libfsimage: add ext4 support for CentOS 5.x

CentOS 5.x forked e2fs ext4 support into a different package called
e4fs, and so headers and library names changed from ext2fs to ext4fs.
Check if ext4fs/ext2fs.h and -lext4fs work, and use that instead of
ext2fs to build libfsimage. This patch assumes that if the ext4fs
library is present it should always be used instead of ext2fs.

This patch includes a rework of the ext2fs check, a new ext4fs check
and a minor modification in libfsimage to use the correct library.

Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>

xen-unstable changeset: 25895:98e1ba6a672a
Backport-requested-by: Ian Campbell <Ian.Campbell@citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>

8 files changed, 104 insertions, 9 deletions

diff --git a/config/Tools.mk.in b/config/Tools.mk.in
index 21ad0ef270..a6ecf48dfd 100644
--- a/config/Tools.mk.in
+++ b/config/Tools.mk.in
@@ -57,5 +57,5 @@ CONFIG_SYSTEM_LIBAIO:= @system_aio@
 ZLIB                := @zlib@
 CONFIG_LIBICONV     := @libiconv@
 CONFIG_GCRYPT       := @libgcrypt@
-CONFIG_EXT2FS       := @libext2fs@
+EXTFS_LIBS          := @EXTFS_LIBS@
 CURSES_LIBS         := @CURSES_LIBS@
diff --git a/tools/config.h.in b/tools/config.h.in
index bc1ed1057b..6d67503de7 100644
--- a/tools/config.h.in
+++ b/tools/config.h.in
@@ -42,6 +42,9 @@
 /* Define curses header to use */
 #undef INCLUDE_CURSES_H
 
+/* Define extfs header to use */
+#undef INCLUDE_EXTFS_H
+
 /* libutil header file name */
 #undef INCLUDE_LIBUTIL_H
 
diff --git a/tools/configure b/tools/configure
index 8368e2cff4..d68d985bed 100755
--- a/tools/configure
+++ b/tools/configure
@@ -603,7 +603,7 @@ PTHREAD_LIBS
 PTHREAD_LDFLAGS
 PTHREAD_CFLAGS
 libgcrypt
-libext2fs
+EXTFS_LIBS
 system_aio
 zlib
 glib_LIBS
@@ -2389,6 +2389,8 @@ case $host_os in *\ *) host_os=`echo "$host_os" | sed 's/ /-/g'`;; esac
 
 
 
+
+
 # Enable/disable options
 
 # Check whether --enable-githttp was given.
@@ -6325,6 +6327,10 @@ else
   as_fn_error $? "Could not find libcrypto" "$LINENO" 5
 fi
 
+
+ac_fn_c_check_header_mongrel "$LINENO" "ext2fs/ext2fs.h" "ac_cv_header_ext2fs_ext2fs_h" "$ac_includes_default"
+if test "x$ac_cv_header_ext2fs_ext2fs_h" = x""yes; then :
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ext2fs_open2 in -lext2fs" >&5
 $as_echo_n "checking for ext2fs_open2 in -lext2fs... " >&6; }
 if test "${ac_cv_lib_ext2fs_ext2fs_open2+set}" = set; then :
@@ -6362,10 +6368,70 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_ext2fs_ext2fs_open2" >&5
 $as_echo "$ac_cv_lib_ext2fs_ext2fs_open2" >&6; }
 if test "x$ac_cv_lib_ext2fs_ext2fs_open2" = x""yes; then :
-  libext2fs="y"
+
+
+$as_echo "#define INCLUDE_EXTFS_H <ext2fs/ext2fs.h>" >>confdefs.h
+
+    EXTFS_LIBS="-lext2fs"
+
+fi
+
+
+fi
+
+
+ac_fn_c_check_header_mongrel "$LINENO" "ext4fs/ext2fs.h" "ac_cv_header_ext4fs_ext2fs_h" "$ac_includes_default"
+if test "x$ac_cv_header_ext4fs_ext2fs_h" = x""yes; then :
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for ext2fs_open2 in -lext4fs" >&5
+$as_echo_n "checking for ext2fs_open2 in -lext4fs... " >&6; }
+if test "${ac_cv_lib_ext4fs_ext2fs_open2+set}" = set; then :
+  $as_echo_n "(cached) " >&6
 else
-  libext2fs="n"
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lext4fs  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char ext2fs_open2 ();
+int
+main ()
+{
+return ext2fs_open2 ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_ext4fs_ext2fs_open2=yes
+else
+  ac_cv_lib_ext4fs_ext2fs_open2=no
 fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_ext4fs_ext2fs_open2" >&5
+$as_echo "$ac_cv_lib_ext4fs_ext2fs_open2" >&6; }
+if test "x$ac_cv_lib_ext4fs_ext2fs_open2" = x""yes; then :
+
+
+$as_echo "#define INCLUDE_EXTFS_H <ext4fs/ext2fs.h>" >>confdefs.h
+
+    EXTFS_LIBS="-lext4fs"
+
+fi
+
+
+fi
+
+
 
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for gcry_md_hash_buffer in -lgcrypt" >&5
diff --git a/tools/configure.ac b/tools/configure.ac
index 703a24bf33..3b3ce42323 100644
--- a/tools/configure.ac
+++ b/tools/configure.ac
@@ -34,6 +34,7 @@ m4_include([m4/pkg.m4])
 m4_include([m4/curses.m4])
 m4_include([m4/pthread.m4])
 m4_include([m4/ptyfuncs.m4])
+m4_include([m4/extfs.m4])
 
 # Enable/disable options
 AX_ARG_DEFAULT_DISABLE([githttp], [Download GIT repositories via HTTP])
@@ -131,8 +132,7 @@ AC_SUBST(zlib)
 AC_CHECK_LIB([aio], [io_setup], [system_aio="y"], [system_aio="n"])
 AC_SUBST(system_aio)
 AC_CHECK_LIB([crypto], [MD5], [], [AC_MSG_ERROR([Could not find libcrypto])])
-AC_CHECK_LIB([ext2fs], [ext2fs_open2], [libext2fs="y"], [libext2fs="n"])
-AC_SUBST(libext2fs)
+AX_CHECK_EXTFS
 AC_CHECK_LIB([gcrypt], [gcry_md_hash_buffer], [libgcrypt="y"], [libgcrypt="n"])
 AC_SUBST(libgcrypt)
 AX_CHECK_PTHREAD
diff --git a/tools/libfsimage/Makefile b/tools/libfsimage/Makefile
index 5a506f3325..69fd18a820 100644
--- a/tools/libfsimage/Makefile
+++ b/tools/libfsimage/Makefile
@@ -3,7 +3,7 @@ include $(XEN_ROOT)/tools/Rules.mk
 
 SUBDIRS-y = common ufs reiserfs iso9660 fat zfs
 SUBDIRS-$(CONFIG_X86) += xfs
-ifeq ($(CONFIG_EXT2FS), y)
+ifneq ($(EXTFS_LIBS), )
     SUBDIRS-y += ext2fs-lib
 else
     SUBDIRS-y += ext2fs
diff --git a/tools/libfsimage/ext2fs-lib/Makefile b/tools/libfsimage/ext2fs-lib/Makefile
index 142207f63b..671fbffd73 100644
--- a/tools/libfsimage/ext2fs-lib/Makefile
+++ b/tools/libfsimage/ext2fs-lib/Makefile
@@ -4,7 +4,10 @@ LIB_SRCS-y = ext2fs-lib.c
 
 FS = ext2fs-lib
 
-FS_LIBDEPS = -lext2fs
+FS_LIBDEPS = $(EXTFS_LIBS)
+
+# Include configure output (config.h) to headers search path
+CFLAGS += -I$(XEN_ROOT)/tools
 
 .PHONY: all
 all: fs-all
diff --git a/tools/libfsimage/ext2fs-lib/ext2fs-lib.c b/tools/libfsimage/ext2fs-lib/ext2fs-lib.c
index 36a27dc028..ed471465f9 100644
--- a/tools/libfsimage/ext2fs-lib/ext2fs-lib.c
+++ b/tools/libfsimage/ext2fs-lib/ext2fs-lib.c
@@ -21,8 +21,11 @@
  * Use is subject to license terms.
  */
 
+/* Include output from configure */
+#include <config.h>
+
 #include <fsimage_plugin.h>
-#include <ext2fs/ext2fs.h>
+#include INCLUDE_EXTFS_H
 #include <errno.h>
 #include <inttypes.h>
 
diff --git a/tools/m4/extfs.m4 b/tools/m4/extfs.m4
new file mode 100644
index 0000000000..7309da978d
--- /dev/null
+++ b/tools/m4/extfs.m4
@@ -0,0 +1,20 @@
+AC_DEFUN([AX_CHECK_EXTFS], [
+AC_CHECK_HEADER([ext2fs/ext2fs.h], [
+AC_CHECK_LIB([ext2fs], [ext2fs_open2], [
+    AC_DEFINE([INCLUDE_EXTFS_H], [<ext2fs/ext2fs.h>],
+              [Define extfs header to use])
+    EXTFS_LIBS="-lext2fs"
+])
+])
+dnl This is a temporary hack for CentOS 5.x, which split the ext4 support
+dnl of ext2fs in a different package. Once CentOS 5.x is no longer supported
+dnl we can remove this.
+AC_CHECK_HEADER([ext4fs/ext2fs.h], [
+AC_CHECK_LIB([ext4fs], [ext2fs_open2], [
+    AC_DEFINE([INCLUDE_EXTFS_H], [<ext4fs/ext2fs.h>],
+              [Define extfs header to use])
+    EXTFS_LIBS="-lext4fs"
+])
+])
+AC_SUBST(EXTFS_LIBS)
+])