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 "xattr.h" 14 15 #define CREATE_TRACE_POINTS 16 #include <trace/events/erofs.h> 17 18 static struct kmem_cache *erofs_inode_cachep __read_mostly; 19 20 void _erofs_err(struct super_block *sb, const char *func, const char *fmt, ...) 21 { 22 struct va_format vaf; 23 va_list args; 24 25 va_start(args, fmt); 26 27 vaf.fmt = fmt; 28 vaf.va = &args; 29 30 if (sb) 31 pr_err("(device %s): %s: %pV", sb->s_id, func, &vaf); 32 else 33 pr_err("%s: %pV", func, &vaf); 34 va_end(args); 35 } 36 37 void _erofs_info(struct super_block *sb, const char *func, const char *fmt, ...) 38 { 39 struct va_format vaf; 40 va_list args; 41 42 va_start(args, fmt); 43 44 vaf.fmt = fmt; 45 vaf.va = &args; 46 47 if (sb) 48 pr_info("(device %s): %pV", sb->s_id, &vaf); 49 else 50 pr_info("%pV", &vaf); 51 va_end(args); 52 } 53 54 static int erofs_superblock_csum_verify(struct super_block *sb, void *sbdata) 55 { 56 size_t len = 1 << EROFS_SB(sb)->blkszbits; 57 struct erofs_super_block *dsb; 58 u32 expected_crc, crc; 59 60 if (len > EROFS_SUPER_OFFSET) 61 len -= EROFS_SUPER_OFFSET; 62 63 dsb = kmemdup(sbdata + EROFS_SUPER_OFFSET, len, GFP_KERNEL); 64 if (!dsb) 65 return -ENOMEM; 66 67 expected_crc = le32_to_cpu(dsb->checksum); 68 dsb->checksum = 0; 69 /* to allow for x86 boot sectors and other oddities. */ 70 crc = crc32c(~0, dsb, len); 71 kfree(dsb); 72 73 if (crc != expected_crc) { 74 erofs_err(sb, "invalid checksum 0x%08x, 0x%08x expected", 75 crc, expected_crc); 76 return -EBADMSG; 77 } 78 return 0; 79 } 80 81 static void erofs_inode_init_once(void *ptr) 82 { 83 struct erofs_inode *vi = ptr; 84 85 inode_init_once(&vi->vfs_inode); 86 } 87 88 static struct inode *erofs_alloc_inode(struct super_block *sb) 89 { 90 struct erofs_inode *vi = 91 alloc_inode_sb(sb, erofs_inode_cachep, GFP_KERNEL); 92 93 if (!vi) 94 return NULL; 95 96 /* zero out everything except vfs_inode */ 97 memset(vi, 0, offsetof(struct erofs_inode, vfs_inode)); 98 return &vi->vfs_inode; 99 } 100 101 static void erofs_free_inode(struct inode *inode) 102 { 103 struct erofs_inode *vi = EROFS_I(inode); 104 105 if (inode->i_op == &erofs_fast_symlink_iops) 106 kfree(inode->i_link); 107 kfree(vi->xattr_shared_xattrs); 108 kmem_cache_free(erofs_inode_cachep, vi); 109 } 110 111 static bool check_layout_compatibility(struct super_block *sb, 112 struct erofs_super_block *dsb) 113 { 114 const unsigned int feature = le32_to_cpu(dsb->feature_incompat); 115 116 EROFS_SB(sb)->feature_incompat = feature; 117 118 /* check if current kernel meets all mandatory requirements */ 119 if (feature & (~EROFS_ALL_FEATURE_INCOMPAT)) { 120 erofs_err(sb, "unidentified incompatible feature %x, please upgrade kernel", 121 feature & ~EROFS_ALL_FEATURE_INCOMPAT); 122 return false; 123 } 124 return true; 125 } 126 127 /* read variable-sized metadata, offset will be aligned by 4-byte */ 128 void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf, 129 erofs_off_t *offset, int *lengthp) 130 { 131 u8 *buffer, *ptr; 132 int len, i, cnt; 133 134 *offset = round_up(*offset, 4); 135 ptr = erofs_bread(buf, erofs_blknr(sb, *offset), EROFS_KMAP); 136 if (IS_ERR(ptr)) 137 return ptr; 138 139 len = le16_to_cpu(*(__le16 *)&ptr[erofs_blkoff(sb, *offset)]); 140 if (!len) 141 len = U16_MAX + 1; 142 buffer = kmalloc(len, GFP_KERNEL); 143 if (!buffer) 144 return ERR_PTR(-ENOMEM); 145 *offset += sizeof(__le16); 146 *lengthp = len; 147 148 for (i = 0; i < len; i += cnt) { 149 cnt = min_t(int, sb->s_blocksize - erofs_blkoff(sb, *offset), 150 len - i); 151 ptr = erofs_bread(buf, erofs_blknr(sb, *offset), EROFS_KMAP); 152 if (IS_ERR(ptr)) { 153 kfree(buffer); 154 return ptr; 155 } 156 memcpy(buffer + i, ptr + erofs_blkoff(sb, *offset), cnt); 157 *offset += cnt; 158 } 159 return buffer; 160 } 161 162 #ifndef CONFIG_EROFS_FS_ZIP 163 static int z_erofs_parse_cfgs(struct super_block *sb, 164 struct erofs_super_block *dsb) 165 { 166 if (!dsb->u1.available_compr_algs) 167 return 0; 168 169 erofs_err(sb, "compression disabled, unable to mount compressed EROFS"); 170 return -EOPNOTSUPP; 171 } 172 #endif 173 174 static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb, 175 struct erofs_device_info *dif, erofs_off_t *pos) 176 { 177 struct erofs_sb_info *sbi = EROFS_SB(sb); 178 struct erofs_fscache *fscache; 179 struct erofs_deviceslot *dis; 180 struct file *bdev_file; 181 void *ptr; 182 183 ptr = erofs_read_metabuf(buf, sb, erofs_blknr(sb, *pos), EROFS_KMAP); 184 if (IS_ERR(ptr)) 185 return PTR_ERR(ptr); 186 dis = ptr + erofs_blkoff(sb, *pos); 187 188 if (!sbi->devs->flatdev && !dif->path) { 189 if (!dis->tag[0]) { 190 erofs_err(sb, "empty device tag @ pos %llu", *pos); 191 return -EINVAL; 192 } 193 dif->path = kmemdup_nul(dis->tag, sizeof(dis->tag), GFP_KERNEL); 194 if (!dif->path) 195 return -ENOMEM; 196 } 197 198 if (erofs_is_fscache_mode(sb)) { 199 fscache = erofs_fscache_register_cookie(sb, dif->path, 0); 200 if (IS_ERR(fscache)) 201 return PTR_ERR(fscache); 202 dif->fscache = fscache; 203 } else if (!sbi->devs->flatdev) { 204 bdev_file = bdev_file_open_by_path(dif->path, BLK_OPEN_READ, 205 sb->s_type, NULL); 206 if (IS_ERR(bdev_file)) 207 return PTR_ERR(bdev_file); 208 dif->bdev_file = bdev_file; 209 dif->dax_dev = fs_dax_get_by_bdev(file_bdev(bdev_file), 210 &dif->dax_part_off, NULL, NULL); 211 } 212 213 dif->blocks = le32_to_cpu(dis->blocks); 214 dif->mapped_blkaddr = le32_to_cpu(dis->mapped_blkaddr); 215 sbi->total_blocks += dif->blocks; 216 *pos += EROFS_DEVT_SLOT_SIZE; 217 return 0; 218 } 219 220 static int erofs_scan_devices(struct super_block *sb, 221 struct erofs_super_block *dsb) 222 { 223 struct erofs_sb_info *sbi = EROFS_SB(sb); 224 unsigned int ondisk_extradevs; 225 erofs_off_t pos; 226 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 227 struct erofs_device_info *dif; 228 int id, err = 0; 229 230 sbi->total_blocks = sbi->primarydevice_blocks; 231 if (!erofs_sb_has_device_table(sbi)) 232 ondisk_extradevs = 0; 233 else 234 ondisk_extradevs = le16_to_cpu(dsb->extra_devices); 235 236 if (sbi->devs->extra_devices && 237 ondisk_extradevs != sbi->devs->extra_devices) { 238 erofs_err(sb, "extra devices don't match (ondisk %u, given %u)", 239 ondisk_extradevs, sbi->devs->extra_devices); 240 return -EINVAL; 241 } 242 if (!ondisk_extradevs) 243 return 0; 244 245 if (!sbi->devs->extra_devices && !erofs_is_fscache_mode(sb)) 246 sbi->devs->flatdev = true; 247 248 sbi->device_id_mask = roundup_pow_of_two(ondisk_extradevs + 1) - 1; 249 pos = le16_to_cpu(dsb->devt_slotoff) * EROFS_DEVT_SLOT_SIZE; 250 down_read(&sbi->devs->rwsem); 251 if (sbi->devs->extra_devices) { 252 idr_for_each_entry(&sbi->devs->tree, dif, id) { 253 err = erofs_init_device(&buf, sb, dif, &pos); 254 if (err) 255 break; 256 } 257 } else { 258 for (id = 0; id < ondisk_extradevs; id++) { 259 dif = kzalloc(sizeof(*dif), GFP_KERNEL); 260 if (!dif) { 261 err = -ENOMEM; 262 break; 263 } 264 265 err = idr_alloc(&sbi->devs->tree, dif, 0, 0, GFP_KERNEL); 266 if (err < 0) { 267 kfree(dif); 268 break; 269 } 270 ++sbi->devs->extra_devices; 271 272 err = erofs_init_device(&buf, sb, dif, &pos); 273 if (err) 274 break; 275 } 276 } 277 up_read(&sbi->devs->rwsem); 278 erofs_put_metabuf(&buf); 279 return err; 280 } 281 282 static int erofs_read_superblock(struct super_block *sb) 283 { 284 struct erofs_sb_info *sbi; 285 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 286 struct erofs_super_block *dsb; 287 void *data; 288 int ret; 289 290 data = erofs_read_metabuf(&buf, sb, 0, EROFS_KMAP); 291 if (IS_ERR(data)) { 292 erofs_err(sb, "cannot read erofs superblock"); 293 return PTR_ERR(data); 294 } 295 296 sbi = EROFS_SB(sb); 297 dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET); 298 299 ret = -EINVAL; 300 if (le32_to_cpu(dsb->magic) != EROFS_SUPER_MAGIC_V1) { 301 erofs_err(sb, "cannot find valid erofs superblock"); 302 goto out; 303 } 304 305 sbi->blkszbits = dsb->blkszbits; 306 if (sbi->blkszbits < 9 || sbi->blkszbits > PAGE_SHIFT) { 307 erofs_err(sb, "blkszbits %u isn't supported", sbi->blkszbits); 308 goto out; 309 } 310 if (dsb->dirblkbits) { 311 erofs_err(sb, "dirblkbits %u isn't supported", dsb->dirblkbits); 312 goto out; 313 } 314 315 sbi->feature_compat = le32_to_cpu(dsb->feature_compat); 316 if (erofs_sb_has_sb_chksum(sbi)) { 317 ret = erofs_superblock_csum_verify(sb, data); 318 if (ret) 319 goto out; 320 } 321 322 ret = -EINVAL; 323 if (!check_layout_compatibility(sb, dsb)) 324 goto out; 325 326 sbi->sb_size = 128 + dsb->sb_extslots * EROFS_SB_EXTSLOT_SIZE; 327 if (sbi->sb_size > PAGE_SIZE - EROFS_SUPER_OFFSET) { 328 erofs_err(sb, "invalid sb_extslots %u (more than a fs block)", 329 sbi->sb_size); 330 goto out; 331 } 332 sbi->primarydevice_blocks = le32_to_cpu(dsb->blocks); 333 sbi->meta_blkaddr = le32_to_cpu(dsb->meta_blkaddr); 334 #ifdef CONFIG_EROFS_FS_XATTR 335 sbi->xattr_blkaddr = le32_to_cpu(dsb->xattr_blkaddr); 336 sbi->xattr_prefix_start = le32_to_cpu(dsb->xattr_prefix_start); 337 sbi->xattr_prefix_count = dsb->xattr_prefix_count; 338 sbi->xattr_filter_reserved = dsb->xattr_filter_reserved; 339 #endif 340 sbi->islotbits = ilog2(sizeof(struct erofs_inode_compact)); 341 sbi->root_nid = le16_to_cpu(dsb->root_nid); 342 sbi->packed_nid = le64_to_cpu(dsb->packed_nid); 343 sbi->inos = le64_to_cpu(dsb->inos); 344 345 sbi->build_time = le64_to_cpu(dsb->build_time); 346 sbi->build_time_nsec = le32_to_cpu(dsb->build_time_nsec); 347 348 memcpy(&sb->s_uuid, dsb->uuid, sizeof(dsb->uuid)); 349 350 ret = strscpy(sbi->volume_name, dsb->volume_name, 351 sizeof(dsb->volume_name)); 352 if (ret < 0) { /* -E2BIG */ 353 erofs_err(sb, "bad volume name without NIL terminator"); 354 ret = -EFSCORRUPTED; 355 goto out; 356 } 357 358 /* parse on-disk compression configurations */ 359 ret = z_erofs_parse_cfgs(sb, dsb); 360 if (ret < 0) 361 goto out; 362 363 /* handle multiple devices */ 364 ret = erofs_scan_devices(sb, dsb); 365 366 if (erofs_is_fscache_mode(sb)) 367 erofs_info(sb, "EXPERIMENTAL fscache-based on-demand read feature in use. Use at your own risk!"); 368 out: 369 erofs_put_metabuf(&buf); 370 return ret; 371 } 372 373 static void erofs_default_options(struct erofs_fs_context *ctx) 374 { 375 #ifdef CONFIG_EROFS_FS_ZIP 376 ctx->opt.cache_strategy = EROFS_ZIP_CACHE_READAROUND; 377 ctx->opt.max_sync_decompress_pages = 3; 378 ctx->opt.sync_decompress = EROFS_SYNC_DECOMPRESS_AUTO; 379 #endif 380 #ifdef CONFIG_EROFS_FS_XATTR 381 set_opt(&ctx->opt, XATTR_USER); 382 #endif 383 #ifdef CONFIG_EROFS_FS_POSIX_ACL 384 set_opt(&ctx->opt, POSIX_ACL); 385 #endif 386 } 387 388 enum { 389 Opt_user_xattr, 390 Opt_acl, 391 Opt_cache_strategy, 392 Opt_dax, 393 Opt_dax_enum, 394 Opt_device, 395 Opt_fsid, 396 Opt_domain_id, 397 Opt_err 398 }; 399 400 static const struct constant_table erofs_param_cache_strategy[] = { 401 {"disabled", EROFS_ZIP_CACHE_DISABLED}, 402 {"readahead", EROFS_ZIP_CACHE_READAHEAD}, 403 {"readaround", EROFS_ZIP_CACHE_READAROUND}, 404 {} 405 }; 406 407 static const struct constant_table erofs_dax_param_enums[] = { 408 {"always", EROFS_MOUNT_DAX_ALWAYS}, 409 {"never", EROFS_MOUNT_DAX_NEVER}, 410 {} 411 }; 412 413 static const struct fs_parameter_spec erofs_fs_parameters[] = { 414 fsparam_flag_no("user_xattr", Opt_user_xattr), 415 fsparam_flag_no("acl", Opt_acl), 416 fsparam_enum("cache_strategy", Opt_cache_strategy, 417 erofs_param_cache_strategy), 418 fsparam_flag("dax", Opt_dax), 419 fsparam_enum("dax", Opt_dax_enum, erofs_dax_param_enums), 420 fsparam_string("device", Opt_device), 421 fsparam_string("fsid", Opt_fsid), 422 fsparam_string("domain_id", Opt_domain_id), 423 {} 424 }; 425 426 static bool erofs_fc_set_dax_mode(struct fs_context *fc, unsigned int mode) 427 { 428 #ifdef CONFIG_FS_DAX 429 struct erofs_fs_context *ctx = fc->fs_private; 430 431 switch (mode) { 432 case EROFS_MOUNT_DAX_ALWAYS: 433 set_opt(&ctx->opt, DAX_ALWAYS); 434 clear_opt(&ctx->opt, DAX_NEVER); 435 return true; 436 case EROFS_MOUNT_DAX_NEVER: 437 set_opt(&ctx->opt, DAX_NEVER); 438 clear_opt(&ctx->opt, DAX_ALWAYS); 439 return true; 440 default: 441 DBG_BUGON(1); 442 return false; 443 } 444 #else 445 errorfc(fc, "dax options not supported"); 446 return false; 447 #endif 448 } 449 450 static int erofs_fc_parse_param(struct fs_context *fc, 451 struct fs_parameter *param) 452 { 453 struct erofs_fs_context *ctx = fc->fs_private; 454 struct fs_parse_result result; 455 struct erofs_device_info *dif; 456 int opt, ret; 457 458 opt = fs_parse(fc, erofs_fs_parameters, param, &result); 459 if (opt < 0) 460 return opt; 461 462 switch (opt) { 463 case Opt_user_xattr: 464 #ifdef CONFIG_EROFS_FS_XATTR 465 if (result.boolean) 466 set_opt(&ctx->opt, XATTR_USER); 467 else 468 clear_opt(&ctx->opt, XATTR_USER); 469 #else 470 errorfc(fc, "{,no}user_xattr options not supported"); 471 #endif 472 break; 473 