linux/fs/nfs/namespace.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/fs/nfs/namespace.c
 *
 * Copyright (C) 2005 Trond Myklebust <[email protected]>
 * - Modified by David Howells <[email protected]>
 *
 * NFS namespace
 */

#include <linux/module.h>
#include <linux/dcache.h>
#include <linux/gfp.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/nfs_fs.h>
#include <linux/string.h>
#include <linux/sunrpc/clnt.h>
#include <linux/vfs.h>
#include <linux/sunrpc/gss_api.h>
#include "internal.h"
#include "nfs.h"

#define NFSDBG_FACILITY …

static void nfs_expire_automounts(struct work_struct *work);

static LIST_HEAD(nfs_automount_list);
static DECLARE_DELAYED_WORK(nfs_automount_task, nfs_expire_automounts);
int nfs_mountpoint_expiry_timeout = …;

/*
 * nfs_path - reconstruct the path given an arbitrary dentry
 * @base - used to return pointer to the end of devname part of path
 * @dentry_in - pointer to dentry
 * @buffer - result buffer
 * @buflen_in - length of buffer
 * @flags - options (see below)
 *
 * Helper function for constructing the server pathname
 * by arbitrary hashed dentry.
 *
 * This is mainly for use in figuring out the path on the
 * server side when automounting on top of an existing partition
 * and in generating /proc/mounts and friends.
 *
 * Supported flags:
 * NFS_PATH_CANONICAL: ensure there is exactly one slash after
 *		       the original device (export) name
 *		       (if unset, the original name is returned verbatim)
 */
char *nfs_path(char **p, struct dentry *dentry_in, char *buffer,
	       ssize_t buflen_in, unsigned flags)
{ … }
EXPORT_SYMBOL_GPL(…);

/*
 * nfs_d_automount - Handle crossing a mountpoint on the server
 * @path - The mountpoint
 *
 * When we encounter a mountpoint on the server, we want to set up
 * a mountpoint on the client too, to prevent inode numbers from
 * colliding, and to allow "df" to work properly.
 * On NFSv4, we also want to allow for the fact that different
 * filesystems may be migrated to different servers in a failover
 * situation, and that different filesystems may want to use
 * different security flavours.
 */
struct vfsmount *nfs_d_automount(struct path *path)
{ … }

static int
nfs_namespace_getattr(struct mnt_idmap *idmap,
		      const struct path *path, struct kstat *stat,
		      u32 request_mask, unsigned int query_flags)
{ … }

static int
nfs_namespace_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
		      struct iattr *attr)
{ … }

const struct inode_operations nfs_mountpoint_inode_operations = …;

const struct inode_operations nfs_referral_inode_operations = …;

static void nfs_expire_automounts(struct work_struct *work)
{ … }

void nfs_release_automount_timer(void)
{ … }

/**
 * nfs_do_submount - set up mountpoint when crossing a filesystem boundary
 * @fc: pointer to struct nfs_fs_context
 *
 */
int nfs_do_submount(struct fs_context *fc)
{ … }
EXPORT_SYMBOL_GPL(…);

int nfs_submount(struct fs_context *fc, struct nfs_server *server)
{ … }
EXPORT_SYMBOL_GPL(…);

static int param_set_nfs_timeout(const char *val, const struct kernel_param *kp)
{ … }

static int param_get_nfs_timeout(char *buffer, const struct kernel_param *kp)
{ … }

static const struct kernel_param_ops param_ops_nfs_timeout = …;
#define param_check_nfs_timeout(name, p) …

module_param(nfs_mountpoint_expiry_timeout, nfs_timeout, 0644);
MODULE_PARM_DESC(…) …;