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_set_atime(inode, le32_to_cpu(di->i_atime), 0); 84 inode_set_mtime(inode, le32_to_cpu(di->i_mtime), 0); 85 inode_set_ctime(inode, le32_to_cpu(di->i_ctime), 0); 86 87 brelse(bh); 88 unlock_new_inode(inode); 89 return inode; 90 91 error: 92 iget_failed(inode); 93 return ERR_PTR(-EIO); 94 } 95 96 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p) 97 { 98 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) { 99 printf("Bad inode number %s:%08x\n", sb->s_id, ino); 100 return ERR_PTR(-EIO); 101 } 102 103 ino -= BFS_ROOT_INO; 104 105 *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK); 106 if (!*p) { 107 printf("Unable to read inode %s:%08x\n", sb->s_id, ino); 108 return ERR_PTR(-EIO); 109 } 110 111 return (struct bfs_inode *)(*p)->b_data + ino % BFS_INODES_PER_BLOCK; 112 } 113 114 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc) 115 { 116 struct bfs_sb_info *info = BFS_SB(inode->i_sb); 117 unsigned int ino = (u16)inode->i_ino; 118 unsigned long i_sblock; 119 struct bfs_inode *di; 120 struct buffer_head *bh; 121 int err = 0; 122 123 dprintf("ino=%08x\n", ino); 124 125 di = find_inode(inode->i_sb, ino, &bh); 126 if (IS_ERR(di)) 127 return PTR_ERR(di); 128 129 mutex_lock(&info->bfs_lock); 130 131 if (ino == BFS_ROOT_INO) 132 di->i_vtype = cpu_to_le32(BFS_VDIR); 133 else 134 di->i_vtype = cpu_to_le32(BFS_VREG); 135 136 di->i_ino = cpu_to_le16(ino); 137 di->i_mode = cpu_to_le32(inode->i_mode); 138 di->i_uid = cpu_to_le32(i_uid_read(inode)); 139 di->i_gid = cpu_to_le32(i_gid_read(inode)); 140 di->i_nlink = cpu_to_le32(inode->i_nlink); 141 di->i_atime = cpu_to_le32(inode_get_atime_sec(inode)); 142 di->i_mtime = cpu_to_le32(inode_get_mtime_sec(inode)); 143 di->i_ctime = cpu_to_le32(inode_get_ctime_sec(inode)); 144 i_sblock = BFS_I(inode)->i_sblock; 145 di->i_sblock = cpu_to_le32(i_sblock); 146 di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock); 147 di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1); 148 149 mark_buffer_dirty(bh); 150 if (wbc->sync_mode == WB_SYNC_ALL) { 151 sync_dirty_buffer(bh); 152 if (buffer_req(bh) && !buffer_uptodate(bh)) 153 err = -EIO; 154 } 155 brelse(bh); 156 mutex_unlock(&info->bfs_lock); 157 return err; 158 } 159 160 static void bfs_evict_inode(struct inode *inode) 161 { 162 unsigned long ino = inode->i_ino; 163 struct bfs_inode *di; 164 struct buffer_head *bh; 165 struct super_block *s = inode->i_sb; 166 struct bfs_sb_info *info = BFS_SB(s); 167 struct bfs_inode_info *bi = BFS_I(inode); 168 169 dprintf("ino=%08lx\n", ino); 170 171 truncate_inode_pages_final(&inode->i_data); 172 invalidate_inode_buffers(inode); 173 clear_inode(inode); 174 175 if (inode->i_nlink) 176 return; 177 178 di = find_inode(s, inode->i_ino, &bh); 179 if (IS_ERR(di)) 180 return; 181 182 mutex_lock(&info->bfs_lock); 183 /* clear on-disk inode */ 184 memset(di, 0, sizeof(struct bfs_inode)); 185 mark_buffer_dirty(bh); 186 brelse(bh); 187 188 if (bi->i_dsk_ino) { 189 if (bi->i_sblock) 190 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock; 191 info->si_freei++; 192 clear_bit(ino, info->si_imap); 193 bfs_dump_imap("evict_inode", s); 194 } 195 196 /* 197 * If this was the last file, make the previous block 198 * "last block of the last file" even if there is no 199 * real file there, saves us 1 gap. 200 */ 201 if (info->si_lf_eblk == bi->i_eblock) 202 info->si_lf_eblk = bi->i_sblock - 1; 203 mutex_unlock(&info->bfs_lock); 204 } 205 206 static void bfs_put_super(struct super_block *s) 207 { 208 struct bfs_sb_info *info = BFS_SB(s); 209 210 if (!info) 211 return; 212 213 mutex_destroy(&info->bfs_lock); 214 kfree(info); 215 s->s_fs_info = NULL; 216 } 217 218 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf) 219 { 220 struct super_block *s = dentry->d_sb; 221 struct bfs_sb_info *info = BFS_SB(s); 222 u64 id = huge_encode_dev(s->s_bdev->bd_dev); 223 buf->f_type = BFS_MAGIC; 224 buf->f_bsize = s->s_blocksize; 225 buf->f_blocks = info->si_blocks; 226 buf->f_bfree = buf->f_bavail = info->si_freeb; 227 buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO; 228 buf->f_ffree = info->si_freei; 229 buf->f_fsid = u64_to_fsid(id); 230 buf->f_namelen = BFS_NAMELEN; 231 return 0; 232 } 233 234 static struct kmem_cache *bfs_inode_cachep; 235 236 static struct inode *bfs_alloc_inode(struct super_block *sb) 237 { 238 struct bfs_inode_info *bi; 239 bi = alloc_inode_sb(sb, bfs_inode_cachep, GFP_KERNEL); 240 if (!bi) 241 return NULL; 242 return &bi->vfs_inode; 243 } 244 245 static void bfs_free_inode(struct inode *inode) 246 { 247 kmem_cache_free(bfs_inode_cachep, BFS_I(inode)); 248 } 249 250 static void init_once(void *foo) 251 { 252 struct bfs_inode_info *bi = foo; 253 254 inode_init_once(&bi->vfs_inode); 255 } 256 257 static int __init init_inodecache(void) 258 { 259 bfs_inode_cachep = kmem_cache_create("bfs_inode_cache", 260 sizeof(struct bfs_inode_info), 261 0, (SLAB_RECLAIM_ACCOUNT| 262 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 263 init_once); 264 if (bfs_inode_cachep == NULL) 265 return -ENOMEM; 266 return 0; 267 } 268 269 static void destroy_inodecache(void) 270 { 271 /* 272 * Make sure all delayed rcu free inodes are flushed before we 273 * destroy cache. 274 */ 275 rcu_barrier(); 276 kmem_cache_destroy(bfs_inode_cachep); 277 } 278 279 static const struct super_operations bfs_sops = { 280 .alloc_inode = bfs_alloc_inode, 281 .free_inode = bfs_free_inode, 282 .write_inode = bfs_write_inode, 283 .evict_inode = bfs_evict_inode, 284 .put_super = bfs_put_super, 285 .statfs = bfs_statfs, 286 }; 287 288 void bfs_dump_imap(const char *prefix, struct super_block *s) 289 { 290 #ifdef DEBUG 291 int i; 292 char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL); 293 294 if (!tmpbuf) 295 return; 296 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) { 297 if (i > PAGE_SIZE - 100) break; 298 if (test_bit(i, BFS_SB(s)->si_imap)) 299 strcat(tmpbuf, "1"); 300 else 301 strcat(tmpbuf, "0"); 302 } 303 printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf); 304 free_page((unsigned long)tmpbuf); 305 #endif 306 } 307 308 static int bfs_fill_super(struct super_block *s, void *data, int silent) 309 { 310 struct buffer_head *bh, *sbh; 311 struct bfs_super_block *bfs_sb; 312 struct inode *inode; 313 unsigned i; 314 struct bfs_sb_info *info; 315 int ret = -EINVAL; 316 unsigned long i_sblock, i_eblock, i_eoff, s_size; 317 318 info = kzalloc(sizeof(*info), GFP_KERNEL); 319 if (!info) 320 return -ENOMEM; 321 mutex_init(&info->bfs_lock); 322 s->s_fs_info = info; 323 s->s_time_min = 0; 324 s->s_time_max = U32_MAX; 325 326 sb_set_blocksize(s, BFS_BSIZE); 327 328 sbh = sb_bread(s, 0); 329 if (!sbh) 330 goto out; 331 bfs_sb = (struct bfs_super_block *)sbh->b_data; 332 if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) { 333 if (!silent) 334 printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id, le32_to_cpu(bfs_sb->s_magic)); 335 goto out1; 336 } 337 if (BFS_UNCLEAN(bfs_sb, s) && !silent) 338 printf("%s is unclean, continuing\n", s->s_id); 339 340 s->s_magic = BFS_MAGIC; 341 342 if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) || 