From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.189 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792481976; b=Cf++yTZaaH+KwEfL/bHdDb8/xMwTsOlywwXYsXnqvNB5VcMzoizn3re/qmwQNCrMbK5S 1KzhHqWCENUitCgFiUmFbNyEGEU6Qf5urhFO6SomTl8FIxi+1smYZTjPnNsTlqemdERfs xz7b+5+I10s/EjabqrhfbLKte+8+9Yp9f/kcXu4RY3UXmJLs/urdFUZNkuFg7WnxKTDpi bAKkbL6jmuJe81HP9y23N6KXFYu4O3QRjKQrjccE33wy938VuQ2P91p6CM0TR5ha6BazU Y2YQbtKXWFV5UDwRAjGro30XNCju+/CzsNEXX+hqtC/tshnZSiEzcPxAau7UlVfqi3A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792481976; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:Content-Language:From:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=1zGO+HS6XqWqoMXi7NdxrkJcFUMvHUc+0QyWCt8YQbs=; b=DviVfCEeB8nKmKgs/C+k6mSIyLnVX/ZsLaYLwugig7K9kTygnMzJSeh3wT+ma9Ilr5Ee Wm1kvPr48pBYgytYaG7vZtG+IThcqaSuFkfXWEOL6nN2rvnIqb2flFT5dAVbXj50T/1XF Xb1mp6lWWLJQ072gbNa/IUZp7kPvYonFClMATDdKn2gdQieuz0gZ46eS3gItx607lFLol Xzs6i58469zd+RrCh0yoYC975WUG79LyfrX+3WANXu5RCknjEGd+si5aYHvmxQByQq3nr VbaRszxm1KA67jglikaqOfbUs+VFuv01KIuYdQ8Grl1J8Xr08+vUn60bK9RU6X8NDBA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=YfgJpw7T; arc=none smtp.remote-ip=91.218.175.189 Received: from mta0.migadu.com (out-189.mta0.migadu.com [91.218.175.189]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 422E9606A32E for ; Tue, 20 Oct 2026 07:39:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 422E9606A32E Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=YfgJpw7T X-Envelope-To: linux-scsi@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=20TkE5EUd8YHt+v29oUMkAh6L5UeQPp7EcPr9ORP67M=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1792481973; v=1; x=1793086773; b=YfgJpw7ThpO+VG30/4JQmJEBXHf5ozauhPylRtwSHkWAI0sKHbmPEWNEnuIqbYdW+DKIEoc3 jU13r6TAIDVi1RCWd9L/14RFAWVn2p6Oizff1Ac01TaBaePumxhH+KY899TTyLsMamD9k6Ns+6A dmJzHeyGUnkCZYTFtGAis2xU= X-Envelope-To: linux-scsi@vger.kernel.org Received: by mta12.migadu.com with ESMTPS id 0b179a5dfc27a0f9; Tue, 20 Oct 2026 07:39:33 +0000 X-Mizu-Trace-ID: 0b179a5dfc27a0f9 X-Migadu-Flow: FLOW_OUT Message-ID: <557f3415-ea6c-4fba-844e-6d59f71f2ca0@linux.dev> Date: Tue, 20 Oct 2026 08:39:31 +0100 X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] scsi: sd: Mark the disk dead if runtime resume fails in sd_remove() To: Bart Van Assche , "Martin K . Petersen" Cc: linux-scsi@vger.kernel.org, Christoph Hellwig , Lianqin Hu , stable@vger.kernel.org References: <2c0c76d70f0fe197932836b9bcf8496095135d1b.1792446921.git.bvanassche@acm.org> Content-Language: en-US From: John Garry In-Reply-To: <2c0c76d70f0fe197932836b9bcf8496095135d1b.1792446921.git.bvanassche@acm.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/19/26 22:55, Bart Van Assche wrote: > If a SCSI disk is unplugged while runtime suspended, its request queue > is still in the pm-only state when sd_remove() is called. The runtime > resume attempted by scsi_autopm_get_device() fails because the parent > device, e.g. a USB device in the USB_STATE_NOTATTACHED state, cannot be > resumed. Hence, sdev_runtime_resume() is not called and the pm-only > state is not cleared. Next, del_gendisk() calls > blk_report_disk_dead(disk, false), which calls sync_filesystem(). Any > bio submitted by the filesystem waits forever in __bio_queue_enter() > because the queue will never leave the pm-only state and because > GD_DEAD has not yet been set: > > __bio_queue_enter+0xb8/0x174 > blk_mq_submit_bio+0x640/0x7e4 > [ ... ] > exfat_sync_fs+0xa4/0xe0 > sync_filesystem+0xa8/0xdc > fs_bdev_mark_dead+0x30/0x88 > bdev_mark_dead+0x54/0xc4 > blk_report_disk_dead+0x8c/0xd4 > del_gendisk+0xa0/0x2f8 > sd_remove+0x30/0x60 > [ ... ] > scsi_remove_host+0x88/0x18c > usb_stor_disconnect+0x68/0xf4 > > Fix this hang by calling blk_mark_disk_dead() if runtime resume fails. > This sets GD_DEAD, tells the filesystem that the disk has been removed > without attempting to sync it, and wakes up any bios that are waiting > in __bio_queue_enter(). Syncing the filesystem is not possible anyway > if runtime resume failed, so no data is lost that could otherwise have > been written. If runtime resume succeeds, behavior is not changed. > > Please note that this patch converts temporary runtime resume failures > into permanent failures. Before this patch, if runtime resume fails > temporarily, a filesytem sync would be postponed until a later resume > succeeds. > > Cc: Christoph Hellwig > Tested-by: Lianqin Hu > Reported-by: Lianqin Hu > Closes: https://lore.kernel.org/all/TYUPR06MB6217DD31B1B3CD09E431CC12D2922@TYUPR06MB6217.apcprd06.prod.outlook.com/ > Fixes: 6f8191fdf41d ("block: simplify disk shutdown") > Cc: stable@vger.kernel.org > Signed-off-by: Bart Van Assche FWIW: Reviewed-by: John Garry > --- > drivers/scsi/sd.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c > index b0d2542fd317..dc45df819c42 100644 > --- a/drivers/scsi/sd.c > +++ b/drivers/scsi/sd.c > @@ -4268,7 +4268,15 @@ static void sd_remove(struct scsi_device *sdp) > struct device *dev = &sdp->sdev_gendev; > struct scsi_disk *sdkp = dev_get_drvdata(dev); > > - scsi_autopm_get_device(sdkp->device); > + /* > + * If runtime resume fails, e.g. because the device was unplugged > + * while runtime suspended, the request queue stays in the pm-only > + * state and any I/O submitted by del_gendisk(), e.g. from > + * sync_filesystem(), would wait forever in __bio_queue_enter(). > + * Prevent this by marking the disk dead. > + */ > + if (scsi_autopm_get_device(sdkp->device) < 0) Does this scsi_autopm_get_device() match with a "put", or does it even matter since the device is going away? > + blk_mark_disk_dead(sdkp->disk); > > device_del(&sdkp->disk_dev); > del_gendisk(sdkp->disk);