super.c 77.3 KB
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// SPDX-License-Identifier: GPL-2.0-only
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/*
 *  linux/fs/nfs/super.c
 *
 *  Copyright (C) 1992  Rick Sladkey
 *
 *  nfs superblock handling functions
 *
 *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
 *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
 *
 *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
 *  J.S.Peatfield@damtp.cam.ac.uk
 *
 *  Split from inode.c by David Howells <dhowells@redhat.com>
 *
 * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
 *   particular server are held in the same superblock
 * - NFS superblocks can have several effective roots to the dentry tree
 * - directory type roots are spliced into the tree when a path from one root reaches the root
 *   of another (see nfs_lookup())
 */

#include <linux/module.h>
#include <linux/init.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/addr.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/namei.h>
#include <linux/vfs.h>
#include <linux/inet.h>
#include <linux/in6.h>
#include <linux/slab.h>
#include <net/ipv6.h>
#include <linux/netdevice.h>
#include <linux/nfs_xdr.h>
#include <linux/magic.h>
#include <linux/parser.h>
#include <linux/nsproxy.h>
#include <linux/rcupdate.h>

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#include <linux/uaccess.h>
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#include "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"
#include "iostat.h"
#include "internal.h"
#include "fscache.h"
#include "nfs4session.h"
#include "pnfs.h"
#include "nfs.h"

#define NFSDBG_FACILITY		NFSDBG_VFS
#define NFS_TEXT_DATA		1

#if IS_ENABLED(CONFIG_NFS_V3)
#define NFS_DEFAULT_VERSION 3
#else
#define NFS_DEFAULT_VERSION 2
#endif

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#define NFS_MAX_CONNECTIONS 16

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enum {
	/* Mount options that take no arguments */
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	Opt_soft, Opt_softerr, Opt_hard,
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	Opt_posix, Opt_noposix,
	Opt_cto, Opt_nocto,
	Opt_ac, Opt_noac,
	Opt_lock, Opt_nolock,
	Opt_udp, Opt_tcp, Opt_rdma,
	Opt_acl, Opt_noacl,
	Opt_rdirplus, Opt_nordirplus,
	Opt_sharecache, Opt_nosharecache,
	Opt_resvport, Opt_noresvport,
	Opt_fscache, Opt_nofscache,
	Opt_migration, Opt_nomigration,

	/* Mount options that take integer arguments */
	Opt_port,
	Opt_rsize, Opt_wsize, Opt_bsize,
	Opt_timeo, Opt_retrans,
	Opt_acregmin, Opt_acregmax,
	Opt_acdirmin, Opt_acdirmax,
	Opt_actimeo,
	Opt_namelen,
	Opt_mountport,
	Opt_mountvers,
	Opt_minorversion,

	/* Mount options that take string arguments */
	Opt_nfsvers,
	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
	Opt_addr, Opt_mountaddr, Opt_clientaddr,
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	Opt_nconnect,
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	Opt_lookupcache,
	Opt_fscache_uniq,
	Opt_local_lock,

	/* Special mount options */
	Opt_userspace, Opt_deprecated, Opt_sloppy,

	Opt_err
};

static const match_table_t nfs_mount_option_tokens = {
	{ Opt_userspace, "bg" },
	{ Opt_userspace, "fg" },
	{ Opt_userspace, "retry=%s" },

	{ Opt_sloppy, "sloppy" },

	{ Opt_soft, "soft" },
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	{ Opt_softerr, "softerr" },
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	{ Opt_hard, "hard" },
	{ Opt_deprecated, "intr" },
	{ Opt_deprecated, "nointr" },
	{ Opt_posix, "posix" },
	{ Opt_noposix, "noposix" },
	{ Opt_cto, "cto" },
	{ Opt_nocto, "nocto" },
	{ Opt_ac, "ac" },
	{ Opt_noac, "noac" },
	{ Opt_lock, "lock" },
	{ Opt_nolock, "nolock" },
	{ Opt_udp, "udp" },
	{ Opt_tcp, "tcp" },
	{ Opt_rdma, "rdma" },
	{ Opt_acl, "acl" },
	{ Opt_noacl, "noacl" },
	{ Opt_rdirplus, "rdirplus" },
	{ Opt_nordirplus, "nordirplus" },
	{ Opt_sharecache, "sharecache" },
	{ Opt_nosharecache, "nosharecache" },
	{ Opt_resvport, "resvport" },
	{ Opt_noresvport, "noresvport" },
	{ Opt_fscache, "fsc" },
	{ Opt_nofscache, "nofsc" },
	{ Opt_migration, "migration" },
	{ Opt_nomigration, "nomigration" },

	{ Opt_port, "port=%s" },
	{ Opt_rsize, "rsize=%s" },
	{ Opt_wsize, "wsize=%s" },
	{ Opt_bsize, "bsize=%s" },
	{ Opt_timeo, "timeo=%s" },
	{ Opt_retrans, "retrans=%s" },
	{ Opt_acregmin, "acregmin=%s" },
	{ Opt_acregmax, "acregmax=%s" },
	{ Opt_acdirmin, "acdirmin=%s" },
	{ Opt_acdirmax, "acdirmax=%s" },
	{ Opt_actimeo, "actimeo=%s" },
	{ Opt_namelen, "namlen=%s" },
	{ Opt_mountport, "mountport=%s" },
	{ Opt_mountvers, "mountvers=%s" },
	{ Opt_minorversion, "minorversion=%s" },

	{ Opt_nfsvers, "nfsvers=%s" },
	{ Opt_nfsvers, "vers=%s" },

	{ Opt_sec, "sec=%s" },
	{ Opt_proto, "proto=%s" },
	{ Opt_mountproto, "mountproto=%s" },
	{ Opt_addr, "addr=%s" },
	{ Opt_clientaddr, "clientaddr=%s" },
	{ Opt_mounthost, "mounthost=%s" },
	{ Opt_mountaddr, "mountaddr=%s" },

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	{ Opt_nconnect, "nconnect=%s" },

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	{ Opt_lookupcache, "lookupcache=%s" },
	{ Opt_fscache_uniq, "fsc=%s" },
	{ Opt_local_lock, "local_lock=%s" },

	/* The following needs to be listed after all other options */
	{ Opt_nfsvers, "v%s" },

	{ Opt_err, NULL }
};

enum {
	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
	Opt_xprt_rdma6,

	Opt_xprt_err
};

static const match_table_t nfs_xprt_protocol_tokens = {
	{ Opt_xprt_udp, "udp" },
	{ Opt_xprt_udp6, "udp6" },
	{ Opt_xprt_tcp, "tcp" },
	{ Opt_xprt_tcp6, "tcp6" },
	{ Opt_xprt_rdma, "rdma" },
	{ Opt_xprt_rdma6, "rdma6" },

	{ Opt_xprt_err, NULL }
};

enum {
	Opt_sec_none, Opt_sec_sys,
	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,

	Opt_sec_err
};

static const match_table_t nfs_secflavor_tokens = {
	{ Opt_sec_none, "none" },
	{ Opt_sec_none, "null" },
	{ Opt_sec_sys, "sys" },

	{ Opt_sec_krb5, "krb5" },
	{ Opt_sec_krb5i, "krb5i" },
	{ Opt_sec_krb5p, "krb5p" },

	{ Opt_sec_lkey, "lkey" },
	{ Opt_sec_lkeyi, "lkeyi" },
	{ Opt_sec_lkeyp, "lkeyp" },

	{ Opt_sec_spkm, "spkm3" },
	{ Opt_sec_spkmi, "spkm3i" },
	{ Opt_sec_spkmp, "spkm3p" },

	{ Opt_sec_err, NULL }
};

enum {
	Opt_lookupcache_all, Opt_lookupcache_positive,
	Opt_lookupcache_none,

	Opt_lookupcache_err
};

static match_table_t nfs_lookupcache_tokens = {
	{ Opt_lookupcache_all, "all" },
	{ Opt_lookupcache_positive, "pos" },
	{ Opt_lookupcache_positive, "positive" },
	{ Opt_lookupcache_none, "none" },

	{ Opt_lookupcache_err, NULL }
};

enum {
	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
	Opt_local_lock_none,

	Opt_local_lock_err
};

static match_table_t nfs_local_lock_tokens = {
	{ Opt_local_lock_all, "all" },
	{ Opt_local_lock_flock, "flock" },
	{ Opt_local_lock_posix, "posix" },
	{ Opt_local_lock_none, "none" },

	{ Opt_local_lock_err, NULL }
};

enum {
	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
	Opt_vers_4_1, Opt_vers_4_2,

	Opt_vers_err
};

static match_table_t nfs_vers_tokens = {
	{ Opt_vers_2, "2" },
	{ Opt_vers_3, "3" },
	{ Opt_vers_4, "4" },
	{ Opt_vers_4_0, "4.0" },
	{ Opt_vers_4_1, "4.1" },
	{ Opt_vers_4_2, "4.2" },

