[PATCH] remove scsi_cmnd->state

[Christoph Hellwig <hch@lst.de>]

We never look at it except for the old megaraid driver that abuses it
for sending internal commands.  That usage can be fixed easily because
thos internal commands are single-threaded by a mutex and we can easily
use a completion there.


Index: linux-2.6/drivers/scsi/megaraid.c
===================================================================
--- linux-2.6.orig/drivers/scsi/megaraid.c	2005-06-19 12:27:27.000000000 +0200
+++ linux-2.6/drivers/scsi/megaraid.c	2005-06-19 12:29:53.000000000 +0200
@@ -35,6 +35,7 @@
 #include <linux/blkdev.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
+#include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/proc_fs.h>
 #include <linux/reboot.h>
@@ -4490,8 +4491,6 @@
 
 	scb->idx = CMDID_INT_CMDS;
 
-	scmd->state = 0;
-
 	/*
 	 * Get the lock only if the caller has not acquired it already
 	 */
@@ -4501,15 +4500,7 @@
 
 	if( ls == LOCK_INT ) spin_unlock_irqrestore(&adapter->lock, flags);
 
-	/*
-	 * Wait till this command finishes. Do not use
-	 * wait_event_interruptible(). It causes panic if CTRL-C is hit when
-	 * dumping e.g., physical disk information through /proc interface.
-	 */
-#if 0
-	wait_event_interruptible(adapter->int_waitq, scmd->state);
-#endif
-	wait_event(adapter->int_waitq, scmd->state);
+	wait_for_completion(&adapter->int_waitq);
 
 	rval = scmd->result;
 	mc->status = scmd->result;
@@ -4543,16 +4534,7 @@
 
 	adapter = (adapter_t *)scmd->device->host->hostdata;
 
-	scmd->state = 1; /* thread waiting for its command to complete */
-
-	/*
-	 * See comment in mega_internal_command() routine for
-	 * wait_event_interruptible()
-	 */
-#if 0
-	wake_up_interruptible(&adapter->int_waitq);
-#endif
-	wake_up(&adapter->int_waitq);
+	complete(&adapter->int_waitq);
 
 }
 
@@ -4874,7 +4856,7 @@
 	}
 		
 	init_MUTEX(&adapter->int_mtx);
-	init_waitqueue_head(&adapter->int_waitq);
+	init_completion(&adapter->int_waitq);
 
 	adapter->this_id = DEFAULT_INITIATOR_ID;
 	adapter->host->this_id = DEFAULT_INITIATOR_ID;
Index: linux-2.6/drivers/scsi/megaraid.h
===================================================================
--- linux-2.6.orig/drivers/scsi/megaraid.h	2005-06-19 12:27:27.000000000 +0200
+++ linux-2.6/drivers/scsi/megaraid.h	2005-06-19 12:28:08.000000000 +0200
@@ -891,7 +891,7 @@
 	Scsi_Cmnd		int_scmd;
 	struct semaphore	int_mtx;	/* To synchronize the internal
 						commands */
-	wait_queue_head_t	int_waitq;	/* wait queue for internal
+	struct completion	int_waitq;	/* wait queue for internal
 						 cmds */
 
 	int	has_cluster;	/* cluster support on this HBA */
Index: linux-2.6/drivers/scsi/scsi.c
===================================================================
--- linux-2.6.orig/drivers/scsi/scsi.c	2005-06-19 12:28:07.000000000 +0200
+++ linux-2.6/drivers/scsi/scsi.c	2005-06-19 12:28:08.000000000 +0200
@@ -257,7 +257,6 @@
 
 		memset(cmd, 0, sizeof(*cmd));
 		cmd->device = dev;
-		cmd->state = SCSI_STATE_UNUSED;
 		init_timer(&cmd->eh_timeout);
 		INIT_LIST_HEAD(&cmd->list);
 		spin_lock_irqsave(&dev->list_lock, flags);
@@ -607,9 +606,6 @@
 	 * We will use a queued command if possible, otherwise we will
 	 * emulate the queuing and calling of completion function ourselves.
 	 */
-
-	cmd->state = SCSI_STATE_QUEUED;
-
 	atomic_inc(&cmd->device->iorequest_cnt);
 
 	/*
@@ -762,7 +758,6 @@
 	 * Set the serial numbers back to zero
 	 */
 	cmd->serial_number = 0;
-	cmd->state = SCSI_STATE_BHQUEUE;
 
 	atomic_inc(&cmd->device->iodone_cnt);
 	if (cmd->result)
@@ -883,8 +878,6 @@
 	SCSI_LOG_MLCOMPLETE(4, printk("Notifying upper driver of completion "
 				"for device %d %x\n", sdev->id, cmd->result));
 
-	cmd->state = SCSI_STATE_FINISHED;
-
 	/*
 	 * We can get here with use_sg=0, causing a panic in the upper level
 	 */
Index: linux-2.6/drivers/scsi/scsi_error.c
===================================================================
--- linux-2.6.orig/drivers/scsi/scsi_error.c	2005-06-19 12:28:07.000000000 +0200
+++ linux-2.6/drivers/scsi/scsi_error.c	2005-06-19 12:29:22.000000000 +0200
@@ -74,10 +74,6 @@
 	spin_lock_irqsave(shost->host_lock, flags);
 
 	scsi_eh_eflags_set(scmd, eh_flag);
-	/*
-	 * FIXME: Can we stop setting owner and state.
-	 */
-	scmd->state = SCSI_STATE_FAILED;
 	list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
 	set_bit(SHOST_RECOVERY, &shost->shost_state);
 	shost->host_failed++;
@@ -634,8 +630,6 @@
 			       struct list_head *done_q)
 {
 	scmd->device->host->host_failed--;
-	scmd->state = SCSI_STATE_BHQUEUE;
-
 	scsi_eh_eflags_clr_all(scmd);
 
 	/*
@@ -1803,7 +1797,6 @@
 	scmd->request = &req;
 	memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout));
 	scmd->request->rq_status      	= RQ_SCSI_BUSY;
-	scmd->state                   	= SCSI_STATE_INITIALIZING;
 
 	memset(&scmd->cmnd, '\0', sizeof(scmd->cmnd));
     
Index: linux-2.6/drivers/scsi/scsi_lib.c
===================================================================
--- linux-2.6.orig/drivers/scsi/scsi_lib.c	2005-06-19 12:28:07.000000000 +0200
+++ linux-2.6/drivers/scsi/scsi_lib.c	2005-06-19 12:28:08.000000000 +0200
@@ -146,11 +146,6 @@
 		device->device_blocked = device->max_device_blocked;
 
 	/*
-	 * Register the fact that we own the thing for now.
-	 */
-	cmd->state = SCSI_STATE_MLQUEUE;
-
-	/*
 	 * Decrement the counters, since these commands are no longer
 	 * active on the host/device.
 	 */
Index: linux-2.6/include/scsi/scsi_cmnd.h
===================================================================
--- linux-2.6.orig/include/scsi/scsi_cmnd.h	2005-06-19 12:28:07.000000000 +0200
+++ linux-2.6/include/scsi/scsi_cmnd.h	2005-06-19 12:28:08.000000000 +0200
@@ -31,7 +31,6 @@
 	int     sc_magic;
 
 	struct scsi_device *device;
-	unsigned short state;
 	struct scsi_request *sc_request;
 
 	struct list_head list;  /* scsi_cmnd participates in queue lists */