1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2017-2018 HUAWEI, Inc. 4 * https://www.huawei.com/ 5 * Copyright (C) 2021, Alibaba Cloud 6 */ 7 #include <linux/statfs.h> 8 #include <linux/seq_file.h> 9 #include <linux/crc32c.h> 10 #include <linux/fs_context.h> 11 #include <linux/fs_parser.h> 12 #include <linux/exportfs.h> 13 #include <linux/backing-dev.h> 14 #include "xattr.h" 15 16 #define CREATE_TRACE_POINTS 17 #include <trace/events/erofs.h> 18 19 static struct kmem_cache *erofs_inode_cachep __read_mostly; 20 21 void _erofs_printk(struct super_block *sb, const char *fmt, ...) 22 { 23 struct va_format vaf; 24 va_list args; 25 int level; 26 27 va_start(args, fmt); 28 29 level = printk_get_level(fmt); 30 vaf.fmt = printk_skip_level(fmt); 31 vaf.va = &args; 32 if (sb) 33 printk("%c%cerofs (device %s): %pV", 34 KERN_SOH_ASCII, level, sb->s_id, &vaf); 35 else 36 printk("%c%cerofs: %pV", KERN_SOH_ASCII, level, &vaf); 37 va_end(args); 38 } 39 40 static int erofs_superblock_csum_verify(struct super_block *sb, void *sbdata) 41 { 42 struct erofs_super_block *dsb = sbdata + EROFS_SUPER_OFFSET; 43 u32 len = 1 << EROFS_SB(sb)->blkszbits, crc; 44 45 if (len > EROFS_SUPER_OFFSET) 46 len -= EROFS_SUPER_OFFSET; 47 len -= offsetof(struct erofs_super_block, checksum) + 48 sizeof(dsb->checksum); 49 50 /* skip .magic(pre-verified) and .checksum(0) fields */ 51 crc = crc32c(0x5045B54A, (&dsb->checksum) + 1, len); 52 if (crc == le32_to_cpu(dsb->checksum)) 53 return 0; 54 erofs_err(sb, "invalid checksum 0x%08x, 0x%08x expected", 55 crc, le32_to_cpu(dsb->checksum)); 56 return -EBADMSG; 57 } 58 59 static void erofs_inode_init_once(void *ptr) 60 { 61 struct erofs_inode *vi = ptr; 62 63 inode_init_once(&vi->vfs_inode); 64 } 65 66 static struct inode *erofs_alloc_inode(struct super_block *sb) 67 { 68 struct erofs_inode *vi = 69 alloc_inode_sb(sb, erofs_inode_cachep, GFP_KERNEL); 70 71 if (!vi) 72 return NULL; 73 74 /* zero out everything except vfs_inode */ 75 memset(vi, 0, offsetof(struct erofs_inode, vfs_inode)); 76 return &vi->vfs_inode; 77 } 78 79 static void erofs_free_inode(struct inode *inode) 80 { 81 struct erofs_inode *vi = EROFS_I(inode); 82 83 if (inode->i_op == &erofs_fast_symlink_iops) 84 kfree(inode->i_link); 85 kfree(vi->xattr_shared_xattrs); 86 kmem_cache_free(erofs_inode_cachep, vi); 87 } 88 89 /* read variable-sized metadata, offset will be aligned by 4-byte */ 90 void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf, 91 erofs_off_t *offset, int *lengthp) 92 { 93 u8 *buffer, *ptr; 94 int len, i, cnt; 95 96 *offset = round_up(*offset, 4); 97 ptr = erofs_bread(buf, *offset, EROFS_KMAP); 98 if (IS_ERR(ptr)) 99 return ptr; 100 101 len = le16_to_cpu(*(__le16 *)ptr); 102 if (!len) 103 len = U16_MAX + 1; 104 buffer = kmalloc(len, GFP_KERNEL); 105 if (!buffer) 106 return ERR_PTR(-ENOMEM); 107 *offset += sizeof(__le16); 108 *lengthp = len; 109 110 for (i = 0; i < len; i += cnt) { 111 cnt = min_t(int, sb->s_blocksize - erofs_blkoff(sb, *offset), 112 len - i); 113 ptr = erofs_bread(buf, *offset, EROFS_KMAP); 114 if (IS_ERR(ptr)) { 115 kfree(buffer); 116 return ptr; 117 } 118 memcpy(buffer + i, ptr, cnt); 119 *offset += cnt; 120 } 121 return buffer; 122 } 123 124 #ifndef CONFIG_EROFS_FS_ZIP 125 static int z_erofs_parse_cfgs(struct super_block *sb, 126 struct erofs_super_block *dsb) 127 { 128 if (!dsb->u1.available_compr_algs) 129 return 0; 130 131 erofs_err(sb, "compression disabled, unable to mount compressed EROFS"); 132 return -EOPNOTSUPP; 133 } 134 #endif 135 136 static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb, 137 struct erofs_device_info *dif, erofs_off_t *pos) 138 { 139 struct erofs_sb_info *sbi = EROFS_SB(sb); 140 struct erofs_fscache *fscache; 141 struct erofs_deviceslot *dis; 142 struct file *file; 143 144 dis = erofs_read_metabuf(buf, sb, *pos, EROFS_KMAP); 145 if (IS_ERR(dis)) 146 return PTR_ERR(dis); 147 148 if (!sbi->devs->flatdev && !dif->path) { 149 if (!dis->tag[0]) { 150 erofs_err(sb, "empty device tag @ pos %llu", *pos); 151 return -EINVAL; 152 } 153 dif->path = kmemdup_nul(dis->tag, sizeof(dis->tag), GFP_KERNEL); 154 if (!dif->path) 155 return -ENOMEM; 156 } 157 158 if (erofs_is_fscache_mode(sb)) { 159 fscache = erofs_fscache_register_cookie(sb, dif->path, 0); 160 if (IS_ERR(fscache)) 161 return PTR_ERR(fscache); 162 dif->fscache = fscache; 163 } else if (!sbi->devs->flatdev) { 164 file = erofs_is_fileio_mode(sbi) ? 165 filp_open(dif->path, O_RDONLY | O_LARGEFILE, 0) : 166 bdev_file_open_by_path(dif->path, 167 BLK_OPEN_READ, sb->s_type, NULL); 168 if (IS_ERR(file)) 169 return PTR_ERR(file); 170 171 if (!erofs_is_fileio_mode(sbi)) { 172 dif->dax_dev = fs_dax_get_by_bdev(file_bdev(file), 173 &dif->dax_part_off, NULL, NULL); 174 } else if (!S_ISREG(file_inode(file)->i_mode)) { 175 fput(file); 176 return -EINVAL; 177 } 178 dif->file = file; 179 } 180 181 dif->blocks = le32_to_cpu(dis->blocks); 182 dif->mapped_blkaddr = le32_to_cpu(dis->mapped_blkaddr); 183 sbi->total_blocks += dif->blocks; 184 *pos += EROFS_DEVT_SLOT_SIZE; 185 return 0; 186 } 187 188 static int erofs_scan_devices(struct super_block *sb, 189 struct erofs_super_block *dsb) 190 { 191 struct erofs_sb_info *sbi = EROFS_SB(sb); 192 unsigned int ondisk_extradevs; 193 erofs_off_t pos; 194 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 195 struct erofs_device_info *dif; 196 int id, err = 0; 197 198 sbi->total_blocks = sbi->dif0.blocks; 199 if (!erofs_sb_has_device_table(sbi)) 200 ondisk_extradevs = 0; 201 else 202 ondisk_extradevs = le16_to_cpu(dsb->extra_devices); 203 204 if (sbi->devs->extra_devices && 205 ondisk_extradevs != sbi->devs->extra_devices) { 206 erofs_err(sb, "extra devices don't match (ondisk %u, given %u)", 207 ondisk_extradevs, sbi->devs->extra_devices); 208 return -EINVAL; 209 } 210 if (!ondisk_extradevs) 211 return 0; 212 213 if (!sbi->devs->extra_devices && !erofs_is_fscache_mode(sb)) 214 sbi->devs->flatdev = true; 215 216 sbi->device_id_mask = roundup_pow_of_two(ondisk_extradevs + 1) - 1; 217 pos = le16_to_cpu(dsb->devt_slotoff) * EROFS_DEVT_SLOT_SIZE; 218 down_read(&sbi->devs->rwsem); 219 if (sbi->devs->extra_devices) { 220 idr_for_each_entry(&sbi->devs->tree, dif, id) { 221 err = erofs_init_device(&buf, sb, dif, &pos); 222 if (err) 223 break; 224 } 225 } else { 226 for (id = 0; id < ondisk_extradevs; id++) { 227 dif = kzalloc(sizeof(*dif), GFP_KERNEL); 228 if (!dif) { 229 err = -ENOMEM; 230 break; 231 } 232 233 err = idr_alloc(&sbi->devs->tree, dif, 0, 0, GFP_KERNEL); 234 if (err < 0) { 235 kfree(dif); 236 break; 237 } 238 ++sbi->devs->extra_devices; 239 240 err = erofs_init_device(&buf, sb, dif, &pos); 241 if (err) 242 break; 243 } 244 } 245 up_read(&sbi->devs->rwsem); 