From: Christoph Hellwig <hch@lst.de>
To: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Ewan Milne <emilne@redhat.com>,
Bart van Assche <bart.vanassche@sandisk.com>,
James Bottomley <james.bottomley@hansenpartnership.com>,
linux-scsi@vger.kernel.org, Hannes Reinecke <hare@suse.com>
Subject: Re: [PATCH][RESEND] scsi_sysfs: add 'is_bin_visible' callback
Date: Wed, 2 Mar 2016 10:19:16 +0100 [thread overview]
Message-ID: <20160302091916.GE1308@lst.de> (raw)
In-Reply-To: <56D6973A.4070901@suse.de>
On Wed, Mar 02, 2016 at 03:33:14PM +0800, Hannes Reinecke wrote:
> >> + rcu_read_lock();
> >> + if (attr == &dev_attr_vpd_pg80 &&
> >> + !rcu_dereference(sdev->vpd_pg80)) {
> >> + rcu_read_unlock();
> >> + return 0;
> >> + }
> >> + if (attr == &dev_attr_vpd_pg83 &&
> >> + !rcu_dereference(sdev->vpd_pg83)) {
> >> + rcu_read_unlock();
> >> + return 0;
> >> + }
> >> + rcu_read_unlock();
> >
> > We are only checking the pointers for being non-zero. No need for the
> > rcu_read_lock() or rcu_dereference() here.
> >
> Better to be same than sorry; some overly clever code analysis tool
> might trip over it otherwise.
It shouldn't. There is no dereference going on here.
>
> > Otherwise this looks fine to me.
>
> Reviewed-by: ?
Only without the cargo culted rcu magic.
next prev parent reply other threads:[~2016-03-02 9:19 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-01 4:52 [PATCH][RESEND] scsi_sysfs: add 'is_bin_visible' callback Hannes Reinecke
2016-03-01 6:45 ` Seymour, Shane M
2016-03-01 9:08 ` Johannes Thumshirn
2016-03-01 13:04 ` Christoph Hellwig
2016-03-02 7:33 ` Hannes Reinecke
2016-03-02 9:19 ` Christoph Hellwig [this message]
2016-03-02 9:34 ` Hannes Reinecke
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