1 files changed, 17 insertions, 10 deletions

diff --git a/fs/block_dev.c b/fs/block_dev.c
index cdfb625824e2..7eeb0635338b 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -127,7 +127,7 @@ int set_blocksize(struct block_device *bdev, int size)
                 return -EINVAL;
 
         /* Prevent starting I/O or mapping the device */
-        down_write(&bdev->bd_block_size_semaphore);
+        percpu_down_write(&bdev->bd_block_size_semaphore);
 
         /* Check that the block device is not memory mapped */
         mapping = bdev->bd_inode->i_mapping;
@@ -135,7 +135,7 @@ int set_blocksize(struct block_device *bdev, int size)
         if (!prio_tree_empty(&mapping->i_mmap) ||
             !list_empty(&mapping->i_mmap_nonlinear)) {
                 mutex_unlock(&mapping->i_mmap_mutex);
-                up_write(&bdev->bd_block_size_semaphore);
+                percpu_up_write(&bdev->bd_block_size_semaphore);
                 return -EBUSY;
         }
         mutex_unlock(&mapping->i_mmap_mutex);
@@ -148,7 +148,7 @@ int set_blocksize(struct block_device *bdev, int size)
                 kill_bdev(bdev);
         }
 
-        up_write(&bdev->bd_block_size_semaphore);
+        percpu_up_write(&bdev->bd_block_size_semaphore);
 
         return 0;
 }
@@ -460,6 +460,12 @@ static struct inode *bdev_alloc_inode(struct super_block *sb)
         struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL);
         if (!ei)
                 return NULL;
+
+        if (unlikely(percpu_init_rwsem(&ei->bdev.bd_block_size_semaphore))) {
+                kmem_cache_free(bdev_cachep, ei);
+                return NULL;
+        }
+
         return &ei->vfs_inode;
 }
 
@@ -468,6 +474,8 @@ static void bdev_i_callback(struct rcu_head *head)
         struct inode *inode = container_of(head, struct inode, i_rcu);
         struct bdev_inode *bdi = BDEV_I(inode);
 
+        percpu_free_rwsem(&bdi->bdev.bd_block_size_semaphore);
+
         kmem_cache_free(bdev_cachep, bdi);
 }
 
@@ -491,7 +499,6 @@ static void init_once(void *foo)
         inode_init_once(&ei->vfs_inode);
         /* Initialize mutex for freeze. */
         mutex_init(&bdev->bd_fsfreeze_mutex);
-        init_rwsem(&bdev->bd_block_size_semaphore);
 }
 
 static inline void __bd_forget(struct inode *inode)
@@ -1593,11 +1600,11 @@ ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov,
         ssize_t ret;
         struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host);
 
-        down_read(&bdev->bd_block_size_semaphore);
+        percpu_down_read(&bdev->bd_block_size_semaphore);
 
         ret = generic_file_aio_read(iocb, iov, nr_segs, pos);
 
-        up_read(&bdev->bd_block_size_semaphore);
+        percpu_up_read(&bdev->bd_block_size_semaphore);
 
         return ret;
 }
@@ -1622,7 +1629,7 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 
         blk_start_plug(&plug);
 
-        down_read(&bdev->bd_block_size_semaphore);
+        percpu_down_read(&bdev->bd_block_size_semaphore);
 
         ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
         if (ret > 0 || ret == -EIOCBQUEUED) {
@@ -1633,7 +1640,7 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
                         ret = err;
         }
 
-        up_read(&bdev->bd_block_size_semaphore);
+        percpu_up_read(&bdev->bd_block_size_semaphore);
 
         blk_finish_plug(&plug);
 
@@ -1646,11 +1653,11 @@ int blkdev_mmap(struct file *file, struct vm_area_struct *vma)
         int ret;
         struct block_device *bdev = I_BDEV(file->f_mapping->host);
 
-        down_read(&bdev->bd_block_size_semaphore);
+        percpu_down_read(&bdev->bd_block_size_semaphore);
 
         ret = generic_file_mmap(file, vma);
 
-        up_read(&bdev->bd_block_size_semaphore);
+        percpu_up_read(&bdev->bd_block_size_semaphore);
 
         return ret;
 }