From: Tejun Heo <htejun@gmail.com>
To: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Jens Axboe <axboe@suse.de>,
SCSI Mailing List <linux-scsi@vger.kernel.org>,
Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH scsi-misc-2.6 07/08] scsi: remove bogus {get|put}_device() calls
Date: Wed, 23 Mar 2005 18:13:26 +0900 [thread overview]
Message-ID: <42413336.2010004@gmail.com> (raw)
In-Reply-To: <1111551355.5520.100.camel@mulgrave>
Hi,
James Bottomley wrote:
> On Wed, 2005-03-23 at 11:14 +0900, Tejun Heo wrote:
>
>> So, basically, SCSI high-level object (scsi_disk) and
>> mid-level object (scsi_device) are reference counted by users,
>> not the requests they submit. Reference count cannot go zero
>> with active users and users cannot access the object once the
>> reference count reaches zero.
>
>
> Actually, no. Unfortunately we still have some fire and forget APIs, so
> the contention that we always have an open refcounted descriptor isn't
> always true.
Yeap, you're right. So, what we have is
* All high-level users have open access to the scsi high-level
object on issueing requests, but may close it before its requests
complete.
* All mid-layer users do get_device() before submitting requests,
but may put_device() before its requests complete.
Thanks for pointing that out. :-)
--
tejun
next prev parent reply other threads:[~2005-03-23 9:13 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-23 2:14 [PATCH scsi-misc-2.6 00/08] scsi: small fixes & cleanups Tejun Heo
2005-03-23 2:14 ` [PATCH scsi-misc-2.6 01/08] scsi: remove unused bounce-buffer release path Tejun Heo
2005-03-23 4:07 ` James Bottomley
2005-03-23 6:08 ` Tejun Heo
2005-03-23 15:27 ` Jens Axboe
2005-03-23 2:14 ` [PATCH scsi-misc-2.6 02/08] scsi: don't use blk_insert_request() for requeueing Tejun Heo
2005-03-23 2:14 ` [PATCH scsi-misc-2.6 03/08] scsi: remove unused scsi_cmnd->internal_timeout field Tejun Heo
2005-03-23 2:14 ` [PATCH scsi-misc-2.6 04/08] scsi: remove meaningless volatile qualifiers from structure definitions Tejun Heo
2005-03-23 4:15 ` James Bottomley
2005-03-23 4:22 ` Jeff Garzik
2005-03-23 5:28 ` Tejun Heo
2005-03-23 15:16 ` James Bottomley
2005-03-23 2:14 ` [PATCH scsi-misc-2.6 05/08] scsi: remove a timer race from scsi_queue_insert() and cleanup timer Tejun Heo
2005-03-23 2:14 ` [PATCH scsi-misc-2.6 06/08] scsi: remove meaningless scsi_cmnd->serial_number_at_timeout field Tejun Heo
2005-03-23 2:14 ` [PATCH scsi-misc-2.6 07/08] scsi: remove bogus {get|put}_device() calls Tejun Heo
2005-03-23 4:15 ` James Bottomley
2005-03-23 9:13 ` Tejun Heo [this message]
2005-03-29 17:02 ` Patrick Mansfield
2005-03-23 2:14 ` [PATCH scsi-misc-2.6 08/08] scsi: fix hot unplug sequence Tejun Heo
2005-03-23 4:08 ` James Bottomley
2005-03-23 4:50 ` Tejun Heo
2005-03-23 7:19 ` Jens Axboe
2005-03-23 15:20 ` James Bottomley
2005-03-23 15:25 ` Jens Axboe
2005-03-25 0:45 ` James Bottomley
2005-03-25 3:15 ` Tejun Heo
2005-03-25 5:02 ` James Bottomley
2005-03-25 5:38 ` Tejun Heo
2005-03-25 19:19 ` James Bottomley
2005-03-25 21:43 ` Tejun Heo
2005-03-25 22:49 ` James Bottomley
2005-03-26 7:27 ` Kai Makisara
2005-03-26 14:48 ` James Bottomley
2005-03-23 15:12 ` James Bottomley
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=42413336.2010004@gmail.com \
--to=htejun@gmail.com \
--cc=James.Bottomley@SteelEye.com \
--cc=axboe@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
/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