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 #include <linux/module.h>
  24 
  25 #include <linux/sched.h>
  26 #include <linux/kernel.h>
  27 #include <linux/fs.h>
  28 #include <linux/sysv_fs.h>
  29 #include <linux/stat.h>
  30 #include <linux/string.h>
  31 #include <linux/locks.h>
  32 
  33 #include <asm/segment.h>
  34 
  35 void sysv_put_inode(struct inode *inode)
     /*  */
  36 {
  37         if (inode->i_nlink)
  38                 return;
  39         inode->i_size = 0;
  40         sysv_truncate(inode);
  41         sysv_free_inode(inode);
  42 }
  43 
  44 
  45 static struct super_operations sysv_sops = { 
  46         sysv_read_inode,
  47         sysv_notify_change,
  48         sysv_write_inode,
  49         sysv_put_inode,
  50         sysv_put_super,
  51         sysv_write_super,
  52         sysv_statfs,
  53         NULL
  54 };
  55 
  56 /* The following functions try to recognize specific filesystems.
  57  * We recognize:
  58  * - Xenix FS by its magic number.
  59  * - SystemV FS by its magic number.
  60  * - Coherent FS by its funny fname/fpack field.
  61  * We discriminate among SystemV4 and SystemV2 FS by the assumption that
  62  * the time stamp is not < 01-01-1980.
  63  */
  64 
  65 static void detected_bs512 (struct super_block *sb)
     /*  */
  66 {
  67         sb->sv_block_size = 512;
  68         sb->sv_block_size_1 = 512-1;
  69         sb->sv_block_size_bits = 9;
  70         sb->sv_block_size_ratio = 2;
  71         sb->sv_block_size_ratio_bits = 1;
  72         sb->sv_inodes_per_block = 512/64;
  73         sb->sv_inodes_per_block_1 = 512/64-1;
  74         sb->sv_inodes_per_block_bits = 9-6;
  75         sb->sv_toobig_block = 10 + 
  76           (sb->sv_ind_per_block = 512/4) +
  77           (sb->sv_ind_per_block_2 = (512/4)*(512/4)) +
  78           (sb->sv_ind_per_block_3 = (512/4)*(512/4)*(512/4));
  79         sb->sv_ind_per_block_1 = 512/4-1;
  80         sb->sv_ind_per_block_2_1 = (512/4)*(512/4)-1;
  81         sb->sv_ind_per_block_2_bits = 2 *
  82           (sb->sv_ind_per_block_bits = 9-2);
  83         sb->sv_ind_per_block_block_size_1 = (512/4)*512-1;
  84         sb->sv_ind_per_block_block_size_bits = (9-2)+9;
  85         sb->sv_ind_per_block_2_block_size_1 = (512/4)*(512/4)*512-1;
  86         sb->sv_ind_per_block_2_block_size_bits = (9-2)+(9-2)+9;
  87         sb->sv_ind0_size = 10 * 512;
  88         sb->sv_ind1_size = (10 + (512/4))* 512;
  89         sb->sv_ind2_size = (10 + (512/4) + (512/4)*(512/4)) * 512;
  90 }
  91 
  92 static void detected_bs1024 (struct super_block *sb)
     /*  */
  93 {
  94         sb->sv_block_size = 1024;
  95         sb->sv_block_size_1 = 1024-1;
  96         sb->sv_block_size_bits = 10;
  97         sb->sv_block_size_ratio = 1;
  98         sb->sv_block_size_ratio_bits = 0;
  99         sb->sv_inodes_per_block = 1024/64;
 100         sb->sv_inodes_per_block_1 = 1024/64-1;
 101         sb->sv_inodes_per_block_bits = 10-6;
 102         sb->sv_toobig_block = 10 + 
 103           (sb->sv_ind_per_block = 1024/4) +
 104           (sb->sv_ind_per_block_2 = (1024/4)*(1024/4)) +
 105           (sb->sv_ind_per_block_3 = (1024/4)*(1024/4)*(1024/4));
 106         sb->sv_ind_per_block_1 = 1024/4-1;
 107         sb->sv_ind_per_block_2_1 = (1024/4)*(1024/4)-1;
 108         sb->sv_ind_per_block_2_bits = 2 *
 109           (sb->sv_ind_per_block_bits = 10-2);
 110         sb->sv_ind_per_block_block_size_1 = (1024/4)*1024-1;
 111         sb->sv_ind_per_block_block_size_bits = (10-2)+10;
 112         sb->sv_ind_per_block_2_block_size_1 = (1024/4)*(1024/4)*1024-1;
 113         sb->sv_ind_per_block_2_block_size_bits = (10-2)+(10-2)+10;
 114         sb->sv_ind0_size = 10 * 1024;
 115         sb->sv_ind1_size = (10 + (1024/4))* 1024;
 116         sb->sv_ind2_size = (10 + (1024/4) + (1024/4)*(1024/4)) * 1024;
 117 }
 118 
 119 static const char* detect_xenix (struct super_block *sb, struct buffer_head *bh)
     /*  */
 120 {
 121         struct xenix_super_block * sbd;
 122 
 123         sbd = (struct xenix_super_block *) bh->b_data;
 124         if (sbd->s_magic != 0x2b5544)
 125                 return NULL;
 126         switch (sbd->s_type) {
 127                 case 1: detected_bs512(sb); break;
 128                 case 2: detected_bs1024(sb); break;
 129                 default: return NULL;
 130         }
 131         sb->sv_type = FSTYPE_XENIX;
 132         return "Xenix";
 133 }
 134 static struct super_block * detected_xenix (struct super_block *sb, struct buffer_head *bh1, struct buffer_head *bh2)
     /*  */
 135 {
 136         struct xenix_super_block * sbd1;
 137         struct xenix_super_block * sbd2;
 138 
 139         if (sb->sv_block_size == BLOCK_SIZE)
 140                 /* block size = 1024, so bh1 = bh2 */
 141                 sbd1 = sbd2 = (struct xenix_super_block *) bh1->b_data;
 142         else {
 143                 /* block size = 512, so bh1 != bh2 */
 144                 sbd1 = (struct xenix_super_block *) bh1->b_data;
 145                 sbd2 = (struct xenix_super_block *) (bh2->b_data - BLOCK_SIZE/2);
 146                 /* sanity check */
 147                 if (sbd2->s_magic != 0x2b5544)
 148                         return NULL;
 149         }
 150 
 151         sb->sv_convert = 0;
 152         sb->sv_kludge_symlinks = 1;
 153         sb->sv_truncate = 1;
 154         sb->sv_link_max = XENIX_LINK_MAX;
 155         sb->sv_fic_size = XENIX_NICINOD;
 156         sb->sv_flc_size = XENIX_NICFREE;
 157         sb->sv_bh1 = bh1;
 158         sb->sv_bh2 = bh2;
 159         sb->sv_sbd1 = (char *) sbd1;
 160         sb->sv_sbd2 = (char *) sbd2;
 161         sb->sv_sb_fic_count = &sbd1->s_ninode;
 162         sb->sv_sb_fic_inodes = &sbd1->s_inode[0];
 163         sb->sv_sb_total_free_inodes = &sbd2->s_tinode;
 164         sb->sv_sb_flc_count = &sbd1->s_nfree;
 165         sb->sv_sb_flc_blocks = &sbd1->s_free[0];
 166         sb->sv_sb_total_free_blocks = &sbd2->s_tfree;
 167         sb->sv_sb_time = &sbd2->s_time;
 168         sb->sv_block_base = 0;
 169         sb->sv_firstinodezone = 2;
 170         sb->sv_firstdatazone = sbd1->s_isize;
 171         sb->sv_nzones = sbd1->s_fsize;
 172         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 173         return sb;
 174 }
 175 
 176 static const char* detect_sysv4 (struct super_block *sb, struct buffer_head *bh)
     /*  */
 177 {
 178         struct sysv4_super_block * sbd;
 179 
 180         sbd = (struct sysv4_super_block *) (bh->b_data + BLOCK_SIZE/2);
 181         if (sbd->s_magic != 0xfd187e20)
 182                 return NULL;
 183         if (sbd->s_time < 315532800) /* this is likely to happen on SystemV2 FS */
 184                 return NULL;
 185         switch (sbd->s_type) {
 186                 case 1: detected_bs512(sb); break;
 187                 case 2: detected_bs1024(sb); break;
 188                 default: return NULL;
 189         }
 190         sb->sv_type = FSTYPE_SYSV4;
 191         return "SystemV";
 192 }
 193 static struct super_block * detected_sysv4 (struct super_block *sb, struct buffer_head *bh)
     /*  */
 194 {
 195         struct sysv4_super_block * sbd;
 196 
 197         if (sb->sv_block_size == BLOCK_SIZE)
 198                 sbd = (struct sysv4_super_block *) (bh->b_data + BLOCK_SIZE/2);
 199         else {
 200                 sbd = (struct sysv4_super_block *) bh->b_data;
 201                 /* sanity check */
 202                 if (sbd->s_magic != 0xfd187e20)
 203                         return NULL;
 204                 if (sbd->s_time < 315532800)
 205                         return NULL;
 206         }
 207 
 208         sb->sv_convert = 0;
 209         sb->sv_kludge_symlinks = 0; /* ?? */
 210         sb->sv_truncate = 1;
 211         sb->sv_link_max = SYSV_LINK_MAX;
 212         sb->sv_fic_size = SYSV_NICINOD;
 213         sb->sv_flc_size = SYSV_NICFREE;
 214         sb->sv_bh1 = bh;
 215         sb->sv_bh2 = bh;
 216         sb->sv_sbd1 = (char *) sbd;
 217         sb->sv_sbd2 = (char *) sbd;
 218         sb->sv_sb_fic_count = &sbd->s_ninode;
 219         sb->sv_sb_fic_inodes = &sbd->s_inode[0];
 220         sb->sv_sb_total_free_inodes = &sbd->s_tinode;
 221         sb->sv_sb_flc_count = &sbd->s_nfree;
 222         sb->sv_sb_flc_blocks = &sbd->s_free[0];
 223         sb->sv_sb_total_free_blocks = &sbd->s_tfree;
 224         sb->sv_sb_time = &sbd->s_time;
 225         sb->sv_sb_state = &sbd->s_state;
 226         sb->sv_block_base = 0;
 227         sb->sv_firstinodezone = 2;
 228         sb->sv_firstdatazone = sbd->s_isize;
 229         sb->sv_nzones = sbd->s_fsize;
 230         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 231         return sb;
 232 }
 233 
 234 static const char* detect_sysv2 (struct super_block *sb, struct buffer_head *bh)
     /*  */
 235 {
 236         struct sysv2_super_block * sbd;
 237 
 238         sbd = (struct sysv2_super_block *) (bh->b_data + BLOCK_SIZE/2);
 239         if (sbd->s_magic != 0xfd187e20)
 240                 return NULL;
 241         if (sbd->s_time < 315532800) /* this is likely to happen on SystemV4 FS */
 242                 return NULL;
 243         switch (sbd->s_type) {
 244                 case 1: detected_bs512(sb); break;
 245                 case 2: detected_bs1024(sb); break;
 246                 default: return NULL;
 247         }
 248         sb->sv_type = FSTYPE_SYSV2;
 249         return "SystemV Release 2";
 250 }
 251 static struct super_block * detected_sysv2 (struct super_block *sb, struct buffer_head *bh)
     /*  */
 252 {
 253         struct sysv2_super_block * sbd;
 254 
 255         if (sb->sv_block_size == BLOCK_SIZE)
 256                 sbd = (struct sysv2_super_block *) (bh->b_data + BLOCK_SIZE/2);
 257         else {
 258                 sbd = (struct sysv2_super_block *) bh->b_data;
 259                 /* sanity check */
 260                 if (sbd->s_magic != 0xfd187e20)
 261                         return NULL;
 262                 if (sbd->s_time < 315532800)
 263                         return NULL;
 264         }
 265 
 266         sb->sv_convert = 0;
 267         sb->sv_kludge_symlinks = 0; /* ?? */
 268         sb->sv_truncate = 1;
