Re: security.capability xattr missing after btrfs send/receive

[Juan Orti <juan.orti@miceliux.com>]

El dom, 01-02-2015 a las 13:13 +0100, Jan Andres escribió:
> I found that the security.capability xattr gets lost when cloning a
> subvolume via btrfs send | btrfs receive. This is easy to reproduce
> (currently on 3.19.0-rc6, x86_64, with btrfs-progs 3.18.1):
> 
> Have two btrfs file systems, "/fs1" and "/fs2".
> 
> # btrfs sub create /fs1/test
> # touch /fs1/test/foo
> # setcap cap_net_admin+ep /fs1/test/foo
> # getcap /fs1/test/foo
> /fs1/test/foo = cap_net_admin+ep
> # btrfs prop set /fs1/test ro true
> # btrfs send /fs1/test | btrfs receive /fs2
> # getcap /fs2/test/foo
> [reports nothing]
> 
> 
> The cause of the problem seems to be that BTRFS_SEND_C_SET_XATTR comes
> before BTRFS_SEND_C_CHMOD in the send stream, so that the receiving end
> will first correctly restore all the xattrs of the file, and after that,
> perform an lchown() which will cause the kernel to reset the
> file's capabilities.
> 
> I don't know how to fix this correctly (especially in the case of
> incremental sends), so I don't have a patch, but figured it might be
> useful to share what I found.

https://bugzilla.kernel.org/show_bug.cgi?id=68891

-- 
Juan Orti
https://miceliux.com