fs/affs/super.c

   1 /*
   2  *  linux/fs/affs/inode.c
   3  *
   4  *  (c) 1996  Hans-Joachim Widmaier - Rewritten
   5  *
   6  *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
   7  *
   8  *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
   9  *
  10  *  (C) 1991  Linus Torvalds - minix filesystem
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/errno.h>
  15 #include <linux/fs.h>
  16 #include <linux/slab.h>
  17 #include <linux/stat.h>
  18 #include <linux/sched.h>
  19 #include <linux/affs_fs.h>
  20 #include <linux/kernel.h>
  21 #include <linux/mm.h>
  22 #include <linux/string.h>
  23 #include <linux/locks.h>
  24 #include <linux/genhd.h>
  25 #include <linux/amigaffs.h>
  26 #include <linux/major.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/init.h>
  29 #include <asm/system.h>
  30 #include <asm/uaccess.h>
  31
  32 extern int *blk_size[];
  33 extern struct timezone sys_tz;
  34
  35 static int affs_statfs(struct super_block *sb, struct statfs *buf);
  36 static int affs_remount (struct super_block *sb, int *flags, char *data);
  37
  38 static void
  39 affs_put_super(struct super_block *sb)
  40 {
  41         pr_debug("AFFS: put_super()\n");
  42
  43         if (!(sb->s_flags & MS_RDONLY)) {
  44                 AFFS_ROOT_TAIL(sb, AFFS_SB->s_root_bh)->bm_flag = be32_to_cpu(1);
  45                 secs_to_datestamp(CURRENT_TIME,
  46                                   &AFFS_ROOT_TAIL(sb, AFFS_SB->s_root_bh)->disk_change);
  47                 affs_fix_checksum(sb, AFFS_SB->s_root_bh);
  48                 mark_buffer_dirty(AFFS_SB->s_root_bh);
  49         }
  50
  51         if (AFFS_SB->s_prefix)
  52                 kfree(AFFS_SB->s_prefix);
  53         affs_free_bitmap(sb);
  54         affs_brelse(AFFS_SB->s_root_bh);
  55
  56         return;
  57 }
  58
  59 static void
  60 affs_write_super(struct super_block *sb)
  61 {
  62         int clean = 2;
  63
  64         if (!(sb->s_flags & MS_RDONLY)) {
  65                 //      if (AFFS_SB->s_bitmap[i].bm_bh) {
  66                 //              if (buffer_dirty(AFFS_SB->s_bitmap[i].bm_bh)) {
  67                 //                      clean = 0;
  68                 AFFS_ROOT_TAIL(sb, AFFS_SB->s_root_bh)->bm_flag = be32_to_cpu(clean);
  69                 secs_to_datestamp(CURRENT_TIME,
  70                                   &AFFS_ROOT_TAIL(sb, AFFS_SB->s_root_bh)->disk_change);
  71                 affs_fix_checksum(sb, AFFS_SB->s_root_bh);
  72                 mark_buffer_dirty(AFFS_SB->s_root_bh);
  73                 sb->s_dirt = !clean;    /* redo until bitmap synced */
  74         } else
  75                 sb->s_dirt = 0;
  76
  77         pr_debug("AFFS: write_super() at %lu, clean=%d\n", CURRENT_TIME, clean);
  78 }
  79
  80 static struct super_operations affs_sops = {
  81         read_inode:     affs_read_inode,
  82         write_inode:    affs_write_inode,
  83         put_inode:      affs_put_inode,
  84         delete_inode:   affs_delete_inode,
  85         clear_inode:    affs_clear_inode,
  86         put_super:      affs_put_super,
  87         write_super:    affs_write_super,
  88         statfs:         affs_statfs,
  89         remount_fs:     affs_remount,
  90 };
  91
  92 static int
  93 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
  94                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
  95 {
  96         char    *this_char, *value, *optn;
  97         int      f;
  98
  99         /* Fill in defaults */
 100
 101         *uid        = current->uid;
 102         *gid        = current->gid;
 103         *reserved   = 2;
 104         *root       = -1;
 105         *blocksize  = -1;
 106         volume[0]   = ':';
 107         volume[1]   = 0;
 108         *mount_opts = 0;
 109         if (!options)
 110                 return 1;
 111         for (this_char = strtok(options,","); this_char; this_char = strtok(NULL,",")) {
 112                 f = 0;
 113                 if ((value = strchr(this_char,'=')) != NULL)
 114                         *value++ = 0;
 115                 if ((optn = "protect") && !strcmp(this_char, optn)) {
 116                         if (value)
 117                                 goto out_inv_arg;
 118                         *mount_opts |= SF_IMMUTABLE;
 119                 } else if ((optn = "verbose") && !strcmp(this_char, optn)) {
 120                         if (value)
 121                                 goto out_inv_arg;
 122                         *mount_opts |= SF_VERBOSE;
 123                 } else if ((optn = "mufs") && !strcmp(this_char, optn)) {
 124                         if (value)
 125                                 goto out_inv_arg;
 126                         *mount_opts |= SF_MUFS;
