[PATCH] Split struct request ->flags into two parts
Right now ->flags is a bit of a mess: some are request types, and
others are just modifiers. Clean this up by splitting it into
->cmd_type and ->cmd_flags. This allows introduction of generic
Linux block message types, useful for sending generic Linux commands
to block devices.
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index cfde8b3..b2a412c 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -120,6 +120,86 @@
wait_queue_head_t wait[2];
};
+/*
+ * 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,
+};
+
+/*
+ * 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_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 BLK_MAX_CDB 16
/*
@@ -129,7 +209,8 @@
struct list_head queuelist;
struct list_head donelist;
- unsigned long flags; /* see REQ_ bits below */
+ unsigned int cmd_flags;
+ enum rq_cmd_type_bits cmd_type;
/* Maintain bio traversal state for part by part I/O submission.
* hard_* are block layer internals, no driver should touch them!
@@ -202,73 +283,7 @@
};
/*
- * 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_CMD, /* is a regular fs rw request */
- __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 */
- /*
- * for ATA/ATAPI devices
- */
- __REQ_PC, /* packet command (special) */
- __REQ_BLOCK_PC, /* queued down pc from block layer */
- __REQ_SENSE, /* sense retrival */
-
- __REQ_FAILED, /* set if the request failed */
- __REQ_QUIET, /* don't worry about errors */
- __REQ_SPECIAL, /* driver suplied command */
- __REQ_DRIVE_CMD,
- __REQ_DRIVE_TASK,
- __REQ_DRIVE_TASKFILE,
- __REQ_PREEMPT, /* set for "ide_preempt" requests */
- __REQ_PM_SUSPEND, /* suspend request */
- __REQ_PM_RESUME, /* resume request */
- __REQ_PM_SHUTDOWN, /* shutdown request */
- __REQ_ORDERED_COLOR, /* is before or after barrier */
- __REQ_RW_SYNC, /* request is sync (O_DIRECT) */
- __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_CMD (1 << __REQ_CMD)
-#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_PC (1 << __REQ_PC)
-#define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC)
-#define REQ_SENSE (1 << __REQ_SENSE)
-#define REQ_FAILED (1 << __REQ_FAILED)
-#define REQ_QUIET (1 << __REQ_QUIET)
-#define REQ_SPECIAL (1 << __REQ_SPECIAL)
-#define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD)
-#define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK)
-#define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE)
-#define REQ_PREEMPT (1 << __REQ_PREEMPT)
-#define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND)
-#define REQ_PM_RESUME (1 << __REQ_PM_RESUME)
-#define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN)
-#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
-#define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
-
-/*
- * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME
+ * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
* requests. Some step values could eventually be made generic.
*/
struct request_pm_state
@@ -490,25 +505,28 @@
#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
#define blk_queue_flushing(q) ((q)->ordseq)
-#define blk_fs_request(rq) ((rq)->flags & REQ_CMD)
-#define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC)
-#define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST)
-#define blk_rq_started(rq) ((rq)->flags & REQ_STARTED)
+#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
+#define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
+#define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
+#define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
+
+#define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST)
+#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
#define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
-#define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND)
-#define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME)
+#define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
+#define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
#define blk_pm_request(rq) \
- ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))
+ (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
-#define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED)
-#define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER)
-#define blk_fua_rq(rq) ((rq)->flags & REQ_FUA)
+#define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
+#define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
+#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
-#define rq_data_dir(rq) ((rq)->flags & 1)
+#define rq_data_dir(rq) ((rq)->cmd_flags & 1)
static inline int blk_queue_full(struct request_queue *q, int rw)
{
@@ -541,7 +559,7 @@
#define RQ_NOMERGE_FLAGS \
(REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
#define rq_mergeable(rq) \
- (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
+ (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
/*
* noop, requests are automagically marked as active/inactive by I/O
@@ -737,7 +755,7 @@
*/
#define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
#define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
-#define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED)
+#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
extern int blk_queue_start_tag(request_queue_t *, struct request *);
extern struct request *blk_queue_find_tag(request_queue_t *, int);
extern void blk_queue_end_tag(request_queue_t *, struct request *);