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/osst.c b/drivers/scsi/osst.c
index 278b352..54de1d1 100644
--- a/drivers/scsi/osst.c
+++ b/drivers/scsi/osst.c
@@ -51,7 +51,7 @@
#include <linux/moduleparam.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <asm/uaccess.h>
#include <asm/dma.h>
#include <asm/system.h>
@@ -80,6 +80,7 @@
#include "osst_options.h"
#include "osst_detect.h"
+static DEFINE_MUTEX(osst_int_mutex);
static int max_dev = 0;
static int write_threshold_kbs = 0;
static int max_sg_segs = 0;
@@ -4807,9 +4808,9 @@
{
int ret;
- lock_kernel();
+ mutex_lock(&osst_int_mutex);
ret = __os_scsi_tape_open(inode, filp);
- unlock_kernel();
+ mutex_unlock(&osst_int_mutex);
return ret;
}
@@ -4943,9 +4944,9 @@
char * name = tape_name(STp);
void __user * p = (void __user *)arg;
- lock_kernel();
+ mutex_lock(&osst_int_mutex);
if (mutex_lock_interruptible(&STp->lock)) {
- unlock_kernel();
+ mutex_unlock(&osst_int_mutex);
return -ERESTARTSYS;
}
@@ -5260,14 +5261,14 @@
mutex_unlock(&STp->lock);
retval = scsi_ioctl(STp->device, cmd_in, p);
- unlock_kernel();
+ mutex_unlock(&osst_int_mutex);
return retval;
out:
if (SRpnt) osst_release_request(SRpnt);
mutex_unlock(&STp->lock);
- unlock_kernel();
+ mutex_unlock(&osst_int_mutex);
return retval;
}
