pstore: Create a convenient mount point for pstore

Using /dev/pstore as a mount point for the pstore filesystem is slightly
awkward.  We don't normally mount filesystems in /dev/ and the /dev/pstore
file isn't created automatically by anything.  While this method will
still work, we can create a persistent mount point in sysfs.  This will
put pstore on par with things like cgroups and efivarfs.

Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 67de74c..e4bcb2c 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -418,9 +418,25 @@
 	.kill_sb	= pstore_kill_sb,
 };
 
+static struct kobject *pstore_kobj;
+
 static int __init init_pstore_fs(void)
 {
-	return register_filesystem(&pstore_fs_type);
+	int err = 0;
+
+	/* Create a convenient mount point for people to access pstore */
+	pstore_kobj = kobject_create_and_add("pstore", fs_kobj);
+	if (!pstore_kobj) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = register_filesystem(&pstore_fs_type);
+	if (err < 0)
+		kobject_put(pstore_kobj);
+
+out:
+	return err;
 }
 module_init(init_pstore_fs)