >= hip->cached_start &&
+ block < hip->cached_start + hip->cached_blocks)
+ return 0;
+
+ res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
+ if (!res) {
+ res = __hfsplus_ext_cache_extent(&fd, inode, block);
+ hfs_find_exit(&fd);
+ }
+ return res;
+}
+
+/* Get a block at iblock for inode, possibly allocating if create */
+int hfsplus_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ struct super_block *sb = inode->i_sb;
+ struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
+ struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
+ int res = -EIO;
+ u32 ablock, dblock, mask;
+ sector_t sector;
+ int was_dirty = 0;
+
+ /* Convert inode block to disk allocation block */
+ ablock = iblock >> sbi->fs_shift;
+
+ if (iblock >= hip->fs_blocks) {
+ if (iblock > hip->fs_blocks || !create)
+ return -EIO;
+ if (ablock >= hip->alloc_blocks) {
+ res = hfsplus_file_extend(inode, false);
+ if (res)
+ return res;
+ }
+ } else
+ create = 0;
+
+ if (ablock < hip->first_blocks) {
+ dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
+ goto done;
+ }
+
+ if (inode->i_ino == HFSPLUS_EXT_CNID)
+ return -EIO;
+
+ mutex_lock(&hip->extents_lock);
+
+ /*
+ * hfsplus_ext_read_extent will write out a cached extent into
+ * the extents btree. In that case we may have to mark the inode
+ * dirty even for a pure read of an extent here.
+ */
+ was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
+ res = hfsplus_ext_read_extent(inode, ablock);
+ if (res) {
+ mutex_unlock(&hip->extents_lock);
+ return -EIO;
+ }
+ dblock = hfsplus_ext_find_block(hip->cached_extents,
+ ablock - hip->cached_start);
+ mutex_unlock(&hip->extents_lock);
+
+done:
+ hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n",
+ inode->i_ino, (long long)iblock, dblock);
+
+ mask = (1 << sbi->fs_shift) - 1;
+ sector = ((sector_t)dblock << sbi->fs_shift) +
+ sbi->blockoffset + (iblock & mask);
+ map_bh(bh_result, sb, sector);
+
+ if (create) {
+ set_buffer_new(bh_result);
+ hip->phys_size += sb->s_blocksize;
+ hip->fs_blocks++;
+ inode_add_bytes(inode, sb->s_blocksize);
+ }
+ if (create || was_dirty)
+ mark_inode_dirty(inode);
+ return 0;
+}
+
+static void hfsplus_dump_extent(struct hfsplus_extent *extent)
+{
+ int i;
+
+ hfs_dbg(EXTENT, " ");
+ for (i = 0; i < 8; i++)
+ hfs_dbg_cont(EXTENT, " %u:%u",
+ be32_to_cpu(extent[i].start_block),
+ be32_to_cpu(extent[i].block_count));
+ hfs_dbg_cont(EXTENT, "\n");
+}
+
+static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
+ u32 alloc_block, u32 block_count)
+{
+ u32 count, start;
+ int i;
+
+ hfsplus_dump_extent(extent);
+ for (i = 0; i < 8; extent++, i++) {
+ count = be32_to_cpu(extent->block_count);
+ if (offset == count) {
+ start = be32_to_cpu(extent->start_block);
+ if (alloc_block != start + count) {
+ if (++i >= 8)
+ return -ENOSPC;
+ extent++;
+ extent->start_block = cpu_to_be32(alloc_block);
+ } else
+ block_count += count;
+ extent->block_count = cpu_to_be32(block_count);
+ return 0;
+ } else if (offset < count)
+ break;
+ offset -= count;
+ }
+ /* panic? */
+ return -EIO;
+}
+
+static int hfsplus_free_extents(struct super_block *sb,
+ struct hfsplus_extent *extent,
+ u32 offset, u32 block_nr)
+{
+ u32 count, start;
+ int i;
+ int err = 0;
+
+ hfsplus_dump_extent(extent);
+ for (i = 0; i < 8; extent++, i++) {
+ count = be32_to_cpu(extent->block_count);
+ if (offset == count)
+ goto found;
