Re: [PATCH v7 16/22] block: convert to errseq_t based writeback error tracking

[Jeff Layton <jlayton@redhat.com>]

On Tue, 2017-06-20 at 05:35 -0700, Christoph Hellwig wrote:
> >  	error = filemap_write_and_wait_range(filp->f_mapping, start, end);
> >  	if (error)
> > -		return error;
> > +		goto out;
> >  
> >  	/*
> >  	 * There is no need to serialise calls to blkdev_issue_flush with
> > @@ -640,6 +640,10 @@ int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
> >  	if (error == -EOPNOTSUPP)
> >  		error = 0;
> >  
> > +out:
> > +	wberr = filemap_report_wb_err(filp);
> > +	if (!error)
> > +		error = wberr;
> 
> Just curious: what's the reason filemap_write_and_wait_range couldn't
> query for the error using filemap_report_wb_err internally?

In order to query for errors with errseq_t, you need a previously-
sampled point from which to check. When you call
filemap_write_and_wait_range though you don't have a struct file and so
no previously-sampled value.

-- 
Jeff Layton <jlayton@redhat.com>

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>