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                                                 SLAB_MEM_SPREAD),
  85                                              init_once, NULL);
  86         if (minix_inode_cachep == NULL)
  87                 return -ENOMEM;
  88         return 0;
  89 }
  90
  91 static void destroy_inodecache(void)
  92 {
  93         if (kmem_cache_destroy(minix_inode_cachep))
  94                 printk(KERN_INFO "minix_inode_cache: not all structures were freed\n");
  95 }
  96
  97 static struct super_operations minix_sops = {
  98         .alloc_inode    = minix_alloc_inode,
  99         .destroy_inode  = minix_destroy_inode,
 100         .read_inode     = minix_read_inode,
 101         .write_inode    = minix_write_inode,
 102         .delete_inode   = minix_delete_inode,
 103         .put_super      = minix_put_super,
 104         .statfs         = minix_statfs,
 105         .remount_fs     = minix_remount,
 106 };
 107
 108 static int minix_remount (struct super_block * sb, int * flags, char * data)
 109 {
 110         struct minix_sb_info * sbi = minix_sb(sb);
 111         struct minix_super_block * ms;
 112
 113         ms = sbi->s_ms;
 114         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 115                 return 0;
 116         if (*flags & MS_RDONLY) {
 117                 if (ms->s_state & MINIX_VALID_FS ||
 118                     !(sbi->s_mount_state & MINIX_VALID_FS))
 119                         return 0;
 120                 /* Mounting a rw partition read-only. */
 121                 ms->s_state = sbi->s_mount_state;
 122                 mark_buffer_dirty(sbi->s_sbh);
 123         } else {
 124                 /* Mount a partition which is read-only, read-write. */
 125                 sbi->s_mount_state = ms->s_state;
 126                 ms->s_state &= ~MINIX_VALID_FS;
 127                 mark_buffer_dirty(sbi->s_sbh);
 128
 129                 if (!(sbi->s_mount_state & MINIX_VALID_FS))
 130                         printk("MINIX-fs warning: remounting unchecked fs, "
 131                                 "running fsck is recommended\n");
 132                 else if ((sbi->s_mount_state & MINIX_ERROR_FS))
 133                         printk("MINIX-fs warning: remounting fs with errors, "
 134                                 "running fsck is recommended\n");
 135         }
 136         return 0;
 137 }
 138
 139 static int minix_fill_super(struct super_block *s, void *data, int silent)
 140 {
 141         struct buffer_head *bh;
 142         struct buffer_head **map;
 143         struct minix_super_block *ms;
 144         int i, block;
 145         struct inode *root_inode;
 146         struct minix_sb_info *sbi;
 147
 148         sbi = kmalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
 149         if (!sbi)
 150                 return -ENOMEM;
 151         s->s_fs_info = sbi;
 152         memset(sbi, 0, sizeof(struct minix_sb_info));
 153
 154         /* N.B. These should be compile-time tests.
