From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH] wake up s_wait_unfrozen when ->freeze_fs fails
Date: Tue, 6 Dec 2011 10:20:31 -0500
Message-ID: <20111206152031.GA15613@infradead.org>
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To: Kazuya Mio <k-mio@sx.jp.nec.com>
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On Thu, Dec 01, 2011 at 04:51:07PM +0900, Kazuya Mio wrote:
> dd slept infinitely when fsfeeze failed because of EIO.
> To fix this problem, if ->freeze_fs fails, freeze_super() wakes up
> the tasks waiting for the filesystem to become unfrozen.
> 
> When s_frozen isn't SB_UNFROZEN in __generic_file_aio_write(),
> the function sleeps until FITHAW ioctl wakes up s_wait_unfrozen.
> 
> However, if ->freeze_fs fails, s_frozen is set to SB_UNFROZEN and then
> freeze_super() returns an error number. In this case, FITHAW ioctl returns
> EINVAL because s_frozen is already SB_UNFROZEN. There is no way to wake up
> s_wait_unfrozen, so __generic_file_aio_write() sleeps infinitely.

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

You don't happen to have testcase (e.g. by using dm-fauly or XFS error
injection) that we could add to xfstests for this?