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_set_ctime(inode, le32_to_cpu(di->i_ctime), 0); 86 inode->i_atime.tv_nsec = 0; 87 inode->i_mtime.tv_nsec = 0; 88 89 brelse(bh); 90 unlock_new_inode(inode); 91 return inode; 92 93 error: 94 iget_failed(inode); 95 return ERR_PTR(-EIO); 96 } 97 98 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p) 99 { 100 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) { 101 printf("Bad inode number %s:%08x\n", sb->s_id, ino); 102 return ERR_PTR(-EIO); 103 } 104 105 ino -= BFS_ROOT_INO; 106 107 *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK); 108 if (!*p) { 109 printf("Unable to read inode %s:%08x\n", sb->s_id, ino); 110 return ERR_PTR(-EIO); 111 } 112 113 return (struct bfs_inode *)(*p)->b_data + ino % BFS_INODES_PER_BLOCK; 114 } 115 116 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc) 117 { 118 struct bfs_sb_info *info = BFS_SB(inode->i_sb); 119 unsigned int ino = (u16)inode->i_ino; 120 unsigned long i_sblock; 121 struct bfs_inode *di; 122 struct buffer_head *bh; 123 int err = 0; 124 125 dprintf("ino=%08x\n", ino); 126 127 di = find_inode(inode->i_sb, ino, &bh); 128 if (IS_ERR(di)) 129 return PTR_ERR(di); 130 131 mutex_lock(&info->bfs_lock); 132 133 if (ino == BFS_ROOT_INO) 134 di->i_vtype = cpu_to_le32(BFS_VDIR); 135 else 136 di->i_vtype = cpu_to_le32(BFS_VREG); 137 138 di->i_ino = cpu_to_le16(ino); 139 di->i_mode = cpu_to_le32(inode->i_mode); 140 di->i_uid = cpu_to_le32(i_uid_read(inode)); 141 di->i_gid = cpu_to_le32(i_gid_read(inode)); 142 di->i_nlink = cpu_to_le32(inode->i_nlink); 143 di->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 144 di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 145 di->i_ctime = cpu_to_le32(inode_get_ctime(inode).tv_sec); 146 i_sblock = BFS_I(inode)->i_sblock; 147 di->i_sblock = cpu_to_le32(i_sblock); 148 di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock); 149 di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1); 150 151 mark_buffer_dirty(bh); 152 if (wbc->sync_mode == WB_SYNC_ALL) { 153 sync_dirty_buffer(bh); 154 if (buffer_req(bh) && !buffer_uptodate(bh)) 155 err = -EIO; 156 } 157 brelse(bh); 158 mutex_unlock(&info->bfs_lock); 159 return err; 160 } 161 162 static void bfs_evict_inode(struct inode *inode) 163 { 164 unsigned long ino = inode->i_ino; 165 struct bfs_inode *di; 166 struct buffer_head *bh; 167 struct super_block *s = inode->i_sb; 168 struct bfs_sb_info *info = BFS_SB(s); 169 struct bfs_inode_info *bi = BFS_I(inode); 170 171 dprintf("ino=%08lx\n", ino); 172 173 truncate_inode_pages_final(&inode->i_data); 174 invalidate_inode_buffers(inode); 175 clear_inode(inode); 176 177 if (inode->i_nlink) 178 return; 179 180 di = find_inode(s, inode->i_ino, &bh); 181 if (IS_ERR(di)) 182 return; 183 184 mutex_lock(&info->bfs_lock); 185 /* clear on-disk inode */ 186 memset(di, 0, sizeof(struct bfs_inode)); 187 mark_buffer_dirty(bh); 188 brelse(bh); 189 190 if (bi->i_dsk_ino) { 191 if (bi->i_sblock) 192 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock; 193 info->si_freei++; 194 clear_bit(ino, info->si_imap); 195 bfs_dump_imap("evict_inode", s); 196 } 197 198 /* 199 * If this was the last file, make the previous block 200 * "last block of the last file" even if there is no 201 * real file there, saves us 1 gap. 202 */ 203 if (info->si_lf_eblk == bi->i_eblock) 204 info->si_lf_eblk = bi->i_sblock - 1; 205 mutex_unlock(&info->bfs_lock); 206 } 207 208 static void bfs_put_super(struct super_block *s) 209 { 210 struct bfs_sb_info *info = BFS_SB(s); 211 212 if (!info) 213 return; 214 215 mutex_destroy(&info->bfs_lock); 216 kfree(info); 217 s->s_fs_info = NULL; 