case Opt_acl: 474 #ifdef CONFIG_EROFS_FS_POSIX_ACL 475 if (result.boolean) 476 set_opt(&ctx->opt, POSIX_ACL); 477 else 478 clear_opt(&ctx->opt, POSIX_ACL); 479 #else 480 errorfc(fc, "{,no}acl options not supported"); 481 #endif 482 break; 483 case Opt_cache_strategy: 484 #ifdef CONFIG_EROFS_FS_ZIP 485 ctx->opt.cache_strategy = result.uint_32; 486 #else 487 errorfc(fc, "compression not supported, cache_strategy ignored"); 488 #endif 489 break; 490 case Opt_dax: 491 if (!erofs_fc_set_dax_mode(fc, EROFS_MOUNT_DAX_ALWAYS)) 492 return -EINVAL; 493 break; 494 case Opt_dax_enum: 495 if (!erofs_fc_set_dax_mode(fc, result.uint_32)) 496 return -EINVAL; 497 break; 498 case Opt_device: 499 dif = kzalloc(sizeof(*dif), GFP_KERNEL); 500 if (!dif) 501 return -ENOMEM; 502 dif->path = kstrdup(param->string, GFP_KERNEL); 503 if (!dif->path) { 504 kfree(dif); 505 return -ENOMEM; 506 } 507 down_write(&ctx->devs->rwsem); 508 ret = idr_alloc(&ctx->devs->tree, dif, 0, 0, GFP_KERNEL); 509 up_write(&ctx->devs->rwsem); 510 if (ret < 0) { 511 kfree(dif->path); 512 kfree(dif); 513 return ret; 514 } 515 ++ctx->devs->extra_devices; 516 break; 517 #ifdef CONFIG_EROFS_FS_ONDEMAND 518 case Opt_fsid: 519 kfree(ctx->fsid); 520 ctx->fsid = kstrdup(param->string, GFP_KERNEL); 521 if (!ctx->fsid) 522 return -ENOMEM; 523 break; 524 case Opt_domain_id: 525 kfree(ctx->domain_id); 526 ctx->domain_id = kstrdup(param->string, GFP_KERNEL); 527 if (!ctx->domain_id) 528 return -ENOMEM; 529 break; 530 #else 531 case Opt_fsid: 532 case Opt_domain_id: 533 errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name); 534 break; 535 #endif 536 default: 537 return -ENOPARAM; 538 } 539 return 0; 540 } 541 542 static struct inode *erofs_nfs_get_inode(struct super_block *sb, 543 u64 ino, u32 generation) 544 { 545 return erofs_iget(sb, ino); 546 } 547 548 static struct dentry *erofs_fh_to_dentry(struct super_block *sb, 549 struct fid *fid, int fh_len, int fh_type) 550 { 551 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 552 erofs_nfs_get_inode); 553 } 554 555 static struct dentry *erofs_fh_to_parent(struct super_block *sb, 556 struct fid *fid, int fh_len, int fh_type) 557 { 558 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 559 erofs_nfs_get_inode); 560 } 561 562 static struct dentry *erofs_get_parent(struct dentry *child) 563 { 564 erofs_nid_t nid; 565 unsigned int d_type; 566 int err; 567 568 err = erofs_namei(d_inode(child), &dotdot_name, &nid, &d_type); 569 if (err) 570 return ERR_PTR(err); 571 return d_obtain_alias(erofs_iget(child->d_sb, nid)); 572 } 573 574 static const struct export_operations erofs_export_ops = { 575 .encode_fh = generic_encode_ino32_fh, 576 .fh_to_dentry = erofs_fh_to_dentry, 577 .fh_to_parent = erofs_fh_to_parent, 578 .get_parent = erofs_get_parent, 579 }; 580 581 static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) 582 { 583 struct inode *inode; 584 struct erofs_sb_info *sbi; 585 struct erofs_fs_context *ctx = fc->fs_private; 586 int err; 587 588 sb->s_magic = EROFS_SUPER_MAGIC; 589 sb->s_flags |= SB_RDONLY | SB_NOATIME; 590 sb->s_maxbytes = MAX_LFS_FILESIZE; 591 sb->s_op = &erofs_sops; 592 593 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 