fs/sysv/inode.c

/* */
This source file includes following definitions.
_coh_wait_on_inode
sysv_put_inode
detected_bs512
detected_bs1024
detect_xenix
detect_sysv4
detect_sysv2
detect_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
   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 void _coh_wait_on_inode (struct inode * inode)
     /*  */
  34 {
  35         struct wait_queue wait = { current, NULL };
  36 
  37         add_wait_queue(&inode->u.sysv_i.i_wait, &wait);
  38 repeat:
  39         current->state = TASK_UNINTERRUPTIBLE;
  40         if (inode->u.sysv_i.i_lock) {
  41                 schedule();
  42                 goto repeat;
  43         }
  44         remove_wait_queue(&inode->u.sysv_i.i_wait, &wait);
  45         current->state = TASK_RUNNING;
  46 }
  47 
  48 void sysv_put_inode(struct inode *inode)
     /*  */
  49 {
  50         if (inode->i_nlink)
  51                 return;
  52         inode->i_size = 0;
  53         sysv_truncate(inode);
  54         sysv_free_inode(inode);
  55 }
  56 
  57 
  58 static struct super_operations sysv_sops = { 
  59         sysv_read_inode,
  60         sysv_notify_change,
  61         sysv_write_inode,
  62         sysv_put_inode,
  63         sysv_put_super,
  64         sysv_write_super,
  65         sysv_statfs,
  66         NULL
  67 };
  68 
  69 /* The following functions try to recognize specific filesystems.
  70  * We recognize:
  71  * - Xenix FS by its magic number.
  72  * - SystemV FS by its magic number.
  73  * - Coherent FS by its funny fname/fpack field.
  74  * We discriminate among SystemV4 and SystemV2 FS by the assumption that
  75  * the time stamp is not < 01-01-1980.
  76  */
  77 
  78 static void detected_bs512 (struct super_block *sb)
     /*  */
  79 {
  80         sb->sv_block_size = 512;
  81         sb->sv_block_size_1 = 512-1;
  82         sb->sv_block_size_bits = 9;
  83         sb->sv_block_size_ratio = 2;
  84         sb->sv_block_size_ratio_1 = 2-1;
  85         sb->sv_block_size_ratio_bits = 1;
  86         sb->sv_inodes_per_block = 512/64;
  87         sb->sv_inodes_per_block_1 = 512/64-1;
  88         sb->sv_inodes_per_block_bits = 9-6;
  89         sb->sv_toobig_block = 10 + 
  90           (sb->sv_ind_per_block = 512/4) +
  91           (sb->sv_ind_per_block_2 = (512/4)*(512/4)) +
  92           (sb->sv_ind_per_block_3 = (512/4)*(512/4)*(512/4));
  93         sb->sv_ind_per_block_1 = 512/4-1;
  94         sb->sv_ind_per_block_2_1 = (512/4)*(512/4)-1;
  95         sb->sv_ind_per_block_2_bits = 2 *
  96           (sb->sv_ind_per_block_bits = 9-2);
  97 }
  98 
  99 static void detected_bs1024 (struct super_block *sb)
     /*  */
 100 {
 101         sb->sv_block_size = 1024;
 102         sb->sv_block_size_1 = 1024-1;
 103         sb->sv_block_size_bits = 10;
 104         sb->sv_block_size_ratio = 1;
 105         sb->sv_block_size_ratio_1 = 1-1;
 106         sb->sv_block_size_ratio_bits = 0;
 107         sb->sv_inodes_per_block = 1024/64;
 108         sb->sv_inodes_per_block_1 = 1024/64-1;
 109         sb->sv_inodes_per_block_bits = 10-6;
 110         sb->sv_toobig_block = 10 + 
 111           (sb->sv_ind_per_block = 1024/4) +
 112           (sb->sv_ind_per_block_2 = (1024/4)*(1024/4)) +
 113           (sb->sv_ind_per_block_3 = (1024/4)*(1024/4)*(1024/4));
 114         sb->sv_ind_per_block_1 = 1024/4-1;
 115         sb->sv_ind_per_block_2_1 = (1024/4)*(1024/4)-1;
 116         sb->sv_ind_per_block_2_bits = 2 *
 117           (sb->sv_ind_per_block_bits = 10-2);
 118 }
 119 
 120 static const char* detect_xenix (struct super_block *sb, struct buffer_head *bh)
     /*  */
 121 {
 122         struct xenix_super_block * sbd;
 123 
 124         sbd = (struct xenix_super_block *) bh->b_data;
 125         if (sbd->s_magic != 0x2b5544)
 126                 return NULL;
 127         sb->sv_type = FSTYPE_XENIX;
