super.c 26.0 KB
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/*
 *  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>
 *
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 * - 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())
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 */

#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>
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#include <linux/magic.h>
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#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

static void nfs_umount_begin(struct vfsmount *, int);
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static int  nfs_statfs(struct dentry *, struct kstatfs *);
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static int  nfs_show_options(struct seq_file *, struct vfsmount *);
static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
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static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
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static int nfs_xdev_get_sb(struct file_system_type *fs_type,
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		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
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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,
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	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
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};

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

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static const struct super_operations nfs_sops = {
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	.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
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static int nfs4_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
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static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
static int nfs4_referral_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
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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,
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	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
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};

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struct file_system_type nfs4_xdev_fs_type = {
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	.owner		= THIS_MODULE,
	.name		= "nfs4",
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	.get_sb		= nfs4_xdev_get_sb,
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	.kill_sb	= nfs4_kill_super,
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	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
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};

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struct file_system_type nfs4_referral_fs_type = {
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	.owner		= THIS_MODULE,
	.name		= "nfs4",
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	.get_sb		= nfs4_referral_get_sb,
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	.kill_sb	= nfs4_kill_super,
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	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
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};

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static const struct super_operations nfs4_sops = {
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	.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

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static struct shrinker *acl_shrinker;

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/*
 * 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 = nfs_register_sysctl();
	if (ret < 0)
		goto error_1;
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#ifdef CONFIG_NFS_V4
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	ret = register_filesystem(&nfs4_fs_type);
	if (ret < 0)
		goto error_2;
#endif
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	acl_shrinker = set_shrinker(DEFAULT_SEEKS, nfs_access_cache_shrinker);
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	return 0;

#ifdef CONFIG_NFS_V4
error_2:
	nfs_unregister_sysctl();
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#endif
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error_1:
	unregister_filesystem(&nfs_fs_type);
error_0:
	return ret;
}

/*
 * Unregister the NFS filesystems
 */
void __exit unregister_nfs_fs(void)
{
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	if (acl_shrinker != NULL)
		remove_shrinker(acl_shrinker);
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#ifdef CONFIG_NFS_V4
	unregister_filesystem(&nfs4_fs_type);
	nfs_unregister_sysctl();
#endif
	unregister_filesystem(&nfs_fs_type);
}

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

	lock_kernel();

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	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
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	if (error < 0)
		goto out_err;
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	buf->f_type = NFS_SUPER_MAGIC;
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	/*
	 * 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.
	 */
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	buf->f_frsize = dentry->d_sb->s_blocksize;
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	/*
	 * 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.
	 */
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	buf->f_bsize = dentry->d_sb->s_blocksize;
	blockbits = dentry->d_sb->s_blocksize_bits;
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	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;
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	unlock_kernel();
	return 0;

 out_err:
	dprintk("%s: statfs error = %d\n", __FUNCTION__, -error);
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	unlock_kernel();
	return error;
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}

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/*
 * Map the security flavour number to a name
 */
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static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
{
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	static const struct {
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		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;
}

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/*
 * 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)
{
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	static const struct proc_nfs_info {
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		int flag;
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		const char *str;
		const char *nostr;
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	} 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 }
	};
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	const struct proc_nfs_info *nfs_infop;
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	struct nfs_client *clp = nfss->nfs_client;
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	char buf[12];
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	const char *proto;
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	seq_printf(m, ",vers=%d", clp->rpc_ops->version);
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	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);
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	seq_printf(m, ",timeo=%lu", 10U * clp->retrans_timeo / HZ);
	seq_printf(m, ",retrans=%u", clp->retrans_count);
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	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
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}

/*
 * 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=");
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	seq_escape(m, nfss->nfs_client->cl_hostname, " \t\n\\");
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	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
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	if (nfss->nfs_client->cl_nfsversion == 4) {
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		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
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 * in response to xdev traversals and referrals
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 */
static void nfs_umount_begin(struct vfsmount *vfsmnt, int flags)
{
	shrink_submounts(vfsmnt, &nfs_automount_list);
}

/*
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 * Validate the NFS2/NFS3 mount data
 * - fills in the mount root filehandle
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 */
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static int nfs_validate_mount_data(struct nfs_mount_data *data,
				   struct nfs_fh *mntfh)
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{
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	if (data == NULL) {
		dprintk("%s: missing data argument\n", __FUNCTION__);
		return -EINVAL;
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	}

