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-rw-r--r--include/linux/device-mapper.h26
1 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 0830c9e86f0d..91acfce74a22 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -19,6 +19,15 @@ struct dm_table;
struct mapped_device;
struct bio_vec;
+/*
+ * Type of table, mapped_device's mempool and request_queue
+ */
+#define DM_TYPE_NONE 0
+#define DM_TYPE_BIO_BASED 1
+#define DM_TYPE_REQUEST_BASED 2
+#define DM_TYPE_MQ_REQUEST_BASED 3
+#define DM_TYPE_DAX_BIO_BASED 4
+
typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
union map_info {
@@ -116,6 +125,14 @@ typedef void (*dm_io_hints_fn) (struct dm_target *ti,
*/
typedef int (*dm_busy_fn) (struct dm_target *ti);
+/*
+ * Returns:
+ * < 0 : error
+ * >= 0 : the number of bytes accessible at the address
+ */
+typedef long (*dm_direct_access_fn) (struct dm_target *ti, sector_t sector,
+ void **kaddr, pfn_t *pfn, long size);
+
void dm_error(const char *message);
struct dm_dev {
@@ -162,6 +179,7 @@ struct target_type {
dm_busy_fn busy;
dm_iterate_devices_fn iterate_devices;
dm_io_hints_fn io_hints;
+ dm_direct_access_fn direct_access;
/* For internal device-mapper use. */
struct list_head list;
@@ -444,6 +462,14 @@ int dm_table_add_target(struct dm_table *t, const char *type,
void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb);
/*
+ * Target can use this to set the table's type.
+ * Can only ever be called from a target's ctr.
+ * Useful for "hybrid" target (supports both bio-based
+ * and request-based).
+ */
+void dm_table_set_type(struct dm_table *t, unsigned type);
+
+/*
* Finally call this to make the table ready for use.
*/
int dm_table_complete(struct dm_table *t);