 155            Unfortunately that is impossible. */
 156         if (32 != sizeof (struct minix_inode))
 157                 panic("bad V1 i-node size");
 158         if (64 != sizeof(struct minix2_inode))
 159                 panic("bad V2 i-node size");
 160
 161         if (!sb_set_blocksize(s, BLOCK_SIZE))
 162                 goto out_bad_hblock;
 163
 164         if (!(bh = sb_bread(s, 1)))
 165                 goto out_bad_sb;
 166
 167         ms = (struct minix_super_block *) bh->b_data;
 168         sbi->s_ms = ms;
 169         sbi->s_sbh = bh;
 170         sbi->s_mount_state = ms->s_state;
 171         sbi->s_ninodes = ms->s_ninodes;
 172         sbi->s_nzones = ms->s_nzones;
 173         sbi->s_imap_blocks = ms->s_imap_blocks;
 174         sbi->s_zmap_blocks = ms->s_zmap_blocks;
 175         sbi->s_firstdatazone = ms->s_firstdatazone;
 176         sbi->s_log_zone_size = ms->s_log_zone_size;
 177         sbi->s_max_size = ms->s_max_size;
 178         s->s_magic = ms->s_magic;
 179         if (s->s_magic == MINIX_SUPER_MAGIC) {
 180                 sbi->s_version = MINIX_V1;
 181                 sbi->s_dirsize = 16;
 182                 sbi->s_namelen = 14;
 183                 sbi->s_link_max = MINIX_LINK_MAX;
 184         } else if (s->s_magic == MINIX_SUPER_MAGIC2) {
 185                 sbi->s_version = MINIX_V1;
 186                 sbi->s_dirsize = 32;
 187                 sbi->s_namelen = 30;
 188                 sbi->s_link_max = MINIX_LINK_MAX;
 189         } else if (s->s_magic == MINIX2_SUPER_MAGIC) {
 190                 sbi->s_version = MINIX_V2;
 191                 sbi->s_nzones = ms->s_zones;
 192                 sbi->s_dirsize = 16;
 193                 sbi->s_namelen = 14;
 194                 sbi->s_link_max = MINIX2_LINK_MAX;
 195         } else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
 196                 sbi->s_version = MINIX_V2;
 197                 sbi->s_nzones = ms->s_zones;
 198                 sbi->s_dirsize = 32;
 199                 sbi->s_namelen = 30;
 200                 sbi->s_link_max = MINIX2_LINK_MAX;
 201         } else
 202                 goto out_no_fs;
 203
 204         /*
 205          * Allocate the buffer map to keep the superblock small.
 206          */
 207         i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
 208         map = kmalloc(i, GFP_KERNEL);
 209         if (!map)
 210                 goto out_no_map;
 211         memset(map, 0, i);
 212         sbi->s_imap = &map[0];
 213         sbi->s_zmap = &map[sbi->s_imap_blocks];
 214
 215         block=2;
 216         for (i=0 ; i < sbi->s_imap_blocks ; i++) {
 217                 if (!(sbi->s_imap[i]=sb_bread(s, block)))
 218                         goto out_no_bitmap;
 219                 block++;
 220         }
 221         for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
 222                 if (!(sbi->s_zmap[i]=sb_bread(s, block)))
 223                         goto out_no_bitmap;
 224                 block++;
 225         }
 226
 227         minix_set_bit(0,sbi->s_imap[0]->b_data);
 228         minix_set_bit(0,sbi->s_zmap[0]->b_data);
 229
 230         /* set up enough so that it can read an inode */
 231         s->s_op = &minix_sops;
 232         root_inode = iget(s, MINIX_ROOT_INO);
 233         if (!root_inode || is_bad_inode(root_inode))
 234                 goto out_no_root;
 235
 236         s->s_root = d_alloc_root(root_inode);
 237         if (!s->s_root)
 238                 goto out_iput;
 239
 240         if (!NO_TRUNCATE)
 241                 s->s_root->d_op = &minix_dentry_operations;
 242
 243         if (!(s->s_flags & MS_RDONLY)) {
 244                 ms->s_state &= ~MINIX_VALID_FS;
 245                 mark_buffer_dirty(bh);
 246         }
 247         if (!(sbi->s_mount_state & MINIX_VALID_FS))
 248                 printk("MINIX-fs: mounting unchecked file system, "
 249                         "running fsck is recommended\n");
 250         else if (sbi->s_mount_state & MINIX_ERROR_FS)
 251                 printk("MINIX-fs: mounting file system with errors, "
 252                         "running fsck is recommended\n");
 253         return 0;
 254
 255 out_iput:
 256         iput(root_inode);
 257         goto out_freemap;
 258
