Merge tag 'libnvdimm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm...

[linux-2.6-block.git] / include / linux / device-mapper.h

diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 0830c9e86f0ddb94e897758724439df922721d97..91acfce74a220010549536edde925ef9e3ec81c0 100644 (file)
--- 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;
@@ -443,6 +461,14 @@ 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.
  */