From: Robbie Ko robbieko@synology.com
[ Upstream commit 39ad317315887c2cb9a4347a93a8859326ddf136 ]
When doing fallocate, we first add the range to the reserve_list and then reserve the quota. If quota reservation fails, we'll release all reserved parts of reserve_list.
However, cur_offset is not updated to indicate that this range is already been inserted into the list. Therefore, the same range is freed twice. Once at list_for_each_entry loop, and once at the end of the function. This will result in WARN_ON on bytes_may_use when we free the remaining space.
At the end, under the 'out' label we have a call to:
btrfs_free_reserved_data_space(inode, data_reserved, alloc_start, alloc_end - cur_offset);
The start offset, third argument, should be cur_offset.
Everything from alloc_start to cur_offset was freed by the list_for_each_entry_safe_loop.
Fixes: 18513091af94 ("btrfs: update btrfs_space_info's bytes_may_use timely") Reviewed-by: Filipe Manana fdmanana@suse.com Signed-off-by: Robbie Ko robbieko@synology.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/file.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index ca4902c66dc43..868da8566f84c 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -3151,6 +3151,7 @@ static long btrfs_fallocate(struct file *file, int mode, ret = btrfs_qgroup_reserve_data(inode, &data_reserved, cur_offset, last_byte - cur_offset); if (ret < 0) { + cur_offset = last_byte; free_extent_map(em); break; } @@ -3200,7 +3201,7 @@ static long btrfs_fallocate(struct file *file, int mode, /* Let go of our reservation. */ if (ret != 0 && !(mode & FALLOC_FL_ZERO_RANGE)) btrfs_free_reserved_data_space(inode, data_reserved, - alloc_start, alloc_end - cur_offset); + cur_offset, alloc_end - cur_offset); extent_changeset_free(data_reserved); return ret; }