Patch "NFSv4.1 fix infinite loop on IO BAD_STATEID error" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

NFSv4.1 fix infinite loop on IO BAD_STATEID error

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
nfsv4.1-fix-infinite-loop-on-io-bad_stateid-error.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Olga Kornievskaia <[email protected]>
Date: Thu, 30 Mar 2017 13:49:03 -0400
Subject: NFSv4.1 fix infinite loop on IO BAD_STATEID error

From: Olga Kornievskaia <[email protected]>

commit 0e3d3e5df07dcf8a50d96e0ecd6ab9a888f55dfc upstream.

Commit 63d63cbf5e03 "NFSv4.1: Don't recheck delegations that have already been checked" introduced a regression where when a client received BAD_STATEID error it would not send any TEST_STATEID and instead go into an infinite loop of resending the IO that caused the BAD_STATEID.

---
 fs/nfs/nfs4proc.c |    9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

@@ -2532,17 +2532,14 @@ static void nfs41_check_delegation_state
 	}
 
 	nfs4_stateid_copy(&stateid, &delegation->stateid);
-	if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
+	if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) ||
+		!test_and_clear_bit(NFS_DELEGATION_TEST_EXPIRED,
+			&delegation->flags)) {
 		rcu_read_unlock();
 		nfs_finish_clear_delegation_stateid(state, &stateid);
 		return;
 	}
 
-	if (!test_and_clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags)) {
-		rcu_read_unlock();
-		return;
-	}
-
 	cred = get_rpccred(delegation->cred);
 	rcu_read_unlock();
 	status = nfs41_test_and_free_expired_stateid(server, &stateid, cred);

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/nfsv4.1-fix-infinite-loop-on-io-bad_stateid-error.patch