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23 October 2021, 00:29:24 UTC
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 
dm thin: commit metadata before creating metadata snapshot
 
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
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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
mixer_oss.h 
#ifndef __SOUND_MIXER_OSS_H
#define __SOUND_MIXER_OSS_H

/*
 *  OSS MIXER API
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 *
 *
 *   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
 *
 */

#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)

#define SNDRV_OSS_MAX_MIXERS	32

struct snd_mixer_oss_file;

struct snd_mixer_oss_slot {
	int number;
	unsigned int stereo: 1;
	int (*get_volume)(struct snd_mixer_oss_file *fmixer,
			  struct snd_mixer_oss_slot *chn,
			  int *left, int *right);
	int (*put_volume)(struct snd_mixer_oss_file *fmixer,
			  struct snd_mixer_oss_slot *chn,
			  int left, int right);
	int (*get_recsrc)(struct snd_mixer_oss_file *fmixer,
			  struct snd_mixer_oss_slot *chn,
			  int *active);
	int (*put_recsrc)(struct snd_mixer_oss_file *fmixer,
			  struct snd_mixer_oss_slot *chn,
			  int active);
	unsigned long private_value;
	void *private_data;
	void (*private_free)(struct snd_mixer_oss_slot *slot);
	int volume[2];
};

struct snd_mixer_oss {
	struct snd_card *card;
	char id[16];
	char name[32];
	struct snd_mixer_oss_slot slots[SNDRV_OSS_MAX_MIXERS]; /* OSS mixer slots */
	unsigned int mask_recsrc;		/* exclusive recsrc mask */
	int (*get_recsrc)(struct snd_mixer_oss_file *fmixer,
			  unsigned int *active_index);
	int (*put_recsrc)(struct snd_mixer_oss_file *fmixer,
			  unsigned int active_index);
	void *private_data_recsrc;
	void (*private_free_recsrc)(struct snd_mixer_oss *mixer);
	struct mutex reg_mutex;
	struct snd_info_entry *proc_entry;
	int oss_dev_alloc;
	/* --- */
	int oss_recsrc;
};

struct snd_mixer_oss_file {
	struct snd_card *card;
	struct snd_mixer_oss *mixer;
};

int snd_mixer_oss_ioctl_card(struct snd_card *card,
			     unsigned int cmd, unsigned long arg);

#endif /* CONFIG_SND_MIXER_OSS */

#endif /* __SOUND_MIXER_OSS_H */
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