v4.19.13 snapshot.
diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
new file mode 100644
index 0000000..8f34daf
--- /dev/null
+++ b/fs/nfs/callback.h
@@ -0,0 +1,221 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * linux/fs/nfs/callback.h
+ *
+ * Copyright (C) 2004 Trond Myklebust
+ *
+ * NFSv4 callback definitions
+ */
+#ifndef __LINUX_FS_NFS_CALLBACK_H
+#define __LINUX_FS_NFS_CALLBACK_H
+#include <linux/sunrpc/svc.h>
+
+#define NFS4_CALLBACK 0x40000000
+#define NFS4_CALLBACK_XDRSIZE 2048
+#define NFS4_CALLBACK_BUFSIZE (1024 + NFS4_CALLBACK_XDRSIZE)
+
+enum nfs4_callback_procnum {
+ CB_NULL = 0,
+ CB_COMPOUND = 1,
+};
+
+enum nfs4_callback_opnum {
+ OP_CB_GETATTR = 3,
+ OP_CB_RECALL = 4,
+/* Callback operations new to NFSv4.1 */
+ OP_CB_LAYOUTRECALL = 5,
+ OP_CB_NOTIFY = 6,
+ OP_CB_PUSH_DELEG = 7,
+ OP_CB_RECALL_ANY = 8,
+ OP_CB_RECALLABLE_OBJ_AVAIL = 9,
+ OP_CB_RECALL_SLOT = 10,
+ OP_CB_SEQUENCE = 11,
+ OP_CB_WANTS_CANCELLED = 12,
+ OP_CB_NOTIFY_LOCK = 13,
+ OP_CB_NOTIFY_DEVICEID = 14,
+/* Callback operations new to NFSv4.2 */
+ OP_CB_OFFLOAD = 15,
+ OP_CB_ILLEGAL = 10044,
+};
+
+struct nfs4_slot;
+struct cb_process_state {
+ __be32 drc_status;
+ struct nfs_client *clp;
+ struct nfs4_slot *slot;
+ u32 minorversion;
+ struct net *net;
+};
+
+struct cb_compound_hdr_arg {
+ unsigned int taglen;
+ const char *tag;
+ unsigned int minorversion;
+ unsigned int cb_ident; /* v4.0 callback identifier */
+ unsigned nops;
+};
+
+struct cb_compound_hdr_res {
+ __be32 *status;
+ unsigned int taglen;
+ const char *tag;
+ __be32 *nops;
+};
+
+struct cb_getattrargs {
+ struct nfs_fh fh;
+ uint32_t bitmap[2];
+};
+
+struct cb_getattrres {
+ __be32 status;
+ uint32_t bitmap[2];
+ uint64_t size;
+ uint64_t change_attr;
+ struct timespec ctime;
+ struct timespec mtime;
+};
+
+struct cb_recallargs {
+ struct nfs_fh fh;
+ nfs4_stateid stateid;
+ uint32_t truncate;
+};
+
+#if defined(CONFIG_NFS_V4_1)
+
+struct referring_call {
+ uint32_t rc_sequenceid;
+ uint32_t rc_slotid;
+};
+
+struct referring_call_list {
+ struct nfs4_sessionid rcl_sessionid;
+ uint32_t rcl_nrefcalls;
+ struct referring_call *rcl_refcalls;
+};
+
+struct cb_sequenceargs {
+ struct sockaddr *csa_addr;
+ struct nfs4_sessionid csa_sessionid;
+ uint32_t csa_sequenceid;
+ uint32_t csa_slotid;
+ uint32_t csa_highestslotid;
+ uint32_t csa_cachethis;
+ uint32_t csa_nrclists;
+ struct referring_call_list *csa_rclists;
+};
+
+struct cb_sequenceres {
+ __be32 csr_status;
+ struct nfs4_sessionid csr_sessionid;
+ uint32_t csr_sequenceid;
+ uint32_t csr_slotid;
+ uint32_t csr_highestslotid;
+ uint32_t csr_target_highestslotid;
+};
+
+extern __be32 nfs4_callback_sequence(void *argp, void *resp,
+ struct cb_process_state *cps);
+
+#define RCA4_TYPE_MASK_RDATA_DLG 0
+#define RCA4_TYPE_MASK_WDATA_DLG 1