246 erofs_put_metabuf(&buf); 247 return err; 248 } 249 250 static int erofs_read_superblock(struct super_block *sb) 251 { 252 struct erofs_sb_info *sbi = EROFS_SB(sb); 253 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 254 struct erofs_super_block *dsb; 255 void *data; 256 int ret; 257 258 data = erofs_read_metabuf(&buf, sb, 0, EROFS_KMAP); 259 if (IS_ERR(data)) { 260 erofs_err(sb, "cannot read erofs superblock"); 261 return PTR_ERR(data); 262 } 263 264 dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET); 265 ret = -EINVAL; 266 if (le32_to_cpu(dsb->magic) != EROFS_SUPER_MAGIC_V1) { 267 erofs_err(sb, "cannot find valid erofs superblock"); 268 goto out; 269 } 270 271 sbi->blkszbits = dsb->blkszbits; 272 if (sbi->blkszbits < 9 || sbi->blkszbits > PAGE_SHIFT) { 273 erofs_err(sb, "blkszbits %u isn't supported", sbi->blkszbits); 274 goto out; 275 } 276 if (dsb->dirblkbits) { 277 erofs_err(sb, "dirblkbits %u isn't supported", dsb->dirblkbits); 278 goto out; 279 } 280 281 sbi->feature_compat = le32_to_cpu(dsb->feature_compat); 282 if (erofs_sb_has_sb_chksum(sbi)) { 283 ret = erofs_superblock_csum_verify(sb, data); 284 if (ret) 285 goto out; 286 } 287 288 ret = -EINVAL; 289 sbi->feature_incompat = le32_to_cpu(dsb->feature_incompat); 290 if (sbi->feature_incompat & ~EROFS_ALL_FEATURE_INCOMPAT) { 291 erofs_err(sb, "unidentified incompatible feature %x, please upgrade kernel", 292 sbi->feature_incompat & ~EROFS_ALL_FEATURE_INCOMPAT); 293 goto out; 294 } 295 296 sbi->sb_size = 128 + dsb->sb_extslots * EROFS_SB_EXTSLOT_SIZE; 297 if (sbi->sb_size > PAGE_SIZE - EROFS_SUPER_OFFSET) { 298 erofs_err(sb, "invalid sb_extslots %u (more than a fs block)", 299 sbi->sb_size); 300 goto out; 301 } 302 sbi->dif0.blocks = le32_to_cpu(dsb->blocks); 303 sbi->meta_blkaddr = le32_to_cpu(dsb->meta_blkaddr); 304 #ifdef CONFIG_EROFS_FS_XATTR 305 sbi->xattr_blkaddr = le32_to_cpu(dsb->xattr_blkaddr); 306 sbi->xattr_prefix_start = le32_to_cpu(dsb->xattr_prefix_start); 307 sbi->xattr_prefix_count = dsb->xattr_prefix_count; 308 sbi->xattr_filter_reserved = dsb->xattr_filter_reserved; 309 #endif 310 sbi->islotbits = ilog2(sizeof(struct erofs_inode_compact)); 311 sbi->root_nid = le16_to_cpu(dsb->root_nid); 312 sbi->packed_nid = le64_to_cpu(dsb->packed_nid); 313 sbi->inos = le64_to_cpu(dsb->inos); 314 315 sbi->build_time = le64_to_cpu(dsb->build_time); 316 sbi->build_time_nsec = le32_to_cpu(dsb->build_time_nsec); 317 318 super_set_uuid(sb, (void *)dsb->uuid, sizeof(dsb->uuid)); 319 320 ret = strscpy(sbi->volume_name, dsb->volume_name, 321 sizeof(dsb->volume_name)); 322 if (ret < 0) { /* -E2BIG */ 323 erofs_err(sb, "bad volume name without NIL terminator"); 324 ret = -EFSCORRUPTED; 325 goto out; 326 } 327 328 /* parse on-disk compression configurations */ 329 ret = z_erofs_parse_cfgs(sb, dsb); 330 if (ret < 0) 331 goto out; 332 333 /* handle multiple devices */ 334 ret = erofs_scan_devices(sb, dsb); 335 336 if (erofs_is_fscache_mode(sb)) 337 erofs_info(sb, "[deprecated] fscache-based on-demand read feature in use. Use at your own risk!"); 338 out: 339 erofs_put_metabuf(&buf); 340 return ret; 341 } 342 343 static void erofs_default_options(struct erofs_sb_info *sbi) 344 { 345 #ifdef CONFIG_EROFS_FS_ZIP 346 sbi->opt.cache_strategy = EROFS_ZIP_CACHE_READAROUND; 347 sbi->opt.max_sync_decompress_pages = 3; 348 sbi->opt.sync_decompress = EROFS_SYNC_DECOMPRESS_AUTO; 349 #endif 350 #ifdef CONFIG_EROFS_FS_XATTR 351 set_opt(&sbi->opt, XATTR_USER); 352 #endif 353 #ifdef CONFIG_EROFS_FS_POSIX_ACL 354 set_opt(&sbi->opt, POSIX_ACL); 355 #endif 356 } 357 358 enum { 359 Opt_user_xattr, Opt_acl, Opt_cache_strategy, Opt_dax, Opt_dax_enum, 360 Opt_device, Opt_fsid, Opt_domain_id, Opt_directio, 361 Opt_err 362 }; 363 364 static const struct constant_table erofs_param_cache_strategy[] = { 365 {"disabled", EROFS_ZIP_CACHE_DISABLED}, 366 {"readahead", EROFS_ZIP_CACHE_READAHEAD}, 367 {"readaround", EROFS_ZIP_CACHE_READAROUND}, 368 {} 369 }; 370 371 static const struct constant_table erofs_dax_param_enums[] = { 372 {"always", EROFS_MOUNT_DAX_ALWAYS}, 373 {"never", EROFS_MOUNT_DAX_NEVER}, 374 {} 375 }; 376 377 static const struct fs_parameter_spec erofs_fs_parameters[] = { 378 fsparam_flag_no("user_xattr", Opt_user_xattr), 379 fsparam_flag_no("acl", Opt_acl), 380 fsparam_enum("cache_strategy", Opt_cache_strategy, 381 erofs_param_cache_strategy), 382 fsparam_flag("dax", Opt_dax), 383 fsparam_enum("dax", Opt_dax_enum, erofs_dax_param_enums), 384 fsparam_string("device", Opt_device), 385 fsparam_string("fsid", Opt_fsid), 386 fsparam_string("domain_id", Opt_domain_id), 387 fsparam_flag_no("directio", Opt_directio), 388 {} 389 }; 390 391 static bool erofs_fc_set_dax_mode(struct fs_context *fc, unsigned int mode) 392 { 393 #ifdef CONFIG_FS_DAX 394 struct erofs_sb_info *sbi = fc->s_fs_info; 395 396 switch (mode) { 397 case EROFS_MOUNT_DAX_ALWAYS: 398 set_opt(&sbi->opt, DAX_ALWAYS); 399 clear_opt(&sbi->opt, DAX_NEVER); 400 return true; 401 case EROFS_MOUNT_DAX_NEVER: 402 set_opt(&sbi->opt, DAX_NEVER); 403 clear_opt(&sbi->opt, DAX_ALWAYS); 404 return true; 405 default: 406 DBG_BUGON(1); 407 return false; 408 } 409 #else 410 errorfc(fc, "dax options not supported"); 411 return false; 412 #endif 413 } 414 415 static int erofs_fc_parse_param(struct fs_context *fc, 416 struct fs_parameter *param) 417 { 418 struct erofs_sb_info *sbi = fc->s_fs_info; 419 struct fs_parse_result result; 420 struct erofs_device_info *dif; 421 int opt, ret; 422 423 opt = fs_parse(fc, erofs_fs_parameters, param, &result); 424 if (opt < 0) 425 return opt; 426 427 switch (opt) { 428 case Opt_user_xattr: 429 #ifdef CONFIG_EROFS_FS_XATTR 430 if (result.boolean) 431 set_opt(&sbi->opt, XATTR_USER); 432 else 433 clear_opt(&sbi->opt, XATTR_USER); 434 #else 435 errorfc(fc, "{,no}user_xattr options not supported"); 436 #endif 437 break; 438 case Opt_acl: 439 #ifdef CONFIG_EROFS_FS_POSIX_ACL 440 if (result.boolean) 441 set_opt(&sbi->opt, POSIX_ACL); 442 else 443 clear_opt(&sbi->opt, POSIX_ACL); 444 #else 445 errorfc(fc, "{,no}acl options not supported"); 446 #endif 447 break; 448 case Opt_cache_strategy: 449 #ifdef CONFIG_EROFS_FS_ZIP 450 sbi->opt.cache_strategy = result.uint_32; 451 #else 452 errorfc(fc, "compression not supported, cache_strategy ignored"); 453 #endif 454 break; 455 case Opt_dax: 456 if (!erofs_fc_set_dax_mode(fc, EROFS_MOUNT_DAX_ALWAYS)) 457 return -EINVAL; 458 break; 459 case Opt_dax_enum: 460 if (!erofs_fc_set_dax_mode(fc, result.uint_32)) 461 return -EINVAL; 462 break; 463 case Opt_device: 464 dif = kzalloc(sizeof(*dif), GFP_KERNEL); 465 if (!dif) 466 return -ENOMEM; 467 dif->path = kstrdup(param->string, GFP_KERNEL); 468 if (!dif->path) { 469 