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/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index cad6f9a..6e23336 100644
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -38,7 +38,7 @@
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/syscalls.h>
#include <linux/delay.h>
@@ -76,6 +76,7 @@
MODULE_LICENSE("GPL");
MODULE_VERSION(AAC_DRIVER_FULL_VERSION);
+static DEFINE_MUTEX(aac_mutex);
static LIST_HEAD(aac_devices);
static int aac_cfg_major = -1;
char aac_driver_version[] = AAC_DRIVER_FULL_VERSION;
@@ -678,7 +679,7 @@
unsigned minor_number = iminor(inode);
int err = -ENODEV;
- lock_kernel(); /* BKL pushdown: nothing else protects this list */
+ mutex_lock(&aac_mutex); /* BKL pushdown: nothing else protects this list */
list_for_each_entry(aac, &aac_devices, entry) {
if (aac->id == minor_number) {
file->private_data = aac;
@@ -686,7 +687,7 @@
break;
}
}
- unlock_kernel();
+ mutex_unlock(&aac_mutex);
return err;
}
@@ -711,9 +712,9 @@
int ret;
if (!capable(CAP_SYS_RAWIO))
return -EPERM;
- lock_kernel();
+ mutex_lock(&aac_mutex);
ret = aac_do_ioctl(file->private_data, cmd, (void __user *)arg);
- unlock_kernel();
+ mutex_unlock(&aac_mutex);
return ret;
}
@@ -722,7 +723,7 @@
static long aac_compat_do_ioctl(struct aac_dev *dev, unsigned cmd, unsigned long arg)
{
long ret;
- lock_kernel();
+ mutex_lock(&aac_mutex);
switch (cmd) {
case FSACTL_MINIPORT_REV_CHECK:
case FSACTL_SENDFIB:
@@ -756,7 +757,7 @@
ret = -ENOIOCTLCMD;
break;
}
- unlock_kernel();
+ mutex_unlock(&aac_mutex);
return ret;
}