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
compress_offload.h
/*
 *  compress_offload.h - compress offload header definations
 *
 *  Copyright (C) 2011 Intel Corporation
 *  Authors:	Vinod Koul <vinod.koul@linux.intel.com>
 *		Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
 *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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; version 2 of the License.
 *
 *  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.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 */
#ifndef __COMPRESS_OFFLOAD_H
#define __COMPRESS_OFFLOAD_H

#include <linux/types.h>
#include <sound/asound.h>
#include <sound/compress_params.h>


#define SNDRV_COMPRESS_VERSION SNDRV_PROTOCOL_VERSION(0, 1, 0)
/**
 * struct snd_compressed_buffer: compressed buffer
 * @fragment_size: size of buffer fragment in bytes
 * @fragments: number of such fragments
 */
struct snd_compressed_buffer {
	__u32 fragment_size;
	__u32 fragments;
};

/**
 * struct snd_compr_params: compressed stream params
 * @buffer: buffer description
 * @codec: codec parameters
 * @no_wake_mode: dont wake on fragment elapsed
 */
struct snd_compr_params {
	struct snd_compressed_buffer buffer;
	struct snd_codec codec;
	__u8 no_wake_mode;
};

/**
 * struct snd_compr_tstamp: timestamp descriptor
 * @byte_offset: Byte offset in ring buffer to DSP
 * @copied_total: Total number of bytes copied from/to ring buffer to/by DSP
 * @pcm_frames: Frames decoded or encoded by DSP. This field will evolve by
 *	large steps and should only be used to monitor encoding/decoding
 *	progress. It shall not be used for timing estimates.
 * @pcm_io_frames: Frames rendered or received by DSP into a mixer or an audio
 * output/input. This field should be used for A/V sync or time estimates.
 * @sampling_rate: sampling rate of audio
 */
struct snd_compr_tstamp {
	__u32 byte_offset;
	__u32 copied_total;
	snd_pcm_uframes_t pcm_frames;
	snd_pcm_uframes_t pcm_io_frames;
	__u32 sampling_rate;
};

/**
 * struct snd_compr_avail: avail descriptor
 * @avail: Number of bytes available in ring buffer for writing/reading
 * @tstamp: timestamp infomation
 */
struct snd_compr_avail {
	__u64 avail;
	struct snd_compr_tstamp tstamp;
};

enum snd_compr_direction {
	SND_COMPRESS_PLAYBACK = 0,
	SND_COMPRESS_CAPTURE
};

/**
 * struct snd_compr_caps: caps descriptor
 * @codecs: pointer to array of codecs
 * @direction: direction supported. Of type snd_compr_direction
 * @min_fragment_size: minimum fragment supported by DSP
 * @max_fragment_size: maximum fragment supported by DSP
 * @min_fragments: min fragments supported by DSP
 * @max_fragments: max fragments supported by DSP
 * @num_codecs: number of codecs supported
 * @reserved: reserved field
 */
struct snd_compr_caps {
	__u32 num_codecs;
	__u32 direction;
	__u32 min_fragment_size;
	__u32 max_fragment_size;
	__u32 min_fragments;
	__u32 max_fragments;
	__u32 codecs[MAX_NUM_CODECS];
	__u32 reserved[11];
};

/**
 * struct snd_compr_codec_caps: query capability of codec
 * @codec: codec for which capability is queried
 * @num_descriptors: number of codec descriptors
 * @descriptor: array of codec capability descriptor
 */
struct snd_compr_codec_caps {
	__u32 codec;
	__u32 num_descriptors;
	struct snd_codec_desc descriptor[MAX_NUM_CODEC_DESCRIPTORS];
};

/**
 * compress path ioctl definitions
 * SNDRV_COMPRESS_GET_CAPS: Query capability of DSP
 * SNDRV_COMPRESS_GET_CODEC_CAPS: Query capability of a codec
 * SNDRV_COMPRESS_SET_PARAMS: Set codec and stream parameters
 * Note: only codec params can be changed runtime and stream params cant be
 * SNDRV_COMPRESS_GET_PARAMS: Query codec params
 * SNDRV_COMPRESS_TSTAMP: get the current timestamp value
 * SNDRV_COMPRESS_AVAIL: get the current buffer avail value.
 * This also queries the tstamp properties
 * SNDRV_COMPRESS_PAUSE: Pause the running stream
 * SNDRV_COMPRESS_RESUME: resume a paused stream
 * SNDRV_COMPRESS_START: Start a stream
 * SNDRV_COMPRESS_STOP: stop a running stream, discarding ring buffer content
 * and the buffers currently with DSP
 * SNDRV_COMPRESS_DRAIN: Play till end of buffers and stop after that
 * SNDRV_COMPRESS_IOCTL_VERSION: Query the API version
 */
#define SNDRV_COMPRESS_IOCTL_VERSION	_IOR('C', 0x00, int)
#define SNDRV_COMPRESS_GET_CAPS		_IOWR('C', 0x10, struct snd_compr_caps)
#define SNDRV_COMPRESS_GET_CODEC_CAPS	_IOWR('C', 0x11,\
						struct snd_compr_codec_caps)
#define SNDRV_COMPRESS_SET_PARAMS	_IOW('C', 0x12, struct snd_compr_params)
#define SNDRV_COMPRESS_GET_PARAMS	_IOR('C', 0x13, struct snd_codec)
#define SNDRV_COMPRESS_TSTAMP		_IOR('C', 0x20, struct snd_compr_tstamp)
#define SNDRV_COMPRESS_AVAIL		_IOR('C', 0x21, struct snd_compr_avail)
#define SNDRV_COMPRESS_PAUSE		_IO('C', 0x30)
#define SNDRV_COMPRESS_RESUME		_IO('C', 0x31)
#define SNDRV_COMPRESS_START		_IO('C', 0x32)
#define SNDRV_COMPRESS_STOP		_IO('C', 0x33)
#define SNDRV_COMPRESS_DRAIN		_IO('C', 0x34)
/*
 * TODO
 * 1. add mmap support
 *
 */
#define SND_COMPR_TRIGGER_DRAIN 7 /*FIXME move this to pcm.h */
#endif
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