root/drivers/block/blk.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. end_request

   1 #ifndef _BLK_H
   2 #define _BLK_H
   3 
   4 #include <linux/blkdev.h>
   5 #include <linux/locks.h>
   6 
   7 /*
   8  * NR_REQUEST is the number of entries in the request-queue.
   9  * NOTE that writes may use only the low 2/3 of these: reads
  10  * take precedence.
  11  *
  12  * 32 seems to be a reasonable number: enough to get some benefit
  13  * from the elevator-mechanism, but not so much as to lock a lot of
  14  * buffers when they are in the queue. 64 seems to be too many (easily
  15  * long pauses in reading when heavy writing/syncing is going on)
  16  */
  17 #define NR_REQUEST      64
  18 
  19 /*
  20  * This is used in the elevator algorithm: Note that
  21  * reads always go before writes. This is natural: reads
  22  * are much more time-critical than writes.
  23  */
  24 #define IN_ORDER(s1,s2) \
  25 ((s1)->cmd < (s2)->cmd || ((s1)->cmd == (s2)->cmd && \
  26 ((s1)->dev < (s2)->dev || (((s1)->dev == (s2)->dev && \
  27 (s1)->sector < (s2)->sector)))))
  28 
  29 /*
  30  * These will have to be changed to be aware of different buffer
  31  * sizes etc.. It actually needs a major cleanup.
  32  */
  33 #define SECTOR_MASK (blksize_size[MAJOR_NR] &&     \
  34         blksize_size[MAJOR_NR][MINOR(CURRENT->dev)] ? \
  35         ((blksize_size[MAJOR_NR][MINOR(CURRENT->dev)] >> 9) - 1) :  \
  36         ((BLOCK_SIZE >> 9)  -  1))
  37 
  38 #define SUBSECTOR(block) (CURRENT->current_nr_sectors > 0)
  39 
  40 extern unsigned long hd_init(unsigned long mem_start, unsigned long mem_end);
  41 extern unsigned long cdu31a_init(unsigned long mem_start, unsigned long mem_end);
  42 extern unsigned long mcd_init(unsigned long mem_start, unsigned long mem_end);
  43 #ifdef CONFIG_SBPCD
  44 extern unsigned long sbpcd_init(unsigned long, unsigned long);
  45 #endif CONFIG_SBPCD
  46 extern void set_device_ro(int dev,int flag);
  47 
  48 extern void floppy_init(void);
  49 #ifdef FD_MODULE
  50 static
  51 #else
  52 extern
  53 #endif
  54 int new_floppy_init(void);
  55 extern void rd_load(void);
  56 extern long rd_init(long mem_start, int length);
  57 extern int ramdisk_size;
  58 
  59 extern unsigned long xd_init(unsigned long mem_start, unsigned long mem_end);
  60 
  61 #define RO_IOCTLS(dev,where) \
  62   case BLKROSET: if (!suser()) return -EACCES; \
  63                  set_device_ro((dev),get_fs_long((long *) (where))); return 0; \
  64   case BLKROGET: { int __err = verify_area(VERIFY_WRITE, (void *) (where), sizeof(long)); \
  65                    if (!__err) put_fs_long(0!=is_read_only(dev),(long *) (where)); return __err; }
  66                  
  67 #ifdef MAJOR_NR
  68 
  69 /*
  70  * Add entries as needed. Currently the only block devices
  71  * supported are hard-disks and floppies.
