[dpdk-stable] [PATCH v2] example/ipv4_multicast: fix app hanging when using clone

[Lipiec, Herakliusz]

Hi Dong,
I think that if a developer is to manipulate ol_flags, then its onto that developer to take care of copying ol_flags .
Regards Herakliusz

> -----Original Message-----
> From: Wang, Dong1
> Sent: Wednesday, November 14, 2018 10:09 AM
> To: Ananyev, Konstantin <konstantin.ananyev at intel.com>; Lipiec, Herakliusz
> <herakliusz.lipiec at intel.com>; dev at dpdk.org
> Cc: thomas at monjalon.net; Burakov, Anatoly <anatoly.burakov at intel.com>;
> stable at dpdk.org
> Subject: RE: [PATCH v2] example/ipv4_multicast: fix app hanging when using
> clone
> 
> Hi Konstantin,
> 
> In this example, no flags be set by user, so no need to copy flags from original
> mbuf.
> I'm thinking about some DPDK developers may create their own application
> based on this example,  they add some flags before packet be cloned.
> 
> Regards,
> Dong
> 
> -----Original Message-----
> From: Ananyev, Konstantin
> Sent: Wednesday, November 14, 2018 17:03
> To: Wang, Dong1 <dong1.wang at intel.com>; Lipiec, Herakliusz
> <herakliusz.lipiec at intel.com>; dev at dpdk.org
> Cc: thomas at monjalon.net; Burakov, Anatoly <anatoly.burakov at intel.com>;
> stable at dpdk.org
> Subject: RE: [PATCH v2] example/ipv4_multicast: fix app hanging when using
> clone
> 
> Hi Dong,
> 
> > Hi Herakliusz,
> >
> > Since pkt->ol_flags might set some other bits except
> > IND_ATTACHED_MBUF, how about set its value to original pkt->ol_flag
> 
> It could be done, but not sure what is the point?
> Which flags you think we need to copy from cloned mbuf (segment #2) to
> new header?
> Konstantin
> 
> >
> > Regards,
> > Dong
> >
> > -----Original Message-----
> > From: Lipiec, Herakliusz
> > Sent: Tuesday, November 13, 2018 19:49
> > To: dev at dpdk.org
> > Cc: Ananyev, Konstantin <konstantin.ananyev at intel.com>; Wang, Dong1
> > <dong1.wang at intel.com>; thomas at monjalon.net; Burakov, Anatoly
> > <anatoly.burakov at intel.com>; Lipiec, Herakliusz
> > <herakliusz.lipiec at intel.com>; stable at dpdk.org
> > Subject: [PATCH v2] example/ipv4_multicast: fix app hanging when using
> > clone
> >
> > The ipv4_multicast sample application was dropping packets when using
> > mbuf clone. When creating an L2 header and copying metadata from the
> > source packet, the ol_flags were also copied along with all the other
> metadata. Because the cloned packet had IND_ATTACHED_MBUF flag set in
> its ol_flags, this caused the packets to never be freed when using
> rte_pktmbuf_free.
> > Since copying ol_flags from the cloned packet is not necessary in the first
> place, just don't do it.
> >
> > Fixes: af75078fece3 ("first public release")
> > CC: stable at dpdk.org
> >
> > Reported-by: Wang Dong <dong1.wang at intel.com>
> > Signed-off-by: Herakliusz Lipiec <herakliusz.lipiec at intel.com>
> > ---
> >  doc/guides/sample_app_ug/ipv4_multicast.rst | 1 -
> >  examples/ipv4_multicast/main.c              | 2 --
> >  2 files changed, 3 deletions(-)
> >
> > diff --git a/doc/guides/sample_app_ug/ipv4_multicast.rst
> > b/doc/guides/sample_app_ug/ipv4_multicast.rst
> > index ce1474ec7..f6efa7f6f 100644
> > --- a/doc/guides/sample_app_ug/ipv4_multicast.rst
> > +++ b/doc/guides/sample_app_ug/ipv4_multicast.rst
> > @@ -319,7 +319,6 @@ It is the mcast_out_pkt() function that performs the
> packet duplication (either
> >          hdr->pkt.in_port = pkt->pkt.in_port;
> >          hdr->pkt.vlan_macip = pkt->pkt.vlan_macip;
> >          hdr->pkt.hash = pkt->pkt.hash;
> > -        hdr->ol_flags = pkt->ol_flags;
> >          rte_mbuf_sanity_check(hdr, RTE_MBUF_PKT, 1);
> >
> >          return hdr;
> > diff --git a/examples/ipv4_multicast/main.c
> > b/examples/ipv4_multicast/main.c index 4073a4907..428ca4694 100644
> > --- a/examples/ipv4_multicast/main.c
> > +++ b/examples/ipv4_multicast/main.c
> > @@ -266,8 +266,6 @@ mcast_out_pkt(struct rte_mbuf *pkt, int
> use_clone)
> >  	hdr->tx_offload = pkt->tx_offload;
> >  	hdr->hash = pkt->hash;
> >
> > -	hdr->ol_flags = pkt->ol_flags;
> > -
> >  	__rte_mbuf_sanity_check(hdr, 1);
> >  	return hdr;
> >  }
> > --
> > 2.17.1