[PATCH] md/raid1: don't set array_frozen in raid1_takeover()

[Bruce Johnston <bjohnsto@redhat.com>]

raid1_takeover() sets conf->array_frozen = 1 on the newly-allocated
r1conf and nothing ever clears it, so every I/O to the array stalls
permanently once _wait_barrier() sees it stuck at 1.

This used to be harmless: level_store() called mddev_resume() right
after pers->run(), which called raid1_quiesce(mddev, 0) and cleared
array_frozen back to 0 regardless of what raid1_takeover() set. Commit
b39f35ebe86d ("md: don't quiesce in mddev_suspend()") removed that
quiesce(mddev, 0) call, so the pre-set now sticks.

setup_conf() already zero-initializes the new r1conf via kzalloc, so
just don't set array_frozen here.

Same class of bug as commit 892da88d1cd9 ("md/raid10: fix a
'conf->barrier' leakage in raid10_takeover()"), also triggered by
b39f35ebe86d.

Fixes: b39f35ebe86d ("md: don't quiesce in mddev_suspend()")
Link: https://issues.redhat.com/browse/RHEL-191802
Signed-off-by: Bruce Johnston <bjohnsto@redhat.com>
---
 drivers/md/raid1.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index afe2ca96a..2a247ed5f 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -3485,8 +3485,6 @@ static void *raid1_takeover(struct mddev *mddev)
 		mddev->new_chunk_sectors = 0;
 		conf = setup_conf(mddev);
 		if (!IS_ERR(conf)) {
-			/* Array must appear to be quiesced */
-			conf->array_frozen = 1;
 			mddev_clear_unsupported_flags(mddev,
 				UNSUPPORTED_MDDEV_FLAGS);
 		}
-- 
2.54.0