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 "bfs.h" 21 22 MODULE_AUTHOR("Tigran Aivazian <aivazian.tigran@gmail.com>"); 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 struct inode *bfs_iget(struct super_block *sb, unsigned long ino) 35 { 36 struct bfs_inode *di; 37 struct inode *inode; 38 struct buffer_head *bh; 39 int block, off; 40 41 inode = iget_locked(sb, ino); 42 if (!inode) 43 return ERR_PTR(-ENOMEM); 44 if (!(inode->i_state & I_NEW)) 45 return inode; 46 47 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) { 48 printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino); 49 goto error; 50 } 51 52 block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1; 53 bh = sb_bread(inode->i_sb, block); 54 if (!bh) { 55 printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id, 56 ino); 57 goto error; 58 } 59 60 off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK; 61 di = (struct bfs_inode *)bh->b_data + off; 62 63 inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode); 64 if (le32_to_cpu(di->i_vtype) == BFS_VDIR) { 65 inode->i_mode |= S_IFDIR; 66 inode->i_op = &bfs_dir_inops; 67 inode->i_fop = &bfs_dir_operations; 68 } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) { 69 inode->i_mode |= S_IFREG; 70 inode->i_op = &bfs_file_inops; 71 inode->i_fop = &bfs_file_operations; 72 inode->i_mapping->a_ops = &bfs_aops; 73 } 74 75 BFS_I(inode)->i_sblock = le32_to_cpu(di->i_sblock); 76 BFS_I(inode)->i_eblock = le32_to_cpu(di->i_eblock); 77 BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino); 78 i_uid_write(inode, le32_to_cpu(di->i_uid)); 79 i_gid_write(inode, le32_to_cpu(di->i_gid)); 80 set_nlink(inode, le32_to_cpu(di->i_nlink)); 81 inode->i_size = BFS_FILESIZE(di); 82 inode->i_blocks = BFS_FILEBLOCKS(di); 83 inode->i_atime.tv_sec = le32_to_cpu(di->i_atime); 84 inode->i_mtime.tv_sec = le32_to_cpu(di->i_mtime); 85 inode->i_ctime.tv_sec = le32_to_cpu(di->i_ctime); 86 inode->i_atime.tv_nsec = 0; 87 inode->i_mtime.tv_nsec = 0; 88 inode->i_ctime.tv_nsec = 0; 89 90 brelse(bh); 91 unlock_new_inode(inode); 92 return inode; 93 94 error: 95 iget_failed(inode); 96 return ERR_PTR(-EIO); 97 } 98 99 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p) 100 { 101 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) { 102 printf("Bad inode number %s:%08x\n", sb->s_id, ino); 103 return ERR_PTR(-EIO); 104 } 105 106 ino -= BFS_ROOT_INO; 107 108 *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK); 109 if (!*p) { 110 printf("Unable to read inode %s:%08x\n", sb->s_id, ino); 111 return ERR_PTR(-EIO); 112 } 113 114 return (struct bfs_inode *)(*p)->b_data + ino % BFS_INODES_PER_BLOCK; 115 } 116 117 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc) 118 { 119 struct bfs_sb_info *info = BFS_SB(inode->i_sb); 120 unsigned int ino = (u16)inode->i_ino; 121 unsigned long i_sblock; 122 struct bfs_inode *di; 123 struct buffer_head *bh; 124 int err = 0; 125 126 dprintf("ino=%08x\n", ino); 127 128 di = find_inode(inode->i_sb, ino, &bh); 129 if (IS_ERR(di)) 130 return PTR_ERR(di); 131 132 mutex_lock(&info->bfs_lock); 133 134 if (ino == BFS_ROOT_INO) 135 di->i_vtype = cpu_to_le32(BFS_VDIR); 136 else 137 di->i_vtype = cpu_to_le32(BFS_VREG); 138 139 di->i_ino = cpu_to_le16(ino); 140 di->i_mode = cpu_to_le32(inode->i_mode); 141 di->i_uid = cpu_to_le32(i_uid_read(inode)); 142 di->i_gid = cpu_to_le32(i_gid_read(inode)); 143 di->i_nlink = cpu_to_le32(inode->i_nlink); 144 di->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 145 di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 146 di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 147 i_sblock = BFS_I(inode)->i_sblock; 148 di->i_sblock = cpu_to_le32(i_sblock); 149 di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock); 150 di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1); 151 152 mark_buffer_dirty(bh); 153 if (wbc->sync_mode == WB_SYNC_ALL) { 154 sync_dirty_buffer(bh); 155 if (buffer_req(bh) && !buffer_uptodate(bh)) 156 err = -EIO; 157 } 158 brelse(bh); 159 mutex_unlock(&info->bfs_lock); 160 return err; 161 } 162 163 static void bfs_evict_inode(struct