Hey Trond, Anna, et al.
I'm looking at working on nfs_server_reap_expired_delegations() because the
work to walk that list is order n(n+1)/2 and the list can grow very large
due to some servers doing SEQ4_STATUS_ADMIN_STATE_REVOKED these days. It
can currently grow unlimited by 5k delegation watermark.
First observation is that we don't remove revoked states from the list even
after doing FREE_STATEID, so we're still doing walks across delegation
state we'll never use again. I think we can fix this by plumbing in the
error result from FREE_STATEID.. so that's a potential bit of work.
I'm tempted to just do:
@@ -1342,7 +1346,7 @@ nfs_delegation_test_free_expired(struct inode *inode,
return;
status = ops->test_and_free_expired(server, stateid, cred);
if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID)
- nfs_remove_bad_delegation(inode, stateid);
+ nfs_delegation_mark_returned(inode, stateid);
}
.. but I think that gets us up to not tracking state the server might still
be tracking.
Other approaches might be to walk the list once moving the work to a
temporary list and then operate on that linearly.
Advice, thoughts, or direction welcomed.. I'll probably work on splitting
out nfs41_free_stateid() from test_and_free_expired(), so the delegation
code can know for sure that we're done with that state.
Ben
