Patch "NFSv4.1: Fix a deadlock in layoutget" has been added to the 4.9-stable tree

Patch "NFSv4.1: Fix a deadlock in layoutget" has been added to the 4.9-stable tree

[gregkh]

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

    NFSv4.1: Fix a deadlock in layoutget

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-a-deadlock-in-layoutget.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 <stable@vger.kernel.org> know about it.


>From 8ac092519ad91931c96d306c4bfae2c6587c325f Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@primarydata.com>
Date: Mon, 23 Jan 2017 22:44:12 -0500
Subject: NFSv4.1: Fix a deadlock in layoutget

From: Trond Myklebust <trond.myklebust@primarydata.com>

commit 8ac092519ad91931c96d306c4bfae2c6587c325f upstream.

We cannot call nfs4_handle_exception() without first ensuring that the
slot has been freed. If not, we end up deadlocking with the process
waiting for recovery to complete, and recovery waiting for the slot
table to drain.

Fixes: 2e80dbe7ac51 ("NFSv4.1: Close callback races for OPEN, LAYOUTGET...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/nfs/nfs4proc.c |    1 +
 1 file changed, 1 insertion(+)

--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -8371,6 +8371,7 @@ nfs4_layoutget_handle_exception(struct r
 		goto out;
 	}
 
+	nfs4_sequence_free_slot(&lgp->res.seq_res);
 	err = nfs4_handle_exception(server, nfs4err, exception);
 	if (!status) {
 		if (exception->retry)


Patches currently in stable-queue which might be from trond.myklebust@primarydata.com are

queue-4.9/nfsv4.0-always-send-mode-in-setattr-after-exclusive4.patch
queue-4.9/sunrpc-cleanup-ida-information-when-removing-sunrpc-module.patch
queue-4.9/nfsv4.1-fix-a-deadlock-in-layoutget.patch
queue-4.9/nfs-don-t-increment-lock-sequence-id-after-nfs4err_moved.patch