kfree(dif); 470 return -ENOMEM; 471 } 472 down_write(&sbi->devs->rwsem); 473 ret = idr_alloc(&sbi->devs->tree, dif, 0, 0, GFP_KERNEL); 474 up_write(&sbi->devs->rwsem); 475 if (ret < 0) { 476 kfree(dif->path); 477 kfree(dif); 478 return ret; 479 } 480 ++sbi->devs->extra_devices; 481 break; 482 #ifdef CONFIG_EROFS_FS_ONDEMAND 483 case Opt_fsid: 484 kfree(sbi->fsid); 485 sbi->fsid = kstrdup(param->string, GFP_KERNEL); 486 if (!sbi->fsid) 487 return -ENOMEM; 488 break; 489 case Opt_domain_id: 490 kfree(sbi->domain_id); 491 sbi->domain_id = kstrdup(param->string, GFP_KERNEL); 492 if (!sbi->domain_id) 493 return -ENOMEM; 494 break; 495 #else 496 case Opt_fsid: 497 case Opt_domain_id: 498 errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name); 499 break; 500 #endif 501 case Opt_directio: 502 #ifdef CONFIG_EROFS_FS_BACKED_BY_FILE 503 if (result.boolean) 504 set_opt(&sbi->opt, DIRECT_IO); 505 else 506 clear_opt(&sbi->opt, DIRECT_IO); 507 #else 508 errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name); 509 #endif 510 break; 511 } 512 return 0; 513 } 514 515 static struct inode *erofs_nfs_get_inode(struct super_block *sb, 516 u64 ino, u32 generation) 517 { 518 return erofs_iget(sb, ino); 519 } 520 521 static struct dentry *erofs_fh_to_dentry(struct super_block *sb, 522 struct fid *fid, int fh_len, int fh_type) 523 { 524 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 525 erofs_nfs_get_inode); 526 } 527 528 static struct dentry *erofs_fh_to_parent(struct super_block *sb, 529 struct fid *fid, int fh_len, int fh_type) 530 { 531 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 532 erofs_nfs_get_inode); 533 } 534 535 static struct dentry *erofs_get_parent(struct dentry *child) 536 { 537 erofs_nid_t nid; 538 unsigned int d_type; 539 int err; 540 541 err = erofs_namei(d_inode(child), &dotdot_name, &nid, &d_type); 542 if (err) 543 return ERR_PTR(err); 544 return d_obtain_alias(erofs_iget(child->d_sb, nid)); 545 } 546 547 static const struct export_operations erofs_export_ops = { 548 .encode_fh = generic_encode_ino32_fh, 549 .fh_to_dentry = erofs_fh_to_dentry, 550 .fh_to_parent = erofs_fh_to_parent, 551 .get_parent = erofs_get_parent, 552 }; 553 554 static void erofs_set_sysfs_name(struct super_block *sb) 555 { 556 struct erofs_sb_info *sbi = EROFS_SB(sb); 557 558 if (sbi->domain_id) 559 super_set_sysfs_name_generic(sb, "%s,%s", sbi->domain_id, 560 sbi->fsid); 561 else if (sbi->fsid) 562 super_set_sysfs_name_generic(sb, "%s", sbi->fsid); 563 else if (erofs_is_fileio_mode(sbi)) 564 super_set_sysfs_name_generic(sb, "%s", 565 bdi_dev_name(sb->s_bdi)); 566 else 567 super_set_sysfs_name_id(sb); 568 } 569 570 static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) 571 { 572 struct inode *inode; 573 struct erofs_sb_info *sbi = EROFS_SB(sb); 574 int err; 575 576 sb->s_magic = EROFS_SUPER_MAGIC; 577 sb->s_flags |= SB_RDONLY | SB_NOATIME; 578 sb->s_maxbytes = MAX_LFS_FILESIZE; 579 sb->s_op = &erofs_sops; 580 581 sbi->blkszbits = PAGE_SHIFT; 582 if (!sb->s_bdev) { 583 sb->s_blocksize = PAGE_SIZE; 584 sb->s_blocksize_bits = PAGE_SHIFT; 585 586 if (erofs_is_fscache_mode(sb)) { 587 err = erofs_fscache_register_fs(sb); 588 if (err) 589 return err; 590 } 591 err = super_setup_bdi(sb); 592 if (err) 593 return err; 594 } else { 595 if (!sb_set_blocksize(sb, PAGE_SIZE)) { 596 errorfc(fc, "failed to