fs/msdos/inode.c

/* */
This source file includes following definitions.
msdos_put_inode
msdos_put_super
parse_options
msdos_read_super
msdos_statfs
msdos_bmap
msdos_read_inode
msdos_write_inode
msdos_notify_change
init_module
cleanup_module
   1 /*
   2  *  linux/fs/msdos/inode.c
   3  *
   4  *  Written 1992,1993 by Werner Almesberger
   5  */
   6 
   7 #include <linux/module.h>
   8 
   9 #include <linux/msdos_fs.h>
  10 #include <linux/kernel.h>
  11 #include <linux/sched.h>
  12 #include <linux/errno.h>
  13 #include <linux/string.h>
  14 #include <linux/ctype.h>
  15 #include <linux/major.h>
  16 #include <linux/blkdev.h>
  17 #include <linux/fs.h>
  18 #include <linux/stat.h>
  19 #include <linux/locks.h>
  20 
  21 #include "msbuffer.h"
  22 
  23 #include <asm/segment.h>
  24 
  25 void msdos_put_inode(struct inode *inode)
     /*  */
  26 {
  27         struct inode *depend;
  28         struct super_block *sb;
  29 
  30         if (inode->i_nlink) {
  31                 if (MSDOS_I(inode)->i_busy) cache_inval_inode(inode);
  32                 return;
  33         }
  34         inode->i_size = 0;
  35         msdos_truncate(inode);
  36         depend = MSDOS_I(inode)->i_depend;
  37         sb = inode->i_sb;
  38         clear_inode(inode);
  39         if (depend) {
  40                 if (MSDOS_I(depend)->i_old != inode) {
  41                         printk("Invalid link (0x%p): expected 0x%p, got 0x%p\n",
  42                             depend, inode, MSDOS_I(depend)->i_old);
  43                         fs_panic(sb,"...");
  44                         return;
  45                 }
  46                 MSDOS_I(depend)->i_old = NULL;
  47                 iput(depend);
  48         }
  49 }
  50 
  51 
  52 void msdos_put_super(struct super_block *sb)
     /*  */
  53 {
  54         cache_inval_dev(sb->s_dev);
  55         set_blocksize (sb->s_dev,BLOCK_SIZE);
  56         lock_super(sb);
  57         sb->s_dev = 0;
  58         unlock_super(sb);
  59         MOD_DEC_USE_COUNT;
  60         return;
  61 }
  62 
  63 
  64 static struct super_operations msdos_sops = { 
  65         msdos_read_inode,
  66         msdos_notify_change,
  67         msdos_write_inode,
  68         msdos_put_inode,
  69         msdos_put_super,
  70         NULL, /* added in 0.96c */
  71         msdos_statfs,
  72         NULL
  73 };
  74 
  75 
  76 static int parse_options(char *options,char *check,char *conversion,uid_t *uid,
     /*  */
  77     gid_t *gid,int *umask,int *debug,int *fat,int *quiet,
  78         int *blksize, char *dotsOK)
  79 {
  80         char *this_char,*value;
  81 
  82         *check = 'n';
  83         *conversion = 'b';
  84         /* Please leave dotsOK as 1, and contact Albert Cahalan if */
  85         /* it causes any problems for you. <albert@ccs.neu.edu>    */
  86         *dotsOK =1;  /* see note above, and report problems */
  87         *uid = current->uid;
  88         *gid = current->gid;
  89         *umask = current->fs->umask;
  90         *debug = *fat = *quiet = 0;
  91         if (!options) return 1;
  92         for (this_char = strtok(options,","); this_char; this_char = strtok(NULL,",")) {
  93                 if ((value = strchr(this_char,'=')) != NULL)
  94                         *value++ = 0;
  95                 if (!strcmp(this_char,"check") && value) {
  96                         if (value[0] && !value[1] && strchr("rns",*value))
  97                                 *check = *value;
  98                         else if (!strcmp(value,"relaxed")) *check = 'r';
  99                         else if (!strcmp(value,"normal")) *check = 'n';
 100                         else if (!strcmp(value,"strict")) *check = 's';
 101                         else return 0;
 102                 }
 103                 else if (!strcmp(this_char,"conv") && value) {
 104                         if (value[0] && !value[1] && strchr("bta",*value))
 105                                 *conversion = *value;
 106                         else if (!strcmp(value,"binary")) *conversion = 'b';
 107                         else if (!strcmp(value,"text")) *conversion = 't';
 108                         else if (!strcmp(value,"auto")) *conversion = 'a';
 109                         else return 0;
 110                 }
 111                 else if (!strcmp(this_char,"dotsOK") && value) {
 112                         if (!strcmp(value,"yes")) *dotsOK = 1;
