From 40cdc7a530c7a075557651a071354bb42b99df08 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 27 Apr 2015 14:50:13 +0200 Subject: [PATCH] nfsd/blocklayout: pretend we can send deviceid notifications Commit df52699e4fcef ("NFSv4.1: Don't cache deviceids that have no notifications") causes the Linux NFS client to stop caching deviceid's unless a server pretends to support deviceid notifications. While this behavior is stupid and the language around this area in rfc5661 is a mess carified by an errata that I submittted, Trond insists on this behavior. Not caching deviceids degrades block layout performance massively as a GETDEVICEINFO is fairly expensive. So add this hack to make the Linux client happy again. Cc: stable@vger.kernel.org Signed-off-by: Christoph Hellwig Signed-off-by: J. Bruce Fields --- fs/nfsd/blocklayout.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c index 03d647bf195d..cdefaa331a07 100644 --- a/fs/nfsd/blocklayout.c +++ b/fs/nfsd/blocklayout.c @@ -181,6 +181,17 @@ nfsd4_block_proc_layoutcommit(struct inode *inode, } const struct nfsd4_layout_ops bl_layout_ops = { + /* + * Pretend that we send notification to the client. This is a blatant + * lie to force recent Linux clients to cache our device IDs. + * We rarely ever change the device ID, so the harm of leaking deviceids + * for a while isn't too bad. Unfortunately RFC5661 is a complete mess + * in this regard, but I filed errata 4119 for this a while ago, and + * hopefully the Linux client will eventually start caching deviceids + * without this again. + */ + .notify_types = + NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE, .proc_getdeviceinfo = nfsd4_block_proc_getdeviceinfo, .encode_getdeviceinfo = nfsd4_block_encode_getdeviceinfo, .proc_layoutget = nfsd4_block_proc_layoutget, -- 2.20.1