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From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Boaz Harrosh <bharrosh@panasas.com>
Cc: Matthew Wilcox <matthew@wil.cx>,
	linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org,
	Tejun Heo <tj@kernel.org>
Subject: Re: Getting TRIM working
Date: Sun, 08 Mar 2009 16:32:36 -0500	[thread overview]
Message-ID: <1236547956.4861.17.camel@localhost.localdomain> (raw)
In-Reply-To: <1236547480.4861.12.camel@localhost.localdomain>

On Sun, 2009-03-08 at 16:24 -0500, James Bottomley wrote:
> The problem in the prepare is you need to set up a command with data.
> What I'm not quite clear on is why blk_rq_map_kern() on a kmalloc'd
> buffer can't be used.  You'd end up with a dual bio request (one for the
> discard, one for the data), but they should tear down correctly using
> the separate bio teardowns and pass correctly into blk_rq_map_sg() which
> was the original point.

Actually, found the reason, blk_rq_map_kern will blast the original bio
from the request.  You could fix this by chaining it back again at the
beginning.  If that works, we could just wrap it into a block API to
prevent users from having to muck with bios.

James



  reply	other threads:[~2009-03-08 21:32 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-03 19:07 Getting TRIM working Matthew Wilcox
2009-03-04  9:20 ` Boaz Harrosh
2009-03-06 19:16   ` Matthew Wilcox
2009-03-08 10:28     ` Boaz Harrosh
2009-03-08 16:54       ` Matthew Wilcox
2009-03-08 17:38         ` Boaz Harrosh
2009-03-08 21:24       ` James Bottomley
2009-03-08 21:32         ` James Bottomley [this message]
2009-03-09  8:36           ` Matthew Wilcox
2009-03-09 13:52             ` Douglas Gilbert
2009-03-09 14:03               ` INCITS Matthew Wilcox
2009-03-09 14:08               ` Getting TRIM working James Bottomley
2009-03-09 14:04             ` James Bottomley
2009-03-09 14:14               ` Matthew Wilcox
2009-03-09 15:17                 ` Matthew Wilcox

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