linux/fs/nfsd/localio.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * NFS server support for local clients to bypass network stack
 *
 * Copyright (C) 2014 Weston Andros Adamson <[email protected]>
 * Copyright (C) 2019 Trond Myklebust <[email protected]>
 * Copyright (C) 2024 Mike Snitzer <[email protected]>
 * Copyright (C) 2024 NeilBrown <[email protected]>
 */

#include <linux/exportfs.h>
#include <linux/sunrpc/svcauth.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs_common.h>
#include <linux/nfslocalio.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_xdr.h>
#include <linux/string.h>

#include "nfsd.h"
#include "vfs.h"
#include "netns.h"
#include "filecache.h"
#include "cache.h"

static const struct nfsd_localio_operations nfsd_localio_ops = …;

void nfsd_localio_ops_init(void)
{ … }

/**
 * nfsd_open_local_fh - lookup a local filehandle @nfs_fh and map to nfsd_file
 *
 * @net: 'struct net' to get the proper nfsd_net required for LOCALIO access
 * @dom: 'struct auth_domain' required for LOCALIO access
 * @rpc_clnt: rpc_clnt that the client established
 * @cred: cred that the client established
 * @nfs_fh: filehandle to lookup
 * @fmode: fmode_t to use for open
 *
 * This function maps a local fh to a path on a local filesystem.
 * This is useful when the nfs client has the local server mounted - it can
 * avoid all the NFS overhead with reads, writes and commits.
 *
 * On successful return, returned nfsd_file will have its nf_net member
 * set. Caller (NFS client) is responsible for calling nfsd_serv_put and
 * nfsd_file_put (via nfs_to_nfsd_file_put_local).
 */
struct nfsd_file *
nfsd_open_local_fh(struct net *net, struct auth_domain *dom,
		   struct rpc_clnt *rpc_clnt, const struct cred *cred,
		   const struct nfs_fh *nfs_fh, const fmode_t fmode)
{ … }
EXPORT_SYMBOL_GPL(…);

/*
 * UUID_IS_LOCAL XDR functions
 */

static __be32 localio_proc_null(struct svc_rqst *rqstp)
{ … }

struct localio_uuidarg { … };

static __be32 localio_proc_uuid_is_local(struct svc_rqst *rqstp)
{ … }

static bool localio_decode_uuidarg(struct svc_rqst *rqstp,
				   struct xdr_stream *xdr)
{ … }

static const struct svc_procedure localio_procedures1[] = …;

#define LOCALIO_NR_PROCEDURES …
static DEFINE_PER_CPU_ALIGNED(unsigned long,
			      localio_count[LOCALIO_NR_PROCEDURES]);
const struct svc_version localio_version1 = …;