Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 0668999..af29475 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -17,10 +17,12 @@
 #include <linux/nfs3.h>
 #include <linux/nfs4.h>
 #include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/svc_xprt.h>
 #include <linux/sunrpc/msg_prot.h>
 
 #include <uapi/linux/nfsd/debug.h>
 
+#include "netns.h"
 #include "stats.h"
 #include "export.h"
 
@@ -73,7 +75,7 @@
 /*
  * Function prototypes.
  */
-int		nfsd_svc(int nrservs, struct net *net);
+int		nfsd_svc(int nrservs, struct net *net, const struct cred *cred);
 int		nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp);
 
 int		nfsd_nrthreads(struct net *);
@@ -85,6 +87,16 @@
 
 void		nfsd_destroy(struct net *net);
 
+struct nfsdfs_client {
+	struct kref cl_ref;
+	void (*cl_release)(struct kref *kref);
+};
+
+struct nfsdfs_client *get_nfsdfs_client(struct inode *);
+struct dentry *nfsd_client_mkdir(struct nfsd_net *nn,
+		struct nfsdfs_client *ncl, u32 id, const struct tree_descr *);
+void nfsd_client_rmdir(struct dentry *dentry);
+
 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
 #ifdef CONFIG_NFSD_V2_ACL
 extern const struct svc_version nfsd_acl_version2;
@@ -98,10 +110,12 @@
 #endif
 #endif
 
+struct nfsd_net;
+
 enum vers_op {NFSD_SET, NFSD_CLEAR, NFSD_TEST, NFSD_AVAIL };
-int nfsd_vers(int vers, enum vers_op change);
-int nfsd_minorversion(u32 minorversion, enum vers_op change);
-void nfsd_reset_versions(void);
+int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change);
+int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change);
+void nfsd_reset_versions(struct nfsd_net *nn);
 int nfsd_create_serv(struct net *net);
 
 extern int nfsd_max_blksize;
@@ -110,6 +124,12 @@
 {
 	return rq->rq_prog == NFS_PROGRAM && rq->rq_vers == 4;
 }
+static inline struct user_namespace *
+nfsd_user_namespace(const struct svc_rqst *rqstp)
+{
+	const struct cred *cred = rqstp->rq_xprt->xpt_cred;
+	return cred ? cred->user_ns : &init_user_ns;
+}
 
 /* 
  * NFSv4 State