From: Michael Roth <mdroth@linux.vnet.ibm.com>
To: qemu-devel@nongnu.org
Cc: mprivozn@redhat.com, aliguori@us.ibm.com, eblake@redhat.com,
jcody@redhat.com, lcapitulino@redhat.com
Subject: [Qemu-devel] [PATCH 10/13] qemu-ga: guest-shutdown: become synchronous
Date: Tue, 15 May 2012 09:48:56 -0500 [thread overview]
Message-ID: <1337093339-10786-11-git-send-email-mdroth@linux.vnet.ibm.com> (raw)
In-Reply-To: <1337093339-10786-1-git-send-email-mdroth@linux.vnet.ibm.com>
From: Luiz Capitulino <lcapitulino@redhat.com>
Last commit dropped qemu-ga's SIGCHLD handler, used to automatically
reap terminated children processes. This introduced a bug to
qmp_guest_shutdown(): it will generate zombies.
This problem probably doesn't matter in the success case, as the VM
will shutdown anyway, but let's do the right thing and reap the
created process. This ultimately means that guest-shutdown is now a
synchronous command.
An interesting side effect is that guest-shutdown is now able to
report an error to the client if shutting down fails.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
qga/commands-posix.c | 21 ++++++++++++++++-----
1 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 76c8235..68da71f 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -36,8 +36,9 @@
void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err)
{
- int ret;
const char *shutdown_flag;
+ int ret, status;
+ pid_t rpid, pid;
slog("guest-shutdown called, mode: %s", mode);
if (!has_mode || strcmp(mode, "powerdown") == 0) {
@@ -52,8 +53,8 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err)
return;
}
- ret = fork();
- if (ret == 0) {
+ pid = fork();
+ if (pid == 0) {
/* child, start the shutdown */
setsid();
fclose(stdin);
@@ -66,9 +67,19 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err)
slog("guest-shutdown failed: %s", strerror(errno));
}
exit(!!ret);
- } else if (ret < 0) {
- error_set(err, QERR_UNDEFINED_ERROR);
+ } else if (pid < 0) {
+ goto exit_err;
}
+
+ do {
+ rpid = waitpid(pid, &status, 0);
+ } while (rpid == -1 && errno == EINTR);
+ if (rpid == pid && WIFEXITED(status) && !WEXITSTATUS(status)) {
+ return;
+ }
+
+exit_err:
+ error_set(err, QERR_UNDEFINED_ERROR);
}
typedef struct GuestFileHandle {
--
1.7.4.1
next prev parent reply other threads:[~2012-05-15 14:50 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-15 14:48 [Qemu-devel] [PULL] qemu-ga fixes for 1.1 Michael Roth
2012-05-15 14:48 ` [Qemu-devel] [PATCH 01/13] qapi: add support for command options Michael Roth
2012-05-15 14:48 ` [Qemu-devel] [PATCH 02/13] qemu-ga: don't warn on no command return Michael Roth
2012-05-15 14:48 ` [Qemu-devel] [PATCH 03/13] qemu-ga: guest-shutdown: don't emit a success response Michael Roth
2012-05-15 14:48 ` [Qemu-devel] [PATCH 04/13] qemu-ga: guest-suspend-disk: " Michael Roth
2012-05-15 14:48 ` [Qemu-devel] [PATCH 05/13] qemu-ga: guest-suspend-ram: " Michael Roth
2012-05-15 14:48 ` [Qemu-devel] [PATCH 06/13] qemu-ga: guest-suspend-hybrid: " Michael Roth
2012-05-15 14:48 ` [Qemu-devel] [PATCH 07/13] qemu-ga: make reopen_fd_to_null() public Michael Roth
2012-05-15 14:48 ` [Qemu-devel] [PATCH 08/13] qemu-ga: become_daemon(): reopen standard fds to /dev/null Michael Roth
2012-05-15 14:48 ` [Qemu-devel] [PATCH 09/13] qemu-ga: guest-suspend: make the API synchronous Michael Roth
2012-05-15 14:48 ` Michael Roth [this message]
2012-05-15 14:48 ` [Qemu-devel] [PATCH 11/13] qemu-ga: guest-shutdown: use only async-signal-safe functions Michael Roth
2012-05-15 14:48 ` [Qemu-devel] [PATCH 12/13] qemu-ga: fix segv after failure to open log file Michael Roth
2012-05-15 14:48 ` [Qemu-devel] [PATCH 13/13] qemu-ga: align versioning with QEMU_VERSION Michael Roth
2012-05-21 16:51 ` [Qemu-devel] [PULL] qemu-ga fixes for 1.1 Luiz Capitulino
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