From d39f0010e40964d959c5157be02839da8a178015 Mon Sep 17 00:00:00 2001
From: Heinz Mauelshagen <heinzm@redhat.com>
Date: Sat, 2 Dec 2017 01:03:52 +0100
Subject: [PATCH] dm raid: fix raid_resume() to keep raid set frozen as needed
Git-commit: d39f0010e40964d959c5157be02839da8a178015
Patch-mainline: v4.16-rc1
References: bsc#1093023

During a reshape request: if userspace reloads a "raid" table multiple
times, resulting in multiple superblock reads, the raid set needs to
stay frozen until all config changes (chunk size, layout data_offset,
delta_disks) have been stored in the superblocks and respective flags
cleared.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Coly Li <colyli@suse.de>

---
 drivers/md/dm-raid.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 2bb0ac7c3fba..bf3c9e3c736d 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3899,7 +3899,7 @@ static int raid_preresume(struct dm_target *ti)
 	}
 
 	/* Check for any reshape request unless new raid set */
-	if (test_and_clear_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
+	if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
 		/* Initiate a reshape. */
 		rs_set_rdev_sectors(rs);
 		mddev_lock_nointr(mddev);
@@ -3941,8 +3941,14 @@ static void raid_resume(struct dm_target *ti)
 	 * This ensures that the constructor for the inactive table
 	 * retrieves an up-to-date reshape_position.
 	 */
-	if (!(rs->ctr_flags & RESUME_STAY_FROZEN_FLAGS))
-		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+	if (!test_and_clear_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags) &&
+	    !(rs->ctr_flags & RESUME_STAY_FROZEN_FLAGS)) {
+		if (rs_is_reshapable(rs)) {
+			if (!rs_is_reshaping(rs) || _get_reshape_sectors(rs))
+				clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+		} else
+			clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+	}
 
 	if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
 		mddev_lock_nointr(mddev);
-- 
2.16.3