X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=blobdiff_plain;f=block%2Fdeadline-iosched.c;h=b547cbca7b23a55dd9d1f0b444bed07d297fc646;hp=8300ba1f15a09841ed0beff8a1085a5af3d5c3fc;hb=dc7a08166f3a5f23e79e839a8a88849bd3397c32;hpb=b8aca35af5e9fbc2e41a3ba1b2e66f24e80ca9b6

diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index 8300ba1..b547cbc 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -1,7 +1,7 @@
 /*
  *  Deadline i/o scheduler.
  *
- *  Copyright (C) 2002 Jens Axboe <axboe@suse.de>
+ *  Copyright (C) 2002 Jens Axboe <axboe@kernel.dk>
  */
 #include <linux/kernel.h>
 #include <linux/fs.h>
@@ -33,11 +33,11 @@ struct deadline_data {
 	 */
 	struct rb_root sort_list[2];	
 	struct list_head fifo_list[2];
-	
+
 	/*
 	 * next in sort order. read, write or both are NULL
 	 */
-	struct deadline_rq *next_drq[2];
+	struct request *next_rq[2];
 	unsigned int batching;		/* number of sequential requests made */
 	sector_t last_sector;		/* head position */
 	unsigned int starved;		/* times reads have starved writes */
@@ -49,96 +49,82 @@ struct deadline_data {
 	int fifo_batch;
 	int writes_starved;
 	int front_merges;
-
-	mempool_t *drq_pool;
 };
 
-/*
- * pre-request data.
- */
-struct deadline_rq {
-	struct request *request;
-
-	/*
-	 * expire fifo
-	 */
-	struct list_head fifo;
-	unsigned long expires;
-};
+static void deadline_move_request(struct deadline_data *, struct request *);
 
-static void deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq);
+static inline struct rb_root *
+deadline_rb_root(struct deadline_data *dd, struct request *rq)
+{
+	return &dd->sort_list[rq_data_dir(rq)];
+}
 
-static kmem_cache_t *drq_pool;
+/*
+ * get the request after `rq' in sector-sorted order
+ */
+static inline struct request *
+deadline_latter_request(struct request *rq)
+{
+	struct rb_node *node = rb_next(&rq->rb_node);
 
-#define RQ_DATA(rq)	((struct deadline_rq *) (rq)->elevator_private)
+	if (node)
+		return rb_entry_rq(node);
 
-#define RQ_RB_ROOT(dd, rq)	(&(dd)->sort_list[rq_data_dir((rq))])
-#define DRQ_RB_ROOT(dd, drq)	RQ_RB_ROOT((drq)->request)
+	return NULL;
+}
 
 static void
-deadline_add_drq_rb(struct deadline_data *dd, struct request *rq)
+deadline_add_rq_rb(struct deadline_data *dd, struct request *rq)
 {
-	struct rb_root *root = RQ_RB_ROOT(dd, rq);
+	struct rb_root *root = deadline_rb_root(dd, rq);
 	struct request *__alias;
 
-retry:
-	__alias = elv_rb_add(root, rq);
-	if (unlikely(__alias)) {
-		deadline_move_request(dd, RQ_DATA(__alias));
-		goto retry;
-	}
+	while (unlikely(__alias = elv_rb_add(root, rq)))
+		deadline_move_request(dd, __alias);
 }
 
 static inline void
-deadline_del_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
+deadline_del_rq_rb(struct deadline_data *dd, struct request *rq)
 {
-	struct request *rq = drq->request;
 	const int data_dir = rq_data_dir(rq);
 
-	if (dd->next_drq[data_dir] == drq) {
-		struct rb_node *rbnext = rb_next(&rq->rb_node);
-
-		dd->next_drq[data_dir] = NULL;
-		if (rbnext)
-			dd->next_drq[data_dir] = RQ_DATA(rb_entry_rq(rbnext));
-	}
+	if (dd->next_rq[data_dir] == rq)
+		dd->next_rq[data_dir] = deadline_latter_request(rq);
 
-	elv_rb_del(RQ_RB_ROOT(dd, rq), rq);
+	elv_rb_del(deadline_rb_root(dd, rq), rq);
 }
 
 /*
- * add drq to rbtree and fifo
+ * add rq to rbtree and fifo
  */
 static void
 deadline_add_request(struct request_queue *q, struct request *rq)
 {
 	struct deadline_data *dd = q->elevator->elevator_data;
-	struct deadline_rq *drq = RQ_DATA(rq);
-	const int data_dir = rq_data_dir(drq->request);
+	const int data_dir = rq_data_dir(rq);
 
-	deadline_add_drq_rb(dd, rq);
+	deadline_add_rq_rb(dd, rq);
 
