From: Josef Bacik Date: Wed, 17 Aug 2011 14:19:52 +0000 (-0400) Subject: Btrfs: only reserve space in fallocate if we have to do a preallocate X-Git-Tag: firefly_0821_release~3680^2~3894^2~78^2~39 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1b9c332b6c92e992b1971a08412c6f460a54b514;p=firefly-linux-kernel-4.4.55.git Btrfs: only reserve space in fallocate if we have to do a preallocate Lukas found a problem where if he tries to fallocate over the same region twice and the first fallocate took up all the space we would fail with ENOSPC. This is because we reserve the total space we want to use for fallocate, regardless of wether or not we will have to actually preallocate. So instead move the check into the loop where we actually have to do the preallocate. Thanks, Tested-by: Lukas Czerner Signed-off-by: Josef Bacik --- diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index e4e57d59edb7..de569af766fe 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1615,10 +1615,6 @@ static long btrfs_fallocate(struct file *file, int mode, goto out; } - ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start); - if (ret) - goto out; - locked_end = alloc_end - 1; while (1) { struct btrfs_ordered_extent *ordered; @@ -1664,11 +1660,27 @@ static long btrfs_fallocate(struct file *file, int mode, if (em->block_start == EXTENT_MAP_HOLE || (cur_offset >= inode->i_size && !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { + + /* + * Make sure we have enough space before we do the + * allocation. + */ + ret = btrfs_check_data_free_space(inode, last_byte - + cur_offset); + if (ret) { + free_extent_map(em); + break; + } + ret = btrfs_prealloc_file_range(inode, mode, cur_offset, last_byte - cur_offset, 1 << inode->i_blkbits, offset + len, &alloc_hint); + + /* Let go of our reservation. */ + btrfs_free_reserved_data_space(inode, last_byte - + cur_offset); if (ret < 0) { free_extent_map(em); break; @@ -1694,8 +1706,6 @@ static long btrfs_fallocate(struct file *file, int mode, } unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end, &cached_state, GFP_NOFS); - - btrfs_free_reserved_data_space(inode, alloc_end - alloc_start); out: mutex_unlock(&inode->i_mutex); return ret;