 259 out_no_root:
 260         if (!silent)
 261                 printk("MINIX-fs: get root inode failed\n");
 262         goto out_freemap;
 263
 264 out_no_bitmap:
 265         printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
 266     out_freemap:
 267         for (i = 0; i < sbi->s_imap_blocks; i++)
 268                 brelse(sbi->s_imap[i]);
 269         for (i = 0; i < sbi->s_zmap_blocks; i++)
 270                 brelse(sbi->s_zmap[i]);
 271         kfree(sbi->s_imap);
 272         goto out_release;
 273
 274 out_no_map:
 275         if (!silent)
 276                 printk("MINIX-fs: can't allocate map\n");
 277         goto out_release;
 278
 279 out_no_fs:
 280         if (!silent)
 281                 printk("VFS: Can't find a Minix or Minix V2 filesystem "
 282                         "on device %s\n", s->s_id);
 283     out_release:
 284         brelse(bh);
 285         goto out;
 286
 287 out_bad_hblock:
 288         printk("MINIX-fs: blocksize too small for device\n");
 289         goto out;
 290
 291 out_bad_sb:
 292         printk("MINIX-fs: unable to read superblock\n");
 293  out:
 294         s->s_fs_info = NULL;
 295         kfree(sbi);
 296         return -EINVAL;
 297 }
 298
 299 static int minix_statfs(struct super_block *sb, struct kstatfs *buf)
 300 {
 301         struct minix_sb_info *sbi = minix_sb(sb);
 302         buf->f_type = sb->s_magic;
 303         buf->f_bsize = sb->s_blocksize;
 304         buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
 305         buf->f_bfree = minix_count_free_blocks(sbi);
 306         buf->f_bavail = buf->f_bfree;
 307         buf->f_files = sbi->s_ninodes;
 308         buf->f_ffree = minix_count_free_inodes(sbi);
 309         buf->f_namelen = sbi->s_namelen;
 310         return 0;
 311 }
 312
 313 static int minix_get_block(struct inode *inode, sector_t block,
 314                     struct buffer_head *bh_result, int create)
 315 {
 316         if (INODE_VERSION(inode) == MINIX_V1)
 317                 return V1_minix_get_block(inode, block, bh_result, create);
 318         else
 319                 return V2_minix_get_block(inode, block, bh_result, create);
 320 }
 321
 322 static int minix_writepage(struct page *page, struct writeback_control *wbc)
 323 {
 324         return block_write_full_page(page, minix_get_block, wbc);
 325 }
 326 static int minix_readpage(struct file *file, struct page *page)
 327 {
 328         return block_read_full_page(page,minix_get_block);
 329 }
 330 static int minix_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
 331 {
 332         return block_prepare_write(page,from,to,minix_get_block);
 333 }
 334 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
 335 {
 336         return generic_block_bmap(mapping,block,minix_get_block);
 337 }
 338 static struct address_space_operations minix_aops = {
 339         .readpage = minix_readpage,
 340         .writepage = minix_writepage,
 341         .sync_page = block_sync_page,
 342         .prepare_write = minix_prepare_write,
 343         .commit_write = generic_commit_write,
 344         .bmap = minix_bmap
 345 };
 346
 347 static struct inode_operations minix_symlink_inode_operations = {
 348         .readlink       = generic_readlink,
 349         .follow_link    = page_follow_link_light,
 350         .put_link       = page_put_link,
 351         .getattr        = minix_getattr,
 352 };
 353
 354 void minix_set_inode(struct inode *inode, dev_t rdev)
 355 {
 356         if (S_ISREG(inode->i_mode)) {
 357                 inode->i_op = &minix_file_inode_operations;
 358                 inode->i_fop = &minix_file_operations;
 359                 inode->i_mapping->a_ops = &minix_aops;
 360         } else if (S_ISDIR(inode->i_mode)) {
 361                 inode->i_op = &minix_dir_inode_operations;
 362                 inode->i_fop = &minix_dir_operations;
 363                 inode->i_mapping->a_ops = &minix_aops;
 364         } else if (S_ISLNK(inode->i_mode)) {
 365                 inode->i_op = &minix_symlink_inode_operations;
 366                 inode->i_mapping->a_ops = &minix_aops;
 367         } else
 368                 init_special_inode(inode, inode->i_mode, rdev);
 369 }
 370
 371 /*
 372  * The minix V1 function to read an inode.
