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authorSteffen Maier <maier@linux.ibm.com>2018-11-08 15:44:45 +0100
committerMartin K. Petersen <martin.petersen@oracle.com>2018-11-15 15:01:17 -0500
commitf9eca022760079c0556cb311e3aa9091a3921a31 (patch)
tree95242c128b66bf465f03c7f6ebfe913b5b2c425b /drivers/s390/scsi/zfcp_dbf.c
parent2c53d8a0cce4f8490a1829867930b519e65db2b4 (diff)
scsi: zfcp: drop duplicate fsf_command from zfcp_fsf_req which is also in QTCB header
Status read buffers (SRBs, unsolicited notifications) never use a QTCB [zfcp_fsf_req_create()]. zfcp_fsf_req_send() already uses this to distinguish SRBs from other FSF request types. We can re-use this method in zfcp_fsf_req_complete(). Introduce a helper function to make the check for req->qtcb less magic. SRBs always are FSF_QTCB_UNSOLICITED_STATUS, so we can hard-code this for the two trace functions dealing with SRBs. All other FSF request types have a QTCB and we can get the fsf_command from there. zfcp_dbf_hba_fsf_response() and thus zfcp_dbf_hba_fsf_res() are only called for non-SRB requests so it's safe to dereference the QTCB [zfcp_fsf_req_complete() returns early on SRB, else calls zfcp_fsf_protstatus_eval() which calls zfcp_dbf_hba_fsf_response()]. In zfcp_scsi_forget_cmnd() we guard the QTCB dereference with a preceding NULL check and rely on boolean shortcut evaluation. As a side effect, this causes an alignment hole which we can close in a later patch after having cleaned up all fields of struct zfcp_fsf_req. Before: $ pahole -C zfcp_fsf_req drivers/s390/scsi/zfcp.ko ... u32 status; /* 136 4 */ u32 fsf_command; /* 140 4 */ struct fsf_qtcb * qtcb; /* 144 8 */ ... After: $ pahole -C zfcp_fsf_req drivers/s390/scsi/zfcp.ko ... u32 status; /* 136 4 */ /* XXX 4 bytes hole, try to pack */ struct fsf_qtcb * qtcb; /* 144 8 */ ... Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/s390/scsi/zfcp_dbf.c')
-rw-r--r--drivers/s390/scsi/zfcp_dbf.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/s390/scsi/zfcp_dbf.c b/drivers/s390/scsi/zfcp_dbf.c
index 3b368fcf13f4..d20977bb27a4 100644
--- a/drivers/s390/scsi/zfcp_dbf.c
+++ b/drivers/s390/scsi/zfcp_dbf.c
@@ -81,7 +81,7 @@ void zfcp_dbf_hba_fsf_res(char *tag, int level, struct zfcp_fsf_req *req)
rec->id = ZFCP_DBF_HBA_RES;
rec->fsf_req_id = req->req_id;
rec->fsf_req_status = req->status;
- rec->fsf_cmd = req->fsf_command;
+ rec->fsf_cmd = q_head->fsf_command;
rec->fsf_seq_no = req->seq_no;
rec->u.res.req_issued = req->issued;
rec->u.res.prot_status = q_pref->prot_status;
@@ -94,7 +94,7 @@ void zfcp_dbf_hba_fsf_res(char *tag, int level, struct zfcp_fsf_req *req)
memcpy(rec->u.res.fsf_status_qual, &q_head->fsf_status_qual,
FSF_STATUS_QUALIFIER_SIZE);
- if (req->fsf_command != FSF_QTCB_FCP_CMND) {
+ if (q_head->fsf_command != FSF_QTCB_FCP_CMND) {
rec->pl_len = q_head->log_length;
zfcp_dbf_pl_write(dbf, (char *)q_pref + q_head->log_start,
rec->pl_len, "fsf_res", req->req_id);
@@ -127,7 +127,7 @@ void zfcp_dbf_hba_fsf_uss(char *tag, struct zfcp_fsf_req *req)
rec->id = ZFCP_DBF_HBA_USS;
rec->fsf_req_id = req->req_id;
rec->fsf_req_status = req->status;
- rec->fsf_cmd = req->fsf_command;
+ rec->fsf_cmd = FSF_QTCB_UNSOLICITED_STATUS;
if (!srb)
goto log;
@@ -174,7 +174,7 @@ void zfcp_dbf_hba_bit_err(char *tag, struct zfcp_fsf_req *req)
rec->id = ZFCP_DBF_HBA_BIT;
rec->fsf_req_id = req->req_id;
rec->fsf_req_status = req->status;
- rec->fsf_cmd = req->fsf_command;
+ rec->fsf_cmd = FSF_QTCB_UNSOLICITED_STATUS;
memcpy(&rec->u.be, &sr_buf->payload.bit_error,
sizeof(struct fsf_bit_error_payload));