fs/sysv/inode.c

/* */
This source file includes following definitions.
sysv_put_inode
detected_bs512
detected_bs1024
detect_xenix
detected_xenix
detect_sysv4
detected_sysv4
detect_sysv2
detected_sysv2
detect_coherent
detected_coherent
sysv_read_super
sysv_write_super
sysv_put_super
sysv_statfs
inode_bmap
block_bmap
sysv_bmap
inode_getblk
block_getblk
sysv_getblk
sysv_file_bread
read3byte
write3byte
coh_read3byte
coh_write3byte
sysv_read_inode
sysv_notify_change
sysv_update_inode
sysv_write_inode
sysv_sync_inode
init_module
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 #ifdef MODULE
  24 #include <linux/module.h>
  25 #include <linux/version.h>
  26 #else
  27 #define MOD_INC_USE_COUNT
  28 #define MOD_DEC_USE_COUNT
  29 #endif
  30 
  31 #include <linux/sched.h>
  32 #include <linux/kernel.h>
  33 #include <linux/fs.h>
  34 #include <linux/sysv_fs.h>
  35 #include <linux/stat.h>
  36 #include <linux/string.h>
  37 #include <linux/locks.h>
  38 
  39 #include <asm/segment.h>
  40 
  41 void sysv_put_inode(struct inode *inode)
     /*  */
  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)
     /*  */
  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)
     /*  */
  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)
     /*  */
 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)
     /*  */
 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)
     /*  */
 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)
     /*  */
 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_sb_state = &sbd->s_state;
 232         sb->sv_block_base = 0;
 233         sb->sv_firstinodezone = 2;
 234         sb->sv_firstdatazone = sbd->s_isize;
 235         sb->sv_nzones = sbd->s_fsize;
 236         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 237         return sb;
 238 }
 239 
 240 static const char* detect_sysv2 (struct super_block *sb, struct buffer_head *bh)
     /*  */
 241 {
 242         struct sysv2_super_block * sbd;
 243 
 244         sbd = (struct sysv2_super_block *) (bh->b_data + BLOCK_SIZE/2);
 245         if (sbd->s_magic != 0xfd187e20)
 246                 return NULL;
 247         if (sbd->s_time < 315532800) /* this is likely to happen on SystemV4 FS */
 248                 return NULL;
 249         switch (sbd->s_type) {
 250                 case 1: detected_bs512(sb); break;
 251                 case 2: detected_bs1024(sb); break;
 252                 default: return NULL;
 253         }
 254         sb->sv_type = FSTYPE_SYSV2;
 255         return "SystemV Release 2";
 256 }
 257 static struct super_block * detected_sysv2 (struct super_block *sb, struct buffer_head *bh)
     /*  */
 258 {
 259         struct sysv2_super_block * sbd;
 260 
 261         if (sb->sv_block_size == BLOCK_SIZE)
 262                 sbd = (struct sysv2_super_block *) (bh->b_data + BLOCK_SIZE/2);
 263         else {
 264                 sbd = (struct sysv2_super_block *) bh->b_data;
 265                 /* sanity check */
 266                 if (sbd->s_magic != 0xfd187e20)
 267                         return NULL;
 268                 if (sbd->s_time < 315532800)
 269                         return NULL;
 270         }
 271 
 272         sb->sv_convert = 0;
 273         sb->sv_kludge_symlinks = 0; /* ?? */
 274         sb->sv_truncate = 1;
 275         sb->sv_link_max = SYSV_LINK_MAX;
 276         sb->sv_fic_size = SYSV_NICINOD;
 277         sb->sv_flc_size = SYSV_NICFREE;
 278         sb->sv_bh1 = bh;
 279         sb->sv_bh2 = bh;
 280         sb->sv_sbd1 = (char *) sbd;
 281         sb->sv_sbd2 = (char *) sbd;
 282         sb->sv_sb_fic_count = &sbd->s_ninode;
 283         sb->sv_sb_fic_inodes = &sbd->s_inode[0];
 284         sb->sv_sb_total_free_inodes = &sbd->s_tinode;
 285         sb->sv_sb_flc_count = &sbd->s_nfree;
 286         sb->sv_sb_flc_blocks = &sbd->s_free[0];
 287         sb->sv_sb_total_free_blocks = &sbd->s_tfree;
 288         sb->sv_sb_time = &sbd->s_time;
 289         sb->sv_sb_state = &sbd->s_state;
 290         sb->sv_block_base = 0;
 291         sb->sv_firstinodezone = 2;
 292         sb->sv_firstdatazone = sbd->s_isize;
 293         sb->sv_nzones = sbd->s_fsize;
 294         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 295         return sb;
 296 }
 297 
 298 static const char* detect_coherent (struct super_block *sb, struct buffer_head *bh)
     /*  */
 299 {
 300         struct coh_super_block * sbd;
 301 
 302         sbd = (struct coh_super_block *) (bh->b_data + BLOCK_SIZE/2);
 303         if ((memcmp(sbd->s_fname,"noname",6) && memcmp(sbd->s_fname,"xxxxx ",6))
 304             || (memcmp(sbd->s_fpack,"nopack",6) && memcmp(sbd->s_fpack,"xxxxx\n",6)))
 305                 return NULL;
 306         detected_bs512(sb);
 307         sb->sv_type = FSTYPE_COH;
 308         return "Coherent";
 309 }
 310 static struct super_block * detected_coherent (struct super_block *sb, struct buffer_head *bh)
     /*  */
 311 {
 312         struct coh_super_block * sbd;
 313 
 314         sbd = (struct coh_super_block *) bh->b_data;
 315         /* sanity check */
 316         if ((memcmp(sbd->s_fname,"noname",6) && memcmp(sbd->s_fname,"xxxxx ",6))
 317             || (memcmp(sbd->s_fpack,"nopack",6) && memcmp(sbd->s_fpack,"xxxxx\n",6)))
 318                 return NULL;
 319 
 320         sb->sv_convert = 1;
 321         sb->sv_kludge_symlinks = 1;
 322         sb->sv_truncate = 1;
 323         sb->sv_link_max = COH_LINK_MAX;
 324         sb->sv_fic_size = COH_NICINOD;
 325         sb->sv_flc_size = COH_NICFREE;
 326         sb->sv_bh1 = bh;
 327         sb->sv_bh2 = bh;
 328         sb->sv_sbd1 = (char *) sbd;
 329         sb->sv_sbd2 = (char *) sbd;
 330         sb->sv_sb_fic_count = &sbd->s_ninode;
 331         sb->sv_sb_fic_inodes = &sbd->s_inode[0];
 332         sb->sv_sb_total_free_inodes = &sbd->s_tinode;
 333         sb->sv_sb_flc_count = &sbd->s_nfree;
 334         sb->sv_sb_flc_blocks = &sbd->s_free[0];
 335         sb->sv_sb_total_free_blocks = &sbd->s_tfree;
 336         sb->sv_sb_time = &sbd->s_time;
 337         sb->sv_block_base = 0;
 338         sb->sv_firstinodezone = 2;
 339         sb->sv_firstdatazone = sbd->s_isize;
 340         sb->sv_nzones = from_coh_ulong(sbd->s_fsize);
 341         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 342         return sb;
 343 }
 344 
 345 struct super_block *sysv_read_super(struct super_block *sb,void *data, 
     /*  */
 346                                      int silent)
 347 {
 348         struct buffer_head *bh;
 349         const char *found;
 350         int dev = sb->s_dev;
 351 
 352         if (1024 != sizeof (struct xenix_super_block))
 353                 panic("Xenix FS: bad super-block size");
 354         if ((512 != sizeof (struct sysv4_super_block))
 355             || (512 != sizeof (struct sysv2_super_block)))
 356                 panic("SystemV FS: bad super-block size");
 357         if (500 != sizeof (struct coh_super_block))
 358                 panic("Coherent FS: bad super-block size");
 359         if (64 != sizeof (struct sysv_inode))
 360                 panic("sysv fs: bad i-node size");
 361         MOD_INC_USE_COUNT;
 362         lock_super(sb);
 363         set_blocksize(dev,BLOCK_SIZE);
 364 
 365         /* Try to read Xenix superblock */
 366         if ((bh = bread(dev, 1, BLOCK_SIZE)) != NULL) {
 367                 if ((found = detect_xenix(sb,bh)) != NULL)
 368                         goto ok;
 369                 brelse(bh);
 370         }
 371         if ((bh = bread(dev, 0, BLOCK_SIZE)) != NULL) {
 372                 /* Try to recognize SystemV superblock */
 373                 if ((found = detect_sysv4(sb,bh)) != NULL)
 374                         goto ok;
 375                 if ((found = detect_sysv2(sb,bh)) != NULL)
 376                         goto ok;
 377                 /* Try to recognize Coherent superblock */
 378                 if ((found = detect_coherent(sb,bh)) != NULL)
 379                         goto ok;
 380                 brelse(bh);
 381         }
 382         /* Try to recognize SystemV superblock */
 383         /* Offset by 1 track, i.e. most probably 9, 15, or 18 kilobytes. */
 384         {       static int offsets[] = { 9, 15, 18, };
 385                 int i;
 386                 for (i = 0; i < sizeof(offsets)/sizeof(offsets[0]); i++)
 387                         if ((bh = bread(dev, offsets[i], BLOCK_SIZE)) != NULL) {
 388                                 /* Try to recognize SystemV superblock */
 389                                 if ((found = detect_sysv4(sb,bh)) != NULL) {