  72  */
  73 
  74 #if (MAJOR_NR == MEM_MAJOR)
  75 
  76 /* ram disk */
  77 #define DEVICE_NAME "ramdisk"
  78 #define DEVICE_REQUEST do_rd_request
  79 #define DEVICE_NR(device) ((device) & 7)
  80 #define DEVICE_ON(device) 
  81 #define DEVICE_OFF(device)
  82 
  83 #elif (MAJOR_NR == FLOPPY_MAJOR)
  84 
  85 static void floppy_off(unsigned int nr);
  86 
  87 #define DEVICE_NAME "floppy"
  88 #define DEVICE_INTR do_floppy
  89 #define DEVICE_REQUEST do_fd_request
  90 #define DEVICE_NR(device) ( ((device) & 3) | (((device) & 0x80 ) >> 5 ))
  91 #define DEVICE_ON(device)
  92 #define DEVICE_OFF(device) floppy_off(DEVICE_NR(device))
  93 
  94 #elif (MAJOR_NR == HD_MAJOR)
  95 
  96 /* harddisk: timeout is 6 seconds.. */
  97 #define DEVICE_NAME "harddisk"
  98 #define DEVICE_INTR do_hd
  99 #define DEVICE_TIMEOUT HD_TIMER
 100 #define TIMEOUT_VALUE 600
 101 #define DEVICE_REQUEST do_hd_request
 102 #define DEVICE_NR(device) (MINOR(device)>>6)
 103 #define DEVICE_ON(device)
 104 #define DEVICE_OFF(device)
 105 
 106 #elif (MAJOR_NR == SCSI_DISK_MAJOR)
 107 
 108 #define DEVICE_NAME "scsidisk"
 109 #define DEVICE_INTR do_sd  
 110 #define TIMEOUT_VALUE 200
 111 #define DEVICE_REQUEST do_sd_request
 112 #define DEVICE_NR(device) (MINOR(device) >> 4)
 113 #define DEVICE_ON(device)
 114 #define DEVICE_OFF(device)
 115 
 116 #elif (MAJOR_NR == SCSI_TAPE_MAJOR)
 117 
 118 #define DEVICE_NAME "scsitape"
 119 #define DEVICE_INTR do_st  
 120 #define DEVICE_NR(device) (MINOR(device))
 121 #define DEVICE_ON(device)
 122 #define DEVICE_OFF(device)
 123 
 124 #elif (MAJOR_NR == SCSI_CDROM_MAJOR)
 125 
 126 #define DEVICE_NAME "CD-ROM"
 127 #define DEVICE_INTR do_sr
 128 #define DEVICE_REQUEST do_sr_request
 129 #define DEVICE_NR(device) (MINOR(device))
 130 #define DEVICE_ON(device)
 131 #define DEVICE_OFF(device)
 132 
 133 #elif (MAJOR_NR == XT_DISK_MAJOR)
 134 
 135 #define DEVICE_NAME "xt disk"
 136 #define DEVICE_REQUEST do_xd_request
 137 #define DEVICE_NR(device) (MINOR(device) >> 6)
 138 #define DEVICE_ON(device)
 139 #define DEVICE_OFF(device)
 140 
 141 #elif (MAJOR_NR == CDU31A_CDROM_MAJOR)
 142 
 143 #define DEVICE_NAME "CDU31A"
 144 #define DEVICE_REQUEST do_cdu31a_request
 145 #define DEVICE_NR(device) (MINOR(device))
 146 #define DEVICE_ON(device)
 147 #define DEVICE_OFF(device)
 148 
 149 #elif (MAJOR_NR == MITSUMI_CDROM_MAJOR)
 150 
 151 #define DEVICE_NAME "Mitsumi CD-ROM"
 152 /* #define DEVICE_INTR do_mcd */
 153 #define DEVICE_REQUEST do_mcd_request
 154 #define DEVICE_NR(device) (MINOR(device))
 155 #define DEVICE_ON(device)
 156 #define DEVICE_OFF(device)
 157 
 158 #elif (MAJOR_NR == MATSUSHITA_CDROM_MAJOR)
 159 
 160 #define DEVICE_NAME "Matsushita CD-ROM controller #1"
 161 #define DEVICE_REQUEST do_sbpcd_request
 162 #define DEVICE_NR(device) (MINOR(device))
 163 #define DEVICE_ON(device)
 164 #define DEVICE_OFF(device)
 165 
 166 #elif (MAJOR_NR == MATSUSHITA_CDROM2_MAJOR)
 167 
 168 #define DEVICE_NAME "Matsushita CD-ROM controller #2"
 169 #define DEVICE_REQUEST do_sbpcd2_request
 170 #define DEVICE_NR(device) (MINOR(device))
 171 #define DEVICE_ON(device)
 172 #define DEVICE_OFF(device)
 173 
 174 #elif (MAJOR_NR == MATSUSHITA_CDROM3_MAJOR)
 175 
 176 #define DEVICE_NAME "Matsushita CD-ROM controller #3"
 177 #define DEVICE_REQUEST do_sbpcd3_request
 178 #define DEVICE_NR(device) (MINOR(device))
 179 #define DEVICE_ON(device)
 180 #define DEVICE_OFF(device)
 181 
 182 #elif (MAJOR_NR == MATSUSHITA_CDROM4_MAJOR)
 183 
