super.c 26.1 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;

#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
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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();
error_1:
	unregister_filesystem(&nfs_fs_type);
#endif
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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	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.
	 */
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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;
 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;

}

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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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	if (server->flags & NFS_MOUNT_NOAC)
		sb->s_flags |= MS_SYNCHRONOUS;
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David Howells 已提交
535

536
	nfs_super_set_maxbytes(sb, server->maxfilesize);
D
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537 538 539
}

/*
540
 * Finish setting up an NFS2/3 superblock
D
David Howells 已提交
541
 */
542
static void nfs_fill_super(struct super_block *sb, struct nfs_mount_data *data)
D
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543 544
{
	struct nfs_server *server = NFS_SB(sb);
545

546 547 548 549
	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
550

551 552 553 554 555 556
	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;
557
	}
558 559 560

	sb->s_op = &nfs_sops;
 	nfs_initialise_sb(sb);
D
David Howells 已提交
561 562 563
}

/*
564
 * Finish setting up a cloned NFS2/3 superblock
D
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565
 */
566 567
static void nfs_clone_super(struct super_block *sb,
			    const struct super_block *old_sb)
D
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568
{
569 570 571 572 573
	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
574 575

	if (server->flags & NFS_MOUNT_VER3) {
576 577
		/* The VFS shouldn't apply the umask to mode bits. We will do
		 * so ourselves when necessary.
D
David Howells 已提交
578 579 580 581 582
		 */
		sb->s_flags |= MS_POSIXACL;
		sb->s_time_gran = 1;
	}

583 584
	sb->s_op = old_sb->s_op;
 	nfs_initialise_sb(sb);
D
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585 586
}

587
static int nfs_set_super(struct super_block *s, void *_server)
D
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588
{
589 590 591 592 593 594 595 596
	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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597 598 599 600
}

static int nfs_compare_super(struct super_block *sb, void *data)
{
601
	struct nfs_server *server = data, *old = NFS_SB(sb);
D
David Howells 已提交
602

603
	if (old->nfs_client != server->nfs_client)
D
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604
		return 0;
605
	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
D
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606
		return 0;
607
	return 1;
D
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608 609
}

610 611
static int nfs_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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612 613 614
{
	struct nfs_server *server = NULL;
	struct super_block *s;
615
	struct nfs_fh mntfh;
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616
	struct nfs_mount_data *data = raw_data;
617 618
	struct dentry *mntroot;
	int error;
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619

620 621 622 623
	/* Validate the mount data */
	error = nfs_validate_mount_data(data, &mntfh);
	if (error < 0)
		return error;
D
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624

625 626 627 628
	/* Get a volume representation */
	server = nfs_create_server(data, &mntfh);
	if (IS_ERR(server)) {
		error = PTR_ERR(server);
629
		goto out_err_noserver;
D
David Howells 已提交
630 631
	}

632
	/* Get a superblock - note that we may end up sharing one that already exists */
D
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633
	s = sget(fs_type, nfs_compare_super, nfs_set_super, server);
634 635
	if (IS_ERR(s)) {
		error = PTR_ERR(s);
636
		goto out_err_nosb;
637 638
	}

639 640 641 642
	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
	}
D
David Howells 已提交
643

644 645 646 647 648
	if (!s->s_root) {
		/* initial superblock/root creation */
		s->s_flags = flags;
		nfs_fill_super(s, data);
	}
D
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649

650 651 652 653
	mntroot = nfs_get_root(s, &mntfh);
	if (IS_ERR(mntroot)) {
		error = PTR_ERR(mntroot);
		goto error_splat_super;
D
David Howells 已提交
654
	}
655

656 657 658 659
	s->s_flags |= MS_ACTIVE;
	mnt->mnt_sb = s;
	mnt->mnt_root = mntroot;
	return 0;
660

661 662
out_err_nosb:
	nfs_free_server(server);
663 664
out_err_noserver:
	return error;
665 666 667 668 669

error_splat_super:
	up_write(&s->s_umount);
	deactivate_super(s);
	return error;
D
David Howells 已提交
670 671
}

672 673 674
/*
 * Destroy an NFS2/3 superblock
 */
D
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675 676 677 678 679
static void nfs_kill_super(struct super_block *s)
{
	struct nfs_server *server = NFS_SB(s);

	kill_anon_super(s);
680
	nfs_free_server(server);
D
David Howells 已提交
681 682
}

683 684 685 686 687 688
/*
 * 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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689 690
{
	struct nfs_clone_mount *data = raw_data;
691 692 693 694
	struct super_block *s;
	struct nfs_server *server;
	struct dentry *mntroot;
	int error;
D
David Howells 已提交
695

696
	dprintk("--> nfs_xdev_get_sb()\n");
D
David Howells 已提交
697

698 699 700 701 702 703
	/* 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;
	}
704

705 706 707 708 709 710
	/* 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;
	}
711

712 713 714
	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
D
David Howells 已提交
715
	}
716

717 718 719 720 721
	if (!s->s_root) {
		/* initial superblock/root creation */
		s->s_flags = flags;
		nfs_clone_super(s, data->sb);
	}
D
David Howells 已提交
722

723 724 725 726
	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
727 728
	}

729 730 731
	s->s_flags |= MS_ACTIVE;
	mnt->mnt_sb = s;
	mnt->mnt_root = mntroot;
D
David Howells 已提交
732

