From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4929E1DACB1 for ; Wed, 30 Apr 2025 04:36:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745987771; cv=none; b=A2krK/D+2b3Zdo+2eMC6yzYM1/a7Q1WUCr75Wmy67Z5braffZEJOwv6m3rvDqU0acH7UtVfYtcCNnI6lzup49qdHYNdJeOt1YKnjGjJdHttnz0qN5jGJahDfVyKoYLreATR0W1iXSabA85pDd51qEe47qRGWflPd0Hc+9vt09V8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745987771; c=relaxed/simple; bh=8/T3fsRFfz8WcAjHXqWdqFFzTHY1sQa00VVvvgDU0Q8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oHhgHNLmaVz8QqiHxEtHFsd2dztZlhUlpGvc4YO+7hHD6m0B8PUtQPNFtk/9GDoUpkgPOys4SNVB68hiUHcRJ8tJ9CXe+iByPXO4lBzZi0L1UUiuQmie9fcPhwH8jUfIP2XNG6pq4boCDKj32rhJmlcHObJd8fGjlZsghvvdSwM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=WVbXMxS/; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WVbXMxS/" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1745987768; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Zmlmp60GPfqdAwfKgwoVfkVf4xNsEU2fUKb+WpoCLNo=; b=WVbXMxS/I/tgst8jHYXUM2nWxaBhnDsc+9CxPekE9hju+3I6Ei99Nc93M/BmM8Kg+s5i8b TYF3XdhiL9gGRLdPpnLmksLN2ytzZEHDVDenlHC4R/QzIQ+I1qFRO+mSQvs/ujbZOk9ogj jJmx48Cw6GHKvx6OED2WU3UqdG7WLx0= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-369-Ucj4kZxFPea80yeWPciggA-1; Wed, 30 Apr 2025 00:36:06 -0400 X-MC-Unique: Ucj4kZxFPea80yeWPciggA-1 X-Mimecast-MFC-AGG-ID: Ucj4kZxFPea80yeWPciggA_1745987765 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id DE7461956096; Wed, 30 Apr 2025 04:36:04 +0000 (UTC) Received: from localhost (unknown [10.72.116.48]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id CCFE118001D5; Wed, 30 Apr 2025 04:36:03 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org Cc: Nilay Shroff , Shinichiro Kawasaki , =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= , Christoph Hellwig , Ming Lei , Hannes Reinecke Subject: [PATCH V4 07/24] block: prevent adding/deleting disk during updating nr_hw_queues Date: Wed, 30 Apr 2025 12:35:09 +0800 Message-ID: <20250430043529.1950194-8-ming.lei@redhat.com> In-Reply-To: <20250430043529.1950194-1-ming.lei@redhat.com> References: <20250430043529.1950194-1-ming.lei@redhat.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Both adding/deleting disk code are reader of `nr_hw_queues`, so we can't allow them in-progress when updating nr_hw_queues, kernel panic and kasan has been reported in [1]. Prevent adding/deleting disk during updating nr_hw_queues by adding rw_semaphore to tagset, write lock is grabbed in blk_mq_update_nr_hw_queues(), and read lock is acquired when adding/deleting disk. Also mark GFP_NOIO allocation scope for adding/deleting disk because blk_mq_update_nr_hw_queues() is part of some driver's error handler. This way avoids lot of trouble. Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Nilay Shroff Suggested-by: Nilay Shroff Reported-by: Nilay Shroff Closes: https://lore.kernel.org/linux-block/a5896cdb-a59a-4a37-9f99-20522f5d2987@linux.ibm.com/ Signed-off-by: Ming Lei --- block/blk-mq.c | 4 ++ block/genhd.c | 104 ++++++++++++++++++++++++++++------------- include/linux/blk-mq.h | 3 ++ 3 files changed, 78 insertions(+), 33 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 29cfc7ce2e0a..3706c0dde2fc 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4802,6 +4802,8 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) goto out_free_srcu; } + init_rwsem(&set->update_nr_hwq_lock); + ret = -ENOMEM; set->tags = kcalloc_node(set->nr_hw_queues, sizeof(struct blk_mq_tags *), GFP_KERNEL, @@ -5097,9 +5099,11 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) { + down_write(&set->update_nr_hwq_lock); mutex_lock(&set->tag_list_lock); __blk_mq_update_nr_hw_queues(set, nr_hw_queues); mutex_unlock(&set->tag_list_lock); + up_write(&set->update_nr_hwq_lock); } EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues); diff --git a/block/genhd.c b/block/genhd.c index c2bd86cd09de..340fb4555963 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -389,19 +389,9 @@ int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode) return ret; } -/** - * add_disk_fwnode - add disk information to kernel list with fwnode - * @parent: parent device for the disk - * @disk: per-device