From 58e55efd6c72cbc3e76423a1086f7b4d6c2ae9c2 Mon Sep 17 00:00:00 2001 From: André Almeida Date: Mon, 21 Oct 2024 13:37:22 -0300 Subject: tmpfs: Add casefold lookup support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Enable casefold lookup in tmpfs, based on the encoding defined by userspace. That means that instead of comparing byte per byte a file name, it compares to a case-insensitive equivalent of the Unicode string. * Dcache handling There's a special need when dealing with case-insensitive dentries. First of all, we currently invalidated every negative casefold dentries. That happens because currently VFS code has no proper support to deal with that, giving that it could incorrectly reuse a previous filename for a new file that has a casefold match. For instance, this could happen: $ mkdir DIR $ rm -r DIR $ mkdir dir $ ls DIR/ And would be perceived as inconsistency from userspace point of view, because even that we match files in a case-insensitive manner, we still honor whatever is the initial filename. Along with that, tmpfs stores only the first equivalent name dentry used in the dcache, preventing duplications of dentries in the dcache. The d_compare() version for casefold files uses a normalized string, so the filename under lookup will be compared to another normalized string for the existing file, achieving a casefolded lookup. * Enabling casefold via mount options Most filesystems have their data stored in disk, so casefold option need to be enabled when building a filesystem on a device (via mkfs). However, as tmpfs is a RAM backed filesystem, there's no disk information and thus no mkfs to store information about casefold. For tmpfs, create casefold options for mounting. Userspace can then enable casefold support for a mount point using: $ mount -t tmpfs -o casefold=utf8-12.1.0 fs_name mount_dir/ Userspace must set what Unicode standard is aiming to. The available options depends on what the kernel Unicode subsystem supports. And for strict encoding: $ mount -t tmpfs -o casefold=utf8-12.1.0,strict_encoding fs_name mount_dir/ Strict encoding means that tmpfs will refuse to create invalid UTF-8 sequences. When this option is not enabled, any invalid sequence will be treated as an opaque byte sequence, ignoring the encoding thus not being able to be looked up in a case-insensitive way. * Check for casefold dirs on simple_lookup() On simple_lookup(), do not create dentries for casefold directories. Currently, VFS does not support case-insensitive negative dentries and can create inconsistencies in the filesystem. Prevent such dentries to being created in the first place. Reviewed-by: Gabriel Krisman Bertazi Reviewed-by: Gabriel Krisman Bertazi Signed-off-by: André Almeida Link: https://lore.kernel.org/r/20241021-tonyk-tmpfs-v8-6-f443d5814194@igalia.com Signed-off-by: Christian Brauner --- mm/shmem.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 123 insertions(+), 4 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index c5adb987b23c..f26488ff3d6a 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 @@ -3565,6 +3570,9 @@ 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); @@ -3584,7 +3592,12 @@ 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; @@ -3675,7 +3688,10 @@ 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; } @@ -3695,6 +3711,14 @@ 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; } @@ -3839,7 +3863,10 @@ 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; @@ -4192,6 +4219,9 @@ 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[] = { @@ -4223,9 +4253,54 @@ 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; @@ -4384,6 +4459,17 @@ 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; @@ -4613,6 +4699,11 @@ 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 @@ -4623,6 +4714,14 @@ 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; @@ -4657,9 +4756,25 @@ 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; @@ -4933,6 +5048,10 @@ 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; -- cgit v1.2.3 From 5cd9aecbc72c07e8b83e900078669a7d0bc5f98f Mon Sep 17 00:00:00 2001 From: André Almeida Date: Mon, 21 Oct 2024 13:37:23 -0300 Subject: tmpfs: Add flag FS_CASEFOLD_FL support for tmpfs dirs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Enable setting flag FS_CASEFOLD_FL for tmpfs directories, when tmpfs is mounted with casefold support. A special check is need for this flag, since it can't be set for non-empty directories. Reviewed-by: Gabriel Krisman Bertazi Reviewed-by: Gabriel Krisman Bertazi Signed-off-by: André Almeida Link: https://lore.kernel.org/r/20241021-tonyk-tmpfs-v8-7-f443d5814194@igalia.com Signed-off-by: Christian Brauner --- include/linux/shmem_fs.h | 6 ++--- mm/shmem.c | 70 +++++++++++++++++++++++++++++++++++++++++++----- 2 files changed, 67 insertions(+), 9 deletions(-) (limited to 'mm/shmem.c') 