aboutsummaryrefslogtreecommitdiff
path: root/include/linux/device-mapper.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/device-mapper.h')
-rw-r--r--include/linux/device-mapper.h49
1 files changed, 32 insertions, 17 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index bf6afa2fc432..1e483fa7afb4 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -68,8 +68,8 @@ 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,
- unsigned status_flags, char *result, unsigned 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);
@@ -175,6 +175,14 @@ 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;
@@ -187,26 +195,26 @@ struct dm_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 can be accessed with dm_bio_get_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 requests that will be submitted to the target.
- * The request number can be accessed with dm_bio_get_target_request_nr.
+ * 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_requests;
+ unsigned num_discard_bios;
/*
- * The number of WRITE SAME requests that will be submitted to the target.
- * The request number can be accessed with dm_bio_get_target_request_nr.
+ * 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_requests;
+ unsigned num_write_same_bios;
/*
* The minimum number of extra bytes allocated in each bio for the
@@ -214,6 +222,13 @@ struct dm_target {
*/
unsigned per_bio_data_size;
+ /*
+ * If defined, this function is called to find out how many
+ * duplicate bios should be sent to the target when writing
+ * data.
+ */
+ dm_num_write_bios_fn num_write_bios;
+
/* target specific data */
void *private;
@@ -233,10 +248,10 @@ struct dm_target {
bool discards_supported:1;
/*
- * Set if the target required discard request to be split
+ * Set if the target required discard bios to be split
* on max_io_len boundary.
*/
- bool split_discard_requests:1;
+ bool split_discard_bios:1;
/*
* Set if this target does not return zeroes on discarded blocks.
@@ -261,7 +276,7 @@ struct dm_target_io {
struct dm_io *io;
struct dm_target *ti;
union map_info info;
- unsigned target_request_nr;
+ unsigned target_bio_nr;
struct bio clone;
};
@@ -275,9 +290,9 @@ 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_request_nr(const struct bio *bio)
+static inline unsigned dm_bio_get_target_bio_nr(const struct bio *bio)
{
- return container_of(bio, struct dm_target_io, clone)->target_request_nr;
+ return container_of(bio, struct dm_target_io, clone)->target_bio_nr;
}
int dm_register_target(struct target_type *t);