1 files changed, 25 insertions, 33 deletions

diff --git a/fs/proc/root.c b/fs/proc/root.c
index 4258384ed22d..d6c3b416529b 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -28,32 +28,22 @@ static int proc_test_super(struct super_block *sb, void *data)
 
 static int proc_set_super(struct super_block *sb, void *data)
 {
-        struct pid_namespace *ns;
-
-        ns = (struct pid_namespace *)data;
-        sb->s_fs_info = get_pid_ns(ns);
-        return set_anon_super(sb, NULL);
+        int err = set_anon_super(sb, NULL);
+        if (!err) {
+                struct pid_namespace *ns = (struct pid_namespace *)data;
+                sb->s_fs_info = get_pid_ns(ns);
+        }
+        return err;
 }
 
-static int proc_get_sb(struct file_system_type *fs_type,
-        int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *proc_mount(struct file_system_type *fs_type,
+        int flags, const char *dev_name, void *data)
 {
         int err;
         struct super_block *sb;
         struct pid_namespace *ns;
         struct proc_inode *ei;
 
-        if (proc_mnt) {
-                /* Seed the root directory with a pid so it doesn't need
-                 * to be special in base.c.  I would do this earlier but
-                 * the only task alive when /proc is mounted the first time
-                 * is the init_task and it doesn't have any pids.
-                 */
-                ei = PROC_I(proc_mnt->mnt_sb->s_root->d_inode);
-                if (!ei->pid)
-                        ei->pid = find_get_pid(1);
-        }
-
         if (flags & MS_KERNMOUNT)
                 ns = (struct pid_namespace *)data;
         else
@@ -61,29 +51,27 @@ static int proc_get_sb(struct file_system_type *fs_type,
 
         sb = sget(fs_type, proc_test_super, proc_set_super, ns);
         if (IS_ERR(sb))
-                return PTR_ERR(sb);
+                return ERR_CAST(sb);
 
         if (!sb->s_root) {
                 sb->s_flags = flags;
                 err = proc_fill_super(sb);
                 if (err) {
                         deactivate_locked_super(sb);
-                        return err;
-                }
-
-                ei = PROC_I(sb->s_root->d_inode);
-                if (!ei->pid) {
-                        rcu_read_lock();
-                        ei->pid = get_pid(find_pid_ns(1, ns));
-                        rcu_read_unlock();
+                        return ERR_PTR(err);
                 }
 
                 sb->s_flags |= MS_ACTIVE;
-                ns->proc_mnt = mnt;
         }
 
-        simple_set_mnt(mnt, sb);
-        return 0;
+        ei = PROC_I(sb->s_root->d_inode);
+        if (!ei->pid) {
+                rcu_read_lock();
+                ei->pid = get_pid(find_pid_ns(1, ns));
+                rcu_read_unlock();
+        }
+
+        return dget(sb->s_root);
 }
 
 static void proc_kill_sb(struct super_block *sb)
@@ -97,24 +85,26 @@ static void proc_kill_sb(struct super_block *sb)
 
 static struct file_system_type proc_fs_type = {
         .name           = "proc",
-        .get_sb         = proc_get_sb,
+        .mount          = proc_mount,
         .kill_sb        = proc_kill_sb,
 };
 
 void __init proc_root_init(void)
 {
+        struct vfsmount *mnt;
         int err;
 
         proc_init_inodecache();
         err = register_filesystem(&proc_fs_type);
         if (err)
                 return;
-        proc_mnt = kern_mount_data(&proc_fs_type, &init_pid_ns);
-        if (IS_ERR(proc_mnt)) {
+        mnt = kern_mount_data(&proc_fs_type, &init_pid_ns);
+        if (IS_ERR(mnt)) {
                 unregister_filesystem(&proc_fs_type);
                 return;
         }
 
+        init_pid_ns.proc_mnt = mnt;
         proc_symlink("mounts", NULL, "self/mounts");
 
         proc_net_init();
@@ -179,6 +169,7 @@ static int proc_root_readdir(struct file * filp,
 static const struct file_operations proc_root_operations = {
         .read            = generic_read_dir,
         .readdir         = proc_root_readdir,
+        .llseek         = default_llseek,
 };
 
 /*
@@ -212,6 +203,7 @@ int pid_ns_prepare_proc(struct pid_namespace *ns)
         if (IS_ERR(mnt))
                 return PTR_ERR(mnt);
 
+        ns->proc_mnt = mnt;
         return 0;
 }