1 files changed, 49 insertions, 9 deletions
diff --git a/drivers/md/dm-bio-prison.h b/drivers/md/dm-bio-prison.h
index 53d1a7a84e2f..3f833190eadf 100644
--- a/drivers/md/dm-bio-prison.h
+++ b/drivers/md/dm-bio-prison.h
@@ -22,7 +22,6 @@
 * subsequently unlocked the bios become available.
 */
 struct dm_bio_prison;
-struct dm_bio_prison_cell;
 /* FIXME: this needs to be more abstract */
 struct dm_cell_key {
@@ -31,21 +30,62 @@ struct dm_cell_key {
        dm_block_t block;
 };
+/*
+ * Treat this as opaque, only in header so callers can manage allocation
+ * themselves.
+ */
+struct dm_bio_prison_cell {
+        struct hlist_node list;
+        struct dm_cell_key key;
+        struct bio *holder;
+        struct bio_list bios;
+};
 struct dm_bio_prison *dm_bio_prison_create(unsigned nr_cells);
 void dm_bio_prison_destroy(struct dm_bio_prison *prison);
 /*
- * This may block if a new cell needs allocating.  You must ensure that
+ * These two functions just wrap a mempool.  This is a transitory step:
- * cells will be unlocked even if the calling thread is blocked.
+ * Eventually all bio prison clients should manage their own cell memory.
 *
- * Returns 1 if the cell was already held, 0 if @inmate is the new holder.
+ * Like mempool_alloc(), dm_bio_prison_alloc_cell() can only fail if called
+ * in interrupt context or passed GFP_NOWAIT.
 */
-int dm_bio_detain(struct dm_bio_prison *prison, struct dm_cell_key *key,
+struct dm_bio_prison_cell *dm_bio_prison_alloc_cell(struct dm_bio_prison *prison,
-                  struct bio *inmate, struct dm_bio_prison_cell **ref);
+                                                    gfp_t gfp);
+void dm_bio_prison_free_cell(struct dm_bio_prison *prison,
+                             struct dm_bio_prison_cell *cell);
-void dm_cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios);
+/*
-void dm_cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates);
+ * Creates, or retrieves a cell for the given key.
-void dm_cell_error(struct dm_bio_prison_cell *cell);
+ *
+ * Returns 1 if pre-existing cell returned, zero if new cell created using
+ * @cell_prealloc.
+ */
+int dm_get_cell(struct dm_bio_prison *prison,
+                struct dm_cell_key *key,
+                struct dm_bio_prison_cell *cell_prealloc,
+                struct dm_bio_prison_cell **cell_result);
+/*
+ * An atomic op that combines retrieving a cell, and adding a bio to it.
+ *
+ * Returns 1 if the cell was already held, 0 if @inmate is the new holder.
+ */
+int dm_bio_detain(struct dm_bio_prison *prison,
+                  struct dm_cell_key *key,
+                  struct bio *inmate,
+                  struct dm_bio_prison_cell *cell_prealloc,
+                  struct dm_bio_prison_cell **cell_result);
+void dm_cell_release(struct dm_bio_prison *prison,
+                     struct dm_bio_prison_cell *cell,
+                     struct bio_list *bios);
+void dm_cell_release_no_holder(struct dm_bio_prison *prison,
+                               struct dm_bio_prison_cell *cell,
+                               struct bio_list *inmates);
+void dm_cell_error(struct dm_bio_prison *prison,
+                   struct dm_bio_prison_cell *cell);
 /*----------------------------------------------------------------*/

diff --git a/drivers/md/dm-bio-prison.h b/drivers/md/dm-bio-prison.h index 53d1a7a84e2f..3f833190eadf 100644 --- a/drivers/md/dm-bio-prison.h +++ b/drivers/md/dm-bio-prison.h
@@ -22,7 +22,6 @@
22	* subsequently unlocked the bios become available.	22	* subsequently unlocked the bios become available.
