BLKDEV_ISSUE_ZEROOUT(9)                   Block Devices                   BLKDEV_ISSUE_ZEROOUT(9)



NAME
       blkdev_issue_zeroout - zero-fill a block range

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

ARGUMENTS
       bdev
           blockdev to write

       sector
           start sector

       nr_sects
           number of sectors to write

       gfp_mask
           memory allocation flags (for bio_alloc)

       discard
           whether to discard the block range

DESCRIPTION
       Zero-fill a block range. If the discard flag is set and the block device guarantees that
       subsequent READ operations to the block range in question will return zeroes, the blocks
       will be discarded. Should 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 clearing
       the block range. Otherwise the zeroing will be performed using regular WRITE calls.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                   BLKDEV_ISSUE_ZEROOUT(9)