	{ Opt_vers_err, NULL }
};

static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
		int flags, const char *dev_name, void *raw_data);

struct file_system_type nfs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "nfs",
	.mount		= nfs_fs_mount,
	.kill_sb	= nfs_kill_super,
	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
};
MODULE_ALIAS_FS("nfs");
EXPORT_SYMBOL_GPL(nfs_fs_type);

struct file_system_type nfs_xdev_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "nfs",
	.mount		= nfs_xdev_mount,
	.kill_sb	= nfs_kill_super,
	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
};

const struct super_operations nfs_sops = {
	.alloc_inode	= nfs_alloc_inode,
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	.free_inode	= nfs_free_inode,
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	.write_inode	= nfs_write_inode,
	.drop_inode	= nfs_drop_inode,
	.statfs		= nfs_statfs,
	.evict_inode	= nfs_evict_inode,
	.umount_begin	= nfs_umount_begin,
	.show_options	= nfs_show_options,
	.show_devname	= nfs_show_devname,
	.show_path	= nfs_show_path,
	.show_stats	= nfs_show_stats,
	.remount_fs	= nfs_remount,
};
EXPORT_SYMBOL_GPL(nfs_sops);

#if IS_ENABLED(CONFIG_NFS_V4)
static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
static int nfs4_validate_mount_data(void *options,
	struct nfs_parsed_mount_data *args, const char *dev_name);

struct file_system_type nfs4_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "nfs4",
	.mount		= nfs_fs_mount,
	.kill_sb	= nfs_kill_super,
	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
};
MODULE_ALIAS_FS("nfs4");
MODULE_ALIAS("nfs4");
EXPORT_SYMBOL_GPL(nfs4_fs_type);

static int __init register_nfs4_fs(void)
{
	return register_filesystem(&nfs4_fs_type);
}

static void unregister_nfs4_fs(void)
{
	unregister_filesystem(&nfs4_fs_type);
}
#else
static int __init register_nfs4_fs(void)
{
	return 0;
}

static void unregister_nfs4_fs(void)
{
}
#endif

static struct shrinker acl_shrinker = {
	.count_objects	= nfs_access_cache_count,
	.scan_objects	= nfs_access_cache_scan,
	.seeks		= DEFAULT_SEEKS,
};

/*
 * Register the NFS filesystems
 */
int __init register_nfs_fs(void)
{
	int ret;

        ret = register_filesystem(&nfs_fs_type);
	if (ret < 0)
		goto error_0;

	ret = register_nfs4_fs();
	if (ret < 0)
		goto error_1;

	ret = nfs_register_sysctl();
	if (ret < 0)
		goto error_2;
	ret = register_shrinker(&acl_shrinker);
	if (ret < 0)
		goto error_3;
	return 0;
error_3:
	nfs_unregister_sysctl();
error_2:
	unregister_nfs4_fs();
error_1:
	unregister_filesystem(&nfs_fs_type);
error_0:
	return ret;
}

/*
 * Unregister the NFS filesystems
 */
void __exit unregister_nfs_fs(void)
{
	unregister_shrinker(&acl_shrinker);
	nfs_unregister_sysctl();
	unregister_nfs4_fs();
	unregister_filesystem(&nfs_fs_type);
}

bool nfs_sb_active(struct super_block *sb)
{
	struct nfs_server *server = NFS_SB(sb);

	if (!atomic_inc_not_zero(&sb->s_active))
		return false;
	if (atomic_inc_return(&server->active) != 1)
		atomic_dec(&sb->s_active);
	return true;
}
EXPORT_SYMBOL_GPL(nfs_sb_active);

void nfs_sb_deactive(struct super_block *sb)
{
	struct nfs_server *server = NFS_SB(sb);

	if (atomic_dec_and_test(&server->active))
		deactivate_super(sb);
}
EXPORT_SYMBOL_GPL(nfs_sb_deactive);

/*
 * Deliver file system statistics to userspace
 */
int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct nfs_server *server = NFS_SB(dentry->d_sb);
	unsigned char blockbits;
	unsigned long blockres;
	struct nfs_fh *fh = NFS_FH(d_inode(dentry));
	struct nfs_fsstat res;
	int error = -ENOMEM;

	res.fattr = nfs_alloc_fattr();
	if (res.fattr == NULL)
		goto out_err;

	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
	if (unlikely(error == -ESTALE)) {
		struct dentry *pd_dentry;

		pd_dentry = dget_parent(dentry);
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		nfs_zap_caches(d_inode(pd_dentry));
		dput(pd_dentry);
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	}
	nfs_free_fattr(res.fattr);
	if (error < 0)
		goto out_err;

	buf->f_type = NFS_SUPER_MAGIC;

	/*
	 * Current versions of glibc do not correctly handle the
	 * case where f_frsize != f_bsize.  Eventually we want to
	 * report the value of wtmult in this field.
	 */
	buf->f_frsize = dentry->d_sb->s_blocksize;

	/*
	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
	 * are reported in units of f_frsize.  Linux hasn't had
	 * an f_frsize field in its statfs struct until recently,
	 * thus historically Linux's sys_statfs reports these
	 * fields in units of f_bsize.
	 */
	buf->f_bsize = dentry->d_sb->s_blocksize;
	blockbits = dentry->d_sb->s_blocksize_bits;
	blockres = (1 << blockbits) - 1;
	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
	buf->f_bavail = (res.abytes + blockres) >> blockbits;

	buf->f_files = res.tfiles;
	buf->f_ffree = res.afiles;

	buf->f_namelen = server->namelen;

	return 0;

 out_err:
	dprintk("%s: statfs error = %d\n", __func__, -error);
	return error;
}
EXPORT_SYMBOL_GPL(nfs_statfs);

/*
 * Map the security flavour number to a name
 */
static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
{
	static const struct {
		rpc_authflavor_t flavour;
		const char *str;
	} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
		/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
		{ RPC_AUTH_NULL, "null" },
		{ RPC_AUTH_UNIX, "sys" },
		{ RPC_AUTH_GSS_KRB5, "krb5" },
		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
		{ RPC_AUTH_GSS_LKEY, "lkey" },
		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
		{ RPC_AUTH_GSS_SPKM, "spkm" },
		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
		{ UINT_MAX, "unknown" }
	};
	int i;

	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
		if (sec_flavours[i].flavour == flavour)
			break;
	}
	return sec_flavours[i].str;
}

static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
				  int showdefaults)
{
	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
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	char *proto = NULL;
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	switch (sap->sa_family) {
	case AF_INET:
		switch (nfss->mountd_protocol) {
		case IPPROTO_UDP:
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			proto = RPCBIND_NETID_UDP;
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			break;
		case IPPROTO_TCP:
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			proto = RPCBIND_NETID_TCP;
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			break;
		}
		break;
	case AF_INET6:
		switch (nfss->mountd_protocol) {
		case IPPROTO_UDP:
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			proto = RPCBIND_NETID_UDP6;
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			break;
		case IPPROTO_TCP:
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			proto = RPCBIND_NETID_TCP6;
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			break;
		}
		break;
	}
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	if (proto || showdefaults)
		seq_printf(m, ",mountproto=%s", proto ?: "auto");
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}

static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
				    int showdefaults)
{
	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;

	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
		return;

	switch (sap->sa_family) {
	case AF_INET: {
		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
		break;
	}
	case AF_INET6: {
		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
		break;
	}
	default:
		if (showdefaults)
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			seq_puts(m, ",mountaddr=unspecified");
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	}

	if (nfss->mountd_version || showdefaults)
		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
	if ((nfss->mountd_port &&
		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
		showdefaults)
		seq_printf(m, ",mountport=%u", nfss->mountd_port);

	nfs_show_mountd_netid(m, nfss, showdefaults);
}

#if IS_ENABLED(CONFIG_NFS_V4)
static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
				    int showdefaults)
{
	struct nfs_client *clp = nfss->nfs_client;

	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
}
#else
static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
				    int showdefaults)
{
}
#endif

static void nfs_show_nfs_version(struct seq_file *m,
		unsigned int version,
		unsigned int minorversion)
{
	seq_printf(m, ",vers=%u", version);
	if (version == 4)
		seq_printf(m, ".%u", minorversion);
}

/*
 * Describe the mount options in force on this server representation
 */
static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
				   int showdefaults)
{
	static const struct proc_nfs_info {
		int flag;
		const char *str;
		const char *nostr;
	} nfs_info[] = {
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		{ NFS_MOUNT_SOFT, ",soft", "" },
		{ NFS_MOUNT_SOFTERR, ",softerr", "" },
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		{ NFS_MOUNT_POSIX, ",posix", "" },
		{ NFS_MOUNT_NOCTO, ",nocto", "" },
		{ NFS_MOUNT_NOAC, ",noac", "" },
		{ NFS_MOUNT_NONLM, ",nolock", "" },
		{ NFS_MOUNT_NOACL, ",noacl", "" },
		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
		{ 0, NULL, NULL }
	};
	const struct proc_nfs_info *nfs_infop;
	struct nfs_client *clp = nfss->nfs_client;
	u32 version = clp->rpc_ops->version;
	int local_flock, local_fcntl;

	nfs_show_nfs_version(m, version, clp->cl_minorversion);
	seq_printf(m, ",rsize=%u", nfss->rsize);
	seq_printf(m, ",wsize=%u", nfss->wsize);
	if (nfss->bsize != 0)
		seq_printf(m, ",bsize=%u", nfss->bsize);
	seq_printf(m, ",namlen=%u", nfss->namelen);
	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
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	if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR)))
			seq_puts(m, ",hard");
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	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
		if (nfss->flags & nfs_infop->flag)
			seq_puts(m, nfs_infop->str);
		else
			seq_puts(m, nfs_infop->nostr);
	}
	rcu_read_lock();
	seq_printf(m, ",proto=%s",
		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
	rcu_read_unlock();
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	if (clp->cl_nconnect > 0)
		seq_printf(m, ",nconnect=%u", clp->cl_nconnect);
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	if (version == 4) {
		if (nfss->port != NFS_PORT)
			seq_printf(m, ",port=%u", nfss->port);
	} else
		if (nfss->port)
			seq_printf(m, ",port=%u", nfss->port);

	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));

	if (version != 4)
		nfs_show_mountd_options(m, nfss, showdefaults);
	else
		nfs_show_nfsv4_options(m, nfss, showdefaults);

	if (nfss->options & NFS_OPTION_FSCACHE)
698
		seq_puts(m, ",fsc");
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	if (nfss->options & NFS_OPTION_MIGRATION)
701
		seq_puts(m, ",migration");
702 703 704

	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
705
			seq_puts(m, ",lookupcache=none");
706
		else
707
			seq_puts(m, ",lookupcache=pos");
708 709 710 711 712 713
	}

	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;

	if (!local_flock && !local_fcntl)
714
		seq_puts(m, ",local_lock=none");
715
	else if (local_flock && local_fcntl)
716
		seq_puts(m, ",local_lock=all");
717
	else if (local_flock)
718
		seq_puts(m, ",local_lock=flock");
719
	else
720
		seq_puts(m, ",local_lock=posix");
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}

/*
 * Describe the mount options on this VFS mountpoint
 */
int nfs_show_options(struct seq_file *m, struct dentry *root)
{
	struct nfs_server *nfss = NFS_SB(root->d_sb);

	nfs_show_mount_options(m, nfss, 0);

	rcu_read_lock();
	seq_printf(m, ",addr=%s",
			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
							RPC_DISPLAY_ADDR));
	rcu_read_unlock();

	return 0;
}
EXPORT_SYMBOL_GPL(nfs_show_options);

#if IS_ENABLED(CONFIG_NFS_V4)
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static void show_lease(struct seq_file *m, struct nfs_server *server)
{
	struct nfs_client *clp = server->nfs_client;
	unsigned long expire;

	seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ);
	expire = clp->cl_last_renewal + clp->cl_lease_time;
	seq_printf(m, ",lease_expired=%ld",
		   time_after(expire, jiffies) ?  0 : (jiffies - expire) / HZ);
}
753 754 755 756
#ifdef CONFIG_NFS_V4_1
static void show_sessions(struct seq_file *m, struct nfs_server *server)
{
	if (nfs4_has_session(server->nfs_client))
757
		seq_puts(m, ",sessions");
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}
#else
static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
#endif
#endif

#ifdef CONFIG_NFS_V4_1
static void show_pnfs(struct seq_file *m, struct nfs_server *server)
{
	seq_printf(m, ",pnfs=");
	if (server->pnfs_curr_ld)
		seq_printf(m, "%s", server->pnfs_curr_ld->name);
	else
		seq_printf(m, "not configured");
}

static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
{
	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
			   "date='%llu,%u'",
			   impl_id->name, impl_id->domain,
			   impl_id->date.seconds, impl_id->date.nseconds);
	}
}
#else
#if IS_ENABLED(CONFIG_NFS_V4)
static void show_pnfs(struct seq_file *m, struct nfs_server *server)
{
}
#endif
static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
{
}
#endif

int nfs_show_devname(struct seq_file *m, struct dentry *root)
{
	char *page = (char *) __get_free_page(GFP_KERNEL);
	char *devname, *dummy;
	int err = 0;
	if (!page)
		return -ENOMEM;
	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
	if (IS_ERR(devname))
		err = PTR_ERR(devname);
	else
		seq_escape(m, devname, " \t\n\\");
	free_page((unsigned long)page);
	return err;
}
EXPORT_SYMBOL_GPL(nfs_show_devname);

int nfs_show_path(struct seq_file *m, struct dentry *dentry)
{
	seq_puts(m, "/");
	return 0;
}
EXPORT_SYMBOL_GPL(nfs_show_path);

/*
 * Present statistical information for this VFS mountpoint
 */
int nfs_show_stats(struct seq_file *m, struct dentry *root)
{
	int i, cpu;
	struct nfs_server *nfss = NFS_SB(root->d_sb);
	struct rpc_auth *auth = nfss->client->cl_auth;
	struct nfs_iostats totals = { };

	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);

	/*
	 * Display all mount option settings
	 */
834
	seq_puts(m, "\n\topts:\t");
835
	seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
836 837 838
	seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
	seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
	seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
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	nfs_show_mount_options(m, nfss, 1);

	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);

	show_implementation_id(m, nfss);

845
	seq_puts(m, "\n\tcaps:\t");
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	seq_printf(m, "caps=0x%x", nfss->caps);
	seq_printf(m, ",wtmult=%u", nfss->wtmult);
	seq_printf(m, ",dtsize=%u", nfss->dtsize);
	seq_printf(m, ",bsize=%u", nfss->bsize);
	seq_printf(m, ",namlen=%u", nfss->namelen);

#if IS_ENABLED(CONFIG_NFS_V4)
	if (nfss->nfs_client->rpc_ops->version == 4) {
854
		seq_puts(m, "\n\tnfsv4:\t");
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		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
		show_sessions(m, nfss);
		show_pnfs(m, nfss);
861
		show_lease(m, nfss);
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	}
#endif

	/*
	 * Display security flavor in effect for this mount
	 */
	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
	if (auth->au_flavor)
		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);

	/*
	 * Display superblock I/O counters
	 */
	for_each_possible_cpu(cpu) {
		struct nfs_iostats *stats;

		preempt_disable();
		stats = per_cpu_ptr(nfss->io_stats, cpu);

		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
			totals.events[i] += stats->events[i];
		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
			totals.bytes[i] += stats->bytes[i];
#ifdef CONFIG_NFS_FSCACHE
		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
			totals.fscache[i] += stats->fscache[i];
#endif

		preempt_enable();
	}

893
	seq_puts(m, "\n\tevents:\t");
894 895
	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
		seq_printf(m, "%lu ", totals.events[i]);
896
	seq_puts(m, "\n\tbytes:\t");
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	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
		seq_printf(m, "%Lu ", totals.bytes[i]);
#ifdef CONFIG_NFS_FSCACHE
	if (nfss->options & NFS_OPTION_FSCACHE) {
901
		seq_puts(m, "\n\tfsc:\t");
902
		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
903
			seq_printf(m, "%Lu ", totals.fscache[i]);
904 905
	}
#endif
906
	seq_putc(m, '\n');
907

908
	rpc_clnt_show_stats(m, nfss->client);
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	return 0;
}
EXPORT_SYMBOL_GPL(nfs_show_stats);

/*
 * Begin unmount by attempting to remove all automounted mountpoints we added
 * in response to xdev traversals and referrals
 */
void nfs_umount_begin(struct super_block *sb)
{
	struct nfs_server *server;
	struct rpc_clnt *rpc;

	server = NFS_SB(sb);
	/* -EIO all pending I/O */
	rpc = server->client_acl;
	if (!IS_ERR(rpc))
		rpc_killall_tasks(rpc);
	rpc = server->client;
	if (!IS_ERR(rpc))
		rpc_killall_tasks(rpc);
}
EXPORT_SYMBOL_GPL(nfs_umount_begin);

static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
{
	struct nfs_parsed_mount_data *data;

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (data) {
940 941
		data->timeo		= NFS_UNSPEC_TIMEO;
		data->retrans		= NFS_UNSPEC_RETRANS;
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		data->acregmin		= NFS_DEF_ACREGMIN;
		data->acregmax		= NFS_DEF_ACREGMAX;
		data->acdirmin		= NFS_DEF_ACDIRMIN;
		data->acdirmax		= NFS_DEF_ACDIRMAX;
		data->mount_server.port	= NFS_UNSPEC_PORT;
		data->nfs_server.port	= NFS_UNSPEC_PORT;
		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
		data->selected_flavor	= RPC_AUTH_MAXFLAVOR;
		data->minorversion	= 0;
		data->need_mount	= true;
		data->net		= current->nsproxy->net_ns;
953
		data->lsm_opts		= NULL;
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	}
	return data;
}

static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
{
	if (data) {
		kfree(data->client_address);
		kfree(data->mount_server.hostname);
		kfree(data->nfs_server.export_path);
		kfree(data->nfs_server.hostname);
		kfree(data->fscache_uniq);
		security_free_mnt_opts(&data->lsm_opts);
		kfree(data);
	}
}

