Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/nfs/nfs4idmap.c b/fs/nfs/nfs4idmap.c
index 3f23b68..1e72963 100644
--- a/fs/nfs/nfs4idmap.c
+++ b/fs/nfs/nfs4idmap.c
@@ -44,6 +44,7 @@
 #include <linux/keyctl.h>
 #include <linux/key-type.h>
 #include <keys/user-type.h>
+#include <keys/request_key_auth-type.h>
 #include <linux/module.h>
 
 #include "internal.h"
@@ -59,7 +60,7 @@
 struct idmap_legacy_upcalldata {
 	struct rpc_pipe_msg pipe_msg;
 	struct idmap_msg idmap_msg;
-	struct key_construction	*key_cons;
+	struct key	*authkey;
 	struct idmap *idmap;
 };
 
@@ -68,8 +69,16 @@
 	struct rpc_pipe		*idmap_pipe;
 	struct idmap_legacy_upcalldata *idmap_upcall_data;
 	struct mutex		idmap_mutex;
+	const struct cred	*cred;
 };
 
+static struct user_namespace *idmap_userns(const struct idmap *idmap)
+{
+	if (idmap && idmap->cred)
+		return idmap->cred->user_ns;
+	return &init_user_ns;
+}
+
 /**
  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
  * @fattr: fully initialised struct nfs_fattr
@@ -270,18 +279,19 @@
 					 const char *type, struct idmap *idmap)
 {
 	char *desc;
-	struct key *rkey;
+	struct key *rkey = ERR_PTR(-EAGAIN);
 	ssize_t ret;
 
 	ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
 	if (ret < 0)
 		return ERR_PTR(ret);
 
-	rkey = request_key(&key_type_id_resolver, desc, "");
+	if (!idmap->cred || idmap->cred->user_ns == &init_user_ns)
+		rkey = request_key(&key_type_id_resolver, desc, "");
 	if (IS_ERR(rkey)) {
 		mutex_lock(&idmap->idmap_mutex);
 		rkey = request_key_with_auxdata(&key_type_id_resolver_legacy,
-						desc, "", 0, idmap);
+						desc, NULL, "", 0, idmap);
 		mutex_unlock(&idmap->idmap_mutex);
 	}
 	if (!IS_ERR(rkey))
@@ -384,7 +394,7 @@
 	{ Opt_find_err, NULL }
 };
 
-static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
+static int nfs_idmap_legacy_upcall(struct key *, void *);
 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 				   size_t);
 static void idmap_release_pipe(struct inode *);
@@ -451,6 +461,9 @@
 	if (idmap == NULL)
 		return -ENOMEM;
 
+	mutex_init(&idmap->idmap_mutex);
+	idmap->cred = get_cred(clp->cl_rpcclient->cl_cred);
+
 	rpc_init_pipe_dir_object(&idmap->idmap_pdo,
 			&nfs_idmap_pipe_dir_object_ops,
 			idmap);
@@ -461,7 +474,6 @@
 		goto err;
 	}
 	idmap->idmap_pipe = pipe;
-	mutex_init(&idmap->idmap_mutex);
 
 	error = rpc_add_pipe_dir_object(clp->cl_net,
 			&clp->cl_rpcclient->cl_pipedir_objects,
@@ -474,6 +486,7 @@
 err_destroy_pipe:
 	rpc_destroy_pipe_data(idmap->idmap_pipe);
 err:
+	put_cred(idmap->cred);
 	kfree(idmap);
 	return error;
 }
@@ -490,6 +503,7 @@
 			&clp->cl_rpcclient->cl_pipedir_objects,
 			&idmap->idmap_pdo);
 	rpc_destroy_pipe_data(idmap->idmap_pipe);
+	put_cred(idmap->cred);
 	kfree(idmap);
 }
 
@@ -549,11 +563,12 @@
 static void
 nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
 {
-	struct key_construction *cons = idmap->idmap_upcall_data->key_cons;
+	struct key *authkey = idmap->idmap_upcall_data->authkey;
 
 	kfree(idmap->idmap_upcall_data);
 	idmap->idmap_upcall_data = NULL;
-	complete_request_key(cons, ret);
+	complete_request_key(authkey, ret);
+	key_put(authkey);
 }
 
 static void
@@ -563,15 +578,14 @@
 		nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 }
 
