Re: [PATCH scsi-misc-2.6 06/08] scsi: remove meaningless scsi_cmnd->serial_number_at_timeout field

Tejun Heo
2005-03-23T02:24:06Z

06_scsi_remove_serial_number_at_timeout.patch

scsi_cmnd->serial_number_at_timeout doesn't serve any purpose
anymore. All serial_number == serial_number_at_timeout tests
are always true in abort callbacks. Kill the field. Also, as
->pid always equals ->serial_number and ->serial_number
doesn't have any special meaning anymore, update comments
above ->serial_number accordingly. Once we remove all uses of
this field from all lldd's, this field should go.

Signed-off-by: Tejun Heo <htejun@gmail.com>

drivers/scsi/BusLogic.c | 7 -------
drivers/scsi/advansys.c | 5 ++---
drivers/scsi/ips.c | 7 -------
drivers/scsi/ncr53c8xx.c | 14 ++------------
drivers/scsi/qla2xxx/qla_dbg.c | 6 ++----
drivers/scsi/scsi.c | 2 --
drivers/scsi/scsi_error.c | 7 -------
drivers/scsi/scsi_lib.c | 1 -
drivers/scsi/sym53c8xx_2/sym_glue.c | 6 ------
include/scsi/scsi_cmnd.h | 22 +++++++++-------------
10 files changed, 15 insertions(+), 62 deletions(-)

Index: scsi-export/drivers/scsi/BusLogic.c
===================================================================
--- scsi-export.orig/drivers/scsi/BusLogic.c 2005-03-23 09:39:36.000000000 +0900
+++ scsi-export/drivers/scsi/BusLogic.c 2005-03-23 09:40:11.000000000 +0900
@@ -2958,13 +2958,6 @@ static int BusLogic_AbortCommand(struct
struct BusLogic_CCB *CCB;
BusLogic_IncrementErrorCounter(&HostAdapter->TargetStatistics[TargetID].CommandAbortsRequested);
/*
- If this Command has already completed, then no Abort is necessary.
- */
- if (Command->serial_number != Command->serial_number_at_timeout) {
- BusLogic_Warning("Unable to Abort Command to Target %d - " "Already Completed\n", HostAdapter, TargetID);
- return SUCCESS;
- }
- /*
Attempt to find an Active CCB for this Command. If no Active CCB for this
Command is found, then no Abort is necessary.
*/
Index: scsi-export/drivers/scsi/advansys.c
===================================================================
--- scsi-export.orig/drivers/scsi/advansys.c 2005-03-23 09:40:09.000000000 +0900
+++ scsi-export/drivers/scsi/advansys.c 2005-03-23 09:40:11.000000000 +0900
@@ -9198,9 +9198,8 @@ asc_prt_scsi_cmnd(struct scsi_cmnd *s)
s->use_sg, s->sglist_len, s->abort_reason);

printk(
-" serial_number 0x%x, serial_number_at_timeout 0x%x, retries %d, allowed %d\n",
- (unsigned) s->serial_number, (unsigned) s->serial_number_at_timeout,
- s->retries, s->allowed);
+" serial_number 0x%x, retries %d, allowed %d\n",
+ (unsigned) s->serial_number, s->retries, s->allowed);

printk(
" timeout_per_command %d, timeout_total %d, timeout %d\n",
Index: scsi-export/drivers/scsi/ips.c
===================================================================
--- scsi-export.orig/drivers/scsi/ips.c 2005-03-23 09:39:36.000000000 +0900
+++ scsi-export/drivers/scsi/ips.c 2005-03-23 09:40:11.000000000 +0900
@@ -833,13 +833,6 @@ ips_eh_abort(Scsi_Cmnd * SC)
if (!ha->active)
return (FAILED);

- if (SC->serial_number != SC->serial_number_at_timeout) {
- /* HMM, looks like a bogus command */
- DEBUG(1, "Abort called with bogus scsi command");
-
- return (FAILED);
- }
-
/* See if the command is on the copp queue */
item = ha->copp_waitlist.head;
while ((item) && (item->scsi_cmd != SC))
Index: scsi-export/drivers/scsi/ncr53c8xx.c
===================================================================
--- scsi-export.orig/drivers/scsi/ncr53c8xx.c 2005-03-23 09:39:36.000000000 +0900
+++ scsi-export/drivers/scsi/ncr53c8xx.c 2005-03-23 09:40:11.000000000 +0900
@@ -7601,24 +7601,14 @@ static int ncr53c8xx_abort(struct scsi_c
struct scsi_cmnd *done_list;

