From 4765617d7b753482923a34fa81920d278c04dabc Mon Sep 17 00:00:00 2001 From: Steffen Maier Date: Wed, 10 Aug 2016 18:30:45 +0200 Subject: [PATCH] zfcp: fix ELS/GS request&response length for hardware data router commit 70369f8e15b220f50a16348c79a61d3f7054813c upstream. In the hardware data router case, introduced with kernel 3.2 commit 86a9668a8d29 ("[SCSI] zfcp: support for hardware data router") the ELS/GS request&response length needs to be initialized as in the chained SBAL case. Otherwise, the FCP channel rejects ELS requests with FSF_REQUEST_SIZE_TOO_LARGE. Such ELS requests can be issued by user space through BSG / HBA API, or zfcp itself uses ADISC ELS for remote port link test on RSCN. The latter can cause a short path outage due to unnecessary remote target port recovery because the always failing ADISC cannot detect extremely short path interruptions beyond the local FCP channel. Below example is decoded with zfcpdbf from s390-tools: Timestamp : ... Area : SAN Subarea : 00 Level : 1 Exception : - CPU id : .. Caller : zfcp_dbf_san_req+0408 Record id : 1 Tag : fssels1 Request id : 0x Destination ID : 0x00 Payload info : 52000000 00000000 [ADISC] 00 00000000 00000000 00000000 00000000 00000000 Timestamp : ... Area : HBA Subarea : 00 Level : 1 Exception : - CPU id : .. Caller : zfcp_dbf_hba_fsf_res+0740 Record id : 1 Tag : fs_ferr Request id : 0x Request status : 0x00000010 FSF cmnd : 0x0000000b [FSF_QTCB_SEND_ELS] FSF sequence no: 0x... FSF issued : ... FSF stat : 0x00000061 [FSF_REQUEST_SIZE_TOO_LARGE] FSF stat qual : 00000000 00000000 00000000 00000000 Prot stat : 0x00000100 Prot stat qual : 00000000 00000000 00000000 00000000 Signed-off-by: Steffen Maier Fixes: 86a9668a8d29 ("[SCSI] zfcp: support for hardware data router") Reviewed-by: Benjamin Block Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen Signed-off-by: Ben Hutchings --- drivers/s390/scsi/zfcp_fsf.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c index a41673fdd222..d0cbcfdce867 100644 --- a/drivers/s390/scsi/zfcp_fsf.c +++ b/drivers/s390/scsi/zfcp_fsf.c @@ -960,8 +960,12 @@ static int zfcp_fsf_setup_ct_els_sbals(struct zfcp_fsf_req *req, if (zfcp_adapter_multi_buffer_active(adapter)) { if (zfcp_qdio_sbals_from_sg(qdio, &req->qdio_req, sg_req)) return -EIO; + qtcb->bottom.support.req_buf_length = + zfcp_qdio_real_bytes(sg_req); if (zfcp_qdio_sbals_from_sg(qdio, &req->qdio_req, sg_resp)) return -EIO; + qtcb->bottom.support.resp_buf_length = + zfcp_qdio_real_bytes(sg_resp); zfcp_qdio_set_data_div(qdio, &req->qdio_req, zfcp_qdio_sbale_count(sg_req)); -- 2.39.2