1 files changed, 30 insertions, 17 deletions

diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index ded2d7c42668..0d6310657f32 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -11,6 +11,7 @@
 #include <linux/bio.h>
 #include <linux/blkdev.h>
 
+struct dm_dev;
 struct dm_target;
 struct dm_table;
 struct mapped_device;
@@ -21,6 +22,7 @@ typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
 union map_info {
         void *ptr;
         unsigned long long ll;
+        unsigned flush_request;
 };
 
 /*
@@ -80,6 +82,15 @@ 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);
 
+typedef int (*iterate_devices_callout_fn) (struct dm_target *ti,
+                                           struct dm_dev *dev,
+                                           sector_t physical_start,
+                                           void *data);
+
+typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
+                                      iterate_devices_callout_fn fn,
+                                      void *data);
+
 /*
  * Returns:
  *    0: The target can handle the next I/O immediately.
@@ -92,7 +103,8 @@ void dm_error(const char *message);
 /*
  * Combine device limits.
  */
-void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev);
+int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
+                         sector_t start, void *data);
 
 struct dm_dev {
         struct block_device *bdev;
@@ -138,23 +150,12 @@ struct target_type {
         dm_ioctl_fn ioctl;
         dm_merge_fn merge;
         dm_busy_fn busy;
+        dm_iterate_devices_fn iterate_devices;
 
         /* For internal device-mapper use. */
         struct list_head list;
 };
 
-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;
@@ -163,15 +164,18 @@ struct dm_target {
         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.
+         * A number of zero-length barrier requests that will be submitted
+         * to the target for the purpose of flushing cache.
+         *
+         * The request number will be placed in union map_info->flush_request.
+         * It is a responsibility of the target driver to remap these requests
+         * to the real underlying devices.
          */
-        struct io_restrictions limits;
+        unsigned num_flush_requests;
 
         /* target specific data */
         void *private;
@@ -230,6 +234,7 @@ struct gendisk *dm_disk(struct mapped_device *md);
 int dm_suspended(struct mapped_device *md);
 int dm_noflush_suspending(struct dm_target *ti);
 union map_info *dm_get_mapinfo(struct bio *bio);
+union map_info *dm_get_rq_mapinfo(struct request *rq);
 
 /*
  * Geometry functions.
@@ -392,4 +397,12 @@ static inline unsigned long to_bytes(sector_t n)
         return (n << SECTOR_SHIFT);
 }
 
+/*-----------------------------------------------------------------
+ * Helper for block layer and dm core operations
+ *---------------------------------------------------------------*/
+void dm_dispatch_request(struct request *rq);
+void dm_requeue_unmapped_request(struct request *rq);
+void dm_kill_unmapped_request(struct request *rq, int error);
+int dm_underlying_device_busy(struct request_queue *q);
+
 #endif  /* _LINUX_DEVICE_MAPPER_H */