[SCSI] zfcp: remove union zfcp_req_data, use unit refcount for FCP commands
o union zfcp_req_data removed
o increment unit refcount when processing FCP commands
(This fixes a theoretical race: When all scsi commands of a unit
are aborted and the scsi_device is removed then the unit could be
removed before all fsf_requests of that unit are completely processed.)
Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index 31a7606..fffd123 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -414,67 +414,37 @@
return (struct zfcp_port *) NULL;
}
-/*
- * function: zfcp_scsi_eh_abort_handler
+/**
+ * zfcp_scsi_eh_abort_handler - abort the specified SCSI command
+ * @scpnt: pointer to scsi_cmnd to be aborted
+ * Return: SUCCESS - command has been aborted and cleaned up in internal
+ * bookkeeping, SCSI stack won't be called for aborted command
+ * FAILED - otherwise
*
- * purpose: tries to abort the specified (timed out) SCSI command
- *
- * note: We do not need to care for a SCSI command which completes
- * normally but late during this abort routine runs.
- * We are allowed to return late commands to the SCSI stack.
- * It tracks the state of commands and will handle late commands.
- * (Usually, the normal completion of late commands is ignored with
- * respect to the running abort operation. Grep for 'done_late'
- * in the SCSI stacks sources.)
- *
- * returns: SUCCESS - command has been aborted and cleaned up in internal
- * bookkeeping,
- * SCSI stack won't be called for aborted command
- * FAILED - otherwise
+ * We do not need to care for a SCSI command which completes normally
+ * but late during this abort routine runs. We are allowed to return
+ * late commands to the SCSI stack. It tracks the state of commands and
+ * will handle late commands. (Usually, the normal completion of late
+ * commands is ignored with respect to the running abort operation.)
*/
int
-__zfcp_scsi_eh_abort_handler(struct scsi_cmnd *scpnt)
+zfcp_scsi_eh_abort_handler(struct scsi_cmnd *scpnt)
{
+ struct Scsi_Host *scsi_host;
+ struct zfcp_adapter *adapter;
+ struct zfcp_unit *unit;
int retval = SUCCESS;
struct zfcp_fsf_req *new_fsf_req, *old_fsf_req;
- struct zfcp_adapter *adapter = (struct zfcp_adapter *) scpnt->device->host->hostdata[0];
- struct zfcp_unit *unit = (struct zfcp_unit *) scpnt->device->hostdata;
- struct zfcp_port *port = unit->port;
- struct Scsi_Host *scsi_host = scpnt->device->host;
- union zfcp_req_data *req_data = NULL;
unsigned long flags;
- u32 status = 0;
- /* the components of a abort_dbf record (fixed size record) */
- u64 dbf_scsi_cmnd = (unsigned long) scpnt;
- char dbf_opcode[ZFCP_ABORT_DBF_LENGTH];
- wwn_t dbf_wwn = port->wwpn;
- fcp_lun_t dbf_fcp_lun = unit->fcp_lun;
- u64 dbf_retries = scpnt->retries;
- u64 dbf_allowed = scpnt->allowed;
- u64 dbf_timeout = 0;
- u64 dbf_fsf_req = 0;
- u64 dbf_fsf_status = 0;
- u64 dbf_fsf_qual[2] = { 0, 0 };
- char dbf_result[ZFCP_ABORT_DBF_LENGTH] = "##undef";
-
- memset(dbf_opcode, 0, ZFCP_ABORT_DBF_LENGTH);
- memcpy(dbf_opcode,
- scpnt->cmnd,
- min(scpnt->cmd_len, (unsigned char) ZFCP_ABORT_DBF_LENGTH));
+ scsi_host = scpnt->device->host;
+ adapter = (struct zfcp_adapter *) scsi_host->hostdata[0];
+ unit = (struct zfcp_unit *) scpnt->device->hostdata;
ZFCP_LOG_INFO("aborting scsi_cmnd=%p on adapter %s\n",
scpnt, zfcp_get_busid_by_adapter(adapter));
- spin_unlock_irq(scsi_host->host_lock);
-
- /*
- * Race condition between normal (late) completion and abort has
- * to be avoided.
