6.12-stable review patch. If anyone has any objections, please let me know.
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From: Xiao Ni xni@redhat.com
commit fa1944bbe6220eb929e2c02e5e8706b908565711 upstream.
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 xni@redhat.com Reviewed-by: Yu Kuai yukuai3@huawei.com Link: https://lore.kernel.org/r/20241106095124.74577-1-xni@redhat.com Signed-off-by: Song Liu song@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/raid5.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7177,6 +7177,8 @@ raid5_store_group_thread_cnt(struct mdde err = mddev_suspend_and_lock(mddev); if (err) return err; + raid5_quiesce(mddev, true); + conf = mddev->private; if (!conf) err = -ENODEV; @@ -7198,6 +7200,8 @@ raid5_store_group_thread_cnt(struct mdde kfree(old_groups); } } + + raid5_quiesce(mddev, false); mddev_unlock_and_resume(mddev);
return err ?: len;