Re: [PATCH v7 00/19] xfs: Delayed Ready Attrs

Amir Goldstein
2020-02-23T07:56:00Z

On Sun, Feb 23, 2020 at 4:06 AM Allison Collins
<allison.henderson@oracle.com> wrote:
>
> Hi all,
>
> This set is a subset of a larger series for delayed attributes. Which is
> a subset of an even larger series, parent pointers. Delayed attributes
> allow attribute operations (set and remove) to be logged and committed
> in the same way that other delayed operations do. This allows more
> complex operations (like parent pointers) to be broken up into multiple
> smaller transactions. To do this, the existing attr operations must be
> modified to operate as either a delayed operation or a inline operation
> since older filesystems will not be able to use the new log entries.

High level question, before I dive into the series:

Which other "delayed operations" already exist?
I think delayed operations were added by Darrick to handle the growth of
translation size due to reflink. Right? So I assume the existing delayed
operations deal with block accounting.
When speaking of parent pointers, without having looked into the details yet,
it seem the delayed operations we would want to log are operations that deal
with namespace changes, i.e.: link,unlink,rename.
The information needed to be logged for these ops is minimal.
Why do we need a general infrastructure for delayed attr operations?

Thanks,
Amir.