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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
wm2200.h 
/*
 * linux/sound/wm2200.h -- Platform data for WM2200
 *
 * Copyright 2012 Wolfson Microelectronics. PLC.
 *
 * 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_WM2200_H
#define __LINUX_SND_WM2200_H

#define WM2200_GPIO_SET 0x10000

enum wm2200_in_mode {
	WM2200_IN_SE = 0,
	WM2200_IN_DIFF = 1,
	WM2200_IN_DMIC = 2,
};

enum wm2200_dmic_sup {
	WM2200_DMIC_SUP_MICVDD = 0,
	WM2200_DMIC_SUP_MICBIAS1 = 1,
	WM2200_DMIC_SUP_MICBIAS2 = 2,
};

struct wm2200_pdata {
	int reset;      /** GPIO controlling /RESET, if any */
	int ldo_ena;    /** GPIO controlling LODENA, if any */
	int irq_flags;

	int gpio_defaults[4];

	enum wm2200_in_mode in_mode[3];
	enum wm2200_dmic_sup dmic_sup[3];

	int micbias_cfg[2];  /** Register value to configure MICBIAS */
};

#endif
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