+#define RCA4_TYPE_MASK_DIR_DLG 2
+#define RCA4_TYPE_MASK_FILE_LAYOUT 3
+#define RCA4_TYPE_MASK_BLK_LAYOUT 4
+#define RCA4_TYPE_MASK_OBJ_LAYOUT_MIN 8
+#define RCA4_TYPE_MASK_OBJ_LAYOUT_MAX 9
+#define RCA4_TYPE_MASK_OTHER_LAYOUT_MIN 12
+#define RCA4_TYPE_MASK_OTHER_LAYOUT_MAX 15
+#define RCA4_TYPE_MASK_ALL 0xf31f
+
+struct cb_recallanyargs {
+ uint32_t craa_objs_to_keep;
+ uint32_t craa_type_mask;
+};
+
+extern __be32 nfs4_callback_recallany(void *argp, void *resp,
+ struct cb_process_state *cps);
+
+struct cb_recallslotargs {
+ uint32_t crsa_target_highest_slotid;
+};
+extern __be32 nfs4_callback_recallslot(void *argp, void *resp,
+ struct cb_process_state *cps);
+
+struct cb_layoutrecallargs {
+ uint32_t cbl_recall_type;
+ uint32_t cbl_layout_type;
+ uint32_t cbl_layoutchanged;
+ union {
+ struct {
+ struct nfs_fh cbl_fh;
+ struct pnfs_layout_range cbl_range;
+ nfs4_stateid cbl_stateid;
+ };
+ struct nfs_fsid cbl_fsid;
+ };
+};
+
+extern __be32 nfs4_callback_layoutrecall(void *argp, void *resp,
+ struct cb_process_state *cps);
+
+struct cb_devicenotifyitem {
+ uint32_t cbd_notify_type;
+ uint32_t cbd_layout_type;
+ struct nfs4_deviceid cbd_dev_id;
+ uint32_t cbd_immediate;
+};
+
+struct cb_devicenotifyargs {
+ int ndevs;
+ struct cb_devicenotifyitem *devs;
+};
+
+extern __be32 nfs4_callback_devicenotify(void *argp, void *resp,
+ struct cb_process_state *cps);
+
+struct cb_notify_lock_args {
+ struct nfs_fh cbnl_fh;
+ struct nfs_lowner cbnl_owner;
+ bool cbnl_valid;
+};
+
+extern __be32 nfs4_callback_notify_lock(void *argp, void *resp,
+ struct cb_process_state *cps);
+#endif /* CONFIG_NFS_V4_1 */
+#ifdef CONFIG_NFS_V4_2
+struct cb_offloadargs {
+ struct nfs_fh coa_fh;
+ nfs4_stateid coa_stateid;
+ uint32_t error;
+ uint64_t wr_count;
+ struct nfs_writeverf wr_writeverf;
+};
+
+extern __be32 nfs4_callback_offload(void *args, void *dummy,
+ struct cb_process_state *cps);
+#endif /* CONFIG_NFS_V4_2 */
+extern int check_gss_callback_principal(struct nfs_client *, struct svc_rqst *);
+extern __be32 nfs4_callback_getattr(void *argp, void *resp,
+ struct cb_process_state *cps);
+extern __be32 nfs4_callback_recall(void *argp, void *resp,
+ struct cb_process_state *cps);
+#if IS_ENABLED(CONFIG_NFS_V4)
+extern int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt);
+extern void nfs_callback_down(int minorversion, struct net *net);
+#endif /* CONFIG_NFS_V4 */
+/*
+ * nfs41: Callbacks are expected to not cause substantial latency,
+ * so we limit their concurrency to 1 by setting up the maximum number
+ * of slots for the backchannel.
+ */
+#define NFS41_BC_MIN_CALLBACKS 1
+#define NFS41_BC_MAX_CALLBACKS 1
+
+#define NFS4_MIN_NR_CALLBACK_THREADS 1
+
+extern unsigned int nfs_callback_set_tcpport;
+extern unsigned short nfs_callback_nr_threads;
+
+#endif /* __LINUX_FS_NFS_CALLBACK_H */