 269         sb->sv_link_max = SYSV_LINK_MAX;
 270         sb->sv_fic_size = SYSV_NICINOD;
 271         sb->sv_flc_size = SYSV_NICFREE;
 272         sb->sv_bh1 = bh;
 273         sb->sv_bh2 = bh;
 274         sb->sv_sbd1 = (char *) sbd;
 275         sb->sv_sbd2 = (char *) sbd;
 276         sb->sv_sb_fic_count = &sbd->s_ninode;
 277         sb->sv_sb_fic_inodes = &sbd->s_inode[0];
 278         sb->sv_sb_total_free_inodes = &sbd->s_tinode;
 279         sb->sv_sb_flc_count = &sbd->s_nfree;
 280         sb->sv_sb_flc_blocks = &sbd->s_free[0];
 281         sb->sv_sb_total_free_blocks = &sbd->s_tfree;
 282         sb->sv_sb_time = &sbd->s_time;
 283         sb->sv_sb_state = &sbd->s_state;
 284         sb->sv_block_base = 0;
 285         sb->sv_firstinodezone = 2;
 286         sb->sv_firstdatazone = sbd->s_isize;
 287         sb->sv_nzones = sbd->s_fsize;
 288         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 289         return sb;
 290 }
 291 
 292 static const char* detect_coherent (struct super_block *sb, struct buffer_head *bh)
     /*  */
 293 {
 294         struct coh_super_block * sbd;
 295 
 296         sbd = (struct coh_super_block *) (bh->b_data + BLOCK_SIZE/2);
 297         if ((memcmp(sbd->s_fname,"noname",6) && memcmp(sbd->s_fname,"xxxxx ",6))
 298             || (memcmp(sbd->s_fpack,"nopack",6) && memcmp(sbd->s_fpack,"xxxxx\n",6)))
 299                 return NULL;
 300         detected_bs512(sb);
 301         sb->sv_type = FSTYPE_COH;
 302         return "Coherent";
 303 }
 304 static struct super_block * detected_coherent (struct super_block *sb, struct buffer_head *bh)
     /*  */
 305 {
 306         struct coh_super_block * sbd;
 307 
 308         sbd = (struct coh_super_block *) bh->b_data;
 309         /* sanity check */
 310         if ((memcmp(sbd->s_fname,"noname",6) && memcmp(sbd->s_fname,"xxxxx ",6))
 311             || (memcmp(sbd->s_fpack,"nopack",6) && memcmp(sbd->s_fpack,"xxxxx\n",6)))
 312                 return NULL;
 313 
 314         sb->sv_convert = 1;
 315         sb->sv_kludge_symlinks = 1;
 316         sb->sv_truncate = 1;
 317         sb->sv_link_max = COH_LINK_MAX;
 318         sb->sv_fic_size = COH_NICINOD;
 319         sb->sv_flc_size = COH_NICFREE;
 320         sb->sv_bh1 = bh;
 321         sb->sv_bh2 = bh;
 322         sb->sv_sbd1 = (char *) sbd;
 323         sb->sv_sbd2 = (char *) sbd;
 324         sb->sv_sb_fic_count = &sbd->s_ninode;
 325         sb->sv_sb_fic_inodes = &sbd->s_inode[0];
 326         sb->sv_sb_total_free_inodes = &sbd->s_tinode;
 327         sb->sv_sb_flc_count = &sbd->s_nfree;
 328         sb->sv_sb_flc_blocks = &sbd->s_free[0];
 329         sb->sv_sb_total_free_blocks = &sbd->s_tfree;
 330         sb->sv_sb_time = &sbd->s_time;
 331         sb->sv_block_base = 0;
 332         sb->sv_firstinodezone = 2;
 333         sb->sv_firstdatazone = sbd->s_isize;
 334         sb->sv_nzones = from_coh_ulong(sbd->s_fsize);
 335         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 336         return sb;
 337 }
 338 
 339 struct super_block *sysv_read_super(struct super_block *sb,void *data, 
     /*  */
 340                                      int silent)
 341 {
 342         struct buffer_head *bh;
 343         const char *found;
 344         kdev_t dev = sb->s_dev;
 345 
 346         if (1024 != sizeof (struct xenix_super_block))
 347                 panic("Xenix FS: bad super-block size");
 348         if ((512 != sizeof (struct sysv4_super_block))
 349             || (512 != sizeof (struct sysv2_super_block)))
 350                 panic("SystemV FS: bad super-block size");
 351         if (500 != sizeof (struct coh_super_block))
 352                 panic("Coherent FS: bad super-block size");
 353         if (64 != sizeof (struct sysv_inode))
 354                 panic("sysv fs: bad i-node size");
 355         MOD_INC_USE_COUNT;
 356         lock_super(sb);
 357         set_blocksize(dev,BLOCK_SIZE);
 358 
 359         /* Try to read Xenix superblock */
 360         if ((bh = bread(dev, 1, BLOCK_SIZE)) != NULL) {
 361                 if ((found = detect_xenix(sb,bh)) != NULL)
 362                         goto ok;
 363                 brelse(bh);
 364         }
 365         if ((bh = bread(dev, 0, BLOCK_SIZE)) != NULL) {
 366                 /* Try to recognize SystemV superblock */
 367                 if ((found = detect_sysv4(sb,bh)) != NULL)
 368                         goto ok;
 369                 if ((found = detect_sysv2(sb,bh)) != NULL)
 370                         goto ok;
 371                 /* Try to recognize Coherent superblock */
 372                 if ((found = detect_coherent(sb,bh)) != NULL)
 373                         goto ok;
 374                 brelse(bh);
 375         }
 376         /* Try to recognize SystemV superblock */
 377         /* Offset by 1 track, i.e. most probably 9, 15, or 18 kilobytes. */
 378         {       static int offsets[] = { 9, 15, 18, };
 379                 int i;
 380                 for (i = 0; i < sizeof(offsets)/sizeof(offsets[0]); i++)
 381                         if ((bh = bread(dev, offsets[i], BLOCK_SIZE)) != NULL) {
