Merge tag 'v3.12-rc4' into next

Merge with mainline to bring in changes to input subsystem that were
committed through other trees.

1 files changed, 45 insertions, 0 deletions

diff --git a/init/do_mounts.c b/init/do_mounts.c
index 816014c4627e..a51cddc2ff8c 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -26,6 +26,8 @@
 #include <linux/async.h>
 #include <linux/fs_struct.h>
 #include <linux/slab.h>
+#include <linux/ramfs.h>
+#include <linux/shmem_fs.h>
 
 #include <linux/nfs_fs.h>
 #include <linux/nfs_fs_sb.h>
@@ -588,3 +590,46 @@ out:
 	sys_mount(".", "/", NULL, MS_MOVE, NULL);
 	sys_chroot(".");
 }
+
+static bool is_tmpfs;
+static struct dentry *rootfs_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
+{
+	static unsigned long once;
+	void *fill = ramfs_fill_super;
+
+	if (test_and_set_bit(0, &once))
+		return ERR_PTR(-ENODEV);
+
+	if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
+		fill = shmem_fill_super;
+
+	return mount_nodev(fs_type, flags, data, fill);
+}
+
+static struct file_system_type rootfs_fs_type = {
+	.name		= "rootfs",
+	.mount		= rootfs_mount,
+	.kill_sb	= kill_litter_super,
+};
+
+int __init init_rootfs(void)
+{
+	int err = register_filesystem(&rootfs_fs_type);
+
+	if (err)
+		return err;
+
+	if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
+		(!root_fs_names || strstr(root_fs_names, "tmpfs"))) {
+		err = shmem_init();
+		is_tmpfs = true;
+	} else {
+		err = init_ramfs_fs();
+	}
+
+	if (err)
+		unregister_filesystem(&rootfs_fs_type);
+
+	return err;
+}