From 0b6e522cdc4a76352e5f02fc2d92198f03254425 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 24 Jan 2021 11:02:38 +0100 Subject: [PATCH] blk-mq: use ->bi_bdev for I/O accounting Remove the reverse map from a sector to a partition for I/O accounting by simply using ->bi_bdev. Signed-off-by: Christoph Hellwig Acked-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-core.c | 6 +++++- block/blk.h | 2 -- block/genhd.c | 48 ------------------------------------------------ 3 files changed, 5 insertions(+), 51 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 9315311c27a9..6dfbdde6b9ff 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1298,7 +1298,11 @@ void blk_account_io_start(struct request *rq) if (!blk_do_io_stat(rq)) return; - rq->part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq)); + /* passthrough requests can hold bios that do not have ->bi_bdev set */ + if (rq->bio && rq->bio->bi_bdev) + rq->part = rq->bio->bi_bdev; + else + rq->part = rq->rq_disk->part0; part_stat_lock(); update_io_ticks(rq->part, jiffies, false); diff --git a/block/blk.h b/block/blk.h index 10ab7c0d0766..d965cacc5bda 100644 --- a/block/blk.h +++ b/block/blk.h @@ -333,8 +333,6 @@ void blk_queue_free_zone_bitmaps(struct request_queue *q); static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {} #endif -struct block_device *disk_map_sector_rcu(struct gendisk *disk, sector_t sector); - int blk_alloc_devt(struct block_device *part, dev_t *devt); void blk_free_devt(dev_t devt); char *disk_name(struct gendisk *hd, int partno, char *buf); diff --git a/block/genhd.c b/block/genhd.c index e536d0b4bbae..e46de616a19e 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -285,54 +285,6 @@ void disk_part_iter_exit(struct disk_part_iter *piter) } EXPORT_SYMBOL_GPL(disk_part_iter_exit); -static inline int sector_in_part(struct block_device *part, sector_t sector) -{ - return part->bd_start_sect <= sector && - sector < part->bd_start_sect + bdev_nr_sectors(part); -} - -/** - * disk_map_sector_rcu - map sector to partition - * @disk: gendisk of interest - * @sector: sector to map - * - * Find out which partition @sector maps to on @disk. This is - * primarily used for stats accounting. - * - * CONTEXT: - * RCU read locked. - * - * RETURNS: - * Found partition on success, part0 is returned if no partition matches - * or the matched partition is being deleted. - */ -struct block_device *disk_map_sector_rcu(struct gendisk *disk, sector_t sector) -{ - struct disk_part_tbl *ptbl; - struct block_device *part; - int i; - - rcu_read_lock(); - ptbl = rcu_dereference(disk->part_tbl); - - part = rcu_dereference(ptbl->last_lookup); - if (part && sector_in_part(part, sector)) - goto out_unlock; - - for (i = 1; i < ptbl->len; i++) { - part = rcu_dereference(ptbl->part[i]); - if (part && sector_in_part(part, sector)) { - rcu_assign_pointer(ptbl->last_lookup, part); - goto out_unlock; - } - } - - part = disk->part0; -out_unlock: - rcu_read_unlock(); - return part; -} - /** * disk_has_partitions * @disk: gendisk of interest