+ else if (offset < count)
+ break;
+ offset -= count;
+ }
+ /* panic? */
+ return -EIO;
+found:
+ for (;;) {
+ start = be32_to_cpu(extent->start_block);
+ if (count <= block_nr) {
+ err = hfsplus_block_free(sb, start, count);
+ if (err) {
+ pr_err("can't free extent\n");
+ hfs_dbg(EXTENT, " start: %u count: %u\n",
+ start, count);
+ }
+ extent->block_count = 0;
+ extent->start_block = 0;
+ block_nr -= count;
+ } else {
+ count -= block_nr;
+ err = hfsplus_block_free(sb, start + count, block_nr);
+ if (err) {
+ pr_err("can't free extent\n");
+ hfs_dbg(EXTENT, " start: %u count: %u\n",
+ start, count);
+ }
+ extent->block_count = cpu_to_be32(count);
+ block_nr = 0;
+ }
+ if (!block_nr || !i) {
+ /*
+ * Try to free all extents and
+ * return only last error
+ */
+ return err;
+ }
+ i--;
+ extent--;
+ count = be32_to_cpu(extent->block_count);
+ }
+}
+
+int hfsplus_free_fork(struct super_block *sb, u32 cnid,
+ struct hfsplus_fork_raw *fork, int type)
+{
+ struct hfs_find_data fd;
+ hfsplus_extent_rec ext_entry;
+ u32 total_blocks, blocks, start;
+ int res, i;
+
+ total_blocks = be32_to_cpu(fork->total_blocks);
+ if (!total_blocks)
+ return 0;
+
+ blocks = 0;
+ for (i = 0; i < 8; i++)
+ blocks += be32_to_cpu(fork->extents[i].block_count);
+
+ res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
+ if (res)
+ return res;
+ if (total_blocks == blocks)
+ return 0;
+
+ res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
+ if (res)
+ return res;
+ do {
+ res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
+ total_blocks, type);
+ if (res)
+ break;
+ start = be32_to_cpu(fd.key->ext.start_block);
+ hfsplus_free_extents(sb, ext_entry,
+ total_blocks - start,
+ total_blocks);
+ hfs_brec_remove(&fd);
+ total_blocks = start;
+ } while (total_blocks > blocks);
+ hfs_find_exit(&fd);
+
+ return res;
+}
+
+int hfsplus_file_extend(struct inode *inode, bool zeroout)
+{
+ struct super_block *sb = inode->i_sb;
+ struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
+ struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
+ u32 start, len, goal;
+ int res;
+
+ if (sbi->alloc_file->i_size * 8 <
+ sbi->total_blocks - sbi->free_blocks + 8) {
+ /* extend alloc file */
+ pr_err("extend alloc file! (%llu,%u,%u)\n",
+ sbi->alloc_file->i_size * 8,
+ sbi->total_blocks, sbi->free_blocks);
+ return -ENOSPC;
+ }
+
+ mutex_lock(&hip->extents_lock);
+ if (hip->alloc_blocks == hip->first_blocks)
+ goal = hfsplus_ext_lastblock(hip->first_extents);
+ else {
+ res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
+ if (res)
+ goto out;
+ goal = hfsplus_ext_lastblock(hip->cached_extents);
+ }
+
+ len = hip->clump_blocks;
+ start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
+ if (start >= sbi->total_blocks) {
+ start = hfsplus_block_allocate(sb, goal, 0, &len);
+ if (start >= goal) {
+ res = -ENOSPC;
+ goto out;
+ }
+ }
+
+ if (zeroout) {
+ res = sb_issue_zeroout(sb, start, len, GFP_NOFS);
+ if (res)
+ goto out;
+ }
+
+ hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
+
+ if (hip->alloc_blocks <= hip->first_blocks) {
+ if (!hip->first_blocks) {
+ hfs_dbg(EXTENT, "first extents\n");
+ /* no extents yet */
+ hip->first_extents[0].start_block = cpu_to_be32(start);
+ hip->first_extents[0].block_count = cpu_to_be32(len);
+ res = 0;
+ } else {
+ /* try to append to extents in inode */
+ res = hfsplus_add_extent(hip->first_extents,
+ hip->alloc_blocks,
+ start, len);
+ if (res == -ENOSPC)
+ goto insert_extent;
+ }
+ if (!res) {
+ hfsplus_dump_extent(hip->first_extents);
+ hip->first_blocks += len;
+ }
+ } else {
+ res = hfsplus_add_extent(hip->cached_extents,
+ hip->alloc_blocks - hip->cached_start,
+ start, len);
+ if (!res) {
+ hfsplus_dump_extent(hip->cached_extents);
+ hip->extent_state |= HFSPLUS_EXT_DIRTY;
+ hip->cached_blocks += len;
+ } else if (res == -ENOSPC)
+ goto insert_extent;
+ }
+out:
+ if (!res) {
+ hip->alloc_blocks += len;
+ mutex_unlock(&hip->extents_lock);
+ hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
+ return 0;
+ }
+ mutex_unlock(&hip->extents_lock);
+ return res;
+
+insert_extent:
+ hfs_dbg(EXTENT, "insert new extent\n");
+ res = hfsplus_ext_write_extent_locked(inode);
+ if (res)
+ goto out;
+
+ memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
+ hip->cached_extents[0].start_block = cpu_to_be32(start);
+ hip->cached_extents[0].block_count = cpu_to_be32(len);
+ hfsplus_dump_extent(hip->cached_extents);
+ hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
+ hip->cached_start = hip->alloc_blocks;
+ hip->cached_blocks = len;
+
+ res = 0;
+ goto out;
+}
+
+void hfsplus_file_truncate(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
+ struct hfs_find_data fd;
+ u32 alloc_cnt, blk_cnt, start;
+ int res;
+
+ hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n",
+ inode->i_ino, (long long)hip->phys_size, inode->i_size);
+
+ if (inode->i_size > hip->phys_size) {
+ struct address_space *mapping = inode->i_mapping;
+ struct page *page;
+ void *fsdata;
+ loff_t size = inode->i_size;
+
+ res = pagecache_write_begin(NULL, mapping, size, 0,
+ AOP_FLAG_UNINTERRUPTIBLE,
+ &page, &fsdata);
+ if (res)
+ return;
+ res = pagecache_write_end(NULL, mapping, size,
+ 0, 0, page, fsdata);
+ if (res < 0)
+ return;
+ mark_inode_dirty(inode);
+ return;
+ } else if (inode->i_size == hip->phys_size)
+ return;
+
+ blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
+ HFSPLUS_SB(sb)->alloc_blksz_shift;
+
+ mutex_lock(&hip->extents_lock);
+
+ alloc_cnt = hip->alloc_blocks;
+ if (blk_cnt == alloc_cnt)
+ goto out_unlock;
+
+ res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
+ if (res) {
+ mutex_unlock(&hip->extents_lock);
+ /* XXX: We lack error handling of hfsplus_file_truncate() */
+ return;
+ }
+ while (1) {
+ if (alloc_cnt == hip->first_blocks) {
+ hfsplus_free_extents(sb, hip->first_extents,
+ alloc_cnt, alloc_cnt - blk_cnt);
+ hfsplus_dump_extent(hip->first_extents);
+ hip->first_blocks = blk_cnt;
+ break;
+ }
+ res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
+ if (res)
+ break;
+ start = hip->cached_start;
+ hfsplus_free_extents(sb, hip->cached_extents,
+ alloc_cnt - start, alloc_cnt - blk_cnt);
+ hfsplus_dump_extent(hip->cached_extents);
+ if (blk_cnt > start) {
+ hip->extent_state |= HFSPLUS_EXT_DIRTY;
+ break;
+ }
+ alloc_cnt = start;
+ hip->cached_start = hip->cached_blocks = 0;
+ hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
+ hfs_brec_remove(&fd);
+ }
+ hfs_find_exit(&fd);
+
+ hip->alloc_blocks = blk_cnt;
+out_unlock:
+ mutex_unlock(&hip->extents_lock);
+ hip->phys_size = inode->i_size;
+ hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
+ sb->s_blocksize_bits;
+ inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
+ hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
+}