984 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2017-2018 HUAWEI, Inc.4 * https://www.huawei.com/5 * Copyright (C) 2021, Alibaba Cloud6 */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_POINTS17#include <trace/events/erofs.h>18 19static struct kmem_cache *erofs_inode_cachep __read_mostly;20 21void _erofs_err(struct super_block *sb, const char *func, const char *fmt, ...)22{23 struct va_format vaf;24 va_list args;25 26 va_start(args, fmt);27 28 vaf.fmt = fmt;29 vaf.va = &args;30 31 if (sb)32 pr_err("(device %s): %s: %pV", sb->s_id, func, &vaf);33 else34 pr_err("%s: %pV", func, &vaf);35 va_end(args);36}37 38void _erofs_info(struct super_block *sb, const char *func, const char *fmt, ...)39{40 struct va_format vaf;41 va_list args;42 43 va_start(args, fmt);44 45 vaf.fmt = fmt;46 vaf.va = &args;47 48 if (sb)49 pr_info("(device %s): %pV", sb->s_id, &vaf);50 else51 pr_info("%pV", &vaf);52 va_end(args);53}54 55static int erofs_superblock_csum_verify(struct super_block *sb, void *sbdata)56{57 size_t len = 1 << EROFS_SB(sb)->blkszbits;58 struct erofs_super_block *dsb;59 u32 expected_crc, crc;60 61 if (len > EROFS_SUPER_OFFSET)62 len -= EROFS_SUPER_OFFSET;63 64 dsb = kmemdup(sbdata + EROFS_SUPER_OFFSET, len, GFP_KERNEL);65 if (!dsb)66 return -ENOMEM;67 68 expected_crc = le32_to_cpu(dsb->checksum);69 dsb->checksum = 0;70 /* to allow for x86 boot sectors and other oddities. */71 crc = crc32c(~0, dsb, len);72 kfree(dsb);73 74 if (crc != expected_crc) {75 erofs_err(sb, "invalid checksum 0x%08x, 0x%08x expected",76 crc, expected_crc);77 return -EBADMSG;78 }79 return 0;80}81 82static void erofs_inode_init_once(void *ptr)83{84 struct erofs_inode *vi = ptr;85 86 inode_init_once(&vi->vfs_inode);87}88 89static struct inode *erofs_alloc_inode(struct super_block *sb)90{91 struct erofs_inode *vi =92 alloc_inode_sb(sb, erofs_inode_cachep, GFP_KERNEL);93 94 if (!vi)95 return NULL;96 97 /* zero out everything except vfs_inode */98 memset(vi, 0, offsetof(struct erofs_inode, vfs_inode));99 return &vi->vfs_inode;100}101 102static void erofs_free_inode(struct inode *inode)103{104 struct erofs_inode *vi = EROFS_I(inode);105 106 if (inode->i_op == &erofs_fast_symlink_iops)107 kfree(inode->i_link);108 kfree(vi->xattr_shared_xattrs);109 kmem_cache_free(erofs_inode_cachep, vi);110}111 112/* read variable-sized metadata, offset will be aligned by 4-byte */113void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf,114 erofs_off_t *offset, int *lengthp)115{116 u8 *buffer, *ptr;117 int len, i, cnt;118 119 *offset = round_up(*offset, 4);120 ptr = erofs_bread(buf, *offset, EROFS_KMAP);121 if (IS_ERR(ptr))122 return ptr;123 124 len = le16_to_cpu(*(__le16 *)ptr);125 if (!len)126 len = U16_MAX + 1;127 buffer = kmalloc(len, GFP_KERNEL);128 if (!buffer)129 return ERR_PTR(-ENOMEM);130 *offset += sizeof(__le16);131 *lengthp = len;132 133 for (i = 0; i < len; i += cnt) {134 cnt = min_t(int, sb->s_blocksize - erofs_blkoff(sb, *offset),135 len - i);136 ptr = erofs_bread(buf, *offset, EROFS_KMAP);137 if (IS_ERR(ptr)) {138 kfree(buffer);139 return ptr;140 }141 memcpy(buffer + i, ptr, cnt);142 *offset += cnt;143 }144 return buffer;145}146 