[PATCH] util: virExec may blocked by reading pipe if grandchild prematurely exit
Michal Prívozník
mprivozn at redhat.com
Wed Nov 24 11:01:29 UTC 2021
On 11/24/21 03:33, Yi Wang wrote:
> From: Xu Chao <xu.chao6 at zte.com.cn>
>
> When VIR_EXEC_DAEMON is set, if virPidFileAcquirePath/virSetInherit failed,
> then pipesync[0] can not be closed when granchild process exit, because
> pipesync[1] still opened in child process. and then saferead in child
> process may blocked forever, and left grandchild process in defunct state.
>
> Signed-off-by: Xu Chao <xu.chao6 at zte.com.cn>
> Signed-off-by: Yi Wang <wang.yi59 at zte.com.cn>
> ---
> src/util/vircommand.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/src/util/vircommand.c b/src/util/vircommand.c
> index fead373729..fa71f40d81 100644
> --- a/src/util/vircommand.c
> +++ b/src/util/vircommand.c
> @@ -782,6 +782,9 @@ virExec(virCommand *cmd)
> }
>
> if (pid > 0) {
> + /* close pipe[1], then the pipe can be closed if grandchild
> + * died prematurely */
> + VIR_FORCE_CLOSE(pipesync[1]);
> /* The parent expect us to have written the pid file before
> * exiting. Wait here for the child to write it and signal us. */
> if (cmd->pidfile &&
>
I've tweaked the comment a bit to describe who has the write end open.
Reviewed-by: Michal Privoznik <mprivozn at redhat.com>
and pushed. Congratulations on your first libvirt contribution!
Michal
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