Loading...
#ifndef _LINUX_BLKDEV_H #define _LINUX_BLKDEV_H #include <linux/major.h> #include <linux/sched.h> #include <linux/genhd.h> #include <linux/tqueue.h> /* * Ok, this is an expanded form so that we can use the same * request for paging requests when that is implemented. In * paging, 'bh' is NULL, and the semaphore is used to wait * for read/write completion. */ struct request { volatile int rq_status; /* should split this into a few status bits */ #define RQ_INACTIVE (-1) #define RQ_ACTIVE 1 #define RQ_SCSI_BUSY 0xffff #define RQ_SCSI_DONE 0xfffe #define RQ_SCSI_DISCONNECTING 0xffe0 kdev_t rq_dev; int cmd; /* READ or WRITE */ int errors; unsigned long sector; unsigned long nr_sectors; unsigned long nr_segments; unsigned long current_nr_sectors; char * buffer; struct semaphore * sem; struct buffer_head * bh; struct buffer_head * bhtail; struct request * next; }; typedef void (request_fn_proc) (void); typedef struct request ** (queue_proc) (kdev_t dev); struct blk_dev_struct { request_fn_proc *request_fn; /* * queue_proc has to be atomic */ queue_proc *queue; void *data; struct request *current_request; struct request plug; struct tq_struct plug_tq; }; struct sec_size { unsigned block_size; unsigned block_size_bits; }; extern struct sec_size * blk_sec[MAX_BLKDEV]; extern struct blk_dev_struct blk_dev[MAX_BLKDEV]; extern struct wait_queue * wait_for_request; extern void resetup_one_dev(struct gendisk *dev, int drive); extern void unplug_device(void * data); extern void make_request(int major,int rw, struct buffer_head * bh); /* md needs this function to remap requests */ extern int md_map (int minor, kdev_t *rdev, unsigned long *rsector, unsigned long size); extern int md_make_request (int minor, int rw, struct buffer_head * bh); extern int md_error (kdev_t mddev, kdev_t rdev); extern int * blk_size[MAX_BLKDEV]; extern int * blksize_size[MAX_BLKDEV]; extern int * hardsect_size[MAX_BLKDEV]; extern int * max_readahead[MAX_BLKDEV]; extern int * max_sectors[MAX_BLKDEV]; extern int * max_segments[MAX_BLKDEV]; #define MAX_SECTORS 128 #define MAX_SEGMENTS MAX_SECTORS #define PageAlignSize(size) (((size) + PAGE_SIZE -1) & PAGE_MASK) #if 0 /* small readahead */ #define MAX_READAHEAD PageAlignSize(4096*7) #define MIN_READAHEAD PageAlignSize(4096*2) #else /* large readahead */ #define MAX_READAHEAD PageAlignSize(4096*31) #define MIN_READAHEAD PageAlignSize(4096*3) #endif #endif |