linux-kernel - Re: [PATCH-v2 2/9] target/pr: Use atomic bitop for se_dev_entry->pr

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1432592737.722.19.camel@haakon3.risingtidesystems.com>
Date:	Mon, 25 May 2015 15:25:37 -0700
From:	"Nicholas A. Bellinger" <nab@...ux-iscsi.org>
To:	Christoph Hellwig <hch@....de>
Cc:	"Nicholas A. Bellinger" <nab@...erainc.com>,
	target-devel <target-devel@...r.kernel.org>,
	linux-scsi <linux-scsi@...r.kernel.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Hannes Reinecke <hare@...e.de>,
	Sagi Grimberg <sagig@...lanox.com>,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Subject: Re: [PATCH-v2 2/9] target/pr: Use atomic bitop for
 se_dev_entry->pr_reg reservation check

On Fri, 2015-05-22 at 13:34 +0200, Christoph Hellwig wrote:
> On Fri, May 22, 2015 at 02:05:57AM -0700, Nicholas A. Bellinger wrote:
> > On Fri, 2015-05-22 at 10:26 +0200, Christoph Hellwig wrote:
> > > On Fri, May 22, 2015 at 06:11:04AM +0000, Nicholas A. Bellinger wrote:
> > > > +	clear_bit(1, &orig->pr_reg);
> > > 
> > > Can you call it ->flags and give the bit a meaningful name?
> > 
> > The bit is signaling if se_dev_entry has a PR registration active.
> > 
> > I don't see how ->flags is a more meaningful name without other bits
> > defined.
> 
> It's pretty normal style: define a flags variable for any sort of
> bitops state that might show up, and then give the actual bits a meaningful
> name.  There's almost no users of using a magic numberic value with
> atomic bitops.
> 
> Besides being the usual and thus easier to read style it's also good
> future proofing.

Fair enough.  Changing this to ->deve_flags

> 
> > > It would be good to just sort out the registered and co variables
> > > here before the RCU changes, as in:
> > > 
> > > http://git.infradead.org/users/hch/scsi.git/commitdiff/6372d9f62c83acb30d051387c40deb4dbdcaa376
> > 
> > Why not just keep this patch squashed into the relevant commit in the
> > context of the larger RCU conversion..?
> 
> Because the logic in and aroudn core_scsi3_pr_seq_non_holder right
> now is rather confusing.  So before doing changes to it it's better
> to clean it up first, document that cleanup in a standalon patch
> and then apply the logic change on top.
> --

I'll keep it in a standalone patch, but having it precede the RCU
changes when it doesn't actually involve RCU is confusing.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/