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scsi: zfcp: fix missing SCSI trace for result of eh_host_reset_handler

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For problem determination we need to see whether and why we were successful
or not. This allows deduction of scsi_eh escalation.

Example trace record formatted with zfcpdbf from s390-tools:

Timestamp      : ...
Area           : SCSI
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1
Tag            : schrh_r        SCSI host reset handler result
Request ID     : 0x0000000000000000                     none (invalid)
SCSI ID        : 0xffffffff                             none (invalid)
SCSI LUN       : 0xffffffff                             none (invalid)
SCSI LUN high  : 0xffffffff                             none (invalid)
SCSI result    : 0x00002002     field re-used for midlayer value: SUCCESS
                                or in other cases: 0x2009 == FAST_IO_FAIL
SCSI retries   : 0xff                                   none (invalid)
SCSI allowed   : 0xff                                   none (invalid)
SCSI scribble  : 0xffffffffffffffff                     none (invalid)
SCSI opcode    : ffffffff ffffffff ffffffff ffffffff    none (invalid)
FCP rsp inf cod: 0xff                                   none (invalid)
FCP rsp IU     : 00000000 00000000 00000000 00000000    none (invalid)
                 00000000 00000000

v2.6.35 commit a1dbfddd02 ("[SCSI] zfcp: Pass return code from
fc_block_scsi_eh to scsi eh") introduced the first return with something
other than the previously hardcoded single SUCCESS return path.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: a1dbfddd02 ("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh")
Cc: <stable@vger.kernel.org> #2.6.38+
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Steffen Maier 2018-05-17 19:14:43 +02:00 committed by Martin K. Petersen
parent cd43c221bb
commit df30781699
3 changed files with 48 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
drivers/s390/scsi/zfcp_dbf.c
View File

@ -643,6 +643,46 @@ void zfcp_dbf_scsi(char *tag, int level, struct scsi_cmnd *sc,
spin_unlock_irqrestore(&dbf->scsi_lock, flags);
}
/**
* zfcp_dbf_scsi_eh() - Trace event for special cases of scsi_eh callbacks.
* @tag: Identifier for event.
* @adapter: Pointer to zfcp adapter as context for this event.
* @scsi_id: SCSI ID/target to indicate scope of task management function (TMF).
* @ret: Return value of calling function.
*
* This SCSI trace variant does not depend on any of:
* scsi_cmnd, zfcp_fsf_req, scsi_device.
*/
void zfcp_dbf_scsi_eh(char *tag, struct zfcp_adapter *adapter,
unsigned int scsi_id, int ret)
{
struct zfcp_dbf *dbf = adapter->dbf;
struct zfcp_dbf_scsi *rec = &dbf->scsi_buf;
unsigned long flags;
static int const level = 1;
if (unlikely(!debug_level_enabled(adapter->dbf->scsi, level)))
return;
spin_lock_irqsave(&dbf->scsi_lock, flags);
memset(rec, 0, sizeof(*rec));
memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
rec->id = ZFCP_DBF_SCSI_CMND;
rec->scsi_result = ret; /* re-use field, int is 4 bytes and fits */
rec->scsi_retries = ~0;
rec->scsi_allowed = ~0;
rec->fcp_rsp_info = ~0;
rec->scsi_id = scsi_id;
rec->scsi_lun = (u32)ZFCP_DBF_INVALID_LUN;
rec->scsi_lun_64_hi = (u32)(ZFCP_DBF_INVALID_LUN >> 32);
rec->host_scribble = ~0;
memset(rec->scsi_opcode, 0xff, ZFCP_DBF_SCSI_OPCODE);
debug_event(dbf->scsi, level, rec, sizeof(*rec));
spin_unlock_irqrestore(&dbf->scsi_lock, flags);
}
static debug_info_t *zfcp_dbf_reg(const char *name, int size, int rec_size)
{
struct debug_info *d;

2
drivers/s390/scsi/zfcp_ext.h
View File

@ -49,6 +49,8 @@ extern void zfcp_dbf_san_res(char *, struct zfcp_fsf_req *);
extern void zfcp_dbf_san_in_els(char *, struct zfcp_fsf_req *);
extern void zfcp_dbf_scsi(char *, int, struct scsi_cmnd *,
struct zfcp_fsf_req *);
extern void zfcp_dbf_scsi_eh(char *tag, struct zfcp_adapter *adapter,
unsigned int scsi_id, int ret);
/* zfcp_erp.c */
extern void zfcp_erp_set_adapter_status(struct zfcp_adapter *, u32);

11
drivers/s390/scsi/zfcp_scsi.c
View File

@ -323,15 +323,16 @@ static int zfcp_scsi_eh_host_reset_handler(struct scsi_cmnd *scpnt)
{
struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(scpnt->device);
struct zfcp_adapter *adapter = zfcp_sdev->port->adapter;
int ret;
int ret = SUCCESS, fc_ret;
zfcp_erp_adapter_reopen(adapter, 0, "schrh_1");
zfcp_erp_wait(adapter);
ret = fc_block_scsi_eh(scpnt);
if (ret)
return ret;
fc_ret = fc_block_scsi_eh(scpnt);
if (fc_ret)
ret = fc_ret;
return SUCCESS;
zfcp_dbf_scsi_eh("schrh_r", adapter, ~0, ret);
return ret;
}
struct scsi_transport_template *zfcp_scsi_transport_template;