/*
* Copyright (C) 2001 Sistina Software (UK) Limited.
- * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
*
* This file is released under the LGPL.
*/
#ifndef _LINUX_DEVICE_MAPPER_H
#define _LINUX_DEVICE_MAPPER_H
-#ifdef __KERNEL__
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+struct dm_dev;
struct dm_target;
struct dm_table;
-struct dm_dev;
struct mapped_device;
+struct bio_vec;
typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
union map_info {
void *ptr;
unsigned long long ll;
+ unsigned flush_request;
};
/*
* The map function must return:
* < 0: error
* = 0: The target will handle the io by resubmitting it later
- * > 0: simple remap complete
+ * = 1: simple remap complete
+ * = 2: The target wants to push back the io
*/
typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio,
union map_info *map_context);
+typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone,
+ union map_info *map_context);
/*
* Returns:
* 0 : ended successfully
* 1 : for some reason the io has still not completed (eg,
* multipath target might want to requeue a failed io).
+ * 2 : The target wants to push back the io
*/
typedef int (*dm_endio_fn) (struct dm_target *ti,
struct bio *bio, int error,
union map_info *map_context);
+typedef int (*dm_request_endio_fn) (struct dm_target *ti,
+ struct request *clone, int error,
+ union map_info *map_context);
+typedef void (*dm_flush_fn) (struct dm_target *ti);
typedef void (*dm_presuspend_fn) (struct dm_target *ti);
typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
+typedef int (*dm_preresume_fn) (struct dm_target *ti);
typedef void (*dm_resume_fn) (struct dm_target *ti);
typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv);
+typedef int (*dm_ioctl_fn) (struct dm_target *ti, unsigned int cmd,
+ unsigned long arg);
+
+typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm,
+ struct bio_vec *biovec, int max_size);
+
+typedef int (*iterate_devices_callout_fn) (struct dm_target *ti,
+ struct dm_dev *dev,
+ sector_t start, sector_t len,
+ void *data);
+
+typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
+ iterate_devices_callout_fn fn,
+ void *data);
+
+typedef void (*dm_io_hints_fn) (struct dm_target *ti,
+ struct queue_limits *limits);
+
+/*
+ * Returns:
+ * 0: The target can handle the next I/O immediately.
+ * 1: The target can't handle the next I/O immediately.
+ */
+typedef int (*dm_busy_fn) (struct dm_target *ti);
+
void dm_error(const char *message);
/*
+ * Combine device limits.
+ */
+int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
+ sector_t start, sector_t len, void *data);
+
+struct dm_dev {
+ struct block_device *bdev;
+ fmode_t mode;
+ char name[16];
+};
+
+/*
* Constructors should call these functions to ensure destination devices
* are opened/closed correctly.
* FIXME: too many arguments.
*/
int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
- sector_t len, int mode, struct dm_dev **result);
+ sector_t len, fmode_t mode, struct dm_dev **result);
void dm_put_device(struct dm_target *ti, struct dm_dev *d);
/*
* Information about a target type
*/
+
+/*
+ * Target features
+ */
+
struct target_type {
+ uint64_t features;
const char *name;
struct module *module;
unsigned version[3];
dm_ctr_fn ctr;
dm_dtr_fn dtr;
dm_map_fn map;
+ dm_map_request_fn map_rq;
dm_endio_fn end_io;
+ dm_request_endio_fn rq_end_io;
+ dm_flush_fn flush;
dm_presuspend_fn presuspend;
dm_postsuspend_fn postsuspend;
+ dm_preresume_fn preresume;
dm_resume_fn resume;
dm_status_fn status;
dm_message_fn message;
-};
-
-struct io_restrictions {
- unsigned int max_sectors;
- unsigned short max_phys_segments;
- unsigned short max_hw_segments;
- unsigned short hardsect_size;
- unsigned int max_segment_size;
- unsigned long seg_boundary_mask;
- unsigned char no_cluster; /* inverted so that 0 is default */
+ dm_ioctl_fn ioctl;
+ dm_merge_fn merge;
+ dm_busy_fn busy;
+ dm_iterate_devices_fn iterate_devices;
+ dm_io_hints_fn io_hints;
+
+ /* For internal device-mapper use. */
+ struct list_head list;
};
struct dm_target {
sector_t begin;
sector_t len;
- /* FIXME: turn this into a mask, and merge with io_restrictions */
/* Always a power of 2 */
sector_t split_io;
/*
- * These are automatically filled in by
- * dm_table_get_device.
+ * A number of zero-length barrier requests that will be submitted
+ * to the target for the purpose of flushing cache.
+ *
+ * The request number will be placed in union map_info->flush_request.
+ * It is a responsibility of the target driver to remap these requests
+ * to the real underlying devices.
*/
- struct io_restrictions limits;
+ unsigned num_flush_requests;
/* target specific data */
void *private;
};
int dm_register_target(struct target_type *t);
-int dm_unregister_target(struct target_type *t);
-
+void dm_unregister_target(struct target_type *t);
/*-----------------------------------------------------------------
* Functions for creating and manipulating mapped devices.
