From: Dave Hansen <haveblue@us.ibm.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-kernel@vger.kernel.org, viro@ftp.linux.org.uk,
herbert@13thfloor.at
Subject: Re: [PATCH 06/28] reintroduce list of vfsmounts over superblock
Date: Fri, 04 Aug 2006 14:47:08 -0700 [thread overview]
Message-ID: <1154728028.10109.47.camel@localhost.localdomain> (raw)
In-Reply-To: <20060803143953.GD920@infradead.org>
On Thu, 2006-08-03 at 15:39 +0100, Christoph Hellwig wrote:
> On Tue, Aug 01, 2006 at 04:52:44PM -0700, Dave Hansen wrote:
> >
> > We're moving a big chunk of the burden of keeping people from
> > writing to r/o filesystems from the superblock into the
> > vfsmount. This requires that we consult the superblock's
> > vfsmounts when things like remounts occur.
> >
> > So, introduce a list of vfsmounts hanging off the superblock.
> > We'll use this in a bit.
>
> I don't think we'll need it. We really need to keep is someone writing
> to this vfsmount counters in addition to is someone writing to this sb.
This one was a direct request from Al:
http://article.gmane.org/gmane.linux.kernel/421029
> BTW, it might be worth doing the following:
> * reintroduce the list of vfsmounts over given superblock (protected
> by vfsmount_lock)
...
So, I assume that there are some evil plans in the future for this as
well.
> In fact there are cases were we want a superblock to be writeable to
> without any view into it being writeable, e.g. for journal recovery.
Note that, as it stands now, the vfsmount has a flag which duplicates
the superblock r/o flag. It is perfectly fine to do that journal
recovery by making the superblock r/w, but without telling any of the
mounts about it. All of the write requests will get blocked by the
mount flag, and no one will ever see that the superblock changed state.
-- Dave
next prev parent reply other threads:[~2006-08-04 21:47 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-01 23:52 [PATCH 00/28] Mount writer count and read-only bind mounts (v5) Dave Hansen
2006-08-01 23:52 ` [PATCH 01/28] prepare for write access checks: collapse if() Dave Hansen
2006-08-03 14:32 ` Christoph Hellwig
2006-08-01 23:52 ` [PATCH 02/28] r/o bind mount prepwork: move open_namei()'s vfs_create() Dave Hansen
2006-08-03 14:33 ` Christoph Hellwig
2006-08-01 23:52 ` [PATCH 03/28] unlink: monitor i_nlink Dave Hansen
2006-08-03 14:35 ` Christoph Hellwig
2006-08-01 23:52 ` [PATCH 04/28] OCFS2 is screwy Dave Hansen
2006-08-02 2:14 ` Mark Fasheh
2006-08-02 3:19 ` [PATCH 04/28] OCFS2 is (not) screwy Dave Hansen
2006-08-02 3:21 ` [PATCH 04/28] OCFS2 is screwy Dave Hansen
2006-08-02 4:34 ` Mark Fasheh
2006-08-03 0:20 ` Mark Fasheh
2006-08-04 21:01 ` [PATCH] clean up OCFS2 nlink handling Dave Hansen
2006-08-04 21:38 ` Mark Fasheh
2006-08-01 23:52 ` [PATCH 05/28] monitor zeroing of i_nlink Dave Hansen
2006-08-01 23:52 ` [PATCH 06/28] reintroduce list of vfsmounts over superblock Dave Hansen
2006-08-03 14:39 ` Christoph Hellwig
2006-08-04 21:47 ` Dave Hansen [this message]
2006-08-01 23:52 ` [PATCH 07/28] Add vfsmount writer count Dave Hansen
2006-08-01 23:52 ` [PATCH 09/28] kill open files traverse on remount ro Dave Hansen
2006-08-01 23:52 ` [PATCH 08/28] record when sb_writer_count elevated for inode Dave Hansen
2006-08-01 23:52 ` [PATCH 10/28] increment sb writer count when nlink hits zero Dave Hansen
2006-08-01 23:52 ` [PATCH 11/28] elevate writer count for chown and friends Dave Hansen
2006-08-01 23:52 ` [PATCH 12/28] elevate mnt writers for callers of vfs_mkdir() Dave Hansen
2006-08-01 23:52 ` [PATCH 14/28] sys_symlinkat() elevate write count around vfs_symlink() Dave Hansen
2006-08-01 23:52 ` [PATCH 13/28] elevate write count during entire ncp_ioctl() Dave Hansen
2006-08-01 23:52 ` [PATCH 15/28] elevate mount count for extended attributes Dave Hansen
2006-08-01 23:52 ` [PATCH 16/28] sys_linkat(): elevate write count around vfs_link() Dave Hansen
2006-08-01 23:52 ` [PATCH 17/28] mount_is_safe(): add comment Dave Hansen
2006-08-01 23:52 ` [PATCH 18/28] unix_find_other() elevate write count for touch_atime() Dave Hansen
2006-08-01 23:52 ` [PATCH 19/28] elevate write count over calls to vfs_rename() Dave Hansen
2006-08-01 23:52 ` [PATCH 20/28] tricky: elevate write count files are open()ed Dave Hansen
2006-08-01 23:52 ` [PATCH 21/28] elevate writer count for do_sys_truncate() Dave Hansen
2006-08-01 23:52 ` [PATCH 22/28] elevate write count for do_utimes() Dave Hansen
2006-08-01 23:52 ` [PATCH 23/28] elevate write count for do_sys_utime() and touch_atime() Dave Hansen
2006-08-01 23:52 ` [PATCH 24/28] sys_mknodat(): elevate write count for vfs_mknod/create() Dave Hansen
2006-08-01 23:52 ` [PATCH 25/28] elevate mnt writers for vfs_unlink() callers Dave Hansen
2006-08-01 23:52 ` [PATCH 26/28] do_rmdir(): elevate write count Dave Hansen
2006-08-01 23:53 ` [PATCH 27/28] elevate writer count for custom 'struct file' Dave Hansen
2006-08-03 14:42 ` Christoph Hellwig
2006-08-11 20:31 ` Dave Hansen
2006-08-01 23:53 ` [PATCH 28/28] honor r/w changes at do_remount() time Dave Hansen
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