From: Jan Olszak <j.olszak@samsung.com>
To: David Howells <dhowells@redhat.com>
Cc: linux-unionfs@vger.kernel.org
Subject: Re: Optional switching off cow in overlayfs
Date: Thu, 18 Jun 2015 16:43:03 +0200 [thread overview]
Message-ID: <5582D8F7.1060700@samsung.com> (raw)
In-Reply-To: <13405.1434634748@warthog.procyon.org.uk>
On 06/18/2015 03:39 PM, David Howells wrote:
> Jan Olszak <j.olszak@samsung.com> wrote:
>
>> I was wondering about a small improvement to overlayfs - optional, per file
>> copy of write.
>>
>> 1. By default overlayfs would work as usual.
>> 2. If a file in 'lower' filesystem has an xattr set
>> (e.g. trusted.overlay.cow=n) the file would not be copied.
>>
>> What do you think?
> Ummm. What's the use case? How do you handle the file being part of multiple
> overlays?
>
> David
>
I wan't to achieve 'files' granularity in overlayfs instead of
'directory' granularity.
It would be useful in Linux containers configuration. Sometimes you
don't have the
power to change the images that are run inside containers and in one
folder you have both:
- files that have to be copied
- files that don't really need to be copied
trusted.overlay.cow==n indicates switching off copying the file to the
upper layer.
So with multiple overlays you would always have only one file from the
lower-most dir.
Jan
next prev parent reply other threads:[~2015-06-18 14:43 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-18 13:25 Optional switching off cow in overlayfs Jan Olszak
2015-06-18 13:39 ` David Howells
2015-06-18 14:43 ` Jan Olszak [this message]
2015-06-22 11:32 ` Miklos Szeredi
2015-06-22 13:45 ` Jan Olszak
2015-06-22 13:53 ` Miklos Szeredi
2015-06-22 14:26 ` Jan Olszak
2015-06-22 14:37 ` Miklos Szeredi
2015-06-22 15:32 ` Jan Olszak
2015-06-23 9:27 ` David Howells
2015-06-23 10:36 ` Jan Olszak
2015-06-23 13:23 ` David Howells
2015-06-23 16:05 ` Jan Olszak
2015-06-23 16:07 ` Jan Olszak
2015-06-24 16:03 ` Jan Olszak
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