inode *inode) 164 { 165 unsigned long ino = inode->i_ino; 166 struct bfs_inode *di; 167 struct buffer_head *bh; 168 struct super_block *s = inode->i_sb; 169 struct bfs_sb_info *info = BFS_SB(s); 170 struct bfs_inode_info *bi = BFS_I(inode); 171 172 dprintf("ino=%08lx\n", ino); 173 174 truncate_inode_pages_final(&inode->i_data); 175 invalidate_inode_buffers(inode); 176 clear_inode(inode); 177 178 if (inode->i_nlink) 179 return; 180 181 di = find_inode(s, inode->i_ino, &bh); 182 if (IS_ERR(di)) 183 return; 184 185 mutex_lock(&info->bfs_lock); 186 /* clear on-disk inode */ 187 memset(di, 0, sizeof(struct bfs_inode)); 188 mark_buffer_dirty(bh); 189 brelse(bh); 190 191 if (bi->i_dsk_ino) { 192 if (bi->i_sblock) 193 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock; 194 info->si_freei++; 195 clear_bit(ino, info->si_imap); 196 bfs_dump_imap("evict_inode", s); 197 } 198 199 /* 200 * If this was the last file, make the previous block 201 * "last block of the last file" even if there is no 202 * real file there, saves us 1 gap. 203 */ 204 if (info->si_lf_eblk == bi->i_eblock) 205 info->si_lf_eblk = bi->i_sblock - 1; 206 mutex_unlock(&info->bfs_lock); 207 } 208 209 static void bfs_put_super(struct super_block *s) 210 { 211 struct bfs_sb_info *info = BFS_SB(s); 212 213 if (!info) 214 return; 215 216 mutex_destroy(&info->bfs_lock); 217 kfree(info); 218 s->s_fs_info = NULL; 219 } 220 221 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf) 222 { 223 struct super_block *s = dentry->d_sb; 224 struct bfs_sb_info *info = BFS_SB(s); 225 u64 id = huge_encode_dev(s->s_bdev->bd_dev); 226 buf->f_type = BFS_MAGIC; 227 buf->f_bsize = s->s_blocksize; 228 buf->f_blocks = info->si_blocks; 229 buf->f_bfree = buf->f_bavail = info->si_freeb; 230 buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO; 231 buf->f_ffree = info->si_freei; 232 buf->f_fsid = u64_to_fsid(id); 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 = alloc_inode_sb(sb, bfs_inode_cachep, GFP_KERNEL); 243 if (!bi) 244 return NULL; 245 return &bi->vfs_inode; 246 } 247 248 static void bfs_free_inode(struct inode *inode) 249 { 250 kmem_cache_free(bfs_inode_cachep, BFS_I(inode)); 251 } 252 253 static void init_once(void *foo) 254 { 255 struct bfs_inode_info *bi = foo; 256 257 inode_init_once(&bi->vfs_inode); 258 } 259 260 static int __init init_inodecache(void) 261 { 262 bfs_inode_cachep = kmem_cache_create("bfs_inode_cache", 263 sizeof(struct bfs_inode_info), 264 0, (SLAB_RECLAIM_ACCOUNT| 265 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 266 init_once); 267 if (bfs_inode_cachep == NULL) 268 return -ENOMEM; 269 return 0; 270 } 271 272 static void destroy_inodecache(void) 273 { 274 /* 275 * Make sure all delayed rcu free inodes are flushed before we 276 * destroy cache. 277 */ 278 rcu_barrier(); 279 kmem_cache_destroy(bfs_inode_cachep); 280 } 281 282 static const struct super_operations bfs_sops = { 283 .alloc_inode = bfs_alloc_inode, 284 .free_inode = bfs_free_inode, 285 .write_inode = bfs_write_inode, 286 .evict_inode = bfs_evict_inode, 287 .put_super = bfs_put_super, 288 .statfs = bfs_statfs, 289 }; 290 291 void bfs_dump_imap(const char *prefix, struct super_block *s) 292 { 293 #ifdef DEBUG 294 int i; 295 char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL); 296 297 if (!tmpbuf) 298 return; 299 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) { 300 if (i > PAGE_SIZE - 100) break; 301 if (test_bit(i, BFS_SB(s)->si_imap)) 302 strcat(tmpbuf, "1"); 303 else 304 strcat(tmpbuf, "0"); 305 } 306 printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf); 307 free_page((unsigned long)tmpbuf); 308 #endif 309 } 310 311 static int bfs_fill_super(struct super_block *s, void *data, int silent) 312 { 313 struct buffer_head *bh, *sbh; 314 struct bfs_super_block *bfs_sb; 315 struct inode *inode; 316 unsigned i; 317 struct bfs_sb_info *info; 318 int ret = -EINVAL; 319 unsigned long i_sblock, i_eblock, i_eoff, s_size; 320 321 info = kzalloc(sizeof(*info), GFP_KERNEL); 322 if (!info) 323 return -ENOMEM; 324 mutex_init(&info->bfs_lock); 325 s->s_fs_info = info; 326 s->s_time_min = 0; 327 s->s_time_max = U32_MAX; 328 329 sb_set_blocksize(s, BFS_BSIZE); 330 331 sbh = sb_bread(s, 0); 332 if (!sbh) 333 goto out; 334 bfs_sb = (struct bfs_super_block *)sbh->b_data; 335 if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) { 336 if (!silent) 337 printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id, le32_to_cpu(bfs_sb->s_magic)); 338 goto out1; 339 } 340 if (BFS_UNCLEAN(bfs_sb, s) && !silent) 341 printf("%s is unclean, continuing\n", s->s_id); 342 343 s->s_magic = BFS_MAGIC; 344 345 if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) || 346 le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) { 347 printf("Superblock is corrupted on %s\n", s->s_id); 348 goto out1; 349 } 350 351 info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1; 352 if (info->si_lasti == BFS_MAX_LASTI) 353 printf("NOTE: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id); 354 else if (info->si_lasti > BFS_MAX_LASTI) { 355 printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id); 356 goto out1; 357 } 358 for (i = 0; i < BFS_ROOT_INO; i++) 359 set_bit(i, info->si_imap); 360 361 s->s_op = &bfs_sops; 362 inode = bfs_iget(s, BFS_ROOT_INO); 363 if (IS_ERR(inode)) { 364 ret = PTR_ERR(inode); 365 goto out1; 366 } 367 s->s_root = d_make_root(inode); 368 if (!s->s_root) { 369 ret = -ENOMEM; 370 goto out1; 371 } 372 373 info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS; 374 info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS; 375 info->si_freei = 0; 376 info->si_lf_eblk = 0; 377 378 /* can we read the last block? */ 379 bh = sb_bread(s, info->si_blocks - 1); 380 if (!bh) { 381 printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1); 382 ret = -EIO; 383 goto out2; 384 } 385 brelse(bh); 386 387 bh = NULL; 388 for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) { 389 struct bfs_inode *di; 390 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1; 391 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK; 392 unsigned long eblock; 393 394 if (!off) { 395 brelse(bh); 396 bh = sb_bread(s, block); 397 } 398 399 if (!bh) 400 continue; 401 402 di = (struct bfs_inode *)bh->b_data + off; 403 404 /* test if filesystem is not corrupted */ 405 406 i_eoff = le32_to_cpu(di->i_eoffset); 407 i_sblock = le32_to_cpu(di->i_sblock); 408 i_eblock = le32_to_cpu(di->i_eblock); 409 s_size = le32_to_cpu(bfs_sb->s_end); 410 411 if (i_sblock > info->si_blocks || 412 i_eblock > info->si_blocks || 413 i_sblock > i_eblock || 414 (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) || 415 i_sblock * BFS_BSIZE > i_eoff) { 416 417 printf("Inode 0x%08x corrupted on %s\n", i, s->s_id); 418 419 brelse(bh); 420 ret = -EIO; 421 goto out2; 422 } 423 424 if (!di->i_ino) { 425 info->si_freei++; 426 continue; 427 } 428 set_bit(i, info->si_imap); 429 info->si_freeb -= BFS_FILEBLOCKS(di); 430 431 eblock = le32_to_cpu(di->i_eblock); 432 if (eblock > info->si_lf_eblk) 433 info->si_lf_eblk = eblock; 434 } 435 brelse(bh); 436 brelse(sbh); 437 bfs_dump_imap("fill_super", s); 438 return 0; 439 440 out2: 441 dput(s->s_root); 442 s->s_root = NULL; 443 out1: 444 brelse(sbh); 445 out: 446 mutex_destroy(&info->bfs_lock); 447 kfree(info); 448 s->s_fs_info = NULL; 449 return ret; 450 } 451 452 static struct dentry *bfs_mount(struct file_system_type *fs_type, 453 int flags, const char *dev_name, void *data) 454 { 455 return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super); 456 } 457 458 static struct file_system_type bfs_fs_type = { 459 .owner = THIS_MODULE, 460 .name = "bfs", 461 .mount = bfs_mount, 462 .kill_sb = kill_block_super, 463 .fs_flags = FS_REQUIRES_DEV, 464 }; 465 MODULE_ALIAS_FS("bfs"); 466 467 static int __init init_bfs_fs(void) 468 { 469 int err = init_inodecache(); 470 if (err) 471 goto out1; 472 err = register_filesystem(&bfs_fs_type); 473 if (err) 474 goto out; 475 return 0; 476 out: 477 destroy_inodecache(); 478 out1: 479 return err; 480 } 481 482 static void __exit exit_bfs_fs(void) 483 { 484 unregister_filesystem(&bfs_fs_type); 485 destroy_inodecache(); 486 } 487 488 module_init(init_bfs_fs) 489 module_exit(exit_bfs_fs) 490