147#ifndef CONFIG_EROFS_FS_ZIP148static int z_erofs_parse_cfgs(struct super_block *sb,149 struct erofs_super_block *dsb)150{151 if (!dsb->u1.available_compr_algs)152 return 0;153 154 erofs_err(sb, "compression disabled, unable to mount compressed EROFS");155 return -EOPNOTSUPP;156}157#endif158 159static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb,160 struct erofs_device_info *dif, erofs_off_t *pos)161{162 struct erofs_sb_info *sbi = EROFS_SB(sb);163 struct erofs_fscache *fscache;164 struct erofs_deviceslot *dis;165 struct file *file;166 167 dis = erofs_read_metabuf(buf, sb, *pos, EROFS_KMAP);168 if (IS_ERR(dis))169 return PTR_ERR(dis);170 171 if (!sbi->devs->flatdev && !dif->path) {172 if (!dis->tag[0]) {173 erofs_err(sb, "empty device tag @ pos %llu", *pos);174 return -EINVAL;175 }176 dif->path = kmemdup_nul(dis->tag, sizeof(dis->tag), GFP_KERNEL);177 if (!dif->path)178 return -ENOMEM;179 }180 181 if (erofs_is_fscache_mode(sb)) {182 fscache = erofs_fscache_register_cookie(sb, dif->path, 0);183 if (IS_ERR(fscache))184 return PTR_ERR(fscache);185 dif->fscache = fscache;186 } else if (!sbi->devs->flatdev) {187 file = erofs_is_fileio_mode(sbi) ?188 filp_open(dif->path, O_RDONLY | O_LARGEFILE, 0) :189 bdev_file_open_by_path(dif->path,190 BLK_OPEN_READ, sb->s_type, NULL);191 if (IS_ERR(file))192 return PTR_ERR(file);193 194 if (!erofs_is_fileio_mode(sbi)) {195 dif->dax_dev = fs_dax_get_by_bdev(file_bdev(file),196 &dif->dax_part_off, NULL, NULL);197 } else if (!S_ISREG(file_inode(file)->i_mode)) {198 fput(file);199 return -EINVAL;200 }201 dif->file = file;202 }203 204 dif->blocks = le32_to_cpu(dis->blocks);205 dif->mapped_blkaddr = le32_to_cpu(dis->mapped_blkaddr);206 sbi->total_blocks += dif->blocks;207 *pos += EROFS_DEVT_SLOT_SIZE;208 return 0;209}210 211static int erofs_scan_devices(struct super_block *sb,212 struct erofs_super_block *dsb)213{214 struct erofs_sb_info *sbi = EROFS_SB(sb);215 unsigned int ondisk_extradevs;216 erofs_off_t pos;217 struct erofs_buf buf = __EROFS_BUF_INITIALIZER;218 struct erofs_device_info *dif;219 int id, err = 0;220 221 sbi->total_blocks = sbi->primarydevice_blocks;222 if (!erofs_sb_has_device_table(sbi))223 ondisk_extradevs = 0;224 else225 ondisk_extradevs = le16_to_cpu(dsb->extra_devices);226 227 if (sbi->devs->extra_devices &&228 ondisk_extradevs != sbi->devs->extra_devices) {229 erofs_err(sb, "extra devices don't match (ondisk %u, given %u)",230 ondisk_extradevs, sbi->devs->extra_devices);231 return -EINVAL;232 }233 if (!ondisk_extradevs)234 return 0;235 236 if (!sbi->devs->extra_devices && !erofs_is_fscache_mode(sb))237 sbi->devs->flatdev = true;238 239 sbi->device_id_mask = roundup_pow_of_two(ondisk_extradevs + 1) - 1;240 pos = le16_to_cpu(dsb->devt_slotoff) * EROFS_DEVT_SLOT_SIZE;241 down_read(&sbi->devs->rwsem);242 if (sbi->devs->extra_devices) {243 idr_for_each_entry(&sbi->devs->tree, dif, id) {244 err = erofs_init_device(&buf, sb, dif, &pos);245 if (err)246 break;247 }248 } else {249 for (id = 0; id < ondisk_extradevs; id++) {250 dif = kzalloc(sizeof(*dif), GFP_KERNEL);251 if (!dif) {252 err = -ENOMEM;253 break;254 }255 256 err = idr_alloc(&sbi->devs->tree, dif, 