libxl: fix cleanup of tap devices in libxl__device_destroy

We pass be_path to tapdisk_destroy but we've already deleted it so it
fails to read tapdisk-params. However it appears that we need to
destroy the tap device after tearing down xenstore, to avoid the leak
reported by Greg Wettstein in
<201207312141.q6VLfJje012656@wind.enjellic.com>.

So read the tapdisk-params in the cleanup transaction, before the
remove, and pass that down to destroy_tapdisk instead. tapdisk-params
may of course be NULL if the device isn't a tap device.

There is no need to tear down the tap device from
libxl__initiate_device_remove since this ultimately calls
libxl__device_destroy.

Propagate and log errors from libxl__device_destroy_tapdisk.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/tools/libxl/libxl_noblktap2.c b/tools/libxl/libxl_noblktap2.c
index 246b0de63b..5a86ed1b6a 100644
--- a/tools/libxl/libxl_noblktap2.c
+++ b/tools/libxl/libxl_noblktap2.c
@@ -28,8 +28,9 @@ char *libxl__blktap_devpath(libxl__gc *gc,
     return NULL;
 }
 
-void libxl__device_destroy_tapdisk(libxl__gc *gc, char *be_path)
+int libxl__device_destroy_tapdisk(libxl__gc *gc, const char *params)
 {
+    return 0;
 }
 
 /*