File 0020-drbd-do-not-allow-auto-demote-to-be-interrupted-by-s.patch of Package drbd

From c8e2a3c4355b4794267cd6e58a074802b4607cb9 Mon Sep 17 00:00:00 2001
From: Joel Colledge <joel.colledge@linbit.com>
Date: Fri, 22 Sep 2023 16:57:24 +0200
Subject: [PATCH 20/20] drbd: do not allow auto-demote to be interrupted by
 signal

Pending signals can mess up auto-demote:

drbd res: Preparing cluster-wide state change 671410162 (0->-1 3/2)
drbd res: Aborting cluster-wide state change 671410162 (6ms) rv = -21
drbd res: Auto-demote failed: Interrupted state change

After this state change failure no process has the DRBD device open, but
DRBD remains Primary.
---
 drbd/drbd_main.c | 33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/drbd/drbd_main.c b/drbd/drbd_main.c
index 1864861db21d..0719229f210e 100644
--- a/drbd/drbd_main.c
+++ b/drbd/drbd_main.c
@@ -2851,17 +2851,30 @@ static void drbd_release(struct gendisk *gd)
 	    !test_and_set_bit(DESTROYING_DEV, &device->flags))
 		call_rcu(&device->rcu, drbd_reclaim_device);
 
-	if (resource->res_opts.auto_promote) {
-		enum drbd_state_rv rv;
+	if (resource->res_opts.auto_promote &&
+			open_rw_cnt == 0 &&
+			resource->role[NOW] == R_PRIMARY &&
+			!test_bit(EXPLICIT_PRIMARY, &resource->flags)) {
+		sigset_t mask, oldmask;
+		int rv;
+
+		/*
+		 * Auto-demote is triggered by the last opener releasing the
+		 * DRBD device. However, it is an implicit action, so it should
+		 * not be affected by the state of the process. In particular,
+		 * it should ignore any pending signals. It may be the case
+		 * that the process is releasing DRBD because it is being
+		 * terminated using a signal.
+		 */
+		sigfillset(&mask);
+		sigprocmask(SIG_BLOCK, &mask, &oldmask);
 
-		if (was_writable && open_rw_cnt == 0 &&
-		    resource->role[NOW] == R_PRIMARY &&
-		    !test_bit(EXPLICIT_PRIMARY, &resource->flags)) {
-			rv = drbd_set_role(resource, R_SECONDARY, false, "auto-demote", NULL);
-			if (rv < SS_SUCCESS)
-				drbd_warn(resource, "Auto-demote failed: %s (%d)\n",
-					  drbd_set_st_err_str(rv), rv);
-		}
+		rv = drbd_set_role(resource, R_SECONDARY, false, "auto-demote", NULL);
+		if (rv < SS_SUCCESS)
+			drbd_warn(resource, "Auto-demote failed: %s (%d)\n",
+					drbd_set_st_err_str(rv), rv);
+
+		sigprocmask(SIG_SETMASK, &oldmask, NULL);
 	}
 
 	if (open_ro_cnt == 0 && open_rw_cnt == 0 && resource->fail_io[NOW]) {
-- 
2.35.3