root/fs/sysv/inode.c

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DEFINITIONS

This source file includes following definitions.
  1. sysv_put_inode
  2. detected_bs512
  3. detected_bs1024
  4. detect_xenix
  5. detected_xenix
  6. detect_sysv4
  7. detected_sysv4
  8. detect_sysv2
  9. detected_sysv2
  10. detect_coherent
  11. detected_coherent
  12. sysv_read_super
  13. sysv_write_super
  14. sysv_put_super
  15. sysv_statfs
  16. inode_bmap
  17. block_bmap
  18. sysv_bmap
  19. inode_getblk
  20. block_getblk
  21. sysv_getblk
  22. sysv_file_bread
  23. read3byte
  24. write3byte
  25. coh_read3byte
  26. coh_write3byte
  27. sysv_read_inode
  28. sysv_notify_change
  29. sysv_update_inode
  30. sysv_write_inode
  31. sysv_sync_inode
  32. init_module
  33. cleanup_module

   1 /*
   2  *  linux/fs/sysv/inode.c
   3  *
   4  *  minix/inode.c
   5  *  Copyright (C) 1991, 1992  Linus Torvalds
   6  *
   7  *  xenix/inode.c
   8  *  Copyright (C) 1992  Doug Evans
   9  *
  10  *  coh/inode.c
  11  *  Copyright (C) 1993  Pascal Haible, Bruno Haible
  12  *
  13  *  sysv/inode.c
  14  *  Copyright (C) 1993  Paul B. Monday
  15  *
  16  *  sysv/inode.c
  17  *  Copyright (C) 1993  Bruno Haible
  18  *
  19  *  This file contains code for allocating/freeing inodes and for read/writing
  20  *  the superblock.
  21  */
  22 
  23 #include <linux/sched.h>
  24 #include <linux/kernel.h>
  25 #include <linux/fs.h>
  26 #include <linux/sysv_fs.h>
  27 #include <linux/stat.h>
  28 #include <linux/string.h>
  29 #include <linux/locks.h>
  30 
  31 #include <asm/segment.h>
  32 
  33 #ifdef MODULE
  34 #include <linux/module.h>
  35 #include <linux/version.h>
  36 #else
  37 #define MOD_INC_USE_COUNT
  38 #define MOD_DEC_USE_COUNT
  39 #endif
  40 
  41 void sysv_put_inode(struct inode *inode)
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  42 {
  43         if (inode->i_nlink)
  44                 return;
  45         inode->i_size = 0;
  46         sysv_truncate(inode);
  47         sysv_free_inode(inode);
  48 }
  49 
  50 
  51 static struct super_operations sysv_sops = { 
  52         sysv_read_inode,
  53         sysv_notify_change,
  54         sysv_write_inode,
  55         sysv_put_inode,
  56         sysv_put_super,
  57         sysv_write_super,
  58         sysv_statfs,
  59         NULL
  60 };
  61 
  62 /* The following functions try to recognize specific filesystems.
  63  * We recognize:
  64  * - Xenix FS by its magic number.
  65  * - SystemV FS by its magic number.
  66  * - Coherent FS by its funny fname/fpack field.
  67  * We discriminate among SystemV4 and SystemV2 FS by the assumption that
  68  * the time stamp is not < 01-01-1980.
  69  */
  70 
  71 static void detected_bs512 (struct super_block *sb)
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  72 {
  73         sb->sv_block_size = 512;
  74         sb->sv_block_size_1 = 512-1;
  75         sb->sv_block_size_bits = 9;
  76         sb->sv_block_size_ratio = 2;
  77         sb->sv_block_size_ratio_bits = 1;
  78         sb->sv_inodes_per_block = 512/64;
  79         sb->sv_inodes_per_block_1 = 512/64-1;
  80         sb->sv_inodes_per_block_bits = 9-6;
  81         sb->sv_toobig_block = 10 + 
  82           (sb->sv_ind_per_block = 512/4) +
  83           (sb->sv_ind_per_block_2 = (512/4)*(512/4)) +
  84           (sb->sv_ind_per_block_3 = (512/4)*(512/4)*(512/4));
  85         sb->sv_ind_per_block_1 = 512/4-1;
  86         sb->sv_ind_per_block_2_1 = (512/4)*(512/4)-1;
  87         sb->sv_ind_per_block_2_bits = 2 *
  88           (sb->sv_ind_per_block_bits = 9-2);
  89         sb->sv_ind_per_block_block_size_1 = (512/4)*512-1;
  90         sb->sv_ind_per_block_block_size_bits = (9-2)+9;
  91         sb->sv_ind_per_block_2_block_size_1 = (512/4)*(512/4)*512-1;
  92         sb->sv_ind_per_block_2_block_size_bits = (9-2)+(9-2)+9;
  93         sb->sv_ind0_size = 10 * 512;
  94         sb->sv_ind1_size = (10 + (512/4))* 512;
  95         sb->sv_ind2_size = (10 + (512/4) + (512/4)*(512/4)) * 512;
  96 }
  97 
  98 static void detected_bs1024 (struct super_block *sb)
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  99 {
 100         sb->sv_block_size = 1024;
 101         sb->sv_block_size_1 = 1024-1;
 102         sb->sv_block_size_bits = 10;
 103         sb->sv_block_size_ratio = 1;
 104         sb->sv_block_size_ratio_bits = 0;
 105         sb->sv_inodes_per_block = 1024/64;
 106         sb->sv_inodes_per_block_1 = 1024/64-1;
 107         sb->sv_inodes_per_block_bits = 10-6;
 108         sb->sv_toobig_block = 10 + 
 109           (sb->sv_ind_per_block = 1024/4) +
 110           (sb->sv_ind_per_block_2 = (1024/4)*(1024/4)) +
 111           (sb->sv_ind_per_block_3 = (1024/4)*(1024/4)*(1024/4));
 112         sb->sv_ind_per_block_1 = 1024/4-1;
 113         sb->sv_ind_per_block_2_1 = (1024/4)*(1024/4)-1;
 114         sb->sv_ind_per_block_2_bits = 2 *
 115           (sb->sv_ind_per_block_bits = 10-2);
 116         sb->sv_ind_per_block_block_size_1 = (1024/4)*1024-1;
 117         sb->sv_ind_per_block_block_size_bits = (10-2)+10;
 118         sb->sv_ind_per_block_2_block_size_1 = (1024/4)*(1024/4)*1024-1;
 119         sb->sv_ind_per_block_2_block_size_bits = (10-2)+(10-2)+10;
 120         sb->sv_ind0_size = 10 * 1024;
 121         sb->sv_ind1_size = (10 + (1024/4))* 1024;
 122         sb->sv_ind2_size = (10 + (1024/4) + (1024/4)*(1024/4)) * 1024;
 123 }
 124 
 125 static const char* detect_xenix (struct super_block *sb, struct buffer_head *bh)
