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);