 127                 } else if ((f = !strcmp(this_char,"setuid")) || !strcmp(this_char,"setgid")) {
 128                         if (value) {
 129                                 if (!*value) {
 130                                         printk("AFFS: Argument for set[ug]id option missing\n");
 131                                         return 0;
 132                                 } else {
 133                                         *(f ? uid : gid) = simple_strtoul(value,&value,0);
 134                                         if (*value) {
 135                                                 printk("AFFS: Bad set[ug]id argument\n");
 136                                                 return 0;
 137                                         }
 138                                         *mount_opts |= f ? SF_SETUID : SF_SETGID;
 139                                 }
 140                         }
 141                 } else if (!strcmp(this_char,"prefix")) {
 142                         optn = "prefix";
 143                         if (!value || !*value)
 144                                 goto out_no_arg;
 145                         if (*prefix) {          /* Free any previous prefix */
 146                                 kfree(*prefix);
 147                                 *prefix = NULL;
 148                         }
 149                         *prefix = kmalloc(strlen(value) + 1,GFP_KERNEL);
 150                         if (!*prefix)
 151                                 return 0;
 152                         strcpy(*prefix,value);
 153                         *mount_opts |= SF_PREFIX;
 154                 } else if (!strcmp(this_char,"volume")) {
 155                         optn = "volume";
 156                         if (!value || !*value)
 157                                 goto out_no_arg;
 158                         if (strlen(value) > 30)
 159                                 value[30] = 0;
 160                         strncpy(volume,value,30);
 161                 } else if (!strcmp(this_char,"mode")) {
 162                         optn = "mode";
 163                         if (!value || !*value)
 164                                 goto out_no_arg;
 165                         *mode = simple_strtoul(value,&value,8) & 0777;
 166                         if (*value)
 167                                 return 0;
 168                         *mount_opts |= SF_SETMODE;
 169                 } else if (!strcmp(this_char,"reserved")) {
 170                         optn = "reserved";
 171                         if (!value || !*value)
 172                                 goto out_no_arg;
 173                         *reserved = simple_strtoul(value,&value,0);
 174                         if (*value)
 175                                 return 0;
 176                 } else if (!strcmp(this_char,"root")) {
 177                         optn = "root";
 178                         if (!value || !*value)
 179                                 goto out_no_arg;
 180                         *root = simple_strtoul(value,&value,0);
 181                         if (*value)
 182                                 return 0;
 183                 } else if (!strcmp(this_char,"bs")) {
 184                         optn = "bs";
 185                         if (!value || !*value)
 186                                 goto out_no_arg;
 187                         *blocksize = simple_strtoul(value,&value,0);
 188                         if (*value)
 189                                 return 0;
 190                         if (*blocksize != 512 && *blocksize != 1024 && *blocksize != 2048
 191                             && *blocksize != 4096) {
 192                                 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
 193                                 return 0;
 194                         }
 195                 } else if (!strcmp (this_char, "grpquota")
 196                          || !strcmp (this_char, "noquota")
 197                          || !strcmp (this_char, "quota")
 198                          || !strcmp (this_char, "usrquota"))
 199                          /* Silently ignore the quota options */
 200                         ;
 201                 else {
 202                         printk("AFFS: Unrecognized mount option %s\n", this_char);
 203                         return 0;
 204                 }
 205         }
 206         return 1;
 207
 208 out_no_arg:
 209         printk("AFFS: The %s option requires an argument\n", optn);
 210         return 0;
 211 out_inv_arg:
 212         printk("AFFS: Option %s does not take an argument\n", optn);
 213         return 0;
 214 }
 215
 216 /* This function definitely needs to be split up. Some fine day I'll
 217  * hopefully have the guts to do so. Until then: sorry for the mess.
 218  */
 219
 220 static struct super_block *
 221 affs_read_super(struct super_block *sb, void *data, int silent)
 222 {
 223         struct buffer_head      *root_bh = NULL;
 224         struct buffer_head      *boot_bh;
 225         struct inode            *root_inode = NULL;
 226         kdev_t                   dev = sb->s_dev;
 227         s32                      root_block;
 228         int                      blocks, size, blocksize;
 229         u32                      chksum;
 230         int                      num_bm;
 231         int                      i, j;
 232         s32                      key;
 233         uid_t                    uid;
 234         gid_t                    gid;
 235         int                      reserved;
 236         unsigned long            mount_flags;
 237         int                      tmp_flags;     /* fix remount prototype... */
 238
 239         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
 240
 241         sb->s_magic             = AFFS_SUPER_MAGIC;
 242         sb->s_op                = &affs_sops;
 243         memset(AFFS_SB, 0, sizeof(*AFFS_SB));
 244         init_MUTEX(&AFFS_SB->s_bmlock);
 245
 246         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
 247                                 &blocksize,&AFFS_SB->s_prefix,
 248                                 AFFS_SB->s_volume, &mount_flags)) {
 249                 printk(KERN_ERR "AFFS: Error parsing options\n");
 250                 return NULL;
 251         }
 252         /* N.B. after this point s_prefix must be released */
 253
 254         AFFS_SB->s_flags   = mount_flags;
 255         AFFS_SB->s_mode    = i;
 256         AFFS_SB->s_uid     = uid;
 257         AFFS_SB->s_gid     = gid;
 258         AFFS_SB->s_reserved= reserved;
 259
 260         /* Get the size of the device in 512-byte blocks.
 261          * If we later see that the partition uses bigger
 262          * blocks, we will have to change it.
 263          */
 264
 265         blocks = blk_size[MAJOR(dev)] ? blk_size[MAJOR(dev)][MINOR(dev)] : 0;
 266         if (!blocks) {
 267                 printk(KERN_ERR "AFFS: Could not determine device size\n");
 268                 goto out_error;
 269         }
 270         size = (BLOCK_SIZE / 512) * blocks;
 271         pr_debug("AFFS: initial blksize=%d, blocks=%d\n", 512, blocks);
 272
 273         affs_set_blocksize(sb, PAGE_SIZE);
 274         /* Try to find root block. Its location depends on the block size. */
 275
 276         i = 512;
 277         j = 4096;
 278         if (blocksize > 0) {
 279                 i = j = blocksize;
 280                 size = size / (blocksize / 512);
 281         }
 282         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
 283                 AFFS_SB->s_root_block = root_block;
 284                 if (root_block < 0)
 285                         AFFS_SB->s_root_block = (reserved + size - 1) / 2;
 286                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
 287                 affs_set_blocksize(sb, blocksize);
 288                 AFFS_SB->s_partition_size = size;
 289
 290                 /* The root block location that was calculated above is not
 291                  * correct if the partition size is an odd number of 512-
 292                  * byte blocks, which will be rounded down to a number of
 293                  * 1024-byte blocks, and if there were an even number of
 294                  * reserved blocks. Ideally, all partition checkers should
 295                  * report the real number of blocks of the real blocksize,
 296                  * but since this just cannot be done, we have to try to
 297                  * find the root block anyways. In the above case, it is one
 298                  * block behind the calculated one. So we check this one, too.
