Commit 17220ca5 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
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block: cache request queue in bdev 



There are tons of places where we need to get a request_queue only
having bdev, which turns into bdev->bd_disk->queue. There are probably a
hundred of such places considering inline helpers, and enough of them
are in hot paths.

Cache queue pointer in struct block_device and make use of it in
bdev_get_queue().

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a3bfaecdd28956f03629d0ca5c63ebc096e1c809.1634219547.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent abd45c15

block/bdev.c

+1 −0
Original line number Diff line number Diff line
@@ -493,6 +493,7 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) 
	spin_lock_init(&bdev->bd_size_lock);

	bdev->bd_partno = partno;

	bdev->bd_inode = inode;

	bdev->bd_queue = disk->queue;

	bdev->bd_stats = alloc_percpu(struct disk_stats);

	if (!bdev->bd_stats) {

		iput(inode);

block/genhd.c

+3 −1
Original line number Diff line number Diff line
@@ -1267,6 +1267,9 @@ struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id, 
	if (!disk->bdi)

		goto out_free_disk;



	/* bdev_alloc() might need the queue, set before the first call */

	disk->queue = q;



	disk->part0 = bdev_alloc(disk, 0);

	if (!disk->part0)

		goto out_free_bdi;
@@ -1282,7 +1285,6 @@ struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id, 
	disk_to_dev(disk)->type = &disk_type;

	device_initialize(disk_to_dev(disk));

	inc_diskseq(disk);

	disk->queue = q;

	q->disk = disk;

	lockdep_init_map(&disk->lockdep_map, "(bio completion)", lkclass, 0);

#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED

include/linux/blk_types.h

+1 −0
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ struct block_device { 
	u8			bd_partno;

	spinlock_t		bd_size_lock; /* for bd_inode->i_size updates */

	struct gendisk *	bd_disk;

	struct request_queue *	bd_queue;



	/* The counter of freeze processes */

	int			bd_fsfreeze_count;

include/linux/blkdev.h

+1 −1
Original line number Diff line number Diff line
@@ -574,7 +574,7 @@ int iocb_bio_iopoll(struct kiocb *kiocb, unsigned int flags); 


static inline struct request_queue *bdev_get_queue(struct block_device *bdev)

{

	return bdev->bd_disk->queue;	/* this is never NULL */

	return bdev->bd_queue;	/* this is never NULL */

}



/*