scsi: autoconvert trivial BKL users to private mutex

All these files use the big kernel lock in a trivial
way to serialize their private file operations,
typically resulting from an earlier semi-automatic
pushdown from VFS.

None of these drivers appears to want to lock against
other code, and they all use the BKL as the top-level
lock in their file operations, meaning that there
is no lock-order inversion problem.

Consequently, we can remove the BKL completely,
replacing it with a per-file mutex in every case.
Using a scripted approach means we can avoid
typos.

file=$1
name=$2
if grep -q lock_kernel ${file} ; then
    if grep -q 'include.*linux.mutex.h' ${file} ; then
            sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
    else
            sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
    fi
    sed -i ${file} \
        -e "/^#include.*linux.mutex.h/,$ {
                1,/^\(static\|int\|long\)/ {
                     /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);

} }"  \
    -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
    -e '/[      ]*cycle_kernel_lock();/d'
else
    sed -i -e '/include.*\<smp_lock.h\>/d' ${file}  \
                -e '/cycle_kernel_lock()/d'
fi

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: linux-scsi@vger.kernel.org
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>

1 files changed, 4 insertions, 5 deletions

diff --git a/drivers/scsi/3w-xxxx.c b/drivers/scsi/3w-xxxx.c
index 30d735ad35b..081c864c11d 100644
--- a/drivers/scsi/3w-xxxx.c
+++ b/drivers/scsi/3w-xxxx.c
@@ -199,7 +199,6 @@
 
 #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>
@@ -221,6 +220,7 @@
 
 /* Globals */
 #define TW_DRIVER_VERSION "1.26.02.003"
+static DEFINE_MUTEX(tw_mutex);
 static TW_Device_Extension *tw_device_extension_list[TW_MAX_SLOT];
 static int tw_device_extension_count = 0;
 static int twe_major = -1;
@@ -900,10 +900,10 @@ static long tw_chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long a
 
 	dprintk(KERN_WARNING "3w-xxxx: tw_chrdev_ioctl()\n");
 
-	lock_kernel();
+	mutex_lock(&tw_mutex);
 	/* Only let one of these through at a time */
 	if (mutex_lock_interruptible(&tw_dev->ioctl_lock)) {
-		unlock_kernel();
+		mutex_unlock(&tw_mutex);
 		return -EINTR;
 	}
 
@@ -1034,7 +1034,7 @@ out2:
 	dma_free_coherent(&tw_dev->tw_pci_dev->dev, data_buffer_length_adjusted+sizeof(TW_New_Ioctl) - 1, cpu_addr, dma_handle);
 out:
 	mutex_unlock(&tw_dev->ioctl_lock);
-	unlock_kernel();
+	mutex_unlock(&tw_mutex);
 	return retval;
 } /* End tw_chrdev_ioctl() */
 
@@ -1044,7 +1044,6 @@ 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);