From: Qu Wenruo wqu@suse.com
[ Upstream commit fbf48bb0b197e6894a04c714728c952af7153bf3 ]
There is a piece of weird code in insert_prealloc_file_extent(), which looks like:
ret = btrfs_qgroup_release_data(inode, file_offset, len); if (ret < 0) return ERR_PTR(ret); if (trans) { ret = insert_reserved_file_extent(trans, inode, file_offset, &stack_fi, true, ret); ... } extent_info.is_new_extent = true; extent_info.qgroup_reserved = ret; ...
Note how the variable @ret is abused here, and if anyone is adding code just after btrfs_qgroup_release_data() call, it's super easy to overwrite the @ret and cause tons of qgroup related bugs.
Fix such abuse by introducing new variable @qgroup_released, so that we won't reuse the existing variable @ret.
Signed-off-by: Qu Wenruo wqu@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/inode.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 9b4f75568261..8f36071769fa 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9674,6 +9674,7 @@ static struct btrfs_trans_handle *insert_prealloc_file_extent( struct btrfs_path *path; u64 start = ins->objectid; u64 len = ins->offset; + int qgroup_released; int ret;
memset(&stack_fi, 0, sizeof(stack_fi)); @@ -9686,14 +9687,14 @@ static struct btrfs_trans_handle *insert_prealloc_file_extent( btrfs_set_stack_file_extent_compression(&stack_fi, BTRFS_COMPRESS_NONE); /* Encryption and other encoding is reserved and all 0 */
- ret = btrfs_qgroup_release_data(inode, file_offset, len); - if (ret < 0) - return ERR_PTR(ret); + qgroup_released = btrfs_qgroup_release_data(inode, file_offset, len); + if (qgroup_released < 0) + return ERR_PTR(qgroup_released);
if (trans) { ret = insert_reserved_file_extent(trans, inode, file_offset, &stack_fi, - true, ret); + true, qgroup_released); if (ret) return ERR_PTR(ret); return trans; @@ -9706,7 +9707,7 @@ static struct btrfs_trans_handle *insert_prealloc_file_extent( extent_info.file_offset = file_offset; extent_info.extent_buf = (char *)&stack_fi; extent_info.is_new_extent = true; - extent_info.qgroup_reserved = ret; + extent_info.qgroup_reserved = qgroup_released; extent_info.insertions = 0;
path = btrfs_alloc_path();