 390                                         sb->sv_block_base = offsets[i] << sb->sv_block_size_ratio_bits;
 391                                         goto ok;
 392                                 }
 393                                 if ((found = detect_sysv2(sb,bh)) != NULL) {
 394                                         sb->sv_block_base = offsets[i] << sb->sv_block_size_ratio_bits;
 395                                         goto ok;
 396                                 }
 397                                 brelse(bh);
 398                         }
 399         }
 400         sb->s_dev=0;
 401         unlock_super(sb);
 402         if (!silent)
 403                 printk("VFS: unable to read Xenix/SystemV/Coherent superblock on device %d/%d\n",MAJOR(dev),MINOR(dev));
 404         failed:
 405         MOD_DEC_USE_COUNT;
 406         return NULL;
 407 
 408         ok:
 409         if (sb->sv_block_size == BLOCK_SIZE) {
 410                 switch (sb->sv_type) {
 411                         case FSTYPE_XENIX:
 412                                 if (!detected_xenix(sb,bh,bh))
 413                                         goto bad_superblock;
 414                                 break;
 415                         case FSTYPE_SYSV4:
 416                                 if (!detected_sysv4(sb,bh))
 417                                         goto bad_superblock;
 418                                 break;
 419                         case FSTYPE_SYSV2:
 420                                 if (!detected_sysv2(sb,bh))
 421                                         goto bad_superblock;
 422                                 break;
 423                         default:
 424                         bad_superblock:
 425                                 brelse(bh);
 426                                 sb->s_dev = 0;
 427                                 unlock_super(sb);
 428                                 printk("SysV FS: cannot read superblock in 1024 byte mode\n");
 429                                 goto failed;
 430                 }
 431         } else {
 432                 /* Switch to another block size. Unfortunately, we have to
 433                    release the 1 KB block bh and read it in two parts again. */
 434                 struct buffer_head *bh1, *bh2;
 435                 unsigned long blocknr = bh->b_blocknr << sb->sv_block_size_ratio_bits;
 436 
 437                 brelse(bh);
 438                 set_blocksize(dev,sb->sv_block_size);
 439                 bh1 = NULL; bh2 = NULL;
 440                 switch (sb->sv_type) {
 441                         case FSTYPE_XENIX:
 442                                 if ((bh1 = bread(dev, blocknr, sb->sv_block_size)) == NULL)
 443                                         goto bad_superblock2;
 444                                 if ((bh2 = bread(dev, blocknr+1, sb->sv_block_size)) == NULL)
 445                                         goto bad_superblock2;
 446                                 if (!detected_xenix(sb,bh1,bh2))
 447                                         goto bad_superblock2;
 448                                 break;
 449                         case FSTYPE_SYSV4:
 450                                 if ((bh2 = bread(dev, blocknr+1, sb->sv_block_size)) == NULL)
 451                                         goto bad_superblock2;
 452                                 if (!detected_sysv4(sb,bh2))
 453                                         goto bad_superblock2;
 454                                 break;
 455                         case FSTYPE_SYSV2:
 456                                 if ((bh2 = bread(dev, blocknr+1, sb->sv_block_size)) == NULL)
 457                                         goto bad_superblock2;
 458                                 if (!detected_sysv2(sb,bh2))
 459                                         goto bad_superblock2;
 460                                 break;
 461                         case FSTYPE_COH:
 462                                 if ((bh2 = bread(dev, blocknr+1, sb->sv_block_size)) == NULL)
 463                                         goto bad_superblock2;
 464                                 if (!detected_coherent(sb,bh2))
 465                                         goto bad_superblock2;