733 734
	dprintk("<-- nfs_xdev_get_sb() = 0\n");
	return 0;
735

736 737 738 739 740
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
741

742 743 744 745 746
error_splat_super:
	up_write(&s->s_umount);
	deactivate_super(s);
	dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
	return error;
D
David Howells 已提交
747 748
}

749 750
#ifdef CONFIG_NFS_V4

D
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751
/*
752
 * Finish setting up a cloned NFS4 superblock
D
David Howells 已提交
753
 */
754 755
static void nfs4_clone_super(struct super_block *sb,
			    const struct super_block *old_sb)
D
David Howells 已提交
756
{
757 758 759
	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
760
	sb->s_time_gran = 1;
761 762
	sb->s_op = old_sb->s_op;
 	nfs_initialise_sb(sb);
D
David Howells 已提交
763 764
}

765 766 767 768
/*
 * Set up an NFS4 superblock
 */
static void nfs4_fill_super(struct super_block *sb)
D
David Howells 已提交
769
{
770 771 772
	sb->s_time_gran = 1;
	sb->s_op = &nfs4_sops;
	nfs_initialise_sb(sb);
D
David Howells 已提交
773 774
}

775
static void *nfs_copy_user_string(char *dst, struct nfs_string *src, int maxlen)
D
David Howells 已提交
776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795
{
	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;
}

796 797 798
/*
 * Get the superblock for an NFS4 mountpoint
 */
799 800
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
801 802
{
	struct nfs4_mount_data *data = raw_data;
803 804 805 806 807 808 809
	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
810
	void *p;
811
	int error;
D
David Howells 已提交
812 813 814

	if (data == NULL) {
		dprintk("%s: missing data argument\n", __FUNCTION__);
815
		return -EINVAL;
D
David Howells 已提交
816 817 818
	}
	if (data->version <= 0 || data->version > NFS4_MOUNT_VERSION) {
		dprintk("%s: bad mount version\n", __FUNCTION__);
819
		return -EINVAL;
D
David Howells 已提交
820 821
	}

822 823 824 825 826 827 828 829 830 831 832 833 834 835
	/* 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;
	}
836 837
	/* RFC3530: The default port for NFS is 2049 */
	if (addr.sin_port == 0)
838
		addr.sin_port = htons(NFS_PORT);
839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855

	/* 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
856 857 858 859

	p = nfs_copy_user_string(NULL, &data->hostname, 256);
	if (IS_ERR(p))
		goto out_err;
860
	hostname = p;
D
David Howells 已提交
861 862 863 864

	p = nfs_copy_user_string(NULL, &data->mnt_path, 1024);
	if (IS_ERR(p))
		goto out_err;
865
	mntpath = p;
D
David Howells 已提交
866

867 868 869 870
	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
871 872 873
	if (IS_ERR(p))
		goto out_err;

874 875 876 877 878 879
	/* 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
880 881
	}

882 883
	/* 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);
884 885
	if (IS_ERR(s)) {
		error = PTR_ERR(s);
D
David Howells 已提交
886
		goto out_free;
887 888
	}

889 890 891 892 893
	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
	}

894 895 896 897 898
	if (!s->s_root) {
		/* initial superblock/root creation */
		s->s_flags = flags;
		nfs4_fill_super(s);
	}
D
David Howells 已提交
899

900 901 902 903
	mntroot = nfs4_get_root(s, &mntfh);
	if (IS_ERR(mntroot)) {
		error = PTR_ERR(mntroot);
		goto error_splat_super;
D
David Howells 已提交
904
	}
905

D
David Howells 已提交
906
	s->s_flags |= MS_ACTIVE;
907 908 909 910 911 912
	mnt->mnt_sb = s;
	mnt->mnt_root = mntroot;
	kfree(mntpath);
	kfree(hostname);
	return 0;

D
David Howells 已提交
913
out_err:
914
	error = PTR_ERR(p);
915 916
	goto out_err_noserver;

D
David Howells 已提交
917
out_free:
918 919 920 921
	nfs_free_server(server);
out_err_noserver:
	kfree(mntpath);
	kfree(hostname);
922
	return error;
923 924 925 926 927

error_splat_super:
	up_write(&s->s_umount);
	deactivate_super(s);
	goto out_err_noserver;
D
David Howells 已提交
928 929 930 931 932 933 934 935 936 937
}

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);
938
	nfs_free_server(server);
D
David Howells 已提交
939 940 941
}

/*
942
 * Clone an NFS4 server record on xdev traversal (FSID-change)
D
David Howells 已提交
943
 */
944 945 946
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
947
{
948 949 950 951 952
	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
953

954
	dprintk("--> nfs4_xdev_get_sb()\n");
D
David Howells 已提交
955

956 957 958 959 960
	/* 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
961 962
	}

963 964 965 966 967
	/* 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
968 969
	}

970 971 972 973
	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
	}
D
David Howells 已提交
974

975 976 977 978 979
	if (!s->s_root) {
		/* initial superblock/root creation */
		s->s_flags = flags;
		nfs4_clone_super(s, data->sb);
	}
D
David Howells 已提交
980

981 982 983 984 985
	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
986

987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004
	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
1005 1006
}

1007 1008 1009 1010 1011 1012
/*
 * 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
1013 1014
{
	struct nfs_clone_mount *data = raw_data;
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 1047
	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);
	}

1048
	mntroot = nfs4_get_root(s, &mntfh);
1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071
	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
1072 1073
}

1074
#endif /* CONFIG_NFS_V4 */