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/mm/shmem.c b/mm/shmem.c index f26488ff3d6a..ea01628e4434 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2757,13 +2757,62 @@ 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; @@ -2774,10 +2823,12 @@ 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 @@ -2824,7 +2875,7 @@ 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); @@ -3931,16 +3982,23 @@ 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; -- cgit v1.2.3 From 5132f08bd3325602f4de01ccd59537c7f91e1f89 Mon Sep 17 00:00:00 2001 From: André Almeida Date: Mon, 21 Oct 2024 13:37:24 -0300 Subject: tmpfs: Expose filesystem features via sysfs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Expose filesystem features through sysfs, so userspace can query if tmpfs support casefold. This follows the same setup as defined by ext4 and f2fs to expose casefold support to userspace. Signed-off-by: André Almeida Link: https://lore.kernel.org/r/20241021-tonyk-tmpfs-v8-8-f443d5814194@igalia.com Reviewed-by: Gabriel Krisman Bertazi Signed-off-by: Christian Brauner --- mm/shmem.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index ea01628e4434..0739143d1419 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -5546,3 +5546,40 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, return page; } EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp); + +#if defined(CONFIG_SYSFS) && defined(CONFIG_TMPFS) +#if IS_ENABLED(CONFIG_UNICODE) +static DEVICE_STRING_ATTR_RO(casefold, 0444, "supported"); +#endif + +static struct attribute *tmpfs_attributes[] = { +#if IS_ENABLED(CONFIG_UNICODE) + &dev_attr_casefold.attr.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; +} + +fs_initcall(tmpfs_sysfs_init); +#endif /* CONFIG_SYSFS && CONFIG_TMPFS */ -- cgit v1.2.3 From 18d2f10f6284f5bb9c03a759044121c71e5b3b4c Mon Sep 17 00:00:00 2001 From: André Almeida Date: Fri, 1 Nov 2024 13:42:50 -0300 Subject: tmpfs: Fix type for sysfs' casefold attribute MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit DEVICE_STRING_ATTR_RO should be only used by device drivers since it relies on `struct device` to use device_show_string() function. Using this with non device code led to a kCFI violation: > cat /sys/fs/tmpfs/features/casefold [ 70.558496] CFI failure at kobj_attr_show+0x2c/0x4c (target: device_show_string+0x0/0x38; expected type: 0xc527b809) Like the other filesystems, fix this by manually declaring the attribute using kobj_attribute() and writing a proper show() function. Also, leave macros for anyone that need to expand tmpfs sysfs' with more attributes. Fixes: 5132f08bd332 ("tmpfs: Expose filesystem features via sysfs") Reported-by: Nathan Chancellor Closes: https://lore.kernel.org/lkml/20241031051822.GA2947788@thelio-3990X/ Signed-off-by: André Almeida Link: https://lore.kernel.org/r/20241101164251.327884-3-andrealmeid@igalia.com Tested-by: Nathan Chancellor Reviewed-by: Nathan Chancellor Signed-off-by: Christian Brauner --- mm/shmem.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index 0739143d1419..00ff7ef16dc6 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -5548,13 +5548,38 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp); #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 DEVICE_STRING_ATTR_RO(casefold, 0444, "supported"); +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) - &dev_attr_casefold.attr.attr, + &tmpfs_attr_casefold.attr, #endif NULL }; -- cgit v1.2.3 From 65c481f30896750f659345b915b669f78a3c0289 Mon Sep 17 00:00:00 2001 From: André Almeida Date: Fri, 1 Nov 2024 13:42:51 -0300 Subject: tmpfs: Initialize sysfs during tmpfs init MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Instead of using fs_initcall(), initialize sysfs with the rest of the filesystem. This is the right way to do it because otherwise any error during tmpfs_sysfs_init() would get silently ignored. It's also useful if tmpfs' sysfs ever need to display runtime information. Signed-off-by: André Almeida Link: https://lore.kernel.org/r/20241101164251.327884-4-andrealmeid@igalia.com Signed-off-by: Christian Brauner --- mm/shmem.c | 130 ++++++++++++++++++++++++++++++++----------------------------- 1 file changed, 68 insertions(+), 62 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index 00ff7ef16dc6..1389a29a18bf 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -5126,6 +5126,66 @@ static struct file_system_type shmem_fs_type = { .fs_flags = FS_USERNS_MOUNT | FS_ALLOW_IDMAP, }; +#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; @@ -5149,6 +5209,14 @@ 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; @@ -5546,65 +5614,3 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, return page; } EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp); - -#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; -} - -fs_initcall(tmpfs_sysfs_init); -#endif /* CONFIG_SYSFS && CONFIG_TMPFS */ -- cgit v1.2.3