1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * fs/bfs/inode.c 4 * BFS superblock and inode operations. 5 * Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com> 6 * From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds. 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 <linux/uio.h> 19 #include <linux/uaccess.h> 20 #include <linux/fs_context.h> 21 #include "bfs.h" 22 23 MODULE_AUTHOR("Tigran Aivazian <aivazian.tigran@gmail.com>"); 24 MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux"); 25 MODULE_LICENSE("GPL"); 26 27 #undef DEBUG 28 29 #ifdef DEBUG 30 #define dprintf(x...) printf(x) 31 #else 32 #define dprintf(x...) 33 #endif 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 (!inode) 44 return ERR_PTR(-ENOMEM); 45 if (!(inode_state_read_once(inode) & 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 /* 65 * https://martin.hinner.info/fs/bfs/bfs-structure.html explains that 66 * BFS in SCO UnixWare environment used only lower 9 bits of di->i_mode 67 * value. This means that, although bfs_write_inode() saves whole 68 * inode->i_mode bits (which include S_IFMT bits and S_IS{UID,GID,VTX} 69 * bits), middle 7 bits of di->i_mode value can be garbage when these 70 * bits were not saved by bfs_write_inode(). 71 * Since we can't tell whether middle 7 bits are garbage, use only 72 * lower 12 bits (i.e. tolerate S_IS{UID,GID,VTX} bits possibly being 73 * garbage) and reconstruct S_IFMT bits for Linux environment from 74 * di->i_vtype value. 75 */ 76 inode->i_mode = 0x00000FFF & le32_to_cpu(di->i_mode); 77 if (le32_to_cpu(di->i_vtype) == BFS_VDIR) { 78 inode->i_mode |= S_IFDIR; 79 inode->i_op = &bfs_dir_inops; 80 inode->i_fop = &bfs_dir_operations; 81 } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) { 82 inode->i_mode |= S_IFREG; 83 inode->i_op = &bfs_file_inops; 84 inode->i_fop = &bfs_file_operations; 85 inode->i_mapping->a_ops = &bfs_aops; 86 } else { 87 brelse(bh); 88 printf("Unknown vtype=%u %s:%08lx\n", 89 le32_to_cpu(di->i_vtype), inode->i_sb->s_id, ino); 90 goto error; 91 } 92 93 BFS_I(inode)->i_sblock = le32_to_cpu(di->i_sblock); 94 BFS_I(inode)->i_eblock = le32_to_cpu(di->i_eblock); 95 BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino); 96 i_uid_write(inode, le32_to_cpu(di->i_uid)); 97 i_gid_write(inode, le32_to_cpu(di->i_gid)); 98 set_nlink(inode, le32_to_cpu(di->i_nlink)); 99 inode->i_size = BFS_FILESIZE(di); 100 inode->i_blocks = BFS_FILEBLOCKS(di); 101 inode_set_atime(inode, le32_to_cpu(di->i_atime), 0); 102 inode_set_mtime(inode, le32_to_cpu(di->i_mtime), 0); 103 inode_set_ctime(inode, le32_to_cpu(di->i_ctime), 0); 104 105 brelse(bh); 106 unlock_new_inode(inode); 107 return inode; 108 109 error: 110 iget_failed(inode); 111 return ERR_PTR(-EIO); 112 } 113 114 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p) 115 { 116 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) { 117 printf("Bad inode number %s:%08x\n", sb->s_id, ino); 118 return ERR_PTR(-EIO); 119 } 120 121 ino -= BFS_ROOT_INO; 122 123 *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK); 124 if (!