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