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
Tip revision: 0d200aefd4ac51787b6b80de1bb7ce93bccd59f6 authored by Joe Thornber on 03 July 2012, 11:55:31 UTC
dm thin: commit metadata before creating metadata snapshot
dm thin: commit metadata before creating metadata snapshot
Tip revision: 0d200ae
hda_hwdep.h
/*
* HWDEP Interface for HD-audio codec
*
* Copyright (c) 2007 Takashi Iwai <tiwai@suse.de>
*
* This driver 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 driver 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 __SOUND_HDA_HWDEP_H
#define __SOUND_HDA_HWDEP_H
#define HDA_HWDEP_VERSION ((1 << 16) | (0 << 8) | (0 << 0)) /* 1.0.0 */
/* verb */
#define HDA_REG_NID_SHIFT 24
#define HDA_REG_VERB_SHIFT 8
#define HDA_REG_VAL_SHIFT 0
#define HDA_VERB(nid,verb,param) ((nid)<<24 | (verb)<<8 | (param))
struct hda_verb_ioctl {
u32 verb; /* HDA_VERB() */
u32 res; /* response */
};
/*
* ioctls
*/
#define HDA_IOCTL_PVERSION _IOR('H', 0x10, int)
#define HDA_IOCTL_VERB_WRITE _IOWR('H', 0x11, struct hda_verb_ioctl)
#define HDA_IOCTL_GET_WCAP _IOWR('H', 0x12, struct hda_verb_ioctl)
#endif
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