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	if (data->version <= 0 || data->version > NFS_MOUNT_VERSION) {
		dprintk("%s: bad mount version\n", __FUNCTION__);
		return -EINVAL;
	}
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	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);
				return -EINVAL;
			}
			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);
				return -EINVAL;
			}
		case 5:
			memset(data->context, 0, sizeof(data->context));
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	}
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	/* Set the pseudoflavor */
	if (!(data->flags & NFS_MOUNT_SECFLAVOUR))
		data->pseudoflavor = RPC_AUTH_UNIX;

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#ifndef CONFIG_NFS_V3
	/* If NFSv3 is not compiled in, return -EPROTONOSUPPORT */
	if (data->flags & NFS_MOUNT_VER3) {
		dprintk("%s: NFSv3 not compiled into kernel\n", __FUNCTION__);
		return -EPROTONOSUPPORT;
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	}
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#endif /* CONFIG_NFS_V3 */
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	/* We now require that the mount process passes the remote address */
	if (data->addr.sin_addr.s_addr == INADDR_ANY) {
		dprintk("%s: mount program didn't pass remote address!\n",
			__FUNCTION__);
		return -EINVAL;
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	}

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	/* Prepare the root filehandle */
	if (data->flags & NFS_MOUNT_VER3)
		mntfh->size = data->root.size;
	else
		mntfh->size = NFS2_FHSIZE;
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	if (mntfh->size > sizeof(mntfh->data)) {
		dprintk("%s: invalid root filehandle\n", __FUNCTION__);
		return -EINVAL;
	}

	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);
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	return 0;
}

/*
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 * Initialise the common bits of the superblock
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 */
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static inline void nfs_initialise_sb(struct super_block *sb)
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{
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	struct nfs_server *server = NFS_SB(sb);
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	sb->s_magic = NFS_SUPER_MAGIC;
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	/* 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));
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	if (sb->s_blocksize == 0)
		sb->s_blocksize = nfs_block_bits(server->wsize,
						 &sb->s_blocksize_bits);
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David Howells 已提交
531

532 533
	if (server->flags & NFS_MOUNT_NOAC)
		sb->s_flags |= MS_SYNCHRONOUS;
D
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534

535
	nfs_super_set_maxbytes(sb, server->maxfilesize);
D
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536 537 538
}

/*
539
 * Finish setting up an NFS2/3 superblock
D
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540
 */
541
static void nfs_fill_super(struct super_block *sb, struct nfs_mount_data *data)
D
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542 543
{
	struct nfs_server *server = NFS_SB(sb);
544

545 546 547 548
	sb->s_blocksize_bits = 0;
	sb->s_blocksize = 0;
	if (data->bsize)
		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
D
David Howells 已提交
549

550 551 552 553 554 555
	if (server->flags & NFS_MOUNT_VER3) {
		/* The VFS shouldn't apply the umask to mode bits. We will do
		 * so ourselves when necessary.
		 */
		sb->s_flags |= MS_POSIXACL;
		sb->s_time_gran = 1;
556
	}
557 558 559

	sb->s_op = &nfs_sops;
 	nfs_initialise_sb(sb);
D
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560 561 562
}

/*
563
 * Finish setting up a cloned NFS2/3 superblock
D
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564
 */
565 566
static void nfs_clone_super(struct super_block *sb,
			    const struct super_block *old_sb)
D
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567
{
568 569 570 571 572
	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;
D
David Howells 已提交
573 574

	if (server->flags & NFS_MOUNT_VER3) {
575 576
		/* The VFS shouldn't apply the umask to mode bits. We will do
		 * so ourselves when necessary.
D
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577 578 579 580 581
		 */
		sb->s_flags |= MS_POSIXACL;
		sb->s_time_gran = 1;
	}

582 583
	sb->s_op = old_sb->s_op;
 	nfs_initialise_sb(sb);
D
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584 585
}

586
static int nfs_set_super(struct super_block *s, void *_server)
D
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587
{
588 589 590 591 592 593 594 595
	struct nfs_server *server = _server;
	int ret;

	s->s_fs_info = server;
	ret = set_anon_super(s, server);
	if (ret == 0)
		server->s_dev = s->s_dev;
	return ret;
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596 597 598 599
}

static int nfs_compare_super(struct super_block *sb, void *data)
{
600
	struct nfs_server *server = data, *old = NFS_SB(sb);
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601

602
	if (old->nfs_client != server->nfs_client)
D
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603
		return 0;
604
	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
D
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605
		return 0;
606
	return 1;
D
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607 608
}

609 610
static int nfs_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
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611 612 613
{
	struct nfs_server *server = NULL;
	struct super_block *s;
614
	struct nfs_fh mntfh;
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615
	struct nfs_mount_data *data = raw_data;
616 617
	struct dentry *mntroot;
	int error;
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618

