diff options
Diffstat (limited to 'include/linux/device-mapper.h')
| -rw-r--r-- | include/linux/device-mapper.h | 158 |
1 files changed, 125 insertions, 33 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 98f34b886f9..e1707de043a 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -10,6 +10,7 @@ #include <linux/bio.h> #include <linux/blkdev.h> +#include <linux/math64.h> #include <linux/ratelimit.h> struct dm_dev; @@ -22,8 +23,6 @@ typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t; union map_info { void *ptr; - unsigned long long ll; - unsigned target_request_nr; }; /* @@ -46,8 +45,7 @@ typedef void (*dm_dtr_fn) (struct dm_target *ti); * = 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_fn) (struct dm_target *ti, struct bio *bio); typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone, union map_info *map_context); @@ -60,20 +58,18 @@ typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone, * 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); + struct bio *bio, int error); 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, - char *result, unsigned int maxlen); +typedef void (*dm_status_fn) (struct dm_target *ti, status_type_t status_type, + unsigned status_flags, char *result, unsigned maxlen); typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv); @@ -83,11 +79,26 @@ typedef int (*dm_ioctl_fn) (struct dm_target *ti, unsigned int cmd, typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm, struct bio_vec *biovec, int max_size); +/* + * These iteration functions are typically used to check (and combine) + * properties of underlying devices. + * E.g. Does at least one underlying device support flush? + * Does any underlying device not support WRITE_SAME? + * + * The callout function is called once for each contiguous section of + * an underlying device. State can be maintained in *data. + * Return non-zero to stop iterating through any further devices. + */ typedef int (*iterate_devices_callout_fn) (struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data); +/* + * This function must iterate through each section of device used by the + * target until it encounters a non-zero return code, which it then returns. + * Returns zero if no callout returned non-zero. + */ typedef int (*dm_iterate_devices_fn) (struct dm_target *ti, iterate_devices_callout_fn fn, void *data); @@ -104,12 +115,6 @@ 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; @@ -121,7 +126,7 @@ struct dm_dev { * are opened/closed correctly. */ int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, - struct dm_dev **result); + struct dm_dev **result); void dm_put_device(struct dm_target *ti, struct dm_dev *d); /* @@ -139,7 +144,6 @@ struct target_type { 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; @@ -180,6 +184,14 @@ struct target_type { #define DM_TARGET_IMMUTABLE 0x00000004 #define dm_target_is_immutable(type) ((type)->features & DM_TARGET_IMMUTABLE) +/* + * Some targets need to be sent the same WRITE bio severals times so + * that they can send copies of it to different devices. This function + * examines any supplied bio and returns the number of copies of it the + * target requires. + */ +typedef unsigned (*dm_num_write_bios_fn) (struct dm_target *ti, struct bio *bio); + struct dm_target { struct dm_table *table; struct target_type *type; @@ -188,24 +200,43 @@ struct dm_target { sector_t begin; sector_t len; - /* Always a power of 2 */ - sector_t split_io; + /* If non-zero, maximum size of I/O submitted to a target. */ + uint32_t max_io_len; /* - * A number of zero-length barrier requests that will be submitted + * A number of zero-length barrier bios that will be submitted * to the target for the purpose of flushing cache. * - * The request number will be placed in union map_info->target_request_nr. - * It is a responsibility of the target driver to remap these requests + * The bio number can be accessed with dm_bio_get_target_bio_nr. + * It is a responsibility of the target driver to remap these bios * to the real underlying devices. */ - unsigned num_flush_requests; + unsigned num_flush_bios; + + /* + * The number of discard bios that will be submitted to the target. + * The bio number can be accessed with dm_bio_get_target_bio_nr. + */ + unsigned num_discard_bios; + + /* + * The number of