/* * Copyright (C) 2001 Sistina Software (UK) Limited. * 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> struct dm_target; struct dm_table; struct dm_dev; struct mapped_device; typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t; union map_info { void *ptr; unsigned long long ll; }; /* * In the constructor the target parameter will already have the * table, type, begin and len fields filled in. */ typedef int (*dm_ctr_fn) (struct dm_target *target, unsigned int argc, char **argv); /* * The destructor doesn't need to free the dm_target, just * anything hidden ti->private. */ typedef void (*dm_dtr_fn) (struct dm_target *ti); /* * The map function must return: * < 0: error * = 0: The target will handle the io by resubmitting it later * = 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); /* * Returns: * < 0 : error (currently ignored) * 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 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, char *result, unsigned int maxlen); typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv); typedef int (*dm_ioctl_fn) (struct dm_target *ti, struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg); void dm_error(const char *message); /* * Combine device limits. */ void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev); /* * 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); void dm_put_device(struct dm_target *ti, struct dm_dev *d); /* * Information about a target type */ struct target_type { const char *name; struct module *module; unsigned version[3]; dm_ctr_fn ctr; dm_dtr_fn dtr; dm_map_fn map; dm_endio_fn 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; dm_ioctl_fn ioctl; }; struct io_restrictions { unsigned long bounce_pfn; unsigned long seg_boundary_mask; unsigned max_hw_sectors; unsigned max_sectors; unsigned max_segment_size; unsigned short hardsect_size; unsigned short max_hw_segments; unsigned short max_phys_segments; unsigned char no_cluster; /* inverted so that 0 is default */ }; struct dm_target { struct dm_table *table; struct target_type *type; /* target limits */ 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. */ struct io_restrictions limits; /* target specific data */ void *private; /* Used to provide an error string from the ctr */ char *error; }; int dm_register_target(struct target_type *t); int dm_unregister_target(struct target_type *t); /*----------------------------------------------------------------- * Functions for creating and manipulating mapped devices. * Drop the reference with dm_put when you finish with the object. *---------------------------------------------------------------*/ /* * DM_ANY_MINOR chooses the next available minor number. */ #define DM_ANY_MINOR (-1) int dm_create(int minor, struct mapped_device **md); /* * Reference counting for md. */ struct mapped_device *dm_get_md(dev_t dev); void dm_get(struct mapped_device *md); void dm_put(struct mapped_device *md); /* * An arbitrary pointer may be stored alongside a mapped device. */ void dm_set_mdptr(struct mapped_device *md, void *ptr); void *dm_get_mdptr(struct mapped_device *md); /* * A device can still be used while suspended, but I/O is deferred. */ int dm_suspend(struct mapped_device *md, unsigned suspend_flags); int dm_resume(struct mapped_device *md); /* * Event functions. */ 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); /* * Geometry functions. */ int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo); int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo); /*----------------------------------------------------------------- * Functions for manipulating device-mapper tables. *---------------------------------------------------------------*/ /* * First create an empty table. */ int dm_table_create(struct dm_table **result, int mode, unsigned num_targets, struct mapped_device *md); /* * Then call this once for each target. */ int dm_table_add_target(struct dm_table *t, const char *type, sector_t start, sector_t len, char *params); /* * Finally call this to make the table ready for use. */ int dm_table_complete(struct dm_table *t); /* * Table reference counting. */ struct dm_table *dm_get_table(struct mapped_device *md); void dm_table_get(struct dm_table *t); void dm_table_put(struct dm_table *t); /* * Queries */ 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); struct mapped_device *dm_table_get_md(struct dm_table *t); /* * Trigger an event. */ void dm_table_event(struct dm_table *t); /* * The device must be suspended before calling this method. */ 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(). */ int dm_create_error_table(struct dm_table **result, struct mapped_device *md); /*----------------------------------------------------------------- * Macros. *---------------------------------------------------------------*/ #define DM_NAME "device-mapper" #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 */ #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz)) 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); } #endif /* __KERNEL__ */ #endif /* _LINUX_DEVICE_MAPPER_H */ -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel