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 if (inode->i_nlink) 191 mmb_sync(&BFS_I(inode)->i_metadata_bhs); 192 mmb_invalidate(&BFS_I(inode)->i_metadata_bhs); 193 clear_inode(inode); 194 195 if (inode->i_nlink) 196 return; 197 198 di = find_inode(s, inode->i_ino, &bh); 199 if (IS_ERR(di)) 200 return; 201 202 mutex_lock(&info->bfs_lock); 203 /* clear on-disk inode */ 204 memset(di, 0, sizeof(struct bfs_inode)); 205 mark_buffer_dirty(bh); 206 brelse(bh); 207 208 if (bi->i_dsk_ino) { 209 if (bi->i_sblock) 210 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock; 211 info->si_freei++; 212 clear_bit(ino, info->si_imap); 213 bfs_dump_imap("evict_inode", s); 214 } 215 216 /* 217 * If this was the last file, make the previous block 218 * "last block of the last file" even if there is no 219 * real file there, saves us 1 gap. 220 */ 221 if (info->si_lf_eblk == bi->i_eblock) 222 info->si_lf_eblk = bi->i_sblock - 1; 223 mutex_unlock(&info->bfs_lock); 224 } 225 226 static void bfs_put_super(struct super_block *s) 227 { 228 struct bfs_sb_info *info = BFS_SB(s); 229 230 if (!info) 231 return; 232 233 mutex_destroy(&info->bfs_lock); 234 kfree(info); 235 s->s_fs_info = NULL; 236 } 237 238 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf) 239 { 240 struct super_block *s = dentry->d_sb; 241 struct bfs_sb_info *info = BFS_SB(s); 242 u64 id = huge_encode_dev(s->s_bdev->bd_dev); 243 buf->f_type = BFS_MAGIC; 244 buf->f_bsize = s->s_blocksize; 245 buf->f_blocks = info->si_blocks; 246 buf->f_bfree = buf->f_bavail = info->si_freeb; 247 buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO; 248 buf->f_ffree = info->si_freei; 249 buf->f_fsid = u64_to_fsid(id); 250 buf->f_namelen = BFS_NAMELEN; 251 return 0; 252 } 253 254 static struct kmem_cache *bfs_inode_cachep; 255 256 static struct inode *bfs_alloc_inode(struct super_block *sb) 257 { 258 struct bfs_inode_info *bi; 259 bi = alloc_inode_sb(sb, bfs_inode_cachep, GFP_KERNEL); 260 if (!bi) 261 return NULL; 262 mmb_init(&bi->i_metadata_bhs, &bi->vfs_inode.i_data); 263 264 return &bi->vfs_inode; 265 } 266 267 static void bfs_free_inode(struct inode *inode) 268 { 269 kmem_cache_free(bfs_inode_cachep, BFS_I(inode)); 270 } 271 272 static void init_once(void *foo) 273 { 274 struct bfs_inode_info *bi = foo; 275 276 inode_init_once(&bi->vfs_inode); 277 } 278 279 static int __init init_inodecache(void) 280 { 281 bfs_inode_cachep = kmem_cache_create("bfs_inode_cache", 282 sizeof(struct bfs_inode_info), 283 0, (SLAB_RECLAIM_ACCOUNT| 284 SLAB_ACCOUNT), 285 init_once); 286 if (bfs_inode_cachep == NULL) 287 return -ENOMEM; 288 return 0; 289 } 290 291 static void destroy_inodecache(void) 292 { 293 /* 294 * Make sure all delayed rcu free inodes are flushed before we 295 * destroy cache. 296 */ 297 rcu_barrier(); 298 kmem_cache_destroy(bfs_inode_cachep); 299 } 300 301 static const struct super_operations bfs_sops = { 302 .alloc_inode = bfs_alloc_inode, 303 .free_inode = bfs_free_inode, 304 .write_inode = bfs_write_inode, 305 .evict_inode = bfs_evict_inode, 306 .put_super = bfs_put_super, 307 .statfs = bfs_statfs, 308 }; 309 310 void bfs_dump_imap(const char *prefix, struct super_block *s) 311 { 312 #ifdef DEBUG 313 int i; 314 char *tmpbuf = kzalloc(PAGE_SIZE, GFP_KERNEL); 315 316 if (!tmpbuf) 317 return; 318 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) { 319 if (i > PAGE_SIZE - 100) break; 320 if (test_bit(i, BFS_SB(s)->si_imap)) 321 strcat(tmpbuf, "1"); 322 else 323 strcat(tmpbuf, "0"); 324 } 325 printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf); 326 kfree(tmpbuf); 327 #endif 328 } 329 330 static int bfs_fill_super(struct super_block *s, struct fs_context *fc) 331 { 332 struct buffer_head *bh, *sbh; 333 struct bfs_super_block *bfs_sb; 334 struct inode *inode; 335 unsigned i; 336 struct bfs_sb_info *info; 337 int ret = -EINVAL; 338 unsigned long i_sblock, i_eblock, i_eoff, s_size; 339 int silent = fc->sb_flags & SB_SILENT; 340 341 info = kzalloc_obj(*info); 342 if (!info) 343 return -ENOMEM; 344 mutex_init(&info->bfs_lock); 345 s->s_fs_info = info; 346 s->s_time_min = 0; 347 s->s_time_max = U32_MAX; 348 349 if (!sb_set_blocksize(s, BFS_BSIZE)) 350 goto out; 351 