partitioning information - * @groups: Additional per-device sysfs groups - * @fwnode: attached disk fwnode - * - * This function registers the partitioning information in @disk - * with the kernel. Also attach a fwnode to the disk device. - */ -int __must_check add_disk_fwnode(struct device *parent, struct gendisk *disk, - const struct attribute_group **groups, - struct fwnode_handle *fwnode) +static int __add_disk(struct device *parent, struct gendisk *disk, + const struct attribute_group **groups, + struct fwnode_handle *fwnode) { struct device *ddev = disk_to_dev(disk); @@ -572,6 +562,37 @@ int __must_check add_disk_fwnode(struct device *parent, struct gendisk *disk, } return ret; } + +/** + * add_disk_fwnode - add disk information to kernel list with fwnode + * @parent: parent device for the disk + * @disk: per-device partitioning information + * @groups: Additional per-device sysfs groups + * @fwnode: attached disk fwnode + * + * This function registers the partitioning information in @disk + * with the kernel. Also attach a fwnode to the disk device. + */ +int __must_check add_disk_fwnode(struct device *parent, struct gendisk *disk, + const struct attribute_group **groups, + struct fwnode_handle *fwnode) +{ + struct blk_mq_tag_set *set; + unsigned int memflags; + int ret; + + if (!queue_is_mq(disk->queue)) + return __add_disk(parent, disk, groups, fwnode); + + set = disk->queue->tag_set; + memflags = memalloc_noio_save(); + down_read(&set->update_nr_hwq_lock); + ret = __add_disk(parent, disk, groups, fwnode); + up_read(&set->update_nr_hwq_lock); + memalloc_noio_restore(memflags); + + return ret; +} EXPORT_SYMBOL_GPL(add_disk_fwnode); /** @@ -652,26 +673,7 @@ void blk_mark_disk_dead(struct gendisk *disk) } EXPORT_SYMBOL_GPL(blk_mark_disk_dead); -/** - * del_gendisk - remove the gendisk - * @disk: the struct gendisk to remove - * - * Removes the gendisk and all its associated resources. This deletes the - * partitions associated with the gendisk, and unregisters the associated - * request_queue. - * - * This is the counter to the respective __device_add_disk() call. - * - * The final removal of the struct gendisk happens when its refcount reaches 0 - * with put_disk(), which should be called after del_gendisk(), if - * __device_add_disk() was used. - * - * Drivers exist which depend on the release of the gendisk to be synchronous, - * it should not be deferred. - * - * Context: can sleep - */ -void del_gendisk(struct gendisk *disk) +static void __del_gendisk(struct gendisk *disk) { struct request_queue *q = disk->queue; struct block_device *part; @@ -764,6 +766,42 @@ void del_gendisk(struct gendisk *disk) if (start_drain) blk_unfreeze_release_lock(q); } + +/** + * del_gendisk - remove the gendisk + * @disk: the struct gendisk to remove + * + * Removes the gendisk and all its associated resources. This deletes the + * partitions associated with the gendisk, and unregisters the associated + * request_queue. + * + * This is the counter to the respective __device_add_disk() call. + * + * The final removal of the struct gendisk happens when its refcount reaches 0 + * with put_disk(), which should be called after del_gendisk(), if + * __device_add_disk() was used. + * + * Drivers exist which depend on the release of the gendisk to be synchronous, + * it should not be deferred. + * + * Context: can sleep + */ +void del_gendisk(struct gendisk *disk) +{ + struct blk_mq_tag_set *set; + unsigned int memflags; + + if (!queue_is_mq(disk->queue)) { + __del_gendisk(disk); + } else { + set = disk->queue->tag_set; + memflags = memalloc_noio_save(); + down_read(&set->update_nr_hwq_lock); + __del_gendisk(disk); + up_read(&set->update_nr_hwq_lock); + memalloc_noio_restore(memflags); + } +} EXPORT_SYMBOL(del_gendisk); /** diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 8eb9b3310167..ef84d53095a6 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -9,6 +9,7 @@ #include #include #include +#include struct blk_mq_tags; struct blk_flush_queue; @@ -527,6 +528,8 @@ struct blk_mq_tag_set { struct mutex tag_list_lock; struct list_head tag_list; struct srcu_struct *srcu; + + struct rw_semaphore update_nr_hwq_lock; }; /** -- 2.47.0