X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=block%2Fcfq-iosched.c;h=07b706243772e46fe2434248bf0e4fba938fca0a;hb=c893779e9fbe78575cbd04596f1fcafdb48e8f3f;hp=84e9be073180253baab4cfddb69fbc2a4a14e764;hpb=8d1413b28033c49c7f1a4d320e815d7a5531acee;p=pandora-kernel.git

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 84e9be073180..07b706243772 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -43,8 +43,8 @@ static int cfq_slice_idle = HZ / 125;
 #define RQ_CIC(rq)		((struct cfq_io_context*)(rq)->elevator_private)
 #define RQ_CFQQ(rq)		((rq)->elevator_private2)
 
-static kmem_cache_t *cfq_pool;
-static kmem_cache_t *cfq_ioc_pool;
+static struct kmem_cache *cfq_pool;
+static struct kmem_cache *cfq_ioc_pool;
 
 static DEFINE_PER_CPU(unsigned long, ioc_count);
 static struct completion *ioc_gone;
@@ -219,9 +219,12 @@ static int cfq_queue_empty(request_queue_t *q)
 	return !cfqd->busy_queues;
 }
 
-static inline pid_t cfq_queue_pid(struct task_struct *task, int rw)
+static inline pid_t cfq_queue_pid(struct task_struct *task, int rw, int is_sync)
 {
-	if (rw == READ || rw == WRITE_SYNC)
+	/*
+	 * Use the per-process queue, for read requests and syncronous writes
+	 */
+	if (!(rw & REQ_RW) || is_sync)
 		return task->pid;
 
 	return CFQ_KEY_ASYNC;
@@ -473,7 +476,7 @@ static struct request *
 cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio)
 {
 	struct task_struct *tsk = current;
-	pid_t key = cfq_queue_pid(tsk, bio_data_dir(bio));
+	pid_t key = cfq_queue_pid(tsk, bio_data_dir(bio), bio_sync(bio));
 	struct cfq_queue *cfqq;
 
 	cfqq = cfq_find_cfq_hash(cfqd, key, tsk->ioprio);
@@ -565,6 +568,33 @@ cfq_merged_requests(request_queue_t *q, struct request *rq,
 	cfq_remove_request(next);
 }
 
+static int cfq_allow_merge(request_queue_t *q, struct request *rq,
+			   struct bio *bio)
+{
+	struct cfq_data *cfqd = q->elevator->elevator_data;
+	const int rw = bio_data_dir(bio);
+	struct cfq_queue *cfqq;
+	pid_t key;
+
+	/*
+	 * Disallow merge of a sync bio into an async request.
+	 */
+	if ((bio_data_dir(bio) == READ || bio_sync(bio)) && !rq_is_sync(rq))
+		return 0;
+
+	/*
+	 * Lookup the cfqq that this bio will be queued with. Allow
+	 * merge only if rq is queued there.
+	 */
+	key = cfq_queue_pid(current, rw, bio_sync(bio));
+	cfqq = cfq_find_cfq_hash(cfqd, key, current->ioprio);
+
+	if (cfqq == RQ_CFQQ(rq))
+		return 1;
+
+	return 0;
+}
+
 static inline void
 __cfq_set_active_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
@@ -1748,6 +1778,9 @@ static int cfq_may_queue(request_queue_t *q, int rw)
 	struct cfq_data *cfqd = q->elevator->elevator_data;
 	struct task_struct *tsk = current;
 	struct cfq_queue *cfqq;
+	unsigned int key;
+
+	key = cfq_queue_pid(tsk, rw, rw & REQ_RW_SYNC);
 
 	/*
 	 * don't force setup of a queue from here, as a call to may_queue
@@ -1755,7 +1788,7 @@ static int cfq_may_queue(request_queue_t *q, int rw)
 	 * so just lookup a possibly existing queue, or return 'may queue'
 	 * if that fails
 	 */
-	cfqq = cfq_find_cfq_hash(cfqd, cfq_queue_pid(tsk, rw), tsk->ioprio);
+	cfqq = cfq_find_cfq_hash(cfqd, key, tsk->ioprio);
 	if (cfqq) {
 		cfq_init_prio_data(cfqq);
 		cfq_prio_boost(cfqq);
@@ -1798,10 +1831,10 @@ cfq_set_request(request_queue_t *q, struct request *rq, gfp_t gfp_mask)
 	struct task_struct *tsk = current;
 	struct cfq_io_context *cic;
 	const int rw = rq_data_dir(rq);
-	pid_t key = cfq_queue_pid(tsk, rw);
+	const int is_sync = rq_is_sync(rq);
+	pid_t key = cfq_queue_pid(tsk, rw, is_sync);
 	struct cfq_queue *cfqq;
 	unsigned long flags;
-	int is_sync = key != CFQ_KEY_ASYNC;
 
 	might_sleep_if(gfp_mask & __GFP_WAIT);
 
@@ -2119,6 +2152,7 @@ static struct elevator_type iosched_cfq = {
 		.elevator_merge_fn = 		cfq_merge,
 		.elevator_merged_fn =		cfq_merged_request,
 		.elevator_merge_req_fn =	cfq_merged_requests,
+		.elevator_allow_merge_fn =	cfq_allow_merge,
 		.elevator_dispatch_fn =		cfq_dispatch_requests,
 		.elevator_add_req_fn =		cfq_insert_request,
 		.elevator_activate_req_fn =	cfq_activate_request,