diff options
| -rw-r--r-- | block/blk-lib.c | 31 | ||||
| -rw-r--r-- | block/blk.h | 14 |
2 files changed, 42 insertions, 3 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c index 5f2c429d4378..019e09bb9c0e 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -29,7 +29,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, struct request_queue *q = bdev_get_queue(bdev); struct bio *bio = *biop; unsigned int op; - sector_t bs_mask; + sector_t bs_mask, part_offset = 0; if (!q) return -ENXIO; @@ -54,9 +54,34 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, if (!nr_sects) return -EINVAL; + /* In case the discard request is in a partition */ + if (bdev->bd_partno) + part_offset = bdev->bd_part->start_sect; + while (nr_sects) { - sector_t req_sects = min_t(sector_t, nr_sects, - bio_allowed_max_sectors(q)); + sector_t granularity_aligned_lba, req_sects; + sector_t sector_mapped = sector + part_offset; + + granularity_aligned_lba = round_up(sector_mapped, + q->limits.discard_granularity >> SECTOR_SHIFT); + + /* + * Check whether the discard bio starts at a discard_granularity + * aligned LBA, + * - If no: set (granularity_aligned_lba - sector_mapped) to + * bi_size of the first split bio, then the second bio will + * start at a discard_granularity aligned LBA on the device. + * - If yes: use bio_aligned_discard_max_sectors() as the max + * possible bi_size of the first split bio. Then when this bio + * is split in device drive, the split ones are very probably + * to be aligned to discard_granularity of the device's queue. + */ + if (granularity_aligned_lba == sector_mapped) + req_sects = min_t(sector_t, nr_sects, + bio_aligned_discard_max_sectors(q)); + else + req_sects = min_t(sector_t, nr_sects, + granularity_aligned_lba - sector_mapped); WARN_ON_ONCE((req_sects << 9) > UINT_MAX); diff --git a/block/blk.h b/block/blk.h index 9dcf51c94096..49e2928a1632 100644 --- a/block/blk.h +++ b/block/blk.h @@ -265,6 +265,20 @@ static inline unsigned int bio_allowed_max_sectors(struct request_queue *q) } /* + * The max bio size which is aligned to q->limits.discard_granularity. This + * is a hint to split large discard bio in generic block layer, then if device + * driver needs to split the discard bio into smaller ones, their bi_size can + * be very probably and easily aligned to discard_granularity of the device's + * queue. + */ +static inline unsigned int bio_aligned_discard_max_sectors( + struct request_queue *q) +{ + return round_down(UINT_MAX, q->limits.discard_granularity) >> + SECTOR_SHIFT; +} + +/* * Internal io_context interface */ void get_io_context(struct io_context *ioc); |