blob: 3ee85c4e65d86b49a80ee41bd680289cf319effe [file] [log] [blame]
/*
* linux/fs/nfs/super.c
*
* Copyright (C) 1992 Rick Sladkey
*
* nfs superblock handling functions
*
* Modularised by Alan Cox <Alan.Cox@linux.org>, 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>
*
*/
#include <linux/config.h>
#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/stats.h>
#include <linux/sunrpc/metrics.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/nfs4_mount.h>
#include <linux/lockd/bind.h>
#include <linux/smp_lock.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/nfs_xdr.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"
#include "iostat.h"
#include "internal.h"
#define NFSDBG_FACILITY NFSDBG_VFS
/* Maximum number of readahead requests
* FIXME: this should really be a sysctl so that users may tune it to suit
* their needs. People that do NFS over a slow network, might for
* instance want to reduce it to something closer to 1 for improved
* interactive response.
*/
#define NFS_MAX_READAHEAD (RPC_DEF_SLOT_TABLE - 1)
/*
* RPC cruft for NFS
*/
static struct rpc_version * nfs_version[] = {
NULL,
NULL,
&nfs_version2,
#if defined(CONFIG_NFS_V3)
&nfs_version3,
#elif defined(CONFIG_NFS_V4)
NULL,
#endif
#if defined(CONFIG_NFS_V4)
&nfs_version4,
#endif
};
static 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 */
static void nfs_umount_begin(struct vfsmount *, int);
static int nfs_statfs(struct dentry *, struct kstatfs *);
static int nfs_show_options(struct seq_file *, struct vfsmount *);
static int nfs_show_stats(struct seq_file *, struct vfsmount *);
static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
static int nfs_clone_nfs_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
static void nfs_kill_super(struct super_block *);
static struct file_system_type nfs_fs_type = {
.owner = THIS_MODULE,
.name = "nfs",
.get_sb = nfs_get_sb,
.kill_sb = nfs_kill_super,
.fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};
struct file_system_type clone_nfs_fs_type = {
.owner = THIS_MODULE,
.name = "nfs",
.get_sb = nfs_clone_nfs_sb,
.kill_sb = nfs_kill_super,
.fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};
static struct super_operations nfs_sops = {
.alloc_inode = nfs_alloc_inode,
.destroy_inode = nfs_destroy_inode,
.write_inode = nfs_write_inode,
.statfs = nfs_statfs,
.clear_inode = nfs_clear_inode,
.umount_begin = nfs_umount_begin,
.show_options = nfs_show_options,
.show_stats = nfs_show_stats,
};
#ifdef CONFIG_NFS_V4
static int nfs4_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
static int nfs_clone_nfs4_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
static int nfs_referral_nfs4_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
static void nfs4_kill_super(struct super_block *sb);
static struct file_system_type nfs4_fs_type = {
.owner = THIS_MODULE,
.name = "nfs4",
.get_sb = nfs4_get_sb,
.kill_sb = nfs4_kill_super,
.fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};
struct file_system_type clone_nfs4_fs_type = {
.owner = THIS_MODULE,
.name = "nfs4",
.get_sb = nfs_clone_nfs4_sb,
.kill_sb = nfs4_kill_super,
.fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};
struct file_system_type nfs_referral_nfs4_fs_type = {
.owner = THIS_MODULE,
.name = "nfs4",
.get_sb = nfs_referral_nfs4_sb,
.kill_sb = nfs4_kill_super,
.fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};
static struct super_operations nfs4_sops = {
.alloc_inode = nfs_alloc_inode,
.destroy_inode = nfs_destroy_inode,
.write_inode = nfs_write_inode,
.statfs = nfs_statfs,
.clear_inode = nfs4_clear_inode,
.umount_begin = nfs_umount_begin,
.show_options = nfs_show_options,
.show_stats = nfs_show_stats,
};
#endif
static struct shrinker *acl_shrinker;
/*
* Register the NFS filesystems
*/
int __init register_nfs_fs(void)
{
int ret;
ret = register_filesystem(&nfs_fs_type);
if (ret < 0)
goto error_0;
#ifdef CONFIG_NFS_V4
ret = nfs_register_sysctl();
if (ret < 0)
goto error_1;
ret = register_filesystem(&nfs4_fs_type);
if (ret < 0)
goto error_2;
#endif
acl_shrinker = set_shrinker(DEFAULT_SEEKS, nfs_access_cache_shrinker);
return 0;
#ifdef CONFIG_NFS_V4
error_2:
nfs_unregister_sysctl();
error_1:
unregister_filesystem(&nfs_fs_type);
#endif
error_0:
return ret;
}
/*
* Unregister the NFS filesystems
*/
void __exit unregister_nfs_fs(void)
{
if (acl_shrinker != NULL)
remove_shrinker(acl_shrinker);
#ifdef CONFIG_NFS_V4
unregister_filesystem(&nfs4_fs_type);
nfs_unregister_sysctl();
#endif
unregister_filesystem(&nfs_fs_type);
}
/*
* Deliver file system statistics to userspace
*/
static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct nfs_server *server = NFS_SB(sb);
unsigned char blockbits;
unsigned long blockres;
struct nfs_fh *rootfh = NFS_FH(sb->s_root->d_inode);
struct nfs_fattr fattr;
struct nfs_fsstat res = {
.fattr = &fattr,
};
int error;
lock_kernel();
error = server->rpc_ops->statfs(server, rootfh, &res);
buf->f_type = NFS_SUPER_MAGIC;
if (error < 0)
goto out_err;
/*
* 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 = 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 = sb->s_blocksize;
blockbits = 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;
out:
unlock_kernel();
return 0;
out_err:
dprintk("%s: statfs error = %d\n", __FUNCTION__, -error);
buf->f_bsize = buf->f_blocks = buf->f_bfree = buf->f_bavail = -1;
goto out;
}
/*
* 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[] = {
{ 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" },
{ -1, "unknown" }
};
int i;
for (i=0; sec_flavours[i].flavour != -1; i++) {
if (sec_flavours[i].flavour == flavour)
break;
}
return sec_flavours[i].str;
}
/*
* 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 struct proc_nfs_info {
int flag;
char *str;
char *nostr;
} nfs_info[] = {
{ NFS_MOUNT_SOFT, ",soft", ",hard" },
{ NFS_MOUNT_INTR, ",intr", "" },
{ NFS_MOUNT_NOCTO, ",nocto", "" },
{ NFS_MOUNT_NOAC, ",noac", "" },
{ NFS_MOUNT_NONLM, ",nolock", "" },
{ NFS_MOUNT_NOACL, ",noacl", "" },
{ 0, NULL, NULL }
};
struct proc_nfs_info *nfs_infop;
char buf[12];
char *proto;
seq_printf(m, ",vers=%d", nfss->rpc_ops->version);
seq_printf(m, ",rsize=%d", nfss->rsize);
seq_printf(m, ",wsize=%d", nfss->wsize);
if (nfss->acregmin != 3*HZ || showdefaults)
seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
if (nfss->acregmax != 60*HZ || showdefaults)
seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
if (nfss->acdirmin != 30*HZ || showdefaults)
seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
if (nfss->acdirmax != 60*HZ || showdefaults)
seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
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);
}
switch (nfss->client->cl_xprt->prot) {
case IPPROTO_TCP:
proto = "tcp";
break;
case IPPROTO_UDP:
proto = "udp";
break;
default:
snprintf(buf, sizeof(buf), "%u", nfss->client->cl_xprt->prot);
proto = buf;
}
seq_printf(m, ",proto=%s", proto);
seq_printf(m, ",timeo=%lu", 10U * nfss->retrans_timeo / HZ);
seq_printf(m, ",retrans=%u", nfss->retrans_count);
seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
}
/*
* Describe the mount options on this VFS mountpoint
*/
static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
{
struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
nfs_show_mount_options(m, nfss, 0);
seq_puts(m, ",addr=");
seq_escape(m, nfss->hostname, " \t\n\\");
return 0;
}
/*
* Present statistical information for this VFS mountpoint
*/
static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
{
int i, cpu;
struct nfs_server *nfss = NFS_SB(mnt->mnt_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
*/
seq_printf(m, "\n\topts:\t");
seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
nfs_show_mount_options(m, nfss, 1);
seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
seq_printf(m, "\n\tcaps:\t");
seq_printf(m, "caps=0x%x", nfss->caps);
seq_printf(m, ",wtmult=%d", nfss->wtmult);
seq_printf(m, ",dtsize=%d", nfss->dtsize);
seq_printf(m, ",bsize=%d", nfss->bsize);
seq_printf(m, ",namelen=%d", nfss->namelen);
#ifdef CONFIG_NFS_V4
if (nfss->rpc_ops->version == 4) {
seq_printf(m, "\n\tnfsv4:\t");
seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
}
#endif
/*
* Display security flavor in effect for this mount
*/
seq_printf(m, "\n\tsec:\tflavor=%d", auth->au_ops->au_flavor);
if (auth->au_flavor)
seq_printf(m, ",pseudoflavor=%d", 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];
preempt_enable();
}
seq_printf(m, "\n\tevents:\t");
for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
seq_printf(m, "%lu ", totals.events[i]);
seq_printf(m, "\n\tbytes:\t");
for (i = 0; i < __NFSIOS_BYTESMAX; i++)
seq_printf(m, "%Lu ", totals.bytes[i]);
seq_printf(m, "\n");
rpc_print_iostats(m, nfss->client);
return 0;
}
/*
* Begin unmount by attempting to remove all automounted mountpoints we added
* in response to traversals
*/
static void nfs_umount_begin(struct vfsmount *vfsmnt, int flags)
{
struct nfs_server *server;
struct rpc_clnt *rpc;
shrink_submounts(vfsmnt, &nfs_automount_list);
if (!(flags & MNT_FORCE))
return;
/* -EIO all pending I/O */
server = NFS_SB(vfsmnt->mnt_sb);
rpc = server->client;
if (!IS_ERR(rpc))
rpc_killall_tasks(rpc);
rpc = server->client_acl;
if (!IS_ERR(rpc))
rpc_killall_tasks(rpc);
}
/*
* Obtain the root inode of the file system.
*/
static struct inode *
nfs_get_root(struct super_block *sb, struct nfs_fh *rootfh, struct nfs_fsinfo *fsinfo)
{
struct nfs_server *server = NFS_SB(sb);
int error;
error = server->rpc_ops->getroot(server, rootfh, fsinfo);
if (error < 0) {
dprintk("nfs_get_root: getattr error = %d\n", -error);
return ERR_PTR(error);
}
server->fsid = fsinfo->fattr->fsid;
return nfs_fhget(sb, rootfh, fsinfo->fattr);
}
/*
* Do NFS version-independent mount processing, and sanity checking
*/
static int
nfs_sb_init(struct super_block *sb, rpc_authflavor_t authflavor)
{
struct nfs_server *server;
struct inode *root_inode;
struct nfs_fattr fattr;
struct nfs_fsinfo fsinfo = {
.fattr = &fattr,
};
struct nfs_pathconf pathinfo = {
.fattr = &fattr,
};
int no_root_error = 0;
unsigned long max_rpc_payload;
/* We probably want something more informative here */
snprintf(sb->s_id, sizeof(sb->s_id), "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
server = NFS_SB(sb);
sb->s_magic = NFS_SUPER_MAGIC;
server->io_stats = nfs_alloc_iostats();
if (server->io_stats == NULL)
return -ENOMEM;
root_inode = nfs_get_root(sb, &server->fh, &fsinfo);
/* Did getting the root inode fail? */
if (IS_ERR(root_inode)) {
no_root_error = PTR_ERR(root_inode);
goto out_no_root;
}
sb->s_root = d_alloc_root(root_inode);
if (!sb->s_root) {
no_root_error = -ENOMEM;
goto out_no_root;
}
sb->s_root->d_op = server->rpc_ops->dentry_ops;
/* mount time stamp, in seconds */
server->mount_time = jiffies;
/* Get some general file system info */
if (server->namelen == 0 &&
server->rpc_ops->pathconf(server, &server->fh, &pathinfo) >= 0)
server->namelen = pathinfo.max_namelen;
/* Work out a lot of parameters */
if (server->rsize == 0)
server->rsize = nfs_block_size(fsinfo.rtpref, NULL);
if (server->wsize == 0)
server->wsize = nfs_block_size(fsinfo.wtpref, NULL);
if (fsinfo.rtmax >= 512 && server->rsize > fsinfo.rtmax)
server->rsize = nfs_block_size(fsinfo.rtmax, NULL);
if (fsinfo.wtmax >= 512 && server->wsize > fsinfo.wtmax)
server->wsize = nfs_block_size(fsinfo.wtmax, NULL);
max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
if (server->rsize > max_rpc_payload)
server->rsize = max_rpc_payload;
if (server->rsize > NFS_MAX_FILE_IO_SIZE)
server->rsize = NFS_MAX_FILE_IO_SIZE;
server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
if (server->wsize > max_rpc_payload)
server->wsize = max_rpc_payload;
if (server->wsize > NFS_MAX_FILE_IO_SIZE)
server->wsize = NFS_MAX_FILE_IO_SIZE;
server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
if (sb->s_blocksize == 0)
sb->s_blocksize = nfs_block_bits(server->wsize,
&sb->s_blocksize_bits);
server->wtmult = nfs_block_bits(fsinfo.wtmult, NULL);
server->dtsize = nfs_block_size(fsinfo.dtpref, NULL);
if (server->dtsize > PAGE_CACHE_SIZE)
server->dtsize = PAGE_CACHE_SIZE;
if (server->dtsize > server->rsize)
server->dtsize = server->rsize;
if (server->flags & NFS_MOUNT_NOAC) {
server->acregmin = server->acregmax = 0;
server->acdirmin = server->acdirmax = 0;
sb->s_flags |= MS_SYNCHRONOUS;
}
server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
nfs_super_set_maxbytes(sb, fsinfo.maxfilesize);
server->client->cl_intr = (server->flags & NFS_MOUNT_INTR) ? 1 : 0;
server->client->cl_softrtry = (server->flags & NFS_MOUNT_SOFT) ? 1 : 0;
/* We're airborne Set socket buffersize */
rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
return 0;
/* Yargs. It didn't work out. */
out_no_root:
dprintk("nfs_sb_init: get root inode failed: errno %d\n", -no_root_error);
if (!IS_ERR(root_inode))
iput(root_inode);
return no_root_error;
}
/*
* Initialise the timeout values for a connection
*/
static void nfs_init_timeout_values(struct rpc_timeout *to, int proto, unsigned int timeo, unsigned int retrans)
{
to->to_initval = timeo * HZ / 10;
to->to_retries = retrans;
if (!to->to_retries)
to->to_retries = 2;
switch (proto) {
case IPPROTO_TCP:
if (!to->to_initval)
to->to_initval = 60 * HZ;
if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
to->to_initval = NFS_MAX_TCP_TIMEOUT;
to->to_increment = to->to_initval;
to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
to->to_exponential = 0;
break;
case IPPROTO_UDP:
default:
if (!to->to_initval)
to->to_initval = 11 * HZ / 10;
if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
to->to_initval = NFS_MAX_UDP_TIMEOUT;
to->to_maxval = NFS_MAX_UDP_TIMEOUT;
to->to_exponential = 1;
break;
}
}
/*
* Create an RPC client handle.
*/
static struct rpc_clnt *
nfs_create_client(struct nfs_server *server, const struct nfs_mount_data *data)
{
struct rpc_timeout timeparms;
struct rpc_xprt *xprt = NULL;
struct rpc_clnt *clnt = NULL;
int proto = (data->flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP;
nfs_init_timeout_values(&timeparms, proto, data->timeo, data->retrans);
server->retrans_timeo = timeparms.to_initval;
server->retrans_count = timeparms.to_retries;
/* create transport and client */
xprt = xprt_create_proto(proto, &server->addr, &timeparms);
if (IS_ERR(xprt)) {
dprintk("%s: cannot create RPC transport. Error = %ld\n",
__FUNCTION__, PTR_ERR(xprt));
return (struct rpc_clnt *)xprt;
}
clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
server->rpc_ops->version, data->pseudoflavor);
if (IS_ERR(clnt)) {
dprintk("%s: cannot create RPC client. Error = %ld\n",
__FUNCTION__, PTR_ERR(xprt));
goto out_fail;
}
clnt->cl_intr = 1;
clnt->cl_softrtry = 1;
return clnt;
out_fail:
return clnt;
}
/*
* Clone a server record
*/
static struct nfs_server *nfs_clone_server(struct super_block *sb, struct nfs_clone_mount *data)
{
struct nfs_server *server = NFS_SB(sb);
struct nfs_server *parent = NFS_SB(data->sb);
struct inode *root_inode;
struct nfs_fsinfo fsinfo;
void *err = ERR_PTR(-ENOMEM);
sb->s_op = data->sb->s_op;
sb->s_blocksize = data->sb->s_blocksize;
sb->s_blocksize_bits = data->sb->s_blocksize_bits;
sb->s_maxbytes = data->sb->s_maxbytes;
server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
server->io_stats = nfs_alloc_iostats();
if (server->io_stats == NULL)
goto out;
server->client = rpc_clone_client(parent->client);
if (IS_ERR((err = server->client)))
goto out;
if (!IS_ERR(parent->client_sys)) {
server->client_sys = rpc_clone_client(parent->client_sys);
if (IS_ERR((err = server->client_sys)))
goto out;
}
if (!IS_ERR(parent->client_acl)) {
server->client_acl = rpc_clone_client(parent->client_acl);
if (IS_ERR((err = server->client_acl)))
goto out;
}
root_inode = nfs_fhget(sb, data->fh, data->fattr);
if (!root_inode)
goto out;
sb->s_root = d_alloc_root(root_inode);
if (!sb->s_root)
goto out_put_root;
fsinfo.fattr = data->fattr;
if (NFS_PROTO(root_inode)->fsinfo(server, data->fh, &fsinfo) == 0)
nfs_super_set_maxbytes(sb, fsinfo.maxfilesize);
sb->s_root->d_op = server->rpc_ops->dentry_ops;
sb->s_flags |= MS_ACTIVE;
return server;
out_put_root:
iput(root_inode);
out:
return err;
}
/*
* Copy an existing superblock and attach revised data
*/
static int nfs_clone_generic_sb(struct nfs_clone_mount *data,
struct super_block *(*fill_sb)(struct nfs_server *, struct nfs_clone_mount *),
struct nfs_server *(*fill_server)(struct super_block *, struct nfs_clone_mount *),
struct vfsmount *mnt)
{
struct nfs_server *server;
struct nfs_server *parent = NFS_SB(data->sb);
struct super_block *sb = ERR_PTR(-EINVAL);
char *hostname;
int error = -ENOMEM;
int len;
server = kmalloc(sizeof(struct nfs_server), GFP_KERNEL);
if (server == NULL)
goto out_err;
memcpy(server, parent, sizeof(*server));
hostname = (data->hostname != NULL) ? data->hostname : parent->hostname;
len = strlen(hostname) + 1;
server->hostname = kmalloc(len, GFP_KERNEL);
if (server->hostname == NULL)
goto free_server;
memcpy(server->hostname, hostname, len);
error = rpciod_up();
if (error != 0)
goto free_hostname;
sb = fill_sb(server, data);
if (IS_ERR(sb)) {
error = PTR_ERR(sb);
goto kill_rpciod;
}
if (sb->s_root)
goto out_rpciod_down;
server = fill_server(sb, data);
if (IS_ERR(server)) {
error = PTR_ERR(server);
goto out_deactivate;
}
return simple_set_mnt(mnt, sb);
out_deactivate:
up_write(&sb->s_umount);
deactivate_super(sb);
return error;
out_rpciod_down:
rpciod_down();
kfree(server->hostname);
kfree(server);
return simple_set_mnt(mnt, sb);
kill_rpciod:
rpciod_down();
free_hostname:
kfree(server->hostname);
free_server:
kfree(server);
out_err:
return error;
}
/*
* Set up an NFS2/3 superblock
*
* The way this works is that the mount process passes a structure
* in the data argument which contains the server's IP address
* and the root file handle obtained from the server's mount
* daemon. We stash these away in the private superblock fields.
*/
static int
nfs_fill_super(struct super_block *sb, struct nfs_mount_data *data, int silent)
{
struct nfs_server *server;
rpc_authflavor_t authflavor;
server = NFS_SB(sb);
sb->s_blocksize_bits = 0;
sb->s_blocksize = 0;
if (data->bsize)
sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
if (data->rsize)
server->rsize = nfs_block_size(data->rsize, NULL);
if (data->wsize)
server->wsize = nfs_block_size(data->wsize, NULL);
server->flags = data->flags & NFS_MOUNT_FLAGMASK;
server->acregmin = data->acregmin*HZ;
server->acregmax = data->acregmax*HZ;
server->acdirmin = data->acdirmin*HZ;
server->acdirmax = data->acdirmax*HZ;
/* Start lockd here, before we might error out */
if (!(server->flags & NFS_MOUNT_NONLM))
lockd_up();
server->namelen = data->namlen;
server->hostname = kmalloc(strlen(data->hostname) + 1, GFP_KERNEL);
if (!server->hostname)
return -ENOMEM;
strcpy(server->hostname, data->hostname);
/* Check NFS protocol revision and initialize RPC op vector
* and file handle pool. */
#ifdef CONFIG_NFS_V3
if (server->flags & NFS_MOUNT_VER3) {
server->rpc_ops = &nfs_v3_clientops;
server->caps |= NFS_CAP_READDIRPLUS;
} else {
server->rpc_ops = &nfs_v2_clientops;
}
#else
server->rpc_ops = &nfs_v2_clientops;
#endif
/* Fill in pseudoflavor for mount version < 5 */
if (!(data->flags & NFS_MOUNT_SECFLAVOUR))
data->pseudoflavor = RPC_AUTH_UNIX;
authflavor = data->pseudoflavor; /* save for sb_init() */
/* XXX maybe we want to add a server->pseudoflavor field */
/* Create RPC client handles */
server->client = nfs_create_client(server, data);
if (IS_ERR(server->client))
return PTR_ERR(server->client);
/* RFC 2623, sec 2.3.2 */
if (authflavor != RPC_AUTH_UNIX) {
struct rpc_auth *auth;
server->client_sys = rpc_clone_client(server->client);
if (IS_ERR(server->client_sys))
return PTR_ERR(server->client_sys);
auth = rpcauth_create(RPC_AUTH_UNIX, server->client_sys);
if (IS_ERR(auth))
return PTR_ERR(auth);
} else {
atomic_inc(&server->client->cl_count);
server->client_sys = server->client;
}
if (server->flags & NFS_MOUNT_VER3) {
#ifdef CONFIG_NFS_V3_ACL
if (!(server->flags & NFS_MOUNT_NOACL)) {
server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
/* No errors! Assume that Sun nfsacls are supported */
if (!IS_ERR(server->client_acl))
server->caps |= NFS_CAP_ACLS;
}
#else
server->flags &= ~NFS_MOUNT_NOACL;
#endif /* CONFIG_NFS_V3_ACL */
/*
* The VFS shouldn't apply the umask to mode bits. We will
* do so ourselves when necessary.
*/
sb->s_flags |= MS_POSIXACL;
if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
server->namelen = NFS3_MAXNAMLEN;
sb->s_time_gran = 1;
} else {
if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
server->namelen = NFS2_MAXNAMLEN;
}
sb->s_op = &nfs_sops;
return nfs_sb_init(sb, authflavor);
}
static int nfs_set_super(struct super_block *s, void *data)
{
s->s_fs_info = data;
return set_anon_super(s, data);
}
static int nfs_compare_super(struct super_block *sb, void *data)
{
struct nfs_server *server = data;
struct nfs_server *old = NFS_SB(sb);
if (old->addr.sin_addr.s_addr != server->addr.sin_addr.s_addr)
return 0;
if (old->addr.sin_port != server->addr.sin_port)
return 0;
return !nfs_compare_fh(&old->fh, &server->fh);
}
static int nfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
{
int error;
struct nfs_server *server = NULL;
struct super_block *s;
struct nfs_fh *root;
struct nfs_mount_data *data = raw_data;
error = -EINVAL;
if (data == NULL) {
dprintk("%s: missing data argument\n", __FUNCTION__);
goto out_err_noserver;
}
if (data->version <= 0 || data->version > NFS_MOUNT_VERSION) {
dprintk("%s: bad mount version\n", __FUNCTION__);
goto out_err_noserver;
}
switch (data->version) {
case 1:
data->namlen = 0;
case 2:
data->bsize = 0;
case 3:
if (data->flags & NFS_MOUNT_VER3) {
dprintk("%s: mount structure version %d does not support NFSv3\n",
__FUNCTION__,
data->version);
goto out_err_noserver;
}
data->root.size = NFS2_FHSIZE;
memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
case 4:
if (data->flags & NFS_MOUNT_SECFLAVOUR) {
dprintk("%s: mount structure version %d does not support strong security\n",
__FUNCTION__,
data->version);
goto out_err_noserver;
}
case 5:
memset(data->context, 0, sizeof(data->context));
}
#ifndef CONFIG_NFS_V3
/* If NFSv3 is not compiled in, return -EPROTONOSUPPORT */
error = -EPROTONOSUPPORT;
if (data->flags & NFS_MOUNT_VER3) {
dprintk("%s: NFSv3 not compiled into kernel\n", __FUNCTION__);
goto out_err_noserver;
}
#endif /* CONFIG_NFS_V3 */
error = -ENOMEM;
server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
if (!server)
goto out_err_noserver;
/* Zero out the NFS state stuff */
init_nfsv4_state(server);
server->client = server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
root = &server->fh;
if (data->flags & NFS_MOUNT_VER3)
root->size = data->root.size;
else
root->size = NFS2_FHSIZE;
error = -EINVAL;
if (root->size > sizeof(root->data)) {
dprintk("%s: invalid root filehandle\n", __FUNCTION__);
goto out_err;
}
memcpy(root->data, data->root.data, root->size);
/* We now require that the mount process passes the remote address */
memcpy(&server->addr, &data->addr, sizeof(server->addr));
if (server->addr.sin_addr.s_addr == INADDR_ANY) {
dprintk("%s: mount program didn't pass remote address!\n",
__FUNCTION__);
goto out_err;
}
/* Fire up rpciod if not yet running */
error = rpciod_up();
if (error < 0) {
dprintk("%s: couldn't start rpciod! Error = %d\n",
__FUNCTION__, error);
goto out_err;
}
s = sget(fs_type, nfs_compare_super, nfs_set_super, server);
if (IS_ERR(s)) {
error = PTR_ERR(s);
goto out_err_rpciod;
}
if (s->s_root)
goto out_rpciod_down;
s->s_flags = flags;
error = nfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
up_write(&s->s_umount);
deactivate_super(s);
return error;
}
s->s_flags |= MS_ACTIVE;
return simple_set_mnt(mnt, s);
out_rpciod_down:
rpciod_down();
kfree(server);
return simple_set_mnt(mnt, s);
out_err_rpciod:
rpciod_down();
out_err:
kfree(server);
out_err_noserver:
return error;
}
static void nfs_kill_super(struct super_block *s)
{
struct nfs_server *server = NFS_SB(s);
kill_anon_super(s);
if (!IS_ERR(server->client))
rpc_shutdown_client(server->client);
if (!IS_ERR(server->client_sys))
rpc_shutdown_client(server->client_sys);
if (!IS_ERR(server->client_acl))
rpc_shutdown_client(server->client_acl);
if (!(server->flags & NFS_MOUNT_NONLM))
lockd_down(); /* release rpc.lockd */
rpciod_down(); /* release rpciod */
nfs_free_iostats(server->io_stats);
kfree(server->hostname);
kfree(server);
nfs_release_automount_timer();
}
static struct super_block *nfs_clone_sb(struct nfs_server *server, struct nfs_clone_mount *data)
{
struct super_block *sb;
server->fsid = data->fattr->fsid;
nfs_copy_fh(&server->fh, data->fh);
sb = sget(&nfs_fs_type, nfs_compare_super, nfs_set_super, server);
if (!IS_ERR(sb) && sb->s_root == NULL && !(server->flags & NFS_MOUNT_NONLM))
lockd_up();
return sb;
}
static int nfs_clone_nfs_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
{
struct nfs_clone_mount *data = raw_data;
return nfs_clone_generic_sb(data, nfs_clone_sb, nfs_clone_server, mnt);
}
#ifdef CONFIG_NFS_V4
static struct rpc_clnt *nfs4_create_client(struct nfs_server *server,
struct rpc_timeout *timeparms, int proto, rpc_authflavor_t flavor)
{
struct nfs_client *clp;
struct rpc_xprt *xprt = NULL;
struct rpc_clnt *clnt = NULL;
int err = -EIO;
clp = nfs4_get_client(&server->addr.sin_addr);
if (!clp) {
dprintk("%s: failed to create NFS4 client.\n", __FUNCTION__);
return ERR_PTR(err);
}
/* Now create transport and client */
down_write(&clp->cl_sem);
if (IS_ERR(clp->cl_rpcclient)) {
xprt = xprt_create_proto(proto, &server->addr, timeparms);
if (IS_ERR(xprt)) {
up_write(&clp->cl_sem);
err = PTR_ERR(xprt);
dprintk("%s: cannot create RPC transport. Error = %d\n",
__FUNCTION__, err);
goto out_fail;
}
/* Bind to a reserved port! */
xprt->resvport = 1;
clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
server->rpc_ops->version, flavor);
if (IS_ERR(clnt)) {
up_write(&clp->cl_sem);
err = PTR_ERR(clnt);
dprintk("%s: cannot create RPC client. Error = %d\n",
__FUNCTION__, err);
goto out_fail;
}
clnt->cl_intr = 1;
clnt->cl_softrtry = 1;
clp->cl_rpcclient = clnt;
memcpy(clp->cl_ipaddr, server->ip_addr, sizeof(clp->cl_ipaddr));
if (nfs_idmap_new(clp) < 0)
goto out_fail;
}
list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
clnt = rpc_clone_client(clp->cl_rpcclient);
if (!IS_ERR(clnt))
server->nfs_client = clp;
up_write(&clp->cl_sem);
clp = NULL;
if (IS_ERR(clnt)) {
dprintk("%s: cannot create RPC client. Error = %d\n",
__FUNCTION__, err);
return clnt;
}
if (server->nfs_client->cl_idmap == NULL) {
dprintk("%s: failed to create idmapper.\n", __FUNCTION__);
return ERR_PTR(-ENOMEM);
}
if (clnt->cl_auth->au_flavor != flavor) {
struct rpc_auth *auth;
auth = rpcauth_create(flavor, clnt);
if (IS_ERR(auth)) {
dprintk("%s: couldn't create credcache!\n", __FUNCTION__);
return (struct rpc_clnt *)auth;
}
}
return clnt;
out_fail:
if (clp)
nfs4_put_client(clp);
return ERR_PTR(err);
}
/*
* Set up an NFS4 superblock
*/
static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data, int silent)
{
struct nfs_server *server;
struct rpc_timeout timeparms;
rpc_authflavor_t authflavour;
int err = -EIO;
sb->s_blocksize_bits = 0;
sb->s_blocksize = 0;
server = NFS_SB(sb);
if (data->rsize != 0)
server->rsize = nfs_block_size(data->rsize, NULL);
if (data->wsize != 0)
server->wsize = nfs_block_size(data->wsize, NULL);
server->flags = data->flags & NFS_MOUNT_FLAGMASK;
server->caps = NFS_CAP_ATOMIC_OPEN;
server->acregmin = data->acregmin*HZ;
server->acregmax = data->acregmax*HZ;
server->acdirmin = data->acdirmin*HZ;
server->acdirmax = data->acdirmax*HZ;
server->rpc_ops = &nfs_v4_clientops;
nfs_init_timeout_values(&timeparms, data->proto, data->timeo, data->retrans);
server->retrans_timeo = timeparms.to_initval;
server->retrans_count = timeparms.to_retries;
/* Now create transport and client */
authflavour = RPC_AUTH_UNIX;
if (data->auth_flavourlen != 0) {
if (data->auth_flavourlen != 1) {
dprintk("%s: Invalid number of RPC auth flavours %d.\n",
__FUNCTION__, data->auth_flavourlen);
err = -EINVAL;
goto out_fail;
}
if (copy_from_user(&authflavour, data->auth_flavours, sizeof(authflavour))) {
err = -EFAULT;
goto out_fail;
}
}
server->client = nfs4_create_client(server, &timeparms, data->proto, authflavour);
if (IS_ERR(server->client)) {
err = PTR_ERR(server->client);
dprintk("%s: cannot create RPC client. Error = %d\n",
__FUNCTION__, err);
goto out_fail;
}
sb->s_time_gran = 1;
sb->s_op = &nfs4_sops;
err = nfs_sb_init(sb, authflavour);
out_fail:
return err;
}
static int nfs4_compare_super(struct super_block *sb, void *data)
{
struct nfs_server *server = data;
struct nfs_server *old = NFS_SB(sb);
if (strcmp(server->hostname, old->hostname) != 0)
return 0;
if (strcmp(server->mnt_path, old->mnt_path) != 0)
return 0;
return 1;
}
static void *
nfs_copy_user_string(char *dst, struct nfs_string *src, int maxlen)
{
void *p = NULL;
if (!src->len)
return ERR_PTR(-EINVAL);
if (src->len < maxlen)
maxlen = src->len;
if (dst == NULL) {
p = dst = kmalloc(maxlen + 1, GFP_KERNEL);
if (p == NULL)
return ERR_PTR(-ENOMEM);
}
if (copy_from_user(dst, src->data, maxlen)) {
kfree(p);
return ERR_PTR(-EFAULT);
}
dst[maxlen] = '\0';
return dst;
}
static int nfs4_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
{
int error;
struct nfs_server *server;
struct super_block *s;
struct nfs4_mount_data *data = raw_data;
void *p;
if (data == NULL) {
dprintk("%s: missing data argument\n", __FUNCTION__);
return -EINVAL;
}
if (data->version <= 0 || data->version > NFS4_MOUNT_VERSION) {
dprintk("%s: bad mount version\n", __FUNCTION__);
return -EINVAL;
}
server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
if (!server)
return -ENOMEM;
/* Zero out the NFS state stuff */
init_nfsv4_state(server);
server->client = server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
p = nfs_copy_user_string(NULL, &data->hostname, 256);
if (IS_ERR(p))
goto out_err;
server->hostname = p;
p = nfs_copy_user_string(NULL, &data->mnt_path, 1024);
if (IS_ERR(p))
goto out_err;
server->mnt_path = p;
p = nfs_copy_user_string(server->ip_addr, &data->client_addr,
sizeof(server->ip_addr) - 1);
if (IS_ERR(p))
goto out_err;
/* We now require that the mount process passes the remote address */
if (data->host_addrlen != sizeof(server->addr)) {
error = -EINVAL;
goto out_free;
}
if (copy_from_user(&server->addr, data->host_addr, sizeof(server->addr))) {
error = -EFAULT;
goto out_free;
}
if (server->addr.sin_family != AF_INET ||
server->addr.sin_addr.s_addr == INADDR_ANY) {
dprintk("%s: mount program didn't pass remote IP address!\n",
__FUNCTION__);
error = -EINVAL;
goto out_free;
}
/* Fire up rpciod if not yet running */
error = rpciod_up();
if (error < 0) {
dprintk("%s: couldn't start rpciod! Error = %d\n",
__FUNCTION__, error);
goto out_free;
}
s = sget(fs_type, nfs4_compare_super, nfs_set_super, server);
if (IS_ERR(s)) {
error = PTR_ERR(s);
goto out_free;
}
if (s->s_root) {
kfree(server->mnt_path);
kfree(server->hostname);
kfree(server);
return simple_set_mnt(mnt, s);
}
s->s_flags = flags;
error = nfs4_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
up_write(&s->s_umount);
deactivate_super(s);
return error;
}
s->s_flags |= MS_ACTIVE;
return simple_set_mnt(mnt, s);
out_err:
error = PTR_ERR(p);
out_free:
kfree(server->mnt_path);
kfree(server->hostname);
kfree(server);
return error;
}
static void nfs4_kill_super(struct super_block *sb)
{
struct nfs_server *server = NFS_SB(sb);
nfs_return_all_delegations(sb);
kill_anon_super(sb);
nfs4_renewd_prepare_shutdown(server);
if (server->client != NULL && !IS_ERR(server->client))
rpc_shutdown_client(server->client);
destroy_nfsv4_state(server);
rpciod_down();
nfs_free_iostats(server->io_stats);
kfree(server->hostname);
kfree(server);
nfs_release_automount_timer();
}
/*
* Constructs the SERVER-side path
*/
static inline char *nfs4_dup_path(const struct dentry *dentry)
{
char *page = (char *) __get_free_page(GFP_USER);
char *path;
path = nfs4_path(dentry, page, PAGE_SIZE);
if (!IS_ERR(path)) {
int len = PAGE_SIZE + page - path;
char *tmp = path;
path = kmalloc(len, GFP_KERNEL);
if (path)
memcpy(path, tmp, len);
else
path = ERR_PTR(-ENOMEM);
}
free_page((unsigned long)page);
return path;
}
static struct super_block *nfs4_clone_sb(struct nfs_server *server, struct nfs_clone_mount *data)
{
const struct dentry *dentry = data->dentry;
struct nfs_client *clp = server->nfs_client;
struct super_block *sb;
server->fsid = data->fattr->fsid;
nfs_copy_fh(&server->fh, data->fh);
server->mnt_path = nfs4_dup_path(dentry);
if (IS_ERR(server->mnt_path)) {
sb = (struct super_block *)server->mnt_path;
goto err;
}
sb = sget(&nfs4_fs_type, nfs4_compare_super, nfs_set_super, server);
if (IS_ERR(sb) || sb->s_root)
goto free_path;
nfs4_server_capabilities(server, &server->fh);
down_write(&clp->cl_sem);
atomic_inc(&clp->cl_count);
list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
up_write(&clp->cl_sem);
return sb;
free_path:
kfree(server->mnt_path);
err:
server->mnt_path = NULL;
return sb;
}
static int nfs_clone_nfs4_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
{
struct nfs_clone_mount *data = raw_data;
return nfs_clone_generic_sb(data, nfs4_clone_sb, nfs_clone_server, mnt);
}
static struct super_block *nfs4_referral_sb(struct nfs_server *server, struct nfs_clone_mount *data)
{
struct super_block *sb = ERR_PTR(-ENOMEM);
int len;
len = strlen(data->mnt_path) + 1;
server->mnt_path = kmalloc(len, GFP_KERNEL);
if (server->mnt_path == NULL)
goto err;
memcpy(server->mnt_path, data->mnt_path, len);
memcpy(&server->addr, data->addr, sizeof(struct sockaddr_in));
sb = sget(&nfs4_fs_type, nfs4_compare_super, nfs_set_super, server);
if (IS_ERR(sb) || sb->s_root)
goto free_path;
return sb;
free_path:
kfree(server->mnt_path);
err:
server->mnt_path = NULL;
return sb;
}
static struct nfs_server *nfs4_referral_server(struct super_block *sb, struct nfs_clone_mount *data)
{
struct nfs_server *server = NFS_SB(sb);
struct rpc_timeout timeparms;
int proto, timeo, retrans;
void *err;
proto = IPPROTO_TCP;
/* Since we are following a referral and there may be alternatives,
set the timeouts and retries to low values */
timeo = 2;
retrans = 1;
nfs_init_timeout_values(&timeparms, proto, timeo, retrans);
server->client = nfs4_create_client(server, &timeparms, proto, data->authflavor);
if (IS_ERR((err = server->client)))
goto out_err;
sb->s_time_gran = 1;
sb->s_op = &nfs4_sops;
err = ERR_PTR(nfs_sb_init(sb, data->authflavor));
if (!IS_ERR(err))
return server;
out_err:
return (struct nfs_server *)err;
}
static int nfs_referral_nfs4_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
{
struct nfs_clone_mount *data = raw_data;
return nfs_clone_generic_sb(data, nfs4_referral_sb, nfs4_referral_server, mnt);
}
#endif