 113                         else if (!strcmp(value,"no")) *dotsOK = 0;
 114                         else return 0;
 115                 }
 116                 else if (!strcmp(this_char,"uid")) {
 117                         if (!value || !*value)
 118                                 return 0;
 119                         *uid = simple_strtoul(value,&value,0);
 120                         if (*value)
 121                                 return 0;
 122                 }
 123                 else if (!strcmp(this_char,"gid")) {
 124                         if (!value || !*value)
 125                                 return 0;
 126                         *gid = simple_strtoul(value,&value,0);
 127                         if (*value)
 128                                 return 0;
 129                 }
 130                 else if (!strcmp(this_char,"umask")) {
 131                         if (!value || !*value)
 132                                 return 0;
 133                         *umask = simple_strtoul(value,&value,8);
 134                         if (*value)
 135                                 return 0;
 136                 }
 137                 else if (!strcmp(this_char,"debug")) {
 138                         if (value) return 0;
 139                         *debug = 1;
 140                 }
 141                 else if (!strcmp(this_char,"fat")) {
 142                         if (!value || !*value)
 143                                 return 0;
 144                         *fat = simple_strtoul(value,&value,0);
 145                         if (*value || (*fat != 12 && *fat != 16))
 146                                 return 0;
 147                 }
 148                 else if (!strcmp(this_char,"quiet")) {
 149                         if (value) return 0;
 150                         *quiet = 1;
 151                 }
 152                 else if (!strcmp(this_char,"blocksize")) {
 153                         *blksize = simple_strtoul(value,&value,0);
 154                         if (*value)
 155                                 return 0;
 156                         if (*blksize != 512 && *blksize != 1024){
 157                                 printk ("MSDOS FS: Invalid blocksize (512 or 1024)\n");
 158                         }
 159                 }
 160                 else return 1;
 161         }
 162         return 1;
 163 }
 164 
 165 
 166 /* Read the super block of an MS-DOS FS. */
 167 
 168 struct super_block *msdos_read_super(struct super_block *sb,void *data,
     /*  */
 169                                      int silent)
 170 {
 171         struct buffer_head *bh;
 172         struct msdos_boot_sector *b;
 173         int data_sectors,logical_sector_size,sector_mult,fat_clusters=0;
 174         int debug,error,fat,quiet;
 175         char check,conversion,dotsOK;
 176         uid_t uid;
 177         gid_t gid;
 178         int umask;
 179         int blksize = 512;
 180 
 181         MOD_INC_USE_COUNT;
 182         if (hardsect_size[MAJOR(sb->s_dev)] != NULL){
 183                 blksize = hardsect_size[MAJOR(sb->s_dev)][MINOR(sb->s_dev)];
 184                 if (blksize != 512){
 185                         printk ("MSDOS: Hardware sector size is %d\n",blksize);
 186                 }
 187         }
 188         if (!parse_options((char *) data,&check,&conversion,&uid,&gid,&umask,
 189             &debug,&fat,&quiet,&blksize,&dotsOK)
 190                 || (blksize != 512 && blksize != 1024)) {
 191                 sb->s_dev = 0;
 192                 MOD_DEC_USE_COUNT;
 193                 return NULL;
 194         }
 195         cache_init();
 196         lock_super(sb);
 197         /* The first read is always 1024 bytes */
 198         sb->s_blocksize = 1024;
 199         set_blocksize(sb->s_dev, 1024);
 200         bh = bread(sb->s_dev, 0, 1024);
 201         unlock_super(sb);
 202         if (bh == NULL || !msdos_is_uptodate(sb,bh)) {
 203                 brelse (bh);
 204                 sb->s_dev = 0;
 205                 printk("MSDOS bread failed\n");
 206                 MOD_DEC_USE_COUNT;
 207                 return NULL;
 208         }
 209         b = (struct msdos_boot_sector *) bh->b_data;
 210         set_blocksize(sb->s_dev, blksize);
 211 /*
 212  * The DOS3 partition size limit is *not* 32M as many people think.  
 213  * Instead, it is 64K sectors (with the usual sector size being
 214  * 512 bytes, leading to a 32M limit).
