linux-kernel - Re: [PATCH v2 09/14] block: Add an explicit bio flag for bios that own their bvec

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: <20120524213158.GB22664@google.com>
Date:	Thu, 24 May 2012 14:31:58 -0700
From:	Kent Overstreet <koverstreet@...gle.com>
To:	Boaz Harrosh <bharrosh@...asas.com>
Cc:	linux-kernel@...r.kernel.org, linux-bcache@...r.kernel.org,
	dm-devel@...hat.com, linux-fsdevel@...r.kernel.org, tj@...nel.org,
	axboe@...nel.dk, agk@...hat.com, neilb@...e.de,
	drbd-dev@...ts.linbit.com, vgoyal@...hat.com, mpatocka@...hat.com,
	sage@...dream.net, yehuda@...newdream.net
Subject: Re: [PATCH v2 09/14] block: Add an explicit bio flag for bios that
 own their bvec

On Thu, May 24, 2012 at 07:57:34PM +0300, Boaz Harrosh wrote:
> How do you insure that the original bio which owns the
> bvec is not freed before the split-out bio.
> 
> Perhaps calling code needs to make sure by taking an extra
> ref on the original bio, or something. If so a big fat comment
> at bio_split is do.

Yeah, just added that.

> 
> And I understand you did not like my suggestion of negating
> the meaning of the flag, so the default is zero?
> Please say why?

I liked it at first, but I think I prefer having the flag be set
if bio_free() must take some action; i.e. you set the flag when you
allocate bi_io_vec. Also, I think bio_alloc_bioset() getting
reimplemented is less likely than people open coding bio splitting or
something that shares bi_io_vec in the future, so it's slightlry less
likely to be used wrong this way.
--
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/