[PATCH -next 6/6] md: enhance checking in md_check_recovery()
From: Yu Kuai <hidden>
Date: 2023-03-22 06:44:43
Also in:
lkml
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
From: Yu Kuai <redacted> 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 raid. This patch add a WARN_ON_ONCE() in the above corruption, and make sure md_check_recovery() won't register new sync_thread if 'MD_RECOVERY_RUNING' is still set. Signed-off-by: Yu Kuai <redacted> --- 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 cabdfd4ec001..048ec21932e9 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c@@ -9377,16 +9377,24 @@ 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". */
--
2.31.1