Re: [PATCH v5 2/4] ovl: allocate anonymous devs for lowerdirs

[Amir Goldstein <amir73il@gmail.com>]

On Wed, Nov 1, 2017 at 3:17 PM, Chandan Rajendra
<chandan@linux.vnet.ibm.com> wrote:
> On Wednesday, November 1, 2017 4:31:00 AM IST Amir Goldstein wrote:
...
>>
>> Pushed the requested changes to branch:
>> https://github.com/amir73il/linux/commits/ovl-nonsamefs-v6
>>
>> Currently same tip as overlayfs-devel.
>>
>
> Amir, The changes look fine to me. Thanks for addressing the review comments.
>

No problem, but just found another problem in testing -
When we iterate pure lower or upper dir type entries
we do not adjust their d_ino to overlay ino, which is differnt
than real ino for non-samefs dirs.
example ((mnt/b is pure upper):
=====================================
# ls -li /mnt/
total 0
16237 drwxr-xr-x  2 root root   40 Nov  1 13:12 b

# find /mnt -inum 16237
/mnt/b

# ../xfstests/src/t_dir_type /mnt/b 16237
. d

# ../xfstests/src/t_dir_type /mnt/b 16237

<nothing>
=====================================

This problem does not affect 'find -inum' because 'find' always
does stat(2) for directories to check st_ino and more.

But the problem does affect decoding of NFS file handles
because the default get_name() implementation relies on
d_ino lookup to match child name with disconnected child dentry.

I will fix it up.

Chandan,

When you have time, please send a fix to xfstests 038 and 041 to test
this missed use case and please send a nonsamefs test variant of 017.

Thanks,
Amir.