fs/bfs/inode.c

   1 /*
   2  *      fs/bfs/inode.c
   3  *      BFS superblock and inode operations.
   4  *      Copyright (C) 1999-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
   5  *      From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
   6  *
   7  *      Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/mm.h>
  12 #include <linux/slab.h>
  13 #include <linux/init.h>
  14 #include <linux/fs.h>
  15 #include <linux/buffer_head.h>
  16 #include <linux/vfs.h>
  17 #include <linux/writeback.h>
  18 #include <asm/uaccess.h>
  19 #include "bfs.h"
  20
  21 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
  22 MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
  23 MODULE_LICENSE("GPL");
  24
  25 #undef DEBUG
  26
  27 #ifdef DEBUG
  28 #define dprintf(x...)   printf(x)
  29 #else
  30 #define dprintf(x...)
  31 #endif
  32
  33 void dump_imap(const char *prefix, struct super_block *s);
  34
  35 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
  36 {
  37         struct bfs_inode *di;
  38         struct inode *inode;
  39         struct buffer_head *bh;
  40         int block, off;
  41
  42         inode = iget_locked(sb, ino);
  43         if (IS_ERR(inode))
  44                 return ERR_PTR(-ENOMEM);
  45         if (!(inode->i_state & I_NEW))
  46                 return inode;
  47
  48         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
  49                 printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
  50                 goto error;
  51         }
  52
  53         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
  54         bh = sb_bread(inode->i_sb, block);
  55         if (!bh) {
  56                 printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
  57                                                                         ino);
  58                 goto error;
  59         }
  60
  61         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
  62         di = (struct bfs_inode *)bh->b_data + off;
  63
  64         inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
  65         if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
  66                 inode->i_mode |= S_IFDIR;
  67                 inode->i_op = &bfs_dir_inops;
  68                 inode->i_fop = &bfs_dir_operations;
  69         } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
  70                 inode->i_mode |= S_IFREG;
  71                 inode->i_op = &bfs_file_inops;
  72                 inode->i_fop = &bfs_file_operations;
  73                 inode->i_mapping->a_ops = &bfs_aops;
  74         }
  75
  76         BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
  77         BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
  78         BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
  79         inode->i_uid =  le32_to_cpu(di->i_uid);
  80         inode->i_gid =  le32_to_cpu(di->i_gid);
  81         set_nlink(inode, le32_to_cpu(di->i_nlink));
  82         inode->i_size = BFS_FILESIZE(di);
  83         inode->i_blocks = BFS_FILEBLOCKS(di);
  84         inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
  85         inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
  86         inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
  87         inode->i_atime.tv_nsec = 0;
  88         inode->i_mtime.tv_nsec = 0;
  89         inode->i_ctime.tv_nsec = 0;
  90
  91         brelse(bh);
  92         unlock_new_inode(inode);
  93         return inode;
  94
  95 error:
  96         iget_failed(inode);
  97         return ERR_PTR(-EIO);
  98 }
  99
 100 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
 101 {
 102         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
 103                 printf("Bad inode number %s:%08x\n", sb->s_id, ino);
 104                 return ERR_PTR(-EIO);
 105         }
 106
 107         ino -= BFS_ROOT_INO;
 108
 109         *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
 110         if (!*p) {
 111                 printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
 112                 return ERR_PTR(-EIO);
 113         }
 114
 115         return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
 116 }
 117
 118 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 119 {
 120         struct bfs_sb_info *info = BFS_SB(inode->i_sb);
 121         unsigned int ino = (u16)inode->i_ino;
