[libvirt] [PATCH] qemu_capabilities: fix issue with discarding old capabilities

[Pavel Hrdina]

There was a bug that if libvirtd binary has been updated than the
capability file wasn't reloaded therefore new capabilities introduced
in libvirt cannot be used because the cached version was loaded.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1135431

Signed-off-by: Pavel Hrdina <phrdina at redhat.com>
---
 src/qemu/qemu_capabilities.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 81ada48..dae89aa 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -286,6 +286,7 @@ struct _virQEMUCaps {
 
     char *binary;
     time_t ctime;
+    time_t selfctime;
 
     virBitmapPtr flags;
 
@@ -2689,7 +2690,7 @@ virQEMUCapsSaveCache(virQEMUCapsPtr qemuCaps, const char *filename)
     virBufferAsprintf(&buf, "<qemuctime>%llu</qemuctime>\n",
                       (long long)qemuCaps->ctime);
     virBufferAsprintf(&buf, "<selfctime>%llu</selfctime>\n",
-                      (long long)virGetSelfLastChanged());
+                      (long long)qemuCaps->selfctime);
 
     if (qemuCaps->usedQMP)
         virBufferAddLit(&buf, "<usedQMP/>\n");
@@ -2743,7 +2744,7 @@ virQEMUCapsSaveCache(virQEMUCapsPtr qemuCaps, const char *filename)
     VIR_DEBUG("Saved caps '%s' for '%s' with (%lld, %lld)",
               filename, qemuCaps->binary,
               (long long)qemuCaps->ctime,
-              (long long)virGetSelfLastChanged());
+              (long long)qemuCaps->selfctime);
 
     ret = 0;
  cleanup:
@@ -2871,12 +2872,12 @@ virQEMUCapsInitCached(virQEMUCapsPtr qemuCaps, const char *cacheDir)
 
     /* Discard if cache is older that QEMU binary */
     if (qemuctime != qemuCaps->ctime ||
-        selfctime < virGetSelfLastChanged()) {
+        selfctime < qemuCaps->selfctime) {
         VIR_DEBUG("Outdated cached capabilities '%s' for '%s' "
                   "(%lld vs %lld, %lld vs %lld)",
                   capsfile, qemuCaps->binary,
                   (long long)qemuctime, (long long)qemuCaps->ctime,
-                  (long long)selfctime, (long long)virGetSelfLastChanged());
+                  (long long)selfctime, (long long)qemuCaps->selfctime);
         ignore_value(unlink(capsfile));
         virQEMUCapsReset(qemuCaps);
         ret = 0;
@@ -3371,6 +3372,7 @@ virQEMUCapsPtr virQEMUCapsNewForBinary(const char *binary,
         goto error;
     }
     qemuCaps->ctime = sb.st_ctime;
+    qemuCaps->selfctime = virGetSelfLastChanged();
 
     /* Make sure the binary we are about to try exec'ing exists.
      * Technically we could catch the exec() failure, but that's
@@ -3420,7 +3422,8 @@ bool virQEMUCapsIsValid(virQEMUCapsPtr qemuCaps)
     if (stat(qemuCaps->binary, &sb) < 0)
         return false;
 
-    return sb.st_ctime == qemuCaps->ctime;
+    return sb.st_ctime == qemuCaps->ctime &&
+        virGetSelfLastChanged() >= qemuCaps->selfctime;
 }
 
 
-- 
1.8.5.5