block, drivers: add REQ_OP_FLUSH operation
This adds a REQ_OP_FLUSH operation that is sent to request_fn
based drivers by the block layer's flush code, instead of
sending requests with the request->cmd_flags REQ_FLUSH bit set.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 23c1ab2..32d8752 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -249,9 +249,10 @@
REQ_OP_WRITE,
REQ_OP_DISCARD, /* request to discard sectors */
REQ_OP_WRITE_SAME, /* write same block many times */
+ REQ_OP_FLUSH, /* request for cache flush */
};
-#define REQ_OP_BITS 2
+#define REQ_OP_BITS 3
typedef unsigned int blk_qc_t;
#define BLK_QC_T_NONE -1U
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 78ae3db..0c9f879 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -666,6 +666,9 @@
if (rq->cmd_type != REQ_TYPE_FS)
return false;
+ if (req_op(rq) == REQ_OP_FLUSH)
+ return false;
+
if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
return false;