 122         unsigned long i_sblock;
 123         struct bfs_inode *di;
 124         struct buffer_head *bh;
 125         int err = 0;
 126
 127         dprintf("ino=%08x\n", ino);
 128
 129         di = find_inode(inode->i_sb, ino, &bh);
 130         if (IS_ERR(di))
 131                 return PTR_ERR(di);
 132
 133         mutex_lock(&info->bfs_lock);
 134
 135         if (ino == BFS_ROOT_INO)
 136                 di->i_vtype = cpu_to_le32(BFS_VDIR);
 137         else
 138                 di->i_vtype = cpu_to_le32(BFS_VREG);
 139
 140         di->i_ino = cpu_to_le16(ino);
 141         di->i_mode = cpu_to_le32(inode->i_mode);
 142         di->i_uid = cpu_to_le32(inode->i_uid);
 143         di->i_gid = cpu_to_le32(inode->i_gid);
 144         di->i_nlink = cpu_to_le32(inode->i_nlink);
 145         di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
 146         di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
 147         di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
 148         i_sblock = BFS_I(inode)->i_sblock;
 149         di->i_sblock = cpu_to_le32(i_sblock);
 150         di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
 151         di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
 152
 153         mark_buffer_dirty(bh);
 154         if (wbc->sync_mode == WB_SYNC_ALL) {
 155                 sync_dirty_buffer(bh);
 156                 if (buffer_req(bh) && !buffer_uptodate(bh))
 157                         err = -EIO;
 158         }
 159         brelse(bh);
 160         mutex_unlock(&info->bfs_lock);
 161         return err;
 162 }
 163
 164 static void bfs_evict_inode(struct inode *inode)
 165 {
 166         unsigned long ino = inode->i_ino;
 167         struct bfs_inode *di;
 168         struct buffer_head *bh;
 169         struct super_block *s = inode->i_sb;
 170         struct bfs_sb_info *info = BFS_SB(s);
 171         struct bfs_inode_info *bi = BFS_I(inode);
 172
 173         dprintf("ino=%08lx\n", ino);
 174
 175         truncate_inode_pages(&inode->i_data, 0);
 176         invalidate_inode_buffers(inode);
 177         end_writeback(inode);
 178
 179         if (inode->i_nlink)
 180                 return;
 181
 182         di = find_inode(s, inode->i_ino, &bh);
 183         if (IS_ERR(di))
 184                 return;
 185
 186         mutex_lock(&info->bfs_lock);
 187         /* clear on-disk inode */
 188         memset(di, 0, sizeof(struct bfs_inode));
 189         mark_buffer_dirty(bh);
 190         brelse(bh);
 191
 192         if (bi->i_dsk_ino) {
 193                 if (bi->i_sblock)
 194                         info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
 195                 info->si_freei++;
 196                 clear_bit(ino, info->si_imap);
 197                 dump_imap("delete_inode", s);
 198         }
 199
 200         /*
 201          * If this was the last file, make the previous block
 202          * "last block of the last file" even if there is no
 203          * real file there, saves us 1 gap.
 204          */
 205         if (info->si_lf_eblk == bi->i_eblock)
 206                 info->si_lf_eblk = bi->i_sblock - 1;
 207         mutex_unlock(&info->bfs_lock);
 208 }
 209
 210 static void bfs_put_super(struct super_block *s)
 211 {
 212         struct bfs_sb_info *info = BFS_SB(s);
 213
 214         if (!info)
 215                 return;
 216
 217         mutex_destroy(&info->bfs_lock);
 218         kfree(info->si_imap);
 219         kfree(info);
 220         s->s_fs_info = NULL;
 221 }
 222
 223 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 224 {
 225         struct super_block *s = dentry->d_sb;
 226         struct bfs_sb_info *info = BFS_SB(s);
 227         u64 id = huge_encode_dev(s->s_bdev->bd_dev);
 228         buf->f_type = BFS_MAGIC;
 229         buf->f_bsize = s->s_blocksize;
 230         buf->f_blocks = info->si_blocks;
 231         buf->f_bfree = buf->f_bavail = info->si_freeb;
 232         buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
 233         buf->f_ffree = info->si_freei;
 234         buf->f_fsid.val[0] = (u32)id;
 235         buf->f_fsid.val[1] = (u32)(id >> 32);
 236         buf->f_namelen = BFS_NAMELEN;
 237         return 0;
 238 }
 239
 240 static struct kmem_cache *bfs_inode_cachep;
 241
 242 static struct inode *bfs_alloc_inode(struct super_block *sb)
 243 {
 244         struct bfs_inode_info *bi;
 245         bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
 246         if (!bi)
 247                 return NULL;
 248         return &bi->vfs_inode;
 249 }
 250
 251 static void bfs_i_callback(struct rcu_head *head)
 252 {
 253         struct inode *inode = container_of(head, struct inode, i_rcu);
 254         INIT_LIST_HEAD(&inode->i_dentry);
 255         kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 256 }
 257
 258 static void bfs_destroy_inode(struct inode *inode)
 259 {
 260         call_rcu(&inode->i_rcu, bfs_i_callback);
 261 }
 262
 263 static void init_once(void *foo)
 264 {
 265         struct bfs_inode_info *bi = foo;
 266
 267         inode_init_once(&bi->vfs_inode);
 268 }
 269
 270 static int init_inodecache(void)
 271 {
 272         bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
 273                                              sizeof(struct bfs_inode_info),
 274                                              0, (SLAB_RECLAIM_ACCOUNT|
 275                                                 SLAB_MEM_SPREAD),
 276                                              init_once);
 277         if (bfs_inode_cachep == NULL)
 278                 return -ENOMEM;
 279         return 0;
 280 }
 281
 282 static void destroy_inodecache(void)
 283 {
 284         kmem_cache_destroy(bfs_inode_cachep);
 285 }
 286
 287 static const struct super_operations bfs_sops = {
 288         .alloc_inode    = bfs_alloc_inode,
 289         .destroy_inode  = bfs_destroy_inode,
 290         .write_inode    = bfs_write_inode,
 291         .evict_inode    = bfs_evict_inode,
 292         .put_super      = bfs_put_super,
 293         .statfs         = bfs_statfs,
 294 };
 295
 296 void dump_imap(const char *prefix, struct super_block *s)
 297 {
 298 #ifdef DEBUG
 299         int i;
 300         char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
 301
 302         if (!tmpbuf)
 303                 return;
 304         for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
 305                 if (i > PAGE_SIZE - 100) break;
 306                 if (test_bit(i, BFS_SB(s)->si_imap))
 307                         strcat(tmpbuf, "1");
 308                 else
 309                         strcat(tmpbuf, "0");
 310         }
 311         printf("BFS-fs: %s: lasti=%08lx <%s>\n",
 312                                 prefix, BFS_SB(s)->si_lasti, tmpbuf);
 313         free_page((unsigned long)tmpbuf);
 314 #endif
 315 }
 316
 317 static int bfs_fill_super(struct super_block *s, void *data, int silent)
 318 {
 319         struct buffer_head *bh, *sbh;
 320         struct bfs_super_block *bfs_sb;
 321         struct inode *inode;
 322         unsigned i, imap_len;
 323         struct bfs_sb_info *info;
 324         int ret = -EINVAL;
 325         unsigned long i_sblock, i_eblock, i_eoff, s_size;
 326
 327         info = kzalloc(sizeof(*info), GFP_KERNEL);
 328         if (!info)
 329                 return -ENOMEM;
 330         mutex_init(&info->bfs_lock);
 331         s->s_fs_info = info;
 332
 333         sb_set_blocksize(s, BFS_BSIZE);
 334
 335         sbh = sb_bread(s, 0);
 336         if (!sbh)
 337                 goto out;
 338         bfs_sb = (struct bfs_super_block *)sbh->b_data;
 339         if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
 340                 if (!silent)
 341                         printf("No BFS filesystem on %s (magic=%08x)\n",
 342                                 s->s_id,  le32_to_cpu(bfs_sb->s_magic));
 343                 goto out1;
 344         }
 345         if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 346                 printf("%s is unclean, continuing\n", s->s_id);
 347
 348         s->s_magic = BFS_MAGIC;
 349
 350         if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
 351                 printf("Superblock is corrupted\n");
 352                 goto out1;
 353         }
 354
 355         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
 356                                         sizeof(struct bfs_inode)
 357                                         + BFS_ROOT_INO - 1;
 358         imap_len = (info->si_lasti / 8) + 1;
 359         info->si_imap = kzalloc(imap_len, GFP_KERNEL);
 360         if (!info->si_imap)
 361                 goto out1;
 362         for (i = 0; i < BFS_ROOT_INO; i++)
 363                 set_bit(i, info->si_imap);
 364
 365         s->s_op = &bfs_sops;
 366         inode = bfs_iget(s, BFS_ROOT_INO);
 367         if (IS_ERR(inode)) {
 368                 ret = PTR_ERR(inode);
 369                 goto out2;
 370         }
 371         s->s_root = d_alloc_root(inode);
 372         if (!s->s_root) {
 373                 iput(inode);
 374                 ret = -ENOMEM;
 375                 goto out2;
 376         }
 377
 378         info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
 379         info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
 380                         - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
 381         info->si_freei = 0;
 382         info->si_lf_eblk = 0;
 383
 384         /* can we read the last block? */
 385         bh = sb_bread(s, info->si_blocks - 1);
 386         if (!bh) {
 387                 printf("Last block not available: %lu\n", info->si_blocks - 1);
 388                 ret = -EIO;
 389                 goto out3;
 390         }
 391         brelse(bh);
 392
 393         bh = NULL;
 394         for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
 395                 struct bfs_inode *di;
 396                 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 397                 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 398                 unsigned long eblock;
 399
 400                 if (!off) {
 401                         brelse(bh);
 402                         bh = sb_bread(s, block);
 403                 }
 404
 405                 if (!bh)
 406                         continue;
 407
 408                 di = (struct bfs_inode *)bh->b_data + off;
 409
 410                 /* test if filesystem is not corrupted */
 411
 412                 i_eoff = le32_to_cpu(di->i_eoffset);
 413                 i_sblock = le32_to_cpu(di->i_sblock);
 414                 i_eblock = le32_to_cpu(di->i_eblock);
 415                 s_size = le32_to_cpu(bfs_sb->s_end);
 416
 417                 if (i_sblock > info->si_blocks ||
 418                         i_eblock > info->si_blocks ||
 419                         i_sblock > i_eblock ||
 420                         i_eoff > s_size ||
 421                         i_sblock * BFS_BSIZE > i_eoff) {
 422
 423                         printf("Inode 0x%08x corrupted\n", i);
 424
 425                         brelse(bh);
 426                         ret = -EIO;
 427                         goto out3;
 428                 }
 429
 430                 if (!di->i_ino) {
 431                         info->si_freei++;
 432                         continue;
 433                 }
 434                 set_bit(i, info->si_imap);
 435                 info->si_freeb -= BFS_FILEBLOCKS(di);
 436
 437                 eblock =  le32_to_cpu(di->i_eblock);
 438                 if (eblock > info->si_lf_eblk)
 439                         info->si_lf_eblk = eblock;
 440         }
 441         brelse(bh);
 442         brelse(sbh);
 443         dump_imap("read_super", s);
 444         return 0;
 445
 446 out3:
 447         dput(s->s_root);
 448         s->s_root = NULL;
 449 out2:
 450         kfree(info->si_imap);
 451 out1:
 452         brelse(sbh);
 453 out:
 454         mutex_destroy(&info->bfs_lock);
 455         kfree(info);
 456         s->s_fs_info = NULL;
 457         return ret;
 458 }
 459
 460 static struct dentry *bfs_mount(struct file_system_type *fs_type,
 461         int flags, const char *dev_name, void *data)
 462 {
 463         return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
 464 }
 465
 466 static struct file_system_type bfs_fs_type = {
 467         .owner          = THIS_MODULE,
 468         .name           = "bfs",
 469         .mount          = bfs_mount,
 470         .kill_sb        = kill_block_super,
 471         .fs_flags       = FS_REQUIRES_DEV,
 472 };
 473
 474 static int __init init_bfs_fs(void)
 475 {
 476         int err = init_inodecache();
 477         if (err)
 478                 goto out1;
 479         err = register_filesystem(&bfs_fs_type);
 480         if (err)
 481                 goto out;
 482         return 0;
 483 out:
 484         destroy_inodecache();
 485 out1:
 486         return err;
 487 }
 488
 489 static void __exit exit_bfs_fs(void)
 490 {
 491         unregister_filesystem(&bfs_fs_type);
 492         destroy_inodecache();
 493 }
 494
 495 module_init(init_bfs_fs)
 496 module_exit(exit_bfs_fs)