/*
* A device can still be used while suspended, but I/O is deferred.
*/
-int dm_suspend(struct mapped_device *md, int with_lockfs);
+int dm_suspend(struct mapped_device *md, unsigned suspend_flags);
int dm_resume(struct mapped_device *md);
/*
*/
uint32_t dm_get_event_nr(struct mapped_device *md);
int dm_wait_event(struct mapped_device *md, int event_nr);
+uint32_t dm_next_uevent_seq(struct mapped_device *md);
+void dm_uevent_add(struct mapped_device *md, struct list_head *elist);
/*
* Info functions.
*/
const char *dm_device_name(struct mapped_device *md);
+int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
struct gendisk *dm_disk(struct mapped_device *md);
int dm_suspended(struct mapped_device *md);
+int dm_noflush_suspending(struct dm_target *ti);
+union map_info *dm_get_mapinfo(struct bio *bio);
+union map_info *dm_get_rq_mapinfo(struct request *rq);
/*
* Geometry functions.
/*
* First create an empty table.
*/
-int dm_table_create(struct dm_table **result, int mode,
+int dm_table_create(struct dm_table **result, fmode_t mode,
unsigned num_targets, struct mapped_device *md);
/*
int dm_table_complete(struct dm_table *t);
/*
+ * Unplug all devices in a table.
+ */
+void dm_table_unplug_all(struct dm_table *t);
+
+/*
* Table reference counting.
*/
struct dm_table *dm_get_table(struct mapped_device *md);
*/
sector_t dm_table_get_size(struct dm_table *t);
unsigned int dm_table_get_num_targets(struct dm_table *t);
-int dm_table_get_mode(struct dm_table *t);
+fmode_t dm_table_get_mode(struct dm_table *t);
struct mapped_device *dm_table_get_md(struct dm_table *t);
/*
int dm_swap_table(struct mapped_device *md, struct dm_table *t);
/*
- * Prepare a table for a device that will error all I/O.
- * To make it active, call dm_suspend(), dm_swap_table() then dm_resume().
+ * A wrapper around vmalloc.
+ */
+void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
+
+/*-----------------------------------------------------------------
+ * Macros.
+ *---------------------------------------------------------------*/
+#define DM_NAME "device-mapper"
+
+#define DMCRIT(f, arg...) \
+ printk(KERN_CRIT DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
+
+#define DMERR(f, arg...) \
+ printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
+#define DMERR_LIMIT(f, arg...) \
+ do { \
+ if (printk_ratelimit()) \
+ printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " \
+ f "\n", ## arg); \
+ } while (0)
+
+#define DMWARN(f, arg...) \
+ printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
+#define DMWARN_LIMIT(f, arg...) \
+ do { \
+ if (printk_ratelimit()) \
+ printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " \
+ f "\n", ## arg); \
+ } while (0)
+
+#define DMINFO(f, arg...) \
+ printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
+#define DMINFO_LIMIT(f, arg...) \
+ do { \
+ if (printk_ratelimit()) \
+ printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f \
+ "\n", ## arg); \
+ } while (0)
+
+#ifdef CONFIG_DM_DEBUG
+# define DMDEBUG(f, arg...) \
+ printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX " DEBUG: " f "\n", ## arg)
+# define DMDEBUG_LIMIT(f, arg...) \
+ do { \
+ if (printk_ratelimit()) \
+ printk(KERN_DEBUG DM_NAME ": " DM_MSG_PREFIX ": " f \
+ "\n", ## arg); \
+ } while (0)
+#else
+# define DMDEBUG(f, arg...) do {} while (0)
+# define DMDEBUG_LIMIT(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
+#define DM_ENDIO_REQUEUE 2
+
+/*
+ * Definitions of return values from target map function.
+ */
+#define DM_MAPIO_SUBMITTED 0
+#define DM_MAPIO_REMAPPED 1
+#define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
+
+/*
+ * 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
*/
-int dm_create_error_table(struct dm_table **result, struct mapped_device *md);
+#define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
+
+#define dm_array_too_big(fixed, obj, num) \
+ ((num) > (UINT_MAX - (fixed)) / (obj))
+
+static inline sector_t to_sector(unsigned long n)
+{
+ return (n >> SECTOR_SHIFT);
+}
+
+static inline unsigned long to_bytes(sector_t n)
+{
+ return (n << SECTOR_SHIFT);
+}
+
+/*-----------------------------------------------------------------
+ * Helper for block layer and dm core operations
+ *---------------------------------------------------------------*/
+void dm_dispatch_request(struct request *rq);
+void dm_requeue_unmapped_request(struct request *rq);
+void dm_kill_unmapped_request(struct request *rq, int error);
+int dm_underlying_device_busy(struct request_queue *q);
-#endif /* __KERNEL__ */
#endif /* _LINUX_DEVICE_MAPPER_H */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff