On Tue, 25 Mar 2014 17:04:59 -0500 Serge Hallyn <serge.hal...@ubuntu.com> wrote:
> Quoting Stéphane Graber (stgra...@ubuntu.com): > > On Tue, Mar 25, 2014 at 05:58:32PM -0400, Dwight Engen wrote: > > > On Tue, 25 Mar 2014 15:50:06 -0500 > > > Serge Hallyn <serge.hal...@ubuntu.com> wrote: > > > > > > > If we start a lxc_wait on a container while it is exiting, it is > > > > possible that we open the command socket, then the monitor > > > > closes all its mainloop sockets and exit, then we send our > > > > credentials. Then we get killed by SIGPIPE. > > > > > > Hey Serge, this is an interesting condition. I'm a bit confused > > > where the race is, looking at lxc_wait it looks like we get the > > > monitor open before opening the command socket with lxc_getstate, > > > and the monitor shouldn't exit while we are still a client of it. > > > > It's a race which has been causing dozens of testrun failures on > > the CI infrastructure, so it's reasonably easy to hit :) > > > > And I think Serge meant s/monitor/command/ in there, the SIGPIPE we > > were getting was from the command socket when the container was > > about to die and exit. > > Yeah, unfortunately I call the task which waits on the container init > the 'container monitor'. Suppose I need a better name for it... But > that's what it does :) Yep, got it. I thought you meant monitord. Makes sense on the command socket, thanks. > > > > Handle that case, recognizing that if we get sigpipe then the > > > > container is (now) stopped. > > > > > > This makes sense in general, so I agree with the change. > > > > > > > Signed-off-by: Serge Hallyn <serge.hal...@ubuntu.com> > > > > --- > > > > src/lxc/af_unix.c | 4 ++-- > > > > src/lxc/commands.c | 11 ++++++++++- > > > > 2 files changed, 12 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/src/lxc/af_unix.c b/src/lxc/af_unix.c > > > > index a2de73e..46d8e50 100644 > > > > --- a/src/lxc/af_unix.c > > > > +++ b/src/lxc/af_unix.c > > > > @@ -158,7 +158,7 @@ int lxc_abstract_unix_send_fd(int fd, int > > > > sendfd, void *data, size_t size) msg.msg_iov = &iov; > > > > msg.msg_iovlen = 1; > > > > > > > > - return sendmsg(fd, &msg, 0); > > > > + return sendmsg(fd, &msg, MSG_NOSIGNAL); > > > > } > > > > > > > > int lxc_abstract_unix_recv_fd(int fd, int *recvfd, void *data, > > > > size_t size) @@ -230,7 +230,7 @@ int > > > > lxc_abstract_unix_send_credential(int fd, void *data, size_t > > > > size) msg.msg_iov = &iov; msg.msg_iovlen = 1; > > > > > > > > - return sendmsg(fd, &msg, 0); > > > > + return sendmsg(fd, &msg, MSG_NOSIGNAL); > > > > } > > > > > > > > int lxc_abstract_unix_rcv_credential(int fd, void *data, > > > > size_t size) diff --git a/src/lxc/commands.c > > > > b/src/lxc/commands.c index 6b46c2c..b71274c 100644 > > > > --- a/src/lxc/commands.c > > > > +++ b/src/lxc/commands.c > > > > @@ -263,6 +263,8 @@ static int lxc_cmd(const char *name, struct > > > > lxc_cmd_rr *cmd, int *stopped, > > > > ret = lxc_abstract_unix_send_credential(sock, > > > > &cmd->req, sizeof(cmd->req)); if (ret != sizeof(cmd->req)) { > > > > + if (errno == EPIPE) > > > > + goto epipe; > > > > SYSERROR("command %s failed to send req to > > > > '@%s' %d", lxc_cmd_str(cmd->req.cmd), offset, ret); > > > > if (ret >=0) > > > > @@ -271,8 +273,10 @@ static int lxc_cmd(const char *name, struct > > > > lxc_cmd_rr *cmd, int *stopped, } > > > > > > > > if (cmd->req.datalen > 0) { > > > > - ret = send(sock, cmd->req.data, > > > > cmd->req.datalen, 0); > > > > + ret = send(sock, cmd->req.data, > > > > cmd->req.datalen, MSG_NOSIGNAL); if (ret != cmd->req.datalen) { > > > > + if (errno == EPIPE) > > > > + goto epipe; > > > > SYSERROR("command %s failed to send > > > > request data to '@%s' %d", lxc_cmd_str(cmd->req.cmd), offset, > > > > ret); if (ret >=0) > > > > @@ -289,6 +293,11 @@ out: > > > > cmd->rsp.ret = sock; > > > > > > > > return ret; > > > > + > > > > +epipe: > > > > + close(sock); > > > > + *stopped = 1; > > > > + return 0; > > > > } > > > > > > > > int lxc_try_cmd(const char *name, const char *lxcpath) > > > > > > _______________________________________________ > > > lxc-devel mailing list > > > lxc-devel@lists.linuxcontainers.org > > > http://lists.linuxcontainers.org/listinfo/lxc-devel > > > > -- > > Stéphane Graber > > Ubuntu developer > > http://www.ubuntu.com > > > > > _______________________________________________ > > lxc-devel mailing list > > lxc-devel@lists.linuxcontainers.org > > http://lists.linuxcontainers.org/listinfo/lxc-devel > > _______________________________________________ > lxc-devel mailing list > lxc-devel@lists.linuxcontainers.org > http://lists.linuxcontainers.org/listinfo/lxc-devel _______________________________________________ lxc-devel mailing list lxc-devel@lists.linuxcontainers.org http://lists.linuxcontainers.org/listinfo/lxc-devel