isdn: 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: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 4 insertions, 7 deletions

diff --git a/drivers/isdn/hardware/eicon/divamnt.c b/drivers/isdn/hardware/eicon/divamnt.c
index 1e85f74..f1d464f 100644
--- a/drivers/isdn/hardware/eicon/divamnt.c
+++ b/drivers/isdn/hardware/eicon/divamnt.c
@@ -14,7 +14,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/poll.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <asm/uaccess.h>
 
 #include "platform.h"
@@ -22,6 +22,7 @@
 #include "divasync.h"
 #include "debug_if.h"
 
+static DEFINE_MUTEX(maint_mutex);
 static char *main_revision = "$Revision: 1.32.6.10 $";
 
 static int major;
@@ -130,7 +131,7 @@ static int maint_open(struct inode *ino, struct file *filep)
 {
 	int ret;
 
-	lock_kernel();
+	mutex_lock(&maint_mutex);
 	/* only one open is allowed, so we test
 	   it atomically */
 	if (test_and_set_bit(0, &opened))
@@ -139,7 +140,7 @@ static int maint_open(struct inode *ino, struct file *filep)
 		filep->private_data = NULL;
 		ret = nonseekable_open(ino, filep);
 	}
-	unlock_kernel();
+	mutex_unlock(&maint_mutex);
 	return ret;
 }
 
diff --git a/drivers/isdn/hardware/eicon/divasi.c b/drivers/isdn/hardware/eicon/divasi.c
index f577719..42d3b834 100644
--- a/drivers/isdn/hardware/eicon/divasi.c
+++ b/drivers/isdn/hardware/eicon/divasi.c
@@ -18,7 +18,6 @@
 #include <linux/proc_fs.h>
 #include <linux/skbuff.h>
 #include <linux/seq_file.h>
-#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 
 #include "platform.h"
@@ -402,7 +401,6 @@ static unsigned int um_idi_poll(struct file *file, poll_table * wait)
 
 static int um_idi_open(struct inode *inode, struct file *file)
 {
-	cycle_kernel_lock();
 	return (0);
 }
 
diff --git a/drivers/isdn/hardware/eicon/divasmain.c b/drivers/isdn/hardware/eicon/divasmain.c
index fbbcb27..16a874b 100644
--- a/drivers/isdn/hardware/eicon/divasmain.c
+++ b/drivers/isdn/hardware/eicon/divasmain.c
@@ -21,7 +21,6 @@
 #include <linux/list.h>
 #include <linux/poll.h>
 #include <linux/kmod.h>
-#include <linux/smp_lock.h>
 
 #include "platform.h"
 #undef ID_MASK
@@ -581,7 +580,6 @@ xdi_copy_from_user(void *os_handle, void *dst, const void __user *src, int lengt
  */
 static int divas_open(struct inode *inode, struct file *file)
 {
-	cycle_kernel_lock();
 	return (0);
 }