594 if (!sbi) 595 return -ENOMEM; 596 597 sb->s_fs_info = sbi; 598 sbi->opt = ctx->opt; 599 sbi->devs = ctx->devs; 600 ctx->devs = NULL; 601 sbi->fsid = ctx->fsid; 602 ctx->fsid = NULL; 603 sbi->domain_id = ctx->domain_id; 604 ctx->domain_id = NULL; 605 606 sbi->blkszbits = PAGE_SHIFT; 607 if (erofs_is_fscache_mode(sb)) { 608 sb->s_blocksize = PAGE_SIZE; 609 sb->s_blocksize_bits = PAGE_SHIFT; 610 611 err = erofs_fscache_register_fs(sb); 612 if (err) 613 return err; 614 615 err = super_setup_bdi(sb); 616 if (err) 617 return err; 618 } else { 619 if (!sb_set_blocksize(sb, PAGE_SIZE)) { 620 errorfc(fc, "failed to set initial blksize"); 621 return -EINVAL; 622 } 623 624 sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev, 625 &sbi->dax_part_off, 626 NULL, NULL); 627 } 628 629 err = erofs_read_superblock(sb); 630 if (err) 631 return err; 632 633 if (sb->s_blocksize_bits != sbi->blkszbits) { 634 if (erofs_is_fscache_mode(sb)) { 635 errorfc(fc, "unsupported blksize for fscache mode"); 636 return -EINVAL; 637 } 638 if (!sb_set_blocksize(sb, 1 << sbi->blkszbits)) { 639 errorfc(fc, "failed to set erofs blksize"); 640 return -EINVAL; 641 } 642 } 643 644 if (test_opt(&sbi->opt, DAX_ALWAYS)) { 645 if (!sbi->dax_dev) { 646 errorfc(fc, "DAX unsupported by block device. Turning off DAX."); 647 clear_opt(&sbi->opt, DAX_ALWAYS); 648 } else if (sbi->blkszbits != PAGE_SHIFT) { 649 errorfc(fc, "unsupported blocksize for DAX"); 650 clear_opt(&sbi->opt, DAX_ALWAYS); 651 } 652 } 653 654 sb->s_time_gran = 1; 655 sb->s_xattr = erofs_xattr_handlers; 656 sb->s_export_op = &erofs_export_ops; 657 658 if (test_opt(&sbi->opt, POSIX_ACL)) 659 sb->s_flags |= SB_POSIXACL; 660 else 661 sb->s_flags &= ~SB_POSIXACL; 662 663 #ifdef CONFIG_EROFS_FS_ZIP 664 xa_init(&sbi->managed_pslots); 665 #endif 666 667 inode = erofs_iget(sb, sbi->root_nid); 668 if (IS_ERR(inode)) 669 return PTR_ERR(inode); 670 671 if (!S_ISDIR(inode->i_mode)) { 672 erofs_err(sb, "rootino(nid %llu) is not a directory(i_mode %o)", 673 sbi->root_nid, inode->i_mode); 674 iput(inode); 675 return -EINVAL; 676 } 677 678 sb->s_root = d_make_root(inode); 679 if (!sb->s_root) 680 return -ENOMEM; 681 682 erofs_shrinker_register(sb); 683 if (erofs_sb_has_fragments(sbi) && sbi->packed_nid) { 684 sbi->packed_inode = erofs_iget(sb, sbi->packed_nid); 685 if (IS_ERR(sbi->packed_inode)) { 686 err = PTR_ERR(sbi->packed_inode); 687 sbi->packed_inode = NULL; 688 return err; 689 } 690 } 691 err = erofs_init_managed_cache(sb); 692 if (err) 693 return err; 694 695 err = erofs_xattr_prefixes_init(sb); 696 if (err) 697 return err; 698 699 err = erofs_register_sysfs(sb); 700 if (err) 701 return err; 702 703 erofs_info(sb, "mounted with root inode @ nid %llu.", sbi->root_nid); 704 return 0; 705 } 706 707 static int erofs_fc_get_tree(struct fs_context *fc) 708 { 709 struct erofs_fs_context *ctx = fc->fs_private; 710 711 if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && ctx->fsid) 712 return get_tree_nodev(fc, erofs_fc_fill_super); 713 714 return get_tree_bdev(fc, erofs_fc_fill_super); 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_fs_context *ctx = fc->fs_private; 722 723 DBG_BUGON(!sb_rdonly(sb)); 724 725 if (ctx->fsid || ctx->domain_id) 726 erofs_info(sb, "ignoring reconfiguration for fsid|domain_id."); 727 728 if (test_opt(&ctx->opt, POSIX_ACL)) 729 fc->sb_flags |= SB_POSIXACL; 730 else 731 fc->sb_flags &= ~SB_POSIXACL; 732 733 sbi->opt = ctx->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->bdev_file) 745 fput(dif->bdev_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_fc_free(struct fs_context *fc) 763 { 764 struct erofs_fs_context *ctx = fc->fs_private; 765 766 erofs_free_dev_context(ctx->devs); 767 kfree(ctx->fsid); 768 kfree(ctx->domain_id); 769 kfree(ctx); 770 } 771 772 static const struct fs_context_operations erofs_context_ops = { 773 .parse_param = erofs_fc_parse_param, 774 .get_tree = erofs_fc_get_tree, 775 .reconfigure = erofs_fc_reconfigure, 776 .free = erofs_fc_free, 777 }; 778 779 static int erofs_init_fs_context(struct fs_context *fc) 780 { 781 struct erofs_fs_context *ctx; 782 783 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 784 if (!ctx) 785 return -ENOMEM; 786 ctx->devs = kzalloc(sizeof(struct erofs_dev_context), GFP_KERNEL); 787 if (!ctx->devs) { 788 kfree(ctx); 789 return -ENOMEM; 790 } 791 fc->fs_private = ctx; 792 793 idr_init(&ctx->devs->tree); 794 init_rwsem(&ctx->devs->rwsem); 795 erofs_default_options(ctx); 796 fc->ops = &erofs_context_ops; 797 return 0; 798 } 799 800 static void erofs_kill_sb(struct super_block *sb) 801 { 802 struct erofs_sb_info *sbi; 803 804 if (erofs_is_fscache_mode(sb)) 805 kill_anon_super(sb); 806 else 807 kill_block_super(sb); 808 809 sbi = EROFS_SB(sb); 810 if (!sbi) 811 return; 812 813 erofs_free_dev_context(sbi->devs); 814 fs_put_dax(sbi->dax_dev, NULL); 815 erofs_fscache_unregister_fs(sb); 816 kfree(sbi->fsid); 817 kfree(sbi->domain_id); 818 kfree(sbi); 819 sb->s_fs_info = NULL; 820 } 821 822 static void erofs_put_super(struct super_block *sb) 823 { 824 struct erofs_sb_info *const sbi = EROFS_SB(sb); 825 826 DBG_BUGON(!sbi); 827 828 erofs_unregister_sysfs(sb); 829 erofs_shrinker_unregister(sb); 830 erofs_xattr_prefixes_cleanup(sb); 831 #ifdef CONFIG_EROFS_FS_ZIP 832 iput(sbi->managed_cache); 833 sbi->managed_cache = NULL; 834 #endif 835 iput(sbi->packed_inode); 836 sbi->packed_inode = NULL; 837 erofs_free_dev_context(sbi->devs); 838 sbi->devs = NULL; 839 erofs_fscache_unregister_fs(sb); 840 } 841 842 static struct file_system_type erofs_fs_type = { 843 .owner = THIS_MODULE, 844 .name = "erofs", 845 .init_fs_context = erofs_init_fs_context, 846 .kill_sb = erofs_kill_sb, 847 .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, 848 }; 849 MODULE_ALIAS_FS("erofs"); 850 851 static int __init erofs_module_init(void) 852 { 853 int err; 854 855 erofs_check_ondisk_layout_definitions(); 856 857 erofs_inode_cachep = kmem_cache_create("erofs_inode", 858 sizeof(struct erofs_inode), 0, 859 SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT, 860 erofs_inode_init_once); 861 if (!erofs_inode_cachep) 862 return -ENOMEM; 863 864 err = erofs_init_shrinker(); 865 if (err) 866 goto shrinker_err; 867 868 err = z_erofs_lzma_init(); 869 if (err) 870 goto lzma_err; 871 872 err = z_erofs_deflate_init(); 873 if (err) 874 goto deflate_err; 875 876 erofs_pcpubuf_init(); 877 err = z_erofs_init_zip_subsystem(); 