 466                                 break;
 467                         default:
 468                         bad_superblock2:
 469                                 brelse(bh1);
 470                                 brelse(bh2);
 471                                 set_blocksize(sb->s_dev,BLOCK_SIZE);
 472                                 sb->s_dev = 0;
 473                                 unlock_super(sb);
 474                                 printk("SysV FS: cannot read superblock in 512 byte mode\n");
 475                                 goto failed;
 476                 }
 477         }
 478         sb->sv_ninodes = (sb->sv_firstdatazone - sb->sv_firstinodezone) << sb->sv_inodes_per_block_bits;
 479         if (!silent)
 480                 printk("VFS: Found a %s FS (block size = %d) on device %d/%d\n",found,sb->sv_block_size,MAJOR(dev),MINOR(dev));
 481         sb->s_magic = SYSV_MAGIC_BASE + sb->sv_type;
 482         /* The buffer code now supports block size 512 as well as 1024. */
 483         sb->s_blocksize = sb->sv_block_size;
 484         sb->s_blocksize_bits = sb->sv_block_size_bits;
 485         /* set up enough so that it can read an inode */
 486         sb->s_dev = dev;
 487         sb->s_op = &sysv_sops;
 488         sb->s_mounted = iget(sb,SYSV_ROOT_INO);
 489         unlock_super(sb);
 490         if (!sb->s_mounted) {
 491                 printk("SysV FS: get root inode failed\n");
 492                 sysv_put_super(sb);
 493                 return NULL;
 494         }
 495         sb->s_dirt = 1;
 496         /* brelse(bh);  resp.  brelse(bh1); brelse(bh2);
 497            occurs when the disk is unmounted. */
 498         return sb;
 499 }
 500 
 501 /* This is only called on sync() and umount(), when s_dirt=1. */
 502 void sysv_write_super (struct super_block *sb)
     /*  */
 503 {
 504         lock_super(sb);
 505         if (sb->sv_bh1->b_dirt || sb->sv_bh2->b_dirt) {
 506                 /* If we are going to write out the super block,
 507                    then attach current time stamp.
 508                    But if the filesystem was marked clean, keep it clean. */
 509                 unsigned long time = CURRENT_TIME;
 510                 unsigned long old_time = *sb->sv_sb_time;
 511                 if (sb->sv_convert)
 512                         old_time = from_coh_ulong(old_time);
 513                 if (sb->sv_type == FSTYPE_SYSV4)
 514                         if (*sb->sv_sb_state == 0x7c269d38 - old_time)
 515                                 *sb->sv_sb_state = 0x7c269d38 - time;
 516                 if (sb->sv_convert)
 517                         time = to_coh_ulong(time);
 518                 *sb->sv_sb_time = time;
 519                 mark_buffer_dirty(sb->sv_bh2, 1);
 520         }
 521         sb->s_dirt = 0;
 522         unlock_super(sb);
 523 }
 524 
 525 void sysv_put_super(struct super_block *sb)
     /*  */
 526 {
 527         /* we can assume sysv_write_super() has already been called */
 528         lock_super(sb);
 529         brelse(sb->sv_bh1);
 530         if (sb->sv_bh1 != sb->sv_bh2) brelse(sb->sv_bh2);
 531         /* switch back to default block size */
 532         if (sb->s_blocksize != BLOCK_SIZE)
 533                 set_blocksize(sb->s_dev,BLOCK_SIZE);
 534         sb->s_dev = 0;
 535         unlock_super(sb);
 536         MOD_DEC_USE_COUNT;
 537 }
 538 
 539 void sysv_statfs(struct super_block *sb, struct statfs *buf, int bufsiz)
     /*  */
 540 {
 541         struct statfs tmp;
 542 
 543         tmp.f_type = sb->s_magic;
 544         tmp.f_bsize = sb->sv_block_size;
 545         tmp.f_blocks = sb->sv_ndatazones;
 546         tmp.f_bfree = sysv_count_free_blocks(sb);
 547         tmp.f_bavail = tmp.f_bfree;
 548         tmp.f_files = sb->sv_ninodes;
 549         tmp.f_ffree = sysv_count_free_inodes(sb);
 550         tmp.f_namelen = SYSV_NAMELEN;
 551         memcpy_tofs(buf, &tmp, bufsiz);
 552 }
 553 
 554 
 555 /* bmap support for running executables and shared libraries. */
 556 
 557 static inline int inode_bmap(struct super_block * sb, struct inode * inode, int nr)
     /*  */
 558 {
 559         int tmp = inode->u.sysv_i.i_data[nr];
 560         if (!tmp)
 561                 return 0;
