c/r: write status only after trying to parse the pid

Previously, we write a "success" status but tried to parse the pid. This
meant that we wouldn't notice a successful restore but failure to parse the
pid, which was a little strange.

We still don't know the child pid, so we will end up with a restored
process tree and a running container, but at least in this case the API
will return false indicating that something failed.

We could kill(-1, 9) in this case, but since liblxc runs as root sometimes
(e.g. LXD), that would be a Very Bad Thing.

Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
This commit is contained in:
Tycho Andersen 2016-08-26 16:29:45 -04:00
parent 1f56665557
commit f3886023c1

View File

@ -723,15 +723,6 @@ static void do_restore(struct lxc_container *c, int status_pipe, struct migrate_
goto out_fini_handler;
}
ret = write(status_pipe, &status, sizeof(status));
close(status_pipe);
status_pipe = -1;
if (sizeof(status) != ret) {
SYSERROR("failed to write all of status");
goto out_fini_handler;
}
if (WIFEXITED(status)) {
char buf[4096];
@ -780,6 +771,15 @@ static void do_restore(struct lxc_container *c, int status_pipe, struct migrate_
close(pipes[0]);
ret = write(status_pipe, &status, sizeof(status));
close(status_pipe);
status_pipe = -1;
if (sizeof(status) != ret) {
SYSERROR("failed to write all of status");
goto out_fini_handler;
}
/*
* See comment in lxcapi_start; we don't care if these
* fail because it's just a beauty thing. We just
@ -805,7 +805,12 @@ out_fini_handler:
out:
if (status_pipe >= 0) {
status = 1;
/* ensure getting here was a failure, e.g. if we failed to
* parse the child pid or something, even after a successful
* restore
*/
if (!status)
status = 1;
if (write(status_pipe, &status, sizeof(status)) != sizeof(status)) {
SYSERROR("writing status failed");
}