218 } 219 220 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf) 221 { 222 struct super_block *s = dentry->d_sb; 223 struct bfs_sb_info *info = BFS_SB(s); 224 u64 id = huge_encode_dev(s->s_bdev->bd_dev); 225 buf->f_type = BFS_MAGIC; 226 buf->f_bsize = s->s_blocksize; 227 buf->f_blocks = info->si_blocks; 228 buf->f_bfree = buf->f_bavail = info->si_freeb; 229 buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO; 230 buf->f_ffree = info->si_freei; 231 buf->f_fsid = u64_to_fsid(id); 232 buf->f_namelen = BFS_NAMELEN; 233 return 0; 234 } 235 236 static struct kmem_cache *bfs_inode_cachep; 237 238 static struct inode *bfs_alloc_inode(struct super_block *sb) 239 { 240 struct bfs_inode_info *bi; 241 bi = alloc_inode_sb(sb, bfs_inode_cachep, GFP_KERNEL); 242 if (!bi) 243 return NULL; 244 return &bi->vfs_inode; 245 } 246 247 static void bfs_free_inode(struct inode *inode) 248 { 249 kmem_cache_free(bfs_inode_cachep, BFS_I(inode)); 250 } 251 252 static void init_once(void *foo) 253 { 254 struct bfs_inode_info *bi = foo; 255 256 inode_init_once(&bi->vfs_inode); 257 } 258 259 static int __init init_inodecache(void) 260 { 261 bfs_inode_cachep = kmem_cache_create("bfs_inode_cache", 262 sizeof(struct bfs_inode_info), 263 0, (SLAB_RECLAIM_ACCOUNT| 264 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 265 init_once); 266 if (bfs_inode_cachep == NULL) 267 return -ENOMEM; 268 return 0; 269 } 270 271 static void destroy_inodecache(void) 272 { 273 /* 274 * Make sure all delayed rcu free inodes are flushed before we 275 * destroy cache. 276 */ 277 rcu_barrier(); 278 kmem_cache_destroy(bfs_inode_cachep); 279 } 280 281 static const struct super_operations bfs_sops = { 282 .alloc_inode = bfs_alloc_inode, 283 .free_inode = bfs_free_inode, 284 .write_inode = bfs_write_inode, 285 .evict_inode = bfs_evict_inode, 286 .put_super = bfs_put_super, 287 .statfs = bfs_statfs, 288 }; 289 290 void bfs_dump_imap(const char *prefix, struct super_block *s) 291 { 292 #ifdef DEBUG 293 int i; 294 char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL); 295 296 if (!tmpbuf) 297 return; 298 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) { 299 if (i > PAGE_SIZE - 100) break; 300 if (test_bit(i, BFS_SB(s)->si_imap)) 301 strcat(tmpbuf, "1"); 302 else 303 strcat(tmpbuf, "0"); 304 } 305 printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf); 306 free_page((unsigned long)tmpbuf); 307 #endif 308 } 309 310 static int bfs_fill_super(struct super_block *s, void *data, int silent) 311 { 312 struct buffer_head *bh, *sbh; 313 struct bfs_super_block *bfs_sb; 314 struct inode *inode; 315 unsigned i; 316 struct bfs_sb_info *info; 317 int ret = -EINVAL; 318 unsigned long i_sblock, i_eblock, i_eoff, s_size; 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 struct dentry *bfs_mount(struct file_system_type *fs_type, 452 int flags, const char *dev_name, void *data) 453 { 454 return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super); 455 } 456 457 static struct file_system_type bfs_fs_type = { 458 .owner = THIS_MODULE, 459 .name = "bfs", 460 .mount = bfs_mount, 461 .kill_sb = kill_block_super, 462 .fs_flags = FS_REQUIRES_DEV, 463 }; 464 MODULE_ALIAS_FS("bfs"); 465 466 static int __init init_bfs_fs(void) 467 { 468 int err = init_inodecache(); 469 if (err) 470 goto out1; 471 err = register_filesystem(&bfs_fs_type); 472 if (err) 473 goto out; 474 return 0; 475 out: 476 destroy_inodecache(); 477 out1: 478 return err; 479 } 480 481 static void __exit exit_bfs_fs(void) 482 { 483 unregister_filesystem(&bfs_fs_type); 484 destroy_inodecache(); 485 } 486 487 module_init(init_bfs_fs) 488 module_exit(exit_bfs_fs) 489