diff options
| -rw-r--r-- | drivers/md/dm-thin.c | 89 |
1 files changed, 15 insertions, 74 deletions
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index d2bbe8cc1e97..49e358a0c22f 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -332,9 +332,6 @@ struct thin_c { * * Description: * Asynchronously issue a discard request for the sectors in question. - * NOTE: this variant of blk-core's blkdev_issue_discard() is a stop-gap - * that is being kept local to DM thinp until the block changes to allow - * late bio splitting land upstream. */ static int __blkdev_issue_discard_async(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, unsigned long flags, @@ -342,91 +339,36 @@ static int __blkdev_issue_discard_async(struct block_device *bdev, sector_t sect { struct request_queue *q = bdev_get_queue(bdev); int type = REQ_WRITE | REQ_DISCARD; - unsigned int max_discard_sectors, granularity; - int alignment; struct bio *bio; - int ret = 0; - struct blk_plug plug; - if (!q) + if (!q || !nr_sects) return -ENXIO; if (!blk_queue_discard(q)) return -EOPNOTSUPP; - /* Zero-sector (unknown) and one-sector granularities are the same. */ - granularity = max(q->limits.discard_granularity >> 9, 1U); - alignment = (bdev_discard_alignment(bdev) >> 9) % granularity; - - /* - * Ensure that max_discard_sectors is of the proper - * granularity, so that requests stay aligned after a split. - */ - max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); - max_discard_sectors -= max_discard_sectors % granularity; - if (unlikely(!max_discard_sectors)) { - /* Avoid infinite loop below. Being cautious never hurts. */ - return -EOPNOTSUPP; - } - if (flags & BLKDEV_DISCARD_SECURE) { if (!blk_queue_secdiscard(q)) return -EOPNOTSUPP; type |= REQ_SECURE; } - blk_start_plug(&plug); - while (nr_sects) { - unsigned int req_sects; - sector_t end_sect, tmp; - - /* - * Required bio_put occurs in bio_endio thanks to bio_chain below - */ - bio = bio_alloc(gfp_mask, 1); - if (!bio) { - ret = -ENOMEM; - break; - } - - req_sects = min_t(sector_t, nr_sects, max_discard_sectors); - - /* - * If splitting a request, and the next starting sector would be - * misaligned, stop the discard at the previous aligned sector. - */ - end_sect = sector + req_sects; - tmp = end_sect; - if (req_sects < nr_sects && - sector_div(tmp, granularity) != alignment) { - end_sect = end_sect - alignment; - sector_div(end_sect, granularity); - end_sect = end_sect * granularity + alignment; - req_sects = end_sect - sector; - } - - bio_chain(bio, parent_bio); - - bio->bi_iter.bi_sector = sector; - bio->bi_bdev = bdev; + /* + * Required bio_put occurs in bio_endio thanks to bio_chain below + */ + bio = bio_alloc(gfp_mask, 1); + if (!bio) + return -ENOMEM; - bio->bi_iter.bi_size = req_sects << 9; - nr_sects -= req_sects; - sector = end_sect; + bio_chain(bio, parent_bio); - submit_bio(type, bio); + bio->bi_iter.bi_sector = sector; + bio->bi_bdev = bdev; + bio->bi_iter.bi_size = nr_sects << 9; - /* - * We can loop for a long time in here, if someone does - * full device discards (like mkfs). Be nice and allow - * us to schedule out to avoid softlocking if preempt - * is disabled. - */ - cond_resched(); - } - blk_finish_plug(&plug); + submit_bio(type, bio); - return ret; + return 0; } static bool block_size_is_power_of_two(struct pool *pool) @@ -1539,9 +1481,8 @@ static void process_discard_cell_no_passdown(struct thin_c *tc, } /* - * FIXME: DM local hack to defer parent bios's end_io until we - * _know_ all chained sub range discard bios have completed. - * Will go away once late bio splitting lands upstream! + * __bio_inc_remaining() is used to defer parent bios's end_io until + * we _know_ all chained sub range discard bios have completed. */ static inline void __bio_inc_remaining(struct bio *bio) { |