Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/kernel/fs/nfs/pnfs.c b/kernel/fs/nfs/pnfs.c
index bec038449..3cae0726c 100644
--- a/kernel/fs/nfs/pnfs.c
+++ b/kernel/fs/nfs/pnfs.c
@@ -365,6 +365,9 @@ pnfs_layout_need_return(struct pnfs_layout_hdr *lo,
 static bool
 pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo)
 {
+	/* Serialise LAYOUTGET/LAYOUTRETURN */
+	if (atomic_read(&lo->plh_outstanding) != 0)
+		return false;
 	if (test_and_set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
 		return false;
 	lo->plh_return_iomode = 0;
@@ -1182,13 +1185,11 @@ bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
 	 * i_lock */
         spin_lock(&ino->i_lock);
         lo = nfsi->layout;
-        if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
+        if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
+                rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
                 sleep = true;
+	}
         spin_unlock(&ino->i_lock);
-
-        if (sleep)
-                rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
-
         return sleep;
 }
 
@@ -1530,6 +1531,7 @@ pnfs_update_layout(struct inode *ino,
 		goto out;
 
 lookup_again:
+	nfs4_client_recover_expired_lease(clp);
 	first = false;
 	spin_lock(&ino->i_lock);
 	lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);