From: Christoph Hellwig <hch@infradead.org>
To: James Bottomley <jejb@linux.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>,
Merlijn Wajer <merlijn@archive.org>,
merlijn@wizzup.org, linux-scsi@vger.kernel.org,
Jens Axboe <axboe@kernel.dk>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Arnd Bergmann <arnd@arndb.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] scsi: sr: get rid of sr global mutex
Date: Tue, 18 Feb 2020 09:23:47 -0800 [thread overview]
Message-ID: <20200218172347.GA3020@infradead.org> (raw)
In-Reply-To: <1582046428.16681.7.camel@linux.ibm.com>
On Tue, Feb 18, 2020 at 09:20:28AM -0800, James Bottomley wrote:
> > > Replace the global mutex with per-sr-device mutex.
> >
> > Do we actually need the lock at all? What is protected by it?
>
> We do at least for cdrom_open. It modifies the cdi structure with no
> other protection and concurrent modification would at least screw up
> the use counter which is not atomic. Same reasoning for cdrom_release.
Wouldn't the right fix to add locking to cdrom_open/release instead of
having an undocumented requirement for the callers?
next prev parent reply other threads:[~2020-02-18 17:23 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-18 14:39 Merlijn Wajer
2020-02-18 17:12 ` Christoph Hellwig
2020-02-18 17:20 ` James Bottomley
2020-02-18 17:23 ` Christoph Hellwig [this message]
2020-02-18 17:28 ` James Bottomley
2020-02-18 17:31 ` Christoph Hellwig
2020-02-18 19:21 ` Merlijn B.W. Wajer
2020-02-18 19:46 ` Arnd Bergmann
2020-02-24 21:20 ` Merlijn B.W. Wajer
[not found] <9d50ecd4-9fd1-6865-5509-a5ef119828df () archive ! org>
2020-03-06 22:43 ` Simon Arlott
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=20200218172347.GA3020@infradead.org \
--to=hch@infradead.org \
--cc=arnd@arndb.de \
--cc=axboe@kernel.dk \
--cc=jejb@linux.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=martin.petersen@oracle.com \
--cc=merlijn@archive.org \
--cc=merlijn@wizzup.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
Powered by JetHome