> -----Original Message----- > From: James Bottomley [mailto:James.Bottomley@xxxxxxxxxxxxxxxxxxxxx] > Sent: Thursday, January 7, 2016 3:49 PM > To: KY Srinivasan <kys@xxxxxxxxxxxxx>; gregkh@xxxxxxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; ohering@xxxxxxxx; > jbottomley@xxxxxxxxxxxxx; hch@xxxxxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx; > apw@xxxxxxxxxxxxx; vkuznets@xxxxxxxxxx; jasowang@xxxxxxxxxx; > martin.petersen@xxxxxxxxxx; hare@xxxxxxx > Cc: stable@xxxxxxxxxxxxxxx > Subject: Re: [PATCH 1/1] scsi: scsi_transport_fc: Fix a bug in the error > handling function > > On Thu, 2016-01-07 at 16:40 -0800, K. Y. Srinivasan wrote: > > The macro startget_to_rport() can return NULL; handle that case > > properly. > > OK, can we unwind why you think you could possibly need this? It would > mean that fc_timed_out was called for a non-FC device, which was > thought to be an impossibility when the fc transport class was > designed. As you know, on Hyper-V, FC devices are handled exactly like normal scsi devices and the only additional information that is provided for FC devices is the WWN for port and node. Till recently, I was not publishing the WWN in the guest and so I was not even using the FC transport. Recently, I implemented support for publishing the WWN in the guest and for that I am using the FC transport for FC hosts. When an FC LUN is dynamically removed, sometimes I see the timeout occurring and since there is no rport associated with these devices I am hitting the issue this patch is addressing. I could have addressed this problem by establishing a storvsc specific time out function even for FC devices - the same timeout function that I currently use for scsi devices - storvsc_eh_timed_out(). I chose to instead fix the fc_timed_out() function since the code was not handling a possible condition. Regards, K. Y > > James > > > Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> > > Cc: <stable@xxxxxxxxxxxxxxx> > > --- > > drivers/scsi/scsi_transport_fc.c | 2 +- > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > diff --git a/drivers/scsi/scsi_transport_fc.c > > b/drivers/scsi/scsi_transport_fc.c > > index 24eaaf6..42a908f 100644 > > --- a/drivers/scsi/scsi_transport_fc.c > > +++ b/drivers/scsi/scsi_transport_fc.c > > @@ -2081,7 +2081,7 @@ fc_timed_out(struct scsi_cmnd *scmd) > > { > > struct fc_rport *rport = starget_to_rport(scsi_target(scmd > > ->device)); > > > > - if (rport->port_state == FC_PORTSTATE_BLOCKED) > > + if ((rport == NULL) || (rport->port_state == > > FC_PORTSTATE_BLOCKED)) > > return BLK_EH_RESET_TIMER; > > > > return BLK_EH_NOT_HANDLED; ��.n��������+%������w��{.n�����������ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f