block: rename REQ_HIPRI to REQ_POLLED

Unlike the RWF_HIPRI userspace ABI which is intentionally kept vague,
the bio flag is specific to the polling implementation, so rename and
document it properly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-12-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-core.c

@@ -842,7 +842,7 @@ static noinline_for_stack bool submit_bio_checks(struct bio *bio)
 	}
 
 	if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
-		bio_clear_hipri(bio);
+		bio_clear_polled(bio);
 
 	switch (bio_op(bio)) {
 	case REQ_OP_DISCARD:

block/blk-merge.c

@@ -318,8 +318,7 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
 	 * iopoll in direct IO routine. Given performance gain of iopoll for
 	 * big IO can be trival, disable iopoll when split needed.
 	 */
-	bio_clear_hipri(bio);
-
+	bio_clear_polled(bio);
 	return bio_split(bio, sectors, GFP_NOIO, bs);
 }
 

block/blk-mq-debugfs.c

@@ -287,7 +287,7 @@ static const char *const cmd_flag_name[] = {
 	CMD_FLAG_NAME(BACKGROUND),
 	CMD_FLAG_NAME(NOWAIT),
 	CMD_FLAG_NAME(NOUNMAP),
-	CMD_FLAG_NAME(HIPRI),
+	CMD_FLAG_NAME(POLLED),
 };
 #undef CMD_FLAG_NAME
 

block/blk-mq.c

@@ -732,7 +732,7 @@ bool blk_mq_complete_request_remote(struct request *rq)
 	 * For a polled request, always complete locallly, it's pointless
 	 * to redirect the completion.
 	 */
-	if (rq->cmd_flags & REQ_HIPRI)
+	if (rq->cmd_flags & REQ_POLLED)
 		return false;
 
 	if (blk_mq_complete_need_ipi(rq)) {
@@ -2278,7 +2278,7 @@ blk_qc_t blk_mq_submit_bio(struct bio *bio)
 
 	rq_qos_throttle(q, bio);
 
-	hipri = bio->bi_opf & REQ_HIPRI;
+	hipri = bio->bi_opf & REQ_POLLED;
 
 	plug = blk_mq_plug(q, bio);
 	if (plug && plug->cached_rq) {

block/blk-mq.h

@@ -106,9 +106,9 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
 	enum hctx_type type = HCTX_TYPE_DEFAULT;
 
 	/*
-	 * The caller ensure that if REQ_HIPRI, poll must be enabled.
+	 * The caller ensure that if REQ_POLLED, poll must be enabled.
 	 */
-	if (flags & REQ_HIPRI)
+	if (flags & REQ_POLLED)
 		type = HCTX_TYPE_POLL;
 	else if ((flags & REQ_OP_MASK) == REQ_OP_READ)
 		type = HCTX_TYPE_READ;

block/blk.h

@@ -416,11 +416,11 @@ extern struct device_attribute dev_attr_events;
 extern struct device_attribute dev_attr_events_async;
 extern struct device_attribute dev_attr_events_poll_msecs;
 
-static inline void bio_clear_hipri(struct bio *bio)
+static inline void bio_clear_polled(struct bio *bio)
 {
 	/* can't support alloc cache if we turn off polling */
 	bio_clear_flag(bio, BIO_PERCPU_CACHE);
-	bio->bi_opf &= ~REQ_HIPRI;
+	bio->bi_opf &= ~REQ_POLLED;
 }
 
 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);

drivers/nvme/host/core.c

@@ -632,7 +632,7 @@ static inline void nvme_init_request(struct request *req,
 
 	req->cmd_flags |= REQ_FAILFAST_DRIVER;
 	if (req->mq_hctx->type == HCTX_TYPE_POLL)
-		req->cmd_flags |= REQ_HIPRI;
+		req->cmd_flags |= REQ_POLLED;
 	nvme_clear_nvme_request(req);
 	memcpy(nvme_req(req)->cmd, cmd, sizeof(*cmd));
 }

drivers/scsi/scsi_debug.c

@@ -5384,7 +5384,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
 {
 	bool new_sd_dp;
 	bool inject = false;
-	bool hipri = scsi_cmd_to_rq(cmnd)->cmd_flags & REQ_HIPRI;
+	bool polled = scsi_cmd_to_rq(cmnd)->cmd_flags & REQ_POLLED;
 	int k, num_in_q, qdepth;
 	unsigned long iflags;
 	u64 ns_from_boot = 0;
@@ -5471,7 +5471,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
 	if (sdebug_host_max_queue)
 		sd_dp->hc_idx = get_tag(cmnd);
 
-	if (hipri)
+	if (polled)
 		ns_from_boot = ktime_get_boottime_ns();
 
 	/* one of the resp_*() response functions is called here */
@@ -5531,7 +5531,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
 				kt -= d;
 			}
 		}
-		if (hipri) {
+		if (polled) {
 			sd_dp->cmpl_ts = ktime_add(ns_to_ktime(ns_from_boot), kt);
 			spin_lock_irqsave(&sqp->qc_lock, iflags);
 			if (!sd_dp->init_poll) {
@@ -5562,7 +5562,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
 		if (unlikely((sdebug_opts & SDEBUG_OPT_CMD_ABORT) &&
 			     atomic_read(&sdeb_inject_pending)))
 			sd_dp->aborted = true;
-		if (hipri) {
+		if (polled) {
 			sd_dp->cmpl_ts = ns_to_ktime(ns_from_boot);
 			spin_lock_irqsave(&sqp->qc_lock, iflags);
 			if (!sd_dp->init_poll) {
@@ -7331,7 +7331,7 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
 			if (kt_from_boot < sd_dp->cmpl_ts)
 				continue;
 
-		} else		/* ignoring non REQ_HIPRI requests */
+		} else		/* ignoring non REQ_POLLED requests */
 			continue;
 		devip = (struct sdebug_dev_info *)scp->device->hostdata;
 		if (likely(devip))

include/linux/bio.h

@@ -706,7 +706,7 @@ static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
  */
 static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
 {
-	bio->bi_opf |= REQ_HIPRI;
+	bio->bi_opf |= REQ_POLLED;
 	if (!is_sync_kiocb(kiocb))
 		bio->bi_opf |= REQ_NOWAIT;
 }

include/linux/blk_types.h

@@ -384,7 +384,7 @@ enum req_flag_bits {
 	/* command specific flags for REQ_OP_WRITE_ZEROES: */
 	__REQ_NOUNMAP,		/* do not free blocks when zeroing */
 
-	__REQ_HIPRI,
+	__REQ_POLLED,		/* caller polls for completion using blk_poll */
 
 	/* for driver use */
 	__REQ_DRV,
@@ -409,7 +409,7 @@ enum req_flag_bits {
 #define REQ_CGROUP_PUNT		(1ULL << __REQ_CGROUP_PUNT)
 
 #define REQ_NOUNMAP		(1ULL << __REQ_NOUNMAP)
-#define REQ_HIPRI		(1ULL << __REQ_HIPRI)
+#define REQ_POLLED		(1ULL << __REQ_POLLED)
 
 #define REQ_DRV			(1ULL << __REQ_DRV)
 #define REQ_SWAP		(1ULL << __REQ_SWAP)

mm/page_io.c

@@ -416,7 +416,7 @@ int swap_readpage(struct page *page, bool synchronous)
 	 * attempt to access it in the page fault retry time check.
 	 */
 	if (synchronous) {
-		bio->bi_opf |= REQ_HIPRI;
+		bio->bi_opf |= REQ_POLLED;
 		get_task_struct(current);
 		bio->bi_private = current;
 	}