WRITE SAME bios that will be submitted to the target. + * The bio number can be accessed with dm_bio_get_target_bio_nr. + */ + unsigned num_write_same_bios; + + /* + * The minimum number of extra bytes allocated in each bio for the + * target to use. dm_per_bio_data returns the data location. + */ + unsigned per_bio_data_size; /* - * The number of discard requests that will be submitted to the - * target. map_info->request_nr is used just like num_flush_requests. + * If defined, this function is called to find out how many + * duplicate bios should be sent to the target when writing + * data. */ - unsigned num_discard_requests; + dm_num_write_bios_fn num_write_bios; /* target specific data */ void *private; @@ -214,15 +245,27 @@ struct dm_target { char *error; /* + * Set if this target needs to receive flushes regardless of + * whether or not its underlying devices have support. + */ + bool flush_supported:1; + + /* * Set if this target needs to receive discards regardless of * whether or not its underlying devices have support. */ - unsigned discards_supported:1; + bool discards_supported:1; + + /* + * Set if the target required discard bios to be split + * on max_io_len boundary. + */ + bool split_discard_bios:1; /* * Set if this target does not return zeroes on discarded blocks. */ - unsigned discard_zeroes_data_unsupported:1; + bool discard_zeroes_data_unsupported:1; }; /* Each target can link one of these into the table */ @@ -231,6 +274,36 @@ struct dm_target_callbacks { int (*congested_fn) (struct dm_target_callbacks *, int); }; +/* + * For bio-based dm. + * One of these is allocated for each bio. + * This structure shouldn't be touched directly by target drivers. + * It is here so that we can inline dm_per_bio_data and + * dm_bio_from_per_bio_data + */ +struct dm_target_io { + struct dm_io *io; + struct dm_target *ti; + unsigned target_bio_nr; + unsigned *len_ptr; + struct bio clone; +}; + +static inline void *dm_per_bio_data(struct bio *bio, size_t data_size) +{ + return (char *)bio - offsetof(struct dm_target_io, clone) - data_size; +} + +static inline struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size) +{ + return (struct bio *)((char *)data + data_size + offsetof(struct dm_target_io, clone)); +} + +static inline unsigned dm_bio_get_target_bio_nr(const struct bio *bio) +{ + return container_of(bio, struct dm_target_io, clone)->target_bio_nr; +} + int dm_register_target(struct target_type *t); void dm_unregister_target(struct target_type *t); @@ -323,16 +396,17 @@ 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 dm_target *ti); int dm_noflush_suspending(struct dm_target *ti); -union map_info *dm_get_mapinfo(struct bio *bio); +void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors); union map_info *dm_get_rq_mapinfo(struct request *rq); +struct queue_limits *dm_get_queue_limits(struct mapped_device *md); + /* * 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. *---------------------------------------------------------------*/ @@ -360,11 +434,16 @@ void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callback int dm_table_complete(struct dm_table *t); /* + * Target may require that it is never sent I/O larger than len. + */ +int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len); + +/* * Table reference counting. */ -struct dm_table *dm_get_live_table(struct mapped_device *md); -void dm_table_get(struct dm_table *t); -void dm_table_put(struct dm_table *t); +struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx); +void dm_put_live_table(struct mapped_device *md, int srcu_idx); +void dm_sync_table(struct mapped_device *md); /* * Queries @@ -380,6 +459,11 @@ struct mapped_device *dm_table_get_md(struct dm_table *t); void dm_table_event(struct dm_table *t); /* + * Run the queue for request-based targets. + */ +void dm_table_run_md_queue_async(struct dm_table *t); + +/* * The device must be suspended before calling this method. * Returns the previous table, which the caller must destroy. */ @@ -466,6 +550,14 @@ extern struct ratelimit_state dm_ratelimit_state; #define DM_MAPIO_REMAPPED 1 #define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE +#define dm_sector_div64(x, y)( \ +{ \ + u64 _res; \ + (x) = div64_u64_rem(x, y, &_res); \ + _res; \ +} \ +) + /* * Ceiling(n / sz) */ |