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