linux/fs/nfs/callback_proc.c

// SPDX-License-Identifier: GPL-2.0
/*
 * linux/fs/nfs/callback_proc.c
 *
 * Copyright (C) 2004 Trond Myklebust
 *
 * NFSv4 callback procedures
 */

#include <linux/errno.h>
#include <linux/math.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/slab.h>
#include <linux/rcupdate.h>
#include <linux/types.h>

#include "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"
#include "internal.h"
#include "pnfs.h"
#include "nfs4session.h"
#include "nfs4trace.h"

#define NFSDBG_FACILITY …

__be32 nfs4_callback_getattr(void *argp, void *resp,
			     struct cb_process_state *cps)
{ … }

__be32 nfs4_callback_recall(void *argp, void *resp,
			    struct cb_process_state *cps)
{ … }

#if defined(CONFIG_NFS_V4_1)

/*
 * Lookup a layout inode by stateid
 *
 * Note: returns a refcount on the inode and superblock
 */
static struct inode *nfs_layout_find_inode_by_stateid(struct nfs_client *clp,
		const nfs4_stateid *stateid)
	__must_hold(RCU)
{ … }

/*
 * Lookup a layout inode by filehandle.
 *
 * Note: returns a refcount on the inode and superblock
 *
 */
static struct inode *nfs_layout_find_inode_by_fh(struct nfs_client *clp,
		const struct nfs_fh *fh)
{ … }

static struct inode *nfs_layout_find_inode(struct nfs_client *clp,
		const struct nfs_fh *fh,
		const nfs4_stateid *stateid)
{ … }

/*
 * Enforce RFC5661 section 12.5.5.2.1. (Layout Recall and Return Sequencing)
 */
static u32 pnfs_check_callback_stateid(struct pnfs_layout_hdr *lo,
					const nfs4_stateid *new,
					struct cb_process_state *cps)
{ … }

static u32 initiate_file_draining(struct nfs_client *clp,
				  struct cb_layoutrecallargs *args,
				  struct cb_process_state *cps)
{ … }

static u32 initiate_bulk_draining(struct nfs_client *clp,
				  struct cb_layoutrecallargs *args)
{ … }

static u32 do_callback_layoutrecall(struct nfs_client *clp,
				    struct cb_layoutrecallargs *args,
				    struct cb_process_state *cps)
{ … }

__be32 nfs4_callback_layoutrecall(void *argp, void *resp,
				  struct cb_process_state *cps)
{ … }

static void pnfs_recall_all_layouts(struct nfs_client *clp,
				    struct cb_process_state *cps)
{ … }

__be32 nfs4_callback_devicenotify(void *argp, void *resp,
				  struct cb_process_state *cps)
{ … }

/*
 * Validate the sequenceID sent by the server.
 * Return success if the sequenceID is one more than what we last saw on
 * this slot, accounting for wraparound.  Increments the slot's sequence.
 *
 * We don't yet implement a duplicate request cache, instead we set the
 * back channel ca_maxresponsesize_cached to zero. This is OK for now
 * since we only currently implement idempotent callbacks anyway.
 *
 * We have a single slot backchannel at this time, so we don't bother
 * checking the used_slots bit array on the table.  The lower layer guarantees
 * a single outstanding callback request at a time.
 */
static __be32
validate_seqid(const struct nfs4_slot_table *tbl, const struct nfs4_slot *slot,
		const struct cb_sequenceargs * args)
{ … }

/*
 * For each referring call triple, check the session's slot table for
 * a match.  If the slot is in use and the sequence numbers match, the
 * client is still waiting for a response to the original request.
 */
static int referring_call_exists(struct nfs_client *clp,
				  uint32_t nrclists,
				  struct referring_call_list *rclists,
				  spinlock_t *lock)
	__releases(lock)
	__acquires(lock)
{ … }

__be32 nfs4_callback_sequence(void *argp, void *resp,
			      struct cb_process_state *cps)
{ … }

static bool
validate_bitmap_values(unsigned int mask)
{ … }

__be32 nfs4_callback_recallany(void *argp, void *resp,
			       struct cb_process_state *cps)
{ … }

/* Reduce the fore channel's max_slots to the target value */
__be32 nfs4_callback_recallslot(void *argp, void *resp,
				struct cb_process_state *cps)
{ … }

__be32 nfs4_callback_notify_lock(void *argp, void *resp,
				 struct cb_process_state *cps)
{ … }
#endif /* CONFIG_NFS_V4_1 */
#ifdef CONFIG_NFS_V4_2
static void nfs4_copy_cb_args(struct nfs4_copy_state *cp_state,
				struct cb_offloadargs *args)
{ … }

__be32 nfs4_callback_offload(void *data, void *dummy,
			     struct cb_process_state *cps)
{ … }
#endif /* CONFIG_NFS_V4_2 */