struct request_queue;
struct elevator_queue;
-typedef struct elevator_queue elevator_t;
struct request_pm_state;
struct blk_trace;
struct request;
typedef void (rq_end_io_fn)(struct request *, int);
struct request_list {
+ /*
+ * count[], starved[], and wait[] are indexed by
+ * BLK_RW_SYNC/BLK_RW_ASYNC
+ */
int count[2];
int starved[2];
int elvpriv;
REQ_TYPE_ATA_PC,
};
+enum {
+ BLK_RW_ASYNC = 0,
+ BLK_RW_SYNC = 1,
+};
+
/*
* 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
__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_RW_SYNC, /* request is sync (sync write or read) */
__REQ_ALLOCED, /* request came from our alloc pool */
__REQ_RW_META, /* metadata io request */
__REQ_COPY_USER, /* contains copies of user pages */
__REQ_INTEGRITY, /* integrity metadata has been remapped */
+ __REQ_NOIDLE, /* Don't anticipate more IO after this one */
+ __REQ_IO_STAT, /* account I/O stat */
__REQ_NR_BITS, /* stops here */
};
#define REQ_RW_META (1 << __REQ_RW_META)
#define REQ_COPY_USER (1 << __REQ_COPY_USER)
#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
+#define REQ_NOIDLE (1 << __REQ_NOIDLE)
+#define REQ_IO_STAT (1 << __REQ_IO_STAT)
#define BLK_MAX_CDB 16
enum rq_cmd_type_bits cmd_type;
unsigned long atomic_flags;
- /* Maintain bio traversal state for part by part I/O submission.
- * hard_* are block layer internals, no driver should touch them!
- */
-
- sector_t sector; /* next sector to submit */
- sector_t hard_sector; /* next sector to complete */
- unsigned long nr_sectors; /* no. of sectors left to submit */
- unsigned long hard_nr_sectors; /* no. of sectors left to complete */
- /* no. of sectors left to submit in the current segment */
- unsigned int current_nr_sectors;
-
- /* no. of sectors left to complete in the current segment */
- unsigned int hard_cur_sectors;
+ /* the following two fields are internal, NEVER access directly */
+ sector_t __sector; /* sector cursor */
+ unsigned int __data_len; /* total data len */
struct bio *bio;
struct bio *biotail;
unsigned short ioprio;
- void *special;
- char *buffer;
+ void *special; /* opaque pointer available for LLD use */
+ char *buffer; /* kaddr of the current segment if available */
int tag;
int errors;
unsigned char __cmd[BLK_MAX_CDB];
unsigned char *cmd;
- unsigned int data_len;
unsigned int extra_len; /* length of alignment and padding */
unsigned int sense_len;
- void *data;
+ unsigned int resid_len; /* residual count */
void *sense;
unsigned long deadline;
*/
struct list_head queue_head;
struct request *last_merge;
- elevator_t *elevator;
+ struct elevator_queue *elevator;
/*
* the queue request freelist, one for reads and one for writes
#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
-#define QUEUE_FLAG_READFULL 3 /* read queue has been filled */
-#define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */
+#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
+#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
#define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
+#define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
+
+#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
+ (1 << QUEUE_FLAG_CLUSTER) | \
+ (1 << QUEUE_FLAG_STACKABLE))
static inline int queue_is_locked(struct request_queue *q)
{
#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
+#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
#define blk_queue_flushing(q) ((q)->ordseq)
#define blk_queue_stackable(q) \
test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
blk_failfast_transport(rq) || \
blk_failfast_driver(rq))
#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
+#define blk_rq_io_stat(rq) ((rq)->cmd_flags & REQ_IO_STAT)
#define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
#define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
-#define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
/* rq->queuelist of dequeued request must be list_empty() */
#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
#define rq_data_dir(rq) ((rq)->cmd_flags & 1)
/*
- * We regard a request as sync, if it's a READ or a SYNC write.
