/* * blk.h * * Note: pared down for USENIX example source code */ #ifndef _BLK_H #define _BLK_H #include #include #include /* * NR_REQUEST is the number of entries in the request-queue. * NOTE that writes may use only the low 2/3 of these: reads * take precedence. */ #define NR_REQUEST 64 /* * This is used in the elevator algorithm. We don't prioritise reads * over writes any more --- although reads are more time-critical than * writes, by treating them equally we increase filesystem throughput. * This turns out to give better overall performance. -- sct */ #define IN_ORDER(s1,s2) \ ((s1)->rq_dev < (s2)->rq_dev || (((s1)->rq_dev == (s2)->rq_dev && \ (s1)->sector < (s2)->sector))) /* * These will have to be changed to be aware of different buffer * sizes etc.. It actually needs a major cleanup. */ #if defined(IDE_DRIVER) || defined(MD_DRIVER) #define SECTOR_MASK ((BLOCK_SIZE >> 9) - 1) #else #define SECTOR_MASK (blksize_size[MAJOR_NR] && \ blksize_size[MAJOR_NR][MINOR(CURRENT->rq_dev)] ? \ ((blksize_size[MAJOR_NR][MINOR(CURRENT->rq_dev)] >> 9) - 1) : \ ((BLOCK_SIZE >> 9) - 1)) #endif /* IDE_DRIVER */ #define SUBSECTOR(block) (CURRENT->current_nr_sectors > 0) #ifdef CONFIG_BLK_DEV_HD extern int hd_init(void); #endif #ifdef CONFIG_BLK_DEV_IDE extern int ide_init(void); #endif #ifdef CONFIG_BLK_DEV_XD extern int xd_init(void); #endif #ifdef CONFIG_BLK_DEV_LOOP extern int loop_init(void); #endif #ifdef CONFIG_BLK_DEV_MD extern int md_init(void); #endif CONFIG_BLK_DEV_MD extern void set_device_ro(kdev_t dev,int flag); void add_blkdev_randomness(int major); extern int floppy_init(void); extern void rd_load(void); extern int rd_init(void); extern int rd_doload; /* 1 = load ramdisk, 0 = don't load */ extern int rd_prompt; /* 1 = prompt for ramdisk, 0 = don't prompt */ extern int rd_image_start; /* starting block # of image */ #if defined(MAJOR_NR) || defined(IDE_DRIVER) /* * Add entries as needed. */ #ifdef IDE_DRIVER #define DEVICE_NR(device) (MINOR(device) >> PARTN_BITS) #define DEVICE_ON(device) /* nothing */ #define DEVICE_OFF(device) /* nothing */ #elif (MAJOR_NR == RAMDISK_MAJOR) /* ram disk */ #define DEVICE_NAME "ramdisk" #define DEVICE_REQUEST rd_request #define DEVICE_NR(device) (MINOR(device)) #define DEVICE_ON(device) #define DEVICE_OFF(device) #define DEVICE_NO_RANDOM #elif (MAJOR_NR == FLOPPY_MAJOR) static void floppy_off(unsigned int nr); #define DEVICE_NAME "floppy" #define DEVICE_INTR do_floppy #define DEVICE_REQUEST do_fd_request #define DEVICE_NR(device) ( (MINOR(device) & 3) | \ ((MINOR(device) & 0x80 ) >> 5 )) #define DEVICE_ON(device) #define DEVICE_OFF(device) floppy_off(DEVICE_NR(device)) #elif (MAJOR_NR == HD_MAJOR) /* harddisk: timeout is 6 seconds.. */ #define DEVICE_NAME "harddisk" #define DEVICE_INTR do_hd #define DEVICE_TIMEOUT HD_TIMER #define TIMEOUT_VALUE (6*HZ) #define DEVICE_REQUEST do_hd_request #define DEVICE_NR(device) (MINOR(device)>>6) #define DEVICE_ON(device) #define DEVICE_OFF(device) #elif (MAJOR_NR == SCSI_DISK_MAJOR) #define DEVICE_NAME "scsidisk" #define DEVICE_INTR do_sd #define TIMEOUT_VALUE (2*HZ) #define DEVICE_REQUEST do_sd_request #define DEVICE_NR(device) (MINOR(device) >> 4) #define DEVICE_ON(device) #define DEVICE_OFF(device) #elif (MAJOR_NR == SCSI_TAPE_MAJOR) #define DEVICE_NAME "scsitape" #define DEVICE_INTR do_st #define DEVICE_NR(device) (MINOR(device) & 0x7f) #define DEVICE_ON(device) #define DEVICE_OFF(device) #elif (MAJOR_NR == SCSI_CDROM_MAJOR) #define DEVICE_NAME "CD-ROM" #define DEVICE_INTR do_sr #define DEVICE_REQUEST do_sr_request #define DEVICE_NR(device) (MINOR(device)) #define DEVICE_ON(device) #define DEVICE_OFF(device) #elif (MAJOR_NR == XT_DISK_MAJOR) #define DEVICE_NAME "xt disk" #define DEVICE_REQUEST do_xd_request #define DEVICE_NR(device) (MINOR(device) >> 6) #define DEVICE_ON(device) #define DEVICE_OFF(device) #endif /* MAJOR_NR == whatever */ #if (MAJOR_NR != SCSI_TAPE_MAJOR) #if !defined(IDE_DRIVER) #ifndef CURRENT #define CURRENT (blk_dev[MAJOR_NR].current_request) #endif #define CURRENT_DEV DEVICE_NR(CURRENT->rq_dev) #ifdef DEVICE_INTR static void (*DEVICE_INTR)(void) = NULL; #endif #ifdef DEVICE_TIMEOUT #define SET_TIMER \ ((timer_table[DEVICE_TIMEOUT].expires = jiffies + TIMEOUT_VALUE), \ (timer_active |= 1<rq_dev) != MAJOR_NR) \ panic(DEVICE_NAME ": request list destroyed"); \ if (CURRENT->bh) { \ if (!buffer_locked(CURRENT->bh)) \ panic(DEVICE_NAME ": block not locked"); \ } #endif /* !defined(IDE_DRIVER) */ /* end_request() - SCSI devices have their own version */ /* - IDE drivers have their own copy too */ #if ! SCSI_BLK_MAJOR(MAJOR_NR) /* shared copy for IDE modules */ #if defined(IDE_DRIVER) && !defined(_IDE_C) void ide_end_request(byte uptodate, ide_hwgroup_t *hwgroup); #else #ifdef IDE_DRIVER void ide_end_request(byte uptodate, ide_hwgroup_t *hwgroup) { struct request *req = hwgroup->rq; #else static void end_request(int uptodate) { struct request *req = CURRENT; #endif /* IDE_DRIVER */ struct buffer_head * bh; req->errors = 0; if (!uptodate) { printk("end_request: I/O error, dev %s, sector %lu\n", kdevname(req->rq_dev), req->sector); req->nr_sectors--; req->nr_sectors &= ~SECTOR_MASK; req->sector += (BLOCK_SIZE / 512); req->sector &= ~SECTOR_MASK; } if ((bh = req->bh) != NULL) { req->bh = bh->b_reqnext; bh->b_reqnext = NULL; mark_buffer_uptodate(bh, uptodate); unlock_buffer(bh); if ((bh = req->bh) != NULL) { req->current_nr_sectors = bh->b_size >> 9; if (req->nr_sectors < req->current_nr_sectors) { req->nr_sectors = req->current_nr_sectors; printk("end_request: buffer-list destroyed\n"); } req->buffer = bh->b_data; return; } } #ifndef DEVICE_NO_RANDOM add_blkdev_randomness(MAJOR(req->rq_dev)); #endif #ifdef IDE_DRIVER blk_dev[MAJOR(req->rq_dev)].current_request = req->next; hwgroup->rq = NULL; #else DEVICE_OFF(req->rq_dev); CURRENT = req->next; #endif /* IDE_DRIVER */ if (req->sem != NULL) up(req->sem); req->rq_status = RQ_INACTIVE; wake_up(&wait_for_request); } #endif /* defined(IDE_DRIVER) && !defined(_IDE_C) */ #endif /* ! SCSI_BLK_MAJOR(MAJOR_NR) */ #endif /* (MAJOR_NR != SCSI_TAPE_MAJOR) */ #endif /* defined(MAJOR_NR) || defined(IDE_DRIVER) */ #endif /* _BLK_H */