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 126 {
 127         struct xenix_super_block * sbd;
 128 
 129         sbd = (struct xenix_super_block *) bh->b_data;
 130         if (sbd->s_magic != 0x2b5544)
 131                 return NULL;
 132         switch (sbd->s_type) {
 133                 case 1: detected_bs512(sb); break;
 134                 case 2: detected_bs1024(sb); break;
 135                 default: return NULL;
 136         }
 137         sb->sv_type = FSTYPE_XENIX;
 138         return "Xenix";
 139 }
 140 static struct super_block * detected_xenix (struct super_block *sb, struct buffer_head *bh1, struct buffer_head *bh2)
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 141 {
 142         struct xenix_super_block * sbd1;
 143         struct xenix_super_block * sbd2;
 144 
 145         if (sb->sv_block_size == BLOCK_SIZE)
 146                 /* block size = 1024, so bh1 = bh2 */
 147                 sbd1 = sbd2 = (struct xenix_super_block *) bh1->b_data;
 148         else {
 149                 /* block size = 512, so bh1 != bh2 */
 150                 sbd1 = (struct xenix_super_block *) bh1->b_data;
 151                 sbd2 = (struct xenix_super_block *) (bh2->b_data - BLOCK_SIZE/2);
 152                 /* sanity check */
 153                 if (sbd2->s_magic != 0x2b5544)
 154                         return NULL;
 155         }
 156 
 157         sb->sv_convert = 0;
 158         sb->sv_kludge_symlinks = 1;
 159         sb->sv_truncate = 1;
 160         sb->sv_link_max = XENIX_LINK_MAX;
 161         sb->sv_fic_size = XENIX_NICINOD;
 162         sb->sv_flc_size = XENIX_NICFREE;
 163         sb->sv_bh1 = bh1;
 164         sb->sv_bh2 = bh2;
 165         sb->sv_sbd1 = (char *) sbd1;
 166         sb->sv_sbd2 = (char *) sbd2;
 167         sb->sv_sb_fic_count = &sbd1->s_ninode;
 168         sb->sv_sb_fic_inodes = &sbd1->s_inode[0];
 169         sb->sv_sb_total_free_inodes = &sbd2->s_tinode;
 170         sb->sv_sb_flc_count = &sbd1->s_nfree;
 171         sb->sv_sb_flc_blocks = &sbd1->s_free[0];
 172         sb->sv_sb_total_free_blocks = &sbd2->s_tfree;
 173         sb->sv_sb_time = &sbd2->s_time;
 174         sb->sv_block_base = 0;
 175         sb->sv_firstinodezone = 2;
 176         sb->sv_firstdatazone = sbd1->s_isize;
 177         sb->sv_nzones = sbd1->s_fsize;
 178         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 179         return sb;
 180 }
 181 
 182 static const char* detect_sysv4 (struct super_block *sb, struct buffer_head *bh)
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 183 {
 184         struct sysv4_super_block * sbd;
 185 
 186         sbd = (struct sysv4_super_block *) (bh->b_data + BLOCK_SIZE/2);
 187         if (sbd->s_magic != 0xfd187e20)
 188                 return NULL;
 189         if (sbd->s_time < 315532800) /* this is likely to happen on SystemV2 FS */
 190                 return NULL;
 191         switch (sbd->s_type) {
 192                 case 1: detected_bs512(sb); break;
 193                 case 2: detected_bs1024(sb); break;
 194                 default: return NULL;
 195         }
 196         sb->sv_type = FSTYPE_SYSV4;
 197         return "SystemV";
 198 }
 199 static struct super_block * detected_sysv4 (struct super_block *sb, struct buffer_head *bh)
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 200 {
 201         struct sysv4_super_block * sbd;
 202 
 203         if (sb->sv_block_size == BLOCK_SIZE)
 204                 sbd = (struct sysv4_super_block *) (bh->b_data + BLOCK_SIZE/2);
 205         else {
 206                 sbd = (struct sysv4_super_block *) bh->b_data;
 207                 /* sanity check */
 208                 if (sbd->s_magic != 0xfd187e20)
 209                         return NULL;
 210                 if (sbd->s_time < 315532800)
 211                         return NULL;
 212         }
 213 
 214         sb->sv_convert = 0;
 215         sb->sv_kludge_symlinks = 0; /* ?? */
 216         sb->sv_truncate = 1;
 217         sb->sv_link_max = SYSV_LINK_MAX;
 218         sb->sv_fic_size = SYSV_NICINOD;
 219         sb->sv_flc_size = SYSV_NICFREE;
 220         sb->sv_bh1 = bh;
 221         sb->sv_bh2 = bh;
 222         sb->sv_sbd1 = (char *) sbd;
 223         sb->sv_sbd2 = (char *) sbd;
 224         sb->sv_sb_fic_count = &sbd->s_ninode;
 225         sb->sv_sb_fic_inodes = &sbd->s_inode[0];
 226         sb->sv_sb_total_free_inodes = &sbd->s_tinode;
 227         sb->sv_sb_flc_count = &sbd->s_nfree;
 228         sb->sv_sb_flc_blocks = &sbd->s_free[0];
 229         sb->sv_sb_total_free_blocks = &sbd->s_tfree;
 230         sb->sv_sb_time = &sbd->s_time;
 231         sb->sv_block_base = 0;
 232         sb->sv_firstinodezone = 2;
 233         sb->sv_firstdatazone = sbd->s_isize;
 234         sb->sv_nzones = sbd->s_fsize;
 235         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 236         return sb;
 237 }
 238 
 239 static const char* detect_sysv2 (struct super_block *sb, struct buffer_head *bh)
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 240 {
 241         struct sysv2_super_block * sbd;
 242 
 243         sbd = (struct sysv2_super_block *) (bh->b_data + BLOCK_SIZE/2);
 244         if (sbd->s_magic != 0xfd187e20)
 245                 return NULL;
 246         if (sbd->s_time < 315532800) /* this is likely to happen on SystemV4 FS */
 247                 return NULL;
 248         switch (sbd->s_type) {
 249                 case 1: detected_bs512(sb); break;
 250                 case 2: detected_bs1024(sb); break;
 251                 default: return NULL;
