block: better op and flags encoding

Now that we don't need the common flags to overflow outside the range
of a 32-bit type we can encode them the same way for both the bio and
request fields.  This in addition allows us to place the operation
first (and make some room for more ops while we're at it) and to
stop having to shift around the operation values.

In addition this allows passing around only one value in the block layer
instead of two (and eventuall also in the file systems, but we can do
that later) and thus clean up a lot of code.

Last but not least this allows decreasing the size of the cmd_flags
field in struct request to 32-bits.  Various functions passing this
value could also be updated, but I'd like to avoid the churn for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 32 insertions, 34 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 5e24d880306c2..c96186adaa668 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -667,10 +667,10 @@ static inline void cfqg_put(struct cfq_group *cfqg)
 } while (0)
 
 static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg,
-					    struct cfq_group *curr_cfqg, int op,
-					    int op_flags)
+					    struct cfq_group *curr_cfqg,
+					    unsigned int op)
 {
-	blkg_rwstat_add(&cfqg->stats.queued, op, op_flags, 1);
+	blkg_rwstat_add(&cfqg->stats.queued, op, 1);
 	cfqg_stats_end_empty_time(&cfqg->stats);
 	cfqg_stats_set_start_group_wait_time(cfqg, curr_cfqg);
 }
@@ -684,30 +684,29 @@ static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg,
 #endif
 }
 
-static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int op,
-					       int op_flags)
+static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg,
+					       unsigned int op)
 {
-	blkg_rwstat_add(&cfqg->stats.queued, op, op_flags, -1);
+	blkg_rwstat_add(&cfqg->stats.queued, op, -1);
 }
 
-static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int op,
-					       int op_flags)
+static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg,
+					       unsigned int op)
 {
-	blkg_rwstat_add(&cfqg->stats.merged, op, op_flags, 1);
+	blkg_rwstat_add(&cfqg->stats.merged, op, 1);
 }
 
 static inline void cfqg_stats_update_completion(struct cfq_group *cfqg,
-			uint64_t start_time, uint64_t io_start_time, int op,
-			int op_flags)
+			uint64_t start_time, uint64_t io_start_time,
+			unsigned int op)
 {
 	struct cfqg_stats *stats = &cfqg->stats;
 	unsigned long long now = sched_clock();
 
 	if (time_after64(now, io_start_time))
-		blkg_rwstat_add(&stats->service_time, op, op_flags,
-				now - io_start_time);
+		blkg_rwstat_add(&stats->service_time, op, now - io_start_time);
 	if (time_after64(io_start_time, start_time))
-		blkg_rwstat_add(&stats->wait_time, op, op_flags,
+		blkg_rwstat_add(&stats->wait_time, op,
 				io_start_time - start_time);
 }
 
@@ -786,16 +785,16 @@ static inline void cfqg_put(struct cfq_group *cfqg) { }
 #define cfq_log_cfqg(cfqd, cfqg, fmt, args...)		do {} while (0)
 
 static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg,
-			struct cfq_group *curr_cfqg, int op, int op_flags) { }
+			struct cfq_group *curr_cfqg, unsigned int op) { }
 static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg,
 			uint64_t time, unsigned long unaccounted_time) { }
-static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int op,
-			int op_flags) { }
-static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int op,
-			int op_flags) { }
+static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg,
+			unsigned int op) { }
+static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg,
+			unsigned int op) { }
 static inline void cfqg_stats_update_completion(struct cfq_group *cfqg,
-			uint64_t start_time, uint64_t io_start_time, int op,
-			int op_flags) { }
+			uint64_t start_time, uint64_t io_start_time,
+			unsigned int op) { }
 
 #endif	/* CONFIG_CFQ_GROUP_IOSCHED */
 
@@ -2474,10 +2473,10 @@ static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq)
 {
 	elv_rb_del(&cfqq->sort_list, rq);
 	cfqq->queued[rq_is_sync(rq)]--;
-	cfqg_stats_update_io_remove(RQ_CFQG(rq), req_op(rq), rq->cmd_flags);
+	cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags);
 	cfq_add_rq_rb(rq);
 	cfqg_stats_update_io_add(RQ_CFQG(rq), cfqq->cfqd->serving_group,
-				 req_op(rq), rq->cmd_flags);
+				 rq->cmd_flags);
 }
 