 562         return tmp + sb->sv_block_base;
 563 }
 564 
 565 static int block_bmap(struct super_block * sb, struct buffer_head * bh, int nr, int convert)
     /*  */
 566 {
 567         int tmp;
 568 
 569         if (!bh)
 570                 return 0;
 571         tmp = ((sysv_zone_t *) bh->b_data) [nr];
 572         if (convert)
 573                 tmp = from_coh_ulong(tmp);
 574         brelse(bh);
 575         if (!tmp)
 576                 return 0;
 577         return tmp + sb->sv_block_base;
 578 }
 579 
 580 int sysv_bmap(struct inode * inode,int block_nr)
     /*  */
 581 {
 582         unsigned int block = block_nr;
 583         struct super_block * sb = inode->i_sb;
 584         int convert;
 585         int i;
 586         struct buffer_head * bh;
 587 
 588         if (block < 10)
 589                 return inode_bmap(sb,inode,block);
 590         block -= 10;
 591         convert = sb->sv_convert;
 592         if (block < sb->sv_ind_per_block) {
 593                 i = inode_bmap(sb,inode,10);
 594                 if (!i)
 595                         return 0;
 596                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 597                 return block_bmap(sb, bh, block, convert);
 598         }
 599         block -= sb->sv_ind_per_block;
 600         if (block < sb->sv_ind_per_block_2) {
 601                 i = inode_bmap(sb,inode,11);
 602                 if (!i)
 603                         return 0;
 604                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 605                 i = block_bmap(sb, bh, block >> sb->sv_ind_per_block_bits, convert);
 606                 if (!i)
 607                         return 0;
 608                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 609                 return block_bmap(sb, bh, block & sb->sv_ind_per_block_1, convert);
 610         }
 611         block -= sb->sv_ind_per_block_2;
 612         if (block < sb->sv_ind_per_block_3) {
 613                 i = inode_bmap(sb,inode,12);
 614                 if (!i)
 615                         return 0;
 616                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 617                 i = block_bmap(sb, bh, block >> sb->sv_ind_per_block_2_bits, convert);
 618                 if (!i)
 619                         return 0;
 620                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 621                 i = block_bmap(sb, bh, (block >> sb->sv_ind_per_block_bits) & sb->sv_ind_per_block_1,convert);
 622                 if (!i)
 623                         return 0;
 624                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 625                 return block_bmap(sb, bh, block & sb->sv_ind_per_block_1, convert);
 626         }
 627         if ((int)block<0) {
 628                 printk("sysv_bmap: block<0");
 629                 return 0;
 630         }
 631         printk("sysv_bmap: block>big");
 632         return 0;
 633 }
 634 
 635 /* End of bmap support. */
 636 
 637 
 638 /* Access selected blocks of regular files (or directories) */
 639 
 640 static struct buffer_head * inode_getblk(struct inode * inode, int nr, int create)
     /*  */
 641 {
 642         struct super_block *sb;
 643         unsigned long tmp;
 644         unsigned long *p;
 645         struct buffer_head * result;
 646 
 647         sb = inode->i_sb;
 648         p = inode->u.sysv_i.i_data + nr;
 649 repeat:
 650         tmp = *p;
 651         if (tmp) {
 652                 result = sv_getblk(sb, inode->i_dev, tmp);
 653                 if (tmp == *p)
 654                         return result;
 655                 brelse(result);
 656                 goto repeat;
 657         }
 658         if (!create)
 659                 return NULL;
 660         tmp = sysv_new_block(sb);
 661         if (!tmp)
 662                 return NULL;
 663         result = sv_getblk(sb, inode->i_dev, tmp);
 664         if (*p) {
 665                 sysv_free_block(sb,tmp);
 666                 brelse(result);
 667                 goto repeat;
 668         }
 669         *p = tmp;
 670         inode->i_ctime = CURRENT_TIME;
 671         inode->i_dirt = 1;
 672         return result;
 673 }
 674 
 675 static struct buffer_head * block_getblk(struct inode * inode, 
     /*  */
