The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
Thanks,
Sasha
------------------ original commit in Linus's tree ------------------
>From cd32b27a66db8776d8b8e82ec7d7dde97a8693b0 Mon Sep 17 00:00:00 2001
From: Yu Kuai <yukuai3@xxxxxxxxxx>
Date: Tue, 5 Mar 2024 15:23:03 +0800
Subject: [PATCH] md/dm-raid: don't call md_reap_sync_thread() directly
Currently md_reap_sync_thread() is called from raid_message() directly
without holding 'reconfig_mutex', this is definitely unsafe because
md_reap_sync_thread() can change many fields that is protected by
'reconfig_mutex'.
However, hold 'reconfig_mutex' here is still problematic because this
will cause deadlock, for example, commit 130443d60b1b ("md: refactor
idle/frozen_sync_thread() to fix deadlock").
Fix this problem by using stop_sync_thread() to unregister sync_thread,
like md/raid did.
Fixes: be83651f0050 ("DM RAID: Add message/status support for changing sync action")
Cc: stable@xxxxxxxxxxxxxxx # v6.7+
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Signed-off-by: Xiao Ni <xni@xxxxxxxxxx>
Acked-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Song Liu <song@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240305072306.2562024-7-yukuai1@xxxxxxxxxxxxxxx
---
drivers/md/dm-raid.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index e2d7a73c0f874..47c4b1b6e532a 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3719,6 +3719,7 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv,
{
struct raid_set *rs = ti->private;
struct mddev *mddev = &rs->md;
+ int ret = 0;
if (!mddev->pers || !mddev->pers->sync_request)
return -EINVAL;
@@ -3726,17 +3727,24 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv,
if (test_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags))
return -EBUSY;
- if (!strcasecmp(argv[0], "frozen"))
- set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
- else
- clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+ if (!strcasecmp(argv[0], "frozen")) {
+ ret = mddev_lock(mddev);
+ if (ret)
+ return ret;
- if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
- if (mddev->sync_thread) {
- set_bit(MD_RECOVERY_INTR, &mddev->recovery);
- md_reap_sync_thread(mddev);
- }
- } else if (decipher_sync_action(mddev, mddev->recovery) != st_idle)
+ md_frozen_sync_thread(mddev);
+ mddev_unlock(mddev);
+ } else if (!strcasecmp(argv[0], "idle")) {
+ ret = mddev_lock(mddev);
+ if (ret)
+ return ret;
+
+ md_idle_sync_thread(mddev);
+ mddev_unlock(mddev);
+ }
+
+ clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+ if (decipher_sync_action(mddev, mddev->recovery) != st_idle)
return -EBUSY;
else if (!strcasecmp(argv[0], "resync"))
; /* MD_RECOVERY_NEEDED set below */
--
2.43.0
