From ae89fd3de4793c0dc2ec7e9f26b58a357d74a6c7 Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka@redhat.com>
Date: Wed, 18 Oct 2017 19:01:11 -0400
Subject: [PATCH] md: use TASK_IDLE instead of blocking signals
Git-commit: ae89fd3de4793c0dc2ec7e9f26b58a357d74a6c7
Patch-mainline: v4.15-rc1
References: bsc#1093023

Hi - I submit this patch for the next merge window:

Some times ago, I made a patch f9c79bc05a2a that blocks signals around the
schedule() calls in MD. The MD subsystem needs to do an uninterruptible
sleep that is not accounted in load average - so we block signals and use
interruptible sleep.

The kernel has a special TASK_IDLE state for this purpose, so we can use
it instead of blocking signals. This patch doesn't fix any bug, it just
makes the code simpler.

(Coly Li: still keep including linux/sched/signal.h to keep KABI
 consistency)

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Coly Li <colyli@suse.de>

---
 drivers/md/raid1.c |    6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1320,18 +1320,14 @@ static void raid1_write_request(struct m
 		 */
 		DEFINE_WAIT(w);
 		for (;;) {
-			sigset_t full, old;
 			prepare_to_wait(&conf->wait_barrier,
-					&w, TASK_INTERRUPTIBLE);
+					&w, TASK_IDLE);
 			if (!mddev_is_clustered(mddev) ||
 			    !md_cluster_ops->area_resyncing(mddev, WRITE,
 							bio->bi_iter.bi_sector,
 							bio_end_sector(bio)))
 				break;
-			sigfillset(&full);
-			sigprocmask(SIG_BLOCK, &full, &old);
 			schedule();
-			sigprocmask(SIG_SETMASK, &old, NULL);
 		}
 		finish_wait(&conf->wait_barrier, &w);
 	}