summary refs log tree commit diff
path: root/fs/nfs/delegation.c
diff options
context:
space:
mode:
authorTrond Myklebust <trond.myklebust@primarydata.com>2016-09-22 13:39:12 -0400
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2016-09-27 14:34:54 -0400
commitb1a318de9bc4946ad4a20481ab3ce28c2e8cd72c (patch)
treee130b82c8bb97e7eec1adba8dc4f06aa6958d343 /fs/nfs/delegation.c
parent9c27869d3f0680fa01d15616891a666d9e30fd83 (diff)
downloadlinux-b1a318de9bc4946ad4a20481ab3ce28c2e8cd72c.tar.gz
NFSv4: Fix a race in nfs_inode_reclaim_delegation()
If we race with a delegreturn before taking the spin lock, we
currently end up dropping the delegation stateid.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'fs/nfs/delegation.c')
-rw-r--r--fs/nfs/delegation.c12
1 files changed, 5 insertions, 7 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 5de4cfb2ab07..094e0efe6a82 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -195,15 +195,13 @@ void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
 			rcu_read_unlock();
 			put_rpccred(oldcred);
 			trace_nfs4_reclaim_delegation(inode, res->delegation_type);
-		} else {
-			/* We appear to have raced with a delegation return. */
-			spin_unlock(&delegation->lock);
-			rcu_read_unlock();
-			nfs_inode_set_delegation(inode, cred, res);
+			return;
 		}
-	} else {
-		rcu_read_unlock();
+		/* We appear to have raced with a delegation return. */
+		spin_unlock(&delegation->lock);
 	}
+	rcu_read_unlock();
+	nfs_inode_set_delegation(inode, cred, res);
 }
 
 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)