From: Ondrej Mosnacek <omosnace@redhat.com>
Date: Fri, 15 Jan 2021 18:43:56 +0100
Subject: [PATCH] NFSv4.2: fix return value of _nfs4_get_security_label()
Git-commit: 53cb245454df5b13d7063162afd7a785aed6ebf2
Patch-mainline: v5.12
References: git-fixes

An xattr 'get' handler is expected to return the length of the value on
success, yet _nfs4_get_security_label() (and consequently also
nfs4_xattr_get_nfs4_label(), which is used as an xattr handler) returns
just 0 on success.

Fix this by returning label.len instead, which contains the length of
the result.

Fixes: aa9c2669626c ("NFS: Client implementation of Labeled-NFS")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfs/nfs4proc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5352,7 +5352,7 @@ static int _nfs4_get_security_label(stru
 		return ret;
 	if (!(fattr.valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL))
 		return -ENOENT;
-	return 0;
+	return label.len;
 }
 
 static int nfs4_get_security_label(struct inode *inode, void *buf,