[PATCH] Revert "report error when virProcessGetStatInfo() is unable to parse data"

[Ani Sinha]

On Tue, Jan 18, 2022 at 5:15 PM Michal Privoznik <mprivozn at redhat.com>
wrote:

> 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).


Doh!


>
> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2041610
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---
>  src/ch/ch_driver.c     | 2 ++
>  src/qemu/qemu_driver.c | 7 ++++++-
>  src/util/virprocess.c  | 8 ++------
>  3 files changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/src/ch/ch_driver.c b/src/ch/ch_driver.c
> index 3cbc668489..53e0872207 100644
> --- a/src/ch/ch_driver.c
> +++ b/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;
>              }
>          }
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index e150b86cef..373cd62536 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -1357,6 +1357,8 @@ qemuDomainHelperGetVcpus(virDomainObj *vm,
>              if (virProcessGetStatInfo(&vcpuinfo->cpuTime,
>                                        &vcpuinfo->cpu, NULL,
>                                        vm->pid, vcpupid) < 0) {
> +                virReportSystemError(errno, "%s",
> +                                     _("cannot get vCPU placement & pCPU
> time"));
>                  return -1;
>              }
>          }
> @@ -2517,6 +2519,8 @@ 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;
>          }
>      }
> @@ -10524,7 +10528,8 @@ qemuDomainMemoryStatsInternal(virQEMUDriver
> *driver,
>      }
>
>      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;
> diff --git a/src/util/virprocess.c b/src/util/virprocess.c
> index 85d8c8e747..b559a4257e 100644
> --- a/src/util/virprocess.c
> +++ b/src/util/virprocess.c
> @@ -1784,10 +1784,7 @@ virProcessGetStatInfo(unsigned long long *cpuTime,
>          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 *cpuTime
> G_GNUC_UNUSED,
>                        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;
>  }
>
> --
> 2.34.1
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20220118/7bcd6db3/attachment-0001.htm>