linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Grzegorz Kulewski <kangur@polcom.net>
To: Dave Hansen <haveblue@us.ibm.com>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	herbert@13thfloor.at, viro@ftp.linux.org.uk
Subject: Re: [RFC][PATCH 00/20] Mount writer count and read-only bind mounts (v2)
Date: Sat, 17 Jun 2006 01:29:42 +0200 (CEST)	[thread overview]
Message-ID: <Pine.LNX.4.63.0606170125110.14464@alpha.polcom.net> (raw)
In-Reply-To: <20060616231213.D4C5D6AF@localhost.localdomain>

On Fri, 16 Jun 2006, Dave Hansen wrote:
> The following series implements read-only bind mounts.  This feature
> allows a read-only view into a read-write filesystem.

Thanks, I like this idea very much. I think I have found at least one good
use for it even before it is merged. :-)

But...

> One note: the previous patches all worked this way:
>
> 	mount --bind -o ro /source /dest
>
> These patches have changed that behavior.  It now requires two steps:
>
> 	mount --bind /source /dest
> 	mount -o remount,ro  /dest

Isn't this some kind of security risk (at least in my planned use)? I mean 
- for a small fraction of second somebody seeing /dest can write 
/source... No?


Thanks,

Grzegorz Kulewski


  parent reply	other threads:[~2006-06-16 23:29 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-06-16 23:12 [RFC][PATCH 00/20] Mount writer count and read-only bind mounts (v2) Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 01/20] prepare for write access checks: collapse if() Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 02/20] r/o bind mount prepwork: move open_namei()'s vfs_create() Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 03/20] Add vfsmount writer count Dave Hansen
2006-06-18 18:33   ` Al Viro
2006-06-19 17:02     ` Dave Hansen
2006-06-20 21:20       ` Al Viro
2006-06-22 17:01         ` Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 04/20] elevate mnt writers for callers of vfs_mkdir() Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 05/20] elevate write count during entire ncp_ioctl() Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 07/20] elevate mount count for extended attributes Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 06/20] sys_symlinkat() elevate write count around vfs_symlink() Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 08/20] sys_linkat(): elevate write count around vfs_link() Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 09/20] mount_is_safe(): add comment Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 10/20] unix_find_other() elevate write count for touch_atime() Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 11/20] elevate write count over calls to vfs_rename() Dave Hansen
2006-06-18 18:23   ` Al Viro
2006-06-19 17:18     ` Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 12/20] tricky: elevate write count files are open()ed Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 13/20] elevate writer count for do_sys_truncate() Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 14/20] elevate write count for do_utimes() Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 15/20] elevate write count for do_sys_utime() and touch_atime() Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 16/20] sys_mknodat(): elevate write count for vfs_mknod/create() Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 17/20] elevate mnt writers for vfs_unlink() callers Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 18/20] do_rmdir(): elevate write count Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 19/20] elevate writer count for custom 'struct file' Dave Hansen
2006-06-16 23:12 ` [RFC][PATCH 20/20] honor r/w changes at do_remount() time Dave Hansen
2006-06-18 18:36   ` Al Viro
2006-06-19 16:45     ` Dave Hansen
2006-06-16 23:29 ` Grzegorz Kulewski [this message]
2006-06-16 23:41   ` [RFC][PATCH 00/20] Mount writer count and read-only bind mounts (v2) Dave Hansen
2006-06-17  0:10     ` Grzegorz Kulewski
2006-06-17  3:35       ` Herbert Poetzl
2006-06-17  9:36         ` Jan Engelhardt
2006-06-17 13:29           ` Herbert Poetzl

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=Pine.LNX.4.63.0606170125110.14464@alpha.polcom.net \
    --to=kangur@polcom.net \
    --cc=haveblue@us.ibm.com \
    --cc=herbert@13thfloor.at \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=viro@ftp.linux.org.uk \
    /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).