 215  * 
 216  * DOS 3 partition managers got around this problem by faking a 
 217  * larger sector size, ie treating multiple physical sectors as 
 218  * a single logical sector.
 219  * 
 220  * We can accommodate this scheme by adjusting our cluster size,
 221  * fat_start, and data_start by an appropriate value.
 222  *
 223  * (by Drew Eckhardt)
 224  */
 225 
 226 #define ROUND_TO_MULTIPLE(n,m) ((n) && (m) ? (n)+(m)-1-((n)-1)%(m) : 0)
 227     /* don't divide by zero */
 228 
 229         logical_sector_size = CF_LE_W(*(unsigned short *) &b->sector_size);
 230         sector_mult = logical_sector_size >> SECTOR_BITS;
 231         MSDOS_SB(sb)->cluster_size = b->cluster_size*sector_mult;
 232         MSDOS_SB(sb)->fats = b->fats;
 233         MSDOS_SB(sb)->fat_start = CF_LE_W(b->reserved)*sector_mult;
 234         MSDOS_SB(sb)->fat_length = CF_LE_W(b->fat_length)*sector_mult;
 235         MSDOS_SB(sb)->dir_start = (CF_LE_W(b->reserved)+b->fats*CF_LE_W(
 236             b->fat_length))*sector_mult;
 237         MSDOS_SB(sb)->dir_entries = CF_LE_W(*((unsigned short *) &b->dir_entries
 238             ));
 239         MSDOS_SB(sb)->data_start = MSDOS_SB(sb)->dir_start+ROUND_TO_MULTIPLE((
 240             MSDOS_SB(sb)->dir_entries << MSDOS_DIR_BITS) >> SECTOR_BITS,
 241             sector_mult);
 242         data_sectors = (CF_LE_W(*((unsigned short *) &b->sectors)) ?
 243             CF_LE_W(*((unsigned short *) &b->sectors)) :
 244             CF_LE_L(b->total_sect))*sector_mult-MSDOS_SB(sb)->data_start;
 245         error = !b->cluster_size || !sector_mult;
 246         if (!error) {
 247                 MSDOS_SB(sb)->clusters = b->cluster_size ? data_sectors/
 248                     b->cluster_size/sector_mult : 0;
 249                 MSDOS_SB(sb)->fat_bits = fat ? fat : MSDOS_SB(sb)->clusters >
 250                     MSDOS_FAT12 ? 16 : 12;
 251                 fat_clusters = MSDOS_SB(sb)->fat_length*SECTOR_SIZE*8/
 252                     MSDOS_SB(sb)->fat_bits;
 253                 error = !MSDOS_SB(sb)->fats || (MSDOS_SB(sb)->dir_entries &
 254                     (MSDOS_DPS-1)) || MSDOS_SB(sb)->clusters+2 > fat_clusters+
 255                     MSDOS_MAX_EXTRA || (logical_sector_size & (SECTOR_SIZE-1))
 256                     || !b->secs_track || !b->heads;
 257         }
 258         brelse(bh);
 259         /*
 260                 This must be done after the brelse because the bh is a dummy
 261                 allocated by msdos_bread (see buffer.c)
 262         */
 263         sb->s_blocksize = blksize;      /* Using this small block size solve the */
 264                                 /* the misfit with buffer cache and cluster */
 265                                 /* because cluster (DOS) are often aligned */
 266                                 /* on odd sector */
 267         sb->s_blocksize_bits = blksize == 512 ? 9 : 10;
 268         if (error || debug) {
 269                 /* The MSDOS_CAN_BMAP is obsolete, but left just to remember */
 270                 printk("[MS-DOS FS Rel. 12,FAT %d,check=%c,conv=%c,"
 271                     "uid=%d,gid=%d,umask=%03o%s]\n",MSDOS_SB(sb)->fat_bits,check,
 272                     conversion,uid,gid,umask,MSDOS_CAN_BMAP(MSDOS_SB(sb)) ?