 128         sb->sv_convert = 0;
 129         sb->sv_kludge_symlinks = 1;
 130         sb->sv_truncate = 1;
 131         sb->sv_link_max = XENIX_LINK_MAX;
 132         sb->sv_fic_size = XENIX_NICINOD;
 133         sb->sv_flc_size = XENIX_NICFREE;
 134         sb->sv_bh = bh;
 135         sb->sv_sbd = (char *) sbd;
 136         sb->sv_sb_fic_count = &sbd->s_ninode;
 137         sb->sv_sb_fic_inodes = &sbd->s_inode[0];
 138         sb->sv_sb_total_free_inodes = &sbd->s_tinode;
 139         sb->sv_sb_flc_count = &sbd->s_nfree;
 140         sb->sv_sb_flc_blocks = &sbd->s_free[0];
 141         sb->sv_sb_total_free_blocks = &sbd->s_tfree;
 142         sb->sv_sb_time = &sbd->s_time;
 143         sb->sv_block_base = 0;
 144         sb->sv_firstinodezone = 2;
 145         sb->sv_firstdatazone = sbd->s_isize;
 146         sb->sv_nzones = sbd->s_fsize;
 147         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 148         switch (sbd->s_type) {
 149                 case 1: detected_bs512(sb); break;
 150                 case 2: detected_bs1024(sb); break;
 151                 default: return NULL;
 152         }
 153         return "Xenix";
 154 }
 155 
 156 static const char* detect_sysv4 (struct super_block *sb, struct buffer_head *bh)
     /*  */
 157 {
 158         struct sysv4_super_block * sbd;
 159 
 160         sbd = (struct sysv4_super_block *) (bh->b_data + BLOCK_SIZE/2);
 161         if (sbd->s_magic != 0xfd187e20)
 162                 return NULL;
 163         if (sbd->s_time < 315532800) /* this is likely to happen on SystemV2 FS */
 164                 return NULL;
 165         sb->sv_type = FSTYPE_SYSV4;
 166         sb->sv_convert = 0;
 167         sb->sv_kludge_symlinks = 0; /* ?? */
 168         sb->sv_truncate = 1;
 169         sb->sv_link_max = SYSV_LINK_MAX;
 170         sb->sv_fic_size = SYSV_NICINOD;
 171         sb->sv_flc_size = SYSV_NICFREE;
 172         sb->sv_bh = bh;
 173         sb->sv_sbd = (char *) sbd;
 174         sb->sv_sb_fic_count = &sbd->s_ninode;
 175         sb->sv_sb_fic_inodes = &sbd->s_inode[0];
 176         sb->sv_sb_total_free_inodes = &sbd->s_tinode;
 177         sb->sv_sb_flc_count = &sbd->s_nfree;
 178         sb->sv_sb_flc_blocks = &sbd->s_free[0];
 179         sb->sv_sb_total_free_blocks = &sbd->s_tfree;
 180         sb->sv_sb_time = &sbd->s_time;
 181         sb->sv_block_base = 0;
 182         sb->sv_firstinodezone = 2;
 183         sb->sv_firstdatazone = sbd->s_isize;
 184         sb->sv_nzones = sbd->s_fsize;
 185         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 186         switch (sbd->s_type) {
 187                 case 1: detected_bs512(sb); break;
 188                 case 2: detected_bs1024(sb); break;
 189                 default: return NULL;
 190         }
 191         return "SystemV";
 192 }
 193 
 194 static const char* detect_sysv2 (struct super_block *sb, struct buffer_head *bh)
     /*  */
 195 {
 196         struct sysv2_super_block * sbd;
 197 
 198         sbd = (struct sysv2_super_block *) (bh->b_data + BLOCK_SIZE/2);
 199         if (sbd->s_magic != 0xfd187e20)
 200                 return NULL;
 201         if (sbd->s_time < 315532800) /* this is likely to happen on SystemV4 FS */
 202                 return NULL;
 203         sb->sv_type = FSTYPE_SYSV2;
 204         sb->sv_convert = 0;
 205         sb->sv_kludge_symlinks = 0; /* ?? */
 206         sb->sv_truncate = 1;
 207         sb->sv_link_max = SYSV_LINK_MAX;
 208         sb->sv_fic_size = SYSV_NICINOD;
 209         sb->sv_flc_size = SYSV_NICFREE;
 210         sb->sv_bh = bh;
 211         sb->sv_sbd = (char *) sbd;
 212         sb->sv_sb_fic_count = &sbd->s_ninode;
 213         sb->sv_sb_fic_inodes = &sbd->s_inode[0];
 214         sb->sv_sb_total_free_inodes = &sbd->s_tinode;
 215         sb->sv_sb_flc_count = &sbd->s_nfree;
 216         sb->sv_sb_flc_blocks = &sbd->s_free[0];
 217         sb->sv_sb_total_free_blocks = &sbd->s_tfree;
 218         sb->sv_sb_time = &sbd->s_time;
 219         sb->sv_block_base = 0;
 220         sb->sv_firstinodezone = 2;
 221         sb->sv_firstdatazone = sbd->s_isize;
 222         sb->sv_nzones = sbd->s_fsize;
 223         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 224         switch (sbd->s_type) {
 225                 case 1: detected_bs512(sb); break;
 226                 case 2: detected_bs1024(sb); break;
 227                 default: return NULL;
 228         }
 229         return "SystemV Release 2";
 230 }
 231 
 232 static const char* detect_coherent (struct super_block *sb, struct buffer_head *bh)
     /*  */
 233 {
 234         struct coh_super_block * sbd;
 235 
 236         sbd = (struct coh_super_block *) (bh->b_data + BLOCK_SIZE/2);
 237         if ((memcmp(sbd->s_fname,"noname",6) && memcmp(sbd->s_fname,"xxxxx ",6))
 238             || (memcmp(sbd->s_fpack,"nopack",6) && memcmp(sbd->s_fpack,"xxxxx\n",6)))
 239                 return NULL;
 240         sb->sv_type = FSTYPE_COH;
 241         sb->sv_convert = 1;
 242         sb->sv_kludge_symlinks = 1;
 243         sb->sv_truncate = 1;
 244         sb->sv_link_max = COH_LINK_MAX;
 245         sb->sv_fic_size = COH_NICINOD;
 246         sb->sv_flc_size = COH_NICFREE;
 247         sb->sv_bh = bh;
 248         sb->sv_sbd = (char *) sbd;
 249         sb->sv_sb_fic_count = &sbd->s_ninode;
 250         sb->sv_sb_fic_inodes = &sbd->s_inode[0];
 251         sb->sv_sb_total_free_inodes = &sbd->s_tinode;
 252         sb->sv_sb_flc_count = &sbd->s_nfree;
 253         sb->sv_sb_flc_blocks = &sbd->s_free[0];
 254         sb->sv_sb_total_free_blocks = &sbd->s_tfree;
 255         sb->sv_sb_time = &sbd->s_time;
 256         sb->sv_block_base = 0;
 257         sb->sv_firstinodezone = 2;
 258         sb->sv_firstdatazone = sbd->s_isize;
 259         sb->sv_nzones = from_coh_ulong(sbd->s_fsize);
 260         sb->sv_ndatazones = sb->sv_nzones - sb->sv_firstdatazone;
 261         detected_bs512(sb);
 262         return "Coherent";
 263 }
 264 
 265 struct super_block *sysv_read_super(struct super_block *sb,void *data, 
     /*  */
 266                                      int silent)
 267 {
 268         struct buffer_head *bh;
 269         const char *found;
 270         int dev = sb->s_dev;
 271 
 272         if (1024 != sizeof (struct xenix_super_block))
 273                 panic("Xenix FS: bad super-block size");
 274         if ((512 != sizeof (struct sysv4_super_block))
 275             || (512 != sizeof (struct sysv2_super_block)))
 276                 panic("SystemV FS: bad super-block size");
 277         if (500 != sizeof (struct coh_super_block))
 278                 panic("Coherent FS: bad super-block size");
 279         if (64 != sizeof (struct sysv_inode))
 280                 panic("sysv fs: bad i-node size");
 281         lock_super(sb);
 282         sb->s_blocksize = BLOCK_SIZE; /* anything else not supported by the block device drivers */
 283         sb->s_blocksize_bits = BLOCK_SIZE_BITS;
 284 
 285         /* Try to read Xenix superblock */
 286         if ((bh = bread(dev, 1, BLOCK_SIZE)) != NULL) {
 287                 if ((found = detect_xenix(sb,bh)) != NULL)
 288                         goto ok;
 289                 brelse(bh);
 290         }
 291         if ((bh = bread(dev, 0, BLOCK_SIZE)) != NULL) {
 292                 /* Try to recognize SystemV superblock */
 293                 if ((found = detect_sysv4(sb,bh)) != NULL)
 294                         goto ok;
 295                 if ((found = detect_sysv2(sb,bh)) != NULL)
 296                         goto ok;
 297                 /* Try to recognize Coherent superblock */
 298                 if ((found = detect_coherent(sb,bh)) != NULL)
 299                         goto ok;
 300                 brelse(bh);
