Linux-Block Archive on lore.kernel.org
 help / color / Atom feed
From: Hannes Reinecke <hare@suse.de>
To: Bart Van Assche <bvanassche@acm.org>,
	"Martin K . Petersen" <martin.petersen@oracle.com>
Cc: "James E . J . Bottomley" <jejb@linux.vnet.ibm.com>,
	Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@lst.de>,
	Ming Lei <ming.lei@redhat.com>,
	linux-scsi@vger.kernel.org, linux-block@vger.kernel.org,
	Alan Stern <stern@rowland.harvard.edu>,
	Can Guo <cang@codeaurora.org>,
	Stanley Chu <stanley.chu@mediatek.com>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	Martin Kepplinger <martin.kepplinger@puri.sm>
Subject: Re: [PATCH v5 8/8] block: Do not accept any requests while suspended
Date: Wed, 9 Dec 2020 08:36:26 +0100
Message-ID: <b257a342-0066-60a6-0bd1-801f502b6d96@suse.de> (raw)
In-Reply-To: <20201209052951.16136-9-bvanassche@acm.org>

On 12/9/20 6:29 AM, Bart Van Assche wrote:
> From: Alan Stern <stern@rowland.harvard.edu>
> 
> blk_queue_enter() accepts BLK_MQ_REQ_PM requests independent of the runtime
> power management state. Now that SCSI domain validation no longer depends
> on this behavior, modify the behavior of blk_queue_enter() as follows:
> - Do not accept any requests while suspended.
> - Only process power management requests while suspending or resuming.
> 
> Submitting BLK_MQ_REQ_PM requests to a device that is runtime suspended
> causes runtime-suspended devices not to resume as they should. The request
> which should cause a runtime resume instead gets issued directly, without
> resuming the device first. Of course the device can't handle it properly,
> the I/O fails, and the device remains suspended.
> 
> The problem is fixed by checking that the queue's runtime-PM status
> isn't RPM_SUSPENDED before allowing a request to be issued, and
> queuing a runtime-resume request if it is.  In particular, the inline
> blk_pm_request_resume() routine is renamed blk_pm_resume_queue() and
> the code is unified by merging the surrounding checks into the
> routine.  If the queue isn't set up for runtime PM, or there currently
> is no restriction on allowed requests, the request is allowed.
> Likewise if the BLK_MQ_REQ_PM flag is set and the status isn't
> RPM_SUSPENDED.  Otherwise a runtime resume is queued and the request
> is blocked until conditions are more suitable.
> 
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Hannes Reinecke <hare@suse.de>
> Cc: Can Guo <cang@codeaurora.org>
> Cc: Stanley Chu <stanley.chu@mediatek.com>
> Cc: Ming Lei <ming.lei@redhat.com>
> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Reported-and-tested-by: Martin Kepplinger <martin.kepplinger@puri.sm>
> Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> [ bvanassche: modified commit message and removed Cc: stable because without
>    the previous patches from this series this patch would break parallel SCSI
>    domain validation + introduced queue_rpm_status() ]
> ---
>   block/blk-core.c       |  7 ++++---
>   block/blk-pm.h         | 14 +++++++++-----
>   include/linux/blkdev.h | 12 ++++++++++++
>   3 files changed, 25 insertions(+), 8 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer

  parent reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-09  5:29 [PATCH v5 0/8] Rework runtime suspend and SPI domain validation Bart Van Assche
2020-12-09  5:29 ` [PATCH v5 1/8] block: Fix a race in the runtime power management code Bart Van Assche
2020-12-09  5:29 ` [PATCH v5 2/8] block: Introduce BLK_MQ_REQ_PM Bart Van Assche
2020-12-09  6:06   ` Can Guo
2020-12-09  5:29 ` [PATCH v5 3/8] ide: Do not set the RQF_PREEMPT flag for sense requests Bart Van Assche
2020-12-09  5:29 ` [PATCH v5 4/8] ide: Mark power management requests with RQF_PM instead of RQF_PREEMPT Bart Van Assche
2020-12-09  5:29 ` [PATCH v5 5/8] scsi_transport_spi: Set RQF_PM for domain validation commands Bart Van Assche
2020-12-09  7:34   ` Hannes Reinecke
2020-12-09  5:29 ` [PATCH v5 6/8] scsi: Only process PM requests if rpm_status != RPM_ACTIVE Bart Van Assche
2020-12-09  6:06   ` Can Guo
2020-12-09  5:29 ` [PATCH v5 7/8] block: Remove RQF_PREEMPT and BLK_MQ_REQ_PREEMPT Bart Van Assche
2020-12-09  6:05   ` Can Guo
2020-12-09  5:29 ` [PATCH v5 8/8] block: Do not accept any requests while suspended Bart Van Assche
2020-12-09  6:04   ` Can Guo
2020-12-09  7:36   ` Hannes Reinecke [this message]
2020-12-09 16:44 ` [PATCH v5 0/8] Rework runtime suspend and SPI domain validation Martin K. Petersen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=b257a342-0066-60a6-0bd1-801f502b6d96@suse.de \
    --to=hare@suse.de \
    --cc=axboe@kernel.dk \
    --cc=bvanassche@acm.org \
    --cc=cang@codeaurora.org \
    --cc=hch@lst.de \
    --cc=jejb@linux.vnet.ibm.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=martin.kepplinger@puri.sm \
    --cc=martin.petersen@oracle.com \
    --cc=ming.lei@redhat.com \
    --cc=rafael.j.wysocki@intel.com \
    --cc=stanley.chu@mediatek.com \
    --cc=stern@rowland.harvard.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Block Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-block/0 linux-block/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-block linux-block/ https://lore.kernel.org/linux-block \
		linux-block@vger.kernel.org
	public-inbox-index linux-block

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-block


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git