1 files changed, 21 insertions, 7 deletions

diff --git a/drivers/md/dm-bio-prison.h b/drivers/md/dm-bio-prison.h
index 6805a142b750..74cf01144b1f 100644
--- a/drivers/md/dm-bio-prison.h
+++ b/drivers/md/dm-bio-prison.h
@@ -10,8 +10,8 @@
 #include "persistent-data/dm-block-manager.h" /* FIXME: for dm_block_t */
 #include "dm-thin-metadata.h" /* FIXME: for dm_thin_id */
 
-#include <linux/list.h>
 #include <linux/bio.h>
+#include <linux/rbtree.h>
 
 /*----------------------------------------------------------------*/
 
@@ -23,11 +23,14 @@
  */
 struct dm_bio_prison;
 
-/* FIXME: this needs to be more abstract */
+/*
+ * Keys define a range of blocks within either a virtual or physical
+ * device.
+ */
 struct dm_cell_key {
         int virtual;
         dm_thin_id dev;
-        dm_block_t block;
+        dm_block_t block_begin, block_end;
 };
 
 /*
@@ -35,13 +38,15 @@ struct dm_cell_key {
  * themselves.
  */
 struct dm_bio_prison_cell {
-        struct hlist_node list;
+        struct list_head user_list;     /* for client use */
+        struct rb_node node;
+
         struct dm_cell_key key;
         struct bio *holder;
         struct bio_list bios;
 };
 
-struct dm_bio_prison *dm_bio_prison_create(unsigned nr_cells);
+struct dm_bio_prison *dm_bio_prison_create(void);
 void dm_bio_prison_destroy(struct dm_bio_prison *prison);
 
 /*
@@ -57,7 +62,7 @@ void dm_bio_prison_free_cell(struct dm_bio_prison *prison,
                              struct dm_bio_prison_cell *cell);
 
 /*
- * Creates, or retrieves a cell for the given key.
+ * Creates, or retrieves a cell that overlaps the given key.
  *
  * Returns 1 if pre-existing cell returned, zero if new cell created using
  * @cell_prealloc.
@@ -68,7 +73,8 @@ int dm_get_cell(struct dm_bio_prison *prison,
                 struct dm_bio_prison_cell **cell_result);
 
 /*
- * An atomic op that combines retrieving a cell, and adding a bio to it.
+ * An atomic op that combines retrieving or creating a cell, and adding a
+ * bio to it.
  *
  * Returns 1 if the cell was already held, 0 if @inmate is the new holder.
  */
@@ -87,6 +93,14 @@ void dm_cell_release_no_holder(struct dm_bio_prison *prison,
 void dm_cell_error(struct dm_bio_prison *prison,
                    struct dm_bio_prison_cell *cell, int error);
 
+/*
+ * Visits the cell and then releases.  Guarantees no new inmates are
+ * inserted between the visit and release.
+ */
+void dm_cell_visit_release(struct dm_bio_prison *prison,
+                           void (*visit_fn)(void *, struct dm_bio_prison_cell *),
+                           void *context, struct dm_bio_prison_cell *cell);
+
 /*----------------------------------------------------------------*/
 
 /*