From: Nick Piggin <npiggin@suse.de>
To: carsteno@de.ibm.com
Cc: Christian Borntraeger <borntraeger@de.ibm.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-fsdevel@vger.kernel.org,
"Eric W. Biederman" <ebiederm@xmission.com>,
Andrew Morton <akpm@linux-foundation.org>,
rob@landley.net, Jens Axboe <axboe@kernel.dk>
Subject: Re: [patch] ext2: xip check fix
Date: Thu, 6 Dec 2007 09:52:23 +0100 [thread overview]
Message-ID: <20071206085223.GA25202@wotan.suse.de> (raw)
In-Reply-To: <4757B62F.2040608@de.ibm.com>
On Thu, Dec 06, 2007 at 09:43:27AM +0100, Carsten Otte wrote:
> Nick Piggin wrote:
> >>Xip does only work, if both do match PAGE_SIZE because it
> >>does'nt support multiple calls to direct_access in the get_xip_page
> >>address space operation. Thus we check both here, actually this was
> >>changed from how it looks after your patch as a bugfix where our
> >>tester tried a 4k filesystem on a 2k blockdev.
> >>Did I miss something?
> >
> >However, the bdev block size may be changed with sb_set_blocksize. It
> >doesn't actually have to match the hardware sector size -- if this
> >does matter for XIP, then I think you need some other check here.
> Hmmmmhh. For a bdev with PAGE_SIZE hardsect size, there is no other
> valid value then PAGE_SIZE that one could set it to. Or can it indeed
> be changed to a value greater then PAGE_SIZE or smaller then hardsect
> size?
It can't be made smaller (or larger, in current kernels). But you
already get all that checking done for you -- both by checking that
the filesystem blocksize == PAGE_SIZE, and by the error checking in
sb_set_blocksize.
After my patch, we can do XIP in a hardsect size < PAGE_SIZE block
device -- this seems to be a fine thing to do at least for the
ramdisk code. Would this situation be problematic for existing drivers,
and if so, in what way?
Thanks,
Nick
next prev parent reply other threads:[~2007-12-06 8:52 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-04 4:26 [patch] rewrite rd Nick Piggin
2007-12-04 6:29 ` Andrew Morton
2007-12-04 7:01 ` Nick Piggin
2007-12-04 7:08 ` Nick Piggin
2007-12-04 7:55 ` Rob Landley
2007-12-04 9:29 ` Nick Piggin
2007-12-04 19:53 ` Rob Landley
2007-12-04 9:54 ` Christian Borntraeger
2007-12-04 10:10 ` Nick Piggin
2007-12-04 11:21 ` [patch] rd: support XIP Nick Piggin
2007-12-04 11:23 ` [patch] ext2: xip check fix Nick Piggin
2007-12-05 15:43 ` Carsten Otte
2007-12-05 23:33 ` Nick Piggin
2007-12-06 8:43 ` Carsten Otte
2007-12-06 8:52 ` Nick Piggin [this message]
2007-12-06 9:59 ` Carsten Otte
2007-12-06 10:18 ` Nick Piggin
2007-12-06 10:24 ` Carsten Otte
2007-12-06 18:11 ` Rob Landley
2007-12-07 3:22 ` Jared Hulbert
2007-12-07 4:17 ` Rob Landley
2007-12-07 4:23 ` Nick Piggin
2007-12-07 4:40 ` Jared Hulbert
2007-12-07 8:59 ` Carsten Otte
2007-12-07 9:52 ` Jared Hulbert
2007-12-04 11:26 ` [patch] rd: support XIP Andrew Morton
2007-12-04 11:35 ` Nick Piggin
2007-12-04 13:00 ` [patch] mm: fix XIP file writes Nick Piggin
2007-12-10 14:38 ` Christian Borntraeger
2007-12-12 4:03 ` Nick Piggin
2007-12-04 12:06 ` [patch] rd: support XIP Duane Griffin
2007-12-04 13:03 ` [patch] rd: support XIP (updated) Nick Piggin
2008-01-14 16:47 ` [patch] rewrite rd Matthew Wilcox
2008-01-14 17:21 ` Jens Axboe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20071206085223.GA25202@wotan.suse.de \
--to=npiggin@suse.de \
--cc=akpm@linux-foundation.org \
--cc=axboe@kernel.dk \
--cc=borntraeger@de.ibm.com \
--cc=carsteno@de.ibm.com \
--cc=ebiederm@xmission.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rob@landley.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).