Merge rsync://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

Conflicts:

	include/linux/kernel.h

1 files changed, 1537 insertions, 0 deletions

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
new file mode 100644
index 00000000000..e8a9bee74d9
--- /dev/null
+++ b/fs/nfs/super.c
@@ -0,0 +1,1537 @@
+/*
+ *  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
+
+#ifdef CONFIG_NFS_V4
+static const int nfs_set_port_min = 0;
+static const int nfs_set_port_max = 65535;
+
+static int param_set_port(const char *val, struct kernel_param *kp)
+{
+	char *endp;
+	int num = simple_strtol(val, &endp, 0);
+	if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)
+		return -EINVAL;
+	*((int *)kp->arg) = num;
+	return 0;
+}
+
+module_param_call(callback_tcpport, param_set_port, param_get_int,
+		 &nfs_callback_set_tcpport, 0644);
+#endif
+
+#ifdef CONFIG_NFS_V4
+static int param_set_idmap_timeout(const char *val, struct kernel_param *kp)
+{
+	char *endp;
+	int num = simple_strtol(val, &endp, 0);
+	int jif = num * HZ;
+	if (endp == val || *endp || num < 0 || jif < num)
+		return -EINVAL;
+	*((int *)kp->arg) = jif;
+	return 0;
+}
+
+module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int,
+		 &nfs_idmap_cache_timeout, 0644);
+#endif
+
+/*
+ * 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
+	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)
+{
+#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;
+
+}
+
+static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
+{
+	static 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 nfs4_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));
+		nfs_idmap_new(clp);
+	}
+	list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
+	clnt = rpc_clone_client(clp->cl_rpcclient);
+	if (!IS_ERR(clnt))
+		server->nfs4_state = 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->nfs4_state->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 nfs4_client *clp = server->nfs4_state;
+	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