- * The entirity of all accesses to scsi_req have to be atomic.
- * scsi_req is usually part of the fsf_req and thus we block the
- * release of fsf_req as long as we need to access scsi_req.
- */
+ /* avoid race condition between late normal completion and abort */
write_lock_irqsave(&adapter->abort_lock, flags);
/*
@@ -484,144 +454,48 @@
* this routine returns. (scpnt is parameter passed to this routine
* and must not disappear during abort even on late completion.)
*/
- req_data = (union zfcp_req_data *) scpnt->host_scribble;
- /* DEBUG */
- ZFCP_LOG_DEBUG("req_data=%p\n", req_data);
- if (!req_data) {
- ZFCP_LOG_DEBUG("late command completion overtook abort\n");
- /*
- * That's it.
- * Do not initiate abort but return SUCCESS.
- */
- write_unlock_irqrestore(&adapter->abort_lock, flags);
- retval = SUCCESS;
- strncpy(dbf_result, "##late1", ZFCP_ABORT_DBF_LENGTH);
- goto out;
- }
-
- /* Figure out which fsf_req needs to be aborted. */
- old_fsf_req = req_data->send_fcp_command_task.fsf_req;
-
- dbf_fsf_req = (unsigned long) old_fsf_req;
- dbf_timeout =
- (jiffies - req_data->send_fcp_command_task.start_jiffies) / HZ;
-
- ZFCP_LOG_DEBUG("old_fsf_req=%p\n", old_fsf_req);
+ old_fsf_req = (struct zfcp_fsf_req *) scpnt->host_scribble;
if (!old_fsf_req) {
write_unlock_irqrestore(&adapter->abort_lock, flags);
ZFCP_LOG_NORMAL("bug: no old fsf request found\n");
- ZFCP_LOG_NORMAL("req_data:\n");
- ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_NORMAL,
- (char *) req_data, sizeof (union zfcp_req_data));
ZFCP_LOG_NORMAL("scsi_cmnd:\n");
ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_NORMAL,
(char *) scpnt, sizeof (struct scsi_cmnd));
retval = FAILED;
- strncpy(dbf_result, "##bug:r", ZFCP_ABORT_DBF_LENGTH);
goto out;
}
- old_fsf_req->data.send_fcp_command_task.scsi_cmnd = NULL;
- /* mark old request as being aborted */
+ old_fsf_req->data = 0;
old_fsf_req->status |= ZFCP_STATUS_FSFREQ_ABORTING;
- /*
- * We have to collect all information (e.g. unit) needed by
- * zfcp_fsf_abort_fcp_command before calling that routine
- * since that routine is not allowed to access
- * fsf_req which it is going to abort.
- * This is because of we need to release fsf_req_list_lock
- * before calling zfcp_fsf_abort_fcp_command.
- * Since this lock will not be held, fsf_req may complete
- * late and may be released meanwhile.
- */
- ZFCP_LOG_DEBUG("unit 0x%016Lx (%p)\n", unit->fcp_lun, unit);
- /*
- * We block (call schedule)
- * That's why we must release the lock and enable the
- * interrupts before.
- * On the other hand we do not need the lock anymore since
- * all critical accesses to scsi_req are done.