0, 0, GFP_KERNEL);257 if (err < 0) {258 kfree(dif);259 break;260 }261 ++sbi->devs->extra_devices;262 263 err = erofs_init_device(&buf, sb, dif, &pos);264 if (err)265 break;266 }267 }268 up_read(&sbi->devs->rwsem);269 erofs_put_metabuf(&buf);270 return err;271}272 273static int erofs_read_superblock(struct super_block *sb)274{275 struct erofs_sb_info *sbi = EROFS_SB(sb);276 struct erofs_buf buf = __EROFS_BUF_INITIALIZER;277 struct erofs_super_block *dsb;278 void *data;279 int ret;280 281 data = erofs_read_metabuf(&buf, sb, 0, EROFS_KMAP);282 if (IS_ERR(data)) {283 erofs_err(sb, "cannot read erofs superblock");284 return PTR_ERR(data);285 }286 287 dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET);288 ret = -EINVAL;289 if (le32_to_cpu(dsb->magic) != EROFS_SUPER_MAGIC_V1) {290 erofs_err(sb, "cannot find valid erofs superblock");291 goto out;292 }293 294 sbi->blkszbits = dsb->blkszbits;295 if (sbi->blkszbits < 9 || sbi->blkszbits > PAGE_SHIFT) {296 erofs_err(sb, "blkszbits %u isn't supported", sbi->blkszbits);297 goto out;298 }299 if (dsb->dirblkbits) {300 erofs_err(sb, "dirblkbits %u isn't supported", dsb->dirblkbits);301 goto out;302 }303 304 sbi->feature_compat = le32_to_cpu(dsb->feature_compat);305 if (erofs_sb_has_sb_chksum(sbi)) {306 ret = erofs_superblock_csum_verify(sb, data);307 if (ret)308 goto out;309 }310 311 ret = -EINVAL;312 sbi->feature_incompat = le32_to_cpu(dsb->feature_incompat);313 if (sbi->feature_incompat & ~EROFS_ALL_FEATURE_INCOMPAT) {314 erofs_err(sb, "unidentified incompatible feature %x, please upgrade kernel",315 sbi->feature_incompat & ~EROFS_ALL_FEATURE_INCOMPAT);316 goto out;317 }318 319 sbi->sb_size = 128 + dsb->sb_extslots * EROFS_SB_EXTSLOT_SIZE;320 if (sbi->sb_size > PAGE_SIZE - EROFS_SUPER_OFFSET) {321 erofs_err(sb, "invalid sb_extslots %u (more than a fs block)",322 sbi->sb_size);323 goto out;324 }325 sbi->primarydevice_blocks = le32_to_cpu(dsb->blocks);326 sbi->meta_blkaddr = le32_to_cpu(dsb->meta_blkaddr);327#ifdef CONFIG_EROFS_FS_XATTR328 sbi->xattr_blkaddr = le32_to_cpu(dsb->xattr_blkaddr);329 sbi->xattr_prefix_start = le32_to_cpu(dsb->xattr_prefix_start);330 sbi->xattr_prefix_count = dsb->xattr_prefix_count;331 sbi->xattr_filter_reserved = dsb->xattr_filter_reserved;332#endif333 sbi->islotbits = ilog2(sizeof(struct erofs_inode_compact));334 sbi->root_nid = le16_to_cpu(dsb->root_nid);335 sbi->packed_nid = le64_to_cpu(dsb->packed_nid);336 sbi->inos = le64_to_cpu(dsb->inos);337 338 sbi->build_time = le64_to_cpu(dsb->build_time);339 sbi->build_time_nsec = le32_to_cpu(dsb->build_time_nsec);340 341 super_set_uuid(sb, (void *)dsb->uuid, sizeof(dsb->uuid));342 343 ret = strscpy(sbi->volume_name, dsb->volume_name,344 sizeof(dsb->volume_name));345 if (ret < 0) { /* -E2BIG */346 erofs_err(sb, "bad volume name without NIL terminator");347 ret = -EFSCORRUPTED;348 goto out;349 }350 351 /* parse on-disk compression configurations */352 ret = z_erofs_parse_cfgs(sb, dsb);353 if (ret < 0)354 goto out;355 356 /* handle multiple devices */357 ret = erofs_scan_devices(sb, dsb);358 359 if (erofs_is_fscache_mode(sb))360 erofs_info(sb, "[deprecated] fscache-based on-demand read