net: 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: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/wan/cosa.c b/drivers/net/wan/cosa.c
index f0bd70f..04c6cd4 100644
--- a/drivers/net/wan/cosa.c
+++ b/drivers/net/wan/cosa.c
@@ -89,7 +89,6 @@
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/device.h>
-#include <linux/smp_lock.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/byteorder.h>
@@ -174,6 +173,7 @@
* Character device major number. 117 was allocated for us.
* The value of 0 means to allocate a first free one.
*/
+static DEFINE_MUTEX(cosa_chardev_mutex);
static int cosa_major = 117;
/*
@@ -944,7 +944,7 @@
int n;
int ret = 0;
- lock_kernel();
+ mutex_lock(&cosa_chardev_mutex);
if ((n=iminor(file->f_path.dentry->d_inode)>>CARD_MINOR_BITS)
>= nr_cards) {
ret = -ENODEV;
@@ -976,7 +976,7 @@
chan->rx_done = chrdev_rx_done;
spin_unlock_irqrestore(&cosa->lock, flags);
out:
- unlock_kernel();
+ mutex_unlock(&cosa_chardev_mutex);
return ret;
}
@@ -1212,10 +1212,10 @@
struct cosa_data *cosa;
long ret;
- lock_kernel();
+ mutex_lock(&cosa_chardev_mutex);
cosa = channel->cosa;
ret = cosa_ioctl_common(cosa, channel, cmd, arg);
- unlock_kernel();
+ mutex_unlock(&cosa_chardev_mutex);
return ret;
}