From: Jens Axboe <jens.axboe@oracle.com>
Date: Thu, 29 Apr 2010 07:36:24 +0000 (+0200)
Subject: Merge branch 'master' into for-2.6.35
X-Git-Tag: v2.6.35-rc1~442^2~60
X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=7407cf355fdf5500430be966dbbde84a27293bad

Merge branch 'master' into for-2.6.35

Conflicts:
	fs/block_dev.c

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

7407cf355fdf5500430be966dbbde84a27293bad
diff --cc fs/block_dev.c
index dd76930,6dcee88..55dcb78
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@@ -406,17 -406,23 +406,23 @@@ static loff_t block_llseek(struct file 
   
  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, NULL);
++	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);