 301         }
 302         /* Try to recognize SystemV2 superblock */
 303         /* Offset by 1 track, i.e. most probably 9, 15, or 18 kilobytes. */
 304         {       static int offsets[] = { 9, 15, 18, };
 305                 int i;
 306                 for (i = 0; i < sizeof(offsets)/sizeof(offsets[0]); i++)
 307                         if ((bh = bread(dev, offsets[i], BLOCK_SIZE)) != NULL) {
 308                                 /* Try to recognize SystemV superblock */
 309                                 if ((found = detect_sysv2(sb,bh)) != NULL) {
 310                                         sb->sv_block_base = offsets[i];
 311                                         goto ok;
 312                                 }
 313                                 brelse(bh);
 314                         }
 315         }
 316         sb->s_dev=0;
 317         unlock_super(sb);
 318         if (!silent)
 319                 printk("VFS: unable to read Xenix/SystemV/Coherent superblock\n");
 320         return NULL;
 321 
 322         ok:
 323         sb->sv_ninodes = (sb->sv_firstdatazone - sb->sv_firstinodezone) << sb->sv_inodes_per_block_bits;
 324         if (!silent)
 325                 printk("VFS: Found a %s FS (block size = %d) on device %d/%d\n",found,sb->sv_block_size,MAJOR(dev),MINOR(dev));
 326         sb->s_magic = SYSV_MAGIC_BASE + sb->sv_type;
 327         /* set up enough so that it can read an inode */
 328         sb->s_dev = dev;
 329         sb->s_op = &sysv_sops;
 330         sb->s_mounted = iget(sb,SYSV_ROOT_INO);
 331         unlock_super(sb);
 332         if (!sb->s_mounted) {
 333                 brelse(bh);
 334                 sb->s_dev = 0;
 335                 printk("SysV FS: get root inode failed\n");
 336                 return NULL;
 337         }
 338         sb->s_dirt = 1; /* brelse(bh); occurs when the disk is unmounted. */
 339         return sb;
 340 }
 341 
 342 /* This is only called on sync() and umount(), when s_dirt=1. */
 343 void sysv_write_super (struct super_block *sb)
     /*  */
 344 {
 345         lock_super(sb);
 346         if (sb->sv_bh->b_dirt) {
 347                 /* If we are going to write out the super block,
 348                    then attach current time stamp. */
 349                 unsigned long time = CURRENT_TIME;
 350                 if (sb->sv_convert)
 351                         time = to_coh_ulong(time);
 352                 *sb->sv_sb_time = time;
 353         }
 354         sb->s_dirt = 0;
 355         unlock_super(sb);
 356 }
 357 
 358 void sysv_put_super(struct super_block *sb)
     /*  */
 359 {
 360         /* we can assume sysv_write_super() has already been called */
 361         lock_super(sb);
 362         brelse(sb->sv_bh);
 363         sb->s_dev = 0;
 364         unlock_super(sb);
 365 }
 366 
 367 void sysv_statfs(struct super_block *sb, struct statfs *buf)
     /*  */
 368 {
 369         long tmp;
 370 
 371         put_fs_long(sb->s_magic, &buf->f_type);         /* type of filesystem */
 372         put_fs_long(sb->sv_block_size, &buf->f_bsize);  /* block size */
 373         put_fs_long(sb->sv_ndatazones, &buf->f_blocks); /* total data blocks in file system */
 374         tmp = sysv_count_free_blocks(sb);
 375         put_fs_long(tmp, &buf->f_bfree);                /* free blocks in fs */
 376         put_fs_long(tmp, &buf->f_bavail);               /* free blocks available to non-superuser */
 377         put_fs_long(sb->sv_ninodes, &buf->f_files);     /* total file nodes in file system */
 378         put_fs_long(sysv_count_free_inodes(sb), &buf->f_ffree); /* free file nodes in fs */
 379         put_fs_long(SYSV_NAMELEN, &buf->f_namelen);
 380         /* Don't know what value to put in buf->f_fsid */       /* file system id */
 381 }
 382 
 383 
 384 /* bmap support for running executables and shared libraries.
