From af560e357a81964544be40c549e241b032ef7565 Mon Sep 17 00:00:00 2001 From: Li Youhong Date: Tue, 29 Sep 2026 16:39:16 +0800 Subject: [PATCH] md/raid5: drain released_stripes before destroying the cache grow_one_stripe() calls raid5_release_stripe() for each new stripe. When mddev->thread is already set, that queues the stripe on conf->released_stripes and wakes the thread. Only raid5d moves that list onto inactive_list. Takeover calls setup_conf() while mddev->thread still belongs to the previous personality, so those stripes stay on released_stripes. If setup_conf() then fails, shrink_stripes() only frees inactive_list and kmem_cache_destroy() warns that objects remain. Move stripes still queued on released_stripes onto inactive_list before shrink_stripes() frees them. Fixes: 773ca82fa1ee ("raid5: make release_stripe lockless") Reported-by: syzbot+6a132745caefcf42cb0d@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-raid/6ab6b743.7eec07f4.c25c.0006.GAE@google.com/T/#t Signed-off-by: Li Youhong Link: https://patch.msgid.link/20260929083916.50620-1-dayou5941@163.com Signed-off-by: Yu Kuai --- drivers/md/raid5.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index c8ea9ba6829e..d52adf81065a 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2713,6 +2713,37 @@ static int drop_one_stripe(struct r5conf *conf) static void shrink_stripes(struct r5conf *conf) { + struct list_head temp[NR_STRIPE_HASH_LOCKS]; + int i; + + /* + * grow_one_stripe() parks new stripes on released_stripes when + * mddev->thread is already set. Takeover leaves the previous + * personality's thread there, so raid5d never moves them to + * inactive_list. Drain them before the cache is destroyed. + * slab_cache is assigned only after device_lock and the hash + * lists exist; earlier abort paths have nothing to drain. + */ + if (conf->slab_cache) { + for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++) + INIT_LIST_HEAD(&temp[i]); + + spin_lock_irq(&conf->device_lock); + release_stripe_list(conf, temp); + spin_unlock_irq(&conf->device_lock); + + for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++) { + if (list_empty(&temp[i])) + continue; + spin_lock_irq(conf->hash_locks + i); + if (list_empty(conf->inactive_list + i)) + atomic_dec(&conf->empty_inactive_list_nr); + list_splice_tail_init(&temp[i], + conf->inactive_list + i); + spin_unlock_irq(conf->hash_locks + i); + } + } + while (conf->max_nr_stripes && drop_one_stripe(conf)) ;