From: Jan Kara <jack@suse.cz>
To: Boaz Harrosh <bharrosh@panasas.com>
Cc: Jan Kara <jack@suse.cz>,
"Darrick J. Wong" <darrick.wong@oracle.com>,
NeilBrown <neilb@suse.de>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Theodore Ts'o <tytso@mit.edu>,
linux-ext4 <linux-ext4@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [RFC PATCH 1/2] bdi: Create a flag to indicate that a backing device needs stable page writes
Date: Thu, 1 Nov 2012 23:42:16 +0100 [thread overview]
Message-ID: <20121101224216.GA31937@quack.suse.cz> (raw)
In-Reply-To: <5092B060.9070604@panasas.com>
On Thu 01-11-12 10:24:48, Boaz Harrosh wrote:
> On 11/01/2012 01:59 AM, Jan Kara wrote:
> <>
> > (all block device inodes share one superblock).
> >
>
> Really? that is not so good is it, for other obvious reasons.
> Why is it not one superblock per BDI? That would be more obvious
> to me.
>
> > Thoughts?
>
> It's a really bad design. I think it is worth fixing. For the above
> problem, as well as a much better fit with our current thread-per-bdi,
> and the rest of the Kernel model. No?
So the fact that there is one superblock of virtual filesystem containing
all block device inodes is inconvenient at times (that's why we have to
have inode_to_bdi() function in fs/fs-writeback.c) but OTOH you cannot
really attach these virtual block device inodes (note that these are
different from an inode for an object say /dev/sda in the filesystem)
anywhere else and having one sb per block device would really be an
overkill.
Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
next prev parent reply other threads:[~2012-11-01 22:42 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-26 10:19 semi-stable page writes Darrick J. Wong
2012-10-27 1:35 ` [RFC PATCH 1/2] bdi: Create a flag to indicate that a backing device needs stable " Darrick J. Wong
2012-10-29 18:13 ` Jan Kara
2012-10-29 18:30 ` Jan Kara
2012-10-29 23:48 ` NeilBrown
2012-10-30 0:10 ` Jan Kara
2012-10-30 0:34 ` NeilBrown
2012-10-30 13:38 ` Jan Kara
2012-10-30 21:49 ` NeilBrown
2012-10-30 4:10 ` Martin K. Petersen
2012-10-30 4:48 ` NeilBrown
2012-10-30 12:19 ` Martin K. Petersen
2012-10-30 20:14 ` Darrick J. Wong
2012-10-30 22:14 ` NeilBrown
2012-10-30 23:58 ` Boaz Harrosh
2012-10-31 8:56 ` Darrick J. Wong
2012-10-31 11:56 ` Jan Kara
2012-10-31 19:36 ` Darrick J. Wong
2012-10-31 23:12 ` Boaz Harrosh
2012-11-01 5:51 ` Darrick J. Wong
2012-11-01 6:25 ` Boaz Harrosh
2012-11-01 8:59 ` Jan Kara
2012-11-01 17:24 ` Boaz Harrosh
2012-11-01 22:42 ` Jan Kara [this message]
2012-10-30 22:40 ` Boaz Harrosh
2012-10-27 1:36 ` [RFC PATCH 2/2] mm: Gate stable page writes on the bdi flag Darrick J. Wong
2012-10-29 18:28 ` Jan Kara
2012-10-31 8:58 ` Darrick J. Wong
2012-10-29 22:01 ` semi-stable page writes Dave Chinner
2012-10-30 1:00 ` Theodore Ts'o
2012-10-30 23:30 ` Dave Chinner
2012-10-31 11:45 ` Jan Kara
2012-10-30 20:40 ` Darrick J. Wong
2012-10-30 23:43 ` Dave Chinner
2012-10-31 9:05 ` Darrick J. Wong
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=20121101224216.GA31937@quack.suse.cz \
--to=jack@suse.cz \
--cc=bharrosh@panasas.com \
--cc=darrick.wong@oracle.com \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=martin.petersen@oracle.com \
--cc=neilb@suse.de \
--cc=tytso@mit.edu \
/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).