From 1181e8687a8d075841b1e8876ec6cc503219e207 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 12 Jul 2018 14:19:03 -0400 Subject: [PATCH] NFSv4.1: Fix a potential layoutget/layoutrecall deadlock [ Upstream commit bd3d16a887b0c19a2a20d35ffed499e3a3637feb ] If the client is sending a layoutget, but the server issues a callback to recall what it thinks may be an outstanding layout, then we may find an uninitialised layout attached to the inode due to the layoutget. In that case, it is appropriate to return NFS4ERR_NOMATCHING_LAYOUT rather than NFS4ERR_DELAY, as the latter can end up deadlocking. Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/nfs/callback_proc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c index 2c3f398995f6..b8d55da2f04d 100644 --- a/fs/nfs/callback_proc.c +++ b/fs/nfs/callback_proc.c @@ -213,9 +213,9 @@ static u32 pnfs_check_callback_stateid(struct pnfs_layout_hdr *lo, { u32 oldseq, newseq; - /* Is the stateid still not initialised? */ + /* Is the stateid not initialised? */ if (!pnfs_layout_is_valid(lo)) - return NFS4ERR_DELAY; + return NFS4ERR_NOMATCHING_LAYOUT; /* Mismatched stateid? */ if (!nfs4_stateid_match_other(&lo->plh_stateid, new)) -- 2.50.1