raw-posix: support discard on more filesystems
Linux 2.6.38 introduced the filesystem independent interface to
deallocate part of a file. As of Linux 3.7, btrfs, ext4, ocfs2,
tmpfs and xfs support it.
Even though the system calls here are in practice issued on Linux,
the code is structured to allow plugging in alternatives for other Unix
variants. EOPNOTSUPP is used unconditionally in this patch, but it is
supported in both OpenBSD and Mac OS X since forever (see for example
http://lists.debian.org/debian-glibc/2006/02/msg00337.html).
Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/configure b/configure
index c908f66..40d250c 100755
--- a/configure
+++ b/configure
@@ -2581,6 +2581,22 @@
fallocate=yes
fi
+# check for fallocate hole punching
+fallocate_punch_hole=no
+cat > $TMPC << EOF
+#include <fcntl.h>
+#include <linux/falloc.h>
+
+int main(void)
+{
+ fallocate(0, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, 0, 0);
+ return 0;
+}
+EOF
+if compile_prog "" "" ; then
+ fallocate_punch_hole=yes
+fi
+
# check for sync_file_range
sync_file_range=no
cat > $TMPC << EOF
@@ -3490,6 +3506,9 @@
if test "$fallocate" = "yes" ; then
echo "CONFIG_FALLOCATE=y" >> $config_host_mak
fi
+if test "$fallocate_punch_hole" = "yes" ; then
+ echo "CONFIG_FALLOCATE_PUNCH_HOLE=y" >> $config_host_mak
+fi
if test "$sync_file_range" = "yes" ; then
echo "CONFIG_SYNC_FILE_RANGE=y" >> $config_host_mak
fi
