From 39f897fdbd46873defc8501102124f862e8f4d80 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 29 Jun 2015 14:28:54 +1000 Subject: [PATCH] NFSv4: When returning a delegation, don't reclaim an incompatible open mode. It is possible to have an active open with one mode, and a delegation for the same file with a different mode. In particular, a WR_ONLY open and an RD_ONLY delegation. This happens if a WR_ONLY open is followed by a RD_ONLY open which provides a delegation, but is then close. When returning the delegation, we currently try to claim opens for every open type (n_rdwr, n_rdonly, n_wronly). As there is no harm in claiming an open for a mode that we already have, this is often simplest. However if the delegation only provides a subset of the modes that we currently have open, this will produce an error from the server. So when claiming open modes prior to returning a delegation, skip the open request if the mode is not covered by the delegation - the open_stateid must already cover that mode, so there is nothing to do. Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 8eab42407d39..605c203de556 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -1547,6 +1547,13 @@ static int nfs4_open_recover_helper(struct nfs4_opendata *opendata, fmode_t fmod struct nfs4_state *newstate; int ret; + if ((opendata->o_arg.claim == NFS4_OPEN_CLAIM_DELEGATE_CUR || + opendata->o_arg.claim == NFS4_OPEN_CLAIM_DELEG_CUR_FH) && + (opendata->o_arg.u.delegation_type & fmode) != fmode) + /* This mode can't have been delegated, so we must have + * a valid open_stateid to cover it - not need to reclaim. + */ + return 0; opendata->o_arg.open_flags = 0; opendata->o_arg.fmode = fmode; opendata->o_arg.share_access = nfs4_map_atomic_open_share(