+ * We regard a request as sync, if either a read or a sync write
*/
-#define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)
+static inline bool rw_is_sync(unsigned int rw_flags)
+{
+ return !(rw_flags & REQ_RW) || (rw_flags & REQ_RW_SYNC);
+}
+
+static inline bool rq_is_sync(struct request *rq)
+{
+ return rw_is_sync(rq->cmd_flags);
+}
+
#define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
+#define rq_noidle(rq) ((rq)->cmd_flags & REQ_NOIDLE)
-static inline int blk_queue_full(struct request_queue *q, int rw)
+static inline int blk_queue_full(struct request_queue *q, int sync)
{
- if (rw == READ)
- return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
- return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
+ if (sync)
+ return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
+ return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
}
-static inline void blk_set_queue_full(struct request_queue *q, int rw)
+static inline void blk_set_queue_full(struct request_queue *q, int sync)
{
- if (rw == READ)
- queue_flag_set(QUEUE_FLAG_READFULL, q);
+ if (sync)
+ queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
else
- queue_flag_set(QUEUE_FLAG_WRITEFULL, q);
+ queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
}
-static inline void blk_clear_queue_full(struct request_queue *q, int rw)
+static inline void blk_clear_queue_full(struct request_queue *q, int sync)
{
- if (rw == READ)
- queue_flag_clear(QUEUE_FLAG_READFULL, q);
+ if (sync)
+ queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
else
- queue_flag_clear(QUEUE_FLAG_WRITEFULL, q);
+ queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
}
struct page **pages;
int page_order;
int nr_entries;
+ unsigned long offset;
+ int null_mapped;
};
struct req_iterator {
};
/* This should not be used directly - use rq_for_each_segment */
+#define for_each_bio(_bio) \
+ for (; _bio; _bio = _bio->bi_next)
#define __rq_for_each_bio(_bio, rq) \
if ((rq->bio)) \
for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
extern void __blk_stop_queue(struct request_queue *q);
extern void __blk_run_queue(struct request_queue *);
extern void blk_run_queue(struct request_queue *);
-extern void blk_start_queueing(struct request_queue *);
extern int blk_rq_map_user(struct request_queue *, struct request *,
struct rq_map_data *, void __user *, unsigned long,
gfp_t);
blk_run_backing_dev(mapping->backing_dev_info, NULL);
}
-extern void blkdev_dequeue_request(struct request *req);
+/*
+ * blk_rq_pos() : the current sector
+ * blk_rq_bytes() : bytes left in the entire request
+ * blk_rq_cur_bytes() : bytes left in the current segment
+ * blk_rq_sectors() : sectors left in the entire request
+ * blk_rq_cur_sectors() : sectors left in the current segment
+ */
+static inline sector_t blk_rq_pos(const struct request *rq)
+{
+ return rq->__sector;
+}
+
+static inline unsigned int blk_rq_bytes(const struct request *rq)
+{
+ return rq->__data_len;
+}
+
+static inline int blk_rq_cur_bytes(const struct request *rq)
+{
+ return rq->bio ? bio_cur_bytes(rq->bio) : 0;
+}
+
+static inline unsigned int blk_rq_sectors(const struct request *rq)
+{
+ return blk_rq_bytes(rq) >> 9;
+}
+
+static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
+{
+ return blk_rq_cur_bytes(rq) >> 9;
+}
+
+/*
+ * Request issue related functions.
+ */
+extern struct request *blk_peek_request(struct request_queue *q);
+extern void blk_start_request(struct request *rq);
+extern struct request *blk_fetch_request(struct request_queue *q);
/*
- * blk_end_request() and friends.
- * __blk_end_request() and end_request() must be called with
- * the request queue spinlock acquired.
+ * Request completion related functions.
+ *
+ * blk_update_request() completes given number of bytes and updates
+ * the request without completing it.
+ *
+ * blk_end_request() and friends. __blk_end_request() must be called
+ * with the request queue spinlock acquired.
*
* Several drivers define their own end_request and call
* blk_end_request() for parts of the original function.
* This prevents code duplication in drivers.