 385    Used only if block_size = BLOCK_SIZE. */
 386 
 387 #define IND_PER_BLOCK   (BLOCK_SIZE / sizeof(sysv_zone_t))
 388 
 389 static inline int inode_bmap(struct super_block * sb, struct inode * inode, int nr)
     /*  */
 390 {
 391         int tmp = inode->u.sysv_i.i_data[nr];
 392         if (!tmp)
 393                 return 0;
 394         return tmp + sb->sv_block_base;
 395 }
 396 
 397 static int block_bmap(struct super_block * sb, struct buffer_head * bh, int nr, int convert)
     /*  */
 398 {
 399         int tmp;
 400 
 401         if (!bh)
 402                 return 0;
 403         tmp = ((sysv_zone_t *) bh->b_data) [nr];
 404         if (convert)
 405                 tmp = from_coh_ulong(tmp);
 406         brelse(bh);
 407         if (!tmp)
 408                 return 0;
 409         return tmp + sb->sv_block_base;
 410 }
 411 
 412 int sysv_bmap(struct inode * inode,int block_nr)
     /*  */
 413 {
 414         unsigned int block = block_nr;
 415         struct super_block * sb = inode->i_sb;
 416         int convert;
 417         int i;
 418         struct buffer_head * bh;
 419 
 420         if (block < 10)
 421                 return inode_bmap(sb,inode,block);
 422         block -= 10;
 423         convert = sb->sv_convert;
 424         if (block < IND_PER_BLOCK) {
 425                 i = inode_bmap(sb,inode,10);
 426                 if (!i)
 427                         return 0;
 428                 bh = bread(inode->i_dev,i,BLOCK_SIZE);
 429                 return block_bmap(sb,bh,block,convert);
 430         }
 431         block -= IND_PER_BLOCK;
 432         if (block < IND_PER_BLOCK*IND_PER_BLOCK) {
 433                 i = inode_bmap(sb,inode,11);
 434                 if (!i)
 435                         return 0;
 436                 bh = bread(inode->i_dev,i,BLOCK_SIZE);
 437                 i = block_bmap(sb,bh,block/IND_PER_BLOCK,convert);
 438                 if (!i)
 439                         return 0;
 440                 bh = bread(inode->i_dev,i,BLOCK_SIZE);
 441                 return block_bmap(sb,bh,block%IND_PER_BLOCK,convert);
 442         }
 443         block -= IND_PER_BLOCK*IND_PER_BLOCK;
 444         if (block < IND_PER_BLOCK*IND_PER_BLOCK*IND_PER_BLOCK) {
 445                 i = inode_bmap(sb,inode,12);
 446                 if (!i)
 447                         return 0;
 448                 bh = bread(inode->i_dev,i,BLOCK_SIZE);
 449                 i = block_bmap(sb,bh,block/(IND_PER_BLOCK*IND_PER_BLOCK),convert);
 450                 if (!i)
 451                         return 0;
 452                 bh = bread(inode->i_dev,i,BLOCK_SIZE);
 453                 i = block_bmap(sb,bh,(block/IND_PER_BLOCK)%IND_PER_BLOCK,convert);
 454                 if (!i)
 455                         return 0;
 456                 bh = bread(inode->i_dev,i,BLOCK_SIZE);
 457                 return block_bmap(sb,bh,block%IND_PER_BLOCK,convert);
 458         }
 459         if ((int)block<0) {
 460                 printk("sysv_bmap: block<0");
 461                 return 0;
 462         }
 463         printk("sysv_bmap: block>big");
 464         return 0;
 465 }
 466 
 467 /* End of bmap support. */
 468 
 469 
 470 /* Access selected blocks of regular files (or directories) */
 471 
 472 static struct buffer_head * inode_getblk(struct inode * inode, int nr, int create, char * *start)
     /*  */
 473 {
 474         struct super_block *sb;
 475         unsigned long tmp;
 476         unsigned long *p;
 477         struct buffer_head * result;
 478 
 479         sb = inode->i_sb;
 480         p = inode->u.sysv_i.i_data + nr;
 481 repeat:
 482         tmp = *p;
 483         if (tmp) {
 484                 result = getblk(inode->i_dev, (tmp >> sb->sv_block_size_ratio_bits) + sb->sv_block_base, BLOCK_SIZE);
 485                 if (tmp == *p) {
 486                         *start = result->b_data + ((tmp & sb->sv_block_size_ratio_1) << sb->sv_block_size_bits);
 487                         return result;
 488                 }
 489                 brelse(result);
 490                 goto repeat;
 491         }
 492         if (!create)
 493                 return NULL;
 494         tmp = sysv_new_block(sb);
 495         if (!tmp)
 496                 return NULL;
 497         result = getblk(inode->i_dev, (tmp >> sb->sv_block_size_ratio_bits) + sb->sv_block_base, BLOCK_SIZE);
