For block devices, the SCSI target drivers implements UNMAP as calls to
blkdev_issue_discard, which does not guarantee zeroing just because
Write Zeroes is supported.
Note that this does not affect the file backed path which uses
fallocate to punch holes.
Fixes: ed4fe0e4eb07 ("target/iblock: Convert WRITE_SAME to blkdev_issue_zeroout")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
attrib->unmap_granularity = q->limits.discard_granularity / block_size;
attrib->unmap_granularity_alignment = q->limits.discard_alignment /
block_size;
- attrib->unmap_zeroes_data = !!(q->limits.max_write_zeroes_sectors);
return true;
}
EXPORT_SYMBOL(target_configure_unmap_from_queue);