619 620 621 622
	/* Validate the mount data */
	error = nfs_validate_mount_data(data, &mntfh);
	if (error < 0)
		return error;
D
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623

624 625 626 627
	/* Get a volume representation */
	server = nfs_create_server(data, &mntfh);
	if (IS_ERR(server)) {
		error = PTR_ERR(server);
628
		goto out_err_noserver;
D
David Howells 已提交
629 630
	}

631
	/* Get a superblock - note that we may end up sharing one that already exists */
D
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632
	s = sget(fs_type, nfs_compare_super, nfs_set_super, server);
633 634
	if (IS_ERR(s)) {
		error = PTR_ERR(s);
635
		goto out_err_nosb;
636 637
	}

638 639 640 641
	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
	}
D
David Howells 已提交
642

643 644 645 646 647
	if (!s->s_root) {
		/* initial superblock/root creation */
		s->s_flags = flags;
		nfs_fill_super(s, data);
	}
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648

649 650 651 652
	mntroot = nfs_get_root(s, &mntfh);
	if (IS_ERR(mntroot)) {
		error = PTR_ERR(mntroot);
		goto error_splat_super;
D
David Howells 已提交
653
	}
654

655 656 657 658
	s->s_flags |= MS_ACTIVE;
	mnt->mnt_sb = s;
	mnt->mnt_root = mntroot;
	return 0;
659

660 661
out_err_nosb:
	nfs_free_server(server);
662 663
out_err_noserver:
	return error;
664 665 666 667 668

error_splat_super:
	up_write(&s->s_umount);
	deactivate_super(s);
	return error;
D
David Howells 已提交
669 670
}

671 672 673
/*
 * Destroy an NFS2/3 superblock
 */
D
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674 675 676 677 678
static void nfs_kill_super(struct super_block *s)
{
	struct nfs_server *server = NFS_SB(s);

	kill_anon_super(s);
679
	nfs_free_server(server);
D
David Howells 已提交
680 681
}

682 683 684 685 686 687
/*
 * Clone an NFS2/3 server record on xdev traversal (FSID-change)
 */
static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
			   const char *dev_name, void *raw_data,
			   struct vfsmount *mnt)
D
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688 689
{
	struct nfs_clone_mount *data = raw_data;
690 691 692 693
	struct super_block *s;
	struct nfs_server *server;
	struct dentry *mntroot;
	int error;
D
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694

695
	dprintk("--> nfs_xdev_get_sb()\n");
D
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696

697 698 699 700 701 702
	/* create a new volume representation */
	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
	if (IS_ERR(server)) {
		error = PTR_ERR(server);
		goto out_err_noserver;
	}
703

704 705 706 707 708 709
	/* Get a superblock - note that we may end up sharing one that already exists */
	s = sget(&nfs_fs_type, nfs_compare_super, nfs_set_super, server);
	if (IS_ERR(s)) {
		error = PTR_ERR(s);
		goto out_err_nosb;
	}
710

711 712 713
	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
D
David Howells 已提交
714
	}
715

716 717 718 719 720
	if (!s->s_root) {
		/* initial superblock/root creation */
		s->s_flags = flags;
		nfs_clone_super(s, data->sb);
	}
D
David Howells 已提交
721

722 723 724 725
	mntroot = nfs_get_root(s, data->fh);
	if (IS_ERR(mntroot)) {
		error = PTR_ERR(mntroot);
		goto error_splat_super;
D
David Howells 已提交
726 727
	}

728 729 730
	s->s_flags |= MS_ACTIVE;
	mnt->mnt_sb = s;
	mnt->mnt_root = mntroot;
D
David Howells 已提交
731

732 733
	dprintk("<-- nfs_xdev_get_sb() = 0\n");
	return 0;
734

735 736 737 738 739
out_err_nosb:
	nfs_free_server(server);
out_err_noserver:
	dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
	return error;
D
David Howells 已提交
740

741 742 743 744 745
error_splat_super:
	up_write(&s->s_umount);
	deactivate_super(s);
	dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
	return error;
D
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746 747
}

748 749
#ifdef CONFIG_NFS_V4

D
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750
/*
751
 * Finish setting up a cloned NFS4 superblock
D
David Howells 已提交
752
 */
753 754
static void nfs4_clone_super(struct super_block *sb,
			    const struct super_block *old_sb)
D
David Howells 已提交
755
{
756 757 758
	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
	sb->s_blocksize = old_sb->s_blocksize;
	sb->s_maxbytes = old_sb->s_maxbytes;
D
David Howells 已提交
759
	sb->s_time_gran = 1;
760 761
	sb->s_op = old_sb->s_op;
 	nfs_initialise_sb(sb);
D
David Howells 已提交
762 763
}

