dm: add local variables to clone_endio and __map_bio

Avoid redundant dereferences in both functions. Signed-off-by: Mike Snitzer <snitzer@kernel.org>

Author: Mike Snitzer

drivers/md/dm.c

@@ -976,11 +976,12 @@ static bool swap_bios_limit(struct dm_target *ti, struct bio *bio)
 static void clone_endio(struct bio *bio)
 {
 blk_status_t error = bio->bi_status;
+struct request_queue *q = bio->bi_bdev->bd_disk->queue;
 struct dm_target_io *tio = clone_to_tio(bio);
+struct dm_target *ti = tio->ti;
+dm_endio_fn endio = ti->type->end_io;
 struct dm_io *io = tio->io;
-struct mapped_device *md = tio->io->md;
-dm_endio_fn endio = tio->ti->type->end_io;
-struct request_queue *q = bio->bi_bdev->bd_disk->queue;
+struct mapped_device *md = io->md;
 
 if (unlikely(error == BLK_STS_TARGET)) {
 if (bio_op(bio) == REQ_OP_DISCARD &&
@@ -995,7 +996,7 @@ static void clone_endio(struct bio *bio)
 dm_zone_endio(io, bio);
 
 if (endio) {
-int r = endio(tio->ti, bio, &error);
+int r = endio(ti, bio, &error);
 switch (r) {
 case DM_ENDIO_REQUEUE:
 /*
@@ -1019,10 +1020,8 @@ static void clone_endio(struct bio *bio)
 }
 }
 
-if (unlikely(swap_bios_limit(tio->ti, bio))) {
-struct mapped_device *md = io->md;
+if (unlikely(swap_bios_limit(ti, bio)))
 up(&md->swap_bios_semaphore);
-}
 
 free_tio(bio);
 dm_io_dec_pending(io, error);
@@ -1263,9 +1262,10 @@ static noinline void __set_swap_bios_limit(struct mapped_device *md, int latch)
 static void __map_bio(struct bio *clone)
 {
 struct dm_target_io *tio = clone_to_tio(clone);
-int r;
-struct dm_io *io = tio->io;
 struct dm_target *ti = tio->ti;
+struct dm_io *io = tio->io;
+struct mapped_device *md = io->md;
+int r;
 
 clone->bi_end_io = clone_endio;
 
@@ -1276,7 +1276,6 @@ static void __map_bio(struct bio *clone)
 tio->old_sector = clone->bi_iter.bi_sector;
 
 if (unlikely(swap_bios_limit(ti, clone))) {
-struct mapped_device *md = io->md;
 int latch = get_swap_bios();
 if (unlikely(latch != md->swap_bios))
 __set_swap_bios_limit(md, latch);
@@ -1288,7 +1287,7 @@ static void __map_bio(struct bio *clone)
  * on zoned target. In this case, dm_zone_map_bio() calls the target
  * map operation.
  */
-if (unlikely(dm_emulate_zone_append(io->md)))
+if (unlikely(dm_emulate_zone_append(md)))
 r = dm_zone_map_bio(tio);
 else
 r = ti->type->map(ti, clone);
@@ -1304,14 +1303,14 @@ static void __map_bio(struct bio *clone)
  * the bio has been remapped so dispatch it, but defer
  * dm_start_io_acct() until after possible bio_split().
  */
-__dm_submit_bio_remap(clone, disk_devt(io->md->disk),
+__dm_submit_bio_remap(clone, disk_devt(md->disk),
  tio->old_sector);
 dm_io_set_flag(io, DM_IO_START_ACCT);
 break;
 case DM_MAPIO_KILL:
 case DM_MAPIO_REQUEUE:
 if (unlikely(swap_bios_limit(ti, clone)))
-up(&io->md->swap_bios_semaphore);
+up(&md->swap_bios_semaphore);
 free_tio(clone);
 if (r == DM_MAPIO_KILL)
 dm_io_dec_pending(io, BLK_STS_IOERR);