commit 6542aa9c75bcef5a549b8ac1ce34d0ec6782a3c2
author Peter Lieven <pl@kamp.de> Mon Feb 03 10:26:13 2014 +0100
committer Kevin Wolf <kwolf@redhat.com> Sun Feb 09 09:12:38 2014 +0100
tree 5591bc69ed39b7d6ca8beebe463862ac1e6308b9
parent f51062061e6adf64a879177f35ff5c6babb63e7e

block: add native support for NFS

This patch adds native support for accessing images on NFS
shares without the requirement to actually mount the entire
NFS share on the host.

NFS Images can simply be specified by an url of the form:
nfs://<host>/<export>/<filename>[?param=value[&param2=value2[&...]]]

For example:
qemu-img create -f qcow2 nfs://10.0.0.1/qemu-images/test.qcow2

You need LibNFS from Ronnie Sahlberg available at:
   git://github.com/sahlberg/libnfs.git
for this to work.

During configure it is automatically probed for libnfs and support
is enabled on-the-fly. You can forbid or enforce libnfs support
with --disable-libnfs or --enable-libnfs respectively.

Due to NFS restrictions you might need to execute your binaries
as root, allow them to open priviledged ports (<1024) or specify
insecure option on the NFS server.

For additional information on ROOT vs. non-ROOT operation and URL
format + parameters see:
   https://raw.github.com/sahlberg/libnfs/master/README

Supported by qemu are the uid, gid and tcp-syncnt URL parameters.

LibNFS currently support NFS version 3 only.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

configure

diff --git a/configure b/configure
index 236764a..5b20ce6 100755
--- a/configure
+++ b/configure
@@ -251,6 +251,7 @@
 win_sdk="no"
 want_tools="yes"
 libiscsi=""
+libnfs=""
 coroutine=""
 coroutine_pool=""
 seccomp=""
@@ -840,6 +841,10 @@
   ;;
   --enable-libiscsi) libiscsi="yes"
   ;;
+  --disable-libnfs) libnfs="no"
+  ;;
+  --enable-libnfs) libnfs="yes"
+  ;;
   --enable-profiler) profiler="yes"
   ;;
   --disable-cocoa) cocoa="no"
@@ -1229,6 +1234,8 @@
   --enable-rbd             enable building the rados block device (rbd)
   --disable-libiscsi       disable iscsi support
   --enable-libiscsi        enable iscsi support
+  --disable-libnfs         disable nfs support
+  --enable-libnfs          enable nfs support
   --disable-smartcard-nss  disable smartcard nss support
   --enable-smartcard-nss   enable smartcard nss support
   --disable-libusb         disable libusb (for usb passthrough)
@@ -3600,6 +3607,20 @@
   CFLAGS="-O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 $CFLAGS"
 fi
 
+##########################################
+# Do we have libnfs
+if test "$libnfs" != "no" ; then
+  if $pkg_config --atleast-version=1.9.2 libnfs; then
+    libnfs="yes"
+    libnfs_libs=$($pkg_config --libs libnfs)
+    LIBS="$LIBS $libnfs_libs"
+  else
+    if test "$libnfs" = "yes" ; then
+      feature_not_found "libnfs"
+    fi
+    libnfs="no"
+  fi
+fi
 
 # Disable zero malloc errors for official releases unless explicitly told to
 # enable/disable
@@ -3829,6 +3850,7 @@
 else
 echo "libiscsi support  $libiscsi"
 fi
+echo "libnfs support    $libnfs"
 echo "build guest agent $guest_agent"
 echo "QGA VSS support   $guest_agent_with_vss"
 echo "seccomp support   $seccomp"
@@ -4165,6 +4187,10 @@
   fi
 fi
 
+if test "$libnfs" = "yes" ; then
+  echo "CONFIG_LIBNFS=y" >> $config_host_mak
+fi
+
 if test "$seccomp" = "yes"; then
   echo "CONFIG_SECCOMP=y" >> $config_host_mak
 fi