764 765 766 767
/*
 * Set up an NFS4 superblock
 */
static void nfs4_fill_super(struct super_block *sb)
D
David Howells 已提交
768
{
769 770 771
	sb->s_time_gran = 1;
	sb->s_op = &nfs4_sops;
	nfs_initialise_sb(sb);
D
David Howells 已提交
772 773
}

774
static void *nfs_copy_user_string(char *dst, struct nfs_string *src, int maxlen)
D
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775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794
{
	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;
}

795 796 797
/*
 * Get the superblock for an NFS4 mountpoint
 */
798 799
static int nfs4_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
D
David Howells 已提交
800 801
{
	struct nfs4_mount_data *data = raw_data;
802 803 804 805 806 807 808
	struct super_block *s;
	struct nfs_server *server;
	struct sockaddr_in addr;
	rpc_authflavor_t authflavour;
	struct nfs_fh mntfh;
	struct dentry *mntroot;
	char *mntpath = NULL, *hostname = NULL, ip_addr[16];
D
David Howells 已提交
809
	void *p;
810
	int error;
D
David Howells 已提交
811 812 813

	if (data == NULL) {
		dprintk("%s: missing data argument\n", __FUNCTION__);
814
		return -EINVAL;
D
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815 816 817
	}
	if (data->version <= 0 || data->version > NFS4_MOUNT_VERSION) {
		dprintk("%s: bad mount version\n", __FUNCTION__);
818
		return -EINVAL;
D
David Howells 已提交
819 820
	}

821 822 823 824 825 826 827 828 829 830 831 832 833 834
	/* We now require that the mount process passes the remote address */
	if (data->host_addrlen != sizeof(addr))
		return -EINVAL;

	if (copy_from_user(&addr, data->host_addr, sizeof(addr)))
		return -EFAULT;

	if (addr.sin_family != AF_INET ||
	    addr.sin_addr.s_addr == INADDR_ANY
	    ) {
		dprintk("%s: mount program didn't pass remote IP address!\n",
				__FUNCTION__);
		return -EINVAL;
	}
835 836
	/* RFC3530: The default port for NFS is 2049 */
	if (addr.sin_port == 0)
837
		addr.sin_port = htons(NFS_PORT);
838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854

	/* Grab the authentication type */
	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);
			error = -EINVAL;
			goto out_err_noserver;
		}

		if (copy_from_user(&authflavour, data->auth_flavours,
				   sizeof(authflavour))) {
			error = -EFAULT;
			goto out_err_noserver;
		}
	}
D
David Howells 已提交
855 856 857 858

	p = nfs_copy_user_string(NULL, &data->hostname, 256);
	if (IS_ERR(p))
		goto out_err;
859
	hostname = p;
D
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860 861 862 863

	p = nfs_copy_user_string(NULL, &data->mnt_path, 1024);
	if (IS_ERR(p))
		goto out_err;
864
	mntpath = p;
D
David Howells 已提交
865

866 867 868 869
	dprintk("MNTPATH: %s\n", mntpath);

	p = nfs_copy_user_string(ip_addr, &data->client_addr,
				 sizeof(ip_addr) - 1);
D
David Howells 已提交
870 871 872
	if (IS_ERR(p))
		goto out_err;

873 874 875 876 877 878
	/* Get a volume representation */
	server = nfs4_create_server(data, hostname, &addr, mntpath, ip_addr,
				    authflavour, &mntfh);
	if (IS_ERR(server)) {
		error = PTR_ERR(server);
		goto out_err_noserver;
D
David Howells 已提交
879 880
	}

881 882
	/* Get a superblock - note that we may end up sharing one that already exists */
	s = sget(fs_type, nfs_compare_super, nfs_set_super, server);
883 884
	if (IS_ERR(s)) {
		error = PTR_ERR(s);
D
David Howells 已提交
885
		goto out_free;
886 887
	}

888 889 890 891 892
	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
	}

893 894 895 896 897
	if (!s->s_root) {
		/* initial superblock/root creation */
		s->s_flags = flags;
		nfs4_fill_super(s);
	}
D
David Howells 已提交
898

899 900 901 902
	mntroot = nfs4_get_root(s, &mntfh);
	if (IS_ERR(mntroot)) {
		error = PTR_ERR(mntroot);
		goto error_splat_super;
D
David Howells 已提交
903
	}
904

D
David Howells 已提交
905
	s->s_flags |= MS_ACTIVE;
906 907 908 909 910 911
	mnt->mnt_sb = s;
	mnt->mnt_root = mntroot;
	kfree(mntpath);
	kfree(hostname);
	return 0;

