Messages in this thread Patch in this message | | | From | Yu Kuai <> | Subject | [PATCH v2 07/11] md/dm-raid: don't call md_reap_sync_thread() directly | Date | Wed, 24 Jan 2024 17:14:17 +0800 |
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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") Signed-off-by: Yu Kuai <yukuai3@huawei.com> --- 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 5ce3c6020b1b..6b6c011d9f69 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 */ -- 2.39.2
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