[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [libvirt] [PATCH 4/4] util: fix removal of callbacks in virCloseCallbacksRun



On Tue, 7 Apr 2015, Ján Tomko wrote:
On Mon, Mar 30, 2015 at 01:41:01PM +1100, Michael Chapman wrote:
The close callbacks hash are keyed by a UUID-string, but
virCloseCallbacksRun was attempting to remove them by raw UUID. This
patch ensures the callback entries are removed by UUID-string as well.

This bug could cause problems when guest migrations were abnormally aborted:

  # timeout --signal KILL 1 \
      virsh migrate example qemu+tls://remote/system \
        --verbose --compressed --live --auto-converge \
        --abort-on-error --unsafe --persistent \
        --undefinesource --copy-storage-all --xml example.xml
  Killed

  # virsh migrate example qemu+tls://remote/system \
      --verbose --compressed --live --auto-converge \
      --abort-on-error --unsafe --persistent \
      --undefinesource --copy-storage-all --xml example.xml
  error: Requested operation is not valid: domain 'example' is not being migrated

Signed-off-by: Michael Chapman <mike very puzzling org>
---
 src/util/virclosecallbacks.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/util/virclosecallbacks.c b/src/util/virclosecallbacks.c
index 4128057..b0a1a9e 100644
--- a/src/util/virclosecallbacks.c
+++ b/src/util/virclosecallbacks.c
@@ -236,6 +236,7 @@ typedef struct _virCloseCallbacksListEntry virCloseCallbacksListEntry;
 typedef virCloseCallbacksListEntry *virCloseCallbacksListEntryPtr;
 struct _virCloseCallbacksListEntry {
     unsigned char uuid[VIR_UUID_BUFLEN];
+    char uuidstr[VIR_UUID_STRING_BUFLEN];

We shouldn't be storing the uuid twice.

OK.

     virCloseCallback callback;
 };

@@ -279,6 +280,8 @@ virCloseCallbacksGetOne(void *payload,

     memcpy(data->list->entries[data->list->nentries - 1].uuid,
            uuid, VIR_UUID_BUFLEN);
+    memcpy(data->list->entries[data->list->nentries - 1].uuidstr,
+           uuidstr, VIR_UUID_STRING_BUFLEN);
     data->list->entries[data->list->nentries - 1].callback = closeDef->cb;
 }

@@ -332,7 +335,7 @@ virCloseCallbacksRun(virCloseCallbacksPtr closeCallbacks,

     for (i = 0; i < list->nentries; i++) {
         virHashRemoveEntry(closeCallbacks->list,
-                           list->entries[i].uuid);
+                           list->entries[i].uuidstr);

I think the CPU time wasted by doing virUUIDFormat here again is
negligible and easier than writing a Hash function that works on
VIR_UUID buffers :)

Jan

Yeah, sounds reasonable. I'll send through a v2 patch shortly. I've also got a few extra patches lined up, but I'll start a new series for those.

Thanks for the review!

- Michael

[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]