From: Trond Myklebust <trond.myklebust@primarydata.com>
Date: Thu, 22 Sep 2016 17:38:53 +0000 (-0400)
Subject: NFSv4: Don't report revoked delegations as valid in nfs_have_delegation()
X-Git-Tag: firefly_0821_release~176^2~4^2~22^2~51
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=79e7e444ed6cc249208798d1effea31945719c10;p=firefly-linux-kernel-4.4.55.git

NFSv4: Don't report revoked delegations as valid in nfs_have_delegation()

commit b3f9e7239074613aa6bdafa4caf7c104fe1e7276 upstream.

If the delegation is revoked, then it can't be used for caching.

Fixes: 869f9dfa4d6d ("NFSv4: Fix races between nfs_remove_bad_delegation()...")
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 5166adcfc0fb..f73207409b2d 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -51,6 +51,7 @@ nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
 	rcu_read_lock();
 	delegation = rcu_dereference(NFS_I(inode)->delegation);
 	if (delegation != NULL && (delegation->type & flags) == flags &&
+	    !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
 	    !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
 		if (mark)
 			nfs_mark_delegation_referenced(delegation);