 184 #define DEVICE_NAME "Matsushita CD-ROM controller #4"
 185 #define DEVICE_REQUEST do_sbpcd4_request
 186 #define DEVICE_NR(device) (MINOR(device))
 187 #define DEVICE_ON(device)
 188 #define DEVICE_OFF(device)
 189 
 190 #endif
 191 
 192 #if (MAJOR_NR != SCSI_TAPE_MAJOR)
 193 
 194 #ifndef CURRENT
 195 #define CURRENT (blk_dev[MAJOR_NR].current_request)
 196 #endif
 197 
 198 #define CURRENT_DEV DEVICE_NR(CURRENT->dev)
 199 
 200 #ifdef DEVICE_INTR
 201 void (*DEVICE_INTR)(void) = NULL;
 202 #endif
 203 #ifdef DEVICE_TIMEOUT
 204 
 205 #define SET_TIMER \
 206 ((timer_table[DEVICE_TIMEOUT].expires = jiffies + TIMEOUT_VALUE), \
 207 (timer_active |= 1<<DEVICE_TIMEOUT))
 208 
 209 #define CLEAR_TIMER \
 210 timer_active &= ~(1<<DEVICE_TIMEOUT)
 211 
 212 #define SET_INTR(x) \
 213 if ((DEVICE_INTR = (x)) != NULL) \
 214         SET_TIMER; \
 215 else \
 216         CLEAR_TIMER;
 217 
 218 #else
 219 
 220 #define SET_INTR(x) (DEVICE_INTR = (x))
 221 
 222 #endif
 223 static void (DEVICE_REQUEST)(void);
 224 
 225 /* end_request() - SCSI devices have their own version */
 226 
 227 #if ! SCSI_MAJOR(MAJOR_NR)
 228 
 229 static void end_request(int uptodate)
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 230 {
 231         struct request * req;
 232         struct buffer_head * bh;
 233 
 234         req = CURRENT;
 235         req->errors = 0;
 236         if (!uptodate) {
 237                 printk(DEVICE_NAME " I/O error\n");
 238                 printk("dev %04lX, sector %lu\n",
 239                        (unsigned long)req->dev, req->sector);
 240                 req->nr_sectors--;
 241                 req->nr_sectors &= ~SECTOR_MASK;
 242                 req->sector += (BLOCK_SIZE / 512);
 243                 req->sector &= ~SECTOR_MASK;            
 244         }
 245 
 246         if ((bh = req->bh) != NULL) {
 247                 req->bh = bh->b_reqnext;
 248                 bh->b_reqnext = NULL;
 249                 bh->b_uptodate = uptodate;              
 250                 if (!uptodate) bh->b_req = 0; /* So no "Weird" errors */
 251                 unlock_buffer(bh);
 252                 if ((bh = req->bh) != NULL) {
 253                         req->current_nr_sectors = bh->b_size >> 9;
 254                         if (req->nr_sectors < req->current_nr_sectors) {
 255                                 req->nr_sectors = req->current_nr_sectors;
 256                                 printk("end_request: buffer-list destroyed\n");
 257                         }
 258                         req->buffer = bh->b_data;
 259                         return;
 260                 }
 261         }
 262         DEVICE_OFF(req->dev);
 263         CURRENT = req->next;
 264         if (req->sem != NULL)
 265                 up(req->sem);
 266         req->dev = -1;
 267         wake_up(&wait_for_request);
 268 }
 269 #endif
 270 
 271 #ifdef DEVICE_INTR
 272 #define CLEAR_INTR SET_INTR(NULL)
 273 #else
 274 #define CLEAR_INTR
 275 #endif
 276 
 277 #define INIT_REQUEST \
 278         if (!CURRENT) {\
 279                 CLEAR_INTR; \
 280                 return; \
 281         } \
 282         if (MAJOR(CURRENT->dev) != MAJOR_NR) \
 283                 panic(DEVICE_NAME ": request list destroyed"); \
 284         if (CURRENT->bh) { \
 285                 if (!CURRENT->bh->b_lock) \
 286                         panic(DEVICE_NAME ": block not locked"); \
 287         }
 288 
 289 #endif
 290 
 291 #endif
 292 #endif

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