libvirt/105dace2-revert-virProcessGetStatInfo.patch

commit 105dace22cc7b5b18d72a4dcad4a2cf386ce5c99
Author: Michal Prívozník <mprivozn@redhat.com>
Date:   Tue Jan 18 12:40:09 2022 +0100

    Revert "report error when virProcessGetStatInfo() is unable to parse data"
    
    This reverts commit 938382b60ae5bd1f83b5cb09e1ce68b9a88f679a.
    
    Turns out, the commit did more harm than good. It changed
    semantics on some public APIs. For instance, while
    qemuDomainGetInfo() previously did not returned an error it does
    now. While the calls to virProcessGetStatInfo() is guarded with
    virDomainObjIsActive() it doesn't necessarily mean that QEMU's
    PID is still alive. QEMU might be gone but we just haven't
    realized it (e.g. because the eof handler thread is waiting for a
    job).
    
    Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2041610
    Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
    Reviewed-by: Andrea Bolognani <abologna@redhat.com>

Index: libvirt-8.0.0/src/ch/ch_driver.c
===================================================================
--- libvirt-8.0.0.orig/src/ch/ch_driver.c
+++ libvirt-8.0.0/src/ch/ch_driver.c
@@ -1073,6 +1073,8 @@ chDomainHelperGetVcpus(virDomainObj *vm,
             if (virProcessGetStatInfo(&vcpuinfo->cpuTime,
                                       &vcpuinfo->cpu, NULL,
                                       vm->pid, vcpupid) < 0) {
+                virReportSystemError(errno, "%s",
+                                      _("cannot get vCPU placement & pCPU time"));
                 return -1;
             }
         }
Index: libvirt-8.0.0/src/qemu/qemu_driver.c
===================================================================
--- libvirt-8.0.0.orig/src/qemu/qemu_driver.c
+++ libvirt-8.0.0/src/qemu/qemu_driver.c
@@ -1359,6 +1359,8 @@ qemuDomainHelperGetVcpus(virDomainObj *v
             if (virProcessGetStatInfo(&vcpuinfo->cpuTime,
                                       &vcpuinfo->cpu, NULL,
                                       vm->pid, vcpupid) < 0) {
+                virReportSystemError(errno, "%s",
+                                     _("cannot get vCPU placement & pCPU time"));
                 return -1;
             }
         }
@@ -2519,6 +2521,8 @@ qemuDomainGetInfo(virDomainPtr dom,
     if (virDomainObjIsActive(vm)) {
         if (virProcessGetStatInfo(&(info->cpuTime), NULL, NULL,
                                   vm->pid, 0) < 0) {
+            virReportError(VIR_ERR_OPERATION_FAILED, "%s",
+                           _("cannot read cputime for domain"));
             goto cleanup;
         }
     }
@@ -10526,7 +10530,8 @@ qemuDomainMemoryStatsInternal(virQEMUDri
     }
 
     if (virProcessGetStatInfo(NULL, NULL, &rss, vm->pid, 0) < 0) {
-        virResetLastError();
+        virReportError(VIR_ERR_OPERATION_FAILED, "%s",
+                       _("cannot get RSS for domain"));
     } else {
         stats[ret].tag = VIR_DOMAIN_MEMORY_STAT_RSS;
         stats[ret].val = rss;
Index: libvirt-8.0.0/src/util/virprocess.c
===================================================================
--- libvirt-8.0.0.orig/src/util/virprocess.c
+++ libvirt-8.0.0/src/util/virprocess.c
@@ -1784,10 +1784,7 @@ virProcessGetStatInfo(unsigned long long
         virStrToLong_ullp(proc_stat[VIR_PROCESS_STAT_STIME], NULL, 10, &systime) < 0 ||
         virStrToLong_l(proc_stat[VIR_PROCESS_STAT_RSS], NULL, 10, &rss) < 0 ||
         virStrToLong_i(proc_stat[VIR_PROCESS_STAT_PROCESSOR], NULL, 10, &cpu) < 0) {
-        virReportError(VIR_ERR_INTERNAL_ERROR,
-                       _("cannot parse process status data for pid '%d/%d'"),
-                       (int) pid, (int) tid);
-        return -1;
+        VIR_WARN("cannot parse process status data");
     }
 
     /* We got jiffies
@@ -1884,8 +1881,7 @@ virProcessGetStatInfo(unsigned long long
                       pid_t pid G_GNUC_UNUSED,
                       pid_t tid G_GNUC_UNUSED)
 {
-    virReportSystemError(ENOSYS, "%s",
-                         _("Process statistics data is not supported on this platform"));
+    errno = ENOSYS;
     return -1;
 }