*p) { 125 printf("Unable to read inode %s:%08x\n", sb->s_id, ino); 126 return ERR_PTR(-EIO); 127 } 128 129 return (struct bfs_inode *)(*p)->b_data + ino % BFS_INODES_PER_BLOCK; 130 } 131 132 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc) 133 { 134 struct bfs_sb_info *info = BFS_SB(inode->i_sb); 135 unsigned int ino = (u16)inode->i_ino; 136 unsigned long i_sblock; 137 struct bfs_inode *di; 138 struct buffer_head *bh; 139 int err = 0; 140 141 dprintf("ino=%08x\n", ino); 142 143 di = find_inode(inode->i_sb, ino, &bh); 144 if (IS_ERR(di)) 145 return PTR_ERR(di); 146 147 mutex_lock(&info->bfs_lock); 148 149 if (ino == BFS_ROOT_INO) 150 di->i_vtype = cpu_to_le32(BFS_VDIR); 151 else 152 di->i_vtype = cpu_to_le32(BFS_VREG); 153 154 di->i_ino = cpu_to_le16(ino); 155 di->i_mode = cpu_to_le32(inode->i_mode); 156 di->i_uid = cpu_to_le32(i_uid_read(inode)); 157 di->i_gid = cpu_to_le32(i_gid_read(inode)); 158 di->i_nlink = cpu_to_le32(inode->i_nlink); 159 di->i_atime = cpu_to_le32(inode_get_atime_sec(inode)); 160 di->i_mtime = cpu_to_le32(inode_get_mtime_sec(inode)); 161 di->i_ctime = cpu_to_le32(inode_get_ctime_sec(inode)); 162 i_sblock = BFS_I(inode)->i_sblock; 163 di->i_sblock = cpu_to_le32(i_sblock); 164 di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock); 165 di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1); 166 167 mark_buffer_dirty(bh); 168 if (wbc->sync_mode == WB_SYNC_ALL) { 169 sync_dirty_buffer(bh); 170 if (buffer_req(bh) && !buffer_uptodate(bh)) 171 err = -EIO; 172 } 173 brelse(bh); 174 mutex_unlock(&info->bfs_lock); 175 return err; 176 } 177 178 static void bfs_evict_inode(struct inode *inode) 179 { 180 unsigned long ino = inode->i_ino; 181 struct bfs_inode *di; 182 struct buffer_head *bh; 183 struct super_block *s = inode->i_sb; 184 struct bfs_sb_info *info = BFS_SB(s); 185 struct bfs_inode_info *bi = BFS_I(inode); 186 187 dprintf("ino=%08lx\n", ino); 188 189 truncate_inode_pages_final(&inode->i_data); 190 invalidate_inode_buffers(inode); 191 clear_inode(inode); 192 193 if (inode->i_nlink) 194 return; 195 196 di = find_inode(s, inode->i_ino, &bh); 197 if (IS_ERR(di)) 198 return; 199 200 mutex_lock(&info->bfs_lock); 201 /* clear on-disk inode */ 202 memset(di, 0, sizeof(struct bfs_inode)); 203 mark_buffer_dirty(bh); 204 brelse(bh); 205 206 if (bi->i_dsk_ino) { 207 if (bi->i_sblock) 208 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock; 209 info->si_freei++; 210 clear_bit(ino, info->si_imap); 211 bfs_dump_imap("evict_inode", s); 212 } 213 214 /* 215 * If this was the last file, make the previous block 216 * "last block of the last file" even if there is no 217 * real file there, saves us 1 gap. 218 */ 219 if (info->si_lf_eblk == bi->i_eblock) 220 info->si_lf_eblk = bi->i_sblock - 1; 221 mutex_unlock(&info->bfs_lock); 222 } 223 224 static void bfs_put_super(struct super_block *s) 225 { 226 struct bfs_sb_info *info = BFS_SB(s); 227 228 if (!info) 229 return; 230 231 mutex_destroy(&info->bfs_lock); 232 kfree(info); 233 s->s_fs_info = NULL; 234 } 235 236 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf) 237 { 238 struct super_block *s = dentry->d_sb; 239 struct bfs_sb_info *info = BFS_SB(s); 240 u64 id = huge_encode_dev(s->s_bdev->bd_dev); 241 buf->f_type = BFS_MAGIC; 242 buf->f_bsize = s->s_blocksize; 243 buf->f_blocks = info->si_blocks; 244 buf->f_bfree = buf->f_bavail = info->si_freeb; 245 buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO; 246 buf->f_ffree = info->si_freei; 247 buf->f_fsid = u64_to_fsid(id); 248 buf->f_namelen = BFS_NAMELEN; 