From mboxrd@z Thu Jan  1 00:00:00 1970
From: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Subject: [PATCH 0/2] fsfreeze: check ioctls
Date: Thu, 21 Jul 2011 11:32:15 +0900
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Cc: Christoph Hellwig <hch@lst.de>, Eric Sandeen <sandeen@redhat.com>,
	Josef Bacik <josef@redhat.com>, linux-fsdevel@vger.kernel.org
To: Al Viro <viro@ZenIV.linux.org.uk>
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The current fsfreeze API lacks a method to check the current freeze
status of a superblock. One might be tempted to think that a new vfs
ioctl is all we need, but with the current implemetation of fsfreeze it
it is possible to umount a freezed filesystem, which means that the only
way to check the freeze status is through the block device. For a moment
I thought I could get without the vfs version but then I realized that
the block device ioctl would not play well with btrfs.

Because of all of the above I ended up implementing both. Al also
suggested [1] a thaw-by-block-device ioctl which I am currently working
on.

[1] http://marc.info/?l=linux-kernel&m=125361768208298&w=2