From: Tejun Heo <tj@kernel.org>
To: Milan Broz <mbroz@redhat.com>
Cc: Tao Ma <tm@tao.ma>,
linux-kernel@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
device-mapper development <dm-devel@redhat.com>
Subject: Re: [PATCH][RFC] dm: Do not open log and cow device read-write for read-only mappings
Date: Mon, 14 Feb 2011 15:09:40 +0100 [thread overview]
Message-ID: <20110214140940.GM18742@htj.dyndns.org> (raw)
In-Reply-To: <4D592AD1.6020500@redhat.com>
Hello,
On Mon, Feb 14, 2011 at 02:14:57PM +0100, Milan Broz wrote:
> > But it doesn't fix the read-only snapshot issue and I guess there will be
> > the same problem with read-only MD code too.
> > (so the 2) issue here https://lkml.org/lkml/2011/2/12/209).
So, the problem is caused by dm opening members rw even for ro
devices, right?
> I am not sure if this is complete fix... note that:
> - what happens during mirror resync and read-only log?
> - for COW, it there situation we need to update header in read-oly mode? (invalidated snap?)
But if the underlying device is marked ro, dm shouldn't update it at
all. The device should be opened ro and ro policy should be enforced.
Thanks.
--
tejun
next prev parent reply other threads:[~2011-02-14 14:09 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-13 2:02 block device read-only handling regression in 2.6.38-rc4 (bisected) Milan Broz
2011-02-13 10:58 ` [PATCH] loop: clear read-only flag in loop_clr_fd Tao Ma
2011-02-13 14:11 ` Milan Broz
2011-02-13 15:05 ` Tao Ma
2011-02-13 16:44 ` Milan Broz
2011-02-14 10:30 ` Tejun Heo
2011-02-14 11:47 ` Milan Broz
2011-02-14 13:14 ` [PATCH][RFC] dm: Do not open log and cow device read-write for read-only mappings Milan Broz
2011-02-14 14:09 ` Tejun Heo [this message]
2011-02-14 14:23 ` Milan Broz
2011-02-14 15:44 ` Tejun Heo
2011-02-14 23:15 ` NeilBrown
2011-02-15 2:03 ` [dm-devel] " Alasdair G Kergon
2011-02-15 12:17 ` Milan Broz
2011-02-15 12:46 ` Alasdair G Kergon
2011-02-15 15:20 ` Tejun Heo
2011-02-15 15:46 ` Alasdair G Kergon
2011-02-15 15:50 ` Tejun Heo
2011-02-15 16:05 ` Milan Broz
2011-02-15 16:12 ` Tejun Heo
2011-02-15 16:36 ` Milan Broz
2011-02-15 16:41 ` Tejun Heo
2011-02-15 16:56 ` Alasdair G Kergon
2011-02-16 8:46 ` Tejun Heo
2011-02-15 16:58 ` Milan Broz
2011-02-16 8:39 ` Tejun Heo
2011-02-15 15:16 ` [PATCH] Return EROFS if read-only detected on block device Milan Broz
2011-02-14 14:39 ` [dm-devel] [PATCH][RFC] dm: Do not open log and cow device read-write for read-only mappings Alasdair G Kergon
2011-02-14 14:07 ` [PATCH] loop: clear read-only flag in loop_clr_fd Tejun Heo
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=20110214140940.GM18742@htj.dyndns.org \
--to=tj@kernel.org \
--cc=axboe@kernel.dk \
--cc=dm-devel@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mbroz@redhat.com \
--cc=tm@tao.ma \
/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
all inboxes | Powered by JetHome®