[3.16.y-ckt stable] Patch "NFSv4: Ensure that we remove NFSv4.0 delegations when state has expired" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    NFSv4: Ensure that we remove NFSv4.0 delegations when state has expired

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 2b6e15b3260d091bdb2a52240f62c83b2a3893a8 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust at primarydata.com>
Date: Fri, 17 Oct 2014 15:10:25 +0300
Subject: NFSv4: Ensure that we remove NFSv4.0 delegations when state has
 expired

commit 4dfd4f7af0afd201706ad186352ca423b0f17d4b upstream.

NFSv4.0 does not have TEST_STATEID/FREE_STATEID functionality, so
unlike NFSv4.1, the recovery procedure when stateids have expired or
have been revoked requires us to just forget the delegation.

http://lkml.kernel.org/r/CAN-5tyHwG=Cn2Q9KsHWadewjpTTy_K26ee+UnSvHvG4192p-Xw@mail.gmail.com
Signed-off-by: Trond Myklebust <trond.myklebust at primarydata.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/nfs/nfs4proc.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 43fd8c557fe9..fc97ec1f9037 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2094,6 +2094,28 @@ static int nfs4_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *sta
 	return ret;
 }

+static void nfs_finish_clear_delegation_stateid(struct nfs4_state *state)
+{
+	nfs_remove_bad_delegation(state->inode);
+	write_seqlock(&state->seqlock);
+	nfs4_stateid_copy(&state->stateid, &state->open_stateid);
+	write_sequnlock(&state->seqlock);
+	clear_bit(NFS_DELEGATED_STATE, &state->flags);
+}
+
+static void nfs40_clear_delegation_stateid(struct nfs4_state *state)
+{
+	if (rcu_access_pointer(NFS_I(state->inode)->delegation) != NULL)
+		nfs_finish_clear_delegation_stateid(state);
+}
+
+static int nfs40_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *state)
+{
+	/* NFSv4.0 doesn't allow for delegation recovery on open expire */
+	nfs40_clear_delegation_stateid(state);
+	return nfs4_open_expired(sp, state);
+}
+
 #if defined(CONFIG_NFS_V4_1)
 static void nfs41_clear_delegation_stateid(struct nfs4_state *state)
 {
@@ -8255,7 +8277,7 @@ static const struct nfs4_state_recovery_ops nfs41_reboot_recovery_ops = {
 static const struct nfs4_state_recovery_ops nfs40_nograce_recovery_ops = {
 	.owner_flag_bit = NFS_OWNER_RECLAIM_NOGRACE,
 	.state_flag_bit	= NFS_STATE_RECLAIM_NOGRACE,
-	.recover_open	= nfs4_open_expired,
+	.recover_open	= nfs40_open_expired,
 	.recover_lock	= nfs4_lock_expired,
 	.establish_clid = nfs4_init_clientid,
 };
--
2.1.0