From: Jan Kara <jack@suse.cz>
To: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>, Dmitry Monakhov <dmonakhov@openvz.org>,
linux-ext4@vger.kernel.org
Subject: Re: REGRESSION: [PATCH 04/12] ext4: Disable merging of uninitialized extents
Date: Thu, 14 Feb 2013 22:32:50 +0100 [thread overview]
Message-ID: <20130214213250.GA4887@quack.suse.cz> (raw)
In-Reply-To: <20130214190555.GA6641@thunk.org>
On Thu 14-02-13 14:05:55, Ted Tso wrote:
> On Thu, Feb 14, 2013 at 05:11:16PM +0100, Jan Kara wrote:
> > OK, so I've debugged this. It wasn't actually that hard. The problem is
> > that mpage_da_map_and_submit() prepares extent with e.g. 256 blocks but
> > later we submit a shorter bio e.g. because it cannot carry that many pages.
> > So ->end_io is called only for first 128 blocks or so. I spotted this
> > problem already before, just it didn't come up when Ted sent me this bug
> > report.
>
> So can we get a corruption without these patches, but it was a lot
> harder to hit that case before?
When the bio is shorter we just need to split the unwritten extent when
processing end_io callback. That is properly handled after Dmitry's fixes
so corruption can happen only when we are close to ENOSPC and the split
fails. Now we started seeing the split is happening because one of the
patches added the warning that the split from end_io is happening...
Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
next prev parent reply other threads:[~2013-02-14 21:32 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-18 12:00 [PATCH 0/12 v2] ext4: Several simplifications and fixes Jan Kara
2013-01-18 12:00 ` [PATCH 01/12] ext4: Always use ext4_bio_write_page() for writeout Jan Kara
2013-01-28 14:31 ` Theodore Ts'o
2013-01-18 12:00 ` [PATCH 02/12] ext4: Use redirty_page_for_writepage() in ext4_bio_write_page() Jan Kara
2013-01-28 14:34 ` Theodore Ts'o
2013-01-18 12:00 ` [PATCH 03/12] ext4: Remove bogus wait for unwritten extents in ext4_ind_direct_IO Jan Kara
2013-01-22 11:11 ` Dmitry Monakhov
2013-01-22 13:44 ` Jan Kara
2013-01-22 14:12 ` Dmitry Monakhov
2013-01-22 15:21 ` Jan Kara
2013-01-22 14:22 ` Zheng Liu
2013-01-22 15:22 ` Jan Kara
2013-01-22 16:00 ` Zheng Liu
2013-01-22 23:14 ` Jan Kara
2013-01-23 6:11 ` Zheng Liu
2013-01-23 9:42 ` Jan Kara
2013-01-18 12:00 ` [PATCH 04/12] ext4: Disable merging of uninitialized extents Jan Kara
2013-01-24 9:49 ` Dmitry Monakhov
2013-01-24 15:12 ` Jan Kara
2013-01-24 15:32 ` Dmitry Monakhov
2013-01-28 14:36 ` Theodore Ts'o
2013-01-28 15:02 ` Dmitry Monakhov
2013-01-28 15:38 ` Theodore Ts'o
2013-01-29 7:41 ` Dmitry Monakhov
2013-01-29 8:37 ` Zheng Liu
2013-01-31 7:47 ` Dmitry Monakhov
2013-01-31 12:39 ` Jan Kara
2013-01-31 14:09 ` Dmitry Monakhov
2013-01-31 16:54 ` Theodore Ts'o
2013-02-09 17:10 ` REGRESSION: " Theodore Ts'o
2013-02-12 21:58 ` Jan Kara
2013-02-13 4:57 ` Theodore Ts'o
2013-02-13 7:26 ` Dmitry Monakhov
2013-02-13 15:08 ` Merge window planning for ext4 and Ted's vacation Theodore Ts'o
2013-02-14 10:47 ` REGRESSION: [PATCH 04/12] ext4: Disable merging of uninitialized extents Jan Kara
2013-02-14 16:11 ` Jan Kara
2013-02-14 19:05 ` Theodore Ts'o
2013-02-14 21:32 ` Jan Kara [this message]
2013-01-18 12:00 ` [PATCH 05/12] ext4: Remove unnecessary wait for extent conversion in ext4_fallocate() Jan Kara
2013-01-18 12:00 ` [PATCH 06/12] ext4: Move work from io_end to inode Jan Kara
2013-01-28 14:45 ` Theodore Ts'o
2013-01-18 12:00 ` [PATCH 07/12] ext4: Simplify list handling in ext4_do_flush_completed_IO() Jan Kara
2013-01-28 14:51 ` Theodore Ts'o
2013-01-18 12:00 ` [PATCH 08/12] ext4: Remove __ext4_journalled_writepage() from mpage_da_submit_io() Jan Kara
2013-01-28 14:40 ` Theodore Ts'o
2013-01-18 12:00 ` [PATCH 09/12] ext4: Dirty page has always buffers attached Jan Kara
2013-01-28 17:55 ` Theodore Ts'o
2013-01-18 12:00 ` [PATCH 10/12] ext4: Simplify mpage_add_bh_to_extent() Jan Kara
2013-01-28 18:06 ` Theodore Ts'o
2013-01-18 12:00 ` [PATCH 11/12] ext4: Make ext4_bio_writepage() handle unprepared buffers Jan Kara
2013-01-29 1:59 ` Theodore Ts'o
2013-01-18 12:00 ` [PATCH 12/12] ext4: Fix ext4_writepage() to achieve data=ordered guarantees Jan Kara
2013-01-29 2:08 ` Theodore Ts'o
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