diff --git a/Documentation/filesystems/tmpfs.rst b/Documentation/filesystems/tmpfs.rst index 56a26c843dbe..d677e0428c3f 100644 --- a/Documentation/filesystems/tmpfs.rst +++ b/Documentation/filesystems/tmpfs.rst @@ -241,6 +241,28 @@ So 'mount -t tmpfs -o size=10G,nr_inodes=10k,mode=700 tmpfs /mytmpfs' will give you tmpfs instance on /mytmpfs which can allocate 10GB RAM/SWAP in 10240 inodes and it is only accessible by root. +tmpfs has the following mounting options for case-insensitive lookup support: + +================= ============================================================== +casefold Enable casefold support at this mount point using the given + argument as the encoding standard. Currently only UTF-8 + encodings are supported. If no argument is used, it will load + the latest UTF-8 encoding available. +strict_encoding Enable strict encoding at this mount point (disabled by + default). In this mode, the filesystem refuses to create file + and directory with names containing invalid UTF-8 characters. +================= ============================================================== + +This option doesn't render the entire filesystem case-insensitive. One needs to +still set the casefold flag per directory, by flipping the +F attribute in an +empty directory. Nevertheless, new directories will inherit the attribute. The +mountpoint itself cannot be made case-insensitive. + +Example:: + + $ mount -t tmpfs -o casefold=utf8-12.1.0,strict_encoding fs_name /mytmpfs + $ mount -t tmpfs -o casefold fs_name /mytmpfs + :Author: Christoph Rohland , 1.12.01 @@ -250,3 +272,5 @@ RAM/SWAP in 10240 inodes and it is only accessible by root. KOSAKI Motohiro, 16 Mar 2010 :Updated: Chris Down, 13 July 2020 +:Updated: + André Almeida, 23 Aug 2024 diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 790db7eac6c2..612ccbeb493b 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2395,11 +2395,8 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry, if (fscrypt_is_nokey_name(dentry)) return -ENOKEY; -#if IS_ENABLED(CONFIG_UNICODE) - if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) && - utf8_validate(sb->s_encoding, &dentry->d_name)) + if (!generic_ci_validate_strict_name(dir, &dentry->d_name)) return -EINVAL; -#endif retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname); if (retval) diff --git a/fs/libfs.c b/fs/libfs.c index 46966fd8bcf9..a168ece5cc61 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -77,6 +77,10 @@ struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, unsigned return ERR_PTR(-ENAMETOOLONG); if (!dentry->d_sb->s_d_op) d_set_d_op(dentry, &simple_dentry_operations); + + if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir)) + return NULL; + d_add(dentry, NULL); return NULL; } @@ -1791,8 +1795,8 @@ bool is_empty_dir_inode(struct inode *inode) * * Return: 0 if names match, 1 if mismatch, or -ERRNO */ -static int generic_ci_d_compare(const struct dentry *dentry, unsigned int len, - const char *str, const struct qstr *name) +int generic_ci_d_compare(const struct dentry *dentry, unsigned int len, + const char *str, const struct qstr *name) { const struct dentry *parent; const struct inode *dir; @@ -1835,6 +1839,7 @@ static int generic_ci_d_compare(const struct dentry *dentry, unsigned int len, return utf8_strncasecmp(dentry->d_sb->s_encoding, name, &qstr); } +EXPORT_SYMBOL(generic_ci_d_compare); /** * generic_ci_d_hash - generic d_hash implementation for casefolding filesystems @@ -1843,7 +1848,7 @@ static int generic_ci_d_compare(const