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Revision 3e1a0699095803e53072699a4a1485af7744601d authored by Joe Thornber on 03 March 2014, 16:03:26 UTC, committed by Mike Snitzer on 05 March 2014, 20:26:58 UTC 
dm thin: fix out of data space handling
 
Ideally a thin pool would never run out of data space; the low water
mark would trigger userland to extend the pool before we completely run
out of space.  However, many small random IOs to unprovisioned space can
consume data space at an alarming rate.  Adjust your low water mark if
you're frequently seeing "out-of-data-space" mode.

Before this fix, if data space ran out the pool would be put in
PM_READ_ONLY mode which also aborted the pool's current metadata
transaction (data loss for any changes in the transaction).  This had a
side-effect of needlessly compromising data consistency.  And retry of
queued unserviceable bios, once the data pool was resized, could
initiate changes to potentially inconsistent pool metadata.

Now when the pool's data space is exhausted transition to a new pool
mode (PM_OUT_OF_DATA_SPACE) that allows metadata to be changed but data
may not be allocated.  This allows users to remove thin volumes or
discard data to recover data space.

The pool is no longer put in PM_READ_ONLY mode in response to the pool
running out of data space.  And PM_READ_ONLY mode no longer aborts the
pool's current metadata transaction.  Also, set_pool_mode() will now
notify userspace when the pool mode is changed.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
1 parent 07f2b6e
Raw File
g_NCR5380.h 
/*
 * Generic Generic NCR5380 driver defines
 *
 * Copyright 1993, Drew Eckhardt
 *	Visionary Computing
 *	(Unix and Linux consulting and custom programming)
 *	drew@colorado.edu
 *      +1 (303) 440-4894
 *
 * NCR53C400 extensions (c) 1994,1995,1996, Kevin Lentin
 *    K.Lentin@cs.monash.edu.au
 *
 * ALPHA RELEASE 1. 
 *
 * For more information, please consult 
 *
 * NCR 5380 Family
 * SCSI Protocol Controller
 * Databook
 *
 * NCR Microelectronics
 * 1635 Aeroplaza Drive
 * Colorado Springs, CO 80916
 * 1+ (719) 578-3400
 * 1+ (800) 334-5454
 */

/*
 * $Log: generic_NCR5380.h,v $
 */

#ifndef GENERIC_NCR5380_H
#define GENERIC_NCR5380_H


#define GENERIC_NCR5380_PUBLIC_RELEASE 1

#ifdef NCR53C400
#define BIOSPARAM
#define NCR5380_BIOSPARAM generic_NCR5380_biosparam
#else
#define NCR5380_BIOSPARAM NULL
#endif

#ifndef ASM
static int generic_NCR5380_abort(Scsi_Cmnd *);
static int generic_NCR5380_detect(struct scsi_host_template *);
static int generic_NCR5380_release_resources(struct Scsi_Host *);
static int generic_NCR5380_queue_command(struct Scsi_Host *, struct scsi_cmnd *);
static int generic_NCR5380_bus_reset(Scsi_Cmnd *);
static const char* generic_NCR5380_info(struct Scsi_Host *);

#ifndef CMD_PER_LUN
#define CMD_PER_LUN 2
#endif

#ifndef CAN_QUEUE
#define CAN_QUEUE 16
#endif

#ifndef HOSTS_C

#define __STRVAL(x) #x
#define STRVAL(x) __STRVAL(x)

#ifndef SCSI_G_NCR5380_MEM

#define NCR5380_map_config port
#define NCR5380_map_type int
#define NCR5380_map_name port
#define NCR5380_instance_name io_port
#define NCR53C400_register_offset 0
#define NCR53C400_address_adjust 8

#ifdef NCR53C400
#define NCR5380_region_size 16
#else
#define NCR5380_region_size 8
#endif

#define NCR5380_read(reg) (inb(NCR5380_map_name + (reg)))
#define NCR5380_write(reg, value) (outb((value), (NCR5380_map_name + (reg))))

#define NCR5380_implementation_fields \
    NCR5380_map_type NCR5380_map_name

#define NCR5380_local_declare() \
    register NCR5380_implementation_fields

#define NCR5380_setup(instance) \
    NCR5380_map_name = (NCR5380_map_type)((instance)->NCR5380_instance_name)

#else 
/* therefore SCSI_G_NCR5380_MEM */

#define NCR5380_map_config memory
#define NCR5380_map_type unsigned long
#define NCR5380_map_name base
#define NCR5380_instance_name base
#define NCR53C400_register_offset 0x108
#define NCR53C400_address_adjust 0
#define NCR53C400_mem_base 0x3880
#define NCR53C400_host_buffer 0x3900
#define NCR5380_region_size 0x3a00

#define NCR5380_read(reg) readb(iomem + NCR53C400_mem_base + (reg))
#define NCR5380_write(reg, value) writeb(value, iomem + NCR53C400_mem_base + (reg))

#define NCR5380_implementation_fields \
    NCR5380_map_type NCR5380_map_name; \
    void __iomem *iomem;

#define NCR5380_local_declare() \
    register void __iomem *iomem

#define NCR5380_setup(instance) \
    iomem = (((struct NCR5380_hostdata *)(instance)->hostdata)->iomem)

#endif

#define NCR5380_intr generic_NCR5380_intr
#define NCR5380_queue_command generic_NCR5380_queue_command
#define NCR5380_abort generic_NCR5380_abort
#define NCR5380_bus_reset generic_NCR5380_bus_reset
#define NCR5380_pread generic_NCR5380_pread
#define NCR5380_pwrite generic_NCR5380_pwrite
#define NCR5380_proc_info notyet_generic_proc_info

#define BOARD_NCR5380	0
#define BOARD_NCR53C400	1
#define BOARD_NCR53C400A 2
#define BOARD_DTC3181E	3

#endif /* else def HOSTS_C */
#endif /* ndef ASM */
#endif /* GENERIC_NCR5380_H */
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