Patch "nfsd: deal with revoked delegations appropriately" has been added to the 3.18-stable tree

[<gregkh@linuxfoundation.org>]

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

    nfsd: deal with revoked delegations appropriately

to the 3.18-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:
     nfsd-deal-with-revoked-delegations-appropriately.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 95da1b3a5aded124dd1bda1e3cdb876184813140 Mon Sep 17 00:00:00 2001
From: Andrew Elble <aweits@rit.edu>
Date: Fri, 3 Nov 2017 14:06:31 -0400
Subject: nfsd: deal with revoked delegations appropriately

From: Andrew Elble <aweits@rit.edu>

commit 95da1b3a5aded124dd1bda1e3cdb876184813140 upstream.

If a delegation has been revoked by the server, operations using that
delegation should error out with NFS4ERR_DELEG_REVOKED in the >4.1
case, and NFS4ERR_BAD_STATEID otherwise.

The server needs NFSv4.1 clients to explicitly free revoked delegations.
If the server returns NFS4ERR_DELEG_REVOKED, the client will do that;
otherwise it may just forget about the delegation and be unable to
recover when it later sees SEQ4_STATUS_RECALLABLE_STATE_REVOKED set on a
SEQUENCE reply.  That can cause the Linux 4.1 client to loop in its
stage manager.

Signed-off-by: Andrew Elble <aweits@rit.edu>
Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/nfsd/nfs4state.c |   25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3602,7 +3602,8 @@ static struct nfs4_delegation *find_dele
 {
 	struct nfs4_stid *ret;
 
-	ret = find_stateid_by_type(cl, s, NFS4_DELEG_STID);
+	ret = find_stateid_by_type(cl, s,
+				NFS4_DELEG_STID|NFS4_REVOKED_DELEG_STID);
 	if (!ret)
 		return NULL;
 	return delegstateid(ret);
@@ -3625,6 +3626,12 @@ nfs4_check_deleg(struct nfs4_client *cl,
 	deleg = find_deleg_stateid(cl, &open->op_delegate_stateid);
 	if (deleg == NULL)
 		goto out;
+	if (deleg->dl_stid.sc_type == NFS4_REVOKED_DELEG_STID) {
+		nfs4_put_stid(&deleg->dl_stid);
+		if (cl->cl_minorversion)
+			status = nfserr_deleg_revoked;
+		goto out;
+	}
 	flags = share_access_to_flags(open->op_share_access);
 	status = nfs4_check_delegmode(deleg, flags);
 	if (status) {
@@ -4451,6 +4458,16 @@ nfsd4_lookup_stateid(struct nfsd4_compou
 		     struct nfs4_stid **s, struct nfsd_net *nn)
 {
 	__be32 status;
+	bool return_revoked = false;
+
+	/*
+	 *  only return revoked delegations if explicitly asked.
+	 *  otherwise we report revoked or bad_stateid status.
+	 */
+	if (typemask & NFS4_REVOKED_DELEG_STID)
+		return_revoked = true;
+	else if (typemask & NFS4_DELEG_STID)
+		typemask |= NFS4_REVOKED_DELEG_STID;
 
 	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid))
 		return nfserr_bad_stateid;
@@ -4465,6 +4482,12 @@ nfsd4_lookup_stateid(struct nfsd4_compou
 	*s = find_stateid_by_type(cstate->clp, stateid, typemask);
 	if (!*s)
 		return nfserr_bad_stateid;
+	if (((*s)->sc_type == NFS4_REVOKED_DELEG_STID) && !return_revoked) {
+		nfs4_put_stid(*s);
+		if (cstate->minorversion)
+			return nfserr_deleg_revoked;
+		return nfserr_bad_stateid;
+	}
 	return nfs_ok;
 }
 


Patches currently in stable-queue which might be from aweits@rit.edu are

queue-3.18/nfsd-deal-with-revoked-delegations-appropriately.patch