struct dentry *dentry, unsigned int len, * * Return: 0 if hash was successful or unchanged, and -EINVAL on error */ -static int generic_ci_d_hash(const struct dentry *dentry, struct qstr *str) +int generic_ci_d_hash(const struct dentry *dentry, struct qstr *str) { const struct inode *dir = READ_ONCE(dentry->d_inode); struct super_block *sb = dentry->d_sb; @@ -1858,6 +1863,7 @@ static int generic_ci_d_hash(const struct dentry *dentry, struct qstr *str) return -EINVAL; return 0; } +EXPORT_SYMBOL(generic_ci_d_hash); static const struct dentry_operations generic_ci_dentry_ops = { .d_hash = generic_ci_d_hash, diff --git a/fs/unicode/utf8-core.c b/fs/unicode/utf8-core.c index 8395066341a4..7f7cb14e01ce 100644 --- a/fs/unicode/utf8-core.c +++ b/fs/unicode/utf8-core.c @@ -214,3 +214,29 @@ void utf8_unload(struct unicode_map *um) } EXPORT_SYMBOL(utf8_unload); +/** + * utf8_parse_version - Parse a UTF-8 version number from a string + * + * @version: input string + * + * Returns the parsed version on success, negative code on error + */ +int utf8_parse_version(char *version) +{ + substring_t args[3]; + unsigned int maj, min, rev; + static const struct match_token token[] = { + {1, "%d.%d.%d"}, + {0, NULL} + }; + + if (match_token(version, token, args) != 1) + return -EINVAL; + + if (match_int(&args[0], &maj) || match_int(&args[1], &min) || + match_int(&args[2], &rev)) + return -EINVAL; + + return UNICODE_AGE(maj, min, rev); +} +EXPORT_SYMBOL(utf8_parse_version); diff --git a/fs/unicode/utf8-selftest.c b/fs/unicode/utf8-selftest.c index 600e15efe9ed..5ddaf27b21a6 100644 --- a/fs/unicode/utf8-selftest.c +++ b/fs/unicode/utf8-selftest.c @@ -17,9 +17,6 @@ static unsigned int failed_tests; static unsigned int total_tests; -/* Tests will be based on this version. */ -#define UTF8_LATEST UNICODE_AGE(12, 1, 0) - #define _test(cond, func, line, fmt, ...) do { \ total_tests++; \ if (!cond) { \ diff --git a/include/linux/fs.h b/include/linux/fs.h index 3e53ba079f17..eae7ce884030 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -46,6 +46,7 @@ #include #include #include +#include #include #include @@ -3479,6 +3480,54 @@ extern int generic_ci_match(const struct inode *parent, const struct qstr *folded_name, const u8 *de_name, u32 de_name_len); +#if IS_ENABLED(CONFIG_UNICODE) +int generic_ci_d_hash(const struct dentry *dentry, struct qstr *str); +int generic_ci_d_compare(const struct dentry *dentry, unsigned int len, + const char *str, const struct qstr *name); + +/** + * generic_ci_validate_strict_name - Check if a given name is suitable + * for a directory + * + * This functions checks if the proposed filename is valid for the + * parent directory. That means that only valid UTF-8 filenames will be + * accepted for casefold directories from filesystems created with the + * strict encoding flag. That also means that any name will be + * accepted for directories that doesn't have casefold enabled, or + * aren't being strict with the encoding. + * + * @dir: inode of the directory where the new file will be created + * @name: name of the new file + * + * Return: + * * True: if the filename is suitable for this directory. It can be + * true if a given name is not suitable for a strict encoding + * directory, but the directory being used isn't strict + * * False if the filename isn't suitable for this directory. This only + * happens when a directory is casefolded and the filesystem is strict + * about its encoding. + */ +static inline bool generic_ci_validate_strict_name(struct inode *dir, struct qstr *name) +{ + if (!IS_CASEFOLDED(dir) || !sb_has_strict_encoding(dir->i_sb)) + return true; + + /* + * A casefold dir must have a encoding set, unless the filesystem + * is corrupted + */ + if (WARN_ON_ONCE(!dir->i_sb->s_encoding)) + return true; + + return !utf8_validate(dir->i_sb->s_encoding, name); +} +#else +static inline bool generic_ci_validate_strict_name(struct inode *dir, struct qstr *name) +{ + return true; +} +#endif + static inline bool sb_has_encoding(const struct super_block *sb) { #if IS_ENABLED(CONFIG_UNICODE) diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h index 515a9a6a3c6f..018da28c01e7 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -42,10 +42,10 @@ struct shmem_inode_info { struct inode vfs_inode; }; -#define SHMEM_FL_USER_VISIBLE FS_FL_USER_VISIBLE +#define SHMEM_FL_USER_VISIBLE (FS_FL_USER_VISIBLE | FS_CASEFOLD_FL) #define SHMEM_FL_USER_MODIFIABLE \ - (FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | FS_NOATIME_FL) -#define SHMEM_FL_INHERITED (FS_NODUMP_FL | FS_NOATIME_FL) + (FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | FS_NOATIME_FL | FS_CASEFOLD_FL) +#define SHMEM_FL_INHERITED (FS_NODUMP_FL | FS_NOATIME_FL | FS_CASEFOLD_FL) struct shmem_quota_limits { qsize_t usrquota_bhardlimit; /* Default user quota block hard limit */ diff --git a/include/linux/unicode.h b/include/linux/unicode.h index 4d39e6e11a95..5e6b212a2aed 100644 --- a/include/linux/unicode.h +++ b/include/linux/unicode.h @@ -16,6 +16,8 @@ struct utf8data_table; ((unsigned int)(MIN) << UNICODE_MIN_SHIFT) | \ ((unsigned int)(REV))) +#define UTF8_LATEST UNICODE_AGE(12, 1, 0) + static inline u8 unicode_major(unsigned int age) { return (age >> UNICODE_MAJ_SHIFT) & 0xff; @@ -76,4 +78,6 @@ int utf8_casefold_hash(const struct unicode_map *um, const void *salt, struct unicode_map *utf8_load(unsigned int version); void utf8_unload(struct unicode_map *um); +int utf8_parse_version(char *version); + #endif /* _LINUX_UNICODE_H */ diff --git a/mm/shmem.c b/mm/shmem.c index 87c9e38c0763..c7881e16f4be 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -40,6 +40,7 @@ #include #include #include +#include #include "swap.h" static struct vfsmount *shm_mnt __ro_after_init; @@ -123,6 +124,10 @@ struct shmem_options { bool noswap; unsigned short quota_types; struct shmem_quota_limits qlimits; +#if IS_ENABLED(CONFIG_UNICODE) + struct unicode_map *encoding; + bool strict_encoding; +#endif #define SHMEM_SEEN_BLOCKS 1 #define SHMEM_SEEN_INODES 2 #define SHMEM_SEEN_HUGE 4 @@ -2749,13 +2754,62 @@ static int shmem_file_open(struct inode *inode, struct file *file) #ifdef CONFIG_TMPFS_XATTR static int shmem_initxattrs(struct inode *, const struct xattr *, void *); +#if IS_ENABLED(CONFIG_UNICODE) +/* + * shmem_inode_casefold_flags - Deal with casefold file attribute flag + * + * The casefold file attribute needs some special checks. I can just be added to + * an empty dir, and can't be removed from a non-empty dir. + */ +static int shmem_inode_casefold_flags(struct inode *inode, unsigned int fsflags, + struct dentry *dentry, unsigned int *i_flags) +{ + unsigned int old = inode->i_flags; + struct super_block *sb = inode->i_sb; + + if (fsflags & FS_CASEFOLD_FL) { + if (!