1 /* 2 * fs/bfs/inode.c 3 * BFS superblock and inode operations. 4 * Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com> 5 * From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds. 6 * Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005. 7 */ 8 9 #include <linux/module.h> 10 #include <linux/mm.h> 11 #include <linux/slab.h> 12 #include <linux/init.h> 13 #include <linux/fs.h> 14 #include <linux/buffer_head.h> 15 #include <linux/vfs.h> 16 #include <linux/writeback.h> 17 #include <linux/uio.h> 18 #include <linux/uaccess.h> 19 #include "bfs.h" 20 21 MODULE_AUTHOR("Tigran Aivazian <aivazian.tigran@gmail.com>"); 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 struct inode *bfs_iget(struct super_block *sb, unsigned long ino) 34 { 35 struct bfs_inode *di; 36 struct inode *inode; 37 struct buffer_head *bh; 38 int block, off; 39 40 inode = iget_locked(sb, ino); 41 if (!inode) 42 return ERR_PTR(-ENOMEM); 43 if (!(inode->i_state & I_NEW)) 44 return inode; 45 46 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) { 47 printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino); 48 goto error; 49 } 50 51 block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1; 52 bh = sb_bread(inode->i_sb, block); 53 if (!bh) { 54 printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id, 55 ino); 56 goto error; 57 } 58 59 off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK; 60 di = (struct bfs_inode *)bh->b_data + off; 61 62 inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode); 63 if (le32_to_cpu(di->i_vtype) == BFS_VDIR) { 64 inode->i_mode |= S_IFDIR; 65 inode->i_op = &bfs_dir_inops; 66 inode->i_fop = &bfs_dir_operations; 67 } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) { 68 inode->i_mode |= S_IFREG; 69 inode->i_op = &bfs_file_inops; 70 inode->i_fop = &bfs_file_operations; 71 inode->i_mapping->a_ops = &bfs_aops; 72 } 73 74 BFS_I(inode)->i_sblock = le32_to_cpu(di->i_sblock); 75 BFS_I(inode)->i_eblock = le32_to_cpu(di->i_eblock); 76 BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino); 77 i_uid_write(inode, le32_to_cpu(di->i_uid)); 78 i_gid_write(inode, le32_to_cpu(di->i_gid)); 79 set_nlink(inode, le32_to_cpu(di->i_nlink)); 80 inode->i_size = BFS_FILESIZE(di); 81 inode->i_blocks = BFS_FILEBLOCKS(di); 82 inode->i_atime.tv_sec = le32_to_cpu(di->i_atime); 83 inode->i_mtime.tv_sec = le32_to_cpu(di->i_mtime); 84 inode->i_ctime.tv_sec = le32_to_cpu(di->i_ctime); 85 inode->i_atime.tv_nsec = 0; 86 inode->i_mtime.tv_nsec = 0; 87 inode->i_ctime.tv_nsec = 0; 88 89 brelse(bh); 90 unlock_new_inode(inode); 91 return inode; 92 93 error: 94 iget_failed(inode); 95 return ERR_PTR(-EIO); 96 } 97 98 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p) 99 { 100 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) { 101 printf("Bad inode number %s:%08x\n", sb->s_id, ino); 102 return ERR_PTR(-EIO); 103 } 104 105 ino -= BFS_ROOT_INO; 106 107 *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK); 108 if (!*p) { 109 printf("Unable to read inode %s:%08x\n", sb->s_id, ino); 110 return ERR_PTR(-EIO); 111 } 112 113 return (struct bfs_inode *)(*p)->b_data + ino % BFS_INODES_PER_BLOCK; 114 } 115 116 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc) 117 { 118 struct bfs_sb_info *info = BFS_SB(inode->i_sb); 119 unsigned int ino = (u16)inode->i_ino; 120 unsigned long i_sblock; 121 struct bfs_inode *di; 122 struct buffer_head *bh; 123 int err = 0; 124 125 dprintf("ino=%08x\n", ino); 126 127 di = find_inode(inode->i_sb, ino, &bh); 128 if (IS_ERR(di)) 129 return PTR_ERR(di); 130 131 mutex_lock(&info->bfs_lock); 132 133 if (ino == BFS_ROOT_INO) 134 di->i_vtype = cpu_to_le32(BFS_VDIR); 135 else 136 di->i_vtype = cpu_to_le32(BFS_VREG); 137 138 di->i_ino = cpu_to_le16(ino); 139 di->i_mode = cpu_to_le32(inode->i_mode); 140 di->i_uid = cpu_to_le32(i_uid_read(inode)); 141 di->i_gid = cpu_to_le32(i_gid_read(inode)); 142 di->i_nlink = cpu_to_le32(inode->i_nlink); 143 di->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 144 di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 145 di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 146 i_sblock = BFS_I(inode)->i_sblock; 147 di->i_sblock = cpu_to_le32(i_sblock); 148 di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock); 149 di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1); 150 151 mark_buffer_dirty(bh); 152 if (wbc->sync_mode == WB_SYNC_ALL) { 153 sync_dirty_buffer(bh); 154 if (buffer_req(bh) && !buffer_uptodate(bh)) 155 err = -EIO; 156 } 157 brelse(bh); 158 mutex_unlock(&info->bfs_lock); 159 return err; 160 } 161 162 static void bfs_evict_inode(struct inode *inode) 163 { 164 unsigned long ino = inode->i_ino; 165 struct bfs_inode *di; 166 struct buffer_head *bh; 167 struct super_block *s = inode->i_sb; 168 struct bfs_sb_info *info = BFS_SB(s); 169 struct bfs_inode_info *bi = BFS_I(inode); 170 171 dprintf("ino=%08lx\n", ino); 172 173 truncate_inode_pages_final(&inode->i_data); 174 invalidate_inode_buffers(inode); 175 clear_inode(inode); 176 177 if (inode->i_nlink) 178 return; 179 180 di = find_inode(s, inode->i_ino, &bh); 181 if (IS_ERR(di)) 182 return; 183 184 mutex_lock(&info->bfs_lock); 185 /* clear on-disk inode */ 186 memset(di, 0, sizeof(struct bfs_inode)); 187 mark_buffer_dirty(bh); 188 brelse(bh); 189 190 if (bi->i_dsk_ino) { 191 if (bi->i_sblock) 192 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock; 193 info->si_freei++; 194 clear_bit(ino, info->si_imap); 195 bfs_dump_imap("evict_inode", s); 196 } 197 198 /* 199 * If this was the last file, make the previous block 200 * "last block of the last file" even if there is no 201 * real file there, saves us 1 gap. 202 */ 203 if (info->si_lf_eblk == bi->i_eblock) 204 info->si_lf_eblk = bi->i_sblock - 1; 205 mutex_unlock(&info->bfs_lock); 206 } 207 208 static void bfs_put_super(struct super_block *s) 209 { 210 struct bfs_sb_info *info = BFS_SB(s); 211 212 if (!info) 213 return; 214 215 mutex_destroy(&info->bfs_lock); 216 kfree(info); 217 s->s_fs_info = NULL; 218 } 219 220 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf) 221 { 222 struct super_block *s = dentry->d_sb; 223 struct bfs_sb_info *info = BFS_SB(s); 224 u64 id = huge_encode_dev(s->s_bdev->bd_dev); 225 buf->f_type = BFS_MAGIC; 226 buf->f_bsize = s->s_blocksize; 227 buf->f_blocks = info->si_blocks; 228 buf->f_bfree = buf->f_bavail = info->si_freeb; 229 buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO; 230 buf->f_ffree = info->si_freei; 231 buf->f_fsid.val[0] = (u32)id; 232 buf->f_fsid.val[1] = (u32)(id >> 32); 233 buf->f_namelen = BFS_NAMELEN; 234 return 0; 235 } 236 237 static struct kmem_cache *bfs_inode_cachep; 238 239 static struct inode *bfs_alloc_inode(struct super_block *sb) 240 { 241 struct bfs_inode_info *bi; 242 bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL); 243 if (!bi) 244 return NULL; 245 return &bi->vfs_inode; 246 } 247 248 static void bfs_i_callback(struct rcu_head *head) 249 { 250 struct inode *inode = container_of(head, struct inode, i_rcu); 251 kmem_cache_free(bfs_inode_cachep, BFS_I(inode)); 252 } 253 254 static void bfs_destroy_inode(struct inode *inode) 255 { 256 call_rcu(&inode->i_rcu, bfs_i_callback); 257 } 258 259 static void init_once(void *foo) 260 { 261 struct bfs_inode_info *bi = foo; 262 263 inode_init_once(&bi->vfs_inode); 264 } 265 266 static int __init init_inodecache(void) 267 { 268 bfs_inode_cachep = kmem_cache_create("bfs_inode_cache", 269 sizeof(struct bfs_inode_info), 270 0, (SLAB_RECLAIM_ACCOUNT| 271 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 272 init_once); 273 if (bfs_inode_cachep == NULL) 274 return -ENOMEM; 275 return 0; 276 } 277 278 static void destroy_inodecache(void) 279 { 280 /* 281 * Make sure all delayed rcu free inodes are flushed before we 282 * destroy cache. 