From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Jens Axboe <jens.axboe@oracle.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>,
LKML <linux-kernel@vger.kernel.org>,
martin.petersen@oracle.com
Subject: Re: [PATCH] block: fix memory leak in bio_clone()
Date: Mon, 09 Mar 2009 12:10:27 -0400 [thread overview]
Message-ID: <yq1prgqy8wc.fsf@sermon.lab.mkp.net> (raw)
In-Reply-To: <20090309092407.GI11787@kernel.dk> (Jens Axboe's message of "Mon\, 9 Mar 2009 10\:24\:07 +0100")
>>>>> "Jens" == Jens Axboe <jens.axboe@oracle.com> writes:
Jens> So the leak will not occur, but it does mean that it isn't
Jens> honoring the gfp_mask passed in to bio_clone(), which is the first
Jens> bug.
bio_integrity_clone() had no mask because all callers of it used
GFP_NOIO explicitly.
But as you now recall there is a patch queued that adds the mask :)
Jens> The second bug is that it should be using its own bioset, as it is
Jens> illegal to do multiple __GFP_WAIT allocations on a single mempool
Jens> and always expect progress.
So how do you propose I go about this?
The original intent was to contain all the integrity blah inside the
bio_set to make it completely transparent to the caller. That's why the
bip mempool is hanging off of the bio_set. But obviously two bvecs are
needed per bio, one to describe data and to describe the integrity
buffer.
Having two bvec mempools per bio_set seems icky. I guess what you are
suggesting is that we could have a dedicated bio_integrity_set akin to
the bio_split_pool. That removes the caller's option of passing a
dedicated bio_set to the clone command, though. Will that have forward
progress implications for stacking drivers?
--
Martin K. Petersen Oracle Linux Engineering
next prev parent reply other threads:[~2009-03-09 16:10 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-09 9:13 Li Zefan
2009-03-09 9:21 ` Li Zefan
2009-03-09 9:24 ` Jens Axboe
2009-03-09 9:34 ` Li Zefan
2009-03-09 9:38 ` Jens Axboe
2009-03-09 9:51 ` Li Zefan
2009-03-09 9:54 ` Jens Axboe
2009-03-09 16:10 ` Martin K. Petersen [this message]
2009-03-09 19:21 ` Jens Axboe
2009-03-10 3:42 ` Martin K. Petersen
2009-03-10 7:29 ` Jens Axboe
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