 	/*
-	 * set expire time (only used for reads) and add to fifo list
+	 * set expire time and add to fifo list
 	 */
-	drq->expires = jiffies + dd->fifo_expire[data_dir];
-	list_add_tail(&drq->fifo, &dd->fifo_list[data_dir]);
+	rq_set_fifo_time(rq, jiffies + dd->fifo_expire[data_dir]);
+	list_add_tail(&rq->queuelist, &dd->fifo_list[data_dir]);
 }
 
 /*
  * remove rq from rbtree and fifo.
  */
-static void deadline_remove_request(request_queue_t *q, struct request *rq)
+static void deadline_remove_request(struct request_queue *q, struct request *rq)
 {
-	struct deadline_rq *drq = RQ_DATA(rq);
 	struct deadline_data *dd = q->elevator->elevator_data;
 
-	list_del_init(&drq->fifo);
-	deadline_del_drq_rb(dd, drq);
+	rq_fifo_clear(rq);
+	deadline_del_rq_rb(dd, rq);
 }
 
 static int
-deadline_merge(request_queue_t *q, struct request **req, struct bio *bio)
+deadline_merge(struct request_queue *q, struct request **req, struct bio *bio)
 {
 	struct deadline_data *dd = q->elevator->elevator_data;
 	struct request *__rq;
@@ -152,7 +138,7 @@ deadline_merge(request_queue_t *q, struct request **req, struct bio *bio)
 
 		__rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector);
 		if (__rq) {
-			BUG_ON(sector != __rq->sector);
+			BUG_ON(sector != blk_rq_pos(__rq));
 
 			if (elv_rq_merge_ok(__rq, bio)) {
 				ret = ELEVATOR_FRONT_MERGE;
@@ -167,8 +153,8 @@ out:
 	return ret;
 }
 
-static void deadline_merged_request(request_queue_t *q, struct request *req,
-				    int type)
+static void deadline_merged_request(struct request_queue *q,
+				    struct request *req, int type)
 {
 	struct deadline_data *dd = q->elevator->elevator_data;
 
@@ -176,29 +162,23 @@ static void deadline_merged_request(request_queue_t *q, struct request *req,
 	 * if the merge was a front merge, we need to reposition request
 	 */
 	if (type == ELEVATOR_FRONT_MERGE) {
-		elv_rb_del(RQ_RB_ROOT(dd, req), req);
-		deadline_add_drq_rb(dd, req);
+		elv_rb_del(deadline_rb_root(dd, req), req);
+		deadline_add_rq_rb(dd, req);
 	}
 }
 
 static void
-deadline_merged_requests(request_queue_t *q, struct request *req,
+deadline_merged_requests(struct request_queue *q, struct request *req,
 			 struct request *next)
 {
-	struct deadline_rq *drq = RQ_DATA(req);
-	struct deadline_rq *dnext = RQ_DATA(next);
-
-	BUG_ON(!drq);
-	BUG_ON(!dnext);
-
 	/*
-	 * if dnext expires before drq, assign its expire time to drq
-	 * and move into dnext position (dnext will be deleted) in fifo
+	 * if next expires before rq, assign its expire time to rq
+	 * and move into next position (next will be deleted) in fifo
 	 */
-	if (!list_empty(&drq->fifo) && !list_empty(&dnext->fifo)) {
-		if (time_before(dnext->expires, drq->expires)) {
-			list_move(&drq->fifo, &dnext->fifo);
-			drq->expires = dnext->expires;
+	if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
+		if (time_before(rq_fifo_time(next), rq_fifo_time(req))) {
+			list_move(&req->queuelist, &next->queuelist);
+			rq_set_fifo_time(req, rq_fifo_time(next));
 		}
 	}
 
@@ -212,53 +192,47 @@ deadline_merged_requests(request_queue_t *q, struct request *req,
  * move request from sort list to dispatch queue.
  */
 static inline void
-deadline_move_to_dispatch(struct deadline_data *dd, struct deadline_rq *drq)
+deadline_move_to_dispatch(struct deadline_data *dd, struct request *rq)
 {
-	request_queue_t *q = drq->request->q;
+	struct request_queue *q = rq->q;
 
-	deadline_remove_request(q, drq->request);
-	elv_dispatch_add_tail(q, drq->request);
+	deadline_remove_request(q, rq);
+	elv_dispatch_add_tail(q, rq);
 }
 
 /*
  * move an entry to dispatch queue
  */
 static void
-deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq)
+deadline_move_request(struct deadline_data *dd, struct request *rq)
 {
-	struct request *rq = drq->request;
 	const int data_dir = rq_data_dir(rq);
-	struct rb_node *rbnext = rb_next(&rq->rb_node);
 
-	dd->next_drq[READ] = NULL;
-	dd->next_drq[WRITE] = NULL;
+	dd->next_rq[READ] = NULL;
+	dd->next_rq[WRITE] = NULL;
+	dd->next_rq[data_dir] = deadline_latter_request(rq);
 
