From: Ted Ts'o <tytso@mit.edu>
To: Andreas Dilger <adilger@dilger.ca>
Cc: Ext4 Developers List <linux-ext4@vger.kernel.org>
Subject: Re: [PATCH] ext4: Add mount options in superblock
Date: Tue, 3 Aug 2010 14:31:47 -0400 [thread overview]
Message-ID: <20100803183147.GC9453@thunk.org> (raw)
In-Reply-To: <C270D256-EC9B-4449-9CBA-4C7DD51D0B22@dilger.ca>
On Tue, Aug 03, 2010 at 11:55:39AM -0600, Andreas Dilger wrote:
> On 2010-08-01, at 21:15, Theodore Ts'o wrote:
> > Allow mount options to be stored in the superblock. Also add default
> > mount option bits for nobarrier, block_validity, discard, and nodelalloc.
>
> Don't we already store mount options in s_default_mount_opts? It
> seems more efficient to store them as binary flags instead of as a
> string.
For mount options that are going to be around for a long time, this
makes sense and it is indeed the preferred mechanism. The problem is
that if we are adding and removing mount options, perhaps for internal
testing purposes using binary bitfields don't work as well, because
(a) it means we have to synchronize e2fsprogs with the kernel updates,
and (b) once used, it's hard to recycle a binary bit position since
there might be old file systems around. So the 64 byte character
array is intended to be used as an adjunct for the binary bitfield.
- Ted
prev parent reply other threads:[~2010-08-03 18:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-02 3:15 [PATCH] ext4: Add mount options in superblock Theodore Ts'o
2010-08-03 17:55 ` Andreas Dilger
2010-08-03 18:31 ` Ted Ts'o [this message]
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=20100803183147.GC9453@thunk.org \
--to=tytso@mit.edu \
--cc=adilger@dilger.ca \
--cc=linux-ext4@vger.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).