[Libguestfs] [PATCH v2 4/4] v2v: reuse main guestfs for virtio win drivers iso
If we're given an ISO image as the source of virtio windows drivers, and
the backend supports hot-adding drives, reuse the same guestfs handle
that is open for accessing the guest being inspected, rather than
creating a new one (which would run another virtual machine instance and
is fairly resource-intensive).
Signed-off-by: Roman Kagan <rkagan(a)virtuozzo.com>
---
changes since v1:
- updated usage of string functions
- add missing and remove excessive parentheses
- preserve support for backends with no hot-add capability
v2v/convert_windows.ml | 38 +++++++++++++++++++++++++++++---------
1 file changed, 29 insertions(+), 9 deletions(-)
diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml
index cfa5474..5fd8bb6 100644
--- a/v2v/convert_windows.ml
+++ b/v2v/convert_windows.ml
@@ -294,13 +294,25 @@ echo uninstalling Xen PV driver
)
else if is_regular_file virtio_win then (
try
- let g2 = new Guestfs.guestfs () in
- if trace () then g2#set_trace true;
- if verbose () then g2#set_verbose true;
- g2#add_drive_opts virtio_win ~readonly:true;
- g2#launch ();
- let vio_root = "/" in
- g2#mount_ro "/dev/sda" vio_root;
+ let label = "viowin" in
+ let vio_root = "/virtio-win-iso" in
+ let g2 =
+ (* not all backends support hot-adding drives; create an extra
+ * guestfs handle in that case *)
+ try
+ g#add_drive_opts virtio_win ~readonly:true ~label:label;
+ g
+ with Guestfs.Error msg -> (
+ let g2 = new Guestfs.guestfs () in
+ if trace () then g2#set_trace true;
+ if verbose () then g2#set_verbose true;
+ g2#add_drive_opts virtio_win ~readonly:true ~label:label;
+ g2#launch ();
+ g2
+ ) in
+
+ g2#mkmountpoint vio_root;
+ g2#mount_ro ("/dev/disk/guestfs" // label) vio_root;
let paths = g2#find vio_root in
Array.iter (
fun path ->
@@ -315,10 +327,18 @@ echo uninstalling Xen PV driver
printf "Copying virtio driver bits: '%s:%s' ->
'%s'\n"
virtio_win path target;
- g#write target (g2#read_file source)
+ if (g2 == g) then
+ g#cp source target
+ else
+ g#write target (g2#read_file source)
)
) paths;
- g2#close()
+ g2#umount vio_root;
+ g2#rmmountpoint vio_root;
+ if (g2 == g) then
+ g2#remove_drive label
+ else
+ g2#close()
with Guestfs.Error msg ->
error (f_"%s: cannot open virtio-win ISO file: %s") virtio_win msg
)
--
2.4.3