fs/minix/inode.c

   1 /*
   2  *  linux/fs/minix/inode.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  *
   6  *  Copyright (C) 1996  Gertjan van Wingerde    (gertjan@cs.vu.nl)
   7  *      Minix V2 fs support.
   8  *
   9  *  Modified for 680x0 by Andreas Schwab
  10  */
  11
  12 #include <linux/module.h>
  13 #include "minix.h"
  14 #include <linux/buffer_head.h>
  15 #include <linux/slab.h>
  16 #include <linux/init.h>
  17 #include <linux/highuid.h>
  18 #include <linux/vfs.h>
  19
  20 static void minix_read_inode(struct inode * inode);
  21 static int minix_write_inode(struct inode * inode, int wait);
  22 static int minix_statfs(struct super_block *sb, struct kstatfs *buf);
  23 static int minix_remount (struct super_block * sb, int * flags, char * data);
  24
  25 static void minix_delete_inode(struct inode *inode)
  26 {
  27         truncate_inode_pages(&inode->i_data, 0);
  28         inode->i_size = 0;
  29         minix_truncate(inode);
  30         minix_free_inode(inode);
  31 }
  32
  33 static void minix_put_super(struct super_block *sb)
  34 {
  35         int i;
  36         struct minix_sb_info *sbi = minix_sb(sb);
  37
  38         if (!(sb->s_flags & MS_RDONLY)) {
  39                 sbi->s_ms->s_state = sbi->s_mount_state;
  40                 mark_buffer_dirty(sbi->s_sbh);
  41         }
  42         for (i = 0; i < sbi->s_imap_blocks; i++)
  43                 brelse(sbi->s_imap[i]);
  44         for (i = 0; i < sbi->s_zmap_blocks; i++)
  45                 brelse(sbi->s_zmap[i]);
  46         brelse (sbi->s_sbh);
  47         kfree(sbi->s_imap);
  48         sb->s_fs_info = NULL;
  49         kfree(sbi);
  50
  51         return;
  52 }
  53
  54 static kmem_cache_t * minix_inode_cachep;
  55
  56 static struct inode *minix_alloc_inode(struct super_block *sb)
  57 {
  58         struct minix_inode_info *ei;
  59         ei = (struct minix_inode_info *)kmem_cache_alloc(minix_inode_cachep, SLAB_KERNEL);
  60         if (!ei)
  61                 return NULL;
  62         return &ei->vfs_inode;
  63 }
  64
  65 static void minix_destroy_inode(struct inode *inode)
  66 {
  67         kmem_cache_free(minix_inode_cachep, minix_i(inode));
  68 }
  69
  70 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
  71 {
  72         struct minix_inode_info *ei = (struct minix_inode_info *) foo;
  73
  74         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
  75             SLAB_CTOR_CONSTRUCTOR)
  76                 inode_init_once(&ei->vfs_inode);
  77 }
  78
  79 static int init_inodecache(void)
  80 {
  81         minix_inode_cachep = kmem_cache_create("minix_inode_cache",
  82                                              sizeof(struct minix_inode_info),
  83                                              0, SLAB_RECLAIM_ACCOUNT,
  84                                              init_once, NULL);
  85         if (minix_inode_cachep == NULL)
  86                 return -ENOMEM;
  87         return 0;
  88 }
  89
  90 static void destroy_inodecache(void)
  91 {
  92         if (kmem_cache_destroy(minix_inode_cachep))
  93                 printk(KERN_INFO "minix_inode_cache: not all structures were freed\n");
  94 }
  95
  96 static struct super_operations minix_sops = {
  97         .alloc_inode    = minix_alloc_inode,
  98         .destroy_inode  = minix_destroy_inode,
  99         .read_inode     = minix_read_inode,
 100         .write_inode    = minix_write_inode,
 101         .delete_inode   = minix_delete_inode,
 102         .put_super      = minix_put_super,
 103         .statfs         = minix_statfs,
 104         .remount_fs     = minix_remount,
 105 };
 106
 107 static int minix_remount (struct super_block * sb, int * flags, char * data)
 108 {
 109         struct minix_sb_info * sbi = minix_sb(sb);
 110         struct minix_super_block * ms;
 111
 112         ms = sbi->s_ms;
 113         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 114                 return 0;