 676         struct buffer_head * bh, int nr, int create)
 677 {
 678         struct super_block *sb;
 679         unsigned long tmp, block;
 680         sysv_zone_t *p;
 681         struct buffer_head * result;
 682 
 683         if (!bh)
 684                 return NULL;
 685         if (!bh->b_uptodate) {
 686                 ll_rw_block(READ, 1, &bh);
 687                 wait_on_buffer(bh);
 688                 if (!bh->b_uptodate) {
 689                         brelse(bh);
 690                         return NULL;
 691                 }
 692         }
 693         sb = inode->i_sb;
 694         p = nr + (sysv_zone_t *) bh->b_data;
 695 repeat:
 696         block = tmp = *p;
 697         if (sb->sv_convert)
 698                 block = from_coh_ulong(block);
 699         if (tmp) {
 700                 result = sv_getblk(sb, bh->b_dev, block);
 701                 if (tmp == *p) {
 702                         brelse(bh);
 703                         return result;
 704                 }
 705                 brelse(result);
 706                 goto repeat;
 707         }
 708         if (!create) {
 709                 brelse(bh);
 710                 return NULL;
 711         }
 712         block = sysv_new_block(sb);
 713         if (!block) {
 714                 brelse(bh);
 715                 return NULL;
 716         }
 717         result = sv_getblk(sb, bh->b_dev, block);
 718         if (*p) {
 719                 sysv_free_block(sb,block);
 720                 brelse(result);
 721                 goto repeat;
 722         }
 723         *p = (sb->sv_convert ? to_coh_ulong(block) : block);
 724         mark_buffer_dirty(bh, 1);
 725         brelse(bh);
 726         return result;
 727 }
 728 
 729 struct buffer_head * sysv_getblk(struct inode * inode, unsigned int block, int create)
     /*  */
 730 {
 731         struct super_block * sb = inode->i_sb;
 732         struct buffer_head * bh;
 733 
 734         if (block < 10)
 735                 return inode_getblk(inode,block,create);
 736         block -= 10;
 737         if (block < sb->sv_ind_per_block) {
 738                 bh = inode_getblk(inode,10,create);
 739                 return block_getblk(inode, bh, block, create);
 740         }
 741         block -= sb->sv_ind_per_block;
 742         if (block < sb->sv_ind_per_block_2) {
 743                 bh = inode_getblk(inode,11,create);
 744                 bh = block_getblk(inode, bh, block >> sb->sv_ind_per_block_bits, create);
 745                 return block_getblk(inode, bh, block & sb->sv_ind_per_block_1, create);
 746         }
 747         block -= sb->sv_ind_per_block_2;
 748         if (block < sb->sv_ind_per_block_3) {
 749                 bh = inode_getblk(inode,12,create);
 750                 bh = block_getblk(inode, bh, block >> sb->sv_ind_per_block_2_bits, create);
 751                 bh = block_getblk(inode, bh, (block >> sb->sv_ind_per_block_bits) & sb->sv_ind_per_block_1, create);
 752                 return block_getblk(inode, bh, block & sb->sv_ind_per_block_1, create);
 753         }
 754         if ((int)block<0) {
 755                 printk("sysv_getblk: block<0");
 756                 return NULL;
 757         }
 758         printk("sysv_getblk: block>big");
 759         return NULL;
 760 }
 761 
 762 struct buffer_head * sysv_file_bread(struct inode * inode, int block, int create)
     /*  */
 763 {
 764         struct buffer_head * bh;
 765 
 766         bh = sysv_getblk(inode,block,create);
 767         if (!bh || bh->b_uptodate)
 768                 return bh;
 769         ll_rw_block(READ, 1, &bh);
 770         wait_on_buffer(bh);
 771         if (bh->b_uptodate)
 772                 return bh;
 773         brelse(bh);
 774         return NULL;
 775 }
 776 
 777 
 778 static inline unsigned long read3byte (char * p)
     /*  */
 779 {
 780         return (unsigned long)(*(unsigned short *)p)
 781              | (unsigned long)(*(unsigned char *)(p+2)) << 16;
 782 }
 783 
 784 static inline void write3byte (char * p, unsigned long val)
     /*  */
 785 {
 786         *(unsigned short *)p = (unsigned short) val;
 787         *(unsigned char *)(p+2) = val >> 16;
 788 }
 789 
 790 static inline unsigned long coh_read3byte (char * p)
     /*  */
 791 {
