block: remove more NULL checks after bdev_get_queue()

bdev_get_queue() never returns NULL. Several commits [1][2] have been made
before to remove such superfluous checks, but some still remained.

For places where bdev_get_queue() is called solely for NULL checks, it is
removed entirely.

[1] commit ec9fd2a ("blk-lib: don't check bdev_get_queue() NULL check")
[2] commit fea127b ("block: remove superfluous check for request queue in bdev_is_zoned()")

Signed-off-by: Juhyung Park <qkrwngud825@gmail.com>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20230203024029.48260-1-qkrwngud825@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: arter97

block/blk-zoned.c

@@ -334,17 +334,12 @@ int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
 {
 	void __user *argp = (void __user *)arg;
 	struct zone_report_args args;
-	struct request_queue *q;
 	struct blk_zone_report rep;
 	int ret;
 
 	if (!argp)
 		return -EINVAL;
 
-	q = bdev_get_queue(bdev);
-	if (!q)
-		return -ENXIO;
-
 	if (!bdev_is_zoned(bdev))
 		return -ENOTTY;
 
@@ -391,18 +386,13 @@ int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
 			   unsigned int cmd, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
-	struct request_queue *q;
 	struct blk_zone_range zrange;
 	enum req_op op;
 	int ret;
 
 	if (!argp)
 		return -EINVAL;
 
-	q = bdev_get_queue(bdev);
-	if (!q)
-		return -ENXIO;
-
 	if (!bdev_is_zoned(bdev))
 		return -ENOTTY;
 

include/linux/blkdev.h

@@ -1276,12 +1276,7 @@ static inline bool bdev_nowait(struct block_device *bdev)
 
 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(bdev_get_queue(bdev));
 }
 
 static inline bool bdev_is_zoned(struct block_device *bdev)

kernel/trace/blktrace.c

@@ -729,14 +729,10 @@ 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) {