45cbcd7983
Tighten the use of return values from the target map and end_io functions. Values of 2 and above are now explictly reserved for future use. There are no existing targets using such values. The patch has no effect on existing behaviour. o Reserve return values of 2 and above from target map functions. Any positive value currently indicates "mapping complete", but all existing drivers use the value 1. We now make that a requirement so we can assign new meaning to higher values in future. The new definition of return values from target map functions is: < 0 : error = 0 : The target will handle the io (DM_MAPIO_SUBMITTED). = 1 : Mapping completed (DM_MAPIO_REMAPPED). > 1 : Reserved (undefined). Previously this was the same as '= 1'. o Reserve return values of 2 and above from target end_io functions for similar reasons. DM_ENDIO_INCOMPLETE is introduced for a return value of 1. Test results: I have tested by using the multipath target. I/Os succeed when valid paths exist. I/Os are queued in the multipath target when there are no valid paths and queue_if_no_path is set. I/Os fail when there are no valid paths and queue_if_no_path is not set. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
152 lines
4.0 KiB
C
152 lines
4.0 KiB
C
/*
|
|
* Internal header file for device mapper
|
|
*
|
|
* Copyright (C) 2001, 2002 Sistina Software
|
|
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
|
|
*
|
|
* This file is released under the LGPL.
|
|
*/
|
|
|
|
#ifndef DM_INTERNAL_H
|
|
#define DM_INTERNAL_H
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/device-mapper.h>
|
|
#include <linux/list.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/hdreg.h>
|
|
|
|
#define DM_NAME "device-mapper"
|
|
|
|
#define DMERR(f, arg...) printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
|
|
#define DMWARN(f, arg...) printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
|
|
#define DMINFO(f, arg...) printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
|
|
#ifdef CONFIG_DM_DEBUG
|
|
# define DMDEBUG(f, arg...) printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg)
|
|
#else
|
|
# define DMDEBUG(f, arg...) do {} while (0)
|
|
#endif
|
|
|
|
#define DMEMIT(x...) sz += ((sz >= maxlen) ? \
|
|
0 : scnprintf(result + sz, maxlen - sz, x))
|
|
|
|
#define SECTOR_SHIFT 9
|
|
|
|
/*
|
|
* Definitions of return values from target end_io function.
|
|
*/
|
|
#define DM_ENDIO_INCOMPLETE 1
|
|
|
|
/*
|
|
* Definitions of return values from target map function.
|
|
*/
|
|
#define DM_MAPIO_SUBMITTED 0
|
|
#define DM_MAPIO_REMAPPED 1
|
|
|
|
/*
|
|
* Suspend feature flags
|
|
*/
|
|
#define DM_SUSPEND_LOCKFS_FLAG (1 << 0)
|
|
|
|
/*
|
|
* List of devices that a metadevice uses and should open/close.
|
|
*/
|
|
struct dm_dev {
|
|
struct list_head list;
|
|
|
|
atomic_t count;
|
|
int mode;
|
|
struct block_device *bdev;
|
|
char name[16];
|
|
};
|
|
|
|
struct dm_table;
|
|
|
|
/*-----------------------------------------------------------------
|
|
* Internal table functions.
|
|
*---------------------------------------------------------------*/
|
|
void dm_table_event_callback(struct dm_table *t,
|
|
void (*fn)(void *), void *context);
|
|
struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
|
|
struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
|
|
void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q);
|
|
struct list_head *dm_table_get_devices(struct dm_table *t);
|
|
void dm_table_presuspend_targets(struct dm_table *t);
|
|
void dm_table_postsuspend_targets(struct dm_table *t);
|
|
int dm_table_resume_targets(struct dm_table *t);
|
|
int dm_table_any_congested(struct dm_table *t, int bdi_bits);
|
|
void dm_table_unplug_all(struct dm_table *t);
|
|
int dm_table_flush_all(struct dm_table *t);
|
|
|
|
/*-----------------------------------------------------------------
|
|
* A registry of target types.
|
|
*---------------------------------------------------------------*/
|
|
int dm_target_init(void);
|
|
void dm_target_exit(void);
|
|
struct target_type *dm_get_target_type(const char *name);
|
|
void dm_put_target_type(struct target_type *t);
|
|
int dm_target_iterate(void (*iter_func)(struct target_type *tt,
|
|
void *param), void *param);
|
|
|
|
/*-----------------------------------------------------------------
|
|
* Useful inlines.
|
|
*---------------------------------------------------------------*/
|
|
static inline int array_too_big(unsigned long fixed, unsigned long obj,
|
|
unsigned long num)
|
|
{
|
|
return (num > (ULONG_MAX - fixed) / obj);
|
|
}
|
|
|
|
/*
|
|
* Ceiling(n / sz)
|
|
*/
|
|
#define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
|
|
|
|
#define dm_sector_div_up(n, sz) ( \
|
|
{ \
|
|
sector_t _r = ((n) + (sz) - 1); \
|
|
sector_div(_r, (sz)); \
|
|
_r; \
|
|
} \
|
|
)
|
|
|
|
/*
|
|
* ceiling(n / size) * size
|
|
*/
|
|
#define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
|
|
|
|
static inline sector_t to_sector(unsigned long n)
|
|
{
|
|
return (n >> 9);
|
|
}
|
|
|
|
static inline unsigned long to_bytes(sector_t n)
|
|
{
|
|
return (n << 9);
|
|
}
|
|
|
|
int dm_split_args(int *argc, char ***argvp, char *input);
|
|
|
|
/*
|
|
* The device-mapper can be driven through one of two interfaces;
|
|
* ioctl or filesystem, depending which patch you have applied.
|
|
*/
|
|
int dm_interface_init(void);
|
|
void dm_interface_exit(void);
|
|
|
|
/*
|
|
* Targets for linear and striped mappings
|
|
*/
|
|
int dm_linear_init(void);
|
|
void dm_linear_exit(void);
|
|
|
|
int dm_stripe_init(void);
|
|
void dm_stripe_exit(void);
|
|
|
|
void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
|
|
union map_info *dm_get_mapinfo(struct bio *bio);
|
|
int dm_open_count(struct mapped_device *md);
|
|
int dm_lock_for_deletion(struct mapped_device *md);
|
|
|
|
#endif
|