23	*/	23	*/
24	struct dm_bio_prison;	24	struct dm_bio_prison;
25	struct dm_bio_prison_cell;
26		25
27	/* FIXME: this needs to be more abstract */	26	/* FIXME: this needs to be more abstract */
28	struct dm_cell_key {	27	struct dm_cell_key {
@@ -31,21 +30,62 @@ struct dm_cell_key {
31	dm_block_t block;	30	dm_block_t block;
32	};	31	};
33		32
		33	/*
		34	* Treat this as opaque, only in header so callers can manage allocation
		35	* themselves.
		36	*/
		37	struct dm_bio_prison_cell {
		38	struct hlist_node list;
		39	struct dm_cell_key key;
		40	struct bio *holder;
		41	struct bio_list bios;
		42	};
		43
34	struct dm_bio_prison *dm_bio_prison_create(unsigned nr_cells);	44	struct dm_bio_prison *dm_bio_prison_create(unsigned nr_cells);
35	void dm_bio_prison_destroy(struct dm_bio_prison *prison);	45	void dm_bio_prison_destroy(struct dm_bio_prison *prison);
36		46
37	/*	47	/*
38	* This may block if a new cell needs allocating. You must ensure that	48	* These two functions just wrap a mempool. This is a transitory step:
39	* cells will be unlocked even if the calling thread is blocked.	49	* Eventually all bio prison clients should manage their own cell memory.
40	*	50	*
41	* Returns 1 if the cell was already held, 0 if @inmate is the new holder.	51	* Like mempool_alloc(), dm_bio_prison_alloc_cell() can only fail if called
		52	* in interrupt context or passed GFP_NOWAIT.
42	*/	53	*/
43	int dm_bio_detain(struct dm_bio_prison prison, struct dm_cell_key key,	54	struct dm_bio_prison_cell dm_bio_prison_alloc_cell(struct dm_bio_prison prison,
44	struct bio inmate, struct dm_bio_prison_cell *ref);	55	gfp_t gfp);
		56	void dm_bio_prison_free_cell(struct dm_bio_prison *prison,
		57	struct dm_bio_prison_cell *cell);
45		58
46	void dm_cell_release(struct dm_bio_prison_cell cell, struct bio_list bios);	59	/*
47	void dm_cell_release_no_holder(struct dm_bio_prison_cell cell, struct bio_list inmates);	60	* Creates, or retrieves a cell for the given key.
48	void dm_cell_error(struct dm_bio_prison_cell *cell);	61	*
		62	* Returns 1 if pre-existing cell returned, zero if new cell created using
		63	* @cell_prealloc.
		64	*/
		65	int dm_get_cell(struct dm_bio_prison *prison,
		66	struct dm_cell_key *key,
		67	struct dm_bio_prison_cell *cell_prealloc,
		68	struct dm_bio_prison_cell **cell_result);
		69
		70	/*
		71	* An atomic op that combines retrieving a cell, and adding a bio to it.
		72	*
		73	* Returns 1 if the cell was already held, 0 if @inmate is the new holder.
		74	*/
		75	int dm_bio_detain(struct dm_bio_prison *prison,
		76	struct dm_cell_key *key,
		77	struct bio *inmate,
		78	struct dm_bio_prison_cell *cell_prealloc,
		79	struct dm_bio_prison_cell **cell_result);
		80
		81	void dm_cell_release(struct dm_bio_prison *prison,
		82	struct dm_bio_prison_cell *cell,
		83	struct bio_list *bios);
		84	void dm_cell_release_no_holder(struct dm_bio_prison *prison,
		85	struct dm_bio_prison_cell *cell,
		86	struct bio_list *inmates);
		87	void dm_cell_error(struct dm_bio_prison *prison,
		88	struct dm_bio_prison_cell *cell);
49		89
50	/----------------------------------------------------------------/	90	/----------------------------------------------------------------/
51		91