 252         }
 253         sb->sv_type = FSTYPE_SYSV2;
 254         return "SystemV Release 2";
 255 }
 256 static struct super_block * detected_sysv2 (struct super_block *sb, struct buffer_head *bh)
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 257 {
 258         struct sysv2_super_block * sbd;
 259 
 260         if (sb->sv_block_size == BLOCK_SIZE)
 261                 sbd = (struct sysv2_super_block *) (bh->b_data + BLOCK_SIZE/2);
 262         else {
 263                 sbd = (struct sysv2_super_block *) bh->b_data;
 264                 /* sanity check */
 265                 if (sbd->s_magic != 0xfd187e20)
 266                         return NULL;
 267                 if (sbd->s_time < 315532800)
 268                         return NULL;
 269         }
 270 
 271         sb->sv_convert = 0;
 272         sb->sv_kludge_symlinks = 0; /* ?? */
 273         sb->sv_truncate = 1;
 274         sb->sv_link_max = SYSV_LINK_MAX;
 275         sb->sv_fic_size = SYSV_NICINOD;
 276         sb->sv_flc_size = SYSV_NICFREE;
 277         sb->sv_bh1 = bh;
 278         sb->sv_bh2 = bh;
 279         sb->sv_sbd1 = (char *) sbd;
 280         sb->sv_sbd2 = (char *) sbd;
 281         sb->sv_sb_fic_count = &sbd->s_ninode;
 282         sb->sv_sb_fic_inodes = &sbd->s_inode[0];
 283         sb->sv_sb_total_free_inodes = &sbd->s_tinode;
 284         sb->sv_sb_flc_count = &sbd->s_nfree;
 285         sb->sv_sb_flc_blocks = &sbd->s_free[0];
 286         sb->sv_sb_total_free_blocks = &sbd->s_tfree;
 287         sb->sv_sb_time = &sbd->s_time;
 288         sb->sv_block_base = 0;
 289         sb->sv_firstinodezone = 2;
 290         sb->sv_firstdatazone = sbd->s_isize;
 291         sb->sv_nzones = sbd->s_fsize;
 292         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 293         return sb;
 294 }
 295 
 296 static const char* detect_coherent (struct super_block *sb, struct buffer_head *bh)
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 297 {
 298         struct coh_super_block * sbd;
 299 
 300         sbd = (struct coh_super_block *) (bh->b_data + BLOCK_SIZE/2);
 301         if ((memcmp(sbd->s_fname,"noname",6) && memcmp(sbd->s_fname,"xxxxx ",6))
 302             || (memcmp(sbd->s_fpack,"nopack",6) && memcmp(sbd->s_fpack,"xxxxx\n",6)))
 303                 return NULL;
 304         detected_bs512(sb);
 305         sb->sv_type = FSTYPE_COH;
 306         return "Coherent";
 307 }
 308 static struct super_block * detected_coherent (struct super_block *sb, struct buffer_head *bh)
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 309 {
 310         struct coh_super_block * sbd;
 311 
 312         sbd = (struct coh_super_block *) bh->b_data;
 313         /* sanity check */
 314         if ((memcmp(sbd->s_fname,"noname",6) && memcmp(sbd->s_fname,"xxxxx ",6))
 315             || (memcmp(sbd->s_fpack,"nopack",6) && memcmp(sbd->s_fpack,"xxxxx\n",6)))
 316                 return NULL;
 317 
 318         sb->sv_convert = 1;
 319         sb->sv_kludge_symlinks = 1;
 320         sb->sv_truncate = 1;
 321         sb->sv_link_max = COH_LINK_MAX;
 322         sb->sv_fic_size = COH_NICINOD;
 323         sb->sv_flc_size = COH_NICFREE;
 324         sb->sv_bh1 = bh;
 325         sb->sv_bh2 = bh;
 326         sb->sv_sbd1 = (char *) sbd;
 327         sb->sv_sbd2 = (char *) sbd;
 328         sb->sv_sb_fic_count = &sbd->s_ninode;
 329         sb->sv_sb_fic_inodes = &sbd->s_inode[0];
 330         sb->sv_sb_total_free_inodes = &sbd->s_tinode;
 331         sb->sv_sb_flc_count = &sbd->s_nfree;
 332         sb->sv_sb_flc_blocks = &sbd->s_free[0];
 333         sb->sv_sb_total_free_blocks = &sbd->s_tfree;
 334         sb->sv_sb_time = &sbd->s_time;
 335         sb->sv_block_base = 0;
 336         sb->sv_firstinodezone = 2;
 337         sb->sv_firstdatazone = sbd->s_isize;
 338         sb->sv_nzones = from_coh_ulong(sbd->s_fsize);
 339         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 340         return sb;
 341 }
 342 
 343 struct super_block *sysv_read_super(struct super_block *sb,void *data, 
     /* [previous][next][first][last][top][bottom][index][help] */
 344                                      int silent)
 345 {
 346         struct buffer_head *bh;
 347         const char *found;
 348         int dev = sb->s_dev;
 349 
 350         if (1024 != sizeof (struct xenix_super_block))
 351                 panic("Xenix FS: bad super-block size");
 352         if ((512 != sizeof (struct sysv4_super_block))
 353             || (512 != sizeof (struct sysv2_super_block)))
 354                 panic("SystemV FS: bad super-block size");
 355         if (500 != sizeof (struct coh_super_block))
 356                 panic("Coherent FS: bad super-block size");
 357         if (64 != sizeof (struct sysv_inode))
 358                 panic("sysv fs: bad i-node size");
 359         MOD_INC_USE_COUNT;
 360         lock_super(sb);
 361         set_blocksize(dev,BLOCK_SIZE);
 362 
 363         /* Try to read Xenix superblock */
 364         if ((bh = bread(dev, 1, BLOCK_SIZE)) != NULL) {
 365                 if ((found = detect_xenix(sb,bh)) != NULL)
 366                         goto ok;
 367                 brelse(bh);
 368         }
 369         if ((bh = bread(dev, 0, BLOCK_SIZE)) != NULL) {
 370                 /* Try to recognize SystemV superblock */
 371                 if ((found = detect_sysv4(sb,bh)) != NULL)
 372                         goto ok;
 373                 if ((found = detect_sysv2(sb,bh)) != NULL)
 374                         goto ok;