 382                                 /* Try to recognize SystemV superblock */
 383                                 if ((found = detect_sysv4(sb,bh)) != NULL) {
 384                                         sb->sv_block_base = offsets[i] << sb->sv_block_size_ratio_bits;
 385                                         goto ok;
 386                                 }
 387                                 if ((found = detect_sysv2(sb,bh)) != NULL) {
 388                                         sb->sv_block_base = offsets[i] << sb->sv_block_size_ratio_bits;
 389                                         goto ok;
 390                                 }
 391                                 brelse(bh);
 392                         }
 393         }
 394         sb->s_dev = 0;
 395         unlock_super(sb);
 396         if (!silent)
 397                 printk("VFS: unable to read Xenix/SystemV/Coherent superblock on device "
 398                        "%s\n", kdevname(dev));
 399         failed:
 400         MOD_DEC_USE_COUNT;
 401         return NULL;
 402 
 403         ok:
 404         if (sb->sv_block_size == BLOCK_SIZE) {
 405                 switch (sb->sv_type) {
 406                         case FSTYPE_XENIX:
 407                                 if (!detected_xenix(sb,bh,bh))
 408                                         goto bad_superblock;
 409                                 break;
 410                         case FSTYPE_SYSV4:
 411                                 if (!detected_sysv4(sb,bh))
 412                                         goto bad_superblock;
 413                                 break;
 414                         case FSTYPE_SYSV2:
 415                                 if (!detected_sysv2(sb,bh))
 416                                         goto bad_superblock;
 417                                 break;
 418                         default:
 419                         bad_superblock:
 420                                 brelse(bh);
 421                                 sb->s_dev = 0;
 422                                 unlock_super(sb);
 423                                 printk("SysV FS: cannot read superblock in 1024 byte mode\n");
 424                                 goto failed;
 425                 }
 426         } else {
 427                 /* Switch to another block size. Unfortunately, we have to
 428                    release the 1 KB block bh and read it in two parts again. */
 429                 struct buffer_head *bh1, *bh2;
 430                 unsigned long blocknr = bh->b_blocknr << sb->sv_block_size_ratio_bits;
 431 
 432                 brelse(bh);
 433                 set_blocksize(dev,sb->sv_block_size);
 434                 bh1 = NULL; bh2 = NULL;
 435                 switch (sb->sv_type) {
 436                         case FSTYPE_XENIX:
 437                                 if ((bh1 = bread(dev, blocknr, sb->sv_block_size)) == NULL)
 438                                         goto bad_superblock2;
 439                                 if ((bh2 = bread(dev, blocknr+1, sb->sv_block_size)) == NULL)
 440                                         goto bad_superblock2;
 441                                 if (!detected_xenix(sb,bh1,bh2))
 442                                         goto bad_superblock2;
 443                                 break;
 444                         case FSTYPE_SYSV4:
 445                                 if ((bh2 = bread(dev, blocknr+1, sb->sv_block_size)) == NULL)
 446                                         goto bad_superblock2;
 447                                 if (!detected_sysv4(sb,bh2))
 448                                         goto bad_superblock2;
 449                                 break;
 450                         case FSTYPE_SYSV2:
 451                                 if ((bh2 = bread(dev, blocknr+1, sb->sv_block_size)) == NULL)
 452                                         goto bad_superblock2;
 453                                 if (!detected_sysv2(sb,bh2))
 454                                         goto bad_superblock2;
 455                                 break;
 456                         case FSTYPE_COH:
 457                                 if ((bh2 = bread(dev, blocknr+1, sb->sv_block_size)) == NULL)
 458                                         goto bad_superblock2;
 459                                 if (!detected_coherent(sb,bh2))
 460                                         goto bad_superblock2;
 461                                 break;
 462                         default:
 463                         bad_superblock2:
 464                                 brelse(bh1);
 465                                 brelse(bh2);
 466                                 set_blocksize(sb->s_dev,BLOCK_SIZE);
 467                                 sb->s_dev = 0;
 468                                 unlock_super(sb);
 469                                 printk("SysV FS: cannot read superblock in 512 byte mode\n");
 470                                 goto failed;
 471                 }
 472         }
