The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e3c8dc761ead061da2220ee8f8132f729ac3ddfe Mon Sep 17 00:00:00 2001
From: Trond Myklebust trond.myklebust@hammerspace.com Date: Mon, 29 Jul 2019 18:25:00 +0100 Subject: [PATCH] NFSv4: Check the return value of update_open_stateid()
Ensure that we always check the return value of update_open_stateid() so that we can retry if the update of local state failed. This fixes infinite looping on state recovery.
Fixes: e23008ec81ef3 ("NFSv4 reduce attribute requests for open reclaim") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Cc: stable@vger.kernel.org # v3.7+
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index c9e14ce0b7b2..3e0b93f2b61a 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -1915,8 +1915,9 @@ _nfs4_opendata_reclaim_to_nfs4_state(struct nfs4_opendata *data) if (data->o_res.delegation_type != 0) nfs4_opendata_check_deleg(data, state); update: - update_open_stateid(state, &data->o_res.stateid, NULL, - data->o_arg.fmode); + if (!update_open_stateid(state, &data->o_res.stateid, + NULL, data->o_arg.fmode)) + return ERR_PTR(-EAGAIN); refcount_inc(&state->count);
return state; @@ -1981,8 +1982,11 @@ _nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data)
if (data->o_res.delegation_type != 0) nfs4_opendata_check_deleg(data, state); - update_open_stateid(state, &data->o_res.stateid, NULL, - data->o_arg.fmode); + if (!update_open_stateid(state, &data->o_res.stateid, + NULL, data->o_arg.fmode)) { + nfs4_put_open_state(state); + state = ERR_PTR(-EAGAIN); + } out: nfs_release_seqid(data->o_arg.seqid); return state;