erofs-utils: switch other source files into MIT license

Let's switch other source files to MIT license since we're absolutely
not working on secret rocket science, so licenses should not be
a bottleneck to innovation in the Cloud Native and AI era.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Hongbo Li <lihongbo22@huawei.com>
Reviewed-by: Chunhai Guo <guochunhai@vivo.com>
Reviewed-by: Yifan Zhao <zhaoyifan28@huawei.com>
Link: https://lore.kernel.org/r/20260402060907.2268323-2-hsiangkao@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
diff --git a/COPYING b/COPYING
index e781cc2..81aee79 100644
--- a/COPYING
+++ b/COPYING
@@ -3,13 +3,13 @@
  - most liberofs files in `lib` and `include` directories
    use GPL-2.0+ OR MIT dual license;
 
- - all other files use GPL-2.0+ license, unless
-   explicitly stated otherwise.
+ - all other files use MIT license, unless explicitly stated
+   otherwise.
 
 Relevant licenses can be found in the LICENSES directory.
 
-This model is selected to emphasize that
-files in `lib` and `include` directories are designed to be included in
-3rd-party applications, while all other files are intended to be used
-"as is", as part of their intended scenarios, with no intention to
-support 3rd-party integration use cases.
+This model is selected to emphasize that erofs-utils can be integrated
+into various ecosystems as much as possible.
+
+However, liberofs should be GPL-2.0+ OR MIT dual license since some
+parts can be shared with the Linux kernel.
diff --git a/Makefile.am b/Makefile.am
index 7cb93a6..e79222e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0+
+# SPDX-License-Identifier: MIT
 
 ACLOCAL_AMFLAGS = -I m4
 
diff --git a/autogen.sh b/autogen.sh
index fd81db4..89c510c 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# SPDX-License-Identifier: GPL-2.0+
+# SPDX-License-Identifier: MIT
 
 aclocal && \
 autoheader && \
diff --git a/contrib/Makefile.am b/contrib/Makefile.am
index 4eb7abe..5bedb94 100644
--- a/contrib/Makefile.am
+++ b/contrib/Makefile.am
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0+
+# SPDX-License-Identifier: MIT
 # Makefile.am
 
 AUTOMAKE_OPTIONS	= foreign
diff --git a/contrib/stress.c b/contrib/stress.c
index 0ef8c67..65773bc 100644
--- a/contrib/stress.c
+++ b/contrib/stress.c
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+// SPDX-License-Identifier: MIT
 /*
  * stress test for EROFS filesystem
  *
diff --git a/dump/Makefile.am b/dump/Makefile.am
index c2e0c74..2611fd2 100644
--- a/dump/Makefile.am
+++ b/dump/Makefile.am
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0+
+# SPDX-License-Identifier: MIT
 # Makefile.am
 
 AUTOMAKE_OPTIONS = foreign
diff --git a/dump/main.c b/dump/main.c
index 78c50d5..6c7258a 100644
--- a/dump/main.c
+++ b/dump/main.c
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+// SPDX-License-Identifier: MIT
 /*
  * Copyright (C) 2021-2022 HUAWEI, Inc.
  *             http://www.huawei.com/
diff --git a/fsck/Makefile.am b/fsck/Makefile.am
index 488b401..8eebadd 100644
--- a/fsck/Makefile.am
+++ b/fsck/Makefile.am
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0+
+# SPDX-License-Identifier: MIT
 # Makefile.am
 
 AUTOMAKE_OPTIONS = foreign
diff --git a/fsck/main.c b/fsck/main.c
index 16a354f..21ada19 100644
--- a/fsck/main.c
+++ b/fsck/main.c
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+// SPDX-License-Identifier: MIT
 /*
  * Copyright 2021 Google LLC
  * Author: Daeho Jeong <daehojeong@google.com>
diff --git a/fuse/Makefile.am b/fuse/Makefile.am
index 1e8f518..9fe5608 100644
--- a/fuse/Makefile.am
+++ b/fuse/Makefile.am
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0+
+# SPDX-License-Identifier: MIT
 
 AUTOMAKE_OPTIONS = foreign
 noinst_HEADERS = $(top_srcdir)/fuse/macosx.h
diff --git a/fuse/macosx.h b/fuse/macosx.h
index 81ac47f..4bb4bb7 100644
--- a/fuse/macosx.h
+++ b/fuse/macosx.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
+/* SPDX-License-Identifier: MIT */
 #ifdef __APPLE__
 #undef LIST_HEAD
 #endif
diff --git a/fuse/main.c b/fuse/main.c
index b634782..40f8684 100644
--- a/fuse/main.c
+++ b/fuse/main.c
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+// SPDX-License-Identifier: MIT
 /*
  * Created by Li Guifu <blucerlee@gmail.com>
  * Lowlevel added by Li Yiyan <lyy0627@sjtu.edu.cn>
diff --git a/man/Makefile.am b/man/Makefile.am
index b9b5989..88bf3a1 100644
--- a/man/Makefile.am
+++ b/man/Makefile.am
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0+
+# SPDX-License-Identifier: MIT
 
 dist_man_MANS = mkfs.erofs.1 dump.erofs.1 fsck.erofs.1
 
diff --git a/mkfs/Makefile.am b/mkfs/Makefile.am
index aaefc11..386455a 100644
--- a/mkfs/Makefile.am
+++ b/mkfs/Makefile.am
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0+
+# SPDX-License-Identifier: MIT
 
 AUTOMAKE_OPTIONS = foreign
 bin_PROGRAMS     = mkfs.erofs
diff --git a/mkfs/main.c b/mkfs/main.c
index eb13aba..5006f76 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+// SPDX-License-Identifier: MIT
 /*
  * Copyright (C) 2018-2019 HUAWEI, Inc.
  *             http://www.huawei.com/
diff --git a/mount/Makefile.am b/mount/Makefile.am
index 7f6efd8..637029d 100644
--- a/mount/Makefile.am
+++ b/mount/Makefile.am
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0+
+# SPDX-License-Identifier: MIT
 # Makefile.am
 
 AUTOMAKE_OPTIONS = foreign
diff --git a/mount/main.c b/mount/main.c
index b6a2dec..e09e585 100644
--- a/mount/main.c
+++ b/mount/main.c
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+// SPDX-License-Identifier: MIT
 #define _GNU_SOURCE
 #include <dirent.h>
 #include <fcntl.h>
diff --git a/scripts/get-version-number b/scripts/get-version-number
index d216b7a..484baeb 100755
--- a/scripts/get-version-number
+++ b/scripts/get-version-number
@@ -1,5 +1,5 @@
 #!/bin/sh
-# SPDX-License-Identifier: GPL-2.0
+# SPDX-License-Identifier: MIT
 
 scm_version()
 {