[PATCH] block: Remove needless request_queue NULL pointer checks

[Xu Wang]

The request_queue pointer returned from bdev_get_queue() shall
never be NULL, so the NULL checks are unnecessary, just remove them.

Signed-off-by: Xu Wang <vulab@xxxxxxxxxxx>
---
 block/blk-lib.c         | 14 --------------
 include/linux/blkdev.h  | 32 +++++++-------------------------
 kernel/trace/blktrace.c |  6 +-----
 3 files changed, 8 insertions(+), 44 deletions(-)

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 9f09beadcbe3..e6e854936ef6 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -32,9 +32,6 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	unsigned int op;
 	sector_t bs_mask, part_offset = 0;
 
-	if (!q)
-		return -ENXIO;
-
 	if (bdev_read_only(bdev))
 		return -EPERM;
 
@@ -172,9 +169,6 @@ static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	struct bio *bio = *biop;
 	sector_t bs_mask;
 
-	if (!q)
-		return -ENXIO;
-
 	if (bdev_read_only(bdev))
 		return -EPERM;
 
@@ -250,10 +244,6 @@ static int __blkdev_issue_write_zeroes(struct block_device *bdev,
 {
 	struct bio *bio = *biop;
 	unsigned int max_write_zeroes_sectors;
-	struct request_queue *q = bdev_get_queue(bdev);
-
-	if (!q)
-		return -ENXIO;
 
 	if (bdev_read_only(bdev))
 		return -EPERM;
@@ -304,14 +294,10 @@ static int __blkdev_issue_zero_pages(struct block_device *bdev,
 		sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
 		struct bio **biop)
 {
-	struct request_queue *q = bdev_get_queue(bdev);
 	struct bio *bio = *biop;
 	int bi_size = 0;
 	unsigned int sz;
 
-	if (!q)
-		return -ENXIO;
-
 	if (bdev_read_only(bdev))
 		return -EPERM;
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 12b9dbcc980e..9ab84ba1d7da 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1529,67 +1529,49 @@ static inline unsigned int bdev_write_same(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
 
-	if (q)
-		return q->limits.max_write_same_sectors;
-
-	return 0;
+	return q->limits.max_write_same_sectors;
 }
 
 static inline unsigned int bdev_write_zeroes_sectors(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
 
-	if (q)
-		return q->limits.max_write_zeroes_sectors;
-
-	return 0;
+	return q->limits.max_write_zeroes_sectors;
 }
 
 static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
 
-	if (q)
-		return blk_queue_zoned_model(q);
-
-	return BLK_ZONED_NONE;
+	return blk_queue_zoned_model(q);
 }
 
 static inline bool bdev_is_zoned(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
 
-	if (q)
-		return blk_queue_is_zoned(q);
-
-	return false;
+	return blk_queue_is_zoned(q);
 }
 
 static inline sector_t bdev_zone_sectors(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
 
-	if (q)
-		return blk_queue_zone_sectors(q);
-	return 0;
+	return blk_queue_zone_sectors(q);
 }
 
 static inline unsigned int bdev_max_open_zones(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
 
-	if (q)
-		return queue_max_open_zones(q);
-	return 0;
+	return queue_max_open_zones(q);
 }
 
 static inline unsigned int bdev_max_active_zones(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
 
-	if (q)
-		return queue_max_active_zones(q);
-	return 0;
+	return queue_max_active_zones(q);
 }
 
 static inline int queue_dma_alignment(const struct request_queue *q)
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index c221e4c3f625..2fe970d896b3 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -714,14 +714,10 @@ EXPORT_SYMBOL_GPL(blk_trace_startstop);
  **/
 int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
 {
-	struct request_queue *q;
+	struct request_queue *q = bdev_get_queue(bdev);
 	int ret, start = 0;
 	char b[BDEVNAME_SIZE];
 
-	q = bdev_get_queue(bdev);
-	if (!q)
-		return -ENXIO;
-
 	mutex_lock(&q->debugfs_mutex);
 
 	switch (cmd) {
-- 
2.17.1