- */
+ /* don't access old_fsf_req after releasing the abort_lock */
write_unlock_irqrestore(&adapter->abort_lock, flags);
/* call FSF routine which does the abort */
new_fsf_req = zfcp_fsf_abort_fcp_command((unsigned long) old_fsf_req,
adapter, unit, 0);
- ZFCP_LOG_DEBUG("new_fsf_req=%p\n", new_fsf_req);
if (!new_fsf_req) {
retval = FAILED;
ZFCP_LOG_NORMAL("error: initiation of Abort FCP Cmnd "
"failed\n");
- strncpy(dbf_result, "##nores", ZFCP_ABORT_DBF_LENGTH);
goto out;
}
/* wait for completion of abort */
- ZFCP_LOG_DEBUG("waiting for cleanup...\n");
-#if 1
- /*
- * FIXME:
- * copying zfcp_fsf_req_wait_and_cleanup code is not really nice
- */
__wait_event(new_fsf_req->completion_wq,
new_fsf_req->status & ZFCP_STATUS_FSFREQ_COMPLETED);
- status = new_fsf_req->status;
- dbf_fsf_status = new_fsf_req->qtcb->header.fsf_status;
- /*
- * Ralphs special debug load provides timestamps in the FSF
- * status qualifier. This might be specified later if being
- * useful for debugging aborts.
- */
- dbf_fsf_qual[0] =
- *(u64 *) & new_fsf_req->qtcb->header.fsf_status_qual.word[0];
- dbf_fsf_qual[1] =
- *(u64 *) & new_fsf_req->qtcb->header.fsf_status_qual.word[2];
zfcp_fsf_req_free(new_fsf_req);
-#else
- retval = zfcp_fsf_req_wait_and_cleanup(new_fsf_req,
- ZFCP_UNINTERRUPTIBLE, &status);
-#endif
- ZFCP_LOG_DEBUG("Waiting for cleanup complete, status=0x%x\n", status);
+
/* status should be valid since signals were not permitted */
- if (status & ZFCP_STATUS_FSFREQ_ABORTSUCCEEDED) {
+ if (new_fsf_req->status & ZFCP_STATUS_FSFREQ_ABORTSUCCEEDED) {
retval = SUCCESS;
- strncpy(dbf_result, "##succ", ZFCP_ABORT_DBF_LENGTH);
- } else if (status & ZFCP_STATUS_FSFREQ_ABORTNOTNEEDED) {
+ } else if (new_fsf_req->status & ZFCP_STATUS_FSFREQ_ABORTNOTNEEDED) {
retval = SUCCESS;
- strncpy(dbf_result, "##late2", ZFCP_ABORT_DBF_LENGTH);
} else {
retval = FAILED;
- strncpy(dbf_result, "##fail", ZFCP_ABORT_DBF_LENGTH);
}
-
out:
- debug_event(adapter->abort_dbf, 1, &dbf_scsi_cmnd, sizeof (u64));
- debug_event(adapter->abort_dbf, 1, &dbf_opcode, ZFCP_ABORT_DBF_LENGTH);
- debug_event(adapter->abort_dbf, 1, &dbf_wwn, sizeof (wwn_t));
- debug_event(adapter->abort_dbf, 1, &dbf_fcp_lun, sizeof (fcp_lun_t));
- debug_event(adapter->abort_dbf, 1, &dbf_retries, sizeof (u64));
- debug_event(adapter->abort_dbf, 1, &dbf_allowed, sizeof (u64));
- debug_event(adapter->abort_dbf, 1, &dbf_timeout, sizeof (u64));
- debug_event(adapter->abort_dbf, 1, &dbf_fsf_req, sizeof (u64));
- debug_event(adapter->abort_dbf, 1, &dbf_fsf_status, sizeof (u64));
- debug_event(adapter->abort_dbf, 1, &dbf_fsf_qual[0], sizeof (u64));
- debug_event(adapter->abort_dbf, 1, &dbf_fsf_qual[1], sizeof (u64));
- debug_text_event(adapter->abort_dbf, 1, dbf_result);
-
- spin_lock_irq(scsi_host->host_lock);
return retval;
}
-int
-zfcp_scsi_eh_abort_handler(struct scsi_cmnd *scpnt)
-{
- int rc;
- struct Scsi_Host *scsi_host = scpnt->device->host;
- spin_lock_irq(scsi_host->host_lock);
- rc = __zfcp_scsi_eh_abort_handler(scpnt);
- spin_unlock_irq(scsi_host->host_lock);
- return rc;
-}
-
/*
* function: zfcp_scsi_eh_device_reset_handler
*