From 6cacbd1b9233e98576c01f5245c7d95b2501f15d Mon Sep 17 00:00:00 2001
Message-Id: <6cacbd1b9233e98576c01f5245c7d95b2501f15d@dist-git>
From: =?UTF-8?q?J=C3=A1n=20Tomko?= <jtomko@redhat.com>
Date: Mon, 19 Jan 2015 10:48:30 +0100
Subject: [PATCH] Fix vmdef usage while in monitor in BlockStat* APIs
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https://bugzilla.redhat.com/show_bug.cgi?id=1161024

Make a local copy of the disk alias instead of pointing
to the domain definition, which might get freed if
the domain dies while we're in monitor.

Also exit early if that happens.

(cherry picked from commit 3f2139843760e6d5596b75db9df6af8c6e9c1ee6)
Signed-off-by: Ján Tomko <jtomko@redhat.com>

Conflicts:
  src/qemu/qemu_driver.c - missing qemuDomainEndAPI and maxOptions
    for block IO throttle
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/qemu/qemu_driver.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 97d850b..9eb5f9c 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -10120,6 +10120,7 @@ qemuDomainBlockStats(virDomainPtr dom,
     virDomainObjPtr vm;
     virDomainDiskDefPtr disk = NULL;
     qemuDomainObjPrivatePtr priv;
+    char *diskAlias = NULL;
 
     if (!*path) {
         virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
@@ -10155,11 +10156,14 @@ qemuDomainBlockStats(virDomainPtr dom,
         goto endjob;
     }
 
+    if (VIR_STRDUP(diskAlias, disk->info.alias) < 0)
+        goto endjob;
+
     priv = vm->privateData;
 
     qemuDomainObjEnterMonitor(driver, vm);
     ret = qemuMonitorGetBlockStatsInfo(priv->mon,
-                                       disk->info.alias,
+                                       diskAlias,
                                        &stats->rd_req,
                                        &stats->rd_bytes,
                                        NULL,
@@ -10169,7 +10173,8 @@ qemuDomainBlockStats(virDomainPtr dom,
                                        NULL,
                                        NULL,
                                        &stats->errs);
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        ret = -1;
 
  endjob:
     if (!qemuDomainObjEndJob(driver, vm))
@@ -10178,6 +10183,7 @@ qemuDomainBlockStats(virDomainPtr dom,
  cleanup:
     if (vm)
         virObjectUnlock(vm);
+    VIR_FREE(diskAlias);
     return ret;
 }
 
@@ -10193,11 +10199,11 @@ qemuDomainBlockStatsFlags(virDomainPtr dom,
     int idx;
     int tmp, ret = -1;
     virDomainObjPtr vm;
-    virDomainDiskDefPtr disk = NULL;
     qemuDomainObjPrivatePtr priv;
     long long rd_req, rd_bytes, wr_req, wr_bytes, rd_total_times;
     long long wr_total_times, flush_req, flush_total_times, errs;
     virTypedParameterPtr param;
+    char *diskAlias = NULL;
 
     virCheckFlags(VIR_TYPED_PARAM_STRING_OKAY, -1);
 
@@ -10226,6 +10232,7 @@ qemuDomainBlockStatsFlags(virDomainPtr dom,
     }
 
     if (*nparams != 0) {
+        virDomainDiskDefPtr disk = NULL;
         if ((idx = virDomainDiskIndexByName(vm->def, path, false)) < 0) {
             virReportError(VIR_ERR_INVALID_ARG,
                            _("invalid path: %s"), path);
@@ -10239,6 +10246,8 @@ qemuDomainBlockStatsFlags(virDomainPtr dom,
                             disk->dst);
              goto endjob;
         }
+        if (VIR_STRDUP(diskAlias, disk->info.alias) < 0)
+            goto endjob;
     }
 
     priv = vm->privateData;
@@ -10249,12 +10258,12 @@ qemuDomainBlockStatsFlags(virDomainPtr dom,
     ret = qemuMonitorGetBlockStatsParamsNumber(priv->mon, nparams);
 
     if (tmp == 0 || ret < 0) {
-        qemuDomainObjExitMonitor(driver, vm);
+        ignore_value(qemuDomainObjExitMonitor(driver, vm));
         goto endjob;
     }
 
     ret = qemuMonitorGetBlockStatsInfo(priv->mon,
-                                       disk->info.alias,
+                                       diskAlias,
                                        &rd_req,
                                        &rd_bytes,
                                        &rd_total_times,
@@ -10265,7 +10274,8 @@ qemuDomainBlockStatsFlags(virDomainPtr dom,
                                        &flush_total_times,
                                        &errs);
 
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        ret = -1;
 
     if (ret < 0)
         goto endjob;
@@ -10353,6 +10363,7 @@ qemuDomainBlockStatsFlags(virDomainPtr dom,
  cleanup:
     if (vm)
         virObjectUnlock(vm);
+    VIR_FREE(diskAlias);
     return ret;
 }
 
@@ -16544,7 +16555,8 @@ qemuDomainSetBlockIoTune(virDomainPtr dom,
         }
         qemuDomainObjEnterMonitor(driver, vm);
         ret = qemuMonitorSetBlockIoThrottle(priv->mon, device, &info);
-        qemuDomainObjExitMonitor(driver, vm);
+        if (qemuDomainObjExitMonitor(driver, vm) < 0)
+            ret = -1;
         if (ret < 0)
             goto endjob;
         vm->def->disks[idx]->blkdeviotune = info;
-- 
2.2.1