 792         return (unsigned long)(*(unsigned char *)p) << 16
 793              | (unsigned long)(*(unsigned short *)(p+1));
 794 }
 795 
 796 static inline void coh_write3byte (char * p, unsigned long val)
     /*  */
 797 {
 798         *(unsigned char *)p = val >> 16;
 799         *(unsigned short *)(p+1) = (unsigned short) val;
 800 }
 801 
 802 void sysv_read_inode(struct inode * inode)
     /*  */
 803 {
 804         struct super_block * sb = inode->i_sb;
 805         struct buffer_head * bh;
 806         struct sysv_inode * raw_inode;
 807         unsigned int block, ino;
 808         umode_t mode;
 809 
 810         ino = inode->i_ino;
 811         inode->i_op = NULL;
 812         inode->i_mode = 0;
 813         if (!ino || ino > sb->sv_ninodes) {
 814                 printk("Bad inode number on dev 0x%04x: %d is out of range\n",
 815                         inode->i_dev, ino);
 816                 return;
 817         }
 818         block = sb->sv_firstinodezone + ((ino-1) >> sb->sv_inodes_per_block_bits);
 819         if (!(bh = sv_bread(sb,inode->i_dev,block))) {
 820                 printk("Major problem: unable to read inode from dev 0x%04x\n",
 821                         inode->i_dev);
 822                 return;
 823         }
 824         raw_inode = (struct sysv_inode *) bh->b_data + ((ino-1) & sb->sv_inodes_per_block_1);
 825         mode = raw_inode->i_mode;
 826         if (sb->sv_kludge_symlinks)
 827                 mode = from_coh_imode(mode);
 828         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 829         inode->i_mode = mode;
 830         inode->i_uid = raw_inode->i_uid;
 831         inode->i_gid = raw_inode->i_gid;
 832         inode->i_nlink = raw_inode->i_nlink;
 833         if (sb->sv_convert) {
 834                 inode->i_size = from_coh_ulong(raw_inode->i_size);
 835                 inode->i_atime = from_coh_ulong(raw_inode->i_atime);
 836                 inode->i_mtime = from_coh_ulong(raw_inode->i_mtime);
 837                 inode->i_ctime = from_coh_ulong(raw_inode->i_ctime);
 838         } else {
 839                 inode->i_size = raw_inode->i_size;
 840                 inode->i_atime = raw_inode->i_atime;
 841                 inode->i_mtime = raw_inode->i_mtime;
 842                 inode->i_ctime = raw_inode->i_ctime;
 843         }
 844         inode->i_blocks = inode->i_blksize = 0;
 845         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 846                 inode->i_rdev = raw_inode->i_a.i_rdev;
 847         else
 848         if (sb->sv_convert)
 849                 for (block = 0; block < 10+1+1+1; block++)
 850                         inode->u.sysv_i.i_data[block] =
 851                                 coh_read3byte(&raw_inode->i_a.i_addb[3*block]);
 852         else
 853                 for (block = 0; block < 10+1+1+1; block++)
 854                         inode->u.sysv_i.i_data[block] =
 855                                 read3byte(&raw_inode->i_a.i_addb[3*block]);
 856         brelse(bh);
 857         if (S_ISREG(inode->i_mode))
 858                 inode->i_op = &sysv_file_inode_operations;
 859         else if (S_ISDIR(inode->i_mode))
 860                 inode->i_op = &sysv_dir_inode_operations;
 861         else if (S_ISLNK(inode->i_mode))
 862                 inode->i_op = &sysv_symlink_inode_operations;
 863         else if (S_ISCHR(inode->i_mode))
 864                 inode->i_op = &chrdev_inode_operations;
 865         else if (S_ISBLK(inode->i_mode))
 866                 inode->i_op = &blkdev_inode_operations;
 867         else if (S_ISFIFO(inode->i_mode))
 868                 init_fifo(inode);
 869 }
 870 
 871 /* To avoid inconsistencies between inodes in memory and inodes on disk. */
 872 extern int sysv_notify_change(struct inode *inode, struct iattr *attr)
     /*  */
 873 {
 874         int error;
 875 
 876         if ((error = inode_change_ok(inode, attr)) != 0)
 877                 return error;
 878 
 879         if (attr->ia_valid & ATTR_MODE)
 880                 if (inode->i_sb->sv_kludge_symlinks)
 881                         if (attr->ia_mode == COH_KLUDGE_SYMLINK_MODE)
 882                                 attr->ia_mode = COH_KLUDGE_NOT_SYMLINK;
 883 
 884         inode_setattr(inode, attr);
 885 
 886         return 0;
 887 }