D
David Howells 已提交
912
out_err:
913
	error = PTR_ERR(p);
914 915
	goto out_err_noserver;

D
David Howells 已提交
916
out_free:
917 918 919 920
	nfs_free_server(server);
out_err_noserver:
	kfree(mntpath);
	kfree(hostname);
921
	return error;
922 923 924 925 926

error_splat_super:
	up_write(&s->s_umount);
	deactivate_super(s);
	goto out_err_noserver;
D
David Howells 已提交
927 928 929 930 931 932 933 934 935 936
}

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);
937
	nfs_free_server(server);
D
David Howells 已提交
938 939 940
}

/*
941
 * Clone an NFS4 server record on xdev traversal (FSID-change)
D
David Howells 已提交
942
 */
943 944 945
static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
			    const char *dev_name, void *raw_data,
			    struct vfsmount *mnt)
D
David Howells 已提交
946
{
947 948 949 950 951
	struct nfs_clone_mount *data = raw_data;
	struct super_block *s;
	struct nfs_server *server;
	struct dentry *mntroot;
	int error;
D
David Howells 已提交
952

953
	dprintk("--> nfs4_xdev_get_sb()\n");
D
David Howells 已提交
954

955 956 957 958 959
	/* create a new volume representation */
	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
	if (IS_ERR(server)) {
		error = PTR_ERR(server);
		goto out_err_noserver;
D
David Howells 已提交
960 961
	}

962 963 964 965 966
	/* Get a superblock - note that we may end up sharing one that already exists */
	s = sget(&nfs_fs_type, nfs_compare_super, nfs_set_super, server);
	if (IS_ERR(s)) {
		error = PTR_ERR(s);
		goto out_err_nosb;
D
David Howells 已提交
967 968
	}

969 970 971 972
	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
	}
D
David Howells 已提交
973

974 975 976 977 978
	if (!s->s_root) {
		/* initial superblock/root creation */
		s->s_flags = flags;
		nfs4_clone_super(s, data->sb);
	}
D
David Howells 已提交
979

980 981 982 983 984
	mntroot = nfs4_get_root(s, data->fh);
	if (IS_ERR(mntroot)) {
		error = PTR_ERR(mntroot);
		goto error_splat_super;
	}
D
David Howells 已提交
985

986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003
	s->s_flags |= MS_ACTIVE;
	mnt->mnt_sb = s;
	mnt->mnt_root = mntroot;

	dprintk("<-- nfs4_xdev_get_sb() = 0\n");
	return 0;

out_err_nosb:
	nfs_free_server(server);
out_err_noserver:
	dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
	return error;

error_splat_super:
	up_write(&s->s_umount);
	deactivate_super(s);
	dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
	return error;
D
David Howells 已提交
1004 1005
}

1006 1007 1008 1009 1010 1011
/*
 * Create an NFS4 server record on referral traversal
 */
static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
				const char *dev_name, void *raw_data,
				struct vfsmount *mnt)
D
David Howells 已提交
1012 1013
{
	struct nfs_clone_mount *data = raw_data;
1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046
	struct super_block *s;
	struct nfs_server *server;
	struct dentry *mntroot;
	struct nfs_fh mntfh;
	int error;

	dprintk("--> nfs4_referral_get_sb()\n");

	/* create a new volume representation */
	server = nfs4_create_referral_server(data, &mntfh);
	if (IS_ERR(server)) {
		error = PTR_ERR(server);
		goto out_err_noserver;
	}

	/* Get a superblock - note that we may end up sharing one that already exists */
	s = sget(&nfs_fs_type, nfs_compare_super, nfs_set_super, server);
	if (IS_ERR(s)) {
		error = PTR_ERR(s);
		goto out_err_nosb;
	}

	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
	}

	if (!s->s_root) {
		/* initial superblock/root creation */
		s->s_flags = flags;
		nfs4_fill_super(s);
	}

1047
	mntroot = nfs4_get_root(s, &mntfh);
1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070
	if (IS_ERR(mntroot)) {
		error = PTR_ERR(mntroot);
		goto error_splat_super;
	}

	s->s_flags |= MS_ACTIVE;
	mnt->mnt_sb = s;
	mnt->mnt_root = mntroot;

	dprintk("<-- nfs4_referral_get_sb() = 0\n");
	return 0;

out_err_nosb:
	nfs_free_server(server);
out_err_noserver:
	dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
	return error;

error_splat_super:
	up_write(&s->s_umount);
	deactivate_super(s);
	dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
	return error;
D
David Howells 已提交
1071 1072
}

1073
#endif /* CONFIG_NFS_V4 */