343 le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) { 344 printf("Superblock is corrupted on %s\n", s->s_id); 345 goto out1; 346 } 347 348 info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1; 349 if (info->si_lasti == BFS_MAX_LASTI) 350 printf("NOTE: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id); 351 else if (info->si_lasti > BFS_MAX_LASTI) { 352 printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id); 353 goto out1; 354 } 355 for (i = 0; i < BFS_ROOT_INO; i++) 356 set_bit(i, info->si_imap); 357 358 s->s_op = &bfs_sops; 359 inode = bfs_iget(s, BFS_ROOT_INO); 360 if (IS_ERR(inode)) { 361 ret = PTR_ERR(inode); 362 goto out1; 363 } 364 s->s_root = d_make_root(inode); 365 if (!s->s_root) { 366 ret = -ENOMEM; 367 goto out1; 368 } 369 370 info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS; 371 info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS; 372 info->si_freei = 0; 373 info->si_lf_eblk = 0; 374 375 /* can we read the last block? */ 376 bh = sb_bread(s, info->si_blocks - 1); 377 if (!bh) { 378 printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1); 379 ret = -EIO; 380 goto out2; 381 } 382 brelse(bh); 383 384 bh = NULL; 385 for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) { 386 struct bfs_inode *di; 387 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1; 388 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK; 389 unsigned long eblock; 390 391 if (!off) { 392 brelse(bh); 393 bh = sb_bread(s, block); 394 } 395 396 if (!bh) 397 continue; 398 399 di = (struct bfs_inode *)bh->b_data + off; 400 401 /* test if filesystem is not corrupted */ 402 403 i_eoff = le32_to_cpu(di->i_eoffset); 404 i_sblock = le32_to_cpu(di->i_sblock); 405 i_eblock = le32_to_cpu(di->i_eblock); 406 s_size = le32_to_cpu(bfs_sb->s_end); 407 408 if (i_sblock > info->si_blocks || 409 i_eblock > info->si_blocks || 410 i_sblock > i_eblock || 411 (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) || 412 i_sblock * BFS_BSIZE > i_eoff) { 413 414 printf("Inode 0x%08x corrupted on %s\n", i, s->s_id); 415 416 brelse(bh); 417 ret = -EIO; 418 goto out2; 419 } 420 421 if (!di->i_ino) { 422 info->si_freei++; 423 continue; 424 } 425 set_bit(i, info->si_imap); 426 info->si_freeb -= BFS_FILEBLOCKS(di); 427 428 eblock = le32_to_cpu(di->i_eblock); 429 if (eblock > info->si_lf_eblk) 430 info->si_lf_eblk = eblock; 431 } 432 brelse(bh); 433 brelse(sbh); 434 bfs_dump_imap("fill_super", s); 435 return 0; 436 437 out2: 438 dput(s->s_root); 439 s->s_root = NULL; 440 out1: 441 brelse(sbh); 442 out: 443 mutex_destroy(&info->bfs_lock); 444 kfree(info); 445 s->s_fs_info = NULL; 446 return ret; 447 } 448 449 static struct dentry *bfs_mount(struct file_system_type *fs_type, 450 int flags, const char *dev_name, void *data) 451 { 452 return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super); 453 } 454 455 static struct file_system_type bfs_fs_type = { 456 .owner = THIS_MODULE, 457 .name = "bfs", 458 .mount = bfs_mount, 459 .kill_sb = kill_block_super, 460 .fs_flags = FS_REQUIRES_DEV, 461 }; 462 MODULE_ALIAS_FS("bfs"); 463 464 static int __init init_bfs_fs(void) 465 { 466 int err = init_inodecache(); 467 if (err) 468 goto out1; 469 err = register_filesystem(&bfs_fs_type); 470 if (err) 471 goto out; 472 return 0; 473 out: 474 destroy_inodecache(); 475 out1: 476 return err; 477 } 478 479 static void __exit exit_bfs_fs(void) 480 { 481 unregister_filesystem(&bfs_fs_type); 482 destroy_inodecache(); 483 } 484 485 module_init(init_bfs_fs) 486 module_exit(exit_bfs_fs) 487