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/megaraid.c b/drivers/scsi/megaraid.c
index 0b6e322..4d0cf5c 100644
--- a/drivers/scsi/megaraid.c
+++ b/drivers/scsi/megaraid.c
@@ -46,7 +46,7 @@
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/slab.h>
#include <scsi/scsicam.h>
@@ -62,6 +62,7 @@
MODULE_LICENSE ("GPL");
MODULE_VERSION(MEGARAID_MODULE_VERSION);
+static DEFINE_MUTEX(megadev_mutex);
static unsigned int max_cmd_per_lun = DEF_CMD_PER_LUN;
module_param(max_cmd_per_lun, uint, 0);
MODULE_PARM_DESC(max_cmd_per_lun, "Maximum number of commands which can be issued to a single LUN (default=DEF_CMD_PER_LUN=63)");
@@ -3282,7 +3283,6 @@
static int
megadev_open (struct inode *inode, struct file *filep)
{
- cycle_kernel_lock();
/*
* Only allow superuser to access private ioctl interface
*/
@@ -3701,9 +3701,9 @@
{
int ret;
- lock_kernel();
+ mutex_lock(&megadev_mutex);
ret = megadev_ioctl(filep, cmd, arg);
- unlock_kernel();
+ mutex_unlock(&megadev_mutex);
return ret;
}