 498         if (*p) {
 499                 sysv_free_block(sb,tmp);
 500                 brelse(result);
 501                 goto repeat;
 502         }
 503         *p = tmp;
 504         inode->i_ctime = CURRENT_TIME;
 505         inode->i_dirt = 1;
 506         *start = result->b_data + ((tmp & sb->sv_block_size_ratio_1) << sb->sv_block_size_bits);
 507         return result;
 508 }
 509 
 510 static struct buffer_head * block_getblk(struct inode * inode, 
     /*  */
 511         struct buffer_head * bh, int nr, int create, char * *start)
 512 {
 513         struct super_block *sb;
 514         unsigned long tmp, block;
 515         sysv_zone_t *p;
 516         struct buffer_head * result;
 517 
 518         if (!bh)
 519                 return NULL;
 520         if (!bh->b_uptodate) {
 521                 ll_rw_block(READ, 1, &bh);
 522                 wait_on_buffer(bh);
 523                 if (!bh->b_uptodate) {
 524                         brelse(bh);
 525                         return NULL;
 526                 }
 527         }
 528         sb = inode->i_sb;
 529         p = nr + (sysv_zone_t *) *start;
 530 repeat:
 531         block = tmp = *p;
 532         if (sb->sv_convert)
 533                 block = from_coh_ulong(block);
 534         if (tmp) {
 535                 result = getblk(bh->b_dev, (block >> sb->sv_block_size_ratio_bits) + sb->sv_block_base, BLOCK_SIZE);
 536                 if (tmp == *p) {
 537                         brelse(bh);
 538                         *start = result->b_data + ((block & sb->sv_block_size_ratio_1) << sb->sv_block_size_bits);
 539                         return result;
 540                 }
 541                 brelse(result);
 542                 goto repeat;
 543         }
 544         if (!create) {
 545                 brelse(bh);
 546                 return NULL;
 547         }
 548         block = sysv_new_block(sb);
 549         if (!block) {
 550                 brelse(bh);
 551                 return NULL;
 552         }
 553         result = getblk(bh->b_dev, (block >> sb->sv_block_size_ratio_bits) + sb->sv_block_base, BLOCK_SIZE);
 554         if (*p) {
 555                 sysv_free_block(sb,block);
 556                 brelse(result);
 557                 goto repeat;
 558         }
 559         *p = (sb->sv_convert ? to_coh_ulong(block) : block);
 560         bh->b_dirt = 1;
 561         brelse(bh);
 562         *start = result->b_data + ((block & sb->sv_block_size_ratio_1) << sb->sv_block_size_bits);
 563         return result;
 564 }
 565 
 566 struct buffer_head * sysv_getblk(struct inode * inode, unsigned int block,
     /*  */
 567         int create, char * *start)
 568 {
 569         struct super_block * sb = inode->i_sb;
 570         struct buffer_head * bh;
 571 
 572         if (block < 10)
 573                 return inode_getblk(inode,block,create,start);
 574         block -= 10;
 575         if (block < sb->sv_ind_per_block) {
 576                 bh = inode_getblk(inode,10,create,start);
 577                 return block_getblk(inode, bh, block, create, start);
 578         }
 579         block -= sb->sv_ind_per_block;
 580         if (block < sb->sv_ind_per_block_2) {
 581                 bh = inode_getblk(inode,11,create,start);
 582                 bh = block_getblk(inode, bh, block >> sb->sv_ind_per_block_bits, create, start);
 583                 return block_getblk(inode, bh, block & sb->sv_ind_per_block_1, create, start);
 584         }
 585         block -= sb->sv_ind_per_block_2;
 586         if (block < sb->sv_ind_per_block_3) {
 587                 bh = inode_getblk(inode,12,create,start);
 588                 bh = block_getblk(inode, bh, block >> sb->sv_ind_per_block_2_bits, create, start);
 589                 bh = block_getblk(inode, bh, (block >> sb->sv_ind_per_block_bits) & sb->sv_ind_per_block_1, create, start);
 590                 return block_getblk(inode, bh, block & sb->sv_ind_per_block_1, create, start);
 591         }
 592         if ((int)block<0) {
 593                 printk("sysv_getblk: block<0");
 594                 return NULL;
 595         }
 596         printk("sysv_getblk: block>big");
 597         return NULL;
 598 }
 599 
 600 struct buffer_head * sysv_file_bread(struct inode * inode, int block, int create, char * *start)
     /*  */
 601 {
 602         struct buffer_head * bh;
 603 