878 if (err) 879 goto zip_err; 880 881 err = erofs_init_sysfs(); 882 if (err) 883 goto sysfs_err; 884 885 err = register_filesystem(&erofs_fs_type); 886 if (err) 887 goto fs_err; 888 889 return 0; 890 891 fs_err: 892 erofs_exit_sysfs(); 893 sysfs_err: 894 z_erofs_exit_zip_subsystem(); 895 zip_err: 896 z_erofs_deflate_exit(); 897 deflate_err: 898 z_erofs_lzma_exit(); 899 lzma_err: 900 erofs_exit_shrinker(); 901 shrinker_err: 902 kmem_cache_destroy(erofs_inode_cachep); 903 return err; 904 } 905 906 static void __exit erofs_module_exit(void) 907 { 908 unregister_filesystem(&erofs_fs_type); 909 910 /* Ensure all RCU free inodes / pclusters are safe to be destroyed. */ 911 rcu_barrier(); 912 913 erofs_exit_sysfs(); 914 z_erofs_exit_zip_subsystem(); 915 z_erofs_deflate_exit(); 916 z_erofs_lzma_exit(); 917 erofs_exit_shrinker(); 918 kmem_cache_destroy(erofs_inode_cachep); 919 erofs_pcpubuf_exit(); 920 } 921 922 static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf) 923 { 924 struct super_block *sb = dentry->d_sb; 925 struct erofs_sb_info *sbi = EROFS_SB(sb); 926 u64 id = 0; 927 928 if (!erofs_is_fscache_mode(sb)) 929 id = huge_encode_dev(sb->s_bdev->bd_dev); 930 931 buf->f_type = sb->s_magic; 932 buf->f_bsize = sb->s_blocksize; 933 buf->f_blocks = sbi->total_blocks; 934 buf->f_bfree = buf->f_bavail = 0; 935 936 buf->f_files = ULLONG_MAX; 937 buf->f_ffree = ULLONG_MAX - sbi->inos; 938 939 buf->f_namelen = EROFS_NAME_LEN; 940 941 buf->f_fsid = u64_to_fsid(id); 942 return 0; 943 } 944 945 static int erofs_show_options(struct seq_file *seq, struct dentry *root) 946 { 947 struct erofs_sb_info *sbi = EROFS_SB(root->d_sb); 948 struct erofs_mount_opts *opt = &sbi->opt; 949 950 #ifdef CONFIG_EROFS_FS_XATTR 951 if (test_opt(opt, XATTR_USER)) 952 seq_puts(seq, ",user_xattr"); 953 else 954 seq_puts(seq, ",nouser_xattr"); 955 #endif 956 #ifdef CONFIG_EROFS_FS_POSIX_ACL 957 if (test_opt(opt, POSIX_ACL)) 958 seq_puts(seq, ",acl"); 959 else 960 seq_puts(seq, ",noacl"); 961 #endif 962 #ifdef CONFIG_EROFS_FS_ZIP 963 if (opt->cache_strategy == EROFS_ZIP_CACHE_DISABLED) 964 seq_puts(seq, ",cache_strategy=disabled"); 965 else if (opt->cache_strategy == EROFS_ZIP_CACHE_READAHEAD) 966 seq_puts(seq, ",cache_strategy=readahead"); 967 else if (opt->cache_strategy == EROFS_ZIP_CACHE_READAROUND) 968 seq_puts(seq, ",cache_strategy=readaround"); 969 #endif 970 if (test_opt(opt, DAX_ALWAYS)) 971 seq_puts(seq, ",dax=always"); 972 if (test_opt(opt, DAX_NEVER)) 973 seq_puts(seq, ",dax=never"); 974 #ifdef CONFIG_EROFS_FS_ONDEMAND 975 if (sbi->fsid) 976 seq_printf(seq, ",fsid=%s", sbi->fsid); 977 if (sbi->domain_id) 978 seq_printf(seq, ",domain_id=%s", sbi->domain_id); 979 #endif 980 return 0; 981 } 982 983 const struct super_operations erofs_sops = { 984 .put_super = erofs_put_super, 985 .alloc_inode = erofs_alloc_inode, 986 .free_inode = erofs_free_inode, 987 .statfs = erofs_statfs, 988 .show_options = erofs_show_options, 989 }; 990 991 module_init(erofs_module_init); 992 module_exit(erofs_module_exit); 993 994 MODULE_DESCRIPTION("Enhanced ROM File System"); 995 MODULE_AUTHOR("Gao Xiang, Chao Yu, Miao Xie, CONSUMER BG, HUAWEI Inc."); 996 MODULE_LICENSE("GPL"); 997