 299                  */
 300                 for (num_bm = 0; num_bm < 2; num_bm++) {
 301                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
 302                                 "size=%d, reserved=%d\n",
 303                                 kdevname(dev),
 304                                 AFFS_SB->s_root_block + num_bm,
 305                                 blocksize, size, reserved);
 306                         root_bh = affs_bread(sb, AFFS_SB->s_root_block + num_bm);
 307                         if (!root_bh)
 308                                 continue;
 309                         if (!affs_checksum_block(sb, root_bh) &&
 310                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
 311                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
 312                                 AFFS_SB->s_hashsize    = blocksize / 4 - 56;
 313                                 AFFS_SB->s_root_block += num_bm;
 314                                 key                        = 1;
 315                                 goto got_root;
 316                         }
 317                         affs_brelse(root_bh);
 318                         root_bh = NULL;
 319                 }
 320         }
 321         if (!silent)
 322                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
 323                         kdevname(dev));
 324         goto out_error;
 325
 326         /* N.B. after this point bh must be released */
 327 got_root:
 328         root_block = AFFS_SB->s_root_block;
 329
 330         sb->s_blocksize_bits = blocksize == 512 ? 9 :
 331                                blocksize == 1024 ? 10 :
 332                                blocksize == 2048 ? 11 : 12;
 333
 334         /* Find out which kind of FS we have */
 335         boot_bh = sb_bread(sb, 0);
 336         if (!boot_bh) {
 337                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
 338                 goto out_error;
 339         }
 340         chksum = be32_to_cpu(*(u32 *)boot_bh->b_data);
 341         brelse(boot_bh);
 342
 343         /* Dircache filesystems are compatible with non-dircache ones
 344          * when reading. As long as they aren't supported, writing is
 345          * not recommended.
 346          */
 347         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
 348              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
 349                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
 350                         kdevname(dev));
 351                 sb->s_flags |= MS_RDONLY;
 352         }
 353         switch (chksum) {
 354                 case MUFS_FS:
 355                 case MUFS_INTLFFS:
 356                 case MUFS_DCFFS:
 357                         AFFS_SB->s_flags |= SF_MUFS;
 358                         /* fall thru */
 359                 case FS_INTLFFS:
 360                 case FS_DCFFS:
 361                         AFFS_SB->s_flags |= SF_INTL;
 362                         break;
 363                 case MUFS_FFS:
 364                         AFFS_SB->s_flags |= SF_MUFS;
 365                         break;
 366                 case FS_FFS:
 367                         break;
 368                 case MUFS_OFS:
 369                         AFFS_SB->s_flags |= SF_MUFS;
 370                         /* fall thru */
 371                 case FS_OFS:
 372                         AFFS_SB->s_flags |= SF_OFS;
 373                         sb->s_flags |= MS_NOEXEC;
 374                         break;
 375                 case MUFS_DCOFS:
 376                 case MUFS_INTLOFS:
 377                         AFFS_SB->s_flags |= SF_MUFS;
 378                 case FS_DCOFS:
 379                 case FS_INTLOFS:
 380                         AFFS_SB->s_flags |= SF_INTL | SF_OFS;
 381                         sb->s_flags |= MS_NOEXEC;
 382                         break;
 383                 default:
 384                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
 385                                 kdevname(dev), chksum);
 386                         goto out_error;
 387         }
 388
 389         if (mount_flags & SF_VERBOSE) {
 390                 chksum = cpu_to_be32(chksum);
 391                 printk(KERN_NOTICE "AFFS: Mounting volume \"%*s\": Type=%.3s\\%c, Blocksize=%d\n",
 392                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0],
 393                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
 394                         (char *)&chksum,((char *)&chksum)[3] + '0',blocksize);
 395         }
 396
 397         sb->s_flags |= MS_NODEV | MS_NOSUID;
 398
 399         AFFS_SB->s_data_blksize = sb->s_blocksize;
 400         if (AFFS_SB->s_flags & SF_OFS)
 401                 AFFS_SB->s_data_blksize -= 24;
 402
 403         /* Keep super block in cache */
 404         AFFS_SB->s_root_bh = root_bh;
 405         /* N.B. after this point s_root_bh must be released */
 406
 407         tmp_flags = sb->s_flags;
 408         if (affs_init_bitmap(sb, &tmp_flags))
 409                 goto out_error;
 410         sb->s_flags = tmp_flags;
 411
 412         /* set up enough so that it can read an inode */
 413
 414         root_inode = iget(sb, root_block);
 415         sb->s_root = d_alloc_root(root_inode);
 416         if (!sb->s_root) {
 417                 printk(KERN_ERR "AFFS: Get root inode failed\n");
 418                 goto out_error;
 419         }
 420         sb->s_root->d_op = &affs_dentry_operations;
 421
 422         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
 423         return sb;
 424
 425         /*
 426          * Begin the cascaded cleanup ...