(old & S_CASEFOLD)) { + if (!sb->s_encoding) + return -EOPNOTSUPP; + + if (!S_ISDIR(inode->i_mode)) + return -ENOTDIR; + + if (dentry && !simple_empty(dentry)) + return -ENOTEMPTY; + } + + *i_flags = *i_flags | S_CASEFOLD; + } else if (old & S_CASEFOLD) { + if (dentry && !simple_empty(dentry)) + return -ENOTEMPTY; + } + + return 0; +} +#else +static int shmem_inode_casefold_flags(struct inode *inode, unsigned int fsflags, + struct dentry *dentry, unsigned int *i_flags) +{ + if (fsflags & FS_CASEFOLD_FL) + return -EOPNOTSUPP; + + return 0; +} +#endif + /* * chattr's fsflags are unrelated to extended attributes, * but tmpfs has chosen to enable them under the same config option. */ -static void shmem_set_inode_flags(struct inode *inode, unsigned int fsflags) +static int shmem_set_inode_flags(struct inode *inode, unsigned int fsflags, struct dentry *dentry) { unsigned int i_flags = 0; + int ret; + + ret = shmem_inode_casefold_flags(inode, fsflags, dentry, &i_flags); + if (ret) + return ret; if (fsflags & FS_NOATIME_FL) i_flags |= S_NOATIME; @@ -2766,10 +2820,12 @@ static void shmem_set_inode_flags(struct inode *inode, unsigned int fsflags) /* * But FS_NODUMP_FL does not require any action in i_flags. */ - inode_set_flags(inode, i_flags, S_NOATIME | S_APPEND | S_IMMUTABLE); + inode_set_flags(inode, i_flags, S_NOATIME | S_APPEND | S_IMMUTABLE | S_CASEFOLD); + + return 0; } #else -static void shmem_set_inode_flags(struct inode *inode, unsigned int fsflags) +static void shmem_set_inode_flags(struct inode *inode, unsigned int fsflags, struct dentry *dentry) { } #define shmem_initxattrs NULL @@ -2816,7 +2872,7 @@ static struct inode *__shmem_get_inode(struct mnt_idmap *idmap, info->fsflags = (dir == NULL) ? 0 : SHMEM_I(dir)->fsflags & SHMEM_FL_INHERITED; if (info->fsflags) - shmem_set_inode_flags(inode, info->fsflags); + shmem_set_inode_flags(inode, info->fsflags, NULL); INIT_LIST_HEAD(&info->shrinklist); INIT_LIST_HEAD(&info->swaplist); simple_xattrs_init(&info->xattrs); @@ -3562,6 +3618,9 @@ shmem_mknod(struct mnt_idmap *idmap, struct inode *dir, struct inode *inode; int error; + if (!generic_ci_validate_strict_name(dir, &dentry->d_name)) + return -EINVAL; + inode = shmem_get_inode(idmap, dir->i_sb, dir, mode, dev, VM_NORESERVE); if (IS_ERR(inode)) return PTR_ERR(inode); @@ -3581,7 +3640,12 @@ shmem_mknod(struct mnt_idmap *idmap, struct inode *dir, dir->i_size += BOGO_DIRENT_SIZE; inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); inode_inc_iversion(dir); - d_instantiate(dentry, inode); + + if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir)) + d_add(dentry, inode); + else + d_instantiate(dentry, inode); + dget(dentry); /* Extra count - pin the dentry in core */ return error; @@ -3672,7 +3736,10 @@ static int shmem_link(struct dentry *old_dentry, struct inode *dir, inc_nlink(inode); ihold(inode); /* New dentry reference */ dget(dentry); /* Extra pinning count for the created dentry */ - d_instantiate(dentry, inode); + if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir)) + d_add(dentry, inode); + else + d_instantiate(dentry, inode); out: return ret; } @@ -3692,6 +3759,14 @@ static int shmem_unlink(struct inode *dir, struct dentry *dentry) inode_inc_iversion(dir); drop_nlink(inode); dput(dentry); /* Undo the count from "create" - does all the work */ + + /* + * For now, VFS can't deal with case-insensitive negative dentries, so + * we invalidate them + */ + if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir)) + d_invalidate(dentry); + return 0; } @@ -3836,7 +3911,10 @@ static int shmem_symlink(struct mnt_idmap *idmap, struct inode *dir, dir->i_size += BOGO_DIRENT_SIZE; inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); inode_inc_iversion(dir); - d_instantiate(dentry, inode); + if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir)) + d_add(dentry, inode); + else + d_instantiate(dentry, inode); dget(dentry); return 0; @@ -3901,16 +3979,23 @@ static int shmem_fileattr_set(struct mnt_idmap *idmap, { struct inode *inode = d_inode(dentry); struct shmem_inode_info *info = SHMEM_I(inode); + int ret, flags; if (fileattr_has_fsx(fa)) return -EOPNOTSUPP; if (fa->flags & ~SHMEM_FL_USER_MODIFIABLE) return -EOPNOTSUPP; - info->fsflags = (info->fsflags & ~SHMEM_FL_USER_MODIFIABLE) | + flags = (info->fsflags & ~SHMEM_FL_USER_MODIFIABLE) | (fa->flags & SHMEM_FL_USER_MODIFIABLE); - shmem_set_inode_flags(inode, info->fsflags); + ret = shmem_set_inode_flags(inode, flags, dentry); + + if (ret) + return ret; + + info->fsflags = flags; + inode_set_ctime_current(inode); inode_inc_iversion(inode); return 0; @@ -4189,6 +4274,9 @@ enum shmem_param { Opt_usrquota_inode_hardlimit, Opt_grpquota_block_hardlimit, Opt_grpquota_inode_hardlimit, + Opt_casefold_version, + Opt_casefold, + Opt_strict_encoding, }; static const struct constant_table shmem_param_enums_huge[] = { @@ -4220,9 +4308,54 @@ const struct fs_parameter_spec shmem_fs_parameters[] = { fsparam_string("grpquota_block_hardlimit", Opt_grpquota_block_hardlimit), fsparam_string("grpquota_inode_hardlimit", Opt_grpquota_inode_hardlimit), #endif + fsparam_string("casefold", Opt_casefold_version), + fsparam_flag ("casefold", Opt_casefold), + fsparam_flag ("strict_encoding", Opt_strict_encoding), {} }; +#if IS_ENABLED(CONFIG_UNICODE) +static int shmem_parse_opt_casefold(struct fs_context *fc, struct fs_parameter *param, + bool latest_version) +{ + struct shmem_options *ctx = fc->fs_private; + unsigned int version = UTF8_LATEST; + struct unicode_map *encoding; + char *version_str = param->string + 5; + + if (!latest_version) { + if (strncmp(param->string, "utf8-", 5)) + return invalfc(fc, "Only UTF-8 encodings are supported " + "in the format: utf8-"); + + version = utf8_parse_version(version_str); + if (version < 0) + return invalfc(fc, "Invalid UTF-8 version: %s", version_str); + } + + encoding = utf8_load(version); + + if (IS_ERR(encoding)) { + return invalfc(fc, "Failed loading UTF-8 version: utf8-%u.%u.%u\n", + unicode_major(version), unicode_minor(version), + unicode_rev(version)); + } + + pr_info("tmpfs: Using encoding : utf8-%u.%u.%u\n", + unicode_major(version), unicode_minor(version), unicode_rev(version)); + + ctx->encoding = encoding; + + return 0; +} +#else +static int shmem_parse_opt_casefold(struct fs_context *fc, struct fs_parameter *param, + bool latest_version) +{ + return invalfc(fc, "tmpfs: Kernel not built with CONFIG_UNICODE\n"); +} +#endif + static int shmem_parse_one(struct fs_context *fc, struct fs_parameter *param) { struct shmem_options *ctx = fc->fs_private; @@ -4381,6 +4514,17 @@ static int shmem_parse_one(struct fs_context *fc, struct fs_parameter *param) "Group quota inode hardlimit too large."); ctx->qlimits.grpquota_ihardlimit = size; break; + case Opt_casefold_version: + return shmem_parse_opt_casefold(fc, param, false); + case Opt_casefold: + return shmem_parse_opt_casefold(fc, param, true); + case Opt_strict_encoding: +#if IS_ENABLED(CONFIG_UNICODE) + ctx->strict_encoding = true; + break; +#else + return invalfc(fc, "tmpfs: Kernel not built with CONFIG_UNICODE\n"); +#endif } return 0; @@ -4610,6 +4754,11 @@ static void shmem_put_super(struct super_block *sb) { struct shmem_sb_info *sbinfo = SHMEM_SB(sb); +#if IS_ENABLED(CONFIG_UNICODE) + if (sb->s_encoding) + utf8_unload(sb->s_encoding); +#endif + #ifdef CONFIG_TMPFS_QUOTA