 604         bh = sysv_getblk(inode,block,create,start);
 605         if (!bh || bh->b_uptodate)
 606                 return bh;
 607         ll_rw_block(READ, 1, &bh);
 608         wait_on_buffer(bh);
 609         if (bh->b_uptodate)
 610                 return bh;
 611         brelse(bh);
 612         return NULL;
 613 }
 614 
 615 
 616 static inline unsigned long read3byte (char * p)
     /*  */
 617 {
 618         return (unsigned long)(*(unsigned short *)p)
 619              | (unsigned long)(*(unsigned char *)(p+2)) << 16;
 620 }
 621 
 622 static inline void write3byte (char * p, unsigned long val)
     /*  */
 623 {
 624         *(unsigned short *)p = (unsigned short) val;
 625         *(unsigned char *)(p+2) = val >> 16;
 626 }
 627 
 628 static inline unsigned long coh_read3byte (char * p)
     /*  */
 629 {
 630         return (unsigned long)(*(unsigned char *)p) << 16
 631              | (unsigned long)(*(unsigned short *)(p+1));
 632 }
 633 
 634 static inline void coh_write3byte (char * p, unsigned long val)
     /*  */
 635 {
 636         *(unsigned char *)p = val >> 16;
 637         *(unsigned short *)(p+1) = (unsigned short) val;
 638 }
 639 
 640 void sysv_read_inode(struct inode * inode)
     /*  */
 641 {
 642         struct super_block * sb = inode->i_sb;
 643         struct buffer_head * bh;
 644         char * bh_data;
 645         struct sysv_inode * raw_inode;
 646         unsigned int block, ino;
 647         umode_t mode;
 648 
 649         ino = inode->i_ino;
 650         inode->i_op = NULL;
 651         inode->i_mode = 0;
 652         if (!ino || ino > sb->sv_ninodes) {
 653                 printk("Bad inode number on dev 0x%04x: %d is out of range\n",
 654                         inode->i_dev, ino);
 655                 return;
 656         }
 657         block = sb->sv_firstinodezone + ((ino-1) >> sb->sv_inodes_per_block_bits);
 658         if (!(bh=sysv_bread(sb,inode->i_dev,block,&bh_data))) {
 659                 printk("Major problem: unable to read inode from dev 0x%04x\n",
 660                         inode->i_dev);
 661                 return;
 662         }
 663         raw_inode = (struct sysv_inode *) bh_data + ((ino-1) & sb->sv_inodes_per_block_1);
 664         mode = raw_inode->i_mode;
 665         if (sb->sv_kludge_symlinks)
 666                 mode = from_coh_imode(mode);
 667         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 668         inode->i_mode = mode;
 669         inode->i_uid = raw_inode->i_uid;
 670         inode->i_gid = raw_inode->i_gid;
 671         inode->i_nlink = raw_inode->i_nlink;
 672         if (sb->sv_convert) {
 673                 inode->i_size = from_coh_ulong(raw_inode->i_size);
 674                 inode->i_atime = from_coh_ulong(raw_inode->i_atime);
 675                 inode->i_mtime = from_coh_ulong(raw_inode->i_mtime);
 676                 inode->i_ctime = from_coh_ulong(raw_inode->i_ctime);
 677         } else {
 678                 inode->i_size = raw_inode->i_size;
 679                 inode->i_atime = raw_inode->i_atime;
 680                 inode->i_mtime = raw_inode->i_mtime;
 681                 inode->i_ctime = raw_inode->i_ctime;
 682         }
 683         inode->i_blocks = inode->i_blksize = 0;
 684         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 685                 inode->i_rdev = raw_inode->i_a.i_rdev;
 686         else
 687         if (sb->sv_convert)
 688                 for (block = 0; block < 10+1+1+1; block++)
 689                         inode->u.sysv_i.i_data[block] =
 690                                 coh_read3byte(&raw_inode->i_a.i_addb[3*block]);
 691         else
 692                 for (block = 0; block < 10+1+1+1; block++)
 693                         inode->u.sysv_i.i_data[block] =
 694                                 read3byte(&raw_inode->i_a.i_addb[3*block]);
 695         brelse(bh);
 696         if (S_ISREG(inode->i_mode))
 697                 if (sb->sv_block_size_ratio_bits == 0) /* block_size == BLOCK_SIZE ? */
 698                         inode->i_op = &sysv_file_inode_operations_with_bmap;
 699                 else
 700                         inode->i_op = &sysv_file_inode_operations;
 701         else if (S_ISDIR(inode->i_mode))
 702                 inode->i_op = &sysv_dir_inode_operations;
 703         else if (S_ISLNK(inode->i_mode))
 704                 inode->i_op = &sysv_symlink_inode_operations;
