[PATCH 6.1 27/69] btrfs: fix reservation leak in some error paths when inserting inline extent

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Filipe Manana <fdmanana@suse.com>

[ Upstream commit c1c050f92d8f6aac4e17f7f2230160794fceef0c ]

If we fail to allocate a path or join a transaction, we return from
__cow_file_range_inline() without freeing the reserved qgroup data,
resulting in a leak. Fix this by ensuring we call btrfs_qgroup_free_data()
in such cases.

Signed-off-by: Filipe Manana <fdmanana@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 | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 78cd7b8ccfc85..c409fb3e55bf8 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -397,7 +397,7 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 size,
 	struct btrfs_drop_extents_args drop_args = { 0 };
 	struct btrfs_root *root = inode->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_trans_handle *trans;
+	struct btrfs_trans_handle *trans = NULL;
 	u64 data_len = (compressed_size ?: size);
 	int ret;
 	struct btrfs_path *path;
@@ -415,13 +415,16 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 size,
 		return 1;
 
 	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
+	if (!path) {
+		ret = -ENOMEM;
+		goto out;
+	}
 
 	trans = btrfs_join_transaction(root);
 	if (IS_ERR(trans)) {
-		btrfs_free_path(path);
-		return PTR_ERR(trans);
+		ret = PTR_ERR(trans);
+		trans = NULL;
+		goto out;
 	}
 	trans->block_rsv = &inode->block_rsv;
 
@@ -468,7 +471,8 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 size,
 	 */
 	btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE, NULL);
 	btrfs_free_path(path);
-	btrfs_end_transaction(trans);
+	if (trans)
+		btrfs_end_transaction(trans);
 	return ret;
 }
 
-- 
2.51.0