283 */ 284 rcu_barrier(); 285 kmem_cache_destroy(bfs_inode_cachep); 286 } 287 288 static const struct super_operations bfs_sops = { 289 .alloc_inode = bfs_alloc_inode, 290 .destroy_inode = bfs_destroy_inode, 291 .write_inode = bfs_write_inode, 292 .evict_inode = bfs_evict_inode, 293 .put_super = bfs_put_super, 294 .statfs = bfs_statfs, 295 }; 296 297 void bfs_dump_imap(const char *prefix, struct super_block *s) 298 { 299 #ifdef DEBUG 300 int i; 301 char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL); 302 303 if (!tmpbuf) 304 return; 305 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) { 306 if (i > PAGE_SIZE - 100) break; 307 if (test_bit(i, BFS_SB(s)->si_imap)) 308 strcat(tmpbuf, "1"); 309 else 310 strcat(tmpbuf, "0"); 311 } 312 printf("%s: lasti=%08lx <%s>\n", 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; 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", s->s_id, le32_to_cpu(bfs_sb->s_magic)); 342 goto out1; 343 } 344 if (BFS_UNCLEAN(bfs_sb, s) && !silent) 345 printf("%s is unclean, continuing\n", s->s_id); 346 347 s->s_magic = BFS_MAGIC; 348 349 if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) || 350 le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) { 351 printf("Superblock is corrupted on %s\n", s->s_id); 352 goto out1; 353 } 354 355 info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1; 356 if (info->si_lasti == BFS_MAX_LASTI) 357 printf("WARNING: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id); 358 else if (info->si_lasti > BFS_MAX_LASTI) { 359 printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id); 360 goto out1; 361 } 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 out1; 370 } 371 s->s_root = d_make_root(inode); 372 if (!s->s_root) { 373 ret = -ENOMEM; 374 goto out1; 375 } 376 377 info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS; 378 info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - 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 on %s: %lu\n", s->s_id, info->si_blocks - 1); 386 ret = -EIO; 387 goto out2; 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 != le32_to_cpu(-1) && i_eoff > s_size) || 419 i_sblock * BFS_BSIZE > i_eoff) { 420 421 printf("Inode 0x%08x corrupted on %s\n", i, s->s_id); 422 423 brelse(bh); 424 ret = -EIO; 425 goto out2; 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 bfs_dump_imap("fill_super", s); 442 return 0; 443 444 out2: 445 dput(s->s_root); 446 s->s_root = NULL; 447 out1: 448 brelse(sbh); 449 out: 450 mutex_destroy(&info->bfs_lock); 451 kfree(info); 452 s->s_fs_info = NULL; 453 return ret; 454 } 455 456 static struct dentry *bfs_mount(struct file_system_type *fs_type, 457 int flags, const char *dev_name, void *data) 458 { 459 return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super); 460 } 461 462 static struct file_system_type bfs_fs_type = { 463 .owner = THIS_MODULE, 464 .name = "bfs", 465 .mount = bfs_mount, 466 .kill_sb = kill_block_super, 467 .fs_flags = FS_REQUIRES_DEV, 468 }; 469 MODULE_ALIAS_FS("bfs"); 470 471 static int __init init_bfs_fs(void) 472 { 473 int err = init_inodecache(); 474 if (err) 475 goto out1; 476 err = register_filesystem(&bfs_fs_type); 477 if (err) 478 goto out; 479 return 0; 480 out: 481 destroy_inodecache(); 482 out1: 483 return err; 484 } 485 486 static void __exit exit_bfs_fs(void) 487 { 488 unregister_filesystem(&bfs_fs_type); 489 destroy_inodecache(); 490 } 491 492 module_init(init_bfs_fs) 493 module_exit(exit_bfs_fs) 494