 705         else if (S_ISCHR(inode->i_mode))
 706                 inode->i_op = &chrdev_inode_operations;
 707         else if (S_ISBLK(inode->i_mode))
 708                 inode->i_op = &blkdev_inode_operations;
 709         else if (S_ISFIFO(inode->i_mode))
 710                 init_fifo(inode);
 711 }
 712 
 713 /* To avoid inconsistencies between inodes in memory and inodes on disk. */
 714 extern int sysv_notify_change(int flags, struct inode *inode)
     /*  */
 715 {
 716         if (flags & NOTIFY_MODE)
 717                 if (inode->i_sb->sv_kludge_symlinks)
 718                         if (inode->i_mode == COH_KLUDGE_SYMLINK_MODE) {
 719                                 inode->i_mode = COH_KLUDGE_NOT_SYMLINK;
 720                                 inode->i_dirt = 1;
 721                         }
 722         return 0;
 723 }
 724 
 725 static struct buffer_head * sysv_update_inode(struct inode * inode)
     /*  */
 726 {
 727         struct super_block * sb = inode->i_sb;
 728         struct buffer_head * bh;
 729         char * bh_data;
 730         struct sysv_inode * raw_inode;
 731         unsigned int ino, block;
 732         umode_t mode;
 733 
 734         ino = inode->i_ino;
 735         if (!ino || ino > sb->sv_ninodes) {
 736                 printk("Bad inode number on dev 0x%04x: %d is out of range\n",
 737                         inode->i_dev, ino);
 738                 inode->i_dirt = 0;
 739                 return 0;
 740         }
 741         block = sb->sv_firstinodezone + ((ino-1) >> sb->sv_inodes_per_block_bits);
 742         if (!(bh = sysv_bread(sb,inode->i_dev,block,&bh_data))) {
 743                 printk("unable to read i-node block\n");
 744                 inode->i_dirt = 0;
 745                 return 0;
 746         }
 747         raw_inode = (struct sysv_inode *) bh_data + ((ino-1) & sb->sv_inodes_per_block_1);
 748         mode = inode->i_mode;
 749         if (sb->sv_kludge_symlinks)
 750                 mode = to_coh_imode(mode);
 751         raw_inode->i_mode = mode;
 752         raw_inode->i_uid = inode->i_uid;
 753         raw_inode->i_gid = inode->i_gid;
 754         raw_inode->i_nlink = inode->i_nlink;
 755         if (sb->sv_convert) {
 756                 raw_inode->i_size = to_coh_ulong(inode->i_size);
 757                 raw_inode->i_atime = to_coh_ulong(inode->i_atime);
 758                 raw_inode->i_mtime = to_coh_ulong(inode->i_mtime);
 759                 raw_inode->i_ctime = to_coh_ulong(inode->i_ctime);
 760         } else {
 761                 raw_inode->i_size = inode->i_size;
 762                 raw_inode->i_atime = inode->i_atime;
 763                 raw_inode->i_mtime = inode->i_mtime;
 764                 raw_inode->i_ctime = inode->i_ctime;
 765         }
 766         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 767                 raw_inode->i_a.i_rdev = inode->i_rdev; /* write 2 or 3 bytes ?? */
 768         else
 769         if (sb->sv_convert)
 770                 for (block = 0; block < 10+1+1+1; block++)
 771                         coh_write3byte(&raw_inode->i_a.i_addb[3*block],inode->u.sysv_i.i_data[block]);
 772         else
 773                 for (block = 0; block < 10+1+1+1; block++)
 774                         write3byte(&raw_inode->i_a.i_addb[3*block],inode->u.sysv_i.i_data[block]);
 775         inode->i_dirt=0;
 776         bh->b_dirt=1;
 777         return bh;
 778 }
 779 
 780 void sysv_write_inode(struct inode * inode)
     /*  */
 781 {
 782         struct buffer_head *bh;
 783         bh = sysv_update_inode(inode);
 784         brelse(bh);
 785 }
 786 
 787 int sysv_sync_inode(struct inode * inode)
     /*  */
 788 {
 789         int err = 0;
 790         struct buffer_head *bh;
 791 
 792         bh = sysv_update_inode(inode);
 793         if (bh && bh->b_dirt) {
 794                 ll_rw_block(WRITE, 1, &bh);
 795                 wait_on_buffer(bh);
 796                 if (bh->b_req && !bh->b_uptodate)
 797                 {
 798                         printk ("IO error syncing sysv inode [%04x:%08lx]\n",
 799                                 inode->i_dev, inode->i_ino);
 800                         err = -1;
 801                 }
 802         }
 803         else if (!bh)
 804                 err = -1;
 805         brelse (bh);
 806         return err;
 807 }
 808
/* */
root/fs/sysv/inode.c

DEFINITIONS
