linux-kernel - Re: [PATCH] block: Force sector and nr_sects to device alignment and granularity.

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 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]

Date:	Tue, 11 Mar 2014 09:02:58 -0700
From:	Frank Mayhar <fmayhar@...gle.com>
To:	Jeff Moyer <jmoyer@...hat.com>
Cc:	Jens Axboe <axboe@...nel.dk>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] block:  Force sector and nr_sects to device alignment
 and granularity.

On Tue, 2014-03-11 at 11:15 -0400, Jeff Moyer wrote:
> Frank Mayhar <fmayhar@...gle.com> writes:
> 
> > block:  Force sector and nr_sects to device alignment and granularity.
> >
> > In blkdev_issue_discard(), rather than sending an improperly-
> > aligned discard to the device (where it may get an error),
> > adjust the start and length to the block device alignment and
> > granularity.  Don't fail if this leaves nothing to discard.
> >
> > Without this change, certain flash drivers can report invalid
> > trim parameters (and will fail the command).  Per tytso, "given
> > that discards are advisory, any part of the storage stack is
> > free to drop discard requests silently."
> 
> And how do you get here with misaligned discards?

I don't understand the question.

The case that we were seeing was with an SSD that required TRIM on 8k
boundaries and with an 8k granularity.  Since the file system was trying
to do discards based on 4k alignment the driver complained mightily.
-- 
Frank Mayhar
310-460-4042

--
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/