[PATCH v2 0/2][Xenial SRU] Fix docker permission issues with the overlay2 storage driver

[Stefan Bader]

On 30.01.2017 23:06, Seth Forshee wrote:
> BugLink: http://bugs.launchpad.net/bugs/1659417
> 
> Under some conditions docker users who use the overlay2 storage driver
> on xenial are seeing erroneous "permission denied" errors. This is
> caused by a bug in overlayfs which was fixed by two commits in 4.6. The
> following are backports of those patches to xenial.
> 
> Changes in v2: Fix locking

The set is dangerously confusing. The first patch which adds the helper has
little in common with what is (or better was since it got reverted) upstream and
the second change seems to have been re-done (probably with more dependencies in
c1b2cc1a765aff4df7b22abe6b66014236f73eba.

I wonder whether it would not be better to try backporting the final state of
this (if that does not end up being a huge mess) or at least combine the current
two into a SAUCE patch. The locking I would then keep in the overlayfs code and
the helper is more or less just exporting the __lookup_hash function. I guess
most of the comment is true for that as well. Except the one line about i_mutex.
But the way the upstream change implemented it makes it hard to compare.

-Stefan
> 
> Thanks,
> Seth
> 
> Miklos Szeredi (2):
>   vfs: add lookup_hash() helper
>   ovl: ignore permissions on underlying lookup
> 
>  fs/namei.c            | 26 ++++++++++++++++++++++++++
>  fs/overlayfs/super.c  |  4 +---
>  include/linux/namei.h |  2 ++
>  3 files changed, 29 insertions(+), 3 deletions(-)
> 
> 


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