 273                     ",bmap" : "");
 274                 printk("[me=0x%x,cs=%d,#f=%d,fs=%d,fl=%d,ds=%d,de=%d,data=%d,"
 275                     "se=%d,ts=%ld,ls=%d]\n",b->media,MSDOS_SB(sb)->cluster_size,
 276                     MSDOS_SB(sb)->fats,MSDOS_SB(sb)->fat_start,MSDOS_SB(sb)->
 277                     fat_length,MSDOS_SB(sb)->dir_start,MSDOS_SB(sb)->dir_entries,
 278                     MSDOS_SB(sb)->data_start,CF_LE_W(*(unsigned short *) &b->
 279                     sectors),(unsigned long)b->total_sect,logical_sector_size);
 280                 printk ("Transaction block size = %d\n",blksize);
 281         }
 282         if (MSDOS_SB(sb)->clusters+2 > fat_clusters)
 283                 MSDOS_SB(sb)->clusters = fat_clusters-2;
 284         if (error) {
 285                 if (!silent)
 286                         printk("VFS: Can't find a valid MSDOS filesystem on dev "
 287                                "%s.\n", kdevname(sb->s_dev));
 288                 sb->s_dev = 0;
 289                 MOD_DEC_USE_COUNT;
 290                 return NULL;
 291         }
 292         sb->s_magic = MSDOS_SUPER_MAGIC;
 293         MSDOS_SB(sb)->name_check = check;
 294         MSDOS_SB(sb)->conversion = conversion;
 295         /* set up enough so that it can read an inode */
 296         sb->s_op = &msdos_sops;
 297         MSDOS_SB(sb)->fs_uid = uid;
 298         MSDOS_SB(sb)->fs_gid = gid;
 299         MSDOS_SB(sb)->fs_umask = umask;
 300         MSDOS_SB(sb)->quiet = quiet;
 301         MSDOS_SB(sb)->dotsOK = dotsOK;
 302         MSDOS_SB(sb)->free_clusters = -1; /* don't know yet */
 303         MSDOS_SB(sb)->fat_wait = NULL;
 304         MSDOS_SB(sb)->fat_lock = 0;
 305         MSDOS_SB(sb)->prev_free = 0;
 306         if (!(sb->s_mounted = iget(sb,MSDOS_ROOT_INO))) {
 307                 sb->s_dev = 0;
 308                 printk("get root inode failed\n");
 309                 MOD_DEC_USE_COUNT;
 310                 return NULL;
 311         }
 312         return sb;
 313 }
 314 
 315 
 316 void msdos_statfs(struct super_block *sb,struct statfs *buf, int bufsiz)
     /*  */
 317 {
 318         int free,nr;
 319         struct statfs tmp;
 320 
 321         lock_fat(sb);
 322         if (MSDOS_SB(sb)->free_clusters != -1)
 323                 free = MSDOS_SB(sb)->free_clusters;
 324         else {
 325                 free = 0;
 326                 for (nr = 2; nr < MSDOS_SB(sb)->clusters+2; nr++)
 327                         if (!fat_access(sb,nr,-1)) free++;
 328                 MSDOS_SB(sb)->free_clusters = free;
 329         }
 330         unlock_fat(sb);
 331         tmp.f_type = sb->s_magic;
 332         tmp.f_bsize = MSDOS_SB(sb)->cluster_size*SECTOR_SIZE;
 333         tmp.f_blocks = MSDOS_SB(sb)->clusters;
 334         tmp.f_bfree = free;
 335         tmp.f_bavail = free;
 336         tmp.f_files = 0;
 337         tmp.f_ffree = 0;
 338         tmp.f_namelen = 12;
 339         memcpy_tofs(buf, &tmp, bufsiz);
 340 }
 341 
 342 
 343 int msdos_bmap(struct inode *inode,int block)
     /*  */
 344 {
 345         struct msdos_sb_info *sb;
 346         int cluster,offset;
 347 
 348         sb = MSDOS_SB(inode->i_sb);
 349         if (inode->i_ino == MSDOS_ROOT_INO) {
 350                 return sb->dir_start + block;
 351         }
 352         cluster = block/sb->cluster_size;
 353         offset = block % sb->cluster_size;
 354         if (!(cluster = get_cluster(inode,cluster))) return 0;
 355         return (cluster-2)*sb->cluster_size+sb->data_start+offset;
 356 }
 357 
 358 
 359 void msdos_read_inode(struct inode *inode)
     /*  */
 360 {
 361         struct super_block *sb = inode->i_sb;
 362         struct buffer_head *bh;
 363         struct msdos_dir_entry *raw_entry;
 364         int nr;
 365 
 366 /* printk("read inode %d\n",inode->i_ino); */