 115         if (*flags & MS_RDONLY) {
 116                 if (ms->s_state & MINIX_VALID_FS ||
 117                     !(sbi->s_mount_state & MINIX_VALID_FS))
 118                         return 0;
 119                 /* Mounting a rw partition read-only. */
 120                 ms->s_state = sbi->s_mount_state;
 121                 mark_buffer_dirty(sbi->s_sbh);
 122         } else {
 123                 /* Mount a partition which is read-only, read-write. */
 124                 sbi->s_mount_state = ms->s_state;
 125                 ms->s_state &= ~MINIX_VALID_FS;
 126                 mark_buffer_dirty(sbi->s_sbh);
 127
 128                 if (!(sbi->s_mount_state & MINIX_VALID_FS))
 129                         printk ("MINIX-fs warning: remounting unchecked fs, "
 130                                 "running fsck is recommended.\n");
 131                 else if ((sbi->s_mount_state & MINIX_ERROR_FS))
 132                         printk ("MINIX-fs warning: remounting fs with errors, "
 133                                 "running fsck is recommended.\n");
 134         }
 135         return 0;
 136 }
 137
 138 static int minix_fill_super(struct super_block *s, void *data, int silent)
 139 {
 140         struct buffer_head *bh;
 141         struct buffer_head **map;
 142         struct minix_super_block *ms;
 143         int i, block;
 144         struct inode *root_inode;
 145         struct minix_sb_info *sbi;
 146
 147         sbi = kmalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
 148         if (!sbi)
 149                 return -ENOMEM;
 150         s->s_fs_info = sbi;
 151         memset(sbi, 0, sizeof(struct minix_sb_info));
 152
 153         /* N.B. These should be compile-time tests.
 154            Unfortunately that is impossible. */
 155         if (32 != sizeof (struct minix_inode))
 156                 panic("bad V1 i-node size");
 157         if (64 != sizeof(struct minix2_inode))
 158                 panic("bad V2 i-node size");
 159
 160         if (!sb_set_blocksize(s, BLOCK_SIZE))
 161                 goto out_bad_hblock;
 162
 163         if (!(bh = sb_bread(s, 1)))
 164                 goto out_bad_sb;
 165
 166         ms = (struct minix_super_block *) bh->b_data;
 167         sbi->s_ms = ms;
 168         sbi->s_sbh = bh;
 169         sbi->s_mount_state = ms->s_state;
 170         sbi->s_ninodes = ms->s_ninodes;
 171         sbi->s_nzones = ms->s_nzones;
 172         sbi->s_imap_blocks = ms->s_imap_blocks;
 173         sbi->s_zmap_blocks = ms->s_zmap_blocks;
 174         sbi->s_firstdatazone = ms->s_firstdatazone;
 175         sbi->s_log_zone_size = ms->s_log_zone_size;
 176         sbi->s_max_size = ms->s_max_size;
 177         s->s_magic = ms->s_magic;
 178         if (s->s_magic == MINIX_SUPER_MAGIC) {
 179                 sbi->s_version = MINIX_V1;
 180                 sbi->s_dirsize = 16;
 181                 sbi->s_namelen = 14;
 182                 sbi->s_link_max = MINIX_LINK_MAX;
 183         } else if (s->s_magic == MINIX_SUPER_MAGIC2) {
 184                 sbi->s_version = MINIX_V1;
 185                 sbi->s_dirsize = 32;
 186                 sbi->s_namelen = 30;
 187                 sbi->s_link_max = MINIX_LINK_MAX;
 188         } else if (s->s_magic == MINIX2_SUPER_MAGIC) {
 189                 sbi->s_version = MINIX_V2;
 190                 sbi->s_nzones = ms->s_zones;
 191                 sbi->s_dirsize = 16;
 192                 sbi->s_namelen = 14;
 193                 sbi->s_link_max = MINIX2_LINK_MAX;
 194         } else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
 195                 sbi->s_version = MINIX_V2;
 196                 sbi->s_nzones = ms->s_zones;
 197                 sbi->s_dirsize = 32;
 198                 sbi->s_namelen = 30;
 199                 sbi->s_link_max = MINIX2_LINK_MAX;
 200         } else
 201                 goto out_no_fs;
 202
 203         /*
 204          * Allocate the buffer map to keep the superblock small.
