Btrfs: fix transaction handle leak on failure to create hard link

If we failed to create a hard link we were not always releasing the
the transaction handle we got before, resulting in a memory leak and
preventing any other tasks from being able to commit the current
transaction.
Fix this by always releasing our transaction handle.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5dbc07a7c220..018c2a6108f2 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6488,7 +6488,7 @@ out_unlock_inode:
 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
                       struct dentry *dentry)
 {
-        struct btrfs_trans_handle *trans;
+        struct btrfs_trans_handle *trans = NULL;
         struct btrfs_root *root = BTRFS_I(dir)->root;
         struct inode *inode = d_inode(old_dentry);
         u64 index;
@@ -6514,6 +6514,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
         trans = btrfs_start_transaction(root, 5);
         if (IS_ERR(trans)) {
                 err = PTR_ERR(trans);
+                trans = NULL;
                 goto fail;
         }
 
@@ -6547,9 +6548,10 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
                 btrfs_log_new_name(trans, inode, NULL, parent);
         }
 
-        btrfs_end_transaction(trans, root);
         btrfs_balance_delayed_items(root);
 fail:
+        if (trans)
+                btrfs_end_transaction(trans, root);
         if (drop_inode) {
                 inode_dec_link_count(inode);
                 iput(inode);