diff options
Diffstat (limited to 'block/blk-lib.c')
| -rw-r--r-- | block/blk-lib.c | 58 |
1 files changed, 56 insertions, 2 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c index bfb28b0..510a6fb 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -227,6 +227,55 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, EXPORT_SYMBOL(blkdev_issue_write_same); /** + * __blkdev_issue_write_zeroes - generate number of bios with WRITE ZEROES + * @bdev: blockdev to issue + * @sector: start sector + * @nr_sects: number of sectors to write + * @gfp_mask: memory allocation flags (for bio_alloc) + * @biop: pointer to anchor bio + * + * Description: + * Generate and issue number of bios(REQ_OP_WRITE_ZEROES) with zerofiled pages. + */ +static int __blkdev_issue_write_zeroes(struct block_device *bdev, + sector_t sector, sector_t nr_sects, gfp_t gfp_mask, + struct bio **biop) +{ + struct bio *bio = *biop; + unsigned int max_write_zeroes_sectors; + struct request_queue *q = bdev_get_queue(bdev); + + if (!q) + return -ENXIO; + + /* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */ + max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev); + + if (max_write_zeroes_sectors == 0) + return -EOPNOTSUPP; + + while (nr_sects) { + bio = next_bio(bio, 0, gfp_mask); + bio->bi_iter.bi_sector = sector; + bio->bi_bdev = bdev; + bio_set_op_attrs(bio, REQ_OP_WRITE_ZEROES, 0); + + if (nr_sects > max_write_zeroes_sectors) { + bio->bi_iter.bi_size = max_write_zeroes_sectors << 9; + nr_sects -= max_write_zeroes_sectors; + sector += max_write_zeroes_sectors; + } else { + bio->bi_iter.bi_size = nr_sects << 9; + nr_sects = 0; + } + cond_resched(); + } + + *biop = bio; + return 0; +} + +/** * __blkdev_issue_zeroout - generate number of zero filed write bios * @bdev: blockdev to issue * @sector: start sector @@ -259,6 +308,11 @@ int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, goto out; } + ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask, + biop); + if (ret == 0 || (ret && ret != -EOPNOTSUPP)) + goto out; + ret = __blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, ZERO_PAGE(0), biop); if (ret == 0 || (ret && ret != -EOPNOTSUPP)) @@ -304,8 +358,8 @@ EXPORT_SYMBOL(__blkdev_issue_zeroout); * the discard request fail, if the discard flag is not set, or if * discard_zeroes_data is not supported, this function will resort to * zeroing the blocks manually, thus provisioning (allocating, - * anchoring) them. If the block device supports the WRITE SAME command - * blkdev_issue_zeroout() will use it to optimize the process of + * anchoring) them. If the block device supports WRITE ZEROES or WRITE SAME + * command(s), blkdev_issue_zeroout() will use it to optimize the process of * clearing the block range. Otherwise the zeroing will be performed * using regular WRITE calls. */ |
