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From: Anton Altaparmakov <aia21@cam.ac.uk>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <hansendc@us.ibm.com>,
	linux-kernel@vger.kernel.org, hch@infradead.org
Subject: Re: [PATCH 21/22] honor r/w changes at do_remount() time
Date: Sat, 10 Feb 2007 00:29:40 +0000	[thread overview]
Message-ID: <413B65F6-2730-450A-9CD7-B7FE7A8ED961@cam.ac.uk> (raw)
In-Reply-To: <20070209152219.fa61d152.akpm@linux-foundation.org>

On 9 Feb 2007, at 23:22, Andrew Morton wrote:
> On Fri, 09 Feb 2007 14:53:44 -0800
> Dave Hansen <hansendc@us.ibm.com> wrote:
>
>> This is the core of the read-only bind mount patch set.
>
> Who wants read-only bind mounts, and for what reason?

On our local mirror server (mirrors just under 3TiB worth of stuff)  
we hold all data on r/w mounted storage in a private location in the  
file tree.  (Note the server runs Solaris 10 not Linux or the  
following would not be possible at present...)

We then bind mount (i.e. loopback mount on Solaris) various  
directories from inside the private paths to various other locations  
so for example we create /export/ftp/pub/* where "*" are directories  
we want to export via FTP and we do all of those as read-only bind  
mounts.  This gives us that little bit of extra confidence that no- 
one from the outside can cause any writes to happen to our mirrored  
data.  We do similar for NFS by creating lots of read-only bind  
mounts in /* that again point into the private locations.

It would be nice if the Linux box that we have that is a copy/backup  
of the Solaris box could do the same rather than have all the bind  
mounts be read-write because we need the storage in the private  
locations to be writable.

Best regards,

	Anton

  parent reply	other threads:[~2007-02-10  0:30 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-09 22:53 [PATCH 01/22] filesystem helpers for custom 'struct file's Dave Hansen
2007-02-09 22:53 ` [PATCH 02/22] r/o bind mounts: add vfsmount writer counts Dave Hansen
2007-02-09 23:41   ` Eric Dumazet
2007-02-10  0:10     ` Dave Hansen
2007-02-09 22:53 ` [PATCH 03/22] record when sb_writer_count elevated for inode Dave Hansen
2007-02-09 22:53 ` [PATCH 04/22] elevate writer count for chown and friends Dave Hansen
2007-02-09 22:53 ` [PATCH 05/22] elevate mnt writers for callers of vfs_mkdir() Dave Hansen
2007-02-09 22:53 ` [PATCH 06/22] elevate write count during entire ncp_ioctl() Dave Hansen
2007-02-09 22:53 ` [PATCH 07/22] elevate write count for link and symlink calls Dave Hansen
2007-02-09 22:53 ` [PATCH 08/22] elevate mount count for extended attributes Dave Hansen
2007-02-09 22:53 ` [PATCH 09/22] mount_is_safe(): add comment Dave Hansen
2007-02-09 22:53 ` [PATCH 10/22] unix_find_other() elevate write count for touch_atime() Dave Hansen
2007-02-09 22:53 ` [PATCH 12/22] elevate write count files are open()ed Dave Hansen
2007-02-13  5:11   ` Andrew Morton
2007-02-13 16:58     ` Dave Hansen
2007-02-13 17:58       ` Andrew Morton
2007-02-14  0:17         ` Dave Hansen
2007-02-09 22:53 ` [PATCH 11/22] elevate write count over calls to vfs_rename() Dave Hansen
2007-02-09 22:53 ` [PATCH 13/22] elevate writer count for do_sys_truncate() Dave Hansen
2007-02-09 22:53 ` [PATCH 14/22] elevate write count for do_utimes() Dave Hansen
2007-02-09 22:53 ` [PATCH 15/22] elevate write count for do_sys_utime() and touch_atime() Dave Hansen
2007-02-09 22:53 ` [PATCH 16/22] sys_mknodat(): elevate write count for vfs_mknod/create() Dave Hansen
2007-02-09 22:53 ` [PATCH 17/22] elevate mnt writers for vfs_unlink() callers Dave Hansen
2007-02-09 22:53 ` [PATCH 18/22] do_rmdir(): elevate write count Dave Hansen
2007-02-09 22:53 ` [PATCH 19/22] elevate writer count for custom struct_file Dave Hansen
2007-02-09 22:53 ` [PATCH 20/22] [PATCH] gfs: check nlink count Dave Hansen
2007-02-09 22:53 ` [PATCH 21/22] honor r/w changes at do_remount() time Dave Hansen
2007-02-09 23:22   ` Andrew Morton
2007-02-10  0:00     ` Dave Hansen
2007-02-10  0:29     ` Anton Altaparmakov [this message]
2007-02-10  9:54     ` Jan Engelhardt
2007-02-09 22:53 ` [PATCH 22/22] kill open files traverse on remount ro Dave Hansen
2007-02-09 23:18 ` [PATCH 01/22] filesystem helpers for custom 'struct file's Andrew Morton

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