 373  */
 374 static void V1_minix_read_inode(struct inode * inode)
 375 {
 376         struct buffer_head * bh;
 377         struct minix_inode * raw_inode;
 378         struct minix_inode_info *minix_inode = minix_i(inode);
 379         int i;
 380
 381         raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
 382         if (!raw_inode) {
 383                 make_bad_inode(inode);
 384                 return;
 385         }
 386         inode->i_mode = raw_inode->i_mode;
 387         inode->i_uid = (uid_t)raw_inode->i_uid;
 388         inode->i_gid = (gid_t)raw_inode->i_gid;
 389         inode->i_nlink = raw_inode->i_nlinks;
 390         inode->i_size = raw_inode->i_size;
 391         inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
 392         inode->i_mtime.tv_nsec = 0;
 393         inode->i_atime.tv_nsec = 0;
 394         inode->i_ctime.tv_nsec = 0;
 395         inode->i_blocks = inode->i_blksize = 0;
 396         for (i = 0; i < 9; i++)
 397                 minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
 398         minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
 399         brelse(bh);
 400 }
 401
 402 /*
 403  * The minix V2 function to read an inode.
 404  */
 405 static void V2_minix_read_inode(struct inode * inode)
 406 {
 407         struct buffer_head * bh;
 408         struct minix2_inode * raw_inode;
 409         struct minix_inode_info *minix_inode = minix_i(inode);
 410         int i;
 411
 412         raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
 413         if (!raw_inode) {
 414                 make_bad_inode(inode);
 415                 return;
 416         }
 417         inode->i_mode = raw_inode->i_mode;
 418         inode->i_uid = (uid_t)raw_inode->i_uid;
 419         inode->i_gid = (gid_t)raw_inode->i_gid;
 420         inode->i_nlink = raw_inode->i_nlinks;
 421         inode->i_size = raw_inode->i_size;
 422         inode->i_mtime.tv_sec = raw_inode->i_mtime;
 423         inode->i_atime.tv_sec = raw_inode->i_atime;
 424         inode->i_ctime.tv_sec = raw_inode->i_ctime;
 425         inode->i_mtime.tv_nsec = 0;
 426         inode->i_atime.tv_nsec = 0;
 427         inode->i_ctime.tv_nsec = 0;
 428         inode->i_blocks = inode->i_blksize = 0;
 429         for (i = 0; i < 10; i++)
 430                 minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
 431         minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
 432         brelse(bh);
 433 }
 434
 435 /*
 436  * The global function to read an inode.
 437  */
 438 static void minix_read_inode(struct inode * inode)
 439 {
 440         if (INODE_VERSION(inode) == MINIX_V1)
 441                 V1_minix_read_inode(inode);
 442         else
 443                 V2_minix_read_inode(inode);
 444 }
 445
 446 /*
 447  * The minix V1 function to synchronize an inode.
 448  */
 449 static struct buffer_head * V1_minix_update_inode(struct inode * inode)
 450 {
 451         struct buffer_head * bh;
 452         struct minix_inode * raw_inode;
 453         struct minix_inode_info *minix_inode = minix_i(inode);
 454         int i;
 455
 456         raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
 457         if (!raw_inode)
 458                 return NULL;
 459         raw_inode->i_mode = inode->i_mode;
 460         raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
 461         raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
 462         raw_inode->i_nlinks = inode->i_nlink;
 463         raw_inode->i_size = inode->i_size;
 464         raw_inode->i_time = inode->i_mtime.tv_sec;
 465         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 466                 raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
 467         else for (i = 0; i < 9; i++)
 468                 raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
 469         mark_buffer_dirty(bh);
 470         return bh;
 471 }
 472
 473 /*
 474  * The minix V2 function to synchronize an inode.
