mac: 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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@ozlabs.org

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c
index 1c4ee6e..e75e3be 100644
--- a/drivers/macintosh/adb.c
+++ b/drivers/macintosh/adb.c
@@ -24,7 +24,6 @@
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/sched.h>
-#include <linux/smp_lock.h>
 #include <linux/adb.h>
 #include <linux/cuda.h>
 #include <linux/pmu.h>
@@ -55,6 +54,7 @@ extern struct adb_driver adb_iop_driver;
 extern struct adb_driver via_pmu_driver;
 extern struct adb_driver macio_adb_driver;
 
+static DEFINE_MUTEX(adb_mutex);
 static struct adb_driver *adb_driver_list[] = {
 #ifdef CONFIG_ADB_MACII
 	&via_macii_driver,
@@ -647,7 +647,7 @@ static int adb_open(struct inode *inode, struct file *file)
 	struct adbdev_state *state;
 	int ret = 0;
 
-	lock_kernel();
+	mutex_lock(&adb_mutex);
 	if (iminor(inode) > 0 || adb_controller == NULL) {
 		ret = -ENXIO;
 		goto out;
@@ -665,7 +665,7 @@ static int adb_open(struct inode *inode, struct file *file)
 	state->inuse = 1;
 
 out:
-	unlock_kernel();
+	mutex_unlock(&adb_mutex);
 	return ret;
 }
 
@@ -674,7 +674,7 @@ static int adb_release(struct inode *inode, struct file *file)
 	struct adbdev_state *state = file->private_data;
 	unsigned long flags;
 
-	lock_kernel();
+	mutex_lock(&adb_mutex);
 	if (state) {
 		file->private_data = NULL;
 		spin_lock_irqsave(&state->lock, flags);
@@ -687,7 +687,7 @@ static int adb_release(struct inode *inode, struct file *file)
 			spin_unlock_irqrestore(&state->lock, flags);
 		}
 	}
-	unlock_kernel();
+	mutex_unlock(&adb_mutex);
 	return 0;
 }