On Tue, 2016-11-15 at 21:31 +0100, Jiri Pirko wrote:
> Tue, Nov 15, 2016 at 09:29:09PM CET, alexander.h.du...@intel.com wrote:
> >
> > On Tue, 2016-11-15 at 20:51 +0100, Jiri Pirko wrote:
> > >
> > > Tue, Nov 15, 2016 at 11:46:06AM CET, alexander.h.du...@intel.com wrote:
> > > >
> > > >
> > > > The patch that removed the FIB offload infrastructure was a bit too
> > > > aggressive and also removed code needed to clean up us splitting the
> > > > table
> > > > if additional rules were added. Specifically the function
> > > > fib_trie_flush_external was called at the end of a new rule being added
> > > > to
> > > > flush the foreign trie entries from the main trie.
> > > >
> > > > I updated the code so that we only call fib_trie_flush_external on the
> > > > main
> > > > table so that we flush the entries for local from main. This way we
> > > > don't
> > > > call it for every rule change which is what was happening previously.
> > >
> > > Well, the function was introduced by:
> > >
> > > commit 104616e74e0b464d449fdd2ee2f547d2fad71610
> > > Author: Scott Feldman <sfel...@gmail.com>
> > > Date: Thu Mar 5 21:21:16 2015 -0800
> > >
> > > switchdev: don't support custom ip rules, for now
> > >
> > > Keep switchdev FIB offload model simple for now and don't allow
> > > custom ip
> > > rules.
> > >
> > > Why this was not needed before? What changed in between:
> > > 104616e74e0b464d449fdd2ee2f547d2fad71610 ("switchdev: don't support
> > > custom ip rules, for now")
> > > and
> > > 347e3b28c1ba2 ("switchdev: remove FIB offload infrastructure")
> >
> > We collapsed the two tables into one in commit 0ddcf43d5d4a ("ipv4: FIB
> > Local/MAIN table collapse") which was submitted the next day. Scott
> > and I were working on things at the same time and the
> > fib_table_flush_external function was something we had worked out that
> > would allow him to take care of his use case and me to take care of
> > cleaning up the tables after unmerging.
>
> Okay. But please name the fuction differently, as it does not flush
> external. Thanks!
You and I have different meanings for "external".
In my case I am flushing entries that belong to a foreign "external"
table from the table specified. So by "external" I am referring to
entries that don't actually live in main, but actually reside in local.
If you take a look at fib_table_flush that gets rid of all entries,
fib_table_flush_external simply clears the foreign ones.
Also I'd rather maintain naming since it makes it easier if we need to
backport fixes.
Finally, the flag RTNH_F_EXTERNAL was renamed over a year ago in commit
36583eb54d46c ("rename RTNH_F_EXTERNAL to RTNH_F_OFFLOAD") so there
isn't too much likelihood of this being confused for something that
handles offloaded entries. If you take a look in net/ipv4/* after your
patch there isn't actually anything that references the word external
so the likelihood for any confusion is extremely low.
- Alex