 375                 /* Try to recognize Coherent superblock */
 376                 if ((found = detect_coherent(sb,bh)) != NULL)
 377                         goto ok;
 378                 brelse(bh);
 379         }
 380         /* Try to recognize SystemV superblock */
 381         /* Offset by 1 track, i.e. most probably 9, 15, or 18 kilobytes. */
 382         {       static int offsets[] = { 9, 15, 18, };
 383                 int i;
 384                 for (i = 0; i < sizeof(offsets)/sizeof(offsets[0]); i++)
 385                         if ((bh = bread(dev, offsets[i], BLOCK_SIZE)) != NULL) {
 386                                 /* Try to recognize SystemV superblock */
 387                                 if ((found = detect_sysv4(sb,bh)) != NULL) {
 388                                         sb->sv_block_base = offsets[i] << sb->sv_block_size_ratio_bits;
 389                                         goto ok;
 390                                 }
 391                                 if ((found = detect_sysv2(sb,bh)) != NULL) {
 392                                         sb->sv_block_base = offsets[i] << sb->sv_block_size_ratio_bits;
 393                                         goto ok;
 394                                 }
 395                                 brelse(bh);
 396                         }
 397         }
 398         sb->s_dev=0;
 399         unlock_super(sb);
 400         if (!silent)
 401                 printk("VFS: unable to read Xenix/SystemV/Coherent superblock on device %d/%d\n",MAJOR(dev),MINOR(dev));
 402         failed:
 403         MOD_DEC_USE_COUNT;
 404         return NULL;
 405 
 406         ok:
 407         if (sb->sv_block_size == BLOCK_SIZE) {
 408                 switch (sb->sv_type) {
 409                         case FSTYPE_XENIX:
 410                                 if (!detected_xenix(sb,bh,bh))
 411                                         goto bad_superblock;
 412                                 break;
 413                         case FSTYPE_SYSV4:
 414                                 if (!detected_sysv4(sb,bh))
 415                                         goto bad_superblock;
 416                                 break;
 417                         case FSTYPE_SYSV2:
 418                                 if (!detected_sysv2(sb,bh))
 419                                         goto bad_superblock;
 420                                 break;
 421                         default:
 422                         bad_superblock:
 423                                 brelse(bh);
 424                                 sb->s_dev = 0;
 425                                 unlock_super(sb);
 426                                 printk("SysV FS: cannot read superblock in 1024 byte mode\n");
 427                                 goto failed;
 428                 }
 429         } else {
 430                 /* Switch to another block size. Unfortunately, we have to
 431                    release the 1 KB block bh and read it in two parts again. */
 432                 struct buffer_head *bh1, *bh2;
 433                 unsigned long blocknr = bh->b_blocknr << sb->sv_block_size_ratio_bits;
 434 
 435                 brelse(bh);
 436                 set_blocksize(dev,sb->sv_block_size);
 437                 bh1 = NULL; bh2 = NULL;
 438                 switch (sb->sv_type) {
 439                         case FSTYPE_XENIX:
 440                                 if ((bh1 = bread(dev, blocknr, sb->sv_block_size)) == NULL)
 441                                         goto bad_superblock2;
 442                                 if ((bh2 = bread(dev, blocknr+1, sb->sv_block_size)) == NULL)
 443                                         goto bad_superblock2;
 444                                 if (!detected_xenix(sb,bh1,bh2))
 445                                         goto bad_superblock2;
 446                                 break;
 447                         case FSTYPE_SYSV4:
 448                                 if ((bh2 = bread(dev, blocknr+1, sb->sv_block_size)) == NULL)
 449                                         goto bad_superblock2;
 450                                 if (!detected_sysv4(sb,bh2))
 451                                         goto bad_superblock2;
 452                                 break;
 453                         case FSTYPE_SYSV2:
 454                                 if ((bh2 = bread(dev, blocknr+1, sb->sv_block_size)) == NULL)
 455                                         goto bad_superblock2;
 456                                 if (!detected_sysv2(sb,bh2))
 457                                         goto bad_superblock2;
 458                                 break;
 459                         case FSTYPE_COH:
 460                                 if ((bh2 = bread(dev, blocknr+1, sb->sv_block_size)) == NULL)
 461                                         goto bad_superblock2;
 462                                 if (!detected_coherent(sb,bh2))
 463                                         goto bad_superblock2;
 464                                 break;
 465                         default:
 466                         bad_superblock2:
 467                                 brelse(bh1);
 468                                 brelse(bh2);
 469                                 set_blocksize(sb->s_dev,BLOCK_SIZE);
 470                                 sb->s_dev = 0;
 471                                 unlock_super(sb);
 472                                 printk("SysV FS: cannot read superblock in 512 byte mode\n");
 473                                 goto failed;
 474                 }
 475         }
 476         sb->sv_ninodes = (sb->sv_firstdatazone - sb->sv_firstinodezone) << sb->sv_inodes_per_block_bits;
 477         if (!silent)
 478                 printk("VFS: Found a %s FS (block size = %d) on device %d/%d\n",found,sb->sv_block_size,MAJOR(dev),MINOR(dev));
 479         sb->s_magic = SYSV_MAGIC_BASE + sb->sv_type;
 480         /* The buffer code now supports block size 512 as well as 1024. */
 481         sb->s_blocksize = sb->sv_block_size;
 482         sb->s_blocksize_bits = sb->sv_block_size_bits;
 483         /* set up enough so that it can read an inode */
 484         sb->s_dev = dev;
 485         sb->s_op = &sysv_sops;
 486         sb->s_mounted = iget(sb,SYSV_ROOT_INO);
 487         unlock_super(sb);
 488         if (!sb->s_mounted) {
 489                 printk("SysV FS: get root inode failed\n");
 490                 sysv_put_super(sb);
 491                 return NULL;
 492         }
 493         sb->s_dirt = 1;
 494         /* brelse(bh);  resp.  brelse(bh1); brelse(bh2);
 495            occurs when the disk is unmounted. */
 496         return sb;
 497 }
 498 
 499 /* This is only called on sync() and umount(), when s_dirt=1. */
 500 void sysv_write_super (struct super_block *sb)
     /* [previous][next][first][last][top][bottom][index][help] */
 501 {
 502         lock_super(sb);
 503         if (sb->sv_bh1->b_dirt || sb->sv_bh2->b_dirt) {
 504                 /* If we are going to write out the super block,
 505                    then attach current time stamp. */
 506                 unsigned long time = CURRENT_TIME;
 507                 if (sb->sv_convert)
 508                         time = to_coh_ulong(time);
 509                 *sb->sv_sb_time = time;
 510                 mark_buffer_dirty(sb->sv_bh2, 1);
 511         }
 512         sb->s_dirt = 0;
 513         unlock_super(sb);
 514 }
 515 
 516 void sysv_put_super(struct super_block *sb)
     /* [previous][next][first][last][top][bottom][index][help] */
 517 {
 518         /* we can assume sysv_write_super() has already been called */
 519         lock_super(sb);
 520         brelse(sb->sv_bh1);
 521         if (sb->sv_bh1 != sb->sv_bh2) brelse(sb->sv_bh2);
 522         /* switch back to default block size */
 523         if (sb->s_blocksize != BLOCK_SIZE)
 524                 set_blocksize(sb->s_dev,BLOCK_SIZE);
 525         sb->s_dev = 0;
 526         unlock_super(sb);
 527         MOD_DEC_USE_COUNT;
 528 }
 529 
 530 void sysv_statfs(struct super_block *sb, struct statfs *buf)
     /* [previous][next][first][last][top][bottom][index][help] */
 531 {
 532         long tmp;
 533 
 534         put_fs_long(sb->s_magic, &buf->f_type);         /* type of filesystem */
 535         put_fs_long(sb->sv_block_size, &buf->f_bsize);  /* block size */
 536         put_fs_long(sb->sv_ndatazones, &buf->f_blocks); /* total data blocks in file system */
 537         tmp = sysv_count_free_blocks(sb);
 538         put_fs_long(tmp, &buf->f_bfree);                /* free blocks in fs */
 539         put_fs_long(tmp, &buf->f_bavail);               /* free blocks available to non-superuser */
 540         put_fs_long(sb->sv_ninodes, &buf->f_files);     /* total file nodes in file system */
 541         put_fs_long(sysv_count_free_inodes(sb), &buf->f_ffree); /* free file nodes in fs */
 542         put_fs_long(SYSV_NAMELEN, &buf->f_namelen);
 543         /* Don't know what value to put in buf->f_fsid */       /* file system id */
 544 }
 545 
 546 
 547 /* bmap support for running executables and shared libraries. */
 548 
 549 static inline int inode_bmap(struct super_block * sb, struct inode * inode, int nr)
     /* [previous][next][first][last][top][bottom][index][help] */
 550 {
 551         int tmp = inode->u.sysv_i.i_data[nr];
 552         if (!tmp)
 553                 return 0;
 554         return tmp + sb->sv_block_base;
 555 }
 556 
 557 static int block_bmap(struct super_block * sb, struct buffer_head * bh, int nr, int convert)
     /* [previous][next][first][last][top][bottom][index][help] */
 558 {
 559         int tmp;
 560 
 561         if (!bh)
 562                 return 0;
 563         tmp = ((sysv_zone_t *) bh->b_data) [nr];
 564         if (convert)
 565                 tmp = from_coh_ulong(tmp);
 566         brelse(bh);
 567         if (!tmp)
 568                 return 0;
 569         return tmp + sb->sv_block_base;
 570 }
 571 
 572 int sysv_bmap(struct inode * inode,int block_nr)
     /* [previous][next][first][last][top][bottom][index][help] */
 573 {
 574         unsigned int block = block_nr;
 575         struct super_block * sb = inode->i_sb;
 576         int convert;
 577         int i;
 578         struct buffer_head * bh;
 579 
 580         if (block < 10)
 581                 return inode_bmap(sb,inode,block);
 582         block -= 10;
 583         convert = sb->sv_convert;
 584         if (block < sb->sv_ind_per_block) {
 585                 i = inode_bmap(sb,inode,10);
 586                 if (!i)
 587                         return 0;
 588                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 589                 return block_bmap(sb, bh, block, convert);
 590         }
 591         block -= sb->sv_ind_per_block;
 592         if (block < sb->sv_ind_per_block_2) {
 593                 i = inode_bmap(sb,inode,11);
 594                 if (!i)
 595                         return 0;
 596                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 597                 i = block_bmap(sb, bh, block >> sb->sv_ind_per_block_bits, convert);
 598                 if (!i)
 599                         return 0;
 600                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 601                 return block_bmap(sb, bh, block & sb->sv_ind_per_block_1, convert);
 602         }
 603         block -= sb->sv_ind_per_block_2;
 604         if (block < sb->sv_ind_per_block_3) {
 605                 i = inode_bmap(sb,inode,12);
 606                 if (!i)
 607                         return 0;
 608                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 609                 i = block_bmap(sb, bh, block >> sb->sv_ind_per_block_2_bits, convert);
 610                 if (!i)
 611                         return 0;
 612                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 613                 i = block_bmap(sb, bh, (block >> sb->sv_ind_per_block_bits) & sb->sv_ind_per_block_1,convert);
 614                 if (!i)
 615                         return 0;
 616                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 617                 return block_bmap(sb, bh, block & sb->sv_ind_per_block_1, convert);
 618         }
 619         if ((int)block<0) {
 620                 printk("sysv_bmap: block<0");
 621                 return 0;
 622         }
 623         printk("sysv_bmap: block>big");
 624         return 0;
 625 }
 626 
 627 /* End of bmap support. */
 628 
 629 
 630 /* Access selected blocks of regular files (or directories) */
 631 
 632 static struct buffer_head * inode_getblk(struct inode * inode, int nr, int create)
     /* [previous][next][first][last][top][bottom][index][help] */
 633 {
 634         struct super_block *sb;
 635         unsigned long tmp;
 636         unsigned long *p;
 637         struct buffer_head * result;
 638 
 639         sb = inode->i_sb;
 640         p = inode->u.sysv_i.i_data + nr;
 641 repeat:
 642         tmp = *p;
 643         if (tmp) {
 644                 result = sv_getblk(sb, inode->i_dev, tmp);
 645                 if (tmp == *p)
 646                         return result;
 647                 brelse(result);
 648                 goto repeat;
 649         }
 650         if (!create)
 651                 return NULL;
 652         tmp = sysv_new_block(sb);
 653         if (!tmp)
 654                 return NULL;
 655         result = sv_getblk(sb, inode->i_dev, tmp);
 656         if (*p) {
 657                 sysv_free_block(sb,tmp);
 658                 brelse(result);
 659                 goto repeat;
 660         }
 661         *p = tmp;
 662         inode->i_ctime = CURRENT_TIME;
 663         inode->i_dirt = 1;
 664         return result;
 665 }
 666 
 667 static struct buffer_head * block_getblk(struct inode * inode, 
     /* [previous][next][first][last][top][bottom][index][help] */
 668         struct buffer_head * bh, int nr, int create)
 669 {
 670         struct super_block *sb;
 671         unsigned long tmp, block;
 672         sysv_zone_t *p;
 673         struct buffer_head * result;
 674 
 675         if (!bh)
 676                 return NULL;
 677         if (!bh->b_uptodate) {
 678                 ll_rw_block(READ, 1, &bh);
 679                 wait_on_buffer(bh);
 680                 if (!bh->b_uptodate) {
 681                         brelse(bh);
 682                         return NULL;
 683                 }
 684         }
 685         sb = inode->i_sb;
 686         p = nr + (sysv_zone_t *) bh->b_data;
 687 repeat:
 688         block = tmp = *p;
 689         if (sb->sv_convert)
 690                 block = from_coh_ulong(block);
 691         if (tmp) {
 692                 result = sv_getblk(sb, bh->b_dev, block);
 693                 if (tmp == *p) {
 694                         brelse(bh);
 695                         return result;
 696                 }
 697                 brelse(result);
 698                 goto repeat;
 699         }
 700         if (!create) {
 701                 brelse(bh);
 702                 return NULL;
 703         }
 704         block = sysv_new_block(sb);
 705         if (!block) {
 706                 brelse(bh);
 707                 return NULL;
 708         }
 709         result = sv_getblk(sb, bh->b_dev, block);
 710         if (*p) {
 711                 sysv_free_block(sb,block);
 712                 brelse(result);
 713                 goto repeat;
 714         }
 715         *p = (sb->sv_convert ? to_coh_ulong(block) : block);
 716         mark_buffer_dirty(bh, 1);
 717         brelse(bh);
 718         return result;
 719 }
 720 
 721 struct buffer_head * sysv_getblk(struct inode * inode, unsigned int block, int create)
     /* [previous][next][first][last][top][bottom][index][help] */
 722 {
 723         struct super_block * sb = inode->i_sb;
 724         struct buffer_head * bh;
 725 
 726         if (block < 10)
 727                 return inode_getblk(inode,block,create);
 728         block -= 10;
 729         if (block < sb->sv_ind_per_block) {
 730                 bh = inode_getblk(inode,10,create);
 731                 return block_getblk(inode, bh, block, create);
 732         }
 733         block -= sb->sv_ind_per_block;
 734         if (block < sb->sv_ind_per_block_2) {
 735                 bh = inode_getblk(inode,11,create);
 736                 bh = block_getblk(inode, bh, block >> sb->sv_ind_per_block_bits, create);
 737                 return block_getblk(inode, bh, block & sb->sv_ind_per_block_1, create);
 738         }
 739         block -= sb->sv_ind_per_block_2;
 740         if (block < sb->sv_ind_per_block_3) {
 741                 bh = inode_getblk(inode,12,create);
 742                 bh = block_getblk(inode, bh, block >> sb->sv_ind_per_block_2_bits, create);
 743                 bh = block_getblk(inode, bh, (block >> sb->sv_ind_per_block_bits) & sb->sv_ind_per_block_1, create);
 744                 return block_getblk(inode, bh, block & sb->sv_ind_per_block_1, create);
 745         }
 746         if ((int)block<0) {
 747                 printk("sysv_getblk: block<0");
 748                 return NULL;
 749         }
 750         printk("sysv_getblk: block>big");
 751         return NULL;
 752 }
 753 
 754 struct buffer_head * sysv_file_bread(struct inode * inode, int block, int create)
     /* [previous][next][first][last][top][bottom][index][help] */
 755 {
 756         struct buffer_head * bh;
 757 
 758         bh = sysv_getblk(inode,block,create);
 759         if (!bh || bh->b_uptodate)
 760                 return bh;
 761         ll_rw_block(READ, 1, &bh);
 762         wait_on_buffer(bh);
 763         if (bh->b_uptodate)
 764                 return bh;
 765         brelse(bh);
 766         return NULL;
 767 }
 768 
 769 
 770 static inline unsigned long read3byte (char * p)
     /* [previous][next][first][last][top][bottom][index][help] */
 771 {
 772         return (unsigned long)(*(unsigned short *)p)
 773              | (unsigned long)(*(unsigned char *)(p+2)) << 16;
 774 }
 775 
 776 static inline void write3byte (char * p, unsigned long val)
     /* [previous][next][first][last][top][bottom][index][help] */
 777 {
 778         *(unsigned short *)p = (unsigned short) val;
 779         *(unsigned char *)(p+2) = val >> 16;
 780 }
 781 
 782 static inline unsigned long coh_read3byte (char * p)
     /* [previous][next][first][last][top][bottom][index][help] */
 783 {
 784         return (unsigned long)(*(unsigned char *)p) << 16
 785              | (unsigned long)(*(unsigned short *)(p+1));
 786 }
 787 
 788 static inline void coh_write3byte (char * p, unsigned long val)
     /* [previous][next][first][last][top][bottom][index][help] */
 789 {
 790         *(unsigned char *)p = val >> 16;
 791         *(unsigned short *)(p+1) = (unsigned short) val;
 792 }
 793 
 794 void sysv_read_inode(struct inode * inode)
     /* [previous][next][first][last][top][bottom][index][help] */
 795 {
 796         struct super_block * sb = inode->i_sb;
 797         struct buffer_head * bh;
 798         struct sysv_inode * raw_inode;
 799         unsigned int block, ino;
 800         umode_t mode;
 801 
 802         ino = inode->i_ino;
 803         inode->i_op = NULL;
 804         inode->i_mode = 0;
 805         if (!ino || ino > sb->sv_ninodes) {
 806                 printk("Bad inode number on dev 0x%04x: %d is out of range\n",
 807                         inode->i_dev, ino);
 808                 return;
 809         }
 810         block = sb->sv_firstinodezone + ((ino-1) >> sb->sv_inodes_per_block_bits);
 811         if (!(bh = sv_bread(sb,inode->i_dev,block))) {
 812                 printk("Major problem: unable to read inode from dev 0x%04x\n",
 813                         inode->i_dev);
 814                 return;
 815         }
 816         raw_inode = (struct sysv_inode *) bh->b_data + ((ino-1) & sb->sv_inodes_per_block_1);
 817         mode = raw_inode->i_mode;
 818         if (sb->sv_kludge_symlinks)
 819                 mode = from_coh_imode(mode);
 820         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 821         inode->i_mode = mode;
 822         inode->i_uid = raw_inode->i_uid;
 823         inode->i_gid = raw_inode->i_gid;
 824         inode->i_nlink = raw_inode->i_nlink;
 825         if (sb->sv_convert) {
 826                 inode->i_size = from_coh_ulong(raw_inode->i_size);
 827                 inode->i_atime = from_coh_ulong(raw_inode->i_atime);
 828                 inode->i_mtime = from_coh_ulong(raw_inode->i_mtime);
 829                 inode->i_ctime = from_coh_ulong(raw_inode->i_ctime);
 830         } else {
 831                 inode->i_size = raw_inode->i_size;
 832                 inode->i_atime = raw_inode->i_atime;
 833                 inode->i_mtime = raw_inode->i_mtime;
 834                 inode->i_ctime = raw_inode->i_ctime;
 835         }
 836         inode->i_blocks = inode->i_blksize = 0;
 837         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 838                 inode->i_rdev = raw_inode->i_a.i_rdev;
 839         else
 840         if (sb->sv_convert)
 841                 for (block = 0; block < 10+1+1+1; block++)
 842                         inode->u.sysv_i.i_data[block] =
 843                                 coh_read3byte(&raw_inode->i_a.i_addb[3*block]);
 844         else
 845                 for (block = 0; block < 10+1+1+1; block++)
 846                         inode->u.sysv_i.i_data[block] =
 847                                 read3byte(&raw_inode->i_a.i_addb[3*block]);
 848         brelse(bh);
 849         if (S_ISREG(inode->i_mode))
 850                 inode->i_op = &sysv_file_inode_operations;
 851         else if (S_ISDIR(inode->i_mode))
 852                 inode->i_op = &sysv_dir_inode_operations;
 853         else if (S_ISLNK(inode->i_mode))
 854                 inode->i_op = &sysv_symlink_inode_operations;
 855         else if (S_ISCHR(inode->i_mode))
 856                 inode->i_op = &chrdev_inode_operations;
 857         else if (S_ISBLK(inode->i_mode))
 858                 inode->i_op = &blkdev_inode_operations;
