diff options
| -rw-r--r-- | fs/kernfs/inode.c | 5 | ||||
| -rw-r--r-- | fs/kernfs/kernfs-internal.h | 2 | ||||
| -rw-r--r-- | fs/namespace.c | 2 | ||||
| -rw-r--r-- | fs/sysfs/mount.c | 104 | ||||
| -rw-r--r-- | include/linux/kernfs.h | 28 |
5 files changed, 106 insertions, 35 deletions
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c index 9d4fab49ea2..b4cae6fd717 100644 --- a/fs/kernfs/inode.c +++ b/fs/kernfs/inode.c @@ -37,9 +37,10 @@ static const struct inode_operations sysfs_inode_operations = { .setxattr = sysfs_setxattr, }; -int __init sysfs_inode_init(void) +void __init sysfs_inode_init(void) { - return bdi_init(&sysfs_backing_dev_info); + if (bdi_init(&sysfs_backing_dev_info)) + panic("failed to init sysfs_backing_dev_info"); } static struct sysfs_inode_attrs *sysfs_init_inode_attrs(struct sysfs_dirent *sd) diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index 466943d576f..0d949885389 100644 --- a/fs/kernfs/kernfs-internal.h +++ b/fs/kernfs/kernfs-internal.h @@ -144,7 +144,7 @@ int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat); int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags); -int sysfs_inode_init(void); +void sysfs_inode_init(void); /* * dir.c diff --git a/fs/namespace.c b/fs/namespace.c index ac2ce8a766e..a511ea003f8 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2790,6 +2790,8 @@ void __init mnt_init(void) for (u = 0; u < HASH_SIZE; u++) INIT_LIST_HEAD(&mountpoint_hashtable[u]); + kernfs_init(); + err = sysfs_init(); if (err) printk(KERN_WARNING "%s: sysfs_init error: %d\n", diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index f143b203a7e..5384732700b 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -86,18 +86,24 @@ static int sysfs_set_super(struct super_block *sb, void *data) return error; } -static void free_sysfs_super_info(struct sysfs_super_info *info) +/** + * kernfs_super_ns - determine the namespace tag of a kernfs super_block + * @sb: super_block of interest + * + * Return the namespace tag associated with kernfs super_block @sb. + */ +const void *kernfs_super_ns(struct super_block *sb) { - kobj_ns_drop(KOBJ_NS_TYPE_NET, (void *)info->ns); - kfree(info); + struct sysfs_super_info *info = sysfs_info(sb); + + return info->ns; } static struct dentry *sysfs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { - struct sysfs_super_info *info; - struct super_block *sb; - int error; + struct dentry *root; + void *ns; if (!(flags & MS_KERNMOUNT)) { if (!capable(CAP_SYS_ADMIN) && !fs_fully_visible(fs_type)) @@ -107,16 +113,44 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type, return ERR_PTR(-EPERM); } + ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET); + root = kernfs_mount_ns(fs_type, flags, sysfs_root, ns); + if (IS_ERR(root)) + kobj_ns_drop(KOBJ_NS_TYPE_NET, ns); + return root; +} + +/** + * kernfs_mount_ns - kernfs mount helper + * @fs_type: file_system_type of the fs being mounted + * @flags: mount flags specified for the mount + * @root: kernfs_root of the hierarchy being mounted + * @ns: optional namespace tag of the mount + * + * This is to be called from each kernfs user's file_system_type->mount() + * implementation, which should pass through the specified @fs_type and + * @flags, and specify the hierarchy and namespace tag to mount via @root + * and @ns, respectively. + * + * The return value can be passed to the vfs layer verbatim. + */ +struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags, + struct kernfs_root *root, const void *ns) +{ + struct super_block *sb; + struct sysfs_super_info *info; + int error; + info = kzalloc(sizeof(*info), GFP_KERNEL); if (!info) return ERR_PTR(-ENOMEM); - info->root = sysfs_root; - info->ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET); + info->root = root; + info->ns = ns; sb = sget(fs_type, sysfs_test_super, sysfs_set_super, flags, info); if (IS_ERR(sb) || sb->s_fs_info != info) - free_sysfs_super_info(info); + kfree(info); if (IS_ERR(sb)) return ERR_CAST(sb); if (!sb->s_root) { @@ -133,6 +167,20 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type, static void sysfs_kill_sb(struct super_block *sb) { + kernfs_kill_sb(sb); + kobj_ns_drop(KOBJ_NS_TYPE_NET, (void *)kernfs_super_ns(sb)); +} + +/** + * kernfs_kill_sb - kill_sb for kernfs + * @sb: super_block being killed + * + * This can be used directly for file_system_type->kill_sb(). If a kernfs + * user needs extra cleanup, it can implement its own kill_sb() and call + * this function at the end. + */ +void kernfs_kill_sb(struct super_block *sb) +{ struct sysfs_super_info *info = sysfs_info(sb); struct sysfs_dirent *root_sd = sb->s_root->d_fsdata; @@ -141,7 +189,7 @@ static void sysfs_kill_sb(struct super_block *sb) * so we can't find it, before freeing sysfs_super_info. */ kill_anon_super(sb); - free_sysfs_super_info(info); + kfree(info); kernfs_put(root_sd); } @@ -152,37 +200,29 @@ static struct file_system_type sysfs_fs_type = { .fs_flags = FS_USERNS_MOUNT, }; -int __init sysfs_init(void) +void __init kernfs_init(void) { - int err; - sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache", sizeof(struct sysfs_dirent), - 0, 0, NULL); - if (!sysfs_dir_cachep) - return -ENOMEM; + 0, SLAB_PANIC, NULL); + sysfs_inode_init(); +} - err = sysfs_inode_init(); - if (err) - goto out_err; +int __init sysfs_init(void) +{ + int err; sysfs_root = kernfs_create_root(NULL); - if (IS_ERR(sysfs_root)) { - err = PTR_ERR(sysfs_root); - goto out_err; - } + if (IS_ERR(sysfs_root)) + return PTR_ERR(sysfs_root); + sysfs_root_sd = sysfs_root->sd; err = register_filesystem(&sysfs_fs_type); - if (err) - goto out_destroy_root; + if (err) { + kernfs_destroy_root(sysfs_root); + return err; + } return 0; - -out_destroy_root: - kernfs_destroy_root(sysfs_root); -out_err: - kmem_cache_destroy(sysfs_dir_cachep); - sysfs_dir_cachep = NULL; - return err; } diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index fad8b986800..75fcbe5c9d6 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -18,6 +18,8 @@ struct file; struct iattr; struct seq_file; struct vm_area_struct; +struct super_block; +struct file_system_type; struct sysfs_dirent; @@ -109,6 +111,13 @@ void kernfs_enable_ns(struct sysfs_dirent *sd); int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr); void kernfs_notify(struct sysfs_dirent *sd); +const void *kernfs_super_ns(struct super_block *sb); +struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags, + struct kernfs_root *root, const void *ns); +void kernfs_kill_sb(struct super_block *sb); + +void kernfs_init(void); + #else /* CONFIG_SYSFS */ static inline struct sysfs_dirent * @@ -160,6 +169,18 @@ static inline int kernfs_setattr(struct sysfs_dirent *sd, static inline void kernfs_notify(struct sysfs_dirent *sd) { } +static inline const void *kernfs_super_ns(struct super_block *sb) +{ return NULL; } + +static inline struct dentry * +kernfs_mount_ns(struct file_system_type *fs_type, int flags, + struct kernfs_root *root, const void *ns) +{ return ERR_PTR(-ENOSYS); } + +static inline void kernfs_kill_sb(struct super_block *sb) { } + +static inline void kernfs_init(void) { } + #endif /* CONFIG_SYSFS */ static inline struct sysfs_dirent * @@ -201,4 +222,11 @@ static inline int kernfs_remove_by_name(struct sysfs_dirent *parent, return kernfs_remove_by_name_ns(parent, name, NULL); } +static inline struct dentry * +kernfs_mount(struct file_system_type *fs_type, int flags, + struct kernfs_root *root) +{ + return kernfs_mount_ns(fs_type, flags, root, NULL); +} + #endif /* __LINUX_KERNFS_H */ |