set initial blksize"); 597 return -EINVAL; 598 } 599 600 sbi->dif0.dax_dev = fs_dax_get_by_bdev(sb->s_bdev, 601 &sbi->dif0.dax_part_off, NULL, NULL); 602 } 603 604 err = erofs_read_superblock(sb); 605 if (err) 606 return err; 607 608 if (sb->s_blocksize_bits != sbi->blkszbits) { 609 if (erofs_is_fscache_mode(sb)) { 610 errorfc(fc, "unsupported blksize for fscache mode"); 611 return -EINVAL; 612 } 613 614 if (erofs_is_fileio_mode(sbi)) { 615 sb->s_blocksize = 1 << sbi->blkszbits; 616 sb->s_blocksize_bits = sbi->blkszbits; 617 } else if (!sb_set_blocksize(sb, 1 << sbi->blkszbits)) { 618 errorfc(fc, "failed to set erofs blksize"); 619 return -EINVAL; 620 } 621 } 622 623 if (test_opt(&sbi->opt, DAX_ALWAYS)) { 624 if (!sbi->dif0.dax_dev) { 625 errorfc(fc, "DAX unsupported by block device. Turning off DAX."); 626 clear_opt(&sbi->opt, DAX_ALWAYS); 627 } else if (sbi->blkszbits != PAGE_SHIFT) { 628 errorfc(fc, "unsupported blocksize for DAX"); 629 clear_opt(&sbi->opt, DAX_ALWAYS); 630 } 631 } 632 633 sb->s_time_gran = 1; 634 sb->s_xattr = erofs_xattr_handlers; 635 sb->s_export_op = &erofs_export_ops; 636 637 if (test_opt(&sbi->opt, POSIX_ACL)) 638 sb->s_flags |= SB_POSIXACL; 639 else 640 sb->s_flags &= ~SB_POSIXACL; 641 642 #ifdef CONFIG_EROFS_FS_ZIP 643 xa_init(&sbi->managed_pslots); 644 #endif 645 646 inode = erofs_iget(sb, sbi->root_nid); 647 if (IS_ERR(inode)) 648 return PTR_ERR(inode); 649 650 if (!S_ISDIR(inode->i_mode)) { 651 erofs_err(sb, "rootino(nid %llu) is not a directory(i_mode %o)", 652 sbi->root_nid, inode->i_mode); 653 iput(inode); 654 return -EINVAL; 655 } 656 657 sb->s_root = d_make_root(inode); 658 if (!sb->s_root) 659 return -ENOMEM; 660 661 erofs_shrinker_register(sb); 662 if (erofs_sb_has_fragments(sbi) && sbi->packed_nid) { 663 sbi->packed_inode = erofs_iget(sb, sbi->packed_nid); 664 if (IS_ERR(sbi->packed_inode)) { 665 err = PTR_ERR(sbi->packed_inode); 666 sbi->packed_inode = NULL; 667 return err; 668 } 669 } 670 err = erofs_init_managed_cache(sb); 671 if (err) 672 return err; 673 674 err = erofs_xattr_prefixes_init(sb); 675 if (err) 676 return err; 677 678 erofs_set_sysfs_name(sb); 679 err = erofs_register_sysfs(sb); 680 if (err) 681 return err; 682 683 erofs_info(sb, "mounted with root inode @ nid %llu.", sbi->root_nid); 684 return 0; 685 } 686 687 static int erofs_fc_get_tree(struct fs_context *fc) 688 { 689 struct erofs_sb_info *sbi = fc->s_fs_info; 690 int ret; 691 692 if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && sbi->fsid) 693 return get_tree_nodev(fc, erofs_fc_fill_super); 694 695 ret = get_tree_bdev_flags(fc, erofs_fc_fill_super, 696 IS_ENABLED(CONFIG_EROFS_FS_BACKED_BY_FILE) ? 697 GET_TREE_BDEV_QUIET_LOOKUP : 0); 698 #ifdef CONFIG_EROFS_FS_BACKED_BY_FILE 699 if (ret == -ENOTBLK) { 700 struct file *file; 701 702 if (!fc->source) 703 return invalf(fc, "No source specified"); 704 file = filp_open(fc->source, O_RDONLY | O_LARGEFILE, 0); 705 if (IS_ERR(file)) 706 return PTR_ERR(file); 707 sbi->dif0.file = file; 708 709 if (S_ISREG(file_inode(sbi->dif0.file)->i_mode) && 710 sbi->dif0.file->f_mapping->a_ops->read_folio) 711 return get_tree_nodev(fc, erofs_fc_fill_super); 712 } 713 #endif 714 return ret; 715 } 716 717 static int erofs_fc_reconfigure(struct fs_context *fc) 718 { 719 struct super_block *sb = fc->root->d_sb; 720 struct erofs_sb_info *sbi = EROFS_SB(sb); 721 struct erofs_sb_info *new_sbi = fc->s_fs_info; 722 723 DBG_BUGON(!sb_rdonly(sb)); 724 725 if (new_sbi->fsid || new_sbi->domain_id) 726 erofs_info(sb, "ignoring reconfiguration for fsid|domain_id."); 727 728 if (test_opt(&new_sbi->opt, POSIX_ACL)) 729 fc->sb_flags |= SB_POSIXACL; 730 else 731 fc->sb_flags &= ~SB_POSIXACL; 732 733 sbi->opt = new_sbi->opt; 734 735 fc->sb_flags |= SB_RDONLY; 736 return 0; 737 } 738 739 static int erofs_release_device_info(int id, void *ptr, void *data) 740 { 741 struct erofs_device_info *dif = ptr; 742 743 fs_put_dax(dif->dax_dev, NULL); 744 if (dif->file) 745 fput(dif->file); 746 erofs_fscache_unregister_cookie(dif->fscache); 747 dif->fscache = NULL; 748 kfree(dif->path); 749 kfree(dif); 750 return 0; 751 } 752 753 static void erofs_free_dev_context(struct erofs_dev_context *devs) 754 { 755 if (!devs) 756 return; 757 idr_for_each(&devs->tree, &erofs_release_device_info, NULL); 758 idr_destroy(&devs->tree); 759 kfree(devs); 760 } 761 762 static void erofs_sb_free(struct erofs_sb_info *sbi) 763 { 764 erofs_free_dev_context(sbi->devs); 765 kfree(sbi->fsid); 766 kfree(sbi->domain_id); 767 if (sbi->dif0.file) 768 fput(sbi->dif0.file); 769 kfree(sbi); 770 } 771 772 static void erofs_fc_free(struct fs_context *fc) 773 { 774 struct erofs_sb_info *sbi = fc->s_fs_info; 775 776 if (sbi) /* free here if an error occurs before transferring to sb */ 777 erofs_sb_free(sbi); 778 } 779 780 static const struct fs_context_operations erofs_context_ops = { 781 .parse_param = erofs_fc_parse_param, 782 .get_tree = erofs_fc_get_tree, 783 .reconfigure = erofs_fc_reconfigure, 784 .free = erofs_fc_free, 785 }; 786 787 static int erofs_init_fs_context(struct fs_context *fc) 788 { 789 struct erofs_sb_info *sbi; 790 791 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 792 if (!sbi) 793 return -ENOMEM; 794 795 sbi->devs = kzalloc(sizeof(struct erofs_dev_context), GFP_KERNEL); 796 if (!sbi->devs) { 797 kfree(sbi); 798 return -ENOMEM; 799 } 800 fc->s_fs_info = sbi; 801 802 idr_init(&sbi->devs->tree); 803 init_rwsem(&sbi->devs->rwsem); 804 erofs_default_options(sbi); 805 fc->ops = &erofs_context_ops; 806 return 0; 807 } 808 809 static void erofs_kill_sb(struct super_block *sb) 810 { 811 struct erofs_sb_info *sbi = EROFS_SB(sb); 812 813 if ((IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && sbi->fsid) || 814 sbi->dif0.file) 815 kill_anon_super(sb); 816 else 817 kill_block_super(sb); 818 fs_put_dax(sbi->dif0.dax_dev, NULL); 819 erofs_fscache_unregister_fs(sb); 820 erofs_sb_free(sbi); 821 sb->s_fs_info = NULL; 822 } 823 824 static void erofs_put_super(struct super_block *sb) 825 { 826 struct erofs_sb_info *const sbi = EROFS_SB(sb); 827 828 DBG_BUGON(!sbi); 829 830 erofs_unregister_sysfs(sb); 831 erofs_shrinker_unregister(sb); 832 erofs_xattr_prefixes_cleanup(sb); 833 #ifdef CONFIG_EROFS_FS_ZIP 834 iput(sbi->managed_cache); 835 sbi->managed_cache = NULL; 836 #endif 837 iput(sbi->packed_inode); 838 sbi->packed_inode = NULL; 839 erofs_free_dev_context(sbi->devs); 840 sbi->devs = NULL; 841 erofs_fscache_unregister_fs(sb); 842 } 843 844 static struct file_system_type erofs_fs_type = { 845 .owner = THIS_MODULE, 846 .name = "erofs", 847 .init_fs_context = erofs_init_fs_context, 848 .kill_sb = erofs_kill_sb, 849 .