352 sbh = sb_bread(s, 0); 353 if (!sbh) 354 goto out; 355 bfs_sb = (struct bfs_super_block *)sbh->b_data; 356 if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) { 357 if (!silent) 358 printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id, le32_to_cpu(bfs_sb->s_magic)); 359 goto out1; 360 } 361 if (BFS_UNCLEAN(bfs_sb, s) && !silent) 362 printf("%s is unclean, continuing\n", s->s_id); 363 364 s->s_magic = BFS_MAGIC; 365 366 if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) || 367 le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) { 368 printf("Superblock is corrupted on %s\n", s->s_id); 369 goto out1; 370 } 371 372 info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1; 373 if (info->si_lasti == BFS_MAX_LASTI) 374 printf("NOTE: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id); 375 else if (info->si_lasti > BFS_MAX_LASTI) { 376 printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id); 377 goto out1; 378 } 379 for (i = 0; i < BFS_ROOT_INO; i++) 380 set_bit(i, info->si_imap); 381 382 s->s_op = &bfs_sops; 383 inode = bfs_iget(s, BFS_ROOT_INO); 384 if (IS_ERR(inode)) { 385 ret = PTR_ERR(inode); 386 goto out1; 387 } 388 s->s_root = d_make_root(inode); 389 if (!s->s_root) { 390 ret = -ENOMEM; 391 goto out1; 392 } 393 394 info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS; 395 info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS; 396 info->si_freei = 0; 397 info->si_lf_eblk = 0; 398 399 /* can we read the last block? */ 400 bh = sb_bread(s, info->si_blocks - 1); 401 if (!bh) { 402 printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1); 403 ret = -EIO; 404 goto out2; 405 } 406 brelse(bh); 407 408 bh = NULL; 409 for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) { 410 struct bfs_inode *di; 411 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1; 412 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK; 413 unsigned long eblock; 414 415 if (!off) { 416 brelse(bh); 417 bh = sb_bread(s, block); 418 } 419 420 if (!bh) 421 continue; 422 423 di = (struct bfs_inode *)bh->b_data + off; 424 425 /* test if filesystem is not corrupted */ 426 427 i_eoff = le32_to_cpu(di->i_eoffset); 428 i_sblock = le32_to_cpu(di->i_sblock); 429 i_eblock = le32_to_cpu(di->i_eblock); 430 s_size = le32_to_cpu(bfs_sb->s_end); 431 432 if (i_sblock > info->si_blocks || 433 i_eblock > info->si_blocks || 434 i_sblock > i_eblock || 435 (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) || 436 i_sblock * BFS_BSIZE > i_eoff) { 437 438 printf("Inode 0x%08x corrupted on %s\n", i, s->s_id); 439 440 brelse(bh); 441 ret = -EIO; 442 goto out2; 443 } 444 445 if (!di->i_ino) { 446 info->si_freei++; 447 continue; 448 } 449 set_bit(i, info->si_imap); 450 info->si_freeb -= BFS_FILEBLOCKS(di); 451 452 eblock = le32_to_cpu(di->i_eblock); 453 if (eblock > info->si_lf_eblk) 454 info->si_lf_eblk = eblock; 455 } 456 brelse(bh); 457 brelse(sbh); 458 bfs_dump_imap("fill_super", s); 459 return 0; 460 461 out2: 462 dput(s->s_root); 463 s->s_root = NULL; 464 out1: 465 brelse(sbh); 466 out: 467 mutex_destroy(&info->bfs_lock); 468 kfree(info); 469 s->s_fs_info = NULL; 470 return ret; 471 } 472 473 static int bfs_get_tree(struct fs_context *fc) 474 { 475 return get_tree_bdev(fc, bfs_fill_super); 476 } 477 478 static const struct fs_context_operations bfs_context_ops = { 479 .get_tree = bfs_get_tree, 480 }; 481 482 static int bfs_init_fs_context(struct fs_context *fc) 483 { 484 fc->ops = &bfs_context_ops; 485 486 return 0; 487 } 488 489 static struct file_system_type bfs_fs_type = { 490 .owner = THIS_MODULE, 491 .name = "bfs", 492 .init_fs_context = bfs_init_fs_context, 493 .kill_sb = kill_block_super, 494 .fs_flags = FS_REQUIRES_DEV, 495 }; 496 MODULE_ALIAS_FS("bfs"); 497 498 static int __init init_bfs_fs(void) 499 { 500 int err = init_inodecache(); 501 if (err) 502 goto out1; 503 err = register_filesystem(&bfs_fs_type); 504 if (err) 505 goto out; 506 return 0; 507 out: 508 destroy_inodecache(); 509 out1: 510 return err; 511 } 512 513 static void __exit exit_bfs_fs(void) 514 { 515 unregister_filesystem(&bfs_fs_type); 516 destroy_inodecache(); 517 } 518 519 module_init(init_bfs_fs) 520 module_exit(exit_bfs_fs) 521