On Sun, Apr 6, 2014, Michael Christie <micha...@cs.wisc.edu> wrote: > On Apr 6, 2014, Or Gerlitz <ogerl...@mellanox.com> wrote:
> > the kernel code path of iscsi_complete_pdu--> __iscsi_complete_pdu --> > > iscsi_scsi_cmd_rsp > > uses a "datalen" value which should account for the length of the data > > received from the target. > > > > In iser/iscsi_iser_recv() we don't skip the AHS in case the target sent it > > and I'd like to fix it. > > I wasn't fully surewhat is done today in iscsi_tcp... I see few hits in > > libiscsi_tcp.c for ahslen but didn't manageto spot the a place where the > > ahs is being skipped, is it? > > You saw iscsi_tcp_hdr_recv_done in libiscsi_tcp.c right? We just have a > preallocated header buffer that we copy to. That function just detects the > ahs then sets things up so iscsi_tcp_recv_skb reads it into that buffer. Yes, I saw iscsi_tcp_hdr_recv_done() but I wasn't sure to fully follow on what's exactly done there w.r.t to the AHS, it reads the ahs len and adds it to two size fields, and I was under the impression that the AHS is skipped before the data pointer is provided to the iscsi_complete_pdu--> __iscsi_complete_pdu --> iscsi_scsi_cmd_rsp call chain but couldn't prove it to myself, so the question, is this really the case? and I can align iser to do the same practice. > > Another related issue is with this code in iscsi_scsi_cmd_rsp(): > > > > invalid_datalen: > > iscsi_conn_printk(KERN_ERR, conn, > > "Got CHECK_CONDITION but invalid > > data " > > "buffer size of %d\n", datalen); > > sc->result = DID_BAD_TARGET << 16; > > goto out; > > } > > > > senselen = get_unaligned_be16(data); > > if (datalen < senselen) > > goto invalid_datalen; > > > > > > Partial sense can come into play e.g with target (e.g non-Linux one) > > sending sense > > which is bigger than SCSI_SENSE_BUFFERSIZE or b/c the initiator RDSL > > doesn't let them > > send the whole sense, etc. > > > > This code isn't willing to provide the SCSI midlayer with partial sense, > > why not do > > allow that? > > We have never seen a target do that, so you are the first person to request > support. Send a patch. If the iser initiator RDSL is small enough and the target correctly takes it into account it can happen. Also we saw it with non-Linux iser target that was attempting to send sense > Linux SCSI_SENSE_BUFFERSIZE, for the time being we told them to chop @ their side, but moving fwd, I think the correct behaviour is what described above, so yes, patch is needed here. -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at http://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
