[PATCH v2 23/63] dm/core: Combine request operation type and flags

[Bart Van Assche <bvanassche@acm.org>]

Improve kernel code uniformity by combining the request operation type and
flags into a single variable. Change 'int rw' into 'enum req_op op' because
the name 'op' is what is used in the block layer to hold a request type.
Use the blk_opf_t and enum req_op types where appropriate to improve static
type checking.

Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/md/dm-bufio.c | 19 ++++++++++---------
 drivers/md/dm-io.c    | 36 +++++++++++++++++-------------------
 drivers/md/dm.c       | 10 +++++-----
 3 files changed, 32 insertions(+), 33 deletions(-)

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index 1b7acda45c78..dc01ce33265b 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -577,12 +577,12 @@ static void dmio_complete(unsigned long error, void *context)
 	b->end_io(b, unlikely(error != 0) ? BLK_STS_IOERR : 0);
 }
 
-static void use_dmio(struct dm_buffer *b, int rw, sector_t sector,
+static void use_dmio(struct dm_buffer *b, enum req_op op, sector_t sector,
 		     unsigned n_sectors, unsigned offset)
 {
 	int r;
 	struct dm_io_request io_req = {
-		.bi_opf = rw,
+		.bi_opf = op,
 		.notify.fn = dmio_complete,
 		.notify.context = b,
 		.client = b->c->dm_io,
@@ -615,7 +615,7 @@ static void bio_complete(struct bio *bio)
 	b->end_io(b, status);
 }
 
-static void use_bio(struct dm_buffer *b, int rw, sector_t sector,
+static void use_bio(struct dm_buffer *b, enum req_op op, sector_t sector,
 		    unsigned n_sectors, unsigned offset)
 {
 	struct bio *bio;
@@ -629,10 +629,10 @@ static void use_bio(struct dm_buffer *b, int rw, sector_t sector,
 	bio = bio_kmalloc(vec_size, GFP_NOWAIT | __GFP_NORETRY | __GFP_NOWARN);
 	if (!bio) {
 dmio:
-		use_dmio(b, rw, sector, n_sectors, offset);
+		use_dmio(b, op, sector, n_sectors, offset);
 		return;
 	}
-	bio_init(bio, b->c->bdev, bio->bi_inline_vecs, vec_size, rw);
+	bio_init(bio, b->c->bdev, bio->bi_inline_vecs, vec_size, op);
 	bio->bi_iter.bi_sector = sector;
 	bio->bi_end_io = bio_complete;
 	bio->bi_private = b;
@@ -668,7 +668,8 @@ static inline sector_t block_to_sector(struct dm_bufio_client *c, sector_t block
 	return sector;
 }
 
-static void submit_io(struct dm_buffer *b, int rw, void (*end_io)(struct dm_buffer *, blk_status_t))
+static void submit_io(struct dm_buffer *b, enum req_op op,
+		      void (*end_io)(struct dm_buffer *, blk_status_t))
 {
 	unsigned n_sectors;
 	sector_t sector;
@@ -678,7 +679,7 @@ static void submit_io(struct dm_buffer *b, int rw, void (*end_io)(struct dm_buff
 
 	sector = block_to_sector(b->c, b->block);
 
-	if (rw != REQ_OP_WRITE) {
+	if (op != REQ_OP_WRITE) {
 		n_sectors = b->c->block_size >> SECTOR_SHIFT;
 		offset = 0;
 	} else {
@@ -697,9 +698,9 @@ static void submit_io(struct dm_buffer *b, int rw, void (*end_io)(struct dm_buff
 	}
 
 	if (b->data_mode != DATA_MODE_VMALLOC)
-		use_bio(b, rw, sector, n_sectors, offset);
+		use_bio(b, op, sector, n_sectors, offset);
 	else
-		use_dmio(b, rw, sector, n_sectors, offset);
+		use_dmio(b, op, sector, n_sectors, offset);
 }
 
 /*----------------------------------------------------------------
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 0606e00d1817..783564533459 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -293,7 +293,7 @@ static void km_dp_init(struct dpages *dp, void *data)
 /*-----------------------------------------------------------------
  * IO routines that accept a list of pages.
  *---------------------------------------------------------------*/
-static void do_region(int op, int op_flags, unsigned region,
+static void do_region(const blk_opf_t opf, unsigned region,
 		      struct dm_io_region *where, struct dpages *dp,
 		      struct io *io)
 {
@@ -306,6 +306,7 @@ static void do_region(int op, int op_flags, unsigned region,
 	struct request_queue *q = bdev_get_queue(where->bdev);
 	sector_t num_sectors;
 	unsigned int special_cmd_max_sectors;
+	const enum req_op op = opf & REQ_OP_MASK;
 
 	/*
 	 * Reject unsupported discard and write same requests.
@@ -339,8 +340,8 @@ static void do_region(int op, int op_flags, unsigned region,
 						(PAGE_SIZE >> SECTOR_SHIFT)));
 		}
 
-		bio = bio_alloc_bioset(where->bdev, num_bvecs, op | op_flags,
-				       GFP_NOIO, &io->client->bios);
+		bio = bio_alloc_bioset(where->bdev, num_bvecs, opf, GFP_NOIO,
+				       &io->client->bios);
 		bio->bi_iter.bi_sector = where->sector + (where->count - remaining);
 		bio->bi_end_io = endio;
 		store_io_and_region_in_bio(bio, io, region);
@@ -368,7 +369,7 @@ static void do_region(int op, int op_flags, unsigned region,
 	} while (remaining);
 }
 
-static void dispatch_io(int op, int op_flags, unsigned int num_regions,
+static void dispatch_io(blk_opf_t opf, unsigned int num_regions,
 			struct dm_io_region *where, struct dpages *dp,
 			struct io *io, int sync)
 {
@@ -378,7 +379,7 @@ static void dispatch_io(int op, int op_flags, unsigned int num_regions,
 	BUG_ON(num_regions > DM_IO_MAX_REGIONS);
 
 	if (sync)
-		op_flags |= REQ_SYNC;
+		opf |= REQ_SYNC;
 
 	/*
 	 * For multiple regions we need to be careful to rewind
@@ -386,8 +387,8 @@ static void dispatch_io(int op, int op_flags, unsigned int num_regions,
 	 */
 	for (i = 0; i < num_regions; i++) {
 		*dp = old_pages;
-		if (where[i].count || (op_flags & REQ_PREFLUSH))
-			do_region(op, op_flags, i, where + i, dp, io);
+		if (where[i].count || (opf & REQ_PREFLUSH))
+			do_region(opf, i, where + i, dp, io);
 	}
 
 	/*
@@ -411,13 +412,13 @@ static void sync_io_complete(unsigned long error, void *context)
 }
 
 static int sync_io(struct dm_io_client *client, unsigned int num_regions,
-		   struct dm_io_region *where, int op, int op_flags,
-		   struct dpages *dp, unsigned long *error_bits)
+		   struct dm_io_region *where, blk_opf_t opf, struct dpages *dp,
+		   unsigned long *error_bits)
 {
 	struct io *io;
 	struct sync_io sio;
 
-	if (num_regions > 1 && !op_is_write(op)) {
+	if (num_regions > 1 && !op_is_write(opf)) {
 		WARN_ON(1);
 		return -EIO;
 	}
@@ -434,7 +435,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions,
 	io->vma_invalidate_address = dp->vma_invalidate_address;
 	io->vma_invalidate_size = dp->vma_invalidate_size;
 
-	dispatch_io(op, op_flags, num_regions, where, dp, io, 1);
+	dispatch_io(opf, num_regions, where, dp, io, 1);
 
 	wait_for_completion_io(&sio.wait);
 