shmem_disable_quotas(sb); #endif @@ -4620,6 +4769,14 @@ static void shmem_put_super(struct super_block *sb) sb->s_fs_info = NULL; } +#if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_TMPFS) +static const struct dentry_operations shmem_ci_dentry_ops = { + .d_hash = generic_ci_d_hash, + .d_compare = generic_ci_d_compare, + .d_delete = always_delete_dentry, +}; +#endif + static int shmem_fill_super(struct super_block *sb, struct fs_context *fc) { struct shmem_options *ctx = fc->fs_private; @@ -4654,9 +4811,25 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc) } sb->s_export_op = &shmem_export_ops; sb->s_flags |= SB_NOSEC | SB_I_VERSION; + +#if IS_ENABLED(CONFIG_UNICODE) + if (!ctx->encoding && ctx->strict_encoding) { + pr_err("tmpfs: strict_encoding option without encoding is forbidden\n"); + error = -EINVAL; + goto failed; + } + + if (ctx->encoding) { + sb->s_encoding = ctx->encoding; + sb->s_d_op = &shmem_ci_dentry_ops; + if (ctx->strict_encoding) + sb->s_encoding_flags = SB_ENC_STRICT_MODE_FL; + } +#endif + #else sb->s_flags |= SB_NOUSER; -#endif +#endif /* CONFIG_TMPFS */ sbinfo->max_blocks = ctx->blocks; sbinfo->max_inodes = ctx->inodes; sbinfo->free_ispace = sbinfo->max_inodes * BOGO_INODE_SIZE; @@ -4930,6 +5103,10 @@ int shmem_init_fs_context(struct fs_context *fc) ctx->uid = current_fsuid(); ctx->gid = current_fsgid(); +#if IS_ENABLED(CONFIG_UNICODE) + ctx->encoding = NULL; +#endif + fc->fs_private = ctx; fc->ops = &shmem_fs_context_ops; return 0; @@ -4946,6 +5123,66 @@ static struct file_system_type shmem_fs_type = { .fs_flags = FS_USERNS_MOUNT | FS_ALLOW_IDMAP | FS_MGTIME, }; +#if defined(CONFIG_SYSFS) && defined(CONFIG_TMPFS) + +#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store) \ +{ \ + .attr = { .name = __stringify(_name), .mode = _mode }, \ + .show = _show, \ + .store = _store, \ +} + +#define TMPFS_ATTR_W(_name, _store) \ + static struct kobj_attribute tmpfs_attr_##_name = \ + __INIT_KOBJ_ATTR(_name, 0200, NULL, _store) + +#define TMPFS_ATTR_RW(_name, _show, _store) \ + static struct kobj_attribute tmpfs_attr_##_name = \ + __INIT_KOBJ_ATTR(_name, 0644, _show, _store) + +#define TMPFS_ATTR_RO(_name, _show) \ + static struct kobj_attribute tmpfs_attr_##_name = \ + __INIT_KOBJ_ATTR(_name, 0444, _show, NULL) + +#if IS_ENABLED(CONFIG_UNICODE) +static ssize_t casefold_show(struct kobject *kobj, struct kobj_attribute *a, + char *buf) +{ + return sysfs_emit(buf, "supported\n"); +} +TMPFS_ATTR_RO(casefold, casefold_show); +#endif + +static struct attribute *tmpfs_attributes[] = { +#if IS_ENABLED(CONFIG_UNICODE) + &tmpfs_attr_casefold.attr, +#endif + NULL +}; + +static const struct attribute_group tmpfs_attribute_group = { + .attrs = tmpfs_attributes, + .name = "features" +}; + +static struct kobject *tmpfs_kobj; + +static int __init tmpfs_sysfs_init(void) +{ + int ret; + + tmpfs_kobj = kobject_create_and_add("tmpfs", fs_kobj); + if (!tmpfs_kobj) + return -ENOMEM; + + ret = sysfs_create_group(tmpfs_kobj, &tmpfs_attribute_group); + if (ret) + kobject_put(tmpfs_kobj); + + return ret; +} +#endif /* CONFIG_SYSFS && CONFIG_TMPFS */ + void __init shmem_init(void) { int error; @@ -4969,6 +5206,14 @@ void __init shmem_init(void) goto out1; } +#if defined(CONFIG_SYSFS) && defined(CONFIG_TMPFS) + error = tmpfs_sysfs_init(); + if (error) { + pr_err("Could not init tmpfs sysfs\n"); + goto out1; + } +#endif + #ifdef CONFIG_TRANSPARENT_HUGEPAGE if (has_transparent_hugepage() && shmem_huge > SHMEM_HUGE_DENY) SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge;