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
cs46xx_dsp_task_types.h
/*
 *  The driver for the Cirrus Logic's Sound Fusion CS46XX based soundcards
 *  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
 *
 *
 * NOTE: comments are copy/paste from cwcemb80.lst 
 * provided by Tom Woller at Cirrus (my only
 * documentation about the SP OS running inside
 * the DSP) 
 */

#ifndef __CS46XX_DSP_TASK_TYPES_H__
#define __CS46XX_DSP_TASK_TYPES_H__

#include "cs46xx_dsp_scb_types.h"

/*********************************************************************************************
Example hierarchy of stream control blocks in the SP

hfgTree
Ptr____Call (c)
       \
 -------+------         -------------      -------------      -------------      -----
| SBlaster IF  |______\| Foreground  |___\| Middlegr'nd |___\| Background  |___\| Nul |
|              |Goto  /| tree header |g  /| tree header |g  /| tree header |g  /| SCB |r
 -------------- (g)     -------------      -------------      -------------      -----
       |c                     |c                 |c                 |c
       |                      |                  |                  |
      \/                  -------------      -------------      -------------   
                       | Foreground  |_\  | Middlegr'nd |_\  | Background  |_\
                       |     tree    |g/  |    tree     |g/  |     tree    |g/
                        -------------      -------------      -------------   
                              |c                 |c                 |c
                              |                  |                  | 
                             \/                 \/                 \/ 

*********************************************************************************************/

#define		HFG_FIRST_EXECUTE_MODE			0x0001
#define		HFG_FIRST_EXECUTE_MODE_BIT		0
#define		HFG_CONTEXT_SWITCH_MODE			0x0002
#define		HFG_CONTEXT_SWITCH_MODE_BIT		1

#define MAX_FG_STACK_SIZE 	32			/* THESE NEED TO BE COMPUTED PROPERLY */
#define MAX_MG_STACK_SIZE 	16
#define MAX_BG_STACK_SIZE 	9
#define MAX_HFG_STACK_SIZE	4

#define SLEEP_ACTIVE_INCREMENT		0		/* Enable task tree thread to go to sleep
											   This should only ever be used on the Background thread */
#define STANDARD_ACTIVE_INCREMENT	1		/* Task tree thread normal operation */
#define SUSPEND_ACTIVE_INCREMENT	2		/* Cause execution to suspend in the task tree thread
                                               This should only ever be used on the Background thread */

#define HOSTFLAGS_DISABLE_BG_SLEEP  0       /* Host-controlled flag that determines whether we go to sleep
                                               at the end of BG */

/* Minimal context save area for Hyper Forground */
struct dsp_hf_save_area {
	u32	r10_save;
	u32	r54_save;
	u32	r98_save;

	___DSP_DUAL_16BIT_ALLOC(
	    status_save,
	    ind_save
	)

	___DSP_DUAL_16BIT_ALLOC(
	    rci1_save,
	    rci0_save
	)

	u32	r32_save;
	u32	r76_save;
	u32	rsd2_save;

       	___DSP_DUAL_16BIT_ALLOC(
	      rsi2_save,	  /* See TaskTreeParameterBlock for 
				     remainder of registers  */
	      rsa2Save
	)
	/* saved as part of HFG context  */
};


/* Task link data structure */
struct dsp_tree_link {
	___DSP_DUAL_16BIT_ALLOC(
	/* Pointer to sibling task control block */
	    next_scb,
	/* Pointer to child task control block */
	    sub_ptr
	)
  
	___DSP_DUAL_16BIT_ALLOC(
	/* Pointer to code entry point */
	    entry_point, 
	/* Pointer to local data */
	    this_spb
	)
};


struct dsp_task_tree_data {
	___DSP_DUAL_16BIT_ALLOC(
	/* Initial tock count; controls task tree execution rate */
	    tock_count_limit,
	/* Tock down counter */
	    tock_count
	)

	/* Add to ActiveCount when TockCountLimit reached: 
	   Subtract on task tree termination */
	___DSP_DUAL_16BIT_ALLOC(
	    active_tncrement,		
	/* Number of pending activations for task tree */
	    active_count
	)

        ___DSP_DUAL_16BIT_ALLOC(
	/* BitNumber to enable modification of correct bit in ActiveTaskFlags */
	    active_bit,	    
	/* Pointer to OS location for indicating current activity on task level */
	    active_task_flags_ptr
	)

	/* Data structure for controlling movement of memory blocks:- 
	   currently unused */
	___DSP_DUAL_16BIT_ALLOC(
	    mem_upd_ptr,
	/* Data structure for controlling synchronous link update */
	    link_upd_ptr
	)
  
	___DSP_DUAL_16BIT_ALLOC(
	/* Save area for remainder of full context. */
	    save_area,
	/* Address of start of local stack for data storage */
	    data_stack_base_ptr
	)

};


struct dsp_interval_timer_data
{
	/* These data items have the same relative locations to those */
	___DSP_DUAL_16BIT_ALLOC(
	     interval_timer_period,
	     itd_unused
	)

	/* used for this data in the SPOS control block for SPOS 1.0 */
	___DSP_DUAL_16BIT_ALLOC(
	     num_FG_ticks_this_interval,        
	     num_intervals
	)
};


/* This structure contains extra storage for the task tree
   Currently, this additional data is related only to a full context save */
struct dsp_task_tree_context_block {
	/* Up to 10 values are saved onto the stack.  8 for the task tree, 1 for
	   The access to the context switch (call or interrupt), and 1 spare that
	   users should never use.  This last may be required by the system */
	___DSP_DUAL_16BIT_ALLOC(
	     stack1,
	     stack0
	)
	___DSP_DUAL_16BIT_ALLOC(
	     stack3,
	     stack2
	)
	___DSP_DUAL_16BIT_ALLOC(
	     stack5,
	     stack4
	)
	___DSP_DUAL_16BIT_ALLOC(
	     stack7,
	     stack6
	)
	___DSP_DUAL_16BIT_ALLOC(
	     stack9,
	     stack8
	)

	u32	  saverfe;					

	/* Value may be overwriten by stack save algorithm.
	   Retain the size of the stack data saved here if used */
	___DSP_DUAL_16BIT_ALLOC(
             reserved1,	
  	     stack_size
	)
	u32		saverba;	  /* (HFG) */
	u32		saverdc;
	u32		savers_config_23; /* (HFG) */
	u32		savers_DMA23;	  /* (HFG) */
	u32		saversa0;
	u32		saversi0;
	u32		saversa1;
	u32		saversi1;
	u32		saversa3;
	u32		saversd0;
	u32		saversd1;
	u32		saversd3;
	u32		savers_config01;
	u32		savers_DMA01;
	u32		saveacc0hl;
	u32		saveacc1hl;
	u32		saveacc0xacc1x;
	u32		saveacc2hl;
	u32		saveacc3hl;
	u32		saveacc2xacc3x;
	u32		saveaux0hl;
	u32		saveaux1hl;
	u32		saveaux0xaux1x;
	u32		saveaux2hl;
	u32		saveaux3hl;
	u32		saveaux2xaux3x;
	u32		savershouthl;
	u32		savershoutxmacmode;
};
                

struct dsp_task_tree_control_block {
	struct dsp_hf_save_area			context;
	struct dsp_tree_link			links;
	struct dsp_task_tree_data		data;
	struct dsp_task_tree_context_block	context_blk;
	struct dsp_interval_timer_data		int_timer;
};


#endif /* __DSP_TASK_TYPES_H__ */
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