 473         sb->sv_ninodes = (sb->sv_firstdatazone - sb->sv_firstinodezone) << sb->sv_inodes_per_block_bits;
 474         if (!silent)
 475                 printk("VFS: Found a %s FS (block size = %d) on device %s\n",
 476                        found, sb->sv_block_size, kdevname(dev));
 477         sb->s_magic = SYSV_MAGIC_BASE + sb->sv_type;
 478         /* The buffer code now supports block size 512 as well as 1024. */
 479         sb->s_blocksize = sb->sv_block_size;
 480         sb->s_blocksize_bits = sb->sv_block_size_bits;
 481         /* set up enough so that it can read an inode */
 482         sb->s_dev = dev;
 483         sb->s_op = &sysv_sops;
 484         sb->s_mounted = iget(sb,SYSV_ROOT_INO);
 485         unlock_super(sb);
 486         if (!sb->s_mounted) {
 487                 printk("SysV FS: get root inode failed\n");
 488                 sysv_put_super(sb);
 489                 return NULL;
 490         }
 491         sb->s_dirt = 1;
 492         /* brelse(bh);  resp.  brelse(bh1); brelse(bh2);
 493            occurs when the disk is unmounted. */
 494         return sb;
 495 }
 496 
 497 /* This is only called on sync() and umount(), when s_dirt=1. */
 498 void sysv_write_super (struct super_block *sb)
     /*  */
 499 {
 500         lock_super(sb);
 501         if (sb->sv_bh1->b_dirt || sb->sv_bh2->b_dirt) {
 502                 /* If we are going to write out the super block,
 503                    then attach current time stamp.
 504                    But if the filesystem was marked clean, keep it clean. */
 505                 unsigned long time = CURRENT_TIME;
 506                 unsigned long old_time = *sb->sv_sb_time;
 507                 if (sb->sv_convert)
 508                         old_time = from_coh_ulong(old_time);
 509                 if (sb->sv_type == FSTYPE_SYSV4)
 510                         if (*sb->sv_sb_state == 0x7c269d38 - old_time)
 511                                 *sb->sv_sb_state = 0x7c269d38 - time;
 512                 if (sb->sv_convert)
 513                         time = to_coh_ulong(time);
 514                 *sb->sv_sb_time = time;
 515                 mark_buffer_dirty(sb->sv_bh2, 1);
 516         }
 517         sb->s_dirt = 0;
 518         unlock_super(sb);
 519 }
 520 
 521 void sysv_put_super(struct super_block *sb)
     /*  */
 522 {
 523         /* we can assume sysv_write_super() has already been called */
 524         lock_super(sb);
 525         brelse(sb->sv_bh1);
 526         if (sb->sv_bh1 != sb->sv_bh2) brelse(sb->sv_bh2);
 527         /* switch back to default block size */
 528         if (sb->s_blocksize != BLOCK_SIZE)
 529                 set_blocksize(sb->s_dev,BLOCK_SIZE);
 530         sb->s_dev = 0;
 531         unlock_super(sb);
 532         MOD_DEC_USE_COUNT;
 533 }
 534 
 535 void sysv_statfs(struct super_block *sb, struct statfs *buf, int bufsiz)
     /*  */
 536 {
 537         struct statfs tmp;
 538 
 539         tmp.f_type = sb->s_magic;
 540         tmp.f_bsize = sb->sv_block_size;
 541         tmp.f_blocks = sb->sv_ndatazones;
 542         tmp.f_bfree = sysv_count_free_blocks(sb);
 543         tmp.f_bavail = tmp.f_bfree;
 544         tmp.f_files = sb->sv_ninodes;
 545         tmp.f_ffree = sysv_count_free_inodes(sb);
 546         tmp.f_namelen = SYSV_NAMELEN;
 547         memcpy_tofs(buf, &tmp, bufsiz);
 548 }
 549 
 550 
 551 /* bmap support for running executables and shared libraries. */
 552 
 553 static inline int inode_bmap(struct super_block * sb, struct inode * inode, int nr)
     /*  */
 554 {
 555         int tmp = inode->u.sysv_i.i_data[nr];
 556         if (!tmp)
 557                 return 0;
 558         return tmp + sb->sv_block_base;
 559 }
 560 
 561 static int block_bmap(struct super_block * sb, struct buffer_head * bh, int nr, int convert)
     /*  */
 562 {
 563         int tmp;
 564 
 565         if (!bh)
 566                 return 0;
 567         tmp = ((sysv_zone_t *) bh->b_data) [nr];
 568         if (convert)
 569                 tmp = from_coh_ulong(tmp);
 570         brelse(bh);
 571         if (!tmp)
 572                 return 0;
 573         return tmp + sb->sv_block_base;
 574 }
 575 
 576 int sysv_bmap(struct inode * inode,int block_nr)
     /*  */
 577 {
 578         unsigned int block = block_nr;
 579         struct super_block * sb = inode->i_sb;
 580         int convert;
 581         int i;
 582         struct buffer_head * bh;
 583 
 584         if (block < 10)
 585                 return inode_bmap(sb,inode,block);
 586         block -= 10;
 587         convert = sb->sv_convert;
 588         if (block < sb->sv_ind_per_block) {
 589                 i = inode_bmap(sb,inode,10);
 590                 if (!i)
 591                         return 0;
 592                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 593                 return block_bmap(sb, bh, block, convert);
 594         }
 595         block -= sb->sv_ind_per_block;
 596         if (block < sb->sv_ind_per_block_2) {
 597                 i = inode_bmap(sb,inode,11);
 598                 if (!i)
 599                         return 0;
