[SCSI] host state model update: reimplement scsi_host_cancel

Remove the old scsi_host_cancel function as it has not been working for
sometime do to the device list possibly being empty when it is called and
possible race issues. Add setting of SHOST_CANCEL at the state of beginning
of scsi_remove_host.

Signed-off-by: Mike Anderson <andmike@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/hosts.c

@@ -127,30 +127,14 @@ int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
 }
 EXPORT_SYMBOL(scsi_host_set_state);
 
-/**
- * scsi_host_cancel - cancel outstanding IO to this host
- * @shost:	pointer to struct Scsi_Host
- * recovery:	recovery requested to run.
- **/
-static void scsi_host_cancel(struct Scsi_Host *shost, int recovery)
-{
-	struct scsi_device *sdev;
-
-	scsi_host_set_state(shost, SHOST_CANCEL);
-	shost_for_each_device(sdev, shost) {
-		scsi_device_cancel(sdev, recovery);
-	}
-	wait_event(shost->host_wait, (shost->shost_state != SHOST_RECOVERY));
-}
-
 /**
  * scsi_remove_host - remove a scsi host
  * @shost:	a pointer to a scsi host to remove
  **/
 void scsi_remove_host(struct Scsi_Host *shost)
 {
+	scsi_host_set_state(shost, SHOST_CANCEL);
 	scsi_forget_host(shost);
-	scsi_host_cancel(shost, 0);
 	scsi_proc_host_rm(shost);
 
 	scsi_host_set_state(shost, SHOST_DEL);

drivers/scsi/scsi.c

@@ -627,7 +627,7 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 	spin_lock_irqsave(host->host_lock, flags);
 	scsi_cmd_get_serial(host, cmd); 
 
-	if (unlikely(host->shost_state == SHOST_CANCEL)) {
+	if (unlikely(host->shost_state == SHOST_DEL)) {
 		cmd->result = (DID_NO_CONNECT << 16);
 		scsi_done(cmd);
 	} else {