From 4363ac7c13a9a4b763c6e8d9fdbfc2468f3b8ca4 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Tue, 18 Sep 2012 12:19:27 -0400 Subject: 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 Acked-by: Mike Snitzer Signed-off-by: Jens Axboe --- include/linux/bio.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/bio.h') diff --git a/include/linux/bio.h b/include/linux/bio.h index e54305cacc98..820e7aaad4fd 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -399,6 +399,9 @@ static inline bool bio_is_rw(struct bio *bio) if (!bio_has_data(bio)) return false; + if (bio->bi_rw & REQ_WRITE_SAME) + return false; + return true; } -- cgit v1.2.3