From: antlists <antlists@youngman.org.uk>
To: John Stoffel <john@stoffel.org>, Danny Shih <dannyshih@synology.com>
Cc: axboe@kernel.dk, agk@redhat.com, snitzer@redhat.com,
dm-devel@redhat.com, song@kernel.org,
linux-block@vger.kernel.org, linux-raid@vger.kernel.org
Subject: Re: [PATCH 1/4] block: introduce submit_bio_noacct_add_head
Date: Wed, 30 Dec 2020 17:53:44 +0000 [thread overview]
Message-ID: <1b6c4709-8409-a73f-d3f0-4b4cf19bfae1@youngman.org.uk> (raw)
In-Reply-To: <24556.45969.276771.345181@quad.stoffel.home>
On 30/12/2020 17:06, John Stoffel wrote:
> Danny> "Provide a way for stacking block device to re-submit
>
> Danny> the bio which should be handled first."
>
> Danny> I will fix it.
>
> Great, though my second question is*why* it needs to be handled
> first? What is the difference between stacked and un-stacked devices
> and how could it be done in a way that doesn't require a seperate
> function like this?
Is this anything to do with what's on my mind as a database guy? I've
heard that things like RAID and LVM have difficulty providing write
barriers.
I want to be confident that, at EVERY level of the stack, I can put a
barrier in that guarantees that everything written by user-space BEFORE
the barrier is handled before anything written AFTER the barrier. That
way, I can be confident that, after a problem, I know whether I can
safely roll the log forward or back.
Cheers,
Wol
next prev parent reply other threads:[~2020-12-30 17:54 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-29 9:18 [PATCH 0/4] Fix order when split bio and send remaining back to itself dannyshih
2020-12-29 9:18 ` [PATCH 1/4] block: introduce submit_bio_noacct_add_head dannyshih
2020-12-30 0:00 ` John Stoffel
2020-12-30 9:51 ` Danny Shih
2020-12-30 17:06 ` John Stoffel
2020-12-30 17:53 ` antlists [this message]
2020-12-30 11:35 ` antlists
2020-12-30 16:53 ` John Stoffel
2020-12-29 9:18 ` [PATCH 2/4] block: use submit_bio_noacct_add_head for split bio sending back dannyshih
2020-12-29 9:18 ` [PATCH 3/4] dm: " dannyshih
2020-12-29 9:18 ` [PATCH 4/4] md: " dannyshih
2020-12-30 23:34 ` [PATCH 0/4] Fix order when split bio and send remaining back to itself Mike Snitzer
2020-12-31 8:28 ` Danny Shih
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=1b6c4709-8409-a73f-d3f0-4b4cf19bfae1@youngman.org.uk \
--to=antlists@youngman.org.uk \
--cc=agk@redhat.com \
--cc=axboe@kernel.dk \
--cc=dannyshih@synology.com \
--cc=dm-devel@redhat.com \
--cc=john@stoffel.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-raid@vger.kernel.org \
--cc=snitzer@redhat.com \
--cc=song@kernel.org \
/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).