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, 850 }; 851 MODULE_ALIAS_FS("erofs"); 852 853 static int __init erofs_module_init(void) 854 { 855 int err; 856 857 erofs_check_ondisk_layout_definitions(); 858 859 erofs_inode_cachep = kmem_cache_create("erofs_inode", 860 sizeof(struct erofs_inode), 0, 861 SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT, 862 erofs_inode_init_once); 863 if (!erofs_inode_cachep) 864 return -ENOMEM; 865 866 err = erofs_init_shrinker(); 867 if (err) 868 goto shrinker_err; 869 870 err = z_erofs_init_subsystem(); 871 if (err) 872 goto zip_err; 873 874 err = erofs_init_sysfs(); 875 if (err) 876 goto sysfs_err; 877 878 err = register_filesystem(&erofs_fs_type); 879 if (err) 880 goto fs_err; 881 882 return 0; 883 884 fs_err: 885 erofs_exit_sysfs(); 886 sysfs_err: 887 z_erofs_exit_subsystem(); 888 zip_err: 889 erofs_exit_shrinker(); 890 shrinker_err: 891 kmem_cache_destroy(erofs_inode_cachep); 892 return err; 893 } 894 895 static void __exit erofs_module_exit(void) 896 { 897 unregister_filesystem(&erofs_fs_type); 898 899 /* Ensure all RCU free inodes / pclusters are safe to be destroyed. */ 900 rcu_barrier(); 901 902 erofs_exit_sysfs(); 903 z_erofs_exit_subsystem(); 904 erofs_exit_shrinker(); 905 kmem_cache_destroy(erofs_inode_cachep); 906 } 907 908 static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf) 909 { 910 struct super_block *sb = dentry->d_sb; 911 struct erofs_sb_info *sbi = EROFS_SB(sb); 912 913 buf->f_type = sb->s_magic; 914 buf->f_bsize = sb->s_blocksize; 915 buf->f_blocks = sbi->total_blocks; 916 buf->f_bfree = buf->f_bavail = 0; 917 buf->f_files = ULLONG_MAX; 918 buf->f_ffree = ULLONG_MAX - sbi->inos; 919 buf->f_namelen = EROFS_NAME_LEN; 920 921 if (uuid_is_null(&sb->s_uuid)) 922 buf->f_fsid = u64_to_fsid(!sb->s_bdev ? 0 : 923 huge_encode_dev(sb->s_bdev->bd_dev)); 924 else 925 buf->f_fsid = uuid_to_fsid(sb->s_uuid.b); 926 return 0; 927 } 928 929 static int erofs_show_options(struct seq_file *seq, struct dentry *root) 930 { 931 struct erofs_sb_info *sbi = EROFS_SB(root->d_sb); 932 struct erofs_mount_opts *opt = &sbi->opt; 933 934 if (IS_ENABLED(CONFIG_EROFS_FS_XATTR)) 935 seq_puts(seq, test_opt(opt, XATTR_USER) ? 936 ",user_xattr" : ",nouser_xattr"); 937 if (IS_ENABLED(CONFIG_EROFS_FS_POSIX_ACL)) 938 seq_puts(seq, test_opt(opt, POSIX_ACL) ? ",acl" : ",noacl"); 939 if (IS_ENABLED(CONFIG_EROFS_FS_ZIP)) 940 seq_printf(seq, ",cache_strategy=%s", 941 erofs_param_cache_strategy[opt->cache_strategy].name); 942 if (test_opt(opt, DAX_ALWAYS)) 943 seq_puts(seq, ",dax=always"); 944 if (test_opt(opt, DAX_NEVER)) 945 seq_puts(seq, ",dax=never"); 946 if (erofs_is_fileio_mode(sbi) && test_opt(opt, DIRECT_IO)) 947 seq_puts(seq, ",directio"); 948 #ifdef CONFIG_EROFS_FS_ONDEMAND 949 if (sbi->fsid) 950 seq_printf(seq, ",fsid=%s", sbi->fsid); 951 if (sbi->domain_id) 952 seq_printf(seq, ",domain_id=%s", sbi->domain_id); 953 #endif 954 return 0; 955 } 956 957 const struct super_operations erofs_sops = { 958 .put_super = erofs_put_super, 959 .alloc_inode = erofs_alloc_inode, 960 .free_inode = erofs_free_inode, 961 .statfs = erofs_statfs, 962 .show_options = erofs_show_options, 963 }; 964 965 module_init(erofs_module_init); 966 module_exit(erofs_module_exit); 967 968 MODULE_DESCRIPTION("Enhanced ROM File System"); 969 MODULE_AUTHOR("Gao Xiang, Chao Yu, Miao Xie, CONSUMER BG, HUAWEI Inc."); 970 MODULE_LICENSE("GPL"); 971