Merge branch 'master' into for-2.6.35

[safe/jmp/linux-2.6] / fs / block_dev.c

diff --git a/fs/block_dev.c b/fs/block_dev.c
index dd76930..55dcb78 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -406,17 +406,23 @@ static loff_t block_llseek(struct file *file, loff_t offset, int origin)
  
 int blkdev_fsync(struct file *filp, struct dentry *dentry, int datasync)
 {
-       struct block_device *bdev = I_BDEV(filp->f_mapping->host);
+       struct inode *bd_inode = filp->f_mapping->host;
+       struct block_device *bdev = I_BDEV(bd_inode);
        int error;
 
-       error = sync_blockdev(bdev);
-       if (error)
-               return error;
-       
-       error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL,
-                               (BLKDEV_IFL_WAIT));
+       /*
+        * There is no need to serialise calls to blkdev_issue_flush with
+        * i_mutex and doing so causes performance issues with concurrent
+        * O_SYNC writers to a block device.
+        */
+       mutex_unlock(&bd_inode->i_mutex);
+
+       error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL, BLKDEV_IFL_WAIT);
        if (error == -EOPNOTSUPP)
                error = 0;
+
+       mutex_lock(&bd_inode->i_mutex);
+
        return error;
 }
 EXPORT_SYMBOL(blkdev_fsync);