[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <20100803183147.GC9453@thunk.org>
Date: Tue, 3 Aug 2010 14:31:47 -0400
From: Ted Ts'o <tytso@....edu>
To: Andreas Dilger <adilger@...ger.ca>
Cc: Ext4 Developers List <linux-ext4@...r.kernel.org>
Subject: Re: [PATCH] ext4: Add mount options in superblock
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
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists