/*
   * fs/nfs/idmap.c
   *
   *  UID and GID to name mapping for clients.
   *
   *  Copyright (c) 2002 The Regents of the University of Michigan.
   *  All rights reserved.
   *
   *  Marius Aamodt Eriksen <marius@umich.edu>
   *
   *  Redistribution and use in source and binary forms, with or without
   *  modification, are permitted provided that the following conditions
   *  are met:
   *
   *  1. Redistributions of source code must retain the above copyright
   *     notice, this list of conditions and the following disclaimer.
   *  2. Redistributions in binary form must reproduce the above copyright
   *     notice, this list of conditions and the following disclaimer in the
   *     documentation and/or other materials provided with the distribution.
   *  3. Neither the name of the University nor the names of its
   *     contributors may be used to endorse or promote products derived
   *     from this software without specific prior written permission.
   *
   *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
   *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
   *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */

  #include <linux/types.h>

  #include <linux/parser.h>
  #include <linux/fs.h>

  #include <linux/nfs_idmap.h>

  #include <net/net_namespace.h>
  #include <linux/sunrpc/rpc_pipe_fs.h>

  #include <linux/nfs_fs.h>

  #include <linux/nfs_fs_sb.h>

  #include <linux/key.h>

  #include <linux/keyctl.h>
  #include <linux/key-type.h>

  #include <keys/user-type.h>

  #include <linux/module.h>

  #include "internal.h"

  #include "netns.h"

  #include "nfs4trace.h"

  
  #define NFS_UINT_MAXLEN 11

  static const struct cred *id_resolver_cache;
  static struct key_type key_type_id_resolver_legacy;

  struct idmap_legacy_upcalldata {
  	struct rpc_pipe_msg pipe_msg;
  	struct idmap_msg idmap_msg;

  	struct key_construction	*key_cons;

  	struct idmap *idmap;
  };

  struct idmap {

  	struct rpc_pipe_dir_object idmap_pdo;

  	struct rpc_pipe		*idmap_pipe;
  	struct idmap_legacy_upcalldata *idmap_upcall_data;
  	struct mutex		idmap_mutex;
  };

  /**
   * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
   * @fattr: fully initialised struct nfs_fattr
   * @owner_name: owner name string cache
   * @group_name: group name string cache
   */
  void nfs_fattr_init_names(struct nfs_fattr *fattr,
  		struct nfs4_string *owner_name,
  		struct nfs4_string *group_name)
  {
  	fattr->owner_name = owner_name;
  	fattr->group_name = group_name;
  }
  
  static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
  {
  	fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
  	kfree(fattr->owner_name->data);
  }
  
  static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
  {
  	fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
  	kfree(fattr->group_name->data);
  }
  
  static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
  {
  	struct nfs4_string *owner = fattr->owner_name;

  	kuid_t uid;

  
  	if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
  		return false;
  	if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
  		fattr->uid = uid;
  		fattr->valid |= NFS_ATTR_FATTR_OWNER;
  	}
  	return true;
  }
  
  static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
  {
  	struct nfs4_string *group = fattr->group_name;

  	kgid_t gid;

  
  	if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
  		return false;
  	if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
  		fattr->gid = gid;
  		fattr->valid |= NFS_ATTR_FATTR_GROUP;
  	}
  	return true;
  }
  
  /**
   * nfs_fattr_free_names - free up the NFSv4 owner and group strings
   * @fattr: a fully initialised nfs_fattr structure
   */
  void nfs_fattr_free_names(struct nfs_fattr *fattr)
  {
  	if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
  		nfs_fattr_free_owner_name(fattr);
  	if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
  		nfs_fattr_free_group_name(fattr);
  }
  
  /**
   * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
   * @server: pointer to the filesystem nfs_server structure
   * @fattr: a fully initialised nfs_fattr structure
   *
   * This helper maps the cached NFSv4 owner/group strings in fattr into
   * their numeric uid/gid equivalents, and then frees the cached strings.
   */
  void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
  {
  	if (nfs_fattr_map_owner_name(server, fattr))
  		nfs_fattr_free_owner_name(fattr);
  	if (nfs_fattr_map_group_name(server, fattr))
  		nfs_fattr_free_group_name(fattr);
  }

  
  static int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
  {
  	unsigned long val;
  	char buf[16];
  
  	if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
  		return 0;
  	memcpy(buf, name, namelen);
  	buf[namelen] = '\0';

  	if (kstrtoul(buf, 0, &val) != 0)

  		return 0;
  	*res = val;
  	return 1;
  }

  static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
  {
  	return snprintf(buf, buflen, "%u", id);
  }

  static struct key_type key_type_id_resolver = {

  	.name		= "id_resolver",

  	.preparse	= user_preparse,
  	.free_preparse	= user_free_preparse,
  	.instantiate	= generic_key_instantiate,

  	.revoke		= user_revoke,
  	.destroy	= user_destroy,
  	.describe	= user_describe,
  	.read		= user_read,
  };

  static int nfs_idmap_init_keyring(void)

  {
  	struct cred *cred;
  	struct key *keyring;
  	int ret = 0;

  	printk(KERN_NOTICE "NFS: Registering the %s key type
  ",
  		key_type_id_resolver.name);

  
  	cred = prepare_kernel_cred(NULL);
  	if (!cred)
  		return -ENOMEM;

  	keyring = keyring_alloc(".id_resolver",
  				GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,

  				(KEY_POS_ALL & ~KEY_POS_SETATTR) |
  				KEY_USR_VIEW | KEY_USR_READ,
  				KEY_ALLOC_NOT_IN_QUOTA, NULL);

  	if (IS_ERR(keyring)) {
  		ret = PTR_ERR(keyring);
  		goto failed_put_cred;
  	}

  	ret = register_key_type(&key_type_id_resolver);
  	if (ret < 0)
  		goto failed_put_key;

  	ret = register_key_type(&key_type_id_resolver_legacy);
  	if (ret < 0)
  		goto failed_reg_legacy;

  	set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);

  	cred->thread_keyring = keyring;
  	cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
  	id_resolver_cache = cred;
  	return 0;

  failed_reg_legacy:
  	unregister_key_type(&key_type_id_resolver);

  failed_put_key:
  	key_put(keyring);
  failed_put_cred:
  	put_cred(cred);
  	return ret;
  }

  static void nfs_idmap_quit_keyring(void)

  {
  	key_revoke(id_resolver_cache->thread_keyring);
  	unregister_key_type(&key_type_id_resolver);

  	unregister_key_type(&key_type_id_resolver_legacy);

  	put_cred(id_resolver_cache);
  }
  
  /*
   * Assemble the description to pass to request_key()
   * This function will allocate a new string and update dest to point
   * at it.  The caller is responsible for freeing dest.
   *
   * On error 0 is returned.  Otherwise, the length of dest is returned.
   */
  static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
  				const char *type, size_t typelen, char **desc)
  {
  	char *cp;
  	size_t desclen = typelen + namelen + 2;
  
  	*desc = kmalloc(desclen, GFP_KERNEL);

  	if (!*desc)

  		return -ENOMEM;
  
  	cp = *desc;
  	memcpy(cp, type, typelen);
  	cp += typelen;
  	*cp++ = ':';
  
  	memcpy(cp, name, namelen);
  	cp += namelen;
  	*cp = '\0';
  	return desclen;
  }

  static struct key *nfs_idmap_request_key(const char *name, size_t namelen,
  					 const char *type, struct idmap *idmap)

  {

  	char *desc;

  	struct key *rkey;

  	ssize_t ret;
  
  	ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
  	if (ret <= 0)

  		return ERR_PTR(ret);
  
  	rkey = request_key(&key_type_id_resolver, desc, "");
  	if (IS_ERR(rkey)) {
  		mutex_lock(&idmap->idmap_mutex);
  		rkey = request_key_with_auxdata(&key_type_id_resolver_legacy,
  						desc, "", 0, idmap);
  		mutex_unlock(&idmap->idmap_mutex);
  	}

  	if (!IS_ERR(rkey))
  		set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags);

  
  	kfree(desc);
  	return rkey;
  }
  
  static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
  				 const char *type, void *data,
  				 size_t data_size, struct idmap *idmap)
  {
  	const struct cred *saved_cred;
  	struct key *rkey;
  	struct user_key_payload *payload;
  	ssize_t ret;

  
  	saved_cred = override_creds(id_resolver_cache);

  	rkey = nfs_idmap_request_key(name, namelen, type, idmap);

  	revert_creds(saved_cred);

  	if (IS_ERR(rkey)) {
  		ret = PTR_ERR(rkey);
  		goto out;
  	}
  
  	rcu_read_lock();
  	rkey->perm |= KEY_USR_VIEW;
  
  	ret = key_validate(rkey);
  	if (ret < 0)
  		goto out_up;

  	payload = rcu_dereference(rkey->payload.rcudata);

  	if (IS_ERR_OR_NULL(payload)) {
  		ret = PTR_ERR(payload);
  		goto out_up;
  	}
  
  	ret = payload->datalen;
  	if (ret > 0 && ret <= data_size)
  		memcpy(data, payload->data, ret);
  	else
  		ret = -EINVAL;
  
  out_up:
  	rcu_read_unlock();
  	key_put(rkey);
  out:
  	return ret;
  }

  /* ID -> Name */

  static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
  				     size_t buflen, struct idmap *idmap)

  {
  	char id_str[NFS_UINT_MAXLEN];
  	int id_len;
  	ssize_t ret;
  
  	id_len = snprintf(id_str, sizeof(id_str), "%u", id);

  	ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);

  	if (ret < 0)
  		return -EINVAL;
  	return ret;
  }
  
  /* Name -> ID */

  static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
  			       __u32 *id, struct idmap *idmap)

  {
  	char id_str[NFS_UINT_MAXLEN];
  	long id_long;
  	ssize_t data_size;
  	int ret = 0;

  	data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);

  	if (data_size <= 0) {
  		ret = -EINVAL;
  	} else {

  		ret = kstrtol(id_str, 10, &id_long);

  		*id = (__u32)id_long;
  	}
  	return ret;
  }

  /* idmap classic begins here */

  enum {
  	Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err

  };

  static const match_table_t nfs_idmap_tokens = {
  	{ Opt_find_uid, "uid:%s" },
  	{ Opt_find_gid, "gid:%s" },
  	{ Opt_find_user, "user:%s" },
  	{ Opt_find_group, "group:%s" },
  	{ Opt_find_err, NULL }

  };

  static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);

  static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
  				   size_t);

  static void idmap_release_pipe(struct inode *);

  static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);

  static const struct rpc_pipe_ops idmap_upcall_ops = {

  	.upcall		= rpc_pipe_generic_upcall,

  	.downcall	= idmap_pipe_downcall,

  	.release_pipe	= idmap_release_pipe,

  	.destroy_msg	= idmap_pipe_destroy_msg,

  };

  static struct key_type key_type_id_resolver_legacy = {

  	.name		= "id_legacy",

  	.preparse	= user_preparse,
  	.free_preparse	= user_free_preparse,
  	.instantiate	= generic_key_instantiate,

  	.revoke		= user_revoke,
  	.destroy	= user_destroy,
  	.describe	= user_describe,
  	.read		= user_read,
  	.request_key	= nfs_idmap_legacy_upcall,
  };

  static void nfs_idmap_pipe_destroy(struct dentry *dir,
  		struct rpc_pipe_dir_object *pdo)

  {

  	struct idmap *idmap = pdo->pdo_data;
  	struct rpc_pipe *pipe = idmap->idmap_pipe;

  	if (pipe->dentry) {

  		rpc_unlink(pipe->dentry);

  		pipe->dentry = NULL;
  	}

  }

  static int nfs_idmap_pipe_create(struct dentry *dir,
  		struct rpc_pipe_dir_object *pdo)

  {

  	struct idmap *idmap = pdo->pdo_data;
  	struct rpc_pipe *pipe = idmap->idmap_pipe;

  	struct dentry *dentry;
  
  	dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
  	if (IS_ERR(dentry))
  		return PTR_ERR(dentry);
  	pipe->dentry = dentry;
  	return 0;
  }

  static const struct rpc_pipe_dir_object_ops nfs_idmap_pipe_dir_object_ops = {
  	.create = nfs_idmap_pipe_create,
  	.destroy = nfs_idmap_pipe_destroy,
  };

  int

  nfs_idmap_new(struct nfs_client *clp)

  {
  	struct idmap *idmap;

  	struct rpc_pipe *pipe;

  	int error;

  	idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
  	if (idmap == NULL)
  		return -ENOMEM;

  	rpc_init_pipe_dir_object(&idmap->idmap_pdo,
  			&nfs_idmap_pipe_dir_object_ops,
  			idmap);

  	pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
  	if (IS_ERR(pipe)) {
  		error = PTR_ERR(pipe);

  		goto err;

  	}
  	idmap->idmap_pipe = pipe;

  	mutex_init(&idmap->idmap_mutex);

  	error = rpc_add_pipe_dir_object(clp->cl_net,
  			&clp->cl_rpcclient->cl_pipedir_objects,
  			&idmap->idmap_pdo);
  	if (error)
  		goto err_destroy_pipe;

  	clp->cl_idmap = idmap;

  	return 0;

  err_destroy_pipe:
  	rpc_destroy_pipe_data(idmap->idmap_pipe);
  err:
  	kfree(idmap);
  	return error;

  }
  
  void

  nfs_idmap_delete(struct nfs_client *clp)

  {
  	struct idmap *idmap = clp->cl_idmap;
  
  	if (!idmap)
  		return;

  	clp->cl_idmap = NULL;

  	rpc_remove_pipe_dir_object(clp->cl_net,
  			&clp->cl_rpcclient->cl_pipedir_objects,
  			&idmap->idmap_pdo);
  	rpc_destroy_pipe_data(idmap->idmap_pipe);

  	kfree(idmap);
  }

  int nfs_idmap_init(void)

  {

  	int ret;
  	ret = nfs_idmap_init_keyring();
  	if (ret != 0)
  		goto out;

  out:
  	return ret;

  }

  void nfs_idmap_quit(void)

  {

  	nfs_idmap_quit_keyring();

  }

  static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
  				     struct idmap_msg *im,

  				     struct rpc_pipe_msg *msg)

  {

  	substring_t substr;
  	int token, ret;

  	im->im_type = IDMAP_TYPE_GROUP;
  	token = match_token(desc, nfs_idmap_tokens, &substr);

  	switch (token) {
  	case Opt_find_uid:
  		im->im_type = IDMAP_TYPE_USER;
  	case Opt_find_gid:
  		im->im_conv = IDMAP_CONV_NAMETOID;
  		ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
  		break;

  	case Opt_find_user:
  		im->im_type = IDMAP_TYPE_USER;
  	case Opt_find_group:
  		im->im_conv = IDMAP_CONV_IDTONAME;
  		ret = match_int(&substr, &im->im_id);
  		break;

  	default:
  		ret = -EINVAL;

  		goto out;
  	}

  	msg->data = im;
  	msg->len  = sizeof(struct idmap_msg);

  out:

  	return ret;

  }

  static bool
  nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,

  		struct idmap_legacy_upcalldata *data)

  {

  	if (idmap->idmap_upcall_data != NULL) {

  		WARN_ON_ONCE(1);
  		return false;
  	}

  	idmap->idmap_upcall_data = data;

  	return true;
  }
  
  static void
  nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
  {

  	struct key_construction *cons = idmap->idmap_upcall_data->key_cons;

  	kfree(idmap->idmap_upcall_data);
  	idmap->idmap_upcall_data = NULL;

  	complete_request_key(cons, ret);
  }
  
  static void
  nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
  {

  	if (idmap->idmap_upcall_data != NULL)

  		nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
  }

  static int nfs_idmap_legacy_upcall(struct key_construction *cons,
  				   const char *op,
  				   void *aux)

  {

  	struct idmap_legacy_upcalldata *data;

  	struct rpc_pipe_msg *msg;

  	struct idmap_msg *im;

  	struct idmap *idmap = (struct idmap *)aux;
  	struct key *key = cons->key;

  	int ret = -ENOMEM;

  	/* msg and im are freed in idmap_pipe_destroy_msg */

  	data = kzalloc(sizeof(*data), GFP_KERNEL);

  	if (!data)

  		goto out1;

  	msg = &data->pipe_msg;
  	im = &data->idmap_msg;
  	data->idmap = idmap;

  	data->key_cons = cons;

  
  	ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);

  	if (ret < 0)
  		goto out2;

  	ret = -EAGAIN;

  	if (!nfs_idmap_prepare_pipe_upcall(idmap, data))

  		goto out2;

  	ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
  	if (ret < 0)

  		nfs_idmap_abort_pipe_upcall(idmap, ret);

  	return ret;

  out2:

  	kfree(data);

  out1:

  	complete_request_key(cons, ret);

  	return ret;

  }

  static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data, size_t datalen)

  {

  	return key_instantiate_and_link(key, data, datalen,

  					id_resolver_cache->thread_keyring,
  					authkey);
  }

  static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
  		struct idmap_msg *upcall,
  		struct key *key, struct key *authkey)

  {
  	char id_str[NFS_UINT_MAXLEN];

  	size_t len;

  	int ret = -ENOKEY;

  	/* ret = -ENOKEY */
  	if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
  		goto out;

  	switch (im->im_conv) {
  	case IDMAP_CONV_NAMETOID:

  		if (strcmp(upcall->im_name, im->im_name) != 0)
  			break;

  		/* Note: here we store the NUL terminator too */
  		len = sprintf(id_str, "%d", im->im_id) + 1;
  		ret = nfs_idmap_instantiate(key, authkey, id_str, len);

  		break;
  	case IDMAP_CONV_IDTONAME:

  		if (upcall->im_id != im->im_id)
  			break;

  		len = strlen(im->im_name);
  		ret = nfs_idmap_instantiate(key, authkey, im->im_name, len);

  		break;

  	default:
  		ret = -EINVAL;

  	}

  out:

  	return ret;
  }

  static ssize_t
  idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
  {

  	struct rpc_inode *rpci = RPC_I(file_inode(filp));

  	struct idmap *idmap = (struct idmap *)rpci->private;

  	struct key_construction *cons;

  	struct idmap_msg im;

  	size_t namelen_in;

  	int ret = -ENOKEY;

  	/* If instantiation is successful, anyone waiting for key construction
  	 * will have been woken up and someone else may now have used
  	 * idmap_key_cons - so after this point we may no longer touch it.
  	 */

  	if (idmap->idmap_upcall_data == NULL)

  		goto out_noupcall;

  	cons = idmap->idmap_upcall_data->key_cons;

  	if (mlen != sizeof(im)) {
  		ret = -ENOSPC;

  		goto out;
  	}

  	if (copy_from_user(&im, src, mlen) != 0) {
  		ret = -EFAULT;

  		goto out;

  	}

  	if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {

  		ret = -ENOKEY;
  		goto out;

  	}

  	namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
  	if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
  		ret = -EINVAL;

  		goto out;

  }

  	ret = nfs_idmap_read_and_verify_message(&im,
  			&idmap->idmap_upcall_data->idmap_msg,
  			cons->key, cons->authkey);

  	if (ret >= 0) {
  		key_set_timeout(cons->key, nfs_idmap_cache_timeout);
  		ret = mlen;
  	}

  out:

  	nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
  out_noupcall:

  	return ret;
  }

  static void

  idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
  {

  	struct idmap_legacy_upcalldata *data = container_of(msg,
  			struct idmap_legacy_upcalldata,
  			pipe_msg);
  	struct idmap *idmap = data->idmap;

  
  	if (msg->errno)
  		nfs_idmap_abort_pipe_upcall(idmap, msg->errno);

  }
  
  static void
  idmap_release_pipe(struct inode *inode)
  {
  	struct rpc_inode *rpci = RPC_I(inode);
  	struct idmap *idmap = (struct idmap *)rpci->private;

  
  	nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);

  }

  int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, kuid_t *uid)

  {

  	struct idmap *idmap = server->nfs_client->cl_idmap;

  	__u32 id = -1;
  	int ret = 0;

  	if (!nfs_map_string_to_numeric(name, namelen, &id))
  		ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap);
  	if (ret == 0) {
  		*uid = make_kuid(&init_user_ns, id);
  		if (!uid_valid(*uid))
  			ret = -ERANGE;
  	}

  	trace_nfs4_map_name_to_uid(name, namelen, id, ret);

  	return ret;

  }

  int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, kgid_t *gid)

  {

  	struct idmap *idmap = server->nfs_client->cl_idmap;

  	__u32 id = -1;
  	int ret = 0;

  	if (!nfs_map_string_to_numeric(name, namelen, &id))
  		ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap);
  	if (ret == 0) {
  		*gid = make_kgid(&init_user_ns, id);
  		if (!gid_valid(*gid))
  			ret = -ERANGE;
  	}

  	trace_nfs4_map_group_to_gid(name, namelen, id, ret);

  	return ret;

  }

  int nfs_map_uid_to_name(const struct nfs_server *server, kuid_t uid, char *buf, size_t buflen)

  {

  	struct idmap *idmap = server->nfs_client->cl_idmap;

  	int ret = -EINVAL;

  	__u32 id;

  	id = from_kuid(&init_user_ns, uid);

  	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))

  		ret = nfs_idmap_lookup_name(id, "user", buf, buflen, idmap);

  	if (ret < 0)

  		ret = nfs_map_numeric_to_string(id, buf, buflen);

  	trace_nfs4_map_uid_to_name(buf, ret, id, ret);

  	return ret;

  }

  int nfs_map_gid_to_group(const struct nfs_server *server, kgid_t gid, char *buf, size_t buflen)

  {

  	struct idmap *idmap = server->nfs_client->cl_idmap;

  	int ret = -EINVAL;

  	__u32 id;

  	id = from_kgid(&init_user_ns, gid);

  	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))

  		ret = nfs_idmap_lookup_name(id, "group", buf, buflen, idmap);

  	if (ret < 0)

  		ret = nfs_map_numeric_to_string(id, buf, buflen);

  	trace_nfs4_map_gid_to_group(buf, ret, id, ret);

  	return ret;

  }