feature in use. Use at your own risk!");361out:362 erofs_put_metabuf(&buf);363 return ret;364}365 366static void erofs_default_options(struct erofs_sb_info *sbi)367{368#ifdef CONFIG_EROFS_FS_ZIP369 sbi->opt.cache_strategy = EROFS_ZIP_CACHE_READAROUND;370 sbi->opt.max_sync_decompress_pages = 3;371 sbi->opt.sync_decompress = EROFS_SYNC_DECOMPRESS_AUTO;372#endif373#ifdef CONFIG_EROFS_FS_XATTR374 set_opt(&sbi->opt, XATTR_USER);375#endif376#ifdef CONFIG_EROFS_FS_POSIX_ACL377 set_opt(&sbi->opt, POSIX_ACL);378#endif379}380 381enum {382 Opt_user_xattr,383 Opt_acl,384 Opt_cache_strategy,385 Opt_dax,386 Opt_dax_enum,387 Opt_device,388 Opt_fsid,389 Opt_domain_id,390 Opt_err391};392 393static const struct constant_table erofs_param_cache_strategy[] = {394 {"disabled", EROFS_ZIP_CACHE_DISABLED},395 {"readahead", EROFS_ZIP_CACHE_READAHEAD},396 {"readaround", EROFS_ZIP_CACHE_READAROUND},397 {}398};399 400static const struct constant_table erofs_dax_param_enums[] = {401 {"always", EROFS_MOUNT_DAX_ALWAYS},402 {"never", EROFS_MOUNT_DAX_NEVER},403 {}404};405 406static const struct fs_parameter_spec erofs_fs_parameters[] = {407 fsparam_flag_no("user_xattr", Opt_user_xattr),408 fsparam_flag_no("acl", Opt_acl),409 fsparam_enum("cache_strategy", Opt_cache_strategy,410 erofs_param_cache_strategy),411 fsparam_flag("dax", Opt_dax),412 fsparam_enum("dax", Opt_dax_enum, erofs_dax_param_enums),413 fsparam_string("device", Opt_device),414 fsparam_string("fsid", Opt_fsid),415 fsparam_string("domain_id", Opt_domain_id),416 {}417};418 419static bool erofs_fc_set_dax_mode(struct fs_context *fc, unsigned int mode)420{421#ifdef CONFIG_FS_DAX422 struct erofs_sb_info *sbi = fc->s_fs_info;423 424 switch (mode) {425 case EROFS_MOUNT_DAX_ALWAYS:426 set_opt(&sbi->opt, DAX_ALWAYS);427 clear_opt(&sbi->opt, DAX_NEVER);428 return true;429 case EROFS_MOUNT_DAX_NEVER:430 set_opt(&sbi->opt, DAX_NEVER);431 clear_opt(&sbi->opt, DAX_ALWAYS);432 return true;433 default:434 DBG_BUGON(1);435 return false;436 }437#else438 errorfc(fc, "dax options not supported");439 return false;440#endif441}442 443static int erofs_fc_parse_param(struct fs_context *fc,444 struct fs_parameter *param)445{446 struct erofs_sb_info *sbi = fc->s_fs_info;447 struct fs_parse_result result;448 struct erofs_device_info *dif;449 int opt, ret;450 451 opt = fs_parse(fc, erofs_fs_parameters, param, &result);452 if (opt < 0)453 return opt;454 455 switch (opt) {456 case Opt_user_xattr:457#ifdef CONFIG_EROFS_FS_XATTR458 if (result.boolean)459 set_opt(&sbi->opt, XATTR_USER);460 else461 clear_opt(&sbi->opt, XATTR_USER);462#else463 errorfc(fc, "{,no}user_xattr options not supported");464#endif465 break;466 case Opt_acl:467#ifdef CONFIG_EROFS_FS_POSIX_ACL468 if (result.boolean)469 set_opt(&sbi->opt, POSIX_ACL);470 else471 clear_opt(&sbi->opt, POSIX_ACL);472#else473 errorfc(fc, "{,no}acl options not supported");474#endif475 break;476 case Opt_cache_strategy:477#ifdef CONFIG_EROFS_FS_ZIP478 sbi->opt.cache_strategy = result.uint_32;479#else480 errorfc(fc, "compression not supported, cache_strategy ignored");481#endif482 break;483 case Opt_dax:484 if (!erofs_fc_set_dax_mode(fc, EROFS_MOUNT_DAX_ALWAYS))485 