From: Benjamin Coddington <bcodding@redhat.com>
Date: Wed, 3 Mar 2021 08:47:16 -0500
Subject: [PATCH] SUNRPC: Set memalloc_nofs_save() for sync tasks
Git-commit: f0940f4b3284a00f38a5d42e6067c2aaa20e1f2e
Patch-mainline: v5.12-rc3
References: git-fixes

We could recurse into NFS doing memory reclaim while sending a sync task,
which might result in a deadlock.  Set memalloc_nofs_save for sync task
execution.

Fixes: a1231fda7e94 ("SUNRPC: Set memalloc_nofs_save() on all rpciod/xprtiod jobs")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 net/sunrpc/sched.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -983,8 +983,11 @@ void rpc_execute(struct rpc_task *task)
 
 	rpc_set_active(task);
 	rpc_make_runnable(rpciod_workqueue, task);
-	if (!is_async)
+	if (!is_async) {
+		unsigned int pflags = memalloc_nofs_save();
 		__rpc_execute(task);
+		memalloc_nofs_restore(pflags);
+	}
 }
 
 static void rpc_async_schedule(struct work_struct *work)