 367         MSDOS_I(inode)->i_busy = 0;
 368         MSDOS_I(inode)->i_depend = MSDOS_I(inode)->i_old = NULL;
 369         MSDOS_I(inode)->i_binary = 1;
 370         inode->i_uid = MSDOS_SB(inode->i_sb)->fs_uid;
 371         inode->i_gid = MSDOS_SB(inode->i_sb)->fs_gid;
 372         if (inode->i_ino == MSDOS_ROOT_INO) {
 373                 inode->i_mode = (S_IRWXUGO & ~MSDOS_SB(inode->i_sb)->fs_umask) |
 374                     S_IFDIR;
 375                 inode->i_op = &msdos_dir_inode_operations;
 376                 inode->i_nlink = msdos_subdirs(inode)+2;
 377                     /* subdirs (neither . nor ..) plus . and "self" */
 378                 inode->i_size = MSDOS_SB(inode->i_sb)->dir_entries*
 379                     sizeof(struct msdos_dir_entry);
 380                 inode->i_blksize = MSDOS_SB(inode->i_sb)->cluster_size*
 381                     SECTOR_SIZE;
 382                 inode->i_blocks = (inode->i_size+inode->i_blksize-1)/
 383                     inode->i_blksize*MSDOS_SB(inode->i_sb)->cluster_size;
 384                 MSDOS_I(inode)->i_start = 0;
 385                 MSDOS_I(inode)->i_attrs = 0;
 386                 inode->i_mtime = inode->i_atime = inode->i_ctime = 0;
 387                 return;
 388         }
 389         if (!(bh = bread(inode->i_dev,inode->i_ino >> MSDOS_DPB_BITS,
 390             SECTOR_SIZE))) {
 391                 printk("dev = %s, ino = %ld\n",
 392                        kdevname(inode->i_dev), inode->i_ino);
 393                 panic("msdos_read_inode: unable to read i-node block");
 394         }
 395         raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
 396             [inode->i_ino & (MSDOS_DPB-1)];
 397         if ((raw_entry->attr & ATTR_DIR) && !IS_FREE(raw_entry->name)) {
 398                 inode->i_mode = MSDOS_MKMODE(raw_entry->attr,S_IRWXUGO &
 399                     ~MSDOS_SB(inode->i_sb)->fs_umask) | S_IFDIR;
 400                 inode->i_op = &msdos_dir_inode_operations;
 401                 MSDOS_I(inode)->i_start = CF_LE_W(raw_entry->start);
 402                 inode->i_nlink = msdos_subdirs(inode);
 403                     /* includes .., compensating for "self" */
 404 #ifdef DEBUG
 405                 if (!inode->i_nlink) {
 406                         printk("directory %d: i_nlink == 0\n",inode->i_ino);
 407                         inode->i_nlink = 1;
 408                 }
 409 #endif
 410                 inode->i_size = 0;
 411                 if ((nr = CF_LE_W(raw_entry->start)) != 0)
 412                         while (nr != -1) {
 413                                 inode->i_size += SECTOR_SIZE*MSDOS_SB(inode->
 414                                     i_sb)->cluster_size;
 415                                 if (!(nr = fat_access(inode->i_sb,nr,-1))) {
 416                                         printk("Directory %ld: bad FAT\n",
 417                                             inode->i_ino);
 418                                         break;
 419                                 }
 420                         }
 421         } else { /* not a directory */
 422                 inode->i_mode = MSDOS_MKMODE(raw_entry->attr,
 423                     (IS_NOEXEC(inode) ? S_IRUGO|S_IWUGO : S_IRWXUGO)
 424                     & ~MSDOS_SB(inode->i_sb)->fs_umask) | S_IFREG;
 425                 inode->i_op = sb->s_blocksize == 1024
 426                         ? &msdos_file_inode_operations_1024
 427                         : &msdos_file_inode_operations;
 428                 MSDOS_I(inode)->i_start = CF_LE_W(raw_entry->start);
 429                 inode->i_nlink = 1;
 430                 inode->i_size = CF_LE_L(raw_entry->size);
 431         }
 432         if(raw_entry->attr & ATTR_SYS)
 433                 inode->i_flags |= S_IMMUTABLE;
