From: Olga Kornievskaia <kolga@netapp.com>
Date: Thu, 9 Dec 2021 14:53:29 -0500
Subject: [PATCH] NFSv4 remove zero number of fs_locations entries error check
Git-commit: 90e12a3191040bd3854d3e236c35921e4e92a044
Patch-mainline: v5.17
References: git-fixes

Remove the check for the zero length fs_locations reply in the
xdr decoding, and instead check for that in the migration code.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfs/nfs4state.c |    3 +++
 fs/nfs/nfs4xdr.c   |    2 --
 2 files changed, 3 insertions(+), 2 deletions(-)

--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -2122,6 +2122,9 @@ static int nfs4_try_migration(struct nfs
 	}
 
 	result = -NFS4ERR_NXIO;
+	if (!locations->nlocations)
+		goto out;
+
 	if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
 		dprintk("<-- %s: No fs_locations data, migration skipped\n",
 			__func__);
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -3696,8 +3696,6 @@ static int decode_attr_fs_locations(stru
 	if (unlikely(!p))
 		goto out_eio;
 	n = be32_to_cpup(p);
-	if (n <= 0)
-		goto out_eio;
 	for (res->nlocations = 0; res->nlocations < n; res->nlocations++) {
 		u32 m;
 		struct nfs4_fs_location *loc;