 600                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 601                 i = block_bmap(sb, bh, block >> sb->sv_ind_per_block_bits, convert);
 602                 if (!i)
 603                         return 0;
 604                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 605                 return block_bmap(sb, bh, block & sb->sv_ind_per_block_1, convert);
 606         }
 607         block -= sb->sv_ind_per_block_2;
 608         if (block < sb->sv_ind_per_block_3) {
 609                 i = inode_bmap(sb,inode,12);
 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_2_bits, convert);
 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_bits) & sb->sv_ind_per_block_1,convert);
 618                 if (!i)
 619                         return 0;
 620                 bh = bread(inode->i_dev,i,sb->sv_block_size);
 621                 return block_bmap(sb, bh, block & sb->sv_ind_per_block_1, convert);
 622         }
 623         if ((int)block<0) {
 624                 printk("sysv_bmap: block<0");
 625                 return 0;
 626         }
 627         printk("sysv_bmap: block>big");
 628         return 0;
 629 }
 630 
 631 /* End of bmap support. */
 632 
 633 
 634 /* Access selected blocks of regular files (or directories) */
 635 
 636 static struct buffer_head * inode_getblk(struct inode * inode, int nr, int create)
     /*  */
 637 {
 638         struct super_block *sb;
 639         unsigned long tmp;
 640         unsigned long *p;
 641         struct buffer_head * result;
 642 
 643         sb = inode->i_sb;
 644         p = inode->u.sysv_i.i_data + nr;
 645 repeat:
 646         tmp = *p;
 647         if (tmp) {
 648                 result = sv_getblk(sb, inode->i_dev, tmp);
 649                 if (tmp == *p)
 650                         return result;
 651                 brelse(result);
 652                 goto repeat;
 653         }
 654         if (!create)
 655                 return NULL;
 656         tmp = sysv_new_block(sb);
 657         if (!tmp)
 658                 return NULL;
 659         result = sv_getblk(sb, inode->i_dev, tmp);
 660         if (*p) {
 661                 sysv_free_block(sb,tmp);
 662                 brelse(result);
 663                 goto repeat;
 664         }
 665         *p = tmp;
 666         inode->i_ctime = CURRENT_TIME;
 667         inode->i_dirt = 1;
 668         return result;
 669 }
 670 
 671 static struct buffer_head * block_getblk(struct inode * inode, 
     /*  */
 672         struct buffer_head * bh, int nr, int create)
 673 {
 674         struct super_block *sb;
 675         unsigned long tmp, block;
 676         sysv_zone_t *p;
 677         struct buffer_head * result;
 678 
 679         if (!bh)
 680                 return NULL;
 681         if (!bh->b_uptodate) {
 682                 ll_rw_block(READ, 1, &bh);
 683                 wait_on_buffer(bh);
 684                 if (!bh->b_uptodate) {
 685                         brelse(bh);
 686                         return NULL;
 687                 }
 688         }
 689         sb = inode->i_sb;
 690         p = nr + (sysv_zone_t *) bh->b_data;
 691 repeat:
 692         block = tmp = *p;
 693         if (sb->sv_convert)
 694                 block = from_coh_ulong(block);
 695         if (tmp) {
 696                 result = sv_getblk(sb, bh->b_dev, block);
 697                 if (tmp == *p) {
 698                         brelse(bh);
 699                         return result;
 700                 }
 701                 brelse(result);
 702                 goto repeat;
 703         }
 704         if (!create) {
 705                 brelse(bh);
 706                 return NULL;
 707         }
 708         block = sysv_new_block(sb);
 709         if (!block) {
 710                 brelse(bh);
 711                 return NULL;
 712         }
 713         result = sv_getblk(sb, bh->b_dev, block);
 714         if (*p) {
 715                 sysv_free_block(sb,block);
 716                 brelse(result);
 717                 goto repeat;
 718         }
 719         *p = (sb->sv_convert ? to_coh_ulong(block) : block);
 720         mark_buffer_dirty(bh, 1);
 721         brelse(bh);
 722         return result;
 723 }
 724 
 725 struct buffer_head * sysv_getblk(struct inode * inode, unsigned int block, int create)
     /*  */
 726 {
 727         struct super_block * sb = inode->i_sb;
 728         struct buffer_head * bh;
 729 
 730         if (block < 10)
 731                 return inode_getblk(inode,block,create);
 732         block -= 10;
 733         if (block < sb->sv_ind_per_block) {
 734                 bh = inode_getblk(inode,10,create);
 735                 return block_getblk(inode, bh, block, create);
 736         }
 737         block -= sb->sv_ind_per_block;
 738         if (block < sb->sv_ind_per_block_2) {
 739                 bh = inode_getblk(inode,11,create);
 740                 bh = block_getblk(inode, bh, block >> sb->sv_ind_per_block_bits, create);
 741                 return block_getblk(inode, bh, block & sb->sv_ind_per_block_1, create);
 742         }
 743         block -= sb->sv_ind_per_block_2;