 434         MSDOS_I(inode)->i_binary = is_binary(MSDOS_SB(inode->i_sb)->conversion,
 435             raw_entry->ext);
 436         MSDOS_I(inode)->i_attrs = raw_entry->attr & ATTR_UNUSED;
 437         /* this is as close to the truth as we can get ... */
 438         inode->i_blksize = MSDOS_SB(inode->i_sb)->cluster_size*SECTOR_SIZE;
 439         inode->i_blocks = (inode->i_size+inode->i_blksize-1)/
 440             inode->i_blksize*MSDOS_SB(inode->i_sb)->cluster_size;
 441         inode->i_mtime = inode->i_atime = inode->i_ctime =
 442             date_dos2unix(CF_LE_W(raw_entry->time),CF_LE_W(raw_entry->date));
 443         brelse(bh);
 444 }
 445 
 446 
 447 void msdos_write_inode(struct inode *inode)
     /*  */
 448 {
 449         struct super_block *sb = inode->i_sb;
 450         struct buffer_head *bh;
 451         struct msdos_dir_entry *raw_entry;
 452 
 453         inode->i_dirt = 0;
 454         if (inode->i_ino == MSDOS_ROOT_INO || !inode->i_nlink) return;
 455         if (!(bh = bread(inode->i_dev,inode->i_ino >> MSDOS_DPB_BITS,
 456             SECTOR_SIZE))) {
 457                 printk("dev = %s, ino = %ld\n",
 458                        kdevname(inode->i_dev), inode->i_ino);
 459                 panic("msdos_write_inode: unable to read i-node block");
 460         }
 461         raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
 462             [inode->i_ino & (MSDOS_DPB-1)];
 463         if (S_ISDIR(inode->i_mode)) {
 464                 raw_entry->attr = ATTR_DIR;
 465                 raw_entry->size = 0;
 466         }
 467         else {
 468                 raw_entry->attr = ATTR_NONE;
 469                 raw_entry->size = CT_LE_L(inode->i_size);
 470         }
 471         raw_entry->attr |= MSDOS_MKATTR(inode->i_mode) |
 472             MSDOS_I(inode)->i_attrs;
 473         raw_entry->start = CT_LE_L(MSDOS_I(inode)->i_start);
 474         date_unix2dos(inode->i_mtime,&raw_entry->time,&raw_entry->date);
 475         raw_entry->time = CT_LE_W(raw_entry->time);
 476         raw_entry->date = CT_LE_W(raw_entry->date);
 477         mark_buffer_dirty(bh, 1);
 478         brelse(bh);
 479 }
 480 
 481 
 482 int msdos_notify_change(struct inode * inode,struct iattr * attr)
     /*  */
 483 {
 484         int error;
 485 
 486         error = inode_change_ok(inode, attr);
 487         if (error)
 488                 return error;
 489 
 490         if (((attr->ia_valid & ATTR_UID) && 
 491              (attr->ia_uid != MSDOS_SB(inode->i_sb)->fs_uid)) ||
 492             ((attr->ia_valid & ATTR_GID) && 
 493              (attr->ia_gid != MSDOS_SB(inode->i_sb)->fs_gid)) ||
 494             ((attr->ia_valid & ATTR_MODE) &&
 495              (attr->ia_mode & ~MSDOS_VALID_MODE)))
 496                 error = -EPERM;
 497 
 498         if (error)
 499                 return MSDOS_SB(inode->i_sb)->quiet ? 0 : error;
 500 
 501         inode_setattr(inode, attr);
 502 
 503         if (IS_NOEXEC(inode) && !S_ISDIR(inode->i_mode))
 504                 inode->i_mode &= S_IFMT | S_IRUGO | S_IWUGO;
 505         else
 506                 inode->i_mode |= S_IXUGO;
 507 
 508         inode->i_mode = ((inode->i_mode & S_IFMT) | ((((inode->i_mode & S_IRWXU
 509             & ~MSDOS_SB(inode->i_sb)->fs_umask) | S_IRUSR) >> 6)*S_IXUGO)) &
 510             ~MSDOS_SB(inode->i_sb)->fs_umask;
 511         return 0;
 512 }
 513 
 514 #ifdef MODULE
 515 
 516 static struct file_system_type msdos_fs_type = {
 517         msdos_read_super, "msdos", 1, NULL
 518 };
 519 
 520 int init_module(void)
     /*  */
 521 {
 522         return register_filesystem(&msdos_fs_type);
 523 }
 524 
 525 void cleanup_module(void)
     /*  */
 526 {
 527         unregister_filesystem(&msdos_fs_type);
 528 }
 529 
 530 #endif
 531
/* */
root/fs/msdos/inode.c

DEFINITIONS
