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>
(cherry picked from commit ca003b4cbeb0149b9814d86589ec61072bd7c16d)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 0a22923dca77bf16bf1972be929a6dec03c106d1..6db137acd3b90a580070947824eea641aa7d4988 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6413,7 +6413,7 @@ 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;
@@ -6439,6 +6439,7 @@ 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;
        }
 
@@ -6472,9 +6473,10 @@ 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);