 205          */
 206         i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
 207         map = kmalloc(i, GFP_KERNEL);
 208         if (!map)
 209                 goto out_no_map;
 210         memset(map, 0, i);
 211         sbi->s_imap = &map[0];
 212         sbi->s_zmap = &map[sbi->s_imap_blocks];
 213
 214         block=2;
 215         for (i=0 ; i < sbi->s_imap_blocks ; i++) {
 216                 if (!(sbi->s_imap[i]=sb_bread(s, block)))
 217                         goto out_no_bitmap;
 218                 block++;
 219         }
 220         for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
 221                 if (!(sbi->s_zmap[i]=sb_bread(s, block)))
 222                         goto out_no_bitmap;
 223                 block++;
 224         }
 225
 226         minix_set_bit(0,sbi->s_imap[0]->b_data);
 227         minix_set_bit(0,sbi->s_zmap[0]->b_data);
 228
 229         /* set up enough so that it can read an inode */
 230         s->s_op = &minix_sops;
 231         root_inode = iget(s, MINIX_ROOT_INO);
 232         if (!root_inode || is_bad_inode(root_inode))
 233                 goto out_no_root;
 234
 235         s->s_root = d_alloc_root(root_inode);
 236         if (!s->s_root)
 237                 goto out_iput;
 238
 239         if (!NO_TRUNCATE)
 240                 s->s_root->d_op = &minix_dentry_operations;
 241
 242         if (!(s->s_flags & MS_RDONLY)) {
 243                 ms->s_state &= ~MINIX_VALID_FS;
 244                 mark_buffer_dirty(bh);
 245         }
 246         if (!(sbi->s_mount_state & MINIX_VALID_FS))
 247                 printk ("MINIX-fs: mounting unchecked file system, "
 248                         "running fsck is recommended.\n");
 249         else if (sbi->s_mount_state & MINIX_ERROR_FS)
 250                 printk ("MINIX-fs: mounting file system with errors, "
 251                         "running fsck is recommended.\n");
 252         return 0;
 253
 254 out_iput:
 255         iput(root_inode);
 256         goto out_freemap;
 257
 258 out_no_root:
 259         if (!silent)
 260                 printk("MINIX-fs: get root inode failed\n");
 261         goto out_freemap;
 262
 263 out_no_bitmap:
 264         printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
 265     out_freemap:
 266         for (i = 0; i < sbi->s_imap_blocks; i++)
 267                 brelse(sbi->s_imap[i]);
 268         for (i = 0; i < sbi->s_zmap_blocks; i++)
 269                 brelse(sbi->s_zmap[i]);
 270         kfree(sbi->s_imap);
 271         goto out_release;
 272
 273 out_no_map:
 274         if (!silent)
 275                 printk ("MINIX-fs: can't allocate map\n");
 276         goto out_release;
 277
 278 out_no_fs:
 279         if (!silent)
 280                 printk("VFS: Can't find a Minix or Minix V2 filesystem on device "
 281                        "%s.\n", s->s_id);
 282     out_release:
 283         brelse(bh);
 284         goto out;
 285
 286 out_bad_hblock:
 287         printk("MINIX-fs: blocksize too small for device.\n");
 288         goto out;
 289
 290 out_bad_sb:
 291         printk("MINIX-fs: unable to read superblock\n");
 292  out:
 293         s->s_fs_info = NULL;
 294         kfree(sbi);
 295         return -EINVAL;
 296 }
 297
 298 static int minix_statfs(struct super_block *sb, struct kstatfs *buf)
 299 {
 300         struct minix_sb_info *sbi = minix_sb(sb);
 301         buf->f_type = sb->s_magic;
 302         buf->f_bsize = sb->s_blocksize;
 303         buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
 304         buf->f_bfree = minix_count_free_blocks(sbi);
 305         buf->f_bavail = buf->f_bfree;
 306         buf->f_files = sbi->s_ninodes;
 307         buf->f_ffree = minix_count_free_inodes(sbi);
 308         buf->f_namelen = sbi->s_namelen;
 309         return 0;
 310 }
 311
 312 static int minix_get_block(struct inode *inode, sector_t block,
 313                     struct buffer_head *bh_result, int create)
 314 {
 315         if (INODE_VERSION(inode) == MINIX_V1)
 316                 return V1_minix_get_block(inode, block, bh_result, create);
 317         else
 318                 return V2_minix_get_block(inode, block, bh_result, create);
 319 }
 320
 321 static int minix_writepage(struct page *page, struct writeback_control *wbc)
 322 {
 323         return block_write_full_page(page, minix_get_block, wbc);
 324 }
 325 static int minix_readpage(struct file *file, struct page *page)
 326 {
 327         return block_read_full_page(page,minix_get_block);
 328 }
 329 static int minix_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
 330 {
 331         return block_prepare_write(page,from,to,minix_get_block);
 332 }
 333 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
 334 {
 335         return generic_block_bmap(mapping,block,minix_get_block);
 336 }
 337 static struct address_space_operations minix_aops = {
 338         .readpage = minix_readpage,
 339         .writepage = minix_writepage,
 340         .sync_page = block_sync_page,
 341         .prepare_write = minix_prepare_write,
 342         .commit_write = generic_commit_write,
 343         .bmap = minix_bmap
 344 };
 345
 346 static struct inode_operations minix_symlink_inode_operations = {
 347         .readlink       = generic_readlink,
 348         .follow_link    = page_follow_link_light,
 349         .put_link       = page_put_link,
 350         .getattr        = minix_getattr,
 351 };
 352
 353 void minix_set_inode(struct inode *inode, dev_t rdev)
 354 {
 355         if (S_ISREG(inode->i_mode)) {
 356                 inode->i_op = &minix_file_inode_operations;
 357                 inode->i_fop = &minix_file_operations;
 358                 inode->i_mapping->a_ops = &minix_aops;
 359         } else if (S_ISDIR(inode->i_mode)) {
 360                 inode->i_op = &minix_dir_inode_operations;
 361                 inode->i_fop = &minix_dir_operations;
 362                 inode->i_mapping->a_ops = &minix_aops;
 363         } else if (S_ISLNK(inode->i_mode)) {
 364                 inode->i_op = &minix_symlink_inode_operations;
 365                 inode->i_mapping->a_ops = &minix_aops;
 366         } else
 367                 init_special_inode(inode, inode->i_mode, rdev);
 368 }
 369
 370 /*
 371  * The minix V1 function to read an inode.
