From f2b9857eee17797541b845782ade4d7a9d50f843 Mon Sep 17 00:00:00 2001
From: Jonathan Corbet <corbet@lwn.net>
Date: Sun, 18 May 2008 15:32:43 -0600
Subject: Add a bunch of cycle_kernel_lock() calls

All of the open() functions which don't need the BKL on their face may
still depend on its acquisition to serialize opens against driver
initialization.  So make those functions acquire then release the BKL to be
on the safe side.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
---
 drivers/scsi/3w-9xxx.c               | 5 +++--
 drivers/scsi/3w-xxxx.c               | 5 +++--
 drivers/scsi/megaraid.c              | 4 ++--
 drivers/scsi/megaraid/megaraid_sas.c | 3 ++-
 4 files changed, 10 insertions(+), 7 deletions(-)

(limited to 'drivers/scsi')

diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
index 2239d16fb9b5..eaa805df5b00 100644
--- a/drivers/scsi/3w-9xxx.c
+++ b/drivers/scsi/3w-9xxx.c
@@ -84,6 +84,7 @@
 #include <linux/pci.h>
 #include <linux/time.h>
 #include <linux/mutex.h>
+#include <linux/smp_lock.h>
 #include <asm/io.h>
 #include <asm/irq.h>
 #include <asm/uaccess.h>
@@ -862,13 +863,13 @@ out:
 } /* End twa_chrdev_ioctl() */
 
 /* This function handles open for the character device */
-/* NOTE that this function will race with remove; adding BKL
-   will not help. */
+/* NOTE that this function will race with remove. */
 static int twa_chrdev_open(struct inode *inode, struct file *file)
 {
 	unsigned int minor_number;
 	int retval = TW_IOCTL_ERROR_OS_ENODEV;
 
+	cycle_kernel_lock();
 	minor_number = iminor(inode);
 	if (minor_number >= twa_device_extension_count)
 		goto out;
diff --git a/drivers/scsi/3w-xxxx.c b/drivers/scsi/3w-xxxx.c
index bbff029536ea..a0537f09aa21 100644
--- a/drivers/scsi/3w-xxxx.c
+++ b/drivers/scsi/3w-xxxx.c
@@ -198,6 +198,7 @@
 
 #include <linux/module.h>
 #include <linux/reboot.h>
+#include <linux/smp_lock.h>
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
 #include <linux/moduleparam.h>
@@ -1027,12 +1028,12 @@ out:
 } /* End tw_chrdev_ioctl() */
 
 /* This function handles open for the character device */
-/* NOTE that this function races with remove - adding BKL
-   won't help */
+/* NOTE that this function races with remove. */
 static int tw_chrdev_open(struct inode *inode, struct file *file)
 {
 	unsigned int minor_number;
 
+	cycle_kernel_lock();
 	dprintk(KERN_WARNING "3w-xxxx: tw_ioctl_open()\n");
 
 	minor_number = iminor(inode);
diff --git a/drivers/scsi/megaraid.c b/drivers/scsi/megaraid.c
index c9aa2c45a699..28c9da7d4a5c 100644
--- a/drivers/scsi/megaraid.c
+++ b/drivers/scsi/megaraid.c
@@ -46,6 +46,7 @@
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/dma-mapping.h>
+#include <linux/smp_lock.h>
 #include <scsi/scsicam.h>
 
 #include "scsi.h"
@@ -3273,12 +3274,11 @@ mega_init_scb(adapter_t *adapter)
  *
  * Routines for the character/ioctl interface to the driver. Find out if this
  * is a valid open. 
- *
- * No BKL needed here.
  */
 static int
 megadev_open (struct inode *inode, struct file *filep)
 {
+	cycle_kernel_lock();
 	/*
 	 * Only allow superuser to access private ioctl interface
 	 */
diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index 81374b7c555c..fc7ac158476c 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -33,6 +33,7 @@
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
+#include <linux/smp_lock.h>
 #include <linux/uio.h>
 #include <asm/uaccess.h>
 #include <linux/fs.h>
@@ -2860,10 +2861,10 @@ static void megasas_shutdown(struct pci_dev *pdev)
 
 /**
  * megasas_mgmt_open -	char node "open" entry point
- * No BKL is needed here.
  */
 static int megasas_mgmt_open(struct inode *inode, struct file *filep)
 {
+	cycle_kernel_lock();
 	/*
 	 * Allow only those users with admin rights
 	 */
-- 
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