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From: Amir Goldstein <amir73il@gmail.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: overlayfs <linux-unionfs@vger.kernel.org>,
	Miklos Szeredi <miklos@szeredi.hu>
Subject: Re: [PATCH v9 14/15] ovl: Fix encryption/compression status of a metacopy only file
Date: Thu, 18 Jan 2018 16:32:01 +0200	[thread overview]
Message-ID: <CAOQ4uxiLMF6BmzF9hzX6LD7eeX_=-6w1aWir5-d61bj3ojpXxQ@mail.gmail.com> (raw)
In-Reply-To: <20180118142453.GA5769@redhat.com>

On Thu, Jan 18, 2018 at 4:24 PM, Vivek Goyal <vgoyal@redhat.com> wrote:
> On Wed, Nov 29, 2017 at 10:54:47AM -0500, Vivek Goyal wrote:
>> If file is metacopy only, it is possible that lower is encrypted while
>> other is not. In that case, report file as encrypted (despite the fact
>> that only data is encrypted while metadata is not).
>>
>> Similarly if lower is compressed, report that in stat for a metacopy
>> only file.
>>
>
> Hi Amir,
>
> Thinking more about this patch. Taking union of lower and upper attributes
> (encryption and compressed) does not feel right.
>
> Right now if lower is compressed and upper is not (metacopy), then we will
> report file as compressed. But if lower is not compressed while upper is,
> still we will report file as compressed. So there is an anomaly here.
>
> I think, compression and encryption primarily represent the data state.
> So always report the state from inode which has file data (lower). And
> don't take union with upper metacopy only inode. Because state in
> upper inode does not matter till data is copied up.
>
> This will also simplify my implementation when supporting metacopy in
> middle layer. That way I don't have to do getattr() on all intermediate
> metacopy inodes in the chain and take a union. Instead I can go to lowest
> most data inode and take encryption and compression attributes from there.
>
> I am not sure why did we decide to take union of lower and upper attrs.
> Right now it does not seem to make sense to me.
>

Now I am not sure either. I suspect that userspace may need the ability to
know if a file is encrypted, but I can't say for sure.
If you want to know better ask the developers that work of fs/crypto.

I don't mind if you leave this patch out.

Cheers,
Amir.

  reply	other threads:[~2018-01-18 14:32 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-29 15:54 [PATCH v9 00/15] overlayfs: Delayed copy up of data Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 01/15] ovl: Do not look for OVL_XATTR_NLINK if index is not there Vivek Goyal
2017-11-29 17:04   ` Amir Goldstein
2017-11-29 15:54 ` [PATCH v9 02/15] ovl: disable redirect_dir and index when no xattr support Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 03/15] ovl: ovl_check_setxattr() get rid of redundant -EOPNOTSUPP check Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 04/15] ovl: Create origin xattr on copy up for all files Vivek Goyal
2018-01-08 10:16   ` Miklos Szeredi
2018-01-08 11:18     ` Amir Goldstein
2018-01-08 15:58       ` Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 05/15] ovl: Provide a mount option metacopy=on/off for metadata copyup Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 06/15] ovl: During copy up, first copy up metadata and then data Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 07/15] ovl: Move the copy up helpers to copy_up.c Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 08/15] ovl: Copy up only metadata during copy up where it makes sense Vivek Goyal
2018-01-08 10:35   ` Miklos Szeredi
2018-01-08 17:03     ` Vivek Goyal
2018-01-09 10:49       ` Miklos Szeredi
2018-01-09 13:26         ` Vivek Goyal
2018-01-09 13:33           ` Amir Goldstein
2018-01-09 20:34             ` Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 09/15] ovl: Add helper ovl_already_copied_up() Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 10/15] ovl: A new xattr OVL_XATTR_METACOPY for file on upper Vivek Goyal
2018-01-08 15:50   ` Miklos Szeredi
2018-01-08 16:17     ` Vivek Goyal
2018-01-08 16:21       ` Miklos Szeredi
2018-01-08 16:25         ` Miklos Szeredi
2017-11-29 15:54 ` [PATCH v9 11/15] ovl: Fix ovl_getattr() to get number of blocks from lower Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 12/15] ovl: Set OVL_UPPERDATA flag during ovl_lookup() Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 13/15] ovl: Do not expose metacopy only upper dentry from d_real() Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 14/15] ovl: Fix encryption/compression status of a metacopy only file Vivek Goyal
2018-01-18 14:24   ` Vivek Goyal
2018-01-18 14:32     ` Amir Goldstein [this message]
2018-01-18 14:36       ` Vivek Goyal
2017-11-29 15:54 ` [PATCH v9 15/15] ovl: Enable metadata only feature Vivek Goyal
2018-01-06  7:38 ` [PATCH v9 00/15] overlayfs: Delayed copy up of data Amir Goldstein
2018-01-08 14:13   ` Vivek Goyal
2018-01-08 14:42     ` Amir Goldstein
2018-01-08 15:44       ` Vivek Goyal
2018-01-10 14:56       ` Vivek Goyal
2018-01-10 15:08         ` Miklos Szeredi
2018-01-10 15:23           ` Vivek Goyal
2018-01-10 15:10         ` Amir Goldstein
2018-01-10 15:27           ` Vivek Goyal
2018-01-10 15:38             ` Miklos Szeredi
2018-01-10 15:47               ` Vivek Goyal
2018-01-10 15:54                 ` Amir Goldstein
2018-01-10 16:03                   ` Miklos Szeredi
2018-01-10 16:30                     ` Vivek Goyal
2018-01-10 17:05                       ` Amir Goldstein

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