lkml.org 
[lkml]   [2014]   [Feb]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 00/13] cross rename v4
From
On Thu, Feb 13, 2014 at 5:42 PM, David Howells <dhowells@redhat.com> wrote:
> Miklos Szeredi <miklos@szeredi.hu> wrote:
>
>> Regarding whiteouts, I raised a couple of questions that nobody answered
>> yet, so let me ask again.
>>
>> - If a filesystem containing whiteouts (fallthroughs, etc...) is mounted as
>> not part of a union, how are these special entities represented to
>> userspace?
>
> I would suggest that whiteouts appear as otherwise negative dentries and that
> they don't appear in getdents().

I'd argue that this is an administration nightmare. E.g. what if the
a backup needs to be made of the rw layer?

Will rmdir work normally in a directory containing whiteouts? Will
the VFS take care of that, just like if it was part of a union? Or
will it fail with ENOTEMPTY despite *appearing* empty?

And zillion other problems related to the fact that things happen to a
filesystem even when they do not appear to happen ("mv foo bar; mv bar
foo" has side effects).

Thanks,
Miklos


\
 
 \ /
  Last update: 2014-02-13 19:01    [W:0.069 / U:2.196 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site