diff options
| author | Martin K. Petersen <martin.petersen@oracle.com> | 2012-09-18 12:19:27 -0400 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2012-09-20 14:31:45 +0200 |
| commit | 4363ac7c13a9a4b763c6e8d9fdbfc2468f3b8ca4 (patch) | |
| tree | 010b05699eb9544b9cdfe5e1b3affdaea80132e7 /include/linux/blk_types.h | |
| parent | f31dc1cd490539e2b62a126bc4dc2495b165d772 (diff) | |
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>
Diffstat (limited to 'include/linux/blk_types.h')
| -rw-r--r-- | include/linux/blk_types.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 1b229664f573..cdf11191e645 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -147,6 +147,7 @@ enum rq_flag_bits { __REQ_PRIO, /* boost priority in cfq */ __REQ_DISCARD, /* request to discard sectors */ __REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */ + __REQ_WRITE_SAME, /* write same block many times */ __REQ_NOIDLE, /* don't anticipate more IO after this one */ __REQ_FUA, /* forced unit access */ @@ -185,13 +186,15 @@ enum rq_flag_bits { #define REQ_META (1 << __REQ_META) #define REQ_PRIO (1 << __REQ_PRIO) #define REQ_DISCARD (1 << __REQ_DISCARD) +#define REQ_WRITE_SAME (1 << __REQ_WRITE_SAME) #define REQ_NOIDLE (1 << __REQ_NOIDLE) #define REQ_FAILFAST_MASK \ (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) #define REQ_COMMON_MASK \ (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | \ - REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE) + REQ_DISCARD | REQ_WRITE_SAME | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | \ + REQ_SECURE) #define REQ_CLONE_MASK REQ_COMMON_MASK /* This mask is used for both bio and request merge checking */ |