 859         else if (S_ISFIFO(inode->i_mode))
 860                 init_fifo(inode);
 861 }
 862 
 863 /* To avoid inconsistencies between inodes in memory and inodes on disk. */
 864 extern int sysv_notify_change(struct inode *inode, struct iattr *attr)
     /* [previous][next][first][last][top][bottom][index][help] */
 865 {
 866         int error;
 867 
 868         if ((error = inode_change_ok(inode, attr)) != 0)
 869                 return error;
 870 
 871         if (attr->ia_valid & ATTR_MODE)
 872                 if (inode->i_sb->sv_kludge_symlinks)
 873                         if (attr->ia_mode == COH_KLUDGE_SYMLINK_MODE)
 874                                 attr->ia_mode = COH_KLUDGE_NOT_SYMLINK;
 875 
 876         inode_setattr(inode, attr);
 877 
 878         return 0;
 879 }
 880 
 881 static struct buffer_head * sysv_update_inode(struct inode * inode)
     /* [previous][next][first][last][top][bottom][index][help] */
 882 {
 883         struct super_block * sb = inode->i_sb;
 884         struct buffer_head * bh;
 885         struct sysv_inode * raw_inode;
 886         unsigned int ino, block;
 887         umode_t mode;
 888 
 889         ino = inode->i_ino;
 890         if (!ino || ino > sb->sv_ninodes) {
 891                 printk("Bad inode number on dev 0x%04x: %d is out of range\n",
 892                         inode->i_dev, ino);
 893                 inode->i_dirt = 0;
 894                 return 0;
 895         }
 896         block = sb->sv_firstinodezone + ((ino-1) >> sb->sv_inodes_per_block_bits);
 897         if (!(bh = sv_bread(sb,inode->i_dev,block))) {
 898                 printk("unable to read i-node block\n");
 899                 inode->i_dirt = 0;
 900                 return 0;
 901         }
 902         raw_inode = (struct sysv_inode *) bh->b_data + ((ino-1) & sb->sv_inodes_per_block_1);
 903         mode = inode->i_mode;
 904         if (sb->sv_kludge_symlinks)
 905                 mode = to_coh_imode(mode);
 906         raw_inode->i_mode = mode;
 907         raw_inode->i_uid = inode->i_uid;
 908         raw_inode->i_gid = inode->i_gid;
 909         raw_inode->i_nlink = inode->i_nlink;
 910         if (sb->sv_convert) {
 911                 raw_inode->i_size = to_coh_ulong(inode->i_size);
 912                 raw_inode->i_atime = to_coh_ulong(inode->i_atime);
 913                 raw_inode->i_mtime = to_coh_ulong(inode->i_mtime);
 914                 raw_inode->i_ctime = to_coh_ulong(inode->i_ctime);
 915         } else {
 916                 raw_inode->i_size = inode->i_size;
 917                 raw_inode->i_atime = inode->i_atime;
 918                 raw_inode->i_mtime = inode->i_mtime;
 919                 raw_inode->i_ctime = inode->i_ctime;
 920         }
 921         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 922                 raw_inode->i_a.i_rdev = inode->i_rdev; /* write 2 or 3 bytes ?? */
 923         else
 924         if (sb->sv_convert)
 925                 for (block = 0; block < 10+1+1+1; block++)
 926                         coh_write3byte(&raw_inode->i_a.i_addb[3*block],inode->u.sysv_i.i_data[block]);
 927         else
 928                 for (block = 0; block < 10+1+1+1; block++)
 929                         write3byte(&raw_inode->i_a.i_addb[3*block],inode->u.sysv_i.i_data[block]);
 930         inode->i_dirt=0;
 931         mark_buffer_dirty(bh, 1);
 932         return bh;
 933 }
 934 
 935 void sysv_write_inode(struct inode * inode)
     /* [previous][next][first][last][top][bottom][index][help] */
 936 {
 937         struct buffer_head *bh;
 938         bh = sysv_update_inode(inode);
 939         brelse(bh);
 940 }
 941 
 942 int sysv_sync_inode(struct inode * inode)
     /* [previous][next][first][last][top][bottom][index][help] */
 943 {
 944         int err = 0;
 945         struct buffer_head *bh;
 946 
 947         bh = sysv_update_inode(inode);
 948         if (bh && bh->b_dirt) {
 949                 ll_rw_block(WRITE, 1, &bh);
 950                 wait_on_buffer(bh);
 951                 if (bh->b_req && !bh->b_uptodate)
 952                 {
 953                         printk ("IO error syncing sysv inode [%04x:%08lx]\n",
 954                                 inode->i_dev, inode->i_ino);
 955                         err = -1;
 956                 }
 957         }
 958         else if (!bh)
 959                 err = -1;
 960         brelse (bh);
 961         return err;
 962 }
 963 
 964 #ifdef MODULE
 965 
 966 /* Every kernel module contains stuff like this. */
 967 
 968 char kernel_version[] = UTS_RELEASE;
 969 
 970 static struct file_system_type sysv_fs_type[3] = {
 971         {sysv_read_super, "xenix", 1, NULL},
 972         {sysv_read_super, "sysv", 1, NULL},
 973         {sysv_read_super, "coherent", 1, NULL}
 974 };
 975 
 976 int init_module(void)
     /* [previous][next][first][last][top][bottom][index][help] */
 977 {
 978         int i;
 979 
 980         for (i = 0; i < 3; i++)
 981                 register_filesystem(&sysv_fs_type[i]);
 982 
 983         return 0;
 984 }
 985 
 986 void cleanup_module(void)
     /* [previous][next][first][last][top][bottom][index][help] */
 987 {
 988         int i;
 989 
 990         if (MOD_IN_USE) {
 991                 printk("SysV FS cannot be removed, currently in use\n");
 992                 return;
 993         }
 994 
 995         for (i = 0; i < 3; i++)
 996                 unregister_filesystem(&sysv_fs_type[i]);
 997 }
 998 
 999 #endif

/* [previous][next][first][last][top][bottom][index][help] */