 475  */
 476 static struct buffer_head * V2_minix_update_inode(struct inode * inode)
 477 {
 478         struct buffer_head * bh;
 479         struct minix2_inode * raw_inode;
 480         struct minix_inode_info *minix_inode = minix_i(inode);
 481         int i;
 482
 483         raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
 484         if (!raw_inode)
 485                 return NULL;
 486         raw_inode->i_mode = inode->i_mode;
 487         raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
 488         raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
 489         raw_inode->i_nlinks = inode->i_nlink;
 490         raw_inode->i_size = inode->i_size;
 491         raw_inode->i_mtime = inode->i_mtime.tv_sec;
 492         raw_inode->i_atime = inode->i_atime.tv_sec;
 493         raw_inode->i_ctime = inode->i_ctime.tv_sec;
 494         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 495                 raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
 496         else for (i = 0; i < 10; i++)
 497                 raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
 498         mark_buffer_dirty(bh);
 499         return bh;
 500 }
 501
 502 static struct buffer_head *minix_update_inode(struct inode *inode)
 503 {
 504         if (INODE_VERSION(inode) == MINIX_V1)
 505                 return V1_minix_update_inode(inode);
 506         else
 507                 return V2_minix_update_inode(inode);
 508 }
 509
 510 static int minix_write_inode(struct inode * inode, int wait)
 511 {
 512         brelse(minix_update_inode(inode));
 513         return 0;
 514 }
 515
 516 int minix_sync_inode(struct inode * inode)
 517 {
 518         int err = 0;
 519         struct buffer_head *bh;
 520
 521         bh = minix_update_inode(inode);
 522         if (bh && buffer_dirty(bh))
 523         {
 524                 sync_dirty_buffer(bh);
 525                 if (buffer_req(bh) && !buffer_uptodate(bh))
 526                 {
 527                         printk("IO error syncing minix inode [%s:%08lx]\n",
 528                                 inode->i_sb->s_id, inode->i_ino);
 529                         err = -1;
 530                 }
 531         }
 532         else if (!bh)
 533                 err = -1;
 534         brelse (bh);
 535         return err;
 536 }
 537
 538 int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 539 {
 540         generic_fillattr(dentry->d_inode, stat);
 541         if (INODE_VERSION(dentry->d_inode) == MINIX_V1)
 542                 stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size);
 543         else
 544                 stat->blocks = (BLOCK_SIZE / 512) * V2_minix_blocks(stat->size);
 545         stat->blksize = BLOCK_SIZE;
 546         return 0;
 547 }
 548
 549 /*
 550  * The function that is called for file truncation.
 551  */
 552 void minix_truncate(struct inode * inode)
 553 {
 554         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
 555                 return;
 556         if (INODE_VERSION(inode) == MINIX_V1)
 557                 V1_minix_truncate(inode);
 558         else
 559                 V2_minix_truncate(inode);
 560 }
 561
 562 static struct super_block *minix_get_sb(struct file_system_type *fs_type,
 563         int flags, const char *dev_name, void *data)
 564 {
 565         return get_sb_bdev(fs_type, flags, dev_name, data, minix_fill_super);
 566 }
 567
 568 static struct file_system_type minix_fs_type = {
 569         .owner          = THIS_MODULE,
 570         .name           = "minix",
 571         .get_sb         = minix_get_sb,
 572         .kill_sb        = kill_block_super,
 573         .fs_flags       = FS_REQUIRES_DEV,
 574 };
 575
 576 static int __init init_minix_fs(void)
 577 {
 578         int err = init_inodecache();
 579         if (err)
 580                 goto out1;
 581         err = register_filesystem(&minix_fs_type);
 582         if (err)
 583                 goto out;
 584         return 0;
 585 out:
 586         destroy_inodecache();
 587 out1:
 588         return err;
 589 }
 590
 591 static void __exit exit_minix_fs(void)
 592 {
 593         unregister_filesystem(&minix_fs_type);
 594         destroy_inodecache();
 595 }
 596
 597 module_init(init_minix_fs)
 598 module_exit(exit_minix_fs)
 599 MODULE_LICENSE("GPL");
 600