return -EINVAL;486 break;487 case Opt_dax_enum:488 if (!erofs_fc_set_dax_mode(fc, result.uint_32))489 return -EINVAL;490 break;491 case Opt_device:492 dif = kzalloc(sizeof(*dif), GFP_KERNEL);493 if (!dif)494 return -ENOMEM;495 dif->path = kstrdup(param->string, GFP_KERNEL);496 if (!dif->path) {497 kfree(dif);498 return -ENOMEM;499 }500 down_write(&sbi->devs->rwsem);501 ret = idr_alloc(&sbi->devs->tree, dif, 0, 0, GFP_KERNEL);502 up_write(&sbi->devs->rwsem);503 if (ret < 0) {504 kfree(dif->path);505 kfree(dif);506 return ret;507 }508 ++sbi->devs->extra_devices;509 break;510#ifdef CONFIG_EROFS_FS_ONDEMAND511 case Opt_fsid:512 kfree(sbi->fsid);513 sbi->fsid = kstrdup(param->string, GFP_KERNEL);514 if (!sbi->fsid)515 return -ENOMEM;516 break;517 case Opt_domain_id:518 kfree(sbi->domain_id);519 sbi->domain_id = kstrdup(param->string, GFP_KERNEL);520 if (!sbi->domain_id)521 return -ENOMEM;522 break;523#else524 case Opt_fsid:525 case Opt_domain_id:526 errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name);527 break;528#endif529 default:530 return -ENOPARAM;531 }532 return 0;533}534 535static struct inode *erofs_nfs_get_inode(struct super_block *sb,536 u64 ino, u32 generation)537{538 return erofs_iget(sb, ino);539}540 541static struct dentry *erofs_fh_to_dentry(struct super_block *sb,542 struct fid *fid, int fh_len, int fh_type)543{544 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,545 erofs_nfs_get_inode);546}547 548static struct dentry *erofs_fh_to_parent(struct super_block *sb,549 struct fid *fid, int fh_len, int fh_type)550{551 return generic_fh_to_parent(sb, fid, fh_len, fh_type,552 erofs_nfs_get_inode);553}554 555static struct dentry *erofs_get_parent(struct dentry *child)556{557 erofs_nid_t nid;558 unsigned int d_type;559 int err;560 561 err = erofs_namei(d_inode(child), &dotdot_name, &nid, &d_type);562 if (err)563 return ERR_PTR(err);564 return d_obtain_alias(erofs_iget(child->d_sb, nid));565}566 567static const struct export_operations erofs_export_ops = {568 .encode_fh = generic_encode_ino32_fh,569 .fh_to_dentry = erofs_fh_to_dentry,570 .fh_to_parent = erofs_fh_to_parent,571 .get_parent = erofs_get_parent,572};573 574static void erofs_set_sysfs_name(struct super_block *sb)575{576 struct erofs_sb_info *sbi = EROFS_SB(sb);577 578 if (sbi->domain_id)579 super_set_sysfs_name_generic(sb, "%s,%s", sbi->domain_id,580 sbi->fsid);581 else if (sbi->fsid)582 super_set_sysfs_name_generic(sb, "%s", sbi->fsid);583 else if (erofs_is_fileio_mode(sbi))584 super_set_sysfs_name_generic(sb, "%s",585 bdi_dev_name(sb->s_bdi));586 else587 super_set_sysfs_name_id(sb);588}589 590static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)591{592 struct inode *inode;593 struct erofs_sb_info *sbi = EROFS_SB(sb);594 int err;595 596 sb->s_magic = EROFS_SUPER_MAGIC;597 sb->s_flags |= SB_RDONLY | SB_NOATIME;598 sb->s_maxbytes = MAX_LFS_FILESIZE;599 sb->s_op = &erofs_sops;600 601 sbi->blkszbits = PAGE_SHIFT;602 if (!sb->s_bdev) {603 sb->s_blocksize = PAGE_SIZE;604 sb->s_blocksize_bits = PAGE_SHIFT;605 606 if (erofs_is_fscache_mode(sb)) {607 err = erofs_fscache_register_fs(sb);608 if (err)609 return err;610 }611 err = super_setup_bdi(sb);612 if (err)613 return err;614 } else {615 if (!sb_set_blocksize(sb, PAGE_SIZE)) {616 errorfc(fc, "failed to set initial blksize");617 return -EINVAL;618 }619 620 sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev,621 &sbi->dax_part_off,622 NULL, NULL);623 }624 625 err = erofs_read_superblock(sb);626 if (err)627 return err;628 629 if (sb->s_blocksize_bits != sbi->blkszbits) {630 if (erofs_is_fscache_mode(sb)) {631 errorfc(fc, "unsupported blksize for fscache mode");632 return -EINVAL;633 }634 if (!sb_set_blocksize(sb, 1 << sbi->blkszbits)) {635 errorfc(fc, "failed to set erofs blksize");636 return -EINVAL;637 }638 }639 640 if (test_opt(&sbi->opt, DAX_ALWAYS)) {641 if (!sbi->dax_dev) {642 errorfc(fc, "DAX unsupported by block device. Turning off DAX.");643 clear_opt(&sbi->opt, DAX_ALWAYS);644 } else if (sbi->blkszbits != PAGE_SHIFT) {645 errorfc(fc, "unsupported blocksize for DAX");646 clear_opt(&sbi->opt, DAX_ALWAYS);647 }648 }649 650 sb->s_time_gran = 1;651 sb->s_xattr = erofs_xattr_handlers;652 sb->s_export_op = &erofs_export_ops;653 654 if (test_opt(&sbi->opt, POSIX_ACL))655 sb->s_flags |= SB_POSIXACL;656 else657 sb->s_flags &= ~SB_POSIXACL;658 659#ifdef CONFIG_EROFS_FS_ZIP660 xa_init(&sbi->managed_pslots);661#endif662 663 inode = erofs_iget(sb, sbi->root_nid);664 if (IS_ERR(inode))665 return PTR_ERR(inode);666 667 if (!S_ISDIR(inode->i_mode)) {668 erofs_err(sb, "rootino(nid %llu) is not a directory(i_mode %o)",669 sbi->root_nid, inode->i_mode);670 iput(inode);671 return -EINVAL;672 }673 674 sb->s_root = d_make_root(inode);675 if (!sb->s_root)676 return -ENOMEM;677 678 erofs_shrinker_register(sb);679 if (erofs_sb_has_fragments(sbi) && sbi->packed_nid) {680 sbi->packed_inode = erofs_iget(sb, sbi->packed_nid);681 if (IS_ERR(sbi->packed_inode)) {682 err = PTR_ERR(sbi->packed_inode);683 sbi->packed_inode = NULL;684 return err;685 }686 }687 err = erofs_init_managed_cache(sb);688 if (err)689 return err;690 691 err = erofs_xattr_prefixes_init(sb);692 if (err)693 return err;694 695 erofs_set_sysfs_name(sb);696 err = erofs_register_sysfs(sb);697 if (err)698 return err;699 700 erofs_info(sb, "mounted with root inode @ nid %llu.", sbi->root_nid);701 return 0;702}703 704static int erofs_fc_get_tree(struct fs_context *fc)705{706 struct erofs_sb_info *sbi = fc->s_fs_info;707 int ret;708 709 if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && sbi->fsid)710 return get_tree_nodev(fc, erofs_fc_fill_super);711 712 ret = get_tree_bdev_flags(fc, erofs_fc_fill_super,713 IS_ENABLED(CONFIG_EROFS_FS_BACKED_BY_FILE) ?714 GET_TREE_BDEV_QUIET_LOOKUP : 0);715#ifdef CONFIG_EROFS_FS_BACKED_BY_FILE716 if (ret == -ENOTBLK) {717 if (!fc->source)718 return invalf(fc, "No source specified");719 sbi->fdev = filp_open(fc->source, O_RDONLY | O_LARGEFILE, 0);720 if (IS_ERR(sbi->fdev))721 return PTR_ERR(sbi->fdev);722 723 if (S_ISREG(file_inode(sbi->fdev)->i_mode) &&724 sbi->fdev->f_mapping->a_ops->read_folio)725 return get_tree_nodev(fc, erofs_fc_fill_super);726 fput(sbi->fdev);727 }728#endif729 return ret;730}731 732static int erofs_fc_reconfigure(struct fs_context *fc)733{734 struct super_block *sb = fc->root->d_sb;735 struct erofs_sb_info *sbi = EROFS_SB(sb);736 struct erofs_sb_info *new_sbi = fc->s_fs_info;737 738 DBG_BUGON(!sb_rdonly(sb));739 740 if (new_sbi->fsid || new_sbi->domain_id)741 erofs_info(sb, "ignoring reconfiguration for fsid|domain_id.");742 743 if (test_opt(&new_sbi->opt, POSIX_ACL))744 fc->sb_flags |= SB_POSIXACL;745 else746 fc->sb_flags &= ~SB_POSIXACL;747 748 sbi->opt = new_sbi->opt;749 750 fc->sb_flags |= SB_RDONLY;751 return 0;752}753 754static int erofs_release_device_info(int id, void *ptr, void *data)755{756 struct erofs_device_info *dif = ptr;757 758 fs_put_dax(dif->dax_dev, NULL);759 if (dif->file)760 fput(dif->file);761 erofs_fscache_unregister_cookie(dif->fscache);762 dif->fscache = NULL;763 kfree(dif->path);764 kfree(dif);765 return 0;766}767 768static void erofs_free_dev_context(struct erofs_dev_context *devs)769{770 if (!devs)771 return;772 idr_for_each(&devs->tree, &erofs_release_device_info, NULL);773 idr_destroy(&devs->tree);774 kfree(devs);775}776 777static void erofs_fc_free(struct fs_context *fc)778{779 struct erofs_sb_info *sbi = fc->s_fs_info;780 781 if (!sbi)782 return;783 784 erofs_free_dev_context(sbi->devs);785 kfree(sbi->fsid);786 kfree(sbi->domain_id);787 kfree(sbi);788}789 790static const struct fs_context_operations erofs_context_ops = {791 .parse_param = erofs_fc_parse_param,792 .get_tree = erofs_fc_get_tree,793 .reconfigure = erofs_fc_reconfigure,794 .free = erofs_fc_free,795};796 797static int erofs_init_fs_context(struct fs_context *fc)798{799 struct erofs_sb_info *sbi;800 801 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);802 if (!sbi)803 return -ENOMEM;804 805 sbi->devs = kzalloc(sizeof(struct erofs_dev_context), GFP_KERNEL);806 if (!sbi->devs) {807 kfree(sbi);808 return -ENOMEM;809 }810 fc->s_fs_info = sbi;811 812 idr_init(&sbi->devs->tree);813 init_rwsem(&sbi->devs->rwsem);814 erofs_default_options(sbi);815 fc->ops = &erofs_context_ops;816 return 0;817}818 819static void erofs_kill_sb(struct super_block *sb)820{821 struct erofs_sb_info *sbi = EROFS_SB(sb);822 823 if ((IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && sbi->fsid) || sbi->fdev)824 kill_anon_super(sb);825 else826 kill_block_super(sb);827 828 erofs_free_dev_context(sbi->devs);829 fs_put_dax(sbi->dax_dev, NULL);830 erofs_fscache_unregister_fs(sb);831 kfree(sbi->fsid);832 kfree(sbi->domain_id);833 if (sbi->fdev)834 fput(sbi->fdev);835 kfree(sbi);836 sb->s_fs_info = NULL;837}838 839static void erofs_put_super(struct super_block *sb)840{841 struct erofs_sb_info *const sbi = EROFS_SB(sb);842 843 DBG_BUGON(!sbi);844 845 erofs_unregister_sysfs(sb);846 erofs_shrinker_unregister(sb);847 erofs_xattr_prefixes_cleanup(sb);848#ifdef CONFIG_EROFS_FS_ZIP849 iput(sbi->managed_cache);850 sbi->managed_cache = NULL;851#endif852 iput(sbi->packed_inode);853 sbi->packed_inode = NULL;854 erofs_free_dev_context(sbi->devs);855 sbi->devs = NULL;856 erofs_fscache_unregister_fs(sb);857}858 859static struct file_system_type erofs_fs_type = {860 .owner = THIS_MODULE,861 .name = "erofs",862 .init_fs_context = erofs_init_fs_context,863 .kill_sb = erofs_kill_sb,864 .