From f71209b1f21c838a973d858d9f6f76cd39227733 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Mon, 29 May 2023 21:20:37 +0800 Subject: [PATCH] md: enhance checking in md_check_recovery() For md_check_recovery(): 1) if 'MD_RECOVERY_RUNING' is not set, register new sync_thread. 2) if 'MD_RECOVERY_RUNING' is set: a) if 'MD_RECOVERY_DONE' is not set, don't do anything, wait for md_do_sync() to be done. b) if 'MD_RECOVERY_DONE' is set, unregister sync_thread. Current code expects that sync_thread is not NULL, otherwise new sync_thread will be registered, which will corrupt the array. Make sure md_check_recovery() won't register new sync_thread if 'MD_RECOVERY_RUNING' is still set, and a new WARN_ON_ONCE() is added for the above corruption, Signed-off-by: Yu Kuai Reviewed-by: Xiao Ni Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20230529132037.2124527-7-yukuai1@huaweicloud.com --- drivers/md/md.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index e0d8e75..320d715 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -9388,16 +9388,24 @@ void md_check_recovery(struct mddev *mddev) if (mddev->sb_flags) md_update_sb(mddev, 0); - if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) && - !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) { - /* resync/recovery still happening */ - clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery); - goto unlock; - } - if (mddev->sync_thread) { + /* + * Never start a new sync thread if MD_RECOVERY_RUNNING is + * still set. + */ + if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) { + if (!test_bit(MD_RECOVERY_DONE, &mddev->recovery)) { + /* resync/recovery still happening */ + clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery); + goto unlock; + } + + if (WARN_ON_ONCE(!mddev->sync_thread)) + goto unlock; + md_reap_sync_thread(mddev); goto unlock; } + /* Set RUNNING before clearing NEEDED to avoid * any transients in the value of "sync_action". */ -- 2.7.4