From: Xiao Ni Date: Wed, 6 Nov 2024 09:51:24 +0000 (+0800) Subject: md/raid5: Wait sync io to finish before changing group cnt X-Git-Tag: v6.13-rc1~211^2~28^2~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fa1944bbe6220eb929e2c02e5e8706b908565711;p=thirdparty%2Fkernel%2Flinux.git md/raid5: Wait sync io to finish before changing group cnt One customer reports a bug: raid5 is hung when changing thread cnt while resync is running. The stripes are all in conf->handle_list and new threads can't handle them. Commit b39f35ebe86d ("md: don't quiesce in mddev_suspend()") removes pers->quiesce from mddev_suspend/resume. Before this patch, mddev_suspend needs to wait for all ios including sync io to finish. Now it's used to only wait normal io. Fix this by calling raid5_quiesce from raid5_store_group_thread_cnt directly to wait all sync requests to finish before changing the group cnt. Fixes: b39f35ebe86d ("md: don't quiesce in mddev_suspend()") Cc: stable@vger.kernel.org Signed-off-by: Xiao Ni Reviewed-by: Yu Kuai Link: https://lore.kernel.org/r/20241106095124.74577-1-xni@redhat.com Signed-off-by: Song Liu --- diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index f5ac81dd21b2b..f09e7677ee9f1 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7176,6 +7176,8 @@ raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len) err = mddev_suspend_and_lock(mddev); if (err) return err; + raid5_quiesce(mddev, true); + conf = mddev->private; if (!conf) err = -ENODEV; @@ -7197,6 +7199,8 @@ raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len) kfree(old_groups); } } + + raid5_quiesce(mddev, false); mddev_unlock_and_resume(mddev); return err ?: len;