[PATCH 4.19 146/321] dm raid: fix false -EBUSY when handling check/repair message

Greg Kroah-Hartman
2019-12-03T23:04:42Z

From: Heinz Mauelshagen <heinzm@redhat.com>

[ Upstream commit 74694bcbdf7e28a5ad548cdda9ac56d30be00d13 ]

Sending a check/repair message infrequently leads to -EBUSY instead of
properly identifying an active resync. This occurs because
raid_message() is testing recovery bits in a racy way.

Fix by calling decipher_sync_action() from raid_message() to properly
identify the idle state of the RAID device.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/md/dm-raid.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 6c9b542882613..23de59a692c51 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3690,8 +3690,7 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv,
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_reap_sync_thread(mddev);
}
- } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
- test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
+ } else if (decipher_sync_action(mddev, mddev->recovery) != st_idle)
return -EBUSY;
else if (!strcasecmp(argv[0], "resync"))
; /* MD_RECOVERY_NEEDED set below */
--
2.20.1