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>
diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
index f481e73..7e5f238 100644
--- a/drivers/scsi/3w-sas.c
+++ b/drivers/scsi/3w-sas.c
@@ -64,7 +64,6 @@
#include <linux/pci.h>
#include <linux/time.h>
#include <linux/mutex.h>
-#include <linux/smp_lock.h>
#include <linux/slab.h>
#include <asm/io.h>
#include <asm/irq.h>
@@ -77,6 +76,7 @@
/* Globals */
#define TW_DRIVER_VERSION "3.26.02.000"
+static DEFINE_MUTEX(twl_chrdev_mutex);
static TW_Device_Extension *twl_device_extension_list[TW_MAX_SLOT];
static unsigned int twl_device_extension_count;
static int twl_major = -1;
@@ -764,7 +764,7 @@
int retval = -EFAULT;
void __user *argp = (void __user *)arg;
- lock_kernel();
+ mutex_lock(&twl_chrdev_mutex);
/* Only let one of these through at a time */
if (mutex_lock_interruptible(&tw_dev->ioctl_lock)) {
@@ -861,7 +861,7 @@
out2:
mutex_unlock(&tw_dev->ioctl_lock);
out:
- unlock_kernel();
+ mutex_unlock(&twl_chrdev_mutex);
return retval;
} /* End twl_chrdev_ioctl() */
@@ -876,7 +876,6 @@
goto out;
}
- cycle_kernel_lock();
minor_number = iminor(inode);
if (minor_number >= twl_device_extension_count)
goto out;