/*
 * Sanity-check a server address provided by the mount command.
 *
 * Address family must be initialized, and address must not be
 * the ANY address for that family.
 */
static int nfs_verify_server_address(struct sockaddr *addr)
{
	switch (addr->sa_family) {
	case AF_INET: {
		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
	}
	case AF_INET6: {
		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
		return !ipv6_addr_any(sa);
	}
	}

	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
	return 0;
}

/*
 * Select between a default port value and a user-specified port value.
 * If a zero value is set, then autobind will be used.
 */
static void nfs_set_port(struct sockaddr *sap, int *port,
				 const unsigned short default_port)
{
	if (*port == NFS_UNSPEC_PORT)
		*port = default_port;

	rpc_set_port(sap, *port);
}

/*
 * Sanity check the NFS transport protocol.
 *
 */
static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
{
	switch (mnt->nfs_server.protocol) {
	case XPRT_TRANSPORT_UDP:
	case XPRT_TRANSPORT_TCP:
	case XPRT_TRANSPORT_RDMA:
		break;
	default:
		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
	}
}

/*
 * For text based NFSv2/v3 mounts, the mount protocol transport default
 * settings should depend upon the specified NFS transport.
 */
static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
{
	nfs_validate_transport_protocol(mnt);

	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
			return;
	switch (mnt->nfs_server.protocol) {
	case XPRT_TRANSPORT_UDP:
		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
		break;
	case XPRT_TRANSPORT_TCP:
	case XPRT_TRANSPORT_RDMA:
		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
	}
}

/*
 * Add 'flavor' to 'auth_info' if not already present.
 * Returns true if 'flavor' ends up in the list, false otherwise
 */
static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
			      rpc_authflavor_t flavor)
{
	unsigned int i;
	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);

	/* make sure this flavor isn't already in the list */
	for (i = 0; i < auth_info->flavor_len; i++) {
		if (flavor == auth_info->flavors[i])
			return true;
	}

	if (auth_info->flavor_len + 1 >= max_flavor_len) {
		dfprintk(MOUNT, "NFS: too many sec= flavors\n");
		return false;
	}

	auth_info->flavors[auth_info->flavor_len++] = flavor;
	return true;
}

/*
 * Return true if 'match' is in auth_info or auth_info is empty.
 * Return false otherwise.
 */
bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
			 rpc_authflavor_t match)
{
	int i;

	if (!auth_info->flavor_len)
		return true;

	for (i = 0; i < auth_info->flavor_len; i++) {
		if (auth_info->flavors[i] == match)
			return true;
	}
	return false;
}
EXPORT_SYMBOL_GPL(nfs_auth_info_match);

/*
 * Parse the value of the 'sec=' option.
 */
static int nfs_parse_security_flavors(char *value,
				      struct nfs_parsed_mount_data *mnt)
{
	substring_t args[MAX_OPT_ARGS];
	rpc_authflavor_t pseudoflavor;
	char *p;

	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);

	while ((p = strsep(&value, ":")) != NULL) {
		switch (match_token(p, nfs_secflavor_tokens, args)) {
		case Opt_sec_none:
			pseudoflavor = RPC_AUTH_NULL;
			break;
		case Opt_sec_sys:
			pseudoflavor = RPC_AUTH_UNIX;
			break;
		case Opt_sec_krb5:
			pseudoflavor = RPC_AUTH_GSS_KRB5;
			break;
		case Opt_sec_krb5i:
			pseudoflavor = RPC_AUTH_GSS_KRB5I;
			break;
		case Opt_sec_krb5p:
			pseudoflavor = RPC_AUTH_GSS_KRB5P;
			break;
		case Opt_sec_lkey:
			pseudoflavor = RPC_AUTH_GSS_LKEY;
			break;
		case Opt_sec_lkeyi:
			pseudoflavor = RPC_AUTH_GSS_LKEYI;
			break;
		case Opt_sec_lkeyp:
			pseudoflavor = RPC_AUTH_GSS_LKEYP;
			break;
		case Opt_sec_spkm:
			pseudoflavor = RPC_AUTH_GSS_SPKM;
			break;
		case Opt_sec_spkmi:
			pseudoflavor = RPC_AUTH_GSS_SPKMI;
			break;
		case Opt_sec_spkmp:
			pseudoflavor = RPC_AUTH_GSS_SPKMP;
			break;
		default:
			dfprintk(MOUNT,
				 "NFS: sec= option '%s' not recognized\n", p);
			return 0;
		}

		if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
			return 0;
	}

	return 1;
}

static int nfs_parse_version_string(char *string,
		struct nfs_parsed_mount_data *mnt,
		substring_t *args)
{
	mnt->flags &= ~NFS_MOUNT_VER3;
	switch (match_token(string, nfs_vers_tokens, args)) {
	case Opt_vers_2:
		mnt->version = 2;
		break;
	case Opt_vers_3:
		mnt->flags |= NFS_MOUNT_VER3;
		mnt->version = 3;
		break;
	case Opt_vers_4:
		/* Backward compatibility option. In future,
		 * the mount program should always supply
		 * a NFSv4 minor version number.
		 */
		mnt->version = 4;
		break;
	case Opt_vers_4_0:
		mnt->version = 4;
		mnt->minorversion = 0;
		break;
	case Opt_vers_4_1:
		mnt->version = 4;
		mnt->minorversion = 1;
		break;
	case Opt_vers_4_2:
		mnt->version = 4;
		mnt->minorversion = 2;
		break;
	default:
		return 0;
	}
	return 1;
}

static int nfs_get_option_str(substring_t args[], char **option)
{
	kfree(*option);
	*option = match_strdup(args);
	return !*option;
}

static int nfs_get_option_ul(substring_t args[], unsigned long *option)
{
	int rc;
	char *string;

	string = match_strdup(args);
	if (string == NULL)
		return -ENOMEM;
	rc = kstrtoul(string, 10, option);
	kfree(string);

	return rc;
}

1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220
static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
		unsigned long l_bound, unsigned long u_bound)
{
	int ret;

	ret = nfs_get_option_ul(args, option);
	if (ret != 0)
		return ret;
	if (*option < l_bound || *option > u_bound)
		return -ERANGE;
	return 0;
}

1221 1222 1223 1224 1225 1226 1227 1228 1229
/*
 * Error-check and convert a string of mount options from user space into
 * a data structure.  The whole mount string is processed; bad options are
 * skipped as they are encountered.  If there were no errors, return 1;
 * otherwise return 0 (zero).
 */
static int nfs_parse_mount_options(char *raw,
				   struct nfs_parsed_mount_data *mnt)
{
1230
	char *p, *string;
1231 1232 1233 1234 1235 1236 1237 1238 1239 1240
	int rc, sloppy = 0, invalid_option = 0;
	unsigned short protofamily = AF_UNSPEC;
	unsigned short mountfamily = AF_UNSPEC;

	if (!raw) {
		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
		return 1;
	}
	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);

1241
	rc = security_sb_eat_lsm_opts(raw, &mnt->lsm_opts);
1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262
	if (rc)
		goto out_security_failure;

	while ((p = strsep(&raw, ",")) != NULL) {
		substring_t args[MAX_OPT_ARGS];
		unsigned long option;
		int token;

		if (!*p)
			continue;

		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);

		token = match_token(p, nfs_mount_option_tokens, args);
		switch (token) {

		/*
		 * boolean options:  foo/nofoo
		 */
		case Opt_soft:
			mnt->flags |= NFS_MOUNT_SOFT;
1263
			mnt->flags &= ~NFS_MOUNT_SOFTERR;
1264
			break;
1265 1266
		case Opt_softerr:
			mnt->flags |= NFS_MOUNT_SOFTERR;
1267 1268
			mnt->flags &= ~NFS_MOUNT_SOFT;
			break;
1269 1270 1271
		case Opt_hard:
			mnt->flags &= ~(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR);
			break;
1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350
		case Opt_posix:
			mnt->flags |= NFS_MOUNT_POSIX;
			break;
		case Opt_noposix:
			mnt->flags &= ~NFS_MOUNT_POSIX;
			break;
		case Opt_cto:
			mnt->flags &= ~NFS_MOUNT_NOCTO;
			break;
		case Opt_nocto:
			mnt->flags |= NFS_MOUNT_NOCTO;
			break;
		case Opt_ac:
			mnt->flags &= ~NFS_MOUNT_NOAC;
			break;
		case Opt_noac:
			mnt->flags |= NFS_MOUNT_NOAC;
			break;
		case Opt_lock:
			mnt->flags &= ~NFS_MOUNT_NONLM;
			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
					NFS_MOUNT_LOCAL_FCNTL);
			break;
		case Opt_nolock:
			mnt->flags |= NFS_MOUNT_NONLM;
			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
				       NFS_MOUNT_LOCAL_FCNTL);
			break;
		case Opt_udp:
			mnt->flags &= ~NFS_MOUNT_TCP;
			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
			break;
		case Opt_tcp:
			mnt->flags |= NFS_MOUNT_TCP;
			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
			break;
		case Opt_rdma:
			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
			xprt_load_transport(p);
			break;
		case Opt_acl:
			mnt->flags &= ~NFS_MOUNT_NOACL;
			break;
		case Opt_noacl:
			mnt->flags |= NFS_MOUNT_NOACL;
			break;
		case Opt_rdirplus:
			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
			break;
		case Opt_nordirplus:
			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
			break;
		case Opt_sharecache:
			mnt->flags &= ~NFS_MOUNT_UNSHARED;
			break;
		case Opt_nosharecache:
			mnt->flags |= NFS_MOUNT_UNSHARED;
			break;
		case Opt_resvport:
			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
			break;
		case Opt_noresvport:
			mnt->flags |= NFS_MOUNT_NORESVPORT;
			break;
		case Opt_fscache:
			mnt->options |= NFS_OPTION_FSCACHE;
			kfree(mnt->fscache_uniq);
			mnt->fscache_uniq = NULL;
			break;
		case Opt_nofscache:
			mnt->options &= ~NFS_OPTION_FSCACHE;
			kfree(mnt->fscache_uniq);
			mnt->fscache_uniq = NULL;
			break;
		case Opt_migration:
			mnt->options |= NFS_OPTION_MIGRATION;
			break;
		case Opt_nomigration:
1351
			mnt->options &= ~NFS_OPTION_MIGRATION;
1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378
			break;

		/*
		 * options that take numeric values
		 */
		case Opt_port:
			if (nfs_get_option_ul(args, &option) ||
			    option > USHRT_MAX)
				goto out_invalid_value;
			mnt->nfs_server.port = option;
			break;
		case Opt_rsize:
			if (nfs_get_option_ul(args, &option))
				goto out_invalid_value;
			mnt->rsize = option;
			break;
		case Opt_wsize:
			if (nfs_get_option_ul(args, &option))
				goto out_invalid_value;
			mnt->wsize = option;
			break;
		case Opt_bsize:
			if (nfs_get_option_ul(args, &option))
				goto out_invalid_value;
			mnt->bsize = option;
			break;
		case Opt_timeo:
1379
			if (nfs_get_option_ul_bound(args, &option, 1, INT_MAX))
1380 1381 1382 1383
				goto out_invalid_value;
			mnt->timeo = option;
			break;
		case Opt_retrans:
1384
			if (nfs_get_option_ul_bound(args, &option, 0, INT_MAX))
1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474
				goto out_invalid_value;
			mnt->retrans = option;
			break;
		case Opt_acregmin:
			if (nfs_get_option_ul(args, &option))
				goto out_invalid_value;
			mnt->acregmin = option;
			break;
		case Opt_acregmax:
			if (nfs_get_option_ul(args, &option))
				goto out_invalid_value;
			mnt->acregmax = option;
			break;
		case Opt_acdirmin:
			if (nfs_get_option_ul(args, &option))
				goto out_invalid_value;
			mnt->acdirmin = option;
			break;
		case Opt_acdirmax:
			if (nfs_get_option_ul(args, &option))
				goto out_invalid_value;
			mnt->acdirmax = option;
			break;
		case Opt_actimeo:
			if (nfs_get_option_ul(args, &option))
				goto out_invalid_value;
			mnt->acregmin = mnt->acregmax =
			mnt->acdirmin = mnt->acdirmax = option;
			break;
		case Opt_namelen:
			if (nfs_get_option_ul(args, &option))
				goto out_invalid_value;
			mnt->namlen = option;
			break;
		case Opt_mountport:
			if (nfs_get_option_ul(args, &option) ||
			    option > USHRT_MAX)
				goto out_invalid_value;
			mnt->mount_server.port = option;
			break;
		case Opt_mountvers:
			if (nfs_get_option_ul(args, &option) ||
			    option < NFS_MNT_VERSION ||
			    option > NFS_MNT3_VERSION)
				goto out_invalid_value;
			mnt->mount_server.version = option;
			break;
		case Opt_minorversion:
			if (nfs_get_option_ul(args, &option))
				goto out_invalid_value;
			if (option > NFS4_MAX_MINOR_VERSION)
				goto out_invalid_value;
			mnt->minorversion = option;
			break;

		/*
		 * options that take text values
		 */
		case Opt_nfsvers:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;
			rc = nfs_parse_version_string(string, mnt, args);
			kfree(string);
			if (!rc)
				goto out_invalid_value;
			break;
		case Opt_sec:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;
			rc = nfs_parse_security_flavors(string, mnt);
			kfree(string);
			if (!rc) {
				dfprintk(MOUNT, "NFS:   unrecognized "
						"security flavor\n");
				return 0;
			}
			break;
		case Opt_proto:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;
			token = match_token(string,
					    nfs_xprt_protocol_tokens, args);

			protofamily = AF_INET;
			switch (token) {
			case Opt_xprt_udp6:
				protofamily = AF_INET6;
1475
				/* fall through */
1476 1477 1478 1479 1480 1481
			case Opt_xprt_udp:
				mnt->flags &= ~NFS_MOUNT_TCP;
				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
				break;
			case Opt_xprt_tcp6:
				protofamily = AF_INET6;
1482
				/* fall through */
1483 1484 1485 1486 1487 1488
			case Opt_xprt_tcp:
				mnt->flags |= NFS_MOUNT_TCP;
				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
				break;
			case Opt_xprt_rdma6:
				protofamily = AF_INET6;
1489
				/* fall through */
1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515
			case Opt_xprt_rdma:
				/* vector side protocols to TCP */
				mnt->flags |= NFS_MOUNT_TCP;
				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
				xprt_load_transport(string);
				break;
			default:
				dfprintk(MOUNT, "NFS:   unrecognized "
						"transport protocol\n");
				kfree(string);
				return 0;
			}
			kfree(string);
			break;
		case Opt_mountproto:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;
			token = match_token(string,
					    nfs_xprt_protocol_tokens, args);
			kfree(string);

			mountfamily = AF_INET;
			switch (token) {
			case Opt_xprt_udp6:
				mountfamily = AF_INET6;
1516
				/* fall through */
1517 1518 1519 1520 1521
			case Opt_xprt_udp:
				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
				break;
			case Opt_xprt_tcp6:
				mountfamily = AF_INET6;
1522
				/* fall through */
1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567
			case Opt_xprt_tcp:
				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
				break;
			case Opt_xprt_rdma: /* not used for side protocols */
			default:
				dfprintk(MOUNT, "NFS:   unrecognized "
						"transport protocol\n");
				return 0;
			}
			break;
		case Opt_addr:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;
			mnt->nfs_server.addrlen =
				rpc_pton(mnt->net, string, strlen(string),
					(struct sockaddr *)
					&mnt->nfs_server.address,
					sizeof(mnt->nfs_server.address));
			kfree(string);
			if (mnt->nfs_server.addrlen == 0)
				goto out_invalid_address;
			break;
		case Opt_clientaddr:
			if (nfs_get_option_str(args, &mnt->client_address))
				goto out_nomem;
			break;
		case Opt_mounthost:
			if (nfs_get_option_str(args,
					       &mnt->mount_server.hostname))
				goto out_nomem;
			break;
		case Opt_mountaddr:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;
			mnt->mount_server.addrlen =
				rpc_pton(mnt->net, string, strlen(string),
					(struct sockaddr *)
					&mnt->mount_server.address,
					sizeof(mnt->mount_server.address));
			kfree(string);
			if (mnt->mount_server.addrlen == 0)
				goto out_invalid_address;
			break;
1568 1569 1570 1571 1572
		case Opt_nconnect:
			if (nfs_get_option_ul_bound(args, &option, 1, NFS_MAX_CONNECTIONS))
				goto out_invalid_value;
			mnt->nfs_server.nconnect = option;
			break;
1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718
		case Opt_lookupcache:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;
			token = match_token(string,
					nfs_lookupcache_tokens, args);
			kfree(string);
			switch (token) {
				case Opt_lookupcache_all:
					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
					break;
				case Opt_lookupcache_positive:
					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
					break;
				case Opt_lookupcache_none:
					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
					break;
				default:
					dfprintk(MOUNT, "NFS:   invalid "
							"lookupcache argument\n");
					return 0;
			};
			break;
		case Opt_fscache_uniq:
			if (nfs_get_option_str(args, &mnt->fscache_uniq))
				goto out_nomem;
			mnt->options |= NFS_OPTION_FSCACHE;
			break;
		case Opt_local_lock:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;
			token = match_token(string, nfs_local_lock_tokens,
					args);
			kfree(string);
			switch (token) {
			case Opt_local_lock_all:
				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
					       NFS_MOUNT_LOCAL_FCNTL);
				break;
			case Opt_local_lock_flock:
				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
				break;
			case Opt_local_lock_posix:
				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
				break;
			case Opt_local_lock_none:
				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
						NFS_MOUNT_LOCAL_FCNTL);
				break;
			default:
				dfprintk(MOUNT, "NFS:	invalid	"
						"local_lock argument\n");
				return 0;
			};
			break;

		/*
		 * Special options
		 */
		case Opt_sloppy:
			sloppy = 1;
			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
			break;
		case Opt_userspace:
		case Opt_deprecated:
			dfprintk(MOUNT, "NFS:   ignoring mount option "
					"'%s'\n", p);
			break;

		default:
			invalid_option = 1;
			dfprintk(MOUNT, "NFS:   unrecognized mount option "
					"'%s'\n", p);
		}
	}

	if (!sloppy && invalid_option)
		return 0;

	if (mnt->minorversion && mnt->version != 4)
		goto out_minorversion_mismatch;

	if (mnt->options & NFS_OPTION_MIGRATION &&
	    (mnt->version != 4 || mnt->minorversion != 0))
		goto out_migration_misuse;

	/*
	 * verify that any proto=/mountproto= options match the address
	 * families in the addr=/mountaddr= options.
	 */
	if (protofamily != AF_UNSPEC &&
	    protofamily != mnt->nfs_server.address.ss_family)
		goto out_proto_mismatch;

	if (mountfamily != AF_UNSPEC) {
		if (mnt->mount_server.addrlen) {
			if (mountfamily != mnt->mount_server.address.ss_family)
				goto out_mountproto_mismatch;
		} else {
			if (mountfamily != mnt->nfs_server.address.ss_family)
				goto out_mountproto_mismatch;
		}
	}

	return 1;

out_mountproto_mismatch:
	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
			 "option\n");
	return 0;
out_proto_mismatch:
	printk(KERN_INFO "NFS: server address does not match proto= option\n");
	return 0;
out_invalid_address:
	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
	return 0;
out_invalid_value:
	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
	return 0;
out_minorversion_mismatch:
	printk(KERN_INFO "NFS: mount option vers=%u does not support "
			 "minorversion=%u\n", mnt->version, mnt->minorversion);
	return 0;
out_migration_misuse:
	printk(KERN_INFO
		"NFS: 'migration' not supported for this NFS version\n");
	return 0;
out_nomem:
	printk(KERN_INFO "NFS: not enough memory to parse option\n");
	return 0;
out_security_failure:
	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
	return 0;
}

/*
 * Ensure that a specified authtype in args->auth_info is supported by
 * the server. Returns 0 and sets args->selected_flavor if it's ok, and
 * -EACCES if not.
 */
static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
			rpc_authflavor_t *server_authlist, unsigned int count)
{
	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1719
	bool found_auth_null = false;
1720 1721 1722 1723 1724 1725 1726 1727
	unsigned int i;

	/*
	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
	 * must be in the list returned by the server.
	 *
	 * AUTH_NULL has a special meaning when it's in the server list - it
	 * means that the server will ignore the rpc creds, so any flavor
1728
	 * can be used but still use the sec= that was specified.
1729 1730 1731 1732
	 *
	 * Note also that the MNT procedure in MNTv1 does not return a list
	 * of supported security flavors. In this case, nfs_mount() fabricates
	 * a security flavor list containing just AUTH_NULL.
1733 1734 1735 1736
	 */
	for (i = 0; i < count; i++) {
		flavor = server_authlist[i];

1737
		if (nfs_auth_info_match(&args->auth_info, flavor))
1738
			goto out;
1739 1740

		if (flavor == RPC_AUTH_NULL)
1741
			found_auth_null = true;
1742 1743
	}

1744 1745
	if (found_auth_null) {
		flavor = args->auth_info.flavors[0];
1746
		goto out;
1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928
	}

	dfprintk(MOUNT,
		 "NFS: specified auth flavors not supported by server\n");
	return -EACCES;

out:
	args->selected_flavor = flavor;
	dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
	return 0;
}

/*
 * Use the remote server's MOUNT service to request the NFS file handle
 * corresponding to the provided path.
 */
static int nfs_request_mount(struct nfs_parsed_mount_data *args,
			     struct nfs_fh *root_fh,
			     rpc_authflavor_t *server_authlist,
			     unsigned int *server_authlist_len)
{
	struct nfs_mount_request request = {
		.sap		= (struct sockaddr *)
						&args->mount_server.address,
		.dirpath	= args->nfs_server.export_path,
		.protocol	= args->mount_server.protocol,
		.fh		= root_fh,
		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
		.auth_flav_len	= server_authlist_len,
		.auth_flavs	= server_authlist,
		.net		= args->net,
	};
	int status;

	if (args->mount_server.version == 0) {
		switch (args->version) {
			default:
				args->mount_server.version = NFS_MNT3_VERSION;
				break;
			case 2:
				args->mount_server.version = NFS_MNT_VERSION;
		}
	}
	request.version = args->mount_server.version;

	if (args->mount_server.hostname)
		request.hostname = args->mount_server.hostname;
	else
		request.hostname = args->nfs_server.hostname;

	/*
	 * Construct the mount server's address.
	 */
	if (args->mount_server.address.ss_family == AF_UNSPEC) {
		memcpy(request.sap, &args->nfs_server.address,
		       args->nfs_server.addrlen);
		args->mount_server.addrlen = args->nfs_server.addrlen;
	}
	request.salen = args->mount_server.addrlen;
	nfs_set_port(request.sap, &args->mount_server.port, 0);

	/*
	 * Now ask the mount server to map our export path
	 * to a file handle.
	 */
	status = nfs_mount(&request);
	if (status != 0) {
		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
				request.hostname, status);
		return status;
	}

	return 0;
}

static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
					struct nfs_subversion *nfs_mod)
{
	int status;
	unsigned int i;
	bool tried_auth_unix = false;
	bool auth_null_in_list = false;
	struct nfs_server *server = ERR_PTR(-EACCES);
	struct nfs_parsed_mount_data *args = mount_info->parsed;
	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
	unsigned int authlist_len = ARRAY_SIZE(authlist);

	status = nfs_request_mount(args, mount_info->mntfh, authlist,
					&authlist_len);
	if (status)
		return ERR_PTR(status);

	/*
	 * Was a sec= authflavor specified in the options? First, verify
	 * whether the server supports it, and then just try to use it if so.
	 */
	if (args->auth_info.flavor_len > 0) {
		status = nfs_verify_authflavors(args, authlist, authlist_len);
		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
			 args->selected_flavor);
		if (status)
			return ERR_PTR(status);
		return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
	}

	/*
	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
	 * SHOULD prefer the flavor listed first. However, some servers list
	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
	 */
	for (i = 0; i < authlist_len; ++i) {
		rpc_authflavor_t flavor;
		struct rpcsec_gss_info info;

		flavor = authlist[i];
		switch (flavor) {
		case RPC_AUTH_UNIX:
			tried_auth_unix = true;
			break;
		case RPC_AUTH_NULL:
			auth_null_in_list = true;
			continue;
		default:
			if (rpcauth_get_gssinfo(flavor, &info) != 0)
				continue;
			/* Fallthrough */
		}
		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
		args->selected_flavor = flavor;
		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
		if (!IS_ERR(server))
			return server;
	}

	/*
	 * Nothing we tried so far worked. At this point, give up if we've
	 * already tried AUTH_UNIX or if the server's list doesn't contain
	 * AUTH_NULL
	 */
	if (tried_auth_unix || !auth_null_in_list)
		return server;

	/* Last chance! Try AUTH_UNIX */
	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
	args->selected_flavor = RPC_AUTH_UNIX;
	return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
}

struct dentry *nfs_try_mount(int flags, const char *dev_name,
			     struct nfs_mount_info *mount_info,
			     struct nfs_subversion *nfs_mod)
{
	struct nfs_server *server;

	if (mount_info->parsed->need_mount)
		server = nfs_try_mount_request(mount_info, nfs_mod);
	else
		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);

	if (IS_ERR(server))
		return ERR_CAST(server);

	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
}
EXPORT_SYMBOL_GPL(nfs_try_mount);

/*
 * Split "dev_name" into "hostname:export_path".
 *
 * The leftmost colon demarks the split between the server's hostname
 * and the export path.  If the hostname starts with a left square
 * bracket, then it may contain colons.
 *
 * Note: caller frees hostname and export path, even on error.
 */
static int nfs_parse_devname(const char *dev_name,
			     char **hostname, size_t maxnamlen,
			     char **export_path, size_t maxpathlen)
{
	size_t len;
	char *end;

1929 1930 1931 1932 1933
	if (unlikely(!dev_name || !*dev_name)) {
		dfprintk(MOUNT, "NFS: device name not specified\n");
		return -EINVAL;
	}

1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952
	/* Is the host name protected with square brakcets? */
	if (*dev_name == '[') {
		end = strchr(++dev_name, ']');
		if (end == NULL || end[1] != ':')
			goto out_bad_devname;

		len = end - dev_name;
		end++;
	} else {
		char *comma;

		end = strchr(dev_name, ':');
		if (end == NULL)
			goto out_bad_devname;
		len = end - dev_name;

		/* kill possible hostname list: not supported */
		comma = strchr(dev_name, ',');
		if (comma != NULL && comma < end)
1953
			len = comma - dev_name;
1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
	}

	if (len > maxnamlen)
		goto out_hostname;

	/* N.B. caller will free nfs_server.hostname in all cases */
	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
	if (*hostname == NULL)
		goto out_nomem;
	len = strlen(++end);
	if (len > maxpathlen)
		goto out_path;
	*export_path = kstrndup(end, len, GFP_KERNEL);
	if (!*export_path)
		goto out_nomem;

	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
	return 0;

out_bad_devname:
	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
	return -EINVAL;

out_nomem:
	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
	return -ENOMEM;

out_hostname:
	dfprintk(MOUNT, "NFS: server hostname too long\n");
	return -ENAMETOOLONG;

out_path:
	dfprintk(MOUNT, "NFS: export pathname too long\n");
	return -ENAMETOOLONG;
}

/*
 * Validate the NFS2/NFS3 mount data
 * - fills in the mount root filehandle
 *
 * For option strings, user space handles the following behaviors:
 *
 * + DNS: mapping server host name to IP address ("addr=" option)
 *
 * + failure mode: how to behave if a mount request can't be handled
 *   immediately ("fg/bg" option)
 *
 * + retry: how often to retry a mount request ("retry=" option)
 *
 * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
 *   mountproto=tcp after mountproto=udp, and so on
 */
static int nfs23_validate_mount_data(void *options,
				     struct nfs_parsed_mount_data *args,
				     struct nfs_fh *mntfh,
				     const char *dev_name)
{
	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;

	if (data == NULL)
		goto out_no_data;

	args->version = NFS_DEFAULT_VERSION;
	switch (data->version) {
	case 1:
2021
		data->namlen = 0; /* fall through */
2022
	case 2:
2023
		data->bsize = 0; /* fall through */
2024 2025 2026 2027 2028 2029 2030
	case 3:
		if (data->flags & NFS_MOUNT_VER3)
			goto out_no_v3;
		data->root.size = NFS2_FHSIZE;
		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
		/* Turn off security negotiation */
		extra_flags |= NFS_MOUNT_SECFLAVOUR;
2031
		/* fall through */
2032 2033 2034
	case 4:
		if (data->flags & NFS_MOUNT_SECFLAVOUR)
			goto out_no_sec;
2035
		/* fall through */
2036 2037
	case 5:
		memset(data->context, 0, sizeof(data->context));
2038
		/* fall through */
2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074
	case 6:
		if (data->flags & NFS_MOUNT_VER3) {
			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
				goto out_invalid_fh;
			mntfh->size = data->root.size;
			args->version = 3;
		} else {
			mntfh->size = NFS2_FHSIZE;
			args->version = 2;
		}


		memcpy(mntfh->data, data->root.data, mntfh->size);
		if (mntfh->size < sizeof(mntfh->data))
			memset(mntfh->data + mntfh->size, 0,
			       sizeof(mntfh->data) - mntfh->size);

		/*
		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
		 * can deal with.
		 */
		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
		args->flags		|= extra_flags;
		args->rsize		= data->rsize;
		args->wsize		= data->wsize;
		args->timeo		= data->timeo;
		args->retrans		= data->retrans;
		args->acregmin		= data->acregmin;
		args->acregmax		= data->acregmax;
		args->acdirmin		= data->acdirmin;
		args->acdirmax		= data->acdirmax;
		args->need_mount	= false;

		memcpy(sap, &data->addr, sizeof(data->addr));
		args->nfs_server.addrlen = sizeof(data->addr);
		args->nfs_server.port = ntohs(data->addr.sin_port);
2075 2076
		if (sap->sa_family != AF_INET ||
		    !nfs_verify_server_address(sap))
2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110
			goto out_no_address;

		if (!(data->flags & NFS_MOUNT_TCP))
			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
		/* N.B. caller will free nfs_server.hostname in all cases */
		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
		args->namlen		= data->namlen;
		args->bsize		= data->bsize;

		if (data->flags & NFS_MOUNT_SECFLAVOUR)
			args->selected_flavor = data->pseudoflavor;
		else
			args->selected_flavor = RPC_AUTH_UNIX;
		if (!args->nfs_server.hostname)
			goto out_nomem;

		if (!(data->flags & NFS_MOUNT_NONLM))
			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
					 NFS_MOUNT_LOCAL_FCNTL);
		else
			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
					NFS_MOUNT_LOCAL_FCNTL);
		/*
		 * The legacy version 6 binary mount data from userspace has a
		 * field used only to transport selinux information into the
		 * the kernel.  To continue to support that functionality we
		 * have a touch of selinux knowledge here in the NFS code. The
		 * userspace code converted context=blah to just blah so we are
		 * converting back to the full string selinux understands.
		 */
		if (data->context[0]){
#ifdef CONFIG_SECURITY_SELINUX
			int rc;
			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2111 2112
			rc = security_add_mnt_opt("context", data->context,
					strlen(data->context), &args->lsm_opts);
2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191
			if (rc)
				return rc;
#else
			return -EINVAL;
#endif
		}

		break;
	default:
		return NFS_TEXT_DATA;
	}

	return 0;

out_no_data:
	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
	return -EINVAL;

out_no_v3:
	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
		 data->version);
	return -EINVAL;

out_no_sec:
	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
	return -EINVAL;

out_nomem:
	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
	return -ENOMEM;

out_no_address:
	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
	return -EINVAL;

out_invalid_fh:
	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
	return -EINVAL;
}

#if IS_ENABLED(CONFIG_NFS_V4)
static int nfs_validate_mount_data(struct file_system_type *fs_type,
				   void *options,
				   struct nfs_parsed_mount_data *args,
				   struct nfs_fh *mntfh,
				   const char *dev_name)
{
	if (fs_type == &nfs_fs_type)
		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
	return nfs4_validate_mount_data(options, args, dev_name);
}
#else
static int nfs_validate_mount_data(struct file_system_type *fs_type,
				   void *options,
				   struct nfs_parsed_mount_data *args,
				   struct nfs_fh *mntfh,
				   const char *dev_name)
{
	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
}
#endif

static int nfs_validate_text_mount_data(void *options,
					struct nfs_parsed_mount_data *args,
					const char *dev_name)
{
	int port = 0;
	int max_namelen = PAGE_SIZE;
	int max_pathlen = NFS_MAXPATHLEN;
	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;

	if (nfs_parse_mount_options((char *)options, args) == 0)
		return -EINVAL;

	if (!nfs_verify_server_address(sap))
		goto out_no_address;

	if (args->version == 4) {
#if IS_ENABLED(CONFIG_NFS_V4)
2192 2193 2194 2195
		if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
			port = NFS_RDMA_PORT;
		else
			port = NFS_PORT;
2196 2197 2198 2199 2200 2201 2202 2203 2204
		max_namelen = NFS4_MAXNAMLEN;
		max_pathlen = NFS4_MAXPATHLEN;
		nfs_validate_transport_protocol(args);
		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
			goto out_invalid_transport_udp;
		nfs4_validate_mount_flags(args);
#else
		goto out_v4_not_compiled;
#endif /* CONFIG_NFS_V4 */
2205
	} else {
2206
		nfs_set_mount_transport_protocol(args);
2207 2208 2209
		if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
			port = NFS_RDMA_PORT;
	}
2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262

	nfs_set_port(sap, &args->nfs_server.port, port);

	return nfs_parse_devname(dev_name,
				   &args->nfs_server.hostname,
				   max_namelen,
				   &args->nfs_server.export_path,
				   max_pathlen);

#if !IS_ENABLED(CONFIG_NFS_V4)
out_v4_not_compiled:
	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
	return -EPROTONOSUPPORT;
#else
out_invalid_transport_udp:
	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
	return -EINVAL;
#endif /* !CONFIG_NFS_V4 */

out_no_address:
	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
	return -EINVAL;
}

#define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
		| NFS_MOUNT_SECURE \
		| NFS_MOUNT_TCP \
		| NFS_MOUNT_VER3 \
		| NFS_MOUNT_KERBEROS \
		| NFS_MOUNT_NONLM \
		| NFS_MOUNT_BROKEN_SUID \
		| NFS_MOUNT_STRICTLOCK \
		| NFS_MOUNT_LEGACY_INTERFACE)

#define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))

static int
nfs_compare_remount_data(struct nfs_server *nfss,
			 struct nfs_parsed_mount_data *data)
{
	if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
	    data->rsize != nfss->rsize ||
	    data->wsize != nfss->wsize ||
	    data->version != nfss->nfs_client->rpc_ops->version ||
	    data->minorversion != nfss->nfs_client->cl_minorversion ||
	    data->retrans != nfss->client->cl_timeout->to_retries ||
	    !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
	    data->acregmin != nfss->acregmin / HZ ||
	    data->acregmax != nfss->acregmax / HZ ||
	    data->acdirmin != nfss->acdirmin / HZ ||
	    data->acdirmax != nfss->acdirmax / HZ ||
	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2263
	    (data->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) ||
2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295
	    data->nfs_server.port != nfss->port ||
	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
		return -EINVAL;

	return 0;
}

int
nfs_remount(struct super_block *sb, int *flags, char *raw_data)
{
	int error;
	struct nfs_server *nfss = sb->s_fs_info;
	struct nfs_parsed_mount_data *data;
	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
	u32 nfsvers = nfss->nfs_client->rpc_ops->version;

	sync_filesystem(sb);

	/*
	 * Userspace mount programs that send binary options generally send
	 * them populated with default values. We have no way to know which
	 * ones were explicitly specified. Fall back to legacy behavior and
	 * just return success.
	 */
	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
					   options->version <= 6))))
		return 0;

2296
	data = nfs_alloc_parsed_mount_data();
2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326
	if (data == NULL)
		return -ENOMEM;

	/* fill out struct with values from existing mount */
	data->flags = nfss->flags;
	data->rsize = nfss->rsize;
	data->wsize = nfss->wsize;
	data->retrans = nfss->client->cl_timeout->to_retries;
	data->selected_flavor = nfss->client->cl_auth->au_flavor;
	data->acregmin = nfss->acregmin / HZ;
	data->acregmax = nfss->acregmax / HZ;
	data->acdirmin = nfss->acdirmin / HZ;
	data->acdirmax = nfss->acdirmax / HZ;
	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
	data->nfs_server.port = nfss->port;
	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
	data->version = nfsvers;
	data->minorversion = nfss->nfs_client->cl_minorversion;
	data->net = current->nsproxy->net_ns;
	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
		data->nfs_server.addrlen);

	/* overwrite those values with any that were specified */
	error = -EINVAL;
	if (!nfs_parse_mount_options((char *)options, data))
		goto out;

	/*
	 * noac is a special case. It implies -o sync, but that's not
	 * necessarily reflected in the mtab options. do_remount_sb
2327
	 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
2328 2329 2330
	 * remount options, so we have to explicitly reset it.
	 */
	if (data->flags & NFS_MOUNT_NOAC)
2331
		*flags |= SB_SYNCHRONOUS;
2332 2333 2334

	/* compare new mount options with old ones */
	error = nfs_compare_remount_data(nfss, data);
2335 2336
	if (!error)
		error = security_sb_remount(sb, data->lsm_opts);
2337
out:
2338
	nfs_free_parsed_mount_data(data);
2339 2340 2341 2342 2343 2344 2345
	return error;
}
EXPORT_SYMBOL_GPL(nfs_remount);

/*
 * Initialise the common bits of the superblock
 */
2346
static void nfs_initialise_sb(struct super_block *sb)
2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381
{
	struct nfs_server *server = NFS_SB(sb);

	sb->s_magic = NFS_SUPER_MAGIC;

	/* We probably want something more informative here */
	snprintf(sb->s_id, sizeof(sb->s_id),
		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));

	if (sb->s_blocksize == 0)
		sb->s_blocksize = nfs_block_bits(server->wsize,
						 &sb->s_blocksize_bits);

	nfs_super_set_maxbytes(sb, server->maxfilesize);
}

/*
 * Finish setting up an NFS2/3 superblock
 */
void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
{
	struct nfs_parsed_mount_data *data = mount_info->parsed;
	struct nfs_server *server = NFS_SB(sb);

	sb->s_blocksize_bits = 0;
	sb->s_blocksize = 0;
	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
	if (data && data->bsize)
		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);

	if (server->nfs_client->rpc_ops->version != 2) {
		/* The VFS shouldn't apply the umask to mode bits. We will do
		 * so ourselves when necessary.
		 */
2382
		sb->s_flags |= SB_POSIXACL;
2383
		sb->s_time_gran = 1;
2384
		sb->s_export_op = &nfs_export_ops;
2385 2386 2387 2388 2389 2390 2391 2392 2393
	}

 	nfs_initialise_sb(sb);
}
EXPORT_SYMBOL_GPL(nfs_fill_super);

/*
 * Finish setting up a cloned NFS2/3/4 superblock
 */
2394 2395
static void nfs_clone_super(struct super_block *sb,
			    struct nfs_mount_info *mount_info)
2396 2397 2398 2399 2400 2401 2402 2403 2404 2405
{
	const struct super_block *old_sb = mount_info->cloned->sb;
	struct nfs_server *server = NFS_SB(sb);

	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
	sb->s_blocksize = old_sb->s_blocksize;
	sb->s_maxbytes = old_sb->s_maxbytes;
	sb->s_xattr = old_sb->s_xattr;
	sb->s_op = old_sb->s_op;
	sb->s_time_gran = 1;
2406
	sb->s_export_op = old_sb->s_export_op;
2407 2408 2409 2410 2411

	if (server->nfs_client->rpc_ops->version != 2) {
		/* The VFS shouldn't apply the umask to mode bits. We will do
		 * so ourselves when necessary.
		 */
2412
		sb->s_flags |= SB_POSIXACL;
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	}

 	nfs_initialise_sb(sb);
}

static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
{
	const struct nfs_server *a = s->s_fs_info;
	const struct rpc_clnt *clnt_a = a->client;
	const struct rpc_clnt *clnt_b = b->client;

	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
		goto Ebusy;
	if (a->nfs_client != b->nfs_client)
		goto Ebusy;
	if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
		goto Ebusy;
	if (a->wsize != b->wsize)
		goto Ebusy;
	if (a->rsize != b->rsize)
		goto Ebusy;
	if (a->acregmin != b->acregmin)
		goto Ebusy;
	if (a->acregmax != b->acregmax)
		goto Ebusy;
	if (a->acdirmin != b->acdirmin)
		goto Ebusy;
	if (a->acdirmax != b->acdirmax)
		goto Ebusy;
2442
	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510
		goto Ebusy;
	return 1;
Ebusy:
	return 0;
}

struct nfs_sb_mountdata {
	struct nfs_server *server;
	int mntflags;
};

static int nfs_set_super(struct super_block *s, void *data)
{
	struct nfs_sb_mountdata *sb_mntdata = data;
	struct nfs_server *server = sb_mntdata->server;
	int ret;

	s->s_flags = sb_mntdata->mntflags;
	s->s_fs_info = server;
	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
	ret = set_anon_super(s, server);
	if (ret == 0)
		server->s_dev = s->s_dev;
	return ret;
}

static int nfs_compare_super_address(struct nfs_server *server1,
				     struct nfs_server *server2)
{
	struct sockaddr *sap1, *sap2;
	struct rpc_xprt *xprt1 = server1->client->cl_xprt;
	struct rpc_xprt *xprt2 = server2->client->cl_xprt;

	if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
		return 0;

	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;

	if (sap1->sa_family != sap2->sa_family)
		return 0;

	switch (sap1->sa_family) {
	case AF_INET: {
		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
			return 0;
		if (sin1->sin_port != sin2->sin_port)
			return 0;
		break;
	}
	case AF_INET6: {
		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
			return 0;
		if (sin1->sin6_port != sin2->sin6_port)
			return 0;
		break;
	}
	default:
		return 0;
	}

	return 1;
}

2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525
static int nfs_compare_userns(const struct nfs_server *old,
		const struct nfs_server *new)
{
	const struct user_namespace *oldns = &init_user_ns;
	const struct user_namespace *newns = &init_user_ns;

	if (old->client && old->client->cl_cred)
		oldns = old->client->cl_cred->user_ns;
	if (new->client && new->client->cl_cred)
		newns = new->client->cl_cred->user_ns;
	if (oldns != newns)
		return 0;
	return 1;
}

2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538
static int nfs_compare_super(struct super_block *sb, void *data)
{
	struct nfs_sb_mountdata *sb_mntdata = data;
	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
	int mntflags = sb_mntdata->mntflags;

	if (!nfs_compare_super_address(old, server))
		return 0;
	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
	if (old->flags & NFS_MOUNT_UNSHARED)
		return 0;
	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
		return 0;
2539 2540
	if (!nfs_compare_userns(old, server))
		return 0;
2541 2542 2543 2544 2545 2546 2547 2548 2549 2550