 427          */
 428 out_error:
 429         if (root_inode)
 430                 iput(root_inode);
 431         if (AFFS_SB->s_bitmap)
 432                 kfree(AFFS_SB->s_bitmap);
 433         affs_brelse(root_bh);
 434         if (AFFS_SB->s_prefix)
 435                 kfree(AFFS_SB->s_prefix);
 436         return NULL;
 437 }
 438
 439 static int
 440 affs_remount(struct super_block *sb, int *flags, char *data)
 441 {
 442         int                      blocksize;
 443         uid_t                    uid;
 444         gid_t                    gid;
 445         int                      mode;
 446         int                      reserved;
 447         int                      root_block;
 448         unsigned long            mount_flags;
 449         int                      res = 0;
 450
 451         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
 452
 453         if (!parse_options(data,&uid,&gid,&mode,&reserved,&root_block,
 454             &blocksize,&AFFS_SB->s_prefix,AFFS_SB->s_volume,&mount_flags))
 455                 return -EINVAL;
 456         AFFS_SB->s_flags = mount_flags;
 457         AFFS_SB->s_mode  = mode;
 458         AFFS_SB->s_uid   = uid;
 459         AFFS_SB->s_gid   = gid;
 460
 461         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 462                 return 0;
 463         if (*flags & MS_RDONLY) {
 464                 sb->s_dirt = 1;
 465                 while (sb->s_dirt)
 466                         affs_write_super(sb);
 467                 affs_free_bitmap(sb);
 468         } else
 469                 res = affs_init_bitmap(sb, flags);
 470
 471         return res;
 472 }
 473
 474 static int
 475 affs_statfs(struct super_block *sb, struct statfs *buf)
 476 {
 477         int              free;
 478
 479         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB->s_partition_size,
 480              AFFS_SB->s_reserved);
 481
 482         free          = affs_count_free_blocks(sb);
 483         buf->f_type    = AFFS_SUPER_MAGIC;
 484         buf->f_bsize   = sb->s_blocksize;
 485         buf->f_blocks  = AFFS_SB->s_partition_size - AFFS_SB->s_reserved;
 486         buf->f_bfree   = free;
 487         buf->f_bavail  = free;
 488         return 0;
 489 }
 490
 491 static DECLARE_FSTYPE_DEV(affs_fs_type, "affs", affs_read_super);
 492
 493 static int __init init_affs_fs(void)
 494 {
 495         return register_filesystem(&affs_fs_type);
 496 }
 497
 498 static void __exit exit_affs_fs(void)
 499 {
 500         unregister_filesystem(&affs_fs_type);
 501 }
 502
 503 EXPORT_NO_SYMBOLS;
 504
 505 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
 506 MODULE_LICENSE("GPL");
 507
 508 module_init(init_affs_fs)
 509 module_exit(exit_affs_fs)