-	if (rbnext)
-		dd->next_drq[data_dir] = RQ_DATA(rb_entry_rq(rbnext));
-	
-	dd->last_sector = drq->request->sector + drq->request->nr_sectors;
+	dd->last_sector = rq_end_sector(rq);
 
 	/*
 	 * take it off the sort and fifo list, move
 	 * to dispatch queue
 	 */
-	deadline_move_to_dispatch(dd, drq);
+	deadline_move_to_dispatch(dd, rq);
 }
 
-#define list_entry_fifo(ptr)	list_entry((ptr), struct deadline_rq, fifo)
-
 /*
- * deadline_check_fifo returns 0 if there are no expired reads on the fifo,
+ * deadline_check_fifo returns 0 if there are no expired requests on the fifo,
  * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir])
  */
 static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
 {
-	struct deadline_rq *drq = list_entry_fifo(dd->fifo_list[ddir].next);
+	struct request *rq = rq_entry_fifo(dd->fifo_list[ddir].next);
 
 	/*
-	 * drq is expired!
+	 * rq is expired!
 	 */
-	if (time_after(jiffies, drq->expires))
+	if (time_after(jiffies, rq_fifo_time(rq)))
 		return 1;
 
 	return 0;
@@ -268,33 +242,25 @@ static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
  * deadline_dispatch_requests selects the best request according to
  * read/write expire, fifo_batch, etc
  */
-static int deadline_dispatch_requests(request_queue_t *q, int force)
+static int deadline_dispatch_requests(struct request_queue *q, int force)
 {
 	struct deadline_data *dd = q->elevator->elevator_data;
 	const int reads = !list_empty(&dd->fifo_list[READ]);
 	const int writes = !list_empty(&dd->fifo_list[WRITE]);
-	struct deadline_rq *drq;
+	struct request *rq;
 	int data_dir;
 
 	/*
 	 * batches are currently reads XOR writes
 	 */
-	if (dd->next_drq[WRITE])
-		drq = dd->next_drq[WRITE];
+	if (dd->next_rq[WRITE])
+		rq = dd->next_rq[WRITE];
 	else
-		drq = dd->next_drq[READ];
-
-	if (drq) {
-		/* we have a "next request" */
-		
-		if (dd->last_sector != drq->request->sector)
-			/* end the batch on a non sequential request */
-			dd->batching += dd->fifo_batch;
-		
-		if (dd->batching < dd->fifo_batch)
-			/* we are still entitled to batch */
-			goto dispatch_request;
-	}
+		rq = dd->next_rq[READ];
+
+	if (rq && dd->batching < dd->fifo_batch)
+		/* we have a next request are still entitled to batch */
+		goto dispatch_request;
 
 	/*
 	 * at this point we are not running a batch. select the appropriate
@@ -333,42 +299,34 @@ dispatch_find_request:
 	/*
 	 * we are not running a batch, find best request for selected data_dir
 	 */
-	if (deadline_check_fifo(dd, data_dir)) {
-		/* An expired request exists - satisfy it */
-		dd->batching = 0;
-		drq = list_entry_fifo(dd->fifo_list[data_dir].next);
-		
-	} else if (dd->next_drq[data_dir]) {
+	if (deadline_check_fifo(dd, data_dir) || !dd->next_rq[data_dir]) {
 		/*
-		 * The last req was the same dir and we have a next request in
-		 * sort order. No expired requests so continue on from here.
+		 * A deadline has expired, the last request was in the other
+		 * direction, or we have run out of higher-sectored requests.
+		 * Start again from the request with the earliest expiry time.
 		 */
-		drq = dd->next_drq[data_dir];
+		rq = rq_entry_fifo(dd->fifo_list[data_dir].next);
 	} else {
-		struct rb_node *n;
-
 		/*
-		 * The last req was the other direction or we have run out of
-		 * higher-sectored requests. Go back to the lowest sectored
-		 * request (1 way elevator) and start a new batch.
+		 * The last req was the same dir and we have a next request in
+		 * sort order. No expired requests so continue on from here.
 		 */
-		dd->batching = 0;
-		n = rb_first(&dd->sort_list[data_dir]);
-		if (n)
-			drq = RQ_DATA(rb_entry_rq(n));
+		rq = dd->next_rq[data_dir];
 	}
 
+	dd->batching = 0;
+
 dispatch_request:
 	/*
-	 * drq is the selected appropriate request.
+	 * rq is the selected appropriate request.
 	 */
 	dd->batching++;
-	deadline_move_request(dd, drq);
+	deadline_move_request(dd, rq);
 
 	return 1;
 }
 
-static int deadline_queue_empty(request_queue_t *q)
+static int deadline_queue_empty(struct request_queue *q)
 {
 	struct deadline_data *dd = q->elevator->elevator_data;
 