 888 
 889 static struct buffer_head * sysv_update_inode(struct inode * inode)
     /*  */
 890 {
 891         struct super_block * sb = inode->i_sb;
 892         struct buffer_head * bh;
 893         struct sysv_inode * raw_inode;
 894         unsigned int ino, block;
 895         umode_t mode;
 896 
 897         ino = inode->i_ino;
 898         if (!ino || ino > sb->sv_ninodes) {
 899                 printk("Bad inode number on dev 0x%04x: %d is out of range\n",
 900                         inode->i_dev, ino);
 901                 inode->i_dirt = 0;
 902                 return 0;
 903         }
 904         block = sb->sv_firstinodezone + ((ino-1) >> sb->sv_inodes_per_block_bits);
 905         if (!(bh = sv_bread(sb,inode->i_dev,block))) {
 906                 printk("unable to read i-node block\n");
 907                 inode->i_dirt = 0;
 908                 return 0;
 909         }
 910         raw_inode = (struct sysv_inode *) bh->b_data + ((ino-1) & sb->sv_inodes_per_block_1);
 911         mode = inode->i_mode;
 912         if (sb->sv_kludge_symlinks)
 913                 mode = to_coh_imode(mode);
 914         raw_inode->i_mode = mode;
 915         raw_inode->i_uid = inode->i_uid;
 916         raw_inode->i_gid = inode->i_gid;
 917         raw_inode->i_nlink = inode->i_nlink;
 918         if (sb->sv_convert) {
 919                 raw_inode->i_size = to_coh_ulong(inode->i_size);
 920                 raw_inode->i_atime = to_coh_ulong(inode->i_atime);
 921                 raw_inode->i_mtime = to_coh_ulong(inode->i_mtime);
 922                 raw_inode->i_ctime = to_coh_ulong(inode->i_ctime);
 923         } else {
 924                 raw_inode->i_size = inode->i_size;
 925                 raw_inode->i_atime = inode->i_atime;
 926                 raw_inode->i_mtime = inode->i_mtime;
 927                 raw_inode->i_ctime = inode->i_ctime;
 928         }
 929         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 930                 raw_inode->i_a.i_rdev = inode->i_rdev; /* write 2 or 3 bytes ?? */
 931         else
 932         if (sb->sv_convert)
 933                 for (block = 0; block < 10+1+1+1; block++)
 934                         coh_write3byte(&raw_inode->i_a.i_addb[3*block],inode->u.sysv_i.i_data[block]);
 935         else
 936                 for (block = 0; block < 10+1+1+1; block++)
 937                         write3byte(&raw_inode->i_a.i_addb[3*block],inode->u.sysv_i.i_data[block]);
 938         inode->i_dirt=0;
 939         mark_buffer_dirty(bh, 1);
 940         return bh;
 941 }
 942 
 943 void sysv_write_inode(struct inode * inode)
     /*  */
 944 {
 945         struct buffer_head *bh;
 946         bh = sysv_update_inode(inode);
 947         brelse(bh);
 948 }
 949 
 950 int sysv_sync_inode(struct inode * inode)
     /*  */
 951 {
 952         int err = 0;
 953         struct buffer_head *bh;
 954 
 955         bh = sysv_update_inode(inode);
 956         if (bh && bh->b_dirt) {
 957                 ll_rw_block(WRITE, 1, &bh);
 958                 wait_on_buffer(bh);
 959                 if (bh->b_req && !bh->b_uptodate)
 960                 {
 961                         printk ("IO error syncing sysv inode [%04x:%08lx]\n",
 962                                 inode->i_dev, inode->i_ino);
 963                         err = -1;
 964                 }
 965         }
 966         else if (!bh)
 967                 err = -1;
 968         brelse (bh);
 969         return err;
 970 }
 971 
 972 #ifdef MODULE
 973 
 974 /* Every kernel module contains stuff like this. */
 975 
 976 char kernel_version[] = UTS_RELEASE;
 977 
 978 static struct file_system_type sysv_fs_type[3] = {
 979         {sysv_read_super, "xenix", 1, NULL},
 980         {sysv_read_super, "sysv", 1, NULL},
 981         {sysv_read_super, "coherent", 1, NULL}
 982 };
 983 
 984 int init_module(void)
     /*  */
 985 {
 986         int i;
 987 
 988         for (i = 0; i < 3; i++)
 989                 register_filesystem(&sysv_fs_type[i]);
 990 
 991         return 0;
 992 }
 993 
 994 void cleanup_module(void)
     /*  */
 995 {
 996         int i;
 997 
 998         for (i = 0; i < 3; i++)
 999                 unregister_filesystem(&sysv_fs_type[i]);
1000 }
1001 
1002 #endif
/* */
root/fs/sysv/inode.c

DEFINITIONS