#if defined SCSI_RESET_SYNCHRONOUS && defined SCSI_RESET_ASYNCHRONOUS
- printk("ncr53c8xx_abort: pid=%lu serial_number=%ld serial_number_at_timeout=%ld\n",
- cmd->pid, cmd->serial_number, cmd->serial_number_at_timeout);
+ printk("ncr53c8xx_abort: pid=%lu serial_number=%ld\n",
+ cmd->pid, cmd->serial_number);
#else
printk("ncr53c8xx_abort: command pid %lu\n", cmd->pid);
#endif

NCR_LOCK_NCB(np, flags);

-#if defined SCSI_RESET_SYNCHRONOUS && defined SCSI_RESET_ASYNCHRONOUS
- /*
- * We have to just ignore abort requests in some situations.
- */
- if (cmd->serial_number != cmd->serial_number_at_timeout) {
- sts = SCSI_ABORT_NOT_RUNNING;
- goto out;
- }
-#endif
-
sts = ncr_abort_command(np, cmd);
out:
done_list = np->done_list;
Index: scsi-export/drivers/scsi/qla2xxx/qla_dbg.c
===================================================================
--- scsi-export.orig/drivers/scsi/qla2xxx/qla_dbg.c 2005-03-23 09:39:36.000000000 +0900
+++ scsi-export/drivers/scsi/qla2xxx/qla_dbg.c 2005-03-23 09:40:11.000000000 +0900
@@ -1050,10 +1050,8 @@ qla2x00_print_scsi_cmd(struct scsi_cmnd
for (i = 0; i < cmd->cmd_len; i++) {
printk("0x%02x ", cmd->cmnd[i]);
}
- printk("\n seg_cnt=%d, allowed=%d, retries=%d, "
- "serial_number_at_timeout=0x%lx\n",
- cmd->use_sg, cmd->allowed, cmd->retries,
- cmd->serial_number_at_timeout);
+ printk("\n seg_cnt=%d, allowed=%d, retries=%d\n",
+ cmd->use_sg, cmd->allowed, cmd->retries);
printk(" request buffer=0x%p, request buffer len=0x%x\n",
cmd->request_buffer, cmd->request_bufflen);
printk(" tag=%d, transfersize=0x%x\n",
Index: scsi-export/drivers/scsi/scsi.c
===================================================================
--- scsi-export.orig/drivers/scsi/scsi.c 2005-03-23 09:40:10.000000000 +0900
+++ scsi-export/drivers/scsi/scsi.c 2005-03-23 09:40:11.000000000 +0900
@@ -687,7 +687,6 @@ void scsi_init_cmd_from_req(struct scsi_
cmd->request = sreq->sr_request;
memcpy(cmd->data_cmnd, sreq->sr_cmnd, sizeof(cmd->data_cmnd));
cmd->serial_number = 0;
- cmd->serial_number_at_timeout = 0;
cmd->bufflen = sreq->sr_bufflen;
cmd->buffer = sreq->sr_buffer;
cmd->retries = 0;
@@ -766,7 +765,6 @@ void __scsi_done(struct scsi_cmnd *cmd)
* Set the serial numbers back to zero
*/
cmd->serial_number = 0;
- cmd->serial_number_at_timeout = 0;
cmd->state = SCSI_STATE_BHQUEUE;
cmd->owner = SCSI_OWNER_BH_HANDLER;

