block: autoconvert trivial BKL users to private mutex

The block device drivers have all gained new lock_kernel
calls from a recent pushdown, and some of the drivers
were already using the BKL before.

This turns the BKL into a set of per-driver mutexes.
Still need to check whether this is safe to do.

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>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index fa650dd85b90..e4b56119866e 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -32,7 +32,7 @@
 #include <asm/types.h>
 #include <net/sock.h>
 #include <linux/ctype.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/fs.h>
 #include <linux/file.h>
 #include <linux/proc_fs.h>
@@ -64,6 +64,7 @@ struct after_state_chg_work {
         struct completion *done;
 };
 
+static DEFINE_MUTEX(drbd_main_mutex);
 int drbdd_init(struct drbd_thread *);
 int drbd_worker(struct drbd_thread *);
 int drbd_asender(struct drbd_thread *);
@@ -2536,7 +2537,7 @@ static int drbd_open(struct block_device *bdev, fmode_t mode)
         unsigned long flags;
         int rv = 0;
 
-        lock_kernel();
+        mutex_lock(&drbd_main_mutex);
         spin_lock_irqsave(&mdev->req_lock, flags);
         /* to have a stable mdev->state.role
          * and no race with updating open_cnt */
@@ -2551,7 +2552,7 @@ static int drbd_open(struct block_device *bdev, fmode_t mode)
         if (!rv)
                 mdev->open_cnt++;
         spin_unlock_irqrestore(&mdev->req_lock, flags);
-        unlock_kernel();
+        mutex_unlock(&drbd_main_mutex);
 
         return rv;
 }
@@ -2559,9 +2560,9 @@ static int drbd_open(struct block_device *bdev, fmode_t mode)
 static int drbd_release(struct gendisk *gd, fmode_t mode)
 {
         struct drbd_conf *mdev = gd->private_data;
-        lock_kernel();
+        mutex_lock(&drbd_main_mutex);
         mdev->open_cnt--;
-        unlock_kernel();
+        mutex_unlock(&drbd_main_mutex);
         return 0;
 }