1 files changed, 25 insertions, 159 deletions

diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 834ec2cdb7a3..6211230814fd 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);