 static struct request *
@@ -2530,7 +2529,7 @@ static void cfq_remove_request(struct request *rq)
 	cfq_del_rq_rb(rq);
 
 	cfqq->cfqd->rq_queued--;
-	cfqg_stats_update_io_remove(RQ_CFQG(rq), req_op(rq), rq->cmd_flags);
+	cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags);
 	if (rq->cmd_flags & REQ_PRIO) {
 		WARN_ON(!cfqq->prio_pending);
 		cfqq->prio_pending--;
@@ -2565,7 +2564,7 @@ static void cfq_merged_request(struct request_queue *q, struct request *req,
 static void cfq_bio_merged(struct request_queue *q, struct request *req,
 				struct bio *bio)
 {
-	cfqg_stats_update_io_merged(RQ_CFQG(req), bio_op(bio), bio->bi_opf);
+	cfqg_stats_update_io_merged(RQ_CFQG(req), bio->bi_opf);
 }
 
 static void
@@ -2588,7 +2587,7 @@ cfq_merged_requests(struct request_queue *q, struct request *rq,
 	if (cfqq->next_rq == next)
 		cfqq->next_rq = rq;
 	cfq_remove_request(next);
-	cfqg_stats_update_io_merged(RQ_CFQG(rq), req_op(next), next->cmd_flags);
+	cfqg_stats_update_io_merged(RQ_CFQG(rq), next->cmd_flags);
 
 	cfqq = RQ_CFQQ(next);
 	/*
@@ -4142,7 +4141,7 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq)
 	rq->fifo_time = ktime_get_ns() + cfqd->cfq_fifo_expire[rq_is_sync(rq)];
 	list_add_tail(&rq->queuelist, &cfqq->fifo);
 	cfq_add_rq_rb(rq);
-	cfqg_stats_update_io_add(RQ_CFQG(rq), cfqd->serving_group, req_op(rq),
+	cfqg_stats_update_io_add(RQ_CFQG(rq), cfqd->serving_group,
 				 rq->cmd_flags);
 	cfq_rq_enqueued(cfqd, cfqq, rq);
 }
@@ -4240,8 +4239,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
 	cfqq->dispatched--;
 	(RQ_CFQG(rq))->dispatched--;
 	cfqg_stats_update_completion(cfqq->cfqg, rq_start_time_ns(rq),
-				     rq_io_start_time_ns(rq), req_op(rq),
-				     rq->cmd_flags);
+				     rq_io_start_time_ns(rq), rq->cmd_flags);
 
 	cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;
 
@@ -4319,14 +4317,14 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
 		cfq_schedule_dispatch(cfqd);
 }
 
-static void cfqq_boost_on_prio(struct cfq_queue *cfqq, int op_flags)
+static void cfqq_boost_on_prio(struct cfq_queue *cfqq, unsigned int op)
 {
 	/*
 	 * If REQ_PRIO is set, boost class and prio level, if it's below
 	 * BE/NORM. If prio is not set, restore the potentially boosted
 	 * class/prio level.
 	 */
-	if (!(op_flags & REQ_PRIO)) {
+	if (!(op & REQ_PRIO)) {
 		cfqq->ioprio_class = cfqq->org_ioprio_class;
 		cfqq->ioprio = cfqq->org_ioprio;
 	} else {
@@ -4347,7 +4345,7 @@ static inline int __cfq_may_queue(struct cfq_queue *cfqq)
 	return ELV_MQUEUE_MAY;
 }
 
-static int cfq_may_queue(struct request_queue *q, int op, int op_flags)
+static int cfq_may_queue(struct request_queue *q, unsigned int op)
 {
 	struct cfq_data *cfqd = q->elevator->elevator_data;
 	struct task_struct *tsk = current;
@@ -4364,10 +4362,10 @@ static int cfq_may_queue(struct request_queue *q, int op, int op_flags)
 	if (!cic)
 		return ELV_MQUEUE_MAY;
 
-	cfqq = cic_to_cfqq(cic, rw_is_sync(op, op_flags));
+	cfqq = cic_to_cfqq(cic, op_is_sync(op));
 	if (cfqq) {
 		cfq_init_prio_data(cfqq, cic);
-		cfqq_boost_on_prio(cfqq, op_flags);
+		cfqq_boost_on_prio(cfqq, op);
 
 		return __cfq_may_queue(cfqq);
 	}