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,865};866MODULE_ALIAS_FS("erofs");867 868static int __init erofs_module_init(void)869{870 int err;871 872 erofs_check_ondisk_layout_definitions();873 874 erofs_inode_cachep = kmem_cache_create("erofs_inode",875 sizeof(struct erofs_inode), 0,876 SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,877 erofs_inode_init_once);878 if (!erofs_inode_cachep)879 return -ENOMEM;880 881 err = erofs_init_shrinker();882 if (err)883 goto shrinker_err;884 885 err = z_erofs_init_subsystem();886 if (err)887 goto zip_err;888 889 err = erofs_init_sysfs();890 if (err)891 goto sysfs_err;892 893 err = register_filesystem(&erofs_fs_type);894 if (err)895 goto fs_err;896 897 return 0;898 899fs_err:900 erofs_exit_sysfs();901sysfs_err:902 z_erofs_exit_subsystem();903zip_err:904 erofs_exit_shrinker();905shrinker_err:906 kmem_cache_destroy(erofs_inode_cachep);907 return err;908}909 910static void __exit erofs_module_exit(void)911{912 unregister_filesystem(&erofs_fs_type);913 914 /* Ensure all RCU free inodes / pclusters are safe to be destroyed. */915 rcu_barrier();916 917 erofs_exit_sysfs();918 z_erofs_exit_subsystem();919 erofs_exit_shrinker();920 kmem_cache_destroy(erofs_inode_cachep);921}922 923static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf)924{925 struct super_block *sb = dentry->d_sb;926 struct erofs_sb_info *sbi = EROFS_SB(sb);927 928 buf->f_type = sb->s_magic;929 buf->f_bsize = sb->s_blocksize;930 buf->f_blocks = sbi->total_blocks;931 buf->f_bfree = buf->f_bavail = 0;932 buf->f_files = ULLONG_MAX;933 buf->f_ffree = ULLONG_MAX - sbi->inos;934 buf->f_namelen = EROFS_NAME_LEN;935 936 if (uuid_is_null(&sb->s_uuid))937 buf->f_fsid = u64_to_fsid(!sb->s_bdev ? 0 :938 huge_encode_dev(sb->s_bdev->bd_dev));939 else940 buf->f_fsid = uuid_to_fsid(sb->s_uuid.b);941 return 0;942}943 944static int erofs_show_options(struct seq_file *seq, struct dentry *root)945{946 struct erofs_sb_info *sbi = EROFS_SB(root->d_sb);947 struct erofs_mount_opts *opt = &sbi->opt;948 949 if (IS_ENABLED(CONFIG_EROFS_FS_XATTR))950 seq_puts(seq, test_opt(opt, XATTR_USER) ?951 ",user_xattr" : ",nouser_xattr");952 if (IS_ENABLED(CONFIG_EROFS_FS_POSIX_ACL))953 seq_puts(seq, test_opt(opt, POSIX_ACL) ? ",acl" : ",noacl");954 if (IS_ENABLED(CONFIG_EROFS_FS_ZIP))955 seq_printf(seq, ",cache_strategy=%s",956 erofs_param_cache_strategy[opt->cache_strategy].name);957 if (test_opt(opt, DAX_ALWAYS))958 seq_puts(seq, ",dax=always");959 if (test_opt(opt, DAX_NEVER))960 seq_puts(seq, ",dax=never");961#ifdef CONFIG_EROFS_FS_ONDEMAND962 if (sbi->fsid)963 seq_printf(seq, ",fsid=%s", sbi->fsid);964 if (sbi->domain_id)965 seq_printf(seq, ",domain_id=%s", sbi->domain_id);966#endif967 return 0;968}969 970const struct super_operations erofs_sops = {971 .put_super = erofs_put_super,972 .alloc_inode = erofs_alloc_inode,973 .free_inode = erofs_free_inode,974 .statfs = erofs_statfs,975 .show_options = erofs_show_options,976};977 978module_init(erofs_module_init);979module_exit(erofs_module_exit);980 981MODULE_DESCRIPTION("Enhanced ROM File System");982MODULE_AUTHOR("Gao Xiang, Chao Yu, Miao Xie, CONSUMER BG, HUAWEI Inc.");983MODULE_LICENSE("GPL");984