 372  */
 373 static void V1_minix_read_inode(struct inode * inode)
 374 {
 375         struct buffer_head * bh;
 376         struct minix_inode * raw_inode;
 377         struct minix_inode_info *minix_inode = minix_i(inode);
 378         int i;
 379
 380         raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
 381         if (!raw_inode) {
 382                 make_bad_inode(inode);
 383                 return;
 384         }
 385         inode->i_mode = raw_inode->i_mode;
 386         inode->i_uid = (uid_t)raw_inode->i_uid;
 387         inode->i_gid = (gid_t)raw_inode->i_gid;
 388         inode->i_nlink = raw_inode->i_nlinks;
 389         inode->i_size = raw_inode->i_size;
 390         inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
 391         inode->i_mtime.tv_nsec = 0;
 392         inode->i_atime.tv_nsec = 0;
 393         inode->i_ctime.tv_nsec = 0;
 394         inode->i_blocks = inode->i_blksize = 0;
 395         for (i = 0; i < 9; i++)
 396                 minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
 397         minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
 398         brelse(bh);
 399 }
 400
 401 /*
 402  * The minix V2 function to read an inode.
 403  */
 404 static void V2_minix_read_inode(struct inode * inode)
 405 {
 406         struct buffer_head * bh;
 407         struct minix2_inode * raw_inode;
 408         struct minix_inode_info *minix_inode = minix_i(inode);
 409         int i;
 410
 411         raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
 412         if (!raw_inode) {
 413                 make_bad_inode(inode);
 414                 return;
 415         }
 416         inode->i_mode = raw_inode->i_mode;
 417         inode->i_uid = (uid_t)raw_inode->i_uid;
 418         inode->i_gid = (gid_t)raw_inode->i_gid;
 419         inode->i_nlink = raw_inode->i_nlinks;
 420         inode->i_size = raw_inode->i_size;
 421         inode->i_mtime.tv_sec = raw_inode->i_mtime;
 422         inode->i_atime.tv_sec = raw_inode->i_atime;
 423         inode->i_ctime.tv_sec = raw_inode->i_ctime;
 424         inode->i_mtime.tv_nsec = 0;
 425         inode->i_atime.tv_nsec = 0;
 426         inode->i_ctime.tv_nsec = 0;
 427         inode->i_blocks = inode->i_blksize = 0;
 428         for (i = 0; i < 10; i++)
 429                 minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
 430         minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
 431         brelse(bh);
 432 }
 433
 434 /*
 435  * The global function to read an inode.
 436  */
 437 static void minix_read_inode(struct inode * inode)
 438 {
 439         if (INODE_VERSION(inode) == MINIX_V1)
 440                 V1_minix_read_inode(inode);
 441         else
 442                 V2_minix_read_inode(inode);
 443 }
 444
 445 /*
 446  * The minix V1 function to synchronize an inode.