@@ -445,12 +446,12 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions,
 }
 
 static int async_io(struct dm_io_client *client, unsigned int num_regions,
-		    struct dm_io_region *where, int op, int op_flags,
+		    struct dm_io_region *where, blk_opf_t opf,
 		    struct dpages *dp, io_notify_fn fn, void *context)
 {
 	struct io *io;
 
-	if (num_regions > 1 && !op_is_write(op)) {
+	if (num_regions > 1 && !op_is_write(opf)) {
 		WARN_ON(1);
 		fn(1, context);
 		return -EIO;
@@ -466,7 +467,7 @@ static int async_io(struct dm_io_client *client, unsigned int num_regions,
 	io->vma_invalidate_address = dp->vma_invalidate_address;
 	io->vma_invalidate_size = dp->vma_invalidate_size;
 
-	dispatch_io(op, op_flags, num_regions, where, dp, io, 0);
+	dispatch_io(opf, num_regions, where, dp, io, 0);
 	return 0;
 }
 
@@ -519,13 +520,10 @@ int dm_io(struct dm_io_request *io_req, unsigned num_regions,
 
 	if (!io_req->notify.fn)
 		return sync_io(io_req->client, num_regions, where,
-			       io_req->bi_opf & REQ_OP_MASK,
-			       io_req->bi_opf & ~REQ_OP_MASK, &dp,
-			       sync_error_bits);
+			       io_req->bi_opf, &dp, sync_error_bits);
 
 	return async_io(io_req->client, num_regions, where,
-			io_req->bi_opf & REQ_OP_MASK,
-			io_req->bi_opf & ~REQ_OP_MASK, &dp, io_req->notify.fn,
+			io_req->bi_opf, &dp, io_req->notify.fn,
 			io_req->notify.context);
 }
 EXPORT_SYMBOL(dm_io);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index c6e004157da3..438b8791265c 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -716,7 +716,7 @@ static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
 }
 
 static inline struct dm_table *dm_get_live_table_bio(struct mapped_device *md,
-						     int *srcu_idx, unsigned bio_opf)
+					int *srcu_idx, blk_opf_t bio_opf)
 {
 	if (bio_opf & REQ_NOWAIT)
 		return dm_get_live_table_fast(md);
@@ -725,7 +725,7 @@ static inline struct dm_table *dm_get_live_table_bio(struct mapped_device *md,
 }
 
 static inline void dm_put_live_table_bio(struct mapped_device *md, int srcu_idx,
-					 unsigned bio_opf)
+					 blk_opf_t bio_opf)
 {
 	if (bio_opf & REQ_NOWAIT)
 		dm_put_live_table_fast(md);
@@ -1511,7 +1511,7 @@ static void __send_changing_extent_only(struct clone_info *ci, struct dm_target
 
 static bool is_abnormal_io(struct bio *bio)
 {
-	unsigned int op = bio_op(bio);
+	enum req_op op = bio_op(bio);
 
 	if (op != REQ_OP_READ && op != REQ_OP_WRITE && op != REQ_OP_FLUSH) {
 		switch (op) {
@@ -1625,7 +1625,7 @@ static blk_status_t __split_and_process_bio(struct clone_info *ci)
 	 * Only support bio polling for normal IO, and the target io is
 	 * exactly inside the dm_io instance (verified in dm_poll_dm_io)
 	 */
-	ci->submit_as_polled = ci->bio->bi_opf & REQ_POLLED;
+	ci->submit_as_polled = !!(ci->bio->bi_opf & REQ_POLLED);
 
 	len = min_t(sector_t, max_io_len(ti, ci->sector), ci->sector_count);
 	setup_split_accounting(ci, len);
@@ -1722,7 +1722,7 @@ static void dm_submit_bio(struct bio *bio)
 	struct mapped_device *md = bio->bi_bdev->bd_disk->private_data;
 	int srcu_idx;
 	struct dm_table *map;
-	unsigned bio_opf = bio->bi_opf;
+	blk_opf_t bio_opf = bio->bi_opf;
 
 	map = dm_get_live_table_bio(md, &srcu_idx, bio_opf);