From: Bart Van Assche <bvanassche@acm.org>
To: Mike Christie <michaelc@cs.wisc.edu>
Cc: Tomas Henzl <thenzl@redhat.com>,
"'linux-scsi@vger.kernel.org'" <linux-scsi@vger.kernel.org>,
Stanislaw Gruszka <sgruszka@redhat.com>
Subject: Re: [RFC] How to fix an async scan - rmmod race?
Date: Fri, 06 Apr 2012 09:24:40 +0000 [thread overview]
Message-ID: <4F7EB658.9060109@acm.org> (raw)
In-Reply-To: <4F7E0EBF.80407@cs.wisc.edu>
On 04/05/12 21:29, Mike Christie wrote:
> Tomas's bug occurs when drivers use scsi_scan_host, use the async scsi
> device scanning, and then rmmod the LLD while the scan is still in progress.
>
> I think a general problem that we might hit similar to Tomas's issue is
> when scanning from userspace then rmmoding the driver. Maybe that means
> we need a more generic fix? Or, maybe that could be handled by having
> scsi_scan() do a try_module_get before scanning.
That suggestion certainly makes sense to me. But Tomas' approach has the
advantage that it guarantees that scanning will have finished once
scsi_remove_hosts() returned and hence has less potential for triggering
race conditions than an approach based on try_module_get().
Bart.
next prev parent reply other threads:[~2012-04-06 9:24 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-05 13:58 [RFC] How to fix an async scan - rmmod race? Tomas Henzl
2012-04-05 15:57 ` Mike Christie
2012-04-05 16:05 ` Mike Christie
2012-04-05 18:00 ` Bart Van Assche
2012-04-05 21:29 ` Mike Christie
2012-04-06 9:24 ` Bart Van Assche [this message]
2012-04-06 17:22 ` Mike Christie
2012-04-06 18:37 ` Bart Van Assche
2012-04-11 21:46 ` Mike Christie
2012-04-06 9:54 ` Tomas Henzl
2012-04-06 15:20 ` James Bottomley
2012-04-06 16:15 ` Bart Van Assche
2012-04-06 16:35 ` James Bottomley
2012-04-06 17:01 ` Bart Van Assche
2012-04-06 17:15 ` James Bottomley
2012-04-06 17:59 ` Bart Van Assche
2012-04-08 17:38 ` Bart Van Assche
2012-04-11 18:17 ` Mike Christie
2012-04-11 18:30 ` Mike Christie
2012-04-11 19:47 ` Bart Van Assche
2012-04-11 22:28 ` Mike Christie
2012-04-12 10:48 ` Bart Van Assche
2012-04-06 9:39 ` Bart Van Assche
2012-04-06 10:14 ` Tomas Henzl
2012-04-06 13:13 ` Tomas Henzl
2012-04-06 14:38 ` Bart Van Assche
2012-04-06 15:32 ` Tomas Henzl
2012-04-12 12:48 ` [RFC] How to fix an async scan - rmmod race? try_module_get Tomas Henzl
2012-04-18 16:48 ` [RFC] How to fix an async scan - 'rmmod --wait' race? Tomas Henzl
2012-04-18 18:18 ` Bart Van Assche
2012-05-17 8:42 ` James Bottomley
2012-05-17 8:55 ` Bart Van Assche
2012-05-17 9:01 ` James Bottomley
2012-05-17 14:51 ` Tomas Henzl
2012-05-22 10:05 ` James Bottomley
2012-05-25 15:13 ` Tomas Henzl
2012-05-25 18:46 ` Dan Williams
2012-05-28 11:58 ` Tomas Henzl
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=4F7EB658.9060109@acm.org \
--to=bvanassche@acm.org \
--cc=linux-scsi@vger.kernel.org \
--cc=michaelc@cs.wisc.edu \
--cc=sgruszka@redhat.com \
--cc=thenzl@redhat.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.