md: remove md_mutex locking.

lock_kernel calls were recently pushed down into open/release
functions.
md doesn't need that protection.
Then the BKL calls were change to md_mutex.  We don't need those
either.
So remove it all.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 0 insertions, 7 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 64f97168cefa..2399168b6315 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -57,8 +57,6 @@
 #define DEBUG 0
 #define dprintk(x...) ((void)(DEBUG && printk(x)))
 
-static DEFINE_MUTEX(md_mutex);
-
 #ifndef MODULE
 static void autostart_arrays(int part);
 #endif
@@ -5887,7 +5885,6 @@ static int md_open(struct block_device *bdev, fmode_t mode)
         mddev_t *mddev = mddev_find(bdev->bd_dev);
         int err;
 
-        mutex_lock(&md_mutex);
         if (mddev->gendisk != bdev->bd_disk) {
                 /* we are racing with mddev_put which is discarding this
                  * bd_disk.
@@ -5896,7 +5893,6 @@ static int md_open(struct block_device *bdev, fmode_t mode)
                 /* Wait until bdev->bd_disk is definitely gone */
                 flush_scheduled_work();
                 /* Then retry the open from the top */
-                mutex_unlock(&md_mutex);
                 return -ERESTARTSYS;
         }
         BUG_ON(mddev != bdev->bd_disk->private_data);
@@ -5910,7 +5906,6 @@ static int md_open(struct block_device *bdev, fmode_t mode)
 
         check_disk_size_change(mddev->gendisk, bdev);
  out:
-        mutex_unlock(&md_mutex);
         return err;
 }
 
@@ -5919,10 +5914,8 @@ static int md_release(struct gendisk *disk, fmode_t mode)
         mddev_t *mddev = disk->private_data;
 
         BUG_ON(!mddev);
-        mutex_lock(&md_mutex);
         atomic_dec(&mddev->openers);
         mddev_put(mddev);
-        mutex_unlock(&md_mutex);
 
         return 0;
 }