 744         if (block < sb->sv_ind_per_block_3) {
 745                 bh = inode_getblk(inode,12,create);
 746                 bh = block_getblk(inode, bh, block >> sb->sv_ind_per_block_2_bits, create);
 747                 bh = block_getblk(inode, bh, (block >> sb->sv_ind_per_block_bits) & sb->sv_ind_per_block_1, create);
 748                 return block_getblk(inode, bh, block & sb->sv_ind_per_block_1, create);
 749         }
 750         if ((int)block<0) {
 751                 printk("sysv_getblk: block<0");
 752                 return NULL;
 753         }
 754         printk("sysv_getblk: block>big");
 755         return NULL;
 756 }
 757 
 758 struct buffer_head * sysv_file_bread(struct inode * inode, int block, int create)
     /*  */
 759 {
 760         struct buffer_head * bh;
 761 
 762         bh = sysv_getblk(inode,block,create);
 763         if (!bh || bh->b_uptodate)
 764                 return bh;
 765         ll_rw_block(READ, 1, &bh);
 766         wait_on_buffer(bh);
 767         if (bh->b_uptodate)
 768                 return bh;
 769         brelse(bh);
 770         return NULL;
 771 }
 772 
 773 
 774 static inline unsigned long read3byte (char * p)
     /*  */
 775 {
 776         return (unsigned long)(*(unsigned short *)p)
 777              | (unsigned long)(*(unsigned char *)(p+2)) << 16;
 778 }
 779 
 780 static inline void write3byte (char * p, unsigned long val)
     /*  */
 781 {
 782         *(unsigned short *)p = (unsigned short) val;
 783         *(unsigned char *)(p+2) = val >> 16;
 784 }
 785 
 786 static inline unsigned long coh_read3byte (char * p)
     /*  */
 787 {
 788         return (unsigned long)(*(unsigned char *)p) << 16
 789              | (unsigned long)(*(unsigned short *)(p+1));
 790 }
 791 
 792 static inline void coh_write3byte (char * p, unsigned long val)
     /*  */
 793 {
 794         *(unsigned char *)p = val >> 16;
 795         *(unsigned short *)(p+1) = (unsigned short) val;
 796 }
 797 
 798 void sysv_read_inode(struct inode * inode)
     /*  */
 799 {
 800         struct super_block * sb = inode->i_sb;
 801         struct buffer_head * bh;
 802         struct sysv_inode * raw_inode;
 803         unsigned int block, ino;
 804         umode_t mode;
 805 
 806         ino = inode->i_ino;
 807         inode->i_op = NULL;
 808         inode->i_mode = 0;
 809         if (!ino || ino > sb->sv_ninodes) {
 810                 printk("Bad inode number on dev %s"
 811                        ": %d is out of range\n",
 812                        kdevname(inode->i_dev), ino);
 813                 return;
 814         }
 815         block = sb->sv_firstinodezone + ((ino-1) >> sb->sv_inodes_per_block_bits);
 816         if (!(bh = sv_bread(sb,inode->i_dev,block))) {
 817                 printk("Major problem: unable to read inode from dev "
 818                        "%s\n",
 819                        kdevname(inode->i_dev));
 820                 return;
 821         }
 822         raw_inode = (struct sysv_inode *) bh->b_data + ((ino-1) & sb->sv_inodes_per_block_1);
 823         mode = raw_inode->i_mode;
 824         if (sb->sv_kludge_symlinks)
 825                 mode = from_coh_imode(mode);
 826         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 827         inode->i_mode = mode;
 828         inode->i_uid = raw_inode->i_uid;
 829         inode->i_gid = raw_inode->i_gid;
 830         inode->i_nlink = raw_inode->i_nlink;
 831         if (sb->sv_convert) {
 832                 inode->i_size = from_coh_ulong(raw_inode->i_size);
 833                 inode->i_atime = from_coh_ulong(raw_inode->i_atime);
 834                 inode->i_mtime = from_coh_ulong(raw_inode->i_mtime);
 835                 inode->i_ctime = from_coh_ulong(raw_inode->i_ctime);
 836         } else {
 837                 inode->i_size = raw_inode->i_size;
 838                 inode->i_atime = raw_inode->i_atime;
 839                 inode->i_mtime = raw_inode->i_mtime;
 840                 inode->i_ctime = raw_inode->i_ctime;
 841         }
 842         inode->i_blocks = inode->i_blksize = 0;
 843         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 844                 inode->i_rdev = to_kdev_t(raw_inode->i_a.i_rdev);
 845         else
 846         if (sb->sv_convert)
 847                 for (block = 0; block < 10+1+1+1; block++)
 848                         inode->u.sysv_i.i_data[block] =
 849                                 coh_read3byte(&raw_inode->i_a.i_addb[3*block]);
 850         else
 851                 for (block = 0; block < 10+1+1+1; block++)
 852                         inode->u.sysv_i.i_data[block] =
 853                                 read3byte(&raw_inode->i_a.i_addb[3*block]);
 854         brelse(bh);
 855         if (S_ISREG(inode->i_mode))
 856                 inode->i_op = &sysv_file_inode_operations;
 857         else if (S_ISDIR(inode->i_mode))
 858                 inode->i_op = &sysv_dir_inode_operations;
 859         else if (S_ISLNK(inode->i_mode))
 860                 inode->i_op = &sysv_symlink_inode_operations;
 861         else if (S_ISCHR(inode->i_mode))