@@ -376,39 +334,26 @@ static int deadline_queue_empty(request_queue_t *q)
 		&& list_empty(&dd->fifo_list[READ]);
 }
 
-static void deadline_exit_queue(elevator_t *e)
+static void deadline_exit_queue(struct elevator_queue *e)
 {
 	struct deadline_data *dd = e->elevator_data;
 
 	BUG_ON(!list_empty(&dd->fifo_list[READ]));
 	BUG_ON(!list_empty(&dd->fifo_list[WRITE]));
 
-	mempool_destroy(dd->drq_pool);
 	kfree(dd);
 }
 
 /*
- * initialize elevator private data (deadline_data), and alloc a drq for
- * each request on the free lists
+ * initialize elevator private data (deadline_data).
  */
-static void *deadline_init_queue(request_queue_t *q, elevator_t *e)
+static void *deadline_init_queue(struct request_queue *q)
 {
 	struct deadline_data *dd;
 
-	if (!drq_pool)
-		return NULL;
-
-	dd = kmalloc_node(sizeof(*dd), GFP_KERNEL, q->node);
+	dd = kmalloc_node(sizeof(*dd), GFP_KERNEL | __GFP_ZERO, q->node);
 	if (!dd)
 		return NULL;
-	memset(dd, 0, sizeof(*dd));
-
-	dd->drq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab,
-					mempool_free_slab, drq_pool, q->node);
-	if (!dd->drq_pool) {
-		kfree(dd);
-		return NULL;
-	}
 
 	INIT_LIST_HEAD(&dd->fifo_list[READ]);
 	INIT_LIST_HEAD(&dd->fifo_list[WRITE]);
@@ -422,36 +367,6 @@ static void *deadline_init_queue(request_queue_t *q, elevator_t *e)
 	return dd;
 }
 
-static void deadline_put_request(request_queue_t *q, struct request *rq)
-{
-	struct deadline_data *dd = q->elevator->elevator_data;
-	struct deadline_rq *drq = RQ_DATA(rq);
-
-	mempool_free(drq, dd->drq_pool);
-	rq->elevator_private = NULL;
-}
-
-static int
-deadline_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
-		     gfp_t gfp_mask)
-{
-	struct deadline_data *dd = q->elevator->elevator_data;
-	struct deadline_rq *drq;
-
-	drq = mempool_alloc(dd->drq_pool, gfp_mask);
-	if (drq) {
-		memset(drq, 0, sizeof(*drq));
-		drq->request = rq;
-
-		INIT_LIST_HEAD(&drq->fifo);
-
-		rq->elevator_private = drq;
-		return 0;
-	}
-
-	return 1;
-}
-
 /*
  * sysfs parts below
  */
@@ -472,7 +387,7 @@ deadline_var_store(int *var, const char *page, size_t count)
 }
 
 #define SHOW_FUNCTION(__FUNC, __VAR, __CONV)				\
-static ssize_t __FUNC(elevator_t *e, char *page)			\
+static ssize_t __FUNC(struct elevator_queue *e, char *page)		\
 {									\
 	struct deadline_data *dd = e->elevator_data;			\
 	int __data = __VAR;						\
@@ -488,7 +403,7 @@ SHOW_FUNCTION(deadline_fifo_batch_show, dd->fifo_batch, 0);
 #undef SHOW_FUNCTION
 
 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV)			\
-static ssize_t __FUNC(elevator_t *e, const char *page, size_t count)	\
+static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)	\
 {									\
 	struct deadline_data *dd = e->elevator_data;			\
 	int __data;							\
@@ -533,8 +448,6 @@ static struct elevator_type iosched_deadline = {
 		.elevator_queue_empty_fn =	deadline_queue_empty,
 		.elevator_former_req_fn =	elv_rb_former_request,
 		.elevator_latter_req_fn =	elv_rb_latter_request,
-		.elevator_set_req_fn =		deadline_set_request,
-		.elevator_put_req_fn = 		deadline_put_request,
 		.elevator_init_fn =		deadline_init_queue,
 		.elevator_exit_fn =		deadline_exit_queue,
 	},
@@ -546,24 +459,13 @@ static struct elevator_type iosched_deadline = {
 
 static int __init deadline_init(void)
 {
-	int ret;
-
-	drq_pool = kmem_cache_create("deadline_drq", sizeof(struct deadline_rq),
-				     0, 0, NULL, NULL);
-
-	if (!drq_pool)
-		return -ENOMEM;
+	elv_register(&iosched_deadline);
 
-	ret = elv_register(&iosched_deadline);
-	if (ret)
-		kmem_cache_destroy(drq_pool);
-
-	return ret;
+	return 0;
 }
 
 static void __exit deadline_exit(void)
 {
-	kmem_cache_destroy(drq_pool);
 	elv_unregister(&iosched_deadline);
 }