linux-ext4 - Re: [Bug 25352] New: resizing ext4 will corrupt filesystem

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Message-ID: <20101221033209.GA6924@thunk.org>
Date:	Mon, 20 Dec 2010 22:32:09 -0500
From:	Ted Ts'o <tytso@....edu>
To:	bugzilla-daemon@...zilla.kernel.org
Cc:	linux-ext4@...r.kernel.org, Lukas Czerner <lczerner@...hat.com>
Subject: Re: [Bug 25352] New: resizing ext4 will corrupt filesystem

On Mon, Dec 20, 2010 at 08:56:46PM +0000, bugzilla-daemon@...zilla.kernel.org wrote:
> 
> Using resize2fs on an ext4 will result in a corrupted filesystem. This is a
> regression (obviously).

Yes, this is a regression new to 2.6.37-rc1, which was introduced by
commit a31437b85: ext4: use sb_issue_zeroout in setup_new_group_blocks.

When we replaced the loop zero'ing the inode table blocks with
sb_issue_zeroout, we accidentally also removed this little tidbit:

-               ext4_set_bit(bit, bh->b_data);

... which was responsible for setting the block allocation bitmap to
reserve the block descriptor blocks and inode table blocks.  Oops...

I believe this patch should fix things.

						- Ted

View attachment "0001-ext4-fix-on-line-resizing-regression.patch" of type "text/x-diff" (1448 bytes)