Index: scsi-export/drivers/scsi/scsi_error.c
===================================================================
--- scsi-export.orig/drivers/scsi/scsi_error.c 2005-03-23 09:40:10.000000000 +0900
+++ scsi-export/drivers/scsi/scsi_error.c 2005-03-23 09:40:11.000000000 +0900
@@ -80,11 +80,6 @@ int scsi_eh_scmd_add(struct scsi_cmnd *s
*/
scmd->owner = SCSI_OWNER_ERROR_HANDLER;
scmd->state = SCSI_STATE_FAILED;
- /*
- * Set the serial_number_at_timeout to the current
- * serial_number
- */
- scmd->serial_number_at_timeout = scmd->serial_number;
list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
set_bit(SHOST_RECOVERY, &shost->shost_state);
shost->host_failed++;
@@ -1060,7 +1055,6 @@ static int scsi_try_bus_reset(struct scs
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n",
__FUNCTION__));
scmd->owner = SCSI_OWNER_LOWLEVEL;
- scmd->serial_number_at_timeout = scmd->serial_number;

if (!scmd->device->host->hostt->eh_bus_reset_handler)
return FAILED;
@@ -1092,7 +1086,6 @@ static int scsi_try_host_reset(struct sc
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n",
__FUNCTION__));
scmd->owner = SCSI_OWNER_LOWLEVEL;
- scmd->serial_number_at_timeout = scmd->serial_number;

if (!scmd->device->host->hostt->eh_host_reset_handler)
return FAILED;
Index: scsi-export/drivers/scsi/scsi_lib.c
===================================================================
--- scsi-export.orig/drivers/scsi/scsi_lib.c 2005-03-23 09:40:10.000000000 +0900
+++ scsi-export/drivers/scsi/scsi_lib.c 2005-03-23 09:40:11.000000000 +0900
@@ -386,7 +386,6 @@ static int scsi_init_cmd_errh(struct scs
{
cmd->owner = SCSI_OWNER_MIDLEVEL;
cmd->serial_number = 0;
- cmd->serial_number_at_timeout = 0;
cmd->abort_reason = 0;

memset(cmd->sense_buffer, 0, sizeof cmd->sense_buffer);
Index: scsi-export/drivers/scsi/sym53c8xx_2/sym_glue.c
===================================================================
--- scsi-export.orig/drivers/scsi/sym53c8xx_2/sym_glue.c 2005-03-23 09:39:36.000000000 +0900
+++ scsi-export/drivers/scsi/sym53c8xx_2/sym_glue.c 2005-03-23 09:40:11.000000000 +0900
@@ -799,12 +799,6 @@ static int sym_eh_handler(int op, char *

dev_warn(&cmd->device->sdev_gendev, "%s operation started.\n", opname);

-#if 0
- /* This one should be the result of some race, thus to ignore */
- if (cmd->serial_number != cmd->serial_number_at_timeout)
- goto prepare;
-#endif
-
/* This one is queued in some place -> to wait for completion */
FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
struct sym_ccb *cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
Index: scsi-export/include/scsi/scsi_cmnd.h
===================================================================
--- scsi-export.orig/include/scsi/scsi_cmnd.h 2005-03-23 09:40:09.000000000 +0900
+++ scsi-export/include/scsi/scsi_cmnd.h 2005-03-23 09:40:11.000000000 +0900
@@ -43,21 +43,17 @@ struct scsi_cmnd {
void (*done) (struct scsi_cmnd *); /* Mid-level done function */

/*
- * A SCSI Command is assigned a nonzero serial_number when internal_cmnd
- * passes it to the driver's queue command function. The serial_number
- * is cleared when scsi_done is entered indicating that the command has
- * been completed. If a timeout occurs, the serial number at the moment
- * of timeout is copied into serial_number_at_timeout. By subsequently
- * comparing the serial_number and serial_number_at_timeout fields
- * during abort or reset processing, we can detect whether the command
- * has already completed. This also detects cases where the command has
- * completed and the SCSI Command structure has already being reused
- * for another command, so that we can avoid incorrectly aborting or
- * resetting the new command.
- * The serial number is only unique per host.
+ * A SCSI Command is assigned a nonzero serial_number before passed
+ * to the driver's queue command function. The serial_number is
+ * cleared when scsi_done is entered indicating that the command
+ * has been completed. It currently doesn't have much use other
+ * than printk's. Some lldd's use this number for other purposes.
+ * It's almost certain that such usages are either incorrect or
+ * meaningless. Please kill all usages other than printk's. Also,
+ * as this number is always identical to ->pid, please convert
+ * printk's to use ->pid, so that we can kill this field.
*/
unsigned long serial_number;
- unsigned long serial_number_at_timeout;

int retries;
int allowed;