Home
last modified time | relevance | path

Searched hist:"70 d6c400acc386ea910c77318688541fc32e7ce8" (Results 1 – 2 of 2) sorted by relevance

/linux/drivers/md/
H A Ddm-kcopyd.cdiff 70d6c400acc386ea910c77318688541fc32e7ce8 Fri Dec 21 21:23:37 CET 2012 Mike Snitzer <snitzer@redhat.com> dm kcopyd: add WRITE SAME support to dm_kcopyd_zero

Add WRITE SAME support to dm-io and make it accessible to
dm_kcopyd_zero(). dm_kcopyd_zero() provides an asynchronous interface
whereas the blkdev_issue_write_same() interface is synchronous.

WRITE SAME is a SCSI command that can be leveraged for more efficient
zeroing of a specified logical extent of a device which supports it.
Only a single zeroed logical block is transfered to the target for each
WRITE SAME and the target then writes that same block across the
specified extent.

The dm thin target uses this.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
H A Ddm-io.cdiff 70d6c400acc386ea910c77318688541fc32e7ce8 Fri Dec 21 21:23:37 CET 2012 Mike Snitzer <snitzer@redhat.com> dm kcopyd: add WRITE SAME support to dm_kcopyd_zero

Add WRITE SAME support to dm-io and make it accessible to
dm_kcopyd_zero(). dm_kcopyd_zero() provides an asynchronous interface
whereas the blkdev_issue_write_same() interface is synchronous.

WRITE SAME is a SCSI command that can be leveraged for more efficient
zeroing of a specified logical extent of a device which supports it.
Only a single zeroed logical block is transfered to the target for each
WRITE SAME and the target then writes that same block across the
specified extent.

The dm thin target uses this.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>