tree 010b05699eb9544b9cdfe5e1b3affdaea80132e7
parent f31dc1cd490539e2b62a126bc4dc2495b165d772
author Martin K. Petersen <martin.petersen@oracle.com> 1347985167 -0400
committer Jens Axboe <axboe@kernel.dk> 1348144305 +0200

block: Implement support for WRITE SAME

The WRITE SAME command supported on some SCSI devices allows the same
block to be efficiently replicated throughout a block range. Only a
single logical block is transferred from the host and the storage device
writes the same data to all blocks described by the I/O.

This patch implements support for WRITE SAME in the block layer. The
blkdev_issue_write_same() function can be used by filesystems and block
drivers to replicate a buffer across a block range. This can be used to
efficiently initialize software RAID devices, etc.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>