block: Use enum req_op where appropriate

Change the type of the arguments that are used to pass a REQ_OP_* value
from int or unsigned int into enum req_op to improve static type
checking.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-core.c

@@ -136,7 +136,7 @@ static const char *const blk_op_name[] = {
  * string format. Useful in the debugging and tracing bio or request. For
  * invalid REQ_OP_XXX it returns string "UNKNOWN".
  */
-inline const char *blk_op_str(unsigned int op)
+inline const char *blk_op_str(enum req_op op)
 {
 	const char *op_str = "UNKNOWN";
 
@@ -953,7 +953,7 @@ again:
 }
 
 unsigned long bdev_start_io_acct(struct block_device *bdev,
-				 unsigned int sectors, unsigned int op,
+				 unsigned int sectors, enum req_op op,
 				 unsigned long start_time)
 {
 	const int sgrp = op_stat_group(op);
@@ -994,7 +994,7 @@ unsigned long bio_start_io_acct(struct bio *bio)
 }
 EXPORT_SYMBOL_GPL(bio_start_io_acct);
 
-void bdev_end_io_acct(struct block_device *bdev, unsigned int op,
+void bdev_end_io_acct(struct block_device *bdev, enum req_op op,
 		      unsigned long start_time)
 {
 	const int sgrp = op_stat_group(op);

block/blk-mq-debugfs.c

@@ -304,7 +304,7 @@ static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 {
 	const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
-	const unsigned int op = req_op(rq);
+	const enum req_op op = req_op(rq);
 	const char *op_str = blk_op_str(op);
 
 	seq_printf(m, "%p {.op=", rq);

block/blk-throttle.c

@@ -2203,8 +2203,9 @@ out_unlock:
 
 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
 static void throtl_track_latency(struct throtl_data *td, sector_t size,
-	int op, unsigned long time)
+				 enum req_op op, unsigned long time)
 {
+	const bool rw = op_is_write(op);
 	struct latency_bucket *latency;
 	int index;
 
@@ -2215,10 +2216,10 @@ static void throtl_track_latency(struct throtl_data *td, sector_t size,
 
 	index = request_bucket_index(size);
 
-	latency = get_cpu_ptr(td->latency_buckets[op]);
+	latency = get_cpu_ptr(td->latency_buckets[rw]);
 	latency[index].total_latency += time;
 	latency[index].samples++;
-	put_cpu_ptr(td->latency_buckets[op]);
+	put_cpu_ptr(td->latency_buckets[rw]);
 }
 
 void blk_throtl_stat_add(struct request *rq, u64 time_ns)

block/blk-wbt.c

@@ -670,7 +670,7 @@ u64 wbt_default_latency_nsec(struct request_queue *q)
 
 static int wbt_data_dir(const struct request *rq)
 {
-	const int op = req_op(rq);
+	const enum req_op op = req_op(rq);
 
 	if (op == REQ_OP_READ)
 		return READ;

block/blk.h

@@ -160,7 +160,7 @@ static inline bool blk_discard_mergable(struct request *req)
 }
 
 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
-						     int op)
+						     enum req_op op)
 {
 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
 		return min(q->limits.max_discard_sectors,

include/linux/blk_types.h

@@ -522,7 +522,7 @@ static inline bool op_is_zone_mgmt(enum req_op op)
 	}
 }
 
-static inline int op_stat_group(unsigned int op)
+static inline int op_stat_group(enum req_op op)
 {
 	if (op_is_discard(op))
 		return STAT_DISCARD;

include/linux/blkdev.h

@@ -872,7 +872,7 @@ extern void blk_queue_exit(struct request_queue *q);
 extern void blk_sync_queue(struct request_queue *q);
 
 /* Helper to convert REQ_OP_XXX to its string format XXX */
-extern const char *blk_op_str(unsigned int op);
+extern const char *blk_op_str(enum req_op op);
 
 int blk_status_to_errno(blk_status_t status);
 blk_status_t errno_to_blk_status(int errno);
@@ -1434,9 +1434,9 @@ static inline void blk_wake_io_task(struct task_struct *waiter)
 }
 
 unsigned long bdev_start_io_acct(struct block_device *bdev,
-				 unsigned int sectors, unsigned int op,
+				 unsigned int sectors, enum req_op op,
 				 unsigned long start_time);
-void bdev_end_io_acct(struct block_device *bdev, unsigned int op,
+void bdev_end_io_acct(struct block_device *bdev, enum req_op op,
 		unsigned long start_time);
 
 void bio_start_io_acct_time(struct bio *bio, unsigned long start_time);