From 7919d0a27f1e7cb324e023776aa1cbff00f1ee7b Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 16 Sep 2016 16:28:25 -0400 Subject: nfsd: add a LRU list for blocked locks It's possible for a client to call in on a lock that is blocked for a long time, but discontinue polling for it. A malicious client could even set a lock on a file, and then spam the server with failing lock requests from different lockowners that pile up in a DoS attack. Add the blocked lock structures to a per-net namespace LRU when hashing them, and timestamp them. If the lock request is not revisited after a lease period, we'll drop it under the assumption that the client is no longer interested. This also gives us a mechanism to clean up these objects at server shutdown time as well. Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields --- fs/nfsd/netns.h | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/nfsd/netns.h') diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index 5fbf3bbd00d0..b10d557f9c9e 100644 --- a/fs/nfsd/netns.h +++ b/fs/nfsd/netns.h @@ -84,6 +84,7 @@ struct nfsd_net { struct list_head client_lru; struct list_head close_lru; struct list_head del_recall_lru; + struct list_head blocked_locks_lru; struct delayed_work laundromat_work; -- cgit v1.2.3-70-g09d2