diff options
Diffstat (limited to 'include/linux/blkdev.h')
| -rw-r--r-- | include/linux/blkdev.h | 43 |
1 files changed, 36 insertions, 7 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 6eed225b6..c035f1327 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -5,6 +5,10 @@ #include <linux/sched.h> #include <linux/genhd.h> #include <linux/tqueue.h> +#include <linux/list.h> + +struct request_queue; +typedef struct request_queue request_queue_t; /* * Ok, this is an expanded form so that we can use the same @@ -13,6 +17,9 @@ * for read/write completion. */ struct request { + struct list_head queue; + int elevator_sequence; + volatile int rq_status; /* should split this into a few status bits */ #define RQ_INACTIVE (-1) #define RQ_ACTIVE 1 @@ -33,27 +40,42 @@ struct request { struct semaphore * sem; struct buffer_head * bh; struct buffer_head * bhtail; - struct request * next; + request_queue_t * q; }; -typedef struct request_queue request_queue_t; typedef int (merge_request_fn) (request_queue_t *q, struct request *req, - struct buffer_head *bh); + struct buffer_head *bh, + int); typedef int (merge_requests_fn) (request_queue_t *q, struct request *req, - struct request *req2); + struct request *req2, + int); typedef void (request_fn_proc) (request_queue_t *q); typedef request_queue_t * (queue_proc) (kdev_t dev); typedef void (make_request_fn) (int rw, struct buffer_head *bh); typedef void (plug_device_fn) (request_queue_t *q, kdev_t device); typedef void (unplug_device_fn) (void *q); +typedef struct elevator_s +{ + int sequence; + int read_latency; + int write_latency; + int max_bomb_segments; + int read_pendings; +} elevator_t; + struct request_queue { - struct request * current_request; + struct list_head queue_head; + /* together with queue_head for cacheline sharing */ + elevator_t elevator; + unsigned int nr_segments; + request_fn_proc * request_fn; - merge_request_fn * merge_fn; + merge_request_fn * back_merge_fn; + merge_request_fn * front_merge_fn; merge_requests_fn * merge_requests_fn; make_request_fn * make_request_fn; plug_device_fn * plug_device_fn; @@ -107,7 +129,6 @@ extern wait_queue_head_t wait_for_request; extern void grok_partitions(struct gendisk *dev, int drive, unsigned minors, long size); extern void register_disk(struct gendisk *dev, kdev_t first, unsigned minors, struct block_device_operations *ops, long size); extern void generic_unplug_device(void * data); -extern void generic_plug_device (request_queue_t *q, kdev_t dev); extern void generic_make_request(int rw, struct buffer_head * bh); extern request_queue_t * blk_get_queue(kdev_t dev); @@ -142,4 +163,12 @@ extern int * max_segments[MAX_BLKDEV]; #define MAX_READAHEAD 31 #define MIN_READAHEAD 3 +#define ELEVATOR_DEFAULTS ((elevator_t) { 0, NR_REQUEST>>1, NR_REQUEST<<5, 4, 0, }) + +#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queue) +#define blkdev_entry_next_request(entry) blkdev_entry_to_request((entry)->next) +#define blkdev_entry_prev_request(entry) blkdev_entry_to_request((entry)->prev) +#define blkdev_next_request(req) blkdev_entry_to_request((req)->queue.next) +#define blkdev_prev_request(req) blkdev_entry_to_request((req)->queue.prev) + #endif |