https://github.com/torvalds/linux
Revision 0d200aefd4ac51787b6b80de1bb7ce93bccd59f6 authored by Joe Thornber on 03 July 2012, 11:55:31 UTC, committed by Alasdair G Kergon on 03 July 2012, 11:55:31 UTC
Userland sometimes sees a corrupt metadata block if metadata is changing
rapidly when a metadata snapshot is reserved for userland,  To make the
problem go away, commit before we take the metadata snapshot (which is a
sensible thing to do anyway).

The checksums mean userland spots this corruption immediately so there's
no risk of acting on incorrect data.  No corruption exists from the
kernel's point of view, and thin_check passes after pool shutdown.

I believe this is to do with shared blocks at the first level of the
{device, mapping} btree.  Prior to the metadata-snap support no sharing
at this level was possible, so this patch is only required after commit
cc8394d86f045b86ff303d3c9e4ce47d97148951 ("dm thin: provide userspace
access to pool metadata").

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
1 parent 6887a41
Raw File
Tip revision: 0d200aefd4ac51787b6b80de1bb7ce93bccd59f6 authored by Joe Thornber on 03 July 2012, 11:55:31 UTC
dm thin: commit metadata before creating metadata snapshot
Tip revision: 0d200ae
minors.h
#ifndef __SOUND_MINORS_H
#define __SOUND_MINORS_H

/*
 *  MINOR numbers
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#define SNDRV_OS_MINORS			256

#define SNDRV_MINOR_DEVICES		32
#define SNDRV_MINOR_CARD(minor)		((minor) >> 5)
#define SNDRV_MINOR_DEVICE(minor)	((minor) & 0x001f)
#define SNDRV_MINOR(card, dev)		(((card) << 5) | (dev))

/* these minors can still be used for autoloading devices (/dev/aload*) */
#define SNDRV_MINOR_CONTROL		0	/* 0 */
#define SNDRV_MINOR_GLOBAL		1	/* 1 */
#define SNDRV_MINOR_SEQUENCER		1	/* SNDRV_MINOR_GLOBAL + 0 * 32 */
#define SNDRV_MINOR_TIMER		33	/* SNDRV_MINOR_GLOBAL + 1 * 32 */

#ifndef CONFIG_SND_DYNAMIC_MINORS
#define SNDRV_MINOR_COMPRESS		2	/* 2 - 3 */
#define SNDRV_MINOR_HWDEP		4	/* 4 - 7 */
#define SNDRV_MINOR_RAWMIDI		8	/* 8 - 15 */
#define SNDRV_MINOR_PCM_PLAYBACK	16	/* 16 - 23 */
#define SNDRV_MINOR_PCM_CAPTURE		24	/* 24 - 31 */

/* same as first respective minor number to make minor allocation easier */
#define SNDRV_DEVICE_TYPE_CONTROL	SNDRV_MINOR_CONTROL
#define SNDRV_DEVICE_TYPE_HWDEP		SNDRV_MINOR_HWDEP
#define SNDRV_DEVICE_TYPE_RAWMIDI	SNDRV_MINOR_RAWMIDI
#define SNDRV_DEVICE_TYPE_PCM_PLAYBACK	SNDRV_MINOR_PCM_PLAYBACK
#define SNDRV_DEVICE_TYPE_PCM_CAPTURE	SNDRV_MINOR_PCM_CAPTURE
#define SNDRV_DEVICE_TYPE_SEQUENCER	SNDRV_MINOR_SEQUENCER
#define SNDRV_DEVICE_TYPE_TIMER		SNDRV_MINOR_TIMER
#define SNDRV_DEVICE_TYPE_COMPRESS	SNDRV_MINOR_COMPRESS

#else /* CONFIG_SND_DYNAMIC_MINORS */

enum {
	SNDRV_DEVICE_TYPE_CONTROL,
	SNDRV_DEVICE_TYPE_SEQUENCER,
	SNDRV_DEVICE_TYPE_TIMER,
	SNDRV_DEVICE_TYPE_HWDEP,
	SNDRV_DEVICE_TYPE_RAWMIDI,
	SNDRV_DEVICE_TYPE_PCM_PLAYBACK,
	SNDRV_DEVICE_TYPE_PCM_CAPTURE,
	SNDRV_DEVICE_TYPE_COMPRESS,
};

#endif /* CONFIG_SND_DYNAMIC_MINORS */

#define SNDRV_MINOR_HWDEPS		4
#define SNDRV_MINOR_RAWMIDIS		8
#define SNDRV_MINOR_PCMS		8


#ifdef CONFIG_SND_OSSEMUL

#define SNDRV_MINOR_OSS_DEVICES		16
#define SNDRV_MINOR_OSS_CARD(minor)	((minor) >> 4)
#define SNDRV_MINOR_OSS_DEVICE(minor)	((minor) & 0x000f)
#define SNDRV_MINOR_OSS(card, dev)	(((card) << 4) | (dev))

#define SNDRV_MINOR_OSS_MIXER		0	/* /dev/mixer - OSS 3.XX compatible */
#define SNDRV_MINOR_OSS_SEQUENCER	1	/* /dev/sequencer - OSS 3.XX compatible */
#define	SNDRV_MINOR_OSS_MIDI		2	/* /dev/midi - native midi interface - OSS 3.XX compatible - UART */
#define SNDRV_MINOR_OSS_PCM		3	/* alias */
#define SNDRV_MINOR_OSS_PCM_8		3	/* /dev/dsp - 8bit PCM - OSS 3.XX compatible */
#define SNDRV_MINOR_OSS_AUDIO		4	/* /dev/audio - SunSparc compatible */
#define SNDRV_MINOR_OSS_PCM_16		5	/* /dev/dsp16 - 16bit PCM - OSS 3.XX compatible */
#define SNDRV_MINOR_OSS_SNDSTAT		6	/* /dev/sndstat - for compatibility with OSS */
#define SNDRV_MINOR_OSS_RESERVED7	7	/* reserved for future use */
#define SNDRV_MINOR_OSS_MUSIC		8	/* /dev/music - OSS 3.XX compatible */
#define SNDRV_MINOR_OSS_DMMIDI		9	/* /dev/dmmidi0 - this device can have another minor # with OSS */
#define SNDRV_MINOR_OSS_DMFM		10	/* /dev/dmfm0 - this device can have another minor # with OSS */
#define SNDRV_MINOR_OSS_MIXER1		11	/* alternate mixer */
#define SNDRV_MINOR_OSS_PCM1		12	/* alternate PCM (GF-A-1) */
#define SNDRV_MINOR_OSS_MIDI1		13	/* alternate midi - SYNTH */
#define SNDRV_MINOR_OSS_DMMIDI1		14	/* alternate dmmidi - SYNTH */
#define SNDRV_MINOR_OSS_RESERVED15	15	/* reserved for future use */

#define SNDRV_OSS_DEVICE_TYPE_MIXER	0
#define SNDRV_OSS_DEVICE_TYPE_SEQUENCER	1
#define SNDRV_OSS_DEVICE_TYPE_PCM	2
#define SNDRV_OSS_DEVICE_TYPE_MIDI	3
#define SNDRV_OSS_DEVICE_TYPE_DMFM	4
#define SNDRV_OSS_DEVICE_TYPE_SNDSTAT	5
#define SNDRV_OSS_DEVICE_TYPE_MUSIC	6

#define MODULE_ALIAS_SNDRV_MINOR(type) \
	MODULE_ALIAS("sound-service-?-" __stringify(type))

#endif

#endif /* __SOUND_MINORS_H */
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