blkdev_issue_zeroout (9)

int blkdev_issue_zeroout(struct block_device * bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask);

bdev

blockdev to write

sector

start sector

nr_sects

number of sectors to write

gfp_mask

memory allocation flags (for bio_alloc)

Generate and issue number of bios with zerofiled pages.