From 73071f0ce491688137ce5d8d8965416b43cfde4d Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Tue, 23 Aug 2016 17:21:30 +0200
Subject: [PATCH] btrfs-progs: build: extend convert options

Add --with-convert[=VALUE] option to configure. Accepts ext2, auto, yes,
or no, but will be extended to more in the future. The configure-time
defines are not used in the code, ext2 is built-in unconditionally.

Signed-off-by: David Sterba <dsterba@suse.com>
---
 Makefile.in     |  2 ++
 btrfs-convert.c |  1 +
 configure.ac    | 45 ++++++++++++++++++++++++++++++++++++++-------
 3 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/Makefile.in b/Makefile.in
index 1928a4ef..5c0c0d06 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -40,6 +40,7 @@ RMDIR = @RMDIR@
 INSTALL = @INSTALL@
 DISABLE_DOCUMENTATION = @DISABLE_DOCUMENTATION@
 DISABLE_BTRFSCONVERT = @DISABLE_BTRFSCONVERT@
+BTRFSCONVERT_EXT2 = @BTRFSCONVERT_EXT2@
 
 EXTRA_CFLAGS :=
 EXTRA_LDFLAGS :=
@@ -166,6 +167,7 @@ endif
 # external libs required by various binaries; for btrfs-foo,
 # specify btrfs_foo_libs = <list of libs>; see $($(subst...)) rules below
 btrfs_convert_libs = @EXT2FS_LIBS@ @COM_ERR_LIBS@
+btrfs_convert_cflags = -DBTRFSCONVERT_EXT2=$(BTRFSCONVERT_EXT2)
 btrfs_fragments_libs = -lgd -lpng -ljpeg -lfreetype
 btrfs_debug_tree_objects = cmds-inspect-dump-tree.o
 btrfs_show_super_objects = cmds-inspect-dump-super.o
diff --git a/btrfs-convert.c b/btrfs-convert.c
index b34a413d..17ea3685 100644
--- a/btrfs-convert.c
+++ b/btrfs-convert.c
@@ -37,6 +37,7 @@
 #include "crc32c.h"
 #include "utils.h"
 #include "task-utils.h"
+
 #include <ext2fs/ext2_fs.h>
 #include <ext2fs/ext2fs.h>
 #include <ext2fs/ext2_ext_attr.h>
diff --git a/configure.ac b/configure.ac
index 901d4347..97e89f23 100644
--- a/configure.ac
+++ b/configure.ac
@@ -104,13 +104,44 @@ AC_ARG_ENABLE([convert],
 AS_IF([test "x$enable_convert" = xyes], [DISABLE_BTRFSCONVERT=0], [DISABLE_BTRFSCONVERT=1])
 AC_SUBST([DISABLE_BTRFSCONVERT])
 
+AC_ARG_WITH([convert],
+	    AS_HELP_STRING([[[]--with-convert[[=auto]]]], [built-in filesystems for convert (default: auto)
+supported (comma separated list): ext2]),
+  [], [with_convert=auto]
+)
+
+if test "$with_convert" = "yes"; then
+	with_convert=auto
+fi
+
+if test "$with_convert" = "no"; then
+	with_convert=
+fi
+
+convertfs=
+BTRFSCONVERT_EXT2=0
 if test "x$enable_convert" = xyes; then
-	PKG_CHECK_MODULES(EXT2FS, [ext2fs >= 1.42],,
-		[PKG_CHECK_MODULES(EXT2FS, [ext2fs],
-			[AC_DEFINE([HAVE_OLD_E2FSPROGS], [1],
-				  [E2fsprogs does not support BIGALLOC])]
-			)])
-	PKG_CHECK_MODULES(COM_ERR, [com_err])
+	if test "x$with_convert" = "xauto" || echo "$with_convert" | grep -q "ext2"; then
+		PKG_CHECK_MODULES(EXT2FS, [ext2fs >= 1.42],,
+			[PKG_CHECK_MODULES(EXT2FS, [ext2fs],
+				[AC_DEFINE([HAVE_OLD_E2FSPROGS], [1],
+					  [E2fsprogs does not support BIGALLOC])]
+				)])
+		PKG_CHECK_MODULES(COM_ERR, [com_err])
+		convertfs="${convertfs:+$convertfs,}ext2"
+		BTRFSCONVERT_EXT2=1
+	fi
+fi
+AC_SUBST([BTRFSCONVERT_EXT2])
+
+# catch typos
+tmp=$(echo "$with_convert" | sed -e 's/auto//' | sed -e 's/ext2//' | sed -e 's/,\+/,/')
+if ! test "x$tmp" = "x"; then
+	AC_MSG_ERROR([unknown tokens for --with-convert: $tmp])
+fi
+
+if test "$DISABLE_BTRFSCONVERT" = 0 && test "x$convertfs" = "x"; then
+	AC_MSG_ERROR([no filesystems for convert, use --disable-convert instead])
 fi
 
 AX_CHECK_DEFINE([linux/fiemap.h], [FIEMAP_EXTENT_SHARED], [],
@@ -176,7 +207,7 @@ AC_MSG_RESULT([
 
 	documentation:     ${enable_documentation}
 	backtrace support: ${enable_backtrace}
-	btrfs-convert:     ${enable_convert}
+	btrfs-convert:     ${enable_convert} ${convertfs:+($convertfs)}
 
 	Type 'make' to compile.
 ])