*/
-extern int blk_end_request(struct request *rq, int error,
- unsigned int nr_bytes);
-extern int __blk_end_request(struct request *rq, int error,
- unsigned int nr_bytes);
-extern int blk_end_bidi_request(struct request *rq, int error,
- unsigned int nr_bytes, unsigned int bidi_bytes);
-extern void end_request(struct request *, int);
-extern int blk_end_request_callback(struct request *rq, int error,
- unsigned int nr_bytes,
- int (drv_callback)(struct request *));
+extern bool blk_update_request(struct request *rq, int error,
+ unsigned int nr_bytes);
+extern bool blk_end_bidi_request(struct request *rq, int error,
+ unsigned int nr_bytes,
+ unsigned int bidi_bytes);
+extern bool __blk_end_bidi_request(struct request *rq, int error,
+ unsigned int nr_bytes,
+ unsigned int bidi_bytes);
+
+/**
+ * blk_end_request - Helper function for drivers to complete the request.
+ * @rq: the request being processed
+ * @error: %0 for success, < %0 for error
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ * Ends I/O on a number of bytes attached to @rq.
+ * If @rq has leftover, sets it up for the next range of segments.
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ **/
+static inline bool blk_end_request(struct request *rq, int error,
+ unsigned int nr_bytes)
+{
+ return blk_end_bidi_request(rq, error, nr_bytes, 0);
+}
+
+/**
+ * blk_end_request_all - Helper function for drives to finish the request.
+ * @rq: the request to finish
+ * @err: %0 for success, < %0 for error
+ *
+ * Description:
+ * Completely finish @rq.
+ */
+static inline void blk_end_request_all(struct request *rq, int error)
+{
+ bool pending;
+
+ pending = blk_end_request(rq, error, blk_rq_bytes(rq));
+ BUG_ON(pending);
+}
+
+/**
+ * blk_end_request_cur - Helper function to finish the current request chunk.
+ * @rq: the request to finish the current chunk for
+ * @err: %0 for success, < %0 for error
+ *
+ * Description:
+ * Complete the current consecutively mapped chunk from @rq.
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ */
+static inline bool blk_end_request_cur(struct request *rq, int error)
+{
+ return blk_end_request(rq, error, blk_rq_cur_bytes(rq));
+}
+
+/**
+ * __blk_end_request - Helper function for drivers to complete the request.
+ * @rq: the request being processed
+ * @error: %0 for success, < %0 for error
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ * Must be called with queue lock held unlike blk_end_request().
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ **/
+static inline bool __blk_end_request(struct request *rq, int error,
+ unsigned int nr_bytes)
+{
+ return __blk_end_bidi_request(rq, error, nr_bytes, 0);
+}
+
+/**
+ * __blk_end_request_all - Helper function for drives to finish the request.
+ * @rq: the request to finish
+ * @err: %0 for success, < %0 for error
+ *
+ * Description:
+ * Completely finish @rq. Must be called with queue lock held.
+ */
+static inline void __blk_end_request_all(struct request *rq, int error)
+{
+ bool pending;
+
+ pending = __blk_end_request(rq, error, blk_rq_bytes(rq));
+ BUG_ON(pending);
+}
+
+/**
+ * __blk_end_request_cur - Helper function to finish the current request chunk.
+ * @rq: the request to finish the current chunk for
+ * @err: %0 for success, < %0 for error
+ *
+ * Description:
+ * Complete the current consecutively mapped chunk from @rq. Must
+ * be called with queue lock held.
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ */
+static inline bool __blk_end_request_cur(struct request *rq, int error)
+{
+ return __blk_end_request(rq, error, blk_rq_cur_bytes(rq));
+}
+
extern void blk_complete_request(struct request *);
extern void __blk_complete_request(struct request *);
extern void blk_abort_request(struct request *);
extern void blk_abort_queue(struct request_queue *);
-extern void blk_update_request(struct request *rq, int error,
- unsigned int nr_bytes);
-
-/*
- * blk_end_request() takes bytes instead of sectors as a complete size.
- * blk_rq_bytes() returns bytes left to complete in the entire request.
- * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
- */
-extern unsigned int blk_rq_bytes(struct request *rq);
-extern unsigned int blk_rq_cur_bytes(struct request *rq);
/*
* Access functions for manipulating queue properties
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff