+/*
+ * request command types
+ */
+enum rq_cmd_type_bits {
+ REQ_TYPE_FS = 1, /* fs request */
+ REQ_TYPE_BLOCK_PC, /* scsi command */
+ REQ_TYPE_SENSE, /* sense request */
+ REQ_TYPE_PM_SUSPEND, /* suspend request */
+ REQ_TYPE_PM_RESUME, /* resume request */
+ REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
+ REQ_TYPE_FLUSH, /* flush request */
+ REQ_TYPE_SPECIAL, /* driver defined type */
+ REQ_TYPE_LINUX_BLOCK, /* generic block layer message */
+ /*
+ * for ATA/ATAPI devices. this really doesn't belong here, ide should
+ * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
+ * private REQ_LB opcodes to differentiate what type of request this is
+ */
+ REQ_TYPE_ATA_CMD,
+ REQ_TYPE_ATA_TASK,
+ REQ_TYPE_ATA_TASKFILE,
+ REQ_TYPE_ATA_PC,
+};
+
+/*
+ * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
+ * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
+ * SCSI cdb.
+ *
+ * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
+ * typically to differentiate REQ_TYPE_SPECIAL requests.
+ *
+ */
+enum {
+ /*
+ * just examples for now
+ */
+ REQ_LB_OP_EJECT = 0x40, /* eject request */
+ REQ_LB_OP_FLUSH = 0x41, /* flush device */
+};
+
+/*
+ * request type modified bits. first three bits match BIO_RW* bits, important
+ */
+enum rq_flag_bits {
+ __REQ_RW, /* not set, read. set, write */
+ __REQ_FAILFAST, /* no low level driver retries */
+ __REQ_SORTED, /* elevator knows about this request */
+ __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
+ __REQ_HARDBARRIER, /* may not be passed by drive either */
+ __REQ_FUA, /* forced unit access */
+ __REQ_NOMERGE, /* don't touch this for merging */
+ __REQ_STARTED, /* drive already may have started this one */
+ __REQ_DONTPREP, /* don't call prep for this one */
+ __REQ_QUEUED, /* uses queueing */
+ __REQ_ELVPRIV, /* elevator private data attached */
+ __REQ_FAILED, /* set if the request failed */
+ __REQ_QUIET, /* don't worry about errors */
+ __REQ_PREEMPT, /* set for "ide_preempt" requests */
+ __REQ_ORDERED_COLOR, /* is before or after barrier */
+ __REQ_RW_SYNC, /* request is sync (O_DIRECT) */
+ __REQ_ALLOCED, /* request came from our alloc pool */
+ __REQ_RW_META, /* metadata io request */
+ __REQ_NR_BITS, /* stops here */
+};
+
+#define REQ_RW (1 << __REQ_RW)
+#define REQ_FAILFAST (1 << __REQ_FAILFAST)
+#define REQ_SORTED (1 << __REQ_SORTED)
+#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
+#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
+#define REQ_FUA (1 << __REQ_FUA)
+#define REQ_NOMERGE (1 << __REQ_NOMERGE)
+#define REQ_STARTED (1 << __REQ_STARTED)
+#define REQ_DONTPREP (1 << __REQ_DONTPREP)
+#define REQ_QUEUED (1 << __REQ_QUEUED)
+#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
+#define REQ_FAILED (1 << __REQ_FAILED)
+#define REQ_QUIET (1 << __REQ_QUIET)
+#define REQ_PREEMPT (1 << __REQ_PREEMPT)
+#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
+#define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
+#define REQ_ALLOCED (1 << __REQ_ALLOCED)
+#define REQ_RW_META (1 << __REQ_RW_META)
+