diff options
Diffstat (limited to 'fs/sysfs/mount.c')
-rw-r--r-- | fs/sysfs/mount.c | 184 |
1 files changed, 25 insertions, 159 deletions
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index 834ec2cdb7a..6211230814f 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -14,146 +14,41 @@ #include <linux/fs.h> #include <linux/mount.h> -#include <linux/pagemap.h> #include <linux/init.h> -#include <linux/module.h> -#include <linux/magic.h> -#include <linux/slab.h> #include <linux/user_namespace.h> #include "sysfs.h" - -static struct vfsmount *sysfs_mnt; -struct kmem_cache *sysfs_dir_cachep; - -static const struct super_operations sysfs_ops = { - .statfs = simple_statfs, - .drop_inode = generic_delete_inode, - .evict_inode = sysfs_evict_inode, -}; - -struct sysfs_dirent sysfs_root = { - .s_name = "", - .s_count = ATOMIC_INIT(1), - .s_flags = SYSFS_DIR | (KOBJ_NS_TYPE_NONE << SYSFS_NS_TYPE_SHIFT), - .s_mode = S_IFDIR | S_IRUGO | S_IXUGO, - .s_ino = 1, -}; - -static int sysfs_fill_super(struct super_block *sb, void *data, int silent) -{ - struct inode *inode; - struct dentry *root; - - sb->s_blocksize = PAGE_CACHE_SIZE; - sb->s_blocksize_bits = PAGE_CACHE_SHIFT; - sb->s_magic = SYSFS_MAGIC; - sb->s_op = &sysfs_ops; - sb->s_time_gran = 1; - - /* get root inode, initialize and unlock it */ - mutex_lock(&sysfs_mutex); - inode = sysfs_get_inode(sb, &sysfs_root); - mutex_unlock(&sysfs_mutex); - if (!inode) { - pr_debug("sysfs: could not get root inode\n"); - return -ENOMEM; - } - - /* instantiate and link root dentry */ - root = d_make_root(inode); - if (!root) { - pr_debug("%s: could not get root dentry!\n", __func__); - return -ENOMEM; - } - root->d_fsdata = &sysfs_root; - sb->s_root = root; - sb->s_d_op = &sysfs_dentry_ops; - return 0; -} - -static int sysfs_test_super(struct super_block *sb, void *data) -{ - struct sysfs_super_info *sb_info = sysfs_info(sb); - struct sysfs_super_info *info = data; - enum kobj_ns_type type; - int found = 1; - - for (type = KOBJ_NS_TYPE_NONE; type < KOBJ_NS_TYPES; type++) { - if (sb_info->ns[type] != info->ns[type]) - found = 0; - } - return found; -} - -static int sysfs_set_super(struct super_block *sb, void *data) -{ - int error; - error = set_anon_super(sb, data); - if (!error) - sb->s_fs_info = data; - return error; -} - -static void free_sysfs_super_info(struct sysfs_super_info *info) -{ - int type; - for (type = KOBJ_NS_TYPE_NONE; type < KOBJ_NS_TYPES; type++) - kobj_ns_drop(type, info->ns[type]); - kfree(info); -} +static struct kernfs_root *sysfs_root; +struct kernfs_node *sysfs_root_kn; static struct dentry *sysfs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { - struct sysfs_super_info *info; - enum kobj_ns_type type; - 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)) return ERR_PTR(-EPERM); - for (type = KOBJ_NS_TYPE_NONE; type < KOBJ_NS_TYPES; type++) { - if (!kobj_ns_current_may_mount(type)) - return ERR_PTR(-EPERM); - } - } - - info = kzalloc(sizeof(*info), GFP_KERNEL); - if (!info) - return ERR_PTR(-ENOMEM); - - for (type = KOBJ_NS_TYPE_NONE; type < KOBJ_NS_TYPES; type++) - info->ns[type] = kobj_ns_grab_current(type); - - 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); - if (IS_ERR(sb)) - return ERR_CAST(sb); - if (!sb->s_root) { - error = sysfs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0); - if (error) { - deactivate_locked_super(sb); - return ERR_PTR(error); - } - sb->s_flags |= MS_ACTIVE; + if (!kobj_ns_current_may_mount(KOBJ_NS_TYPE_NET)) + return ERR_PTR(-EPERM); } - return dget(sb->s_root); + 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; } static void sysfs_kill_sb(struct super_block *sb) { - struct sysfs_super_info *info = sysfs_info(sb); - /* Remove the superblock from fs_supers/s_instances - * so we can't find it, before freeing sysfs_super_info. - */ - kill_anon_super(sb); - free_sysfs_super_info(info); + void *ns = (void *)kernfs_super_ns(sb); + + kernfs_kill_sb(sb); + kobj_ns_drop(KOBJ_NS_TYPE_NET, ns); } static struct file_system_type sysfs_fs_type = { @@ -165,48 +60,19 @@ static struct file_system_type sysfs_fs_type = { int __init sysfs_init(void) { - int err = -ENOMEM; + int err; - sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache", - sizeof(struct sysfs_dirent), - 0, 0, NULL); - if (!sysfs_dir_cachep) - goto out; + sysfs_root = kernfs_create_root(NULL, NULL); + if (IS_ERR(sysfs_root)) + return PTR_ERR(sysfs_root); - err = sysfs_inode_init(); - if (err) - goto out_err; + sysfs_root_kn = sysfs_root->kn; err = register_filesystem(&sysfs_fs_type); - if (!err) { - sysfs_mnt = kern_mount(&sysfs_fs_type); - if (IS_ERR(sysfs_mnt)) { - printk(KERN_ERR "sysfs: could not mount!\n"); - err = PTR_ERR(sysfs_mnt); - sysfs_mnt = NULL; - unregister_filesystem(&sysfs_fs_type); - goto out_err; - } - } else - goto out_err; -out: - return err; -out_err: - kmem_cache_destroy(sysfs_dir_cachep); - sysfs_dir_cachep = NULL; - goto out; -} - -#undef sysfs_get -struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd) -{ - return __sysfs_get(sd); -} -EXPORT_SYMBOL_GPL(sysfs_get); + if (err) { + kernfs_destroy_root(sysfs_root); + return err; + } -#undef sysfs_put -void sysfs_put(struct sysfs_dirent *sd) -{ - __sysfs_put(sd); + return 0; } -EXPORT_SYMBOL_GPL(sysfs_put); |