From: Bart Van Assche <Bart.VanAssche@sandisk.com>
To: "James.Bottomley@HansenPartnership.com"
<James.Bottomley@HansenPartnership.com>,
"bblock@linux.vnet.ibm.com" <bblock@linux.vnet.ibm.com>
Cc: "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
"maxg@mellanox.com" <maxg@mellanox.com>,
"israelr@mellanox.com" <israelr@mellanox.com>,
"hare@suse.de" <hare@suse.de>,
"martin.petersen@oracle.com" <martin.petersen@oracle.com>
Subject: Re: [PATCH v3 3/4] sd: Make synchronize cache upon shutdown asynchronous
Date: Thu, 20 Apr 2017 22:52:22 +0000 [thread overview]
Message-ID: <1492728740.2642.14.camel@sandisk.com> (raw)
In-Reply-To: <1492726397.21601.16.camel@HansenPartnership.com>
On Thu, 2017-04-20 at 15:13 -0700, James Bottomley wrote:
> How is that possible? Once the device goes into the CANCEL state, it
> no longer can be found by starget_for_each_device() because
> scsi_device_get() returns NULL ...
scsi_target_block() is not serialized against __scsi_remove_device(). I think
the following sequence of events can cause a queue to be stopped for a device
in the CANCEL state:
(a) scsi_target_block() triggers a call to scsi_get_device().
(b) __scsi_remove_device() is called from the context of another thread.
(c) __scsi_remove_device() changes the device state into SDEV_CANCEL.
(d) scsi_internal_device_block() calls blk_mq_stop_hw_queue().
Bart.
next prev parent reply other threads:[~2017-04-20 22:52 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-17 17:34 [PATCH v3 0/4] Avoid that __scsi_remove_device() hangs Bart Van Assche
2017-04-17 17:34 ` [PATCH v3 1/4] Introduce scsi_start_queue() Bart Van Assche
2017-04-17 17:34 ` [PATCH v3 2/4] Introduce scsi_execute_async() Bart Van Assche
2017-04-17 17:34 ` [PATCH v3 3/4] sd: Make synchronize cache upon shutdown asynchronous Bart Van Assche
2017-04-18 14:44 ` Benjamin Block
2017-04-18 15:34 ` Bart Van Assche
2017-04-18 15:56 ` James Bottomley
2017-04-18 16:06 ` Bart Van Assche
2017-04-18 23:47 ` Bart Van Assche
2017-04-18 23:56 ` James Bottomley
2017-04-19 0:02 ` Bart Van Assche
2017-04-19 0:05 ` James Bottomley
2017-04-19 18:42 ` Bart Van Assche
2017-04-20 21:59 ` Bart Van Assche
2017-04-20 22:13 ` James Bottomley
2017-04-20 22:27 ` Bart Van Assche
2017-04-20 22:52 ` Bart Van Assche [this message]
2017-04-23 17:28 ` James Bottomley
2017-04-24 21:46 ` Bart Van Assche
2017-04-26 18:53 ` Bart Van Assche
2017-04-28 18:45 ` James Bottomley
2017-04-24 7:14 ` [lkp-robot] [sd] ab1218235c: INFO:possible_recursive_locking_detected kernel test robot
2017-04-17 17:34 ` [PATCH v3 4/4] Avoid that __scsi_remove_device() hangs Bart Van Assche
2017-04-18 11:58 ` [PATCH v3 0/4] " Israel Rukshin
2017-04-18 15:40 ` Bart Van Assche
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=1492728740.2642.14.camel@sandisk.com \
--to=bart.vanassche@sandisk.com \
--cc=James.Bottomley@HansenPartnership.com \
--cc=bblock@linux.vnet.ibm.com \
--cc=hare@suse.de \
--cc=israelr@mellanox.com \
--cc=linux-scsi@vger.kernel.org \
--cc=martin.petersen@oracle.com \
--cc=maxg@mellanox.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox