path: root/fs/nfs/client.c

/* client.c: NFS client sharing and management code
 *
 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */


#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/metrics.h>
#include <linux/sunrpc/xprtsock.h>
#include <linux/sunrpc/xprtrdma.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/nfs4_mount.h>
#include <linux/lockd/bind.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
#include <linux/nfs_idmap.h>
#include <linux/vfs.h>
#include <linux/inet.h>
#include <linux/in6.h>
#include <net/ipv6.h>
#include <linux/nfs_xdr.h>

#include <asm/system.h>

#include "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"
#include "iostat.h"
#include "internal.h"

#define NFSDBG_FACILITY		NFSDBG_CLIENT

static DEFINE_SPINLOCK(nfs_client_lock);
static LIST_HEAD(nfs_client_list);
static LIST_HEAD(nfs_volume_list);
static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);

/*
 * RPC cruft for NFS
 */
static struct rpc_version *nfs_version[5] = {
	[2]			= &nfs_version2,
#ifdef CONFIG_NFS_V3
	[3]			= &nfs_version3,
#endif
#ifdef CONFIG_NFS_V4
	[4]			= &nfs_version4,
#endif
};

struct rpc_program nfs_program = {
	.name			= "nfs",
	.number			= NFS_PROGRAM,
	.nrvers			= ARRAY_SIZE(nfs_version),
	.version		= nfs_version,
	.stats			= &nfs_rpcstat,
	.pipe_dir_name		= "/nfs",
};

struct rpc_stat nfs_rpcstat = {
	.program		= &nfs_program
};


#ifdef CONFIG_NFS_V3_ACL
static struct rpc_stat		nfsacl_rpcstat = { &nfsacl_program };
static struct rpc_version *	nfsacl_version[] = {
	[3]			= &nfsacl_version3,
};

struct rpc_program		nfsacl_program = {
	.name			= "nfsacl",
	.number			= NFS_ACL_PROGRAM,
	.nrvers			= ARRAY_SIZE(nfsacl_version),
	.version		= nfsacl_version,
	.stats			= &nfsacl_rpcstat,
};
#endif  /* CONFIG_NFS_V3_ACL */

struct nfs_client_initdata {
	const char *hostname;
	const struct sockaddr *addr;
	size_t addrlen;
	const struct nfs_rpc_ops *rpc_ops;
	int proto;
};

/*
 * Allocate a shared client record
 *
 * Since these are allocated/deallocated very rarely, we don't
 * bother putting them in a slab cache...
 */
static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
{
	struct nfs_client *clp;
	struct rpc_cred *cred;

	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
		goto error_0;

	clp->rpc_ops = cl_init->rpc_ops;

	if (cl_init->rpc_ops->version == 4) {
		if (nfs_callback_up() < 0)
			goto error_2;
		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
	}

	atomic_set(&clp->cl_count, 1);
	clp->cl_cons_state = NFS_CS_INITING;

	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
	clp->cl_addrlen = cl_init->addrlen;

	if (cl_init->hostname) {
		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
		if (!clp->cl_hostname)
			goto error_3;
	}

	INIT_LIST_HEAD(&clp->cl_superblocks);
	clp->cl_rpcclient = ERR_PTR(-EINVAL);

	clp->cl_proto = cl_init->proto;

#ifdef CONFIG_NFS_V4
	init_rwsem(&clp->cl_sem);
	INIT_LIST_HEAD(&clp->cl_delegations);
	spin_lock_init(&clp->cl_lock);
	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
	clp->cl_boot_time = CURRENT_TIME;
	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
#endif
	cred = rpc_lookup_machine_cred();
	if (!IS_ERR(cred))
		clp->cl_machine_cred = cred;

	return clp;

error_3:
	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
		nfs_callback_down();
error_2:
	kfree(clp);
error_0:
	return NULL;
}

static void nfs4_shutdown_client(struct nfs_client *clp)
{
#ifdef CONFIG_NFS_V4
	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
		nfs4_kill_renewd(clp);
	BUG_ON(!RB_EMPTY_ROOT(&clp->cl_state_owners));
	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
		nfs_idmap_delete(clp);

	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
#endif
}

/*
 * Destroy a shared client record
 */
static void nfs_free_client(struct nfs_client *clp)
{
	dprintk("--> nfs_free_client(%u)\n", clp->rpc_ops->version);

	nfs4_shutdown_client(clp);

	/* -EIO all pending I/O */
	if (!IS_ERR(clp->cl_rpcclient))
		rpc_shutdown_client(clp->cl_rpcclient);

	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
		nfs_callback_down();

	if (clp->cl_machine_cred != NULL)
		put_rpccred(clp->cl_machine_cred);

	kfree(clp->cl_hostname);
	kfree(clp);

	dprintk("<-- nfs_free_client()\n");
}

/*
 * Release a reference to a shared client record
 */
void nfs_put_client(struct nfs_client *clp)
{
	if (!clp)
		return;

	dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count));

	if (atomic_dec_and_lock(&clp->cl_count, &nfs_client_lock)) {
		list_del(&clp->cl_share_link);
		spin_unlock(&nfs_client_lock);

		BUG_ON(!list_empty(&clp->cl_superblocks));

		nfs_free_client(clp);
	}
}

static int nfs_sockaddr_match_ipaddr4(const struct sockaddr_in *sa1,
				 const struct sockaddr_in *sa2)
{
	return sa1->sin_addr.s_addr == sa2->sin_addr.s_addr;
}

static int nfs_sockaddr_match_ipaddr6(const struct sockaddr_in6 *sa1,
				 const struct sockaddr_in6 *sa2)
{
	return ipv6_addr_equal(&sa1->sin6_addr, &sa2->sin6_addr);
}

static int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
				 const struct sockaddr *sa2)
{
	switch (sa1->sa_family) {
	case AF_INET:
		return nfs_sockaddr_match_ipaddr4((const struct sockaddr_in *)sa1,
				(const struct sockaddr_in *)sa2);
	case AF_INET6:
		return nfs_sockaddr_match_ipaddr6((const struct sockaddr_in6 *)sa1,
				(const struct sockaddr_in6 *)sa2);
	}
	BUG();
}

/*
 * Find a client by IP address and protocol version
 * - returns NULL if no such client
 */
struct nfs_client *nfs_find_client(const struct sockaddr *addr, u32 nfsversion)
{
	struct nfs_client *clp;

	spin_lock(&nfs_client_lock);
	list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
		struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;

		/* Don't match clients that failed to initialise properly */
		if (clp->cl_cons_state != NFS_CS_READY)
			continue;

		/* Different NFS versions cannot share the same nfs_client */
		if (clp->rpc_ops->version != nfsversion)
			continue;

		if (addr->sa_family != clap->sa_family)
			continue;
		/* Match only the IP address, not the port number */
		if (!nfs_sockaddr_match_ipaddr(addr, clap))
			continue;