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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C), 2008-2021, OPPO Mobile Comm Corp., Ltd.4 * https://www.oppo.com/5 */6#include <linux/sysfs.h>7#include <linux/kobject.h>8 9#include "internal.h"10 11enum {12 attr_feature,13 attr_pointer_ui,14 attr_pointer_bool,15};16 17enum {18 struct_erofs_sb_info,19 struct_erofs_mount_opts,20};21 22struct erofs_attr {23 struct attribute attr;24 short attr_id;25 int struct_type, offset;26};27 28#define EROFS_ATTR(_name, _mode, _id) \29static struct erofs_attr erofs_attr_##_name = { \30 .attr = {.name = __stringify(_name), .mode = _mode }, \31 .attr_id = attr_##_id, \32}33#define EROFS_ATTR_FUNC(_name, _mode) EROFS_ATTR(_name, _mode, _name)34#define EROFS_ATTR_FEATURE(_name) EROFS_ATTR(_name, 0444, feature)35 36#define EROFS_ATTR_OFFSET(_name, _mode, _id, _struct) \37static struct erofs_attr erofs_attr_##_name = { \38 .attr = {.name = __stringify(_name), .mode = _mode }, \39 .attr_id = attr_##_id, \40 .struct_type = struct_##_struct, \41 .offset = offsetof(struct _struct, _name),\42}43 44#define EROFS_ATTR_RW(_name, _id, _struct) \45 EROFS_ATTR_OFFSET(_name, 0644, _id, _struct)46 47#define EROFS_RO_ATTR(_name, _id, _struct) \48 EROFS_ATTR_OFFSET(_name, 0444, _id, _struct)49 50#define EROFS_ATTR_RW_UI(_name, _struct) \51 EROFS_ATTR_RW(_name, pointer_ui, _struct)52 53#define EROFS_ATTR_RW_BOOL(_name, _struct) \54 EROFS_ATTR_RW(_name, pointer_bool, _struct)55 56#define ATTR_LIST(name) (&erofs_attr_##name.attr)57 58#ifdef CONFIG_EROFS_FS_ZIP59EROFS_ATTR_RW_UI(sync_decompress, erofs_mount_opts);60#endif61 62static struct attribute *erofs_attrs[] = {63#ifdef CONFIG_EROFS_FS_ZIP64 ATTR_LIST(sync_decompress),65#endif66 NULL,67};68ATTRIBUTE_GROUPS(erofs);69 70/* Features this copy of erofs supports */71EROFS_ATTR_FEATURE(zero_padding);72EROFS_ATTR_FEATURE(compr_cfgs);73EROFS_ATTR_FEATURE(big_pcluster);74EROFS_ATTR_FEATURE(chunked_file);75EROFS_ATTR_FEATURE(device_table);76EROFS_ATTR_FEATURE(compr_head2);77EROFS_ATTR_FEATURE(sb_chksum);78EROFS_ATTR_FEATURE(ztailpacking);79EROFS_ATTR_FEATURE(fragments);80EROFS_ATTR_FEATURE(dedupe);81 82static struct attribute *erofs_feat_attrs[] = {83 ATTR_LIST(zero_padding),84 ATTR_LIST(compr_cfgs),85 ATTR_LIST(big_pcluster),86 ATTR_LIST(chunked_file),87 ATTR_LIST(device_table),88 ATTR_LIST(compr_head2),89 ATTR_LIST(sb_chksum),90 ATTR_LIST(ztailpacking),91 ATTR_LIST(fragments),92 ATTR_LIST(dedupe),93 NULL,94};95ATTRIBUTE_GROUPS(erofs_feat);96 97static unsigned char *__struct_ptr(struct erofs_sb_info *sbi,98 int struct_type, int offset)99{100 if (struct_type == struct_erofs_sb_info)101 return (unsigned char *)sbi + offset;102 if (struct_type == struct_erofs_mount_opts)103 return (unsigned char *)&sbi->opt + offset;104 return NULL;105}106 107static ssize_t erofs_attr_show(struct kobject *kobj,108 struct attribute *attr, char *buf)109{110 struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,111 s_kobj);112 struct erofs_attr *a = container_of(attr, struct erofs_attr, attr);113 unsigned char *ptr = __struct_ptr(sbi, a->struct_type, a->offset);114 115 switch (a->attr_id) {116 case attr_feature:117 return sysfs_emit(buf, "supported\n");118 case attr_pointer_ui:119 if (!ptr)120 