From: Trond Myklebust <trond.myklebust@primarydata.com>
Date: Fri, 27 Feb 2015 19:25:50 +0000 (-0500)
Subject: NFSv4: Ensure we honour NFS_DELEGATION_RETURNING in nfs_inode_set_delegation()
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ade04647dd56881e285983af3db702d56ee97e86;p=linux-beck.git

NFSv4: Ensure we honour NFS_DELEGATION_RETURNING in nfs_inode_set_delegation()

Ensure that nfs_inode_set_delegation() doesn't inadvertently detach a
delegation that is already in the process of being returned.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index d9caf73eef48..5ca502b5f877 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -370,7 +370,10 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct
 			delegation = NULL;
 			goto out;
 		}
-		freeme = nfs_detach_delegation_locked(nfsi, 
+		if (test_and_set_bit(NFS_DELEGATION_RETURNING,
+					&old_delegation->flags))
+			goto out;
+		freeme = nfs_detach_delegation_locked(nfsi,
 				old_delegation, clp);
 		if (freeme == NULL)
 			goto out;