1 files changed, 90 insertions, 1 deletions
diff --git a/src/kernel/blk.h b/src/kernel/blk.h
index 2410fe1..2da84bc 100644
--- a/src/kernel/blk.h
+++ b/src/kernel/blk.h
@@ -24,7 +24,96 @@
 
 #include "dnbd3_main.h"
 
-#define REQ_TYPE_SPECIAL REQ_TYPE_DRV_PRIV
+/* define blkdev file system operation type */
+#define DNBD3_REQ_OP_FS           REQ_TYPE_FS
+
+/* define blkdev special operation type */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
+#define DNBD3_REQ_OP_SPECIAL      REQ_OP_DRV_IN
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 2, 0) || \
+	RHEL_CHECK_VERSION(RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(7, 3))
+#define DNBD3_REQ_OP_SPECIAL      REQ_TYPE_DRV_PRIV
+#else
+#define DNBD3_REQ_OP_SPECIAL      REQ_TYPE_SPECIAL
+#endif
+
+/* define blkdev read operation type */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
+#define DNBD3_DEV_READ            REQ_OP_READ
+#else
+#define DNBD3_DEV_READ            DNBD3_REQ_OP_FS
+#endif
+
+/* define blkdev write operation type */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
+#define DNBD3_DEV_WRITE           REQ_OP_WRITE
+#else
+#define DNBD3_DEV_WRITE           DNBD3_REQ_OP_FS
+#endif
+
+/* define command and blkdev operation access macros */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
+#define DNBD3_REQ_FLAG_BITS       REQ_FLAG_BITS
+/* cmd_flags and cmd_type are merged into cmd_flags now */
+/* sanity check to avoid overriding of request bits */
+#if DNBD3_REQ_FLAG_BITS > 24
+#error "Fix CMD bitshift"
+#endif
+/* pack command into cmd_flags field by shifting CMD_* into unused bits of cmd_flags */
+#define dnbd3_cmd_to_priv(req, cmd) \
+	((req)->cmd_flags = DNBD3_REQ_OP_SPECIAL | ((cmd) << DNBD3_REQ_FLAG_BITS))
+#define dnbd3_priv_to_cmd(req) \
+	((req)->cmd_flags >> DNBD3_REQ_FLAG_BITS)
+#define dnbd3_req_op(req) \
+	req_op(req)
+#else
+/* pack command into cmd_type and cmd_flags field separated */
+#define dnbd3_cmd_to_priv(req, cmd) \
+	do { \
+		(req)->cmd_type = DNBD3_REQ_OP_SPECIAL; \
+		(req)->cmd_flags = (cmd); \
+	} while (0)
+#define dnbd3_priv_to_cmd(req) \
+	((req)->cmd_flags)
+#define dnbd3_req_op(req) \
+	((req)->cmd_type)
+#endif
+
+/* define dnbd3_req_read(req) boolean expression */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
+#define dnbd3_req_read(req) \
+	(req_op(req) == DNBD3_DEV_READ)
+#else
+#define dnbd3_req_read(req) \
+	(rq_data_dir(req) == READ)
+#endif
+
+/* define dnbd3_req_write(req) boolean expression */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
+#define dnbd3_req_write(req) \
+	(req_op(req) == DNBD3_DEV_WRITE)
+#else
+#define dnbd3_req_write(req) \
+	(rq_data_dir(req) == WRITE)
+#endif
+
+/* define dnbd3_req_fs(req) boolean expression */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
+#define dnbd3_req_fs(req) \
+	(dnbd3_req_read(req) || dnbd3_req_write(req))
+#else
+#define dnbd3_req_fs(req) \
+	(dnbd3_req_op(req) == DNBD3_REQ_OP_FS)
+#endif
+
+/* define dnbd3_req_special(req) boolean expression */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
+#define dnbd3_req_special(req) \
+	blk_rq_is_private(req)
+#else
+#define dnbd3_req_special(req) \
+	(dnbd3_req_op(req) == DNBD3_REQ_OP_SPECIAL)
+#endif
 
 int dnbd3_blk_add_device(dnbd3_device_t *dev, int minor);