Patch "pNFS: Handle NFS4ERR_RECALLCONFLICT correctly in LAYOUTGET" has been added to the 4.7-stable tree

[<gregkh@linuxfoundation.org>]

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

    pNFS: Handle NFS4ERR_RECALLCONFLICT correctly in LAYOUTGET

to the 4.7-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:
     pnfs-handle-nfs4err_recallconflict-correctly-in-layoutget.patch
and it can be found in the queue-4.7 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 66b53f325876703b7ab815c482cd104609f8772c Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@primarydata.com>
Date: Thu, 14 Jul 2016 14:28:31 -0400
Subject: pNFS: Handle NFS4ERR_RECALLCONFLICT correctly in LAYOUTGET

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

commit 66b53f325876703b7ab815c482cd104609f8772c upstream.

Instead of giving up altogether and falling back to doing I/O
through the MDS, which may make the situation worse, wait for
2 lease periods for the callback to resolve itself, and then
try destroying the existing layout.

Only if this was an attempt at getting a first layout, do we
give up altogether, as the server is clearly crazy.

Fixes: 183d9e7b112aa ("pnfs: rework LAYOUTGET retry handling")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/nfs/pnfs.c |   13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1505,7 +1505,7 @@ pnfs_update_layout(struct inode *ino,
 	struct pnfs_layout_segment *lseg = NULL;
 	nfs4_stateid stateid;
 	long timeout = 0;
-	unsigned long giveup = jiffies + rpc_get_timeout(server->client);
+	unsigned long giveup = jiffies + (clp->cl_lease_time << 1);
 	bool first;
 
 	if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
@@ -1649,9 +1649,18 @@ lookup_again:
 	if (IS_ERR(lseg)) {
 		switch(PTR_ERR(lseg)) {
 		case -EBUSY:
-		case -ERECALLCONFLICT:
 			if (time_after(jiffies, giveup))
 				lseg = NULL;
+			break;
+		case -ERECALLCONFLICT:
+			/* Huh? We hold no layouts, how is there a recall? */
+			if (first) {
+				lseg = NULL;
+				break;
+			}
+			/* Destroy the existing layout and start over */
+			if (time_after(jiffies, giveup))
+				pnfs_destroy_layout(NFS_I(ino));
 			/* Fallthrough */
 		case -EAGAIN:
 			break;


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

queue-4.7/nfs-don-t-create-zero-length-requests.patch
queue-4.7/pnfs-separate-handling-of-nfs4err_layouttrylater-and-recallconflict.patch
queue-4.7/pnfs-handle-nfs4err_recallconflict-correctly-in-layoutget.patch
queue-4.7/pnfs-fix-layoutget-handling-of-nfs4err_bad_stateid-and-nfs4err_expired.patch
queue-4.7/pnfs-fix-post-layoutget-error-handling-in-pnfs_update_layout.patch