 862                 inode->i_op = &chrdev_inode_operations;
 863         else if (S_ISBLK(inode->i_mode))
 864                 inode->i_op = &blkdev_inode_operations;
 865         else if (S_ISFIFO(inode->i_mode))
 866                 init_fifo(inode);
 867 }
 868 
 869 /* To avoid inconsistencies between inodes in memory and inodes on disk. */
 870 extern int sysv_notify_change(struct inode *inode, struct iattr *attr)
     /*  */
 871 {
 872         int error;
 873 
 874         if ((error = inode_change_ok(inode, attr)) != 0)
 875                 return error;
 876 
 877         if (attr->ia_valid & ATTR_MODE)
 878                 if (inode->i_sb->sv_kludge_symlinks)
 879                         if (attr->ia_mode == COH_KLUDGE_SYMLINK_MODE)
 880                                 attr->ia_mode = COH_KLUDGE_NOT_SYMLINK;
 881 
 882         inode_setattr(inode, attr);
 883 
 884         return 0;
 885 }
 886 
 887 static struct buffer_head * sysv_update_inode(struct inode * inode)
     /*  */
 888 {
 889         struct super_block * sb = inode->i_sb;
 890         struct buffer_head * bh;
 891         struct sysv_inode * raw_inode;
 892         unsigned int ino, block;
 893         umode_t mode;
 894 
 895         ino = inode->i_ino;
 896         if (!ino || ino > sb->sv_ninodes) {
 897                 printk("Bad inode number on dev %s"
 898                        ": %d is out of range\n",
 899                        kdevname(inode->i_dev), ino);
 900                 inode->i_dirt = 0;
 901                 return 0;
 902         }
 903         block = sb->sv_firstinodezone + ((ino-1) >> sb->sv_inodes_per_block_bits);
 904         if (!(bh = sv_bread(sb,inode->i_dev,block))) {
 905                 printk("unable to read i-node block\n");
 906                 inode->i_dirt = 0;
 907                 return 0;
 908         }
 909         raw_inode = (struct sysv_inode *) bh->b_data + ((ino-1) & sb->sv_inodes_per_block_1);
 910         mode = inode->i_mode;
 911         if (sb->sv_kludge_symlinks)
 912                 mode = to_coh_imode(mode);
 913         raw_inode->i_mode = mode;
 914         raw_inode->i_uid = inode->i_uid;
 915         raw_inode->i_gid = inode->i_gid;
 916         raw_inode->i_nlink = inode->i_nlink;
 917         if (sb->sv_convert) {
 918                 raw_inode->i_size = to_coh_ulong(inode->i_size);
 919                 raw_inode->i_atime = to_coh_ulong(inode->i_atime);
 920                 raw_inode->i_mtime = to_coh_ulong(inode->i_mtime);
 921                 raw_inode->i_ctime = to_coh_ulong(inode->i_ctime);
 922         } else {
 923                 raw_inode->i_size = inode->i_size;
 924                 raw_inode->i_atime = inode->i_atime;
 925                 raw_inode->i_mtime = inode->i_mtime;
 926                 raw_inode->i_ctime = inode->i_ctime;
 927         }
 928         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 929                 raw_inode->i_a.i_rdev = kdev_t_to_nr(inode->i_rdev); /* write 2 or 3 bytes ?? */
 930         else
 931         if (sb->sv_convert)
 932                 for (block = 0; block < 10+1+1+1; block++)
 933                         coh_write3byte(&raw_inode->i_a.i_addb[3*block],inode->u.sysv_i.i_data[block]);
 934         else
 935                 for (block = 0; block < 10+1+1+1; block++)
 936                         write3byte(&raw_inode->i_a.i_addb[3*block],inode->u.sysv_i.i_data[block]);
 937         inode->i_dirt=0;
 938         mark_buffer_dirty(bh, 1);
 939         return bh;
 940 }
 941 
 942 void sysv_write_inode(struct inode * inode)
     /*  */
 943 {
 944         struct buffer_head *bh;
 945         bh = sysv_update_inode(inode);
 946         brelse(bh);
 947 }
 948 
 949 int sysv_sync_inode(struct inode * inode)
     /*  */
 950 {
 951         int err = 0;
 952         struct buffer_head *bh;
 953 
 954         bh = sysv_update_inode(inode);
 955         if (bh && bh->b_dirt) {
 956                 ll_rw_block(WRITE, 1, &bh);
 957                 wait_on_buffer(bh);
 958                 if (bh->b_req && !bh->b_uptodate)
 959                 {
 960                         printk ("IO error syncing sysv inode ["
 961                                 "%s:%08lx]\n",
 962                                 kdevname(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 static struct file_system_type sysv_fs_type[3] = {
 977         {sysv_read_super, "xenix", 1, NULL},
 978         {sysv_read_super, "sysv", 1, NULL},
 979         {sysv_read_super, "coherent", 1, NULL}
 980 };
 981 
 982 int init_module(void)
     /*  */
 983 {
 984         int i;
 985         int ouch;
 986 
 987         for (i = 0; i < 3; i++) {
 988                 if ((ouch = register_filesystem(&sysv_fs_type[i])) != 0)
 989                         return ouch;
 990         }
 991         return 0;
 992 }
 993 
 994 void cleanup_module(void)
     /*  */
 995 {
 996         int i;
 997 
 998         for (i = 0; i < 3; i++)
 999                 /* No error message if this breaks... that's OK... */
1000                 unregister_filesystem(&sysv_fs_type[i]);
1001 }
1002 
1003 #endif
/* */
root/fs/sysv/inode.c

DEFINITIONS
