From: NeilBrown Date: Mon, 19 Dec 2016 00:19:31 +0000 (+1100) Subject: NFSv4.1: nfs4_fl_prepare_ds must be careful about reporting success. X-Git-Tag: C0P2-H0.0--20200415~10605 X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=396b25173370fc1afa3bc91a315d5597c2b10734;p=linux.git NFSv4.1: nfs4_fl_prepare_ds must be careful about reporting success. 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 Acked-by: Olga Kornievskaia Acked-by: Adamson, Andy Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/nfs/filelayout/filelayoutdev.c b/fs/nfs/filelayout/filelayoutdev.c index 4946ef40ba87..85ef38f9765f 100644 --- a/fs/nfs/filelayout/filelayoutdev.c +++ b/fs/nfs/filelayout/filelayoutdev.c @@ -283,7 +283,8 @@ nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx) 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;