scsi: zfcp: use common code fcp_cmnd and fcp_resp with union in fsf_qtcb_bottom_io

This eases crash dump analysis by automatically dissecting these
protocol headers at least somewhat rather than getting a string
interpretation of large unstructured character array buffer fields.

Also, we can get rid of some unnecessary and error-prone type casts.

This change is possible since v2.6.33 commit 4318e08c84e4
("[SCSI] zfcp: Update FCP protocol related code").

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/s390/scsi/zfcp_dbf.c b/drivers/s390/scsi/zfcp_dbf.c
index 34367d1729610eac0f4f7c00c76a49db680c6464..225e60d5d3fcd72a49b83d2bd514508ec617c2a6 100644 (file)
--- a/drivers/s390/scsi/zfcp_dbf.c
+++ b/drivers/s390/scsi/zfcp_dbf.c
@@ -573,8 +573,7 @@ void zfcp_dbf_scsi(char *tag, int level, struct scsi_cmnd *sc,
        if (fsf) {
                rec->fsf_req_id = fsf->req_id;
                rec->pl_len = FCP_RESP_WITH_EXT;
-               fcp_rsp = (struct fcp_resp_with_ext *)
-                               &(fsf->qtcb->bottom.io.fcp_rsp);
+               fcp_rsp = &(fsf->qtcb->bottom.io.fcp_rsp.iu);
                /* mandatory parts of FCP_RSP IU in this SCSI record */
                memcpy(&rec->fcp_rsp, fcp_rsp, FCP_RESP_WITH_EXT);
                if (fcp_rsp->resp.fr_flags & FCP_RSP_LEN_VAL) {

diff --git a/drivers/s390/scsi/zfcp_dbf.h b/drivers/s390/scsi/zfcp_dbf.h
index b60667c145fdfa47e48248efc11969ccbc6ce149..33ccf15b63e0cb0253098425ee7e446913e54cfe 100644 (file)
--- a/drivers/s390/scsi/zfcp_dbf.h
+++ b/drivers/s390/scsi/zfcp_dbf.h
@@ -301,7 +301,7 @@ bool zfcp_dbf_hba_fsf_resp_suppress(struct zfcp_fsf_req *req)
 
        if (qtcb->prefix.qtcb_type != FSF_IO_COMMAND)
                return false; /* not an FCP response */
-       fcp_rsp = (struct fcp_resp *)&qtcb->bottom.io.fcp_rsp;
+       fcp_rsp = &qtcb->bottom.io.fcp_rsp.iu.resp;
        rsp_flags = fcp_rsp->fr_flags;
        fr_status = fcp_rsp->fr_status;
        return (fsf_stat == FSF_FCP_RSP_AVAILABLE) &&

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 9f73b8fc7f3bdf79b56d67b9b4da39de7b2c1227..6ddaee5f3701a1cafdd54f782426defbe3964554 100644 (file)
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -2143,7 +2143,8 @@ static void zfcp_fsf_fcp_cmnd_handler(struct zfcp_fsf_req *req)
                zfcp_scsi_dif_sense_error(scpnt, 0x3);
                goto skip_fsfstatus;
        }
-       fcp_rsp = (struct fcp_resp_with_ext *) &req->qtcb->bottom.io.fcp_rsp;
+       BUILD_BUG_ON(sizeof(struct fcp_resp_with_ext) > FSF_FCP_RSP_SIZE);
+       fcp_rsp = &req->qtcb->bottom.io.fcp_rsp.iu;
        zfcp_fc_eval_fcp_rsp(fcp_rsp, scpnt);
 
 skip_fsfstatus:
@@ -2256,7 +2257,8 @@ int zfcp_fsf_fcp_cmnd(struct scsi_cmnd *scsi_cmnd)
        if (zfcp_fsf_set_data_dir(scsi_cmnd, &io->data_direction))
                goto failed_scsi_cmnd;
 
-       fcp_cmnd = (struct fcp_cmnd *) &req->qtcb->bottom.io.fcp_cmnd;
+       BUILD_BUG_ON(sizeof(struct fcp_cmnd) > FSF_FCP_CMND_SIZE);
+       fcp_cmnd = &req->qtcb->bottom.io.fcp_cmnd.iu;
        zfcp_fc_scsi_to_fcp(fcp_cmnd, scsi_cmnd, 0);
 
        if ((scsi_get_prot_op(scsi_cmnd) != SCSI_PROT_NORMAL) &&
@@ -2301,7 +2303,7 @@ static void zfcp_fsf_fcp_task_mgmt_handler(struct zfcp_fsf_req *req)
 
        zfcp_fsf_fcp_handler_common(req);
 
-       fcp_rsp = (struct fcp_resp_with_ext *) &req->qtcb->bottom.io.fcp_rsp;
+       fcp_rsp = &req->qtcb->bottom.io.fcp_rsp.iu;
        rsp_info = (struct fcp_resp_rsp_info *) &fcp_rsp[1];
 
        if ((rsp_info->rsp_code != FCP_TMF_CMPL) ||
@@ -2350,7 +2352,7 @@ struct zfcp_fsf_req *zfcp_fsf_fcp_task_mgmt(struct scsi_cmnd *scmnd,
 
        zfcp_qdio_set_sbale_last(qdio, &req->qdio_req);
 
-       fcp_cmnd = (struct fcp_cmnd *) &req->qtcb->bottom.io.fcp_cmnd;
+       fcp_cmnd = &req->qtcb->bottom.io.fcp_cmnd.iu;
        zfcp_fc_scsi_to_fcp(fcp_cmnd, scmnd, tm_flags);
 
        zfcp_fsf_start_timer(req, ZFCP_SCSI_ER_TIMEOUT);

diff --git a/drivers/s390/scsi/zfcp_fsf.h b/drivers/s390/scsi/zfcp_fsf.h
index ea3c76ac0de14dc8ea9ad147d1f5b9ab80cc1172..88feba5bfda433bf7dba59ef3ed2d09af73f596c 100644 (file)
--- a/drivers/s390/scsi/zfcp_fsf.h
+++ b/drivers/s390/scsi/zfcp_fsf.h
@@ -3,7 +3,7 @@
  *
  * Interface to the FSF support functions.
  *
- * Copyright IBM Corp. 2002, 2016
+ * Copyright IBM Corp. 2002, 2017
  */
 
 #ifndef FSF_H
@@ -312,8 +312,14 @@ struct fsf_qtcb_bottom_io {
        u32 data_block_length;
        u32 prot_data_length;
        u8  res2[4];
-       u8  fcp_cmnd[FSF_FCP_CMND_SIZE];
-       u8  fcp_rsp[FSF_FCP_RSP_SIZE];
+       union {
+               u8              byte[FSF_FCP_CMND_SIZE];
+               struct fcp_cmnd iu;
+       }   fcp_cmnd;
+       union {
+               u8                       byte[FSF_FCP_RSP_SIZE];
+               struct fcp_resp_with_ext iu;
+       }   fcp_rsp;
        u8  res3[64];
 } __attribute__ ((packed));