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
soc-dpcm.h
/*
 * linux/sound/soc-dpcm.h -- ALSA SoC Dynamic PCM Support
 *
 * Author:		Liam Girdwood <lrg@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#ifndef __LINUX_SND_SOC_DPCM_H
#define __LINUX_SND_SOC_DPCM_H

#include <linux/list.h>
#include <sound/pcm.h>

struct snd_soc_pcm_runtime;

/*
 * Types of runtime_update to perform. e.g. originated from FE PCM ops
 * or audio route changes triggered by muxes/mixers.
 */
enum snd_soc_dpcm_update {
	SND_SOC_DPCM_UPDATE_NO	= 0,
	SND_SOC_DPCM_UPDATE_BE,
	SND_SOC_DPCM_UPDATE_FE,
};

/*
 * Dynamic PCM Frontend -> Backend link management states.
 */
enum snd_soc_dpcm_link_state {
	SND_SOC_DPCM_LINK_STATE_NEW	= 0,	/* newly created link */
	SND_SOC_DPCM_LINK_STATE_FREE,		/* link to be dismantled */
};

/*
 * Dynamic PCM Frontend -> Backend link PCM states.
 */
enum snd_soc_dpcm_state {
	SND_SOC_DPCM_STATE_NEW	= 0,
	SND_SOC_DPCM_STATE_OPEN,
	SND_SOC_DPCM_STATE_HW_PARAMS,
	SND_SOC_DPCM_STATE_PREPARE,
	SND_SOC_DPCM_STATE_START,
	SND_SOC_DPCM_STATE_STOP,
	SND_SOC_DPCM_STATE_PAUSED,
	SND_SOC_DPCM_STATE_SUSPEND,
	SND_SOC_DPCM_STATE_HW_FREE,
	SND_SOC_DPCM_STATE_CLOSE,
};

/*
 * Dynamic PCM trigger ordering. Triggering flexibility is required as some
 * DSPs require triggering before/after their CPU platform and DAIs.
 *
 * i.e. some clients may want to manually order this call in their PCM
 * trigger() whilst others will just use the regular core ordering.
 */
enum snd_soc_dpcm_trigger {
	SND_SOC_DPCM_TRIGGER_PRE		= 0,
	SND_SOC_DPCM_TRIGGER_POST,
	SND_SOC_DPCM_TRIGGER_BESPOKE,
};

/*
 * Dynamic PCM link
 * This links together a FE and BE DAI at runtime and stores the link
 * state information and the hw_params configuration.
 */
struct snd_soc_dpcm {
	/* FE and BE DAIs*/
	struct snd_soc_pcm_runtime *be;
	struct snd_soc_pcm_runtime *fe;

	/* link state */
	enum snd_soc_dpcm_link_state state;

	/* list of BE and FE for this DPCM link */
	struct list_head list_be;
	struct list_head list_fe;

	/* hw params for this link - may be different for each link */
	struct snd_pcm_hw_params hw_params;
#ifdef CONFIG_DEBUG_FS
	struct dentry *debugfs_state;
#endif
};

/*
 * Dynamic PCM runtime data.
 */
struct snd_soc_dpcm_runtime {
	struct list_head be_clients;
	struct list_head fe_clients;

	int users;
	struct snd_pcm_runtime *runtime;
	struct snd_pcm_hw_params hw_params;

	/* state and update */
	enum snd_soc_dpcm_update runtime_update;
	enum snd_soc_dpcm_state state;
};

/* can this BE stop and free */
int snd_soc_dpcm_can_be_free_stop(struct snd_soc_pcm_runtime *fe,
		struct snd_soc_pcm_runtime *be, int stream);

/* can this BE perform a hw_params() */
int snd_soc_dpcm_can_be_params(struct snd_soc_pcm_runtime *fe,
		struct snd_soc_pcm_runtime *be, int stream);

/* is the current PCM operation for this FE ? */
int snd_soc_dpcm_fe_can_update(struct snd_soc_pcm_runtime *fe, int stream);

/* is the current PCM operation for this BE ? */
int snd_soc_dpcm_be_can_update(struct snd_soc_pcm_runtime *fe,
		struct snd_soc_pcm_runtime *be, int stream);

/* get the substream for this BE */
struct snd_pcm_substream *
	snd_soc_dpcm_get_substream(struct snd_soc_pcm_runtime *be, int stream);

/* get the BE runtime state */
enum snd_soc_dpcm_state
	snd_soc_dpcm_be_get_state(struct snd_soc_pcm_runtime *be, int stream);

/* set the BE runtime state */
void snd_soc_dpcm_be_set_state(struct snd_soc_pcm_runtime *be, int stream,
	enum snd_soc_dpcm_state state);

/* internal use only */
int soc_dpcm_be_digital_mute(struct snd_soc_pcm_runtime *fe, int mute);
int soc_dpcm_debugfs_add(struct snd_soc_pcm_runtime *rtd);
int soc_dpcm_runtime_update(struct snd_soc_dapm_widget *);

#endif
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