From: KaiGai Kohei <kaigai@kaigai.gr.jp>
To: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd <linux-mtd@lists.infradead.org>,
Glen Johnson <gjohnson@valcom.com>,
KaiGai Kohei <kaigai@ak.jp.nec.com>
Subject: Re: mkfs.jffs2 not compiling, which acl.h?
Date: Sun, 10 Dec 2006 01:40:56 +0900 [thread overview]
Message-ID: <457AE718.1090707@kaigai.gr.jp> (raw)
In-Reply-To: <1165505164.5253.370.camel@pmac.infradead.org>
I'm sorry for delayed responding.
> Actually, I'm not entirely sure what this code is doing at all -- isn't
> it interpreting on-disk xattrs representing ACLs assuming that they're
> in the same format as ext3 uses? If you use mkfs.jffs2 on a big-endian
> system, actually reading _from_ a jffs2 filesystem, does it do the right
> thing? What about from other file systems?
Because the on-disk xattr representation which holds any ACLs is
interpreted into _common_ format in the kernel, the user space
application including mkfs.jffs2 does not need to be conscious
the differences between filesystems or endians.
See, fs/xattr_acl.c in the kernel.
Any filesystem (excluding xfs) calls posix_acl_to_xattr() to interpret
the in-kernel representation of ACLs before returning it into userspace.
The common format is defined as a leading 'posix_acl_xattr_header' and
an array of 'posix_acl_xattr_entry'. All of them are represented in
little-endian ordering.
Thus, we can assume the same format as ext3 (and any filesystem) uses.
Is it OK?
Thanks,
--
KaiGai Kohei <kaigai@kaigai.gr.jp>
next prev parent reply other threads:[~2006-12-09 16:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-06 13:56 mkfs.jffs2 not compiling, which acl.h? Glen Johnson
2006-12-06 14:02 ` Ricard Wanderlof
2006-12-06 14:42 ` Glen Johnson
2006-12-06 16:12 ` Ricard Wanderlof
2006-12-07 15:26 ` David Woodhouse
2006-12-07 15:56 ` Glen Johnson
2006-12-09 16:40 ` KaiGai Kohei [this message]
2006-12-10 11:53 ` David Woodhouse
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=457AE718.1090707@kaigai.gr.jp \
--to=kaigai@kaigai.gr.jp \
--cc=dwmw2@infradead.org \
--cc=gjohnson@valcom.com \
--cc=kaigai@ak.jp.nec.com \
--cc=linux-mtd@lists.infradead.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.