diff options
| author | Chris Mason <chris.mason@oracle.com> | 2007-04-10 13:20:21 -0400 |
|---|---|---|
| committer | David Woodhouse <dwmw2@hera.kernel.org> | 2007-04-10 13:20:21 -0400 |
| commit | 48ddc6f44b5a167c00573b6012727d674e9c667a (patch) | |
| tree | b382eeb58ed0f7644e1b84b9fa752d8c24b64176 /fs | |
| parent | d0dbc6245cefa36e19dff49c557ccf05e3063e9c (diff) | |
Btrfs: cow file extents before writing
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/super.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 3e8bfb0e5d7..91aa1b4c50a 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1020,7 +1020,7 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock, ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino, - iblock << inode->i_blkbits, 0); + iblock << inode->i_blkbits, 1); if (ret < 0) { err = ret; goto out; @@ -1040,9 +1040,25 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock, blocknr = btrfs_file_extent_disk_blocknr(item); blocknr += btrfs_file_extent_offset(item); - /* exact match found, use it */ + /* exact match found, use it, FIXME, deal with extents + * other than the page size + */ if (ret == 0) { err = 0; + BUG_ON(btrfs_file_extent_disk_num_blocks(item) != 1); + if (btrfs_file_extent_generation(item) != trans->transid) { + struct btrfs_key ins; + ret = btrfs_alloc_extent(trans, root, 1, + blocknr, (u64)-1, &ins); + BUG_ON(ret); + btrfs_set_file_extent_disk_blocknr(item, ins.objectid); + mark_buffer_dirty(path->nodes[0]); + ret = btrfs_free_extent(trans, root, + blocknr, 1, 0); + BUG_ON(ret); + blocknr = ins.objectid; + + } map_bh(result, inode->i_sb, blocknr); goto out; } |