-static int nfs_idmap_legacy_upcall(struct key_construction *cons,
-				   const char *op,
-				   void *aux)
+static int nfs_idmap_legacy_upcall(struct key *authkey, void *aux)
 {
 	struct idmap_legacy_upcalldata *data;
+	struct request_key_auth *rka = get_request_key_auth(authkey);
 	struct rpc_pipe_msg *msg;
 	struct idmap_msg *im;
 	struct idmap *idmap = (struct idmap *)aux;
-	struct key *key = cons->key;
+	struct key *key = rka->target_key;
 	int ret = -ENOKEY;
 
 	if (!aux)
@@ -586,7 +600,7 @@
 	msg = &data->pipe_msg;
 	im = &data->idmap_msg;
 	data->idmap = idmap;
-	data->key_cons = cons;
+	data->authkey = key_get(authkey);
 
 	ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
 	if (ret < 0)
@@ -604,7 +618,7 @@
 out2:
 	kfree(data);
 out1:
-	complete_request_key(cons, ret);
+	complete_request_key(authkey, ret);
 	return ret;
 }
 
@@ -651,9 +665,10 @@
 static ssize_t
 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 {
+	struct request_key_auth *rka;
 	struct rpc_inode *rpci = RPC_I(file_inode(filp));
 	struct idmap *idmap = (struct idmap *)rpci->private;
-	struct key_construction *cons;
+	struct key *authkey;
 	struct idmap_msg im;
 	size_t namelen_in;
 	int ret = -ENOKEY;
@@ -665,7 +680,8 @@
 	if (idmap->idmap_upcall_data == NULL)
 		goto out_noupcall;
 
-	cons = idmap->idmap_upcall_data->key_cons;
+	authkey = idmap->idmap_upcall_data->authkey;
+	rka = get_request_key_auth(authkey);
 
 	if (mlen != sizeof(im)) {
 		ret = -ENOSPC;
@@ -690,9 +706,9 @@
 
 	ret = nfs_idmap_read_and_verify_message(&im,
 			&idmap->idmap_upcall_data->idmap_msg,
-			cons->key, cons->authkey);
+			rka->target_key, authkey);
 	if (ret >= 0) {
-		key_set_timeout(cons->key, nfs_idmap_cache_timeout);
+		key_set_timeout(rka->target_key, nfs_idmap_cache_timeout);
 		ret = mlen;
 	}
 
@@ -732,7 +748,7 @@
 	if (!nfs_map_string_to_numeric(name, namelen, &id))
 		ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap);
 	if (ret == 0) {
-		*uid = make_kuid(&init_user_ns, id);
+		*uid = make_kuid(idmap_userns(idmap), id);
 		if (!uid_valid(*uid))
 			ret = -ERANGE;
 	}
@@ -749,7 +765,7 @@
 	if (!nfs_map_string_to_numeric(name, namelen, &id))
 		ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap);
 	if (ret == 0) {
-		*gid = make_kgid(&init_user_ns, id);
+		*gid = make_kgid(idmap_userns(idmap), id);
 		if (!gid_valid(*gid))
 			ret = -ERANGE;
 	}
@@ -763,7 +779,7 @@
 	int ret = -EINVAL;
 	__u32 id;
 
-	id = from_kuid(&init_user_ns, uid);
+	id = from_kuid_munged(idmap_userns(idmap), uid);
 	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 		ret = nfs_idmap_lookup_name(id, "user", buf, buflen, idmap);
 	if (ret < 0)
@@ -777,7 +793,7 @@
 	int ret = -EINVAL;
 	__u32 id;
 
-	id = from_kgid(&init_user_ns, gid);
+	id = from_kgid_munged(idmap_userns(idmap), gid);
 	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 		ret = nfs_idmap_lookup_name(id, "group", buf, buflen, idmap);
 	if (ret < 0)