linux-ext4 - Re: [PATCH 0/9 v3] ext4: Punch hole and DAX fixes

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Date:	Mon, 9 Nov 2015 17:22:56 +0100
From:	Jan Kara <jack@...e.cz>
To:	"Boylston, Brian" <brian.boylston@....com>
Cc:	Jan Kara <jack@...e.com>, Ted Tso <tytso@....edu>,
	"linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org>,
	Ross Zwisler <ross.zwisler@...ux.intel.com>,
	"dan.j.williams@...el.com" <dan.j.williams@...el.com>
Subject: Re: [PATCH 0/9 v3] ext4: Punch hole and DAX fixes

  Hi,

On Fri 06-11-15 17:57:04, Boylston, Brian wrote:
> I've written a test tool (included below) that exercises page faults on
> hole-y portions of an mmapped file.  The file is created, sized using
> various methods, mmapped, and then two threads race to write a marker to
> different offsets within each mapped page.  Once the threads have
> finished marking each page, the pages are checked for the presence of
> the markers.
> 
> With vanilla 4.2 and 4.3 kernels, this test easily exposes corruption on
> pmem-backed, DAX-mounted xfs and ext4 file systems.
> 
> With 4.3 and this ext4 patch set, the data corruption is still seen:
> 
> $ ./holetest -f /pmem1/brian/holetest 1000
> holetest r207

Thanks for the test. I'll try to reproduce locally and have a look why
my block zeroing patch didn't work as expected.

								Honza
> 
> INFO: zero-filled test...
> INFO: sz = 3e800000, npages = 256000
> INFO: vastart = 00007f2ad0bd0000
> INFO: thread 0 is 7f2ad0bcf700
> INFO: thread 1 is 7f2ad03ce700
> INFO: 0 error(s) detected
> 
> INFO: posix_fallocate test...
> INFO: sz = 3e800000, npages = 256000
> INFO: vastart = 00007f2ad0bd0000
> INFO: thread 0 is 7f2ad03ce700
> INFO: thread 1 is 7f2ad0bcf700
> INFO: 0 error(s) detected
> 
> INFO: fallocate test...
> INFO: sz = 3e800000, npages = 256000
> INFO: vastart = 00007f2ad0bd0000
> INFO: thread 0 is 7f2ad0bcf700
> INFO: thread 1 is 7f2ad03ce700
> INFO: 0 error(s) detected
> 
> INFO: ftruncate test...
> INFO: sz = 3e800000, npages = 256000
> INFO: vastart = 00007f2ad0bd0000
> INFO: thread 0 is 7f2ad03ce700
> INFO: thread 1 is 7f2ad0bcf700
> ERROR: thread 0, offset 01001c00, 00000000 != 7f2ad03ce700
> ERROR: thread 0, offset 01801c00, 00000000 != 7f2ad03ce700
> ERROR: thread 0, offset 02001c00, 00000000 != 7f2ad03ce700
> ERROR: thread 0, offset 02807c00, 00000000 != 7f2ad03ce700
> ERROR: thread 0, offset 0281dc00, 00000000 != 7f2ad03ce700
> ERROR: thread 0, offset 03001c00, 00000000 != 7f2ad03ce700
> ERROR: thread 0, offset 03023c00, 00000000 != 7f2ad03ce700
> ERROR: thread 0, offset 03801c00, 00000000 != 7f2ad03ce700
> ERROR: thread 0, offset 03804c00, 00000000 != 7f2ad03ce700
> ERROR: thread 0, offset 04001c00, 00000000 != 7f2ad03ce700
> ERROR: thread 0, offset 04801c00, 00000000 != 7f2ad03ce700
> ERROR: thread 0, offset 05001c00, 00000000 != 7f2ad03ce700
> ERROR: thread 1, offset 0e001400, 00000000 != 7f2ad0bcf700
> ERROR: thread 1, offset 16001400, 00000000 != 7f2ad0bcf700
> ERROR: thread 1, offset 1b001400, 00000000 != 7f2ad0bcf700
> ERROR: thread 1, offset 2a802400, 00000000 != 7f2ad0bcf700
> ERROR: thread 1, offset 31005400, 00000000 != 7f2ad0bcf700
> ERROR: thread 0, offset 3e6b3c00, 00000000 != 7f2ad03ce700
> INFO: 18 error(s) detected
> $
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR
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