Re: [dpdk-dev] [PATCH 1/3] vhost: do not generate signal when sendmsg fails

[Tiwei Bie <tiwei.bie@intel.com>]

On Thu, Mar 29, 2018 at 03:41:23PM +0200, Maxime Coquelin wrote:
> On 03/29/2018 03:25 PM, Tiwei Bie wrote:
> > On Thu, Mar 29, 2018 at 02:19:35PM +0200, Maxime Coquelin wrote:
> > > Hi Tiwei,
> > > 
> > > On 03/06/2018 11:43 AM, Tiwei Bie wrote:
> > > > Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> > > 
> > > Could you please elaborate a bit more why this is needed?
> > > Is it fixing a real issue or just an improvement?
> > 
> > My bad, I really should write a more useful commit log..
> > 
> > I saw your comments on this mail:
> > 
> > http://dpdk.org/ml/archives/dev/2018-March/094201.html
> > 
> > Thank you so much! :-)
> > 
> > It's fixing an issue I met when adding the vDPA support.
> > SIGPIPE would be generated when sending messages via a
> > closed slave fd, and it will terminate the process by
> > default. But as a library, we shouldn't crash the process
> > in this case, instead we just need to return with an error.
> > I didn't meet this issue without my vDPA related changes,
> > so I didn't put a fixline on it. That is to say, I'm
> > treating it as an improvement.
> 
> Great, thanks for the details!
> I'll apply the patch with below commit message.

Thank you very much! :-)

Best regards,
Tiwei Bie

> 
> Maxime
> > 
> > Below is the commit log for your reference:
> > 
> > ------ START HERE ------
> > 
> > vhost: do not generate signal when sendmsg fails
> > 
> > More precisely, do not generate a SIGPIPE signal if the peer
> > has closed the connection. Otherwise, it will terminate the
> > process by default. As a library, we should avoid terminating
> > the application process when error happens and just need to
> > return with an error.
> > 
> > ------ END HERE ------
> > 
> > Thanks again! :-)
> > 
> > Best regards,
> > Tiwei Bie
> > 
> > > 
> > > Thanks!
> > > Maxime
> > > > ---
> > > >    lib/librte_vhost/socket.c | 2 +-
> > > >    1 file changed, 1 insertion(+), 1 deletion(-)
> > > > 
> > > > diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
> > > > index 0354740fa..d703d2114 100644
> > > > --- a/lib/librte_vhost/socket.c
> > > > +++ b/lib/librte_vhost/socket.c
> > > > @@ -181,7 +181,7 @@ send_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num)
> > > >    	}
> > > >    	do {
> > > > -		ret = sendmsg(sockfd, &msgh, 0);
> > > > +		ret = sendmsg(sockfd, &msgh, MSG_NOSIGNAL);
> > > >    	} while (ret < 0 && errno == EINTR);
> > > >    	if (ret < 0) {
> > > >