[Toybox] How do I tell cyanogenmod they're wrong?

[Tom Marshall]

In your example below, the permission denied message and subsequent 
failure exit code are the result of EACCES on open(2).  The issue we had 
was when file copying succeeded but the subsequent chown(2) fails.

This can be demonstrated on stock Ubuntu 14.04 as follows:

$ sudo touch foo
$ cp -a foo bar
$ echo $?
0
$ ls -l foo bar
-rw-r--r-- 1 tdm  tdm  0 May 31 18:59 bar
-rw-r--r-- 1 root root 0 May 31 18:59 foo

I can't say that this is correct or even necessarily desirable, but it 
is indeed what coreutils does.

Also note that in your example below, you are using VFAT.  The bug in 
question regards the OnePlus One.  It does not use VFAT (no sdcard), it 
uses ext4 (or possibly f2fs, but mostly ext4).


On 05/29/2016 08:33 PM, Rob Landley wrote:
> Browsing through the cyanogenmod repository. Since they never submitted
> patches to me I'm not going to copy their stuff verbatim (technically
> it could be under a different license), but I'd like to address their
> issues in mainline (modulo the pending stuff), and I get to this:
>
>    http://review.cyanogenmod.org/#/c/131295/
>
> commit b90823e298988ff365cdf8e6d7c17687c3897d55
> Author: Scott Mertz <scott at cyngn.com>
> Date:   Tue Feb 2 14:40:31 2016 -0800
>
>      Don't exit with failure code when cp ownership preservation fails
>      
>      POSIX spec states that it is unspecified whether '-p' prints errors
>      to stderr when preserving ownership fails. GNU coreutils implementation
>      does not write anything to stderr when this fails.  Additionally,
>      '-a' is only specified in GNU coreutils & specifies nothing
>      is to be written to stderr in the case of failure. Switch the
>      implementation to align with GNU coreutils while still satisfying
>      POSIX.
>      
>      OPO-358
>      Change-Id: Ibb7c94fbf553a178b3f88a724ef6f737275a4205
>
> I tried to pull up the OPO-358 thing to see what the original bug
> report was, but it requires a login to view it:
>
>    https://jira.cyngn.com/browse/OPO-358
>
> So I tested it myself, and they're _wrong_:
>
>    dd if=/dev/zero of=vfat.img bs=1M count=1
>    mkfs.vfat vfat.img
>    mkdir vfat
>    sudo /bin/bash
>    toybox mount vfat.img vfat
>
> And then when I go:
>
> # cp -a todo vfat/
> cp: failed to preserve ownership for ‘vfat/todo/attachment.bin.4’: Operation not permitted
> cp: failed to preserve ownership for ‘vfat/todo/attachment-0002.bin’: Operation not permitted
> cp: failed to preserve ownership for ‘vfat/todo/netstat.patch’: Operation not permitted
> cp: failed to preserve ownership for ‘vfat/todo/githash.patch’: Operation not permitted
> cp: failed to preserve ownership for ‘vfat/todo/expr.patch’: Operation not permitted
> ...
>
> The stock ubuntu 14.04 vesion is giving warnings about
> inability to preserve ownership...?
>
> Rob
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