4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: NeilBrown <[email protected]> commit cfd278c280f997cf2fe4662e0acab0fe465f637b upstream. Various places assume that if nfs4_fl_prepare_ds() turns a non-NULL 'ds', then ds->ds_clp will also be non-NULL. This is not necessasrily true in the case when the process received a fatal signal while nfs4_pnfs_ds_connect is waiting in nfs4_wait_ds_connect(). In that case ->ds_clp may not be set, and the devid may not recently have been marked unavailable. So add a test for ds_clp == NULL and return NULL in that case. Fixes: c23266d532b4 ("NFS4.1 Fix data server connection race") Signed-off-by: NeilBrown <[email protected]> Acked-by: Olga Kornievskaia <[email protected]> Acked-by: Adamson, Andy <[email protected]> Signed-off-by: Trond Myklebust <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/nfs/filelayout/filelayoutdev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/nfs/filelayout/filelayoutdev.c +++ b/fs/nfs/filelayout/filelayoutdev.c @@ -283,7 +283,8 @@ nfs4_fl_prepare_ds(struct pnfs_layout_se s->nfs_client->cl_rpcclient->cl_auth->au_flavor); out_test_devid: - if (filelayout_test_devid_unavailable(devid)) + if (ret->ds_clp == NULL || + filelayout_test_devid_unavailable(devid)) ret = NULL; out: return ret;
