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