vfs: umount_tree() might be called on subtree that had never made it

[firefly-linux-kernel-4.4.55.git] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index fe59bd145d214b0157b75dd7b441c91e24dcb56c..b3d8f51c6fa379794acd9ef622a7f81c05a4e5a4 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1048,15 +1048,12 @@ static int show_mountinfo(struct seq_file *m, void *v)
        if (err)
                goto out;
        seq_putc(m, ' ');
-       seq_path_root(m, &mnt_path, &root, " \t\n\\");
-       if (root.mnt != p->root.mnt || root.dentry != p->root.dentry) {
-               /*
-                * Mountpoint is outside root, discard that one.  Ugly,
-                * but less so than trying to do that in iterator in a
-                * race-free way (due to renames).
-                */
-               return SEQ_SKIP;
-       }
+
+       /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
+       err = seq_path_root(m, &mnt_path, &root, " \t\n\\");
+       if (err)
+               goto out;
+
        seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");
        show_mnt_opts(m, mnt);
 
@@ -1109,6 +1106,7 @@ static int show_vfsstat(struct seq_file *m, void *v)
 
        /* device */
        if (mnt->mnt_sb->s_op->show_devname) {
+               seq_puts(m, "device ");
                err = mnt->mnt_sb->s_op->show_devname(m, mnt);
        } else {
                if (mnt->mnt_devname) {
@@ -1246,8 +1244,9 @@ void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill)
                list_del_init(&p->mnt_expire);
                list_del_init(&p->mnt_list);
                __touch_mnt_namespace(p->mnt_ns);
+               if (p->mnt_ns)
+                       __mnt_make_shortterm(p);
                p->mnt_ns = NULL;
-               __mnt_make_shortterm(p);
                list_del_init(&p->mnt_child);
                if (p->mnt_parent != p) {
                        p->mnt_parent->mnt_ghosts++;
@@ -1757,7 +1756,7 @@ static int do_loopback(struct path *path, char *old_name,
                return err;
        if (!old_name || !*old_name)
                return -EINVAL;
-       err = kern_path(old_name, LOOKUP_FOLLOW, &old_path);
+       err = kern_path(old_name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &old_path);
        if (err)
                return err;
 
@@ -2724,3 +2723,8 @@ struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
        return vfs_kern_mount(type, MS_KERNMOUNT, type->name, data);
 }
 EXPORT_SYMBOL_GPL(kern_mount_data);
+
+bool our_mnt(struct vfsmount *mnt)
+{
+       return check_mnt(mnt);
+}