249 return 0; 250 } 251 252 static struct kmem_cache *bfs_inode_cachep; 253 254 static struct inode *bfs_alloc_inode(struct super_block *sb) 255 { 256 struct bfs_inode_info *bi; 257 bi = alloc_inode_sb(sb, bfs_inode_cachep, GFP_KERNEL); 258 if (!bi) 259 return NULL; 260 return &bi->vfs_inode; 261 } 262 263 static void bfs_free_inode(struct inode *inode) 264 { 265 kmem_cache_free(bfs_inode_cachep, BFS_I(inode)); 266 } 267 268 static void init_once(void *foo) 269 { 270 struct bfs_inode_info *bi = foo; 271 272 inode_init_once(&bi->vfs_inode); 273 } 274 275 static int __init init_inodecache(void) 276 { 277 bfs_inode_cachep = kmem_cache_create("bfs_inode_cache", 278 sizeof(struct bfs_inode_info), 279 0, (SLAB_RECLAIM_ACCOUNT| 280 SLAB_ACCOUNT), 281 init_once); 282 if (bfs_inode_cachep == NULL) 283 return -ENOMEM; 284 return 0; 285 } 286 287 static void destroy_inodecache(void) 288 { 289 /* 290 * Make sure all delayed rcu free inodes are flushed before we 291 * destroy cache. 292 */ 293 rcu_barrier(); 294 kmem_cache_destroy(bfs_inode_cachep); 295 } 296 297 static const struct super_operations bfs_sops = { 298 .alloc_inode = bfs_alloc_inode, 299 .free_inode = bfs_free_inode, 300 .write_inode = bfs_write_inode, 301 .evict_inode = bfs_evict_inode, 302 .put_super = bfs_put_super, 303 .statfs = bfs_statfs, 304 }; 305 306 void bfs_dump_imap(const char *prefix, struct super_block *s) 307 { 308 #ifdef DEBUG 309 int i; 310 char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL); 311 312 if (!tmpbuf) 313 return; 314 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) { 315 if (i > PAGE_SIZE - 100) break; 316 if (test_bit(i, BFS_SB(s)->si_imap)) 317 strcat(tmpbuf, "1"); 318 else 319 strcat(tmpbuf, "0"); 320 } 321 printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf); 322 free_page((unsigned long)tmpbuf); 323 #endif 324 } 325 326 static int bfs_fill_super(struct super_block *s, struct fs_context *fc) 327 { 328 struct buffer_head *bh, *sbh; 329 struct bfs_super_block *bfs_sb; 330 struct inode *inode; 331 unsigned i; 332 struct bfs_sb_info *info; 333 int ret = -EINVAL; 334 unsigned long i_sblock, i_eblock, i_eoff, s_size; 335 int silent = fc->sb_flags & SB_SILENT; 336 337 info = kzalloc(sizeof(*info), GFP_KERNEL); 338 if (!info) 339 return -ENOMEM; 340 mutex_init(&info->bfs_lock); 341 s->s_fs_info = info; 342 s->s_time_min = 0; 343 s->s_time_max = U32_MAX; 344 345 sb_set_blocksize(s, BFS_BSIZE); 346 347 sbh = sb_bread(s, 0); 348 if (!sbh) 349 goto out; 350 bfs_sb = (struct bfs_super_block *)sbh->b_data; 351 if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) { 352 if (!silent) 353 printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id, le32_to_cpu(bfs_sb->s_magic)); 354 goto out1; 355 } 356 if (BFS_UNCLEAN(bfs_sb, s) && !silent) 357 printf("%s is unclean, continuing\n", s->s_id); 358 359 s->s_magic = BFS_MAGIC; 360 361 if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) || 362 le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) { 363 printf("Superblock is corrupted on %s\n", s->s_id); 364 goto out1; 365 } 366 367 info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1; 368 if (info->si_lasti == BFS_MAX_LASTI) 369 printf("NOTE: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id); 370 else if (info->si_lasti > BFS_MAX_LASTI) { 371 printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id); 372 goto out1; 373 } 374 for (i = 0; i < BFS_ROOT_INO; i++) 375 set_bit(i, info->si_imap); 376 377 s->s_op = &bfs_sops; 378 inode = bfs_iget(s, BFS_ROOT_INO); 379 if (IS_ERR(inode)) { 380 ret = PTR_ERR(inode); 381 goto out1; 382 } 383 s->s_root = d_make_root(inode); 384 if (!s->s_root) { 385 ret = -ENOMEM; 386 goto out1; 387 } 388 389 info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS; 390 info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS; 391 info->si_freei = 0; 392 info->si_lf_eblk = 0; 393 394 /* can we read the last block? */ 395 bh = sb_bread(s, info->si_blocks - 1); 396 if (!bh) { 397 printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1); 398 ret = -EIO; 399 goto out2; 400 } 401 brelse(bh); 402 403 bh = NULL; 404 for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) { 405 struct bfs_inode *di; 406 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1; 407 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK; 408 unsigned long eblock; 409 410 if (!off) { 411 brelse(bh); 412 bh = sb_bread(s, block); 413 } 414 415 if (!bh) 416 continue; 417 418 di = (struct bfs_inode *)bh->b_data + off; 419 420 /* test if filesystem is not corrupted */ 421 422 i_eoff = le32_to_cpu(di->i_eoffset); 423 i_sblock = le32_to_cpu(di->i_sblock); 424 i_eblock = le32_to_cpu(di->i_eblock); 425 s_size = le32_to_cpu(bfs_sb->s_end); 426 427 if (i_sblock > info->si_blocks || 428 i_eblock > info->si_blocks || 429 i_sblock > i_eblock || 430 (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) || 431 i_sblock * BFS_BSIZE > i_eoff) { 432 433 printf("Inode 0x%08x corrupted on %s\n", i, s->s_id); 434 435 brelse(bh); 436 ret = -EIO; 437 goto out2; 438 } 439 440 if (!di->i_ino) { 441 info->si_freei++; 442 continue; 443 } 444 set_bit(i, info->si_imap); 445 info->si_freeb -= BFS_FILEBLOCKS(di); 446 447 eblock = le32_to_cpu(di->i_eblock); 448 if (eblock > info->si_lf_eblk) 449 info->si_lf_eblk = eblock; 450 } 451 brelse(bh); 452 brelse(sbh); 453 bfs_dump_imap("fill_super", s); 454 return 0; 455 456 out2: 457 dput(s->s_root); 458 s->s_root = NULL; 459 out1: 460 brelse(sbh); 461 out: 462 mutex_destroy(&info->bfs_lock); 463 kfree(info); 464 s->s_fs_info = NULL; 465 return ret; 466 } 467 468 static int bfs_get_tree(struct fs_context *fc) 469 { 470 return get_tree_bdev(fc, bfs_fill_super); 471 } 472 473 static const struct fs_context_operations bfs_context_ops = { 474 .get_tree = bfs_get_tree, 475 }; 476 477 static int bfs_init_fs_context(struct fs_context *fc) 478 { 479 fc->ops = &bfs_context_ops; 480 481 return 0; 482 } 483 484 static struct file_system_type bfs_fs_type = { 485 .owner = THIS_MODULE, 486 .name = "bfs", 487 .init_fs_context = bfs_init_fs_context, 488 .kill_sb = kill_block_super, 489 .fs_flags = FS_REQUIRES_DEV, 490 }; 491 MODULE_ALIAS_FS("bfs"); 492 493 static int __init init_bfs_fs(void) 494 { 495 int err = init_inodecache(); 496 if (err) 497 goto out1; 498 err = register_filesystem(&bfs_fs_type); 499 if (err) 500 goto out; 501 return 0; 502 out: 503 destroy_inodecache(); 504 out1: 505 return err; 506 } 507 508 static void __exit exit_bfs_fs(void) 509 { 510 unregister_filesystem(&bfs_fs_type); 511 destroy_inodecache(); 512 } 513 514 module_init(init_bfs_fs) 515 module_exit(exit_bfs_fs) 516