return 0;121 return sysfs_emit(buf, "%u\n", *(unsigned int *)ptr);122 case attr_pointer_bool:123 if (!ptr)124 return 0;125 return sysfs_emit(buf, "%d\n", *(bool *)ptr);126 }127 return 0;128}129 130static ssize_t erofs_attr_store(struct kobject *kobj, struct attribute *attr,131 const char *buf, size_t len)132{133 struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,134 s_kobj);135 struct erofs_attr *a = container_of(attr, struct erofs_attr, attr);136 unsigned char *ptr = __struct_ptr(sbi, a->struct_type, a->offset);137 unsigned long t;138 int ret;139 140 switch (a->attr_id) {141 case attr_pointer_ui:142 if (!ptr)143 return 0;144 ret = kstrtoul(skip_spaces(buf), 0, &t);145 if (ret)146 return ret;147 if (t != (unsigned int)t)148 return -ERANGE;149#ifdef CONFIG_EROFS_FS_ZIP150 if (!strcmp(a->attr.name, "sync_decompress") &&151 (t > EROFS_SYNC_DECOMPRESS_FORCE_OFF))152 return -EINVAL;153#endif154 *(unsigned int *)ptr = t;155 return len;156 case attr_pointer_bool:157 if (!ptr)158 return 0;159 ret = kstrtoul(skip_spaces(buf), 0, &t);160 if (ret)161 return ret;162 if (t != 0 && t != 1)163 return -EINVAL;164 *(bool *)ptr = !!t;165 return len;166 }167 return 0;168}169 170static void erofs_sb_release(struct kobject *kobj)171{172 struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,173 s_kobj);174 complete(&sbi->s_kobj_unregister);175}176 177static const struct sysfs_ops erofs_attr_ops = {178 .show = erofs_attr_show,179 .store = erofs_attr_store,180};181 182static const struct kobj_type erofs_sb_ktype = {183 .default_groups = erofs_groups,184 .sysfs_ops = &erofs_attr_ops,185 .release = erofs_sb_release,186};187 188static const struct kobj_type erofs_ktype = {189 .sysfs_ops = &erofs_attr_ops,190};191 192static struct kset erofs_root = {193 .kobj = {.ktype = &erofs_ktype},194};195 196static const struct kobj_type erofs_feat_ktype = {197 .default_groups = erofs_feat_groups,198 .sysfs_ops = &erofs_attr_ops,199};200 201static struct kobject erofs_feat = {202 .kset = &erofs_root,203};204 205int erofs_register_sysfs(struct super_block *sb)206{207 struct erofs_sb_info *sbi = EROFS_SB(sb);208 int err;209 210 sbi->s_kobj.kset = &erofs_root;211 init_completion(&sbi->s_kobj_unregister);212 err = kobject_init_and_add(&sbi->s_kobj, &erofs_sb_ktype, NULL, "%s",213 sb->s_sysfs_name);214 if (err) {215 kobject_put(&sbi->s_kobj);216 wait_for_completion(&sbi->s_kobj_unregister);217 }218 return err;219}220 221void erofs_unregister_sysfs(struct super_block *sb)222{223 struct erofs_sb_info *sbi = EROFS_SB(sb);224 225 if (sbi->s_kobj.state_in_sysfs) {226 kobject_del(&sbi->s_kobj);227 kobject_put(&sbi->s_kobj);228 wait_for_completion(&sbi->s_kobj_unregister);229 }230}231 232int __init erofs_init_sysfs(void)233{234 int ret;235 236 kobject_set_name(&erofs_root.kobj, "erofs");237 erofs_root.kobj.parent = fs_kobj;238 ret = kset_register(&erofs_root);239 if (ret)240 goto root_err;241 242 ret = kobject_init_and_add(&erofs_feat, &erofs_feat_ktype,243 NULL, "features");244 if (ret)245 goto feat_err;246 return ret;247 248feat_err:249 kobject_put(&erofs_feat);250 kset_unregister(&erofs_root);251root_err:252 return ret;253}254 255void erofs_exit_sysfs(void)256{257 kobject_put(&erofs_feat);258 kset_unregister(&erofs_root);259}260