 447  */
 448 static struct buffer_head * V1_minix_update_inode(struct inode * inode)
 449 {
 450         struct buffer_head * bh;
 451         struct minix_inode * raw_inode;
 452         struct minix_inode_info *minix_inode = minix_i(inode);
 453         int i;
 454
 455         raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
 456         if (!raw_inode)
 457                 return NULL;
 458         raw_inode->i_mode = inode->i_mode;
 459         raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
 460         raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
 461         raw_inode->i_nlinks = inode->i_nlink;
 462         raw_inode->i_size = inode->i_size;
 463         raw_inode->i_time = inode->i_mtime.tv_sec;
 464         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 465                 raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
 466         else for (i = 0; i < 9; i++)
 467                 raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
 468         mark_buffer_dirty(bh);
 469         return bh;
 470 }
 471
 472 /*
 473  * The minix V2 function to synchronize an inode.
 474  */
 475 static struct buffer_head * V2_minix_update_inode(struct inode * inode)
 476 {
 477         struct buffer_head * bh;
 478         struct minix2_inode * raw_inode;
 479         struct minix_inode_info *minix_inode = minix_i(inode);
 480         int i;
 481
 482         raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
 483         if (!raw_inode)
 484                 return NULL;
 485         raw_inode->i_mode = inode->i_mode;
 486         raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
 487         raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
 488         raw_inode->i_nlinks = inode->i_nlink;
 489         raw_inode->i_size = inode->i_size;
 490         raw_inode->i_mtime = inode->i_mtime.tv_sec;
 491         raw_inode->i_atime = inode->i_atime.tv_sec;
 492         raw_inode->i_ctime = inode->i_ctime.tv_sec;
 493         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 494                 raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
 495         else for (i = 0; i < 10; i++)
 496                 raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
 497         mark_buffer_dirty(bh);
 498         return bh;
 499 }
 500
 501 static struct buffer_head *minix_update_inode(struct inode *inode)
 502 {
 503         if (INODE_VERSION(inode) == MINIX_V1)
 504                 return V1_minix_update_inode(inode);
 505         else
 506                 return V2_minix_update_inode(inode);
 507 }
 508
 509 static int minix_write_inode(struct inode * inode, int wait)
 510 {
 511         brelse(minix_update_inode(inode));
 512         return 0;
 513 }
 514
 515 int minix_sync_inode(struct inode * inode)
 516 {
 517         int err = 0;
 518         struct buffer_head *bh;
 519
 520         bh = minix_update_inode(inode);
 521         if (bh && buffer_dirty(bh))
 522         {
 523                 sync_dirty_buffer(bh);
 524                 if (buffer_req(bh) && !buffer_uptodate(bh))
 525                 {
 526                         printk ("IO error syncing minix inode [%s:%08lx]\n",
 527                                 inode->i_sb->s_id, inode->i_ino);
 528                         err = -1;
 529                 }
 530         }
 531         else if (!bh)
 532                 err = -1;
 533         brelse (bh);
 534         return err;
 535 }
 536
 537 int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 538 {
 539         generic_fillattr(dentry->d_inode, stat);
 540         if (INODE_VERSION(dentry->d_inode) == MINIX_V1)
 541                 stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size);
 542         else
 543                 stat->blocks = (BLOCK_SIZE / 512) * V2_minix_blocks(stat->size);
 544         stat->blksize = BLOCK_SIZE;
 545         return 0;
 546 }
 547
 548 /*
 549  * The function that is called for file truncation.
 550  */
 551 void minix_truncate(struct inode * inode)
 552 {
 553         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
 554                 return;
 555         if (INODE_VERSION(inode) == MINIX_V1)
 556                 V1_minix_truncate(inode);
 557         else
 558                 V2_minix_truncate(inode);
 559 }
 560
 561 static struct super_block *minix_get_sb(struct file_system_type *fs_type,
 562         int flags, const char *dev_name, void *data)
 563 {
 564         return get_sb_bdev(fs_type, flags, dev_name, data, minix_fill_super);
 565 }
 566
 567 static struct file_system_type minix_fs_type = {
 568         .owner          = THIS_MODULE,
 569         .name           = "minix",
 570         .get_sb         = minix_get_sb,
 571         .kill_sb        = kill_block_super,
 572         .fs_flags       = FS_REQUIRES_DEV,
 573 };
 574
 575 static int __init init_minix_fs(void)
 576 {
 577         int err = init_inodecache();
 578         if (err)
 579                 goto out1;
 580         err = register_filesystem(&minix_fs_type);
 581         if (err)
 582                 goto out;
 583         return 0;
 584 out:
 585         destroy_inodecache();
 586 out1:
 587         return err;
 588 }
 589
 590 static void __exit exit_minix_fs(void)
 591 {
 592         unregister_filesystem(&minix_fs_type);
 593         destroy_inodecache();
 594 }
 595
 596 module_init(init_minix_fs)
 597 module_exit(exit_minix_fs)
 598 MODULE_LICENSE("GPL");
 599