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518 lines
13 KiB
C
518 lines
13 KiB
C
/*
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* fs/nfs/idmap.c
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*
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* UID and GID to name mapping for clients.
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*
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* Copyright (c) 2002 The Regents of the University of Michigan.
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* All rights reserved.
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*
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* Marius Aamodt Eriksen <marius@umich.edu>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/socket.h>
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#include <linux/in.h>
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#include <linux/sched.h>
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#include <linux/sunrpc/clnt.h>
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#include <linux/workqueue.h>
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#include <linux/sunrpc/rpc_pipe_fs.h>
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#include <linux/nfs_fs.h>
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#include <linux/nfs_idmap.h>
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#include "nfs4_fs.h"
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#define IDMAP_HASH_SZ 128
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/* Default cache timeout is 10 minutes */
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unsigned int nfs_idmap_cache_timeout = 600 * HZ;
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static int param_set_idmap_timeout(const char *val, struct kernel_param *kp)
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{
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char *endp;
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int num = simple_strtol(val, &endp, 0);
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int jif = num * HZ;
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if (endp == val || *endp || num < 0 || jif < num)
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return -EINVAL;
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*((int *)kp->arg) = jif;
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return 0;
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}
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module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int,
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&nfs_idmap_cache_timeout, 0644);
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struct idmap_hashent {
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unsigned long ih_expires;
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__u32 ih_id;
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size_t ih_namelen;
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char ih_name[IDMAP_NAMESZ];
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};
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struct idmap_hashtable {
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__u8 h_type;
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struct idmap_hashent h_entries[IDMAP_HASH_SZ];
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};
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struct idmap {
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struct dentry *idmap_dentry;
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wait_queue_head_t idmap_wq;
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struct idmap_msg idmap_im;
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struct mutex idmap_lock; /* Serializes upcalls */
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struct mutex idmap_im_lock; /* Protects the hashtable */
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struct idmap_hashtable idmap_user_hash;
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struct idmap_hashtable idmap_group_hash;
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};
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static ssize_t idmap_pipe_upcall(struct file *, struct rpc_pipe_msg *,
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char __user *, size_t);
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static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
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size_t);
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static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
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static unsigned int fnvhash32(const void *, size_t);
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static const struct rpc_pipe_ops idmap_upcall_ops = {
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.upcall = idmap_pipe_upcall,
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.downcall = idmap_pipe_downcall,
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.destroy_msg = idmap_pipe_destroy_msg,
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};
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int
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nfs_idmap_new(struct nfs_client *clp)
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{
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struct idmap *idmap;
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int error;
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BUG_ON(clp->cl_idmap != NULL);
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idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
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if (idmap == NULL)
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return -ENOMEM;
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idmap->idmap_dentry = rpc_mkpipe(clp->cl_rpcclient->cl_path.dentry,
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"idmap", idmap, &idmap_upcall_ops, 0);
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if (IS_ERR(idmap->idmap_dentry)) {
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error = PTR_ERR(idmap->idmap_dentry);
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kfree(idmap);
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return error;
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}
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mutex_init(&idmap->idmap_lock);
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mutex_init(&idmap->idmap_im_lock);
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init_waitqueue_head(&idmap->idmap_wq);
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idmap->idmap_user_hash.h_type = IDMAP_TYPE_USER;
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idmap->idmap_group_hash.h_type = IDMAP_TYPE_GROUP;
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clp->cl_idmap = idmap;
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return 0;
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}
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void
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nfs_idmap_delete(struct nfs_client *clp)
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{
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struct idmap *idmap = clp->cl_idmap;
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if (!idmap)
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return;
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rpc_unlink(idmap->idmap_dentry);
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clp->cl_idmap = NULL;
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kfree(idmap);
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}
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/*
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* Helper routines for manipulating the hashtable
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*/
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static inline struct idmap_hashent *
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idmap_name_hash(struct idmap_hashtable* h, const char *name, size_t len)
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{
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return &h->h_entries[fnvhash32(name, len) % IDMAP_HASH_SZ];
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}
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static struct idmap_hashent *
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idmap_lookup_name(struct idmap_hashtable *h, const char *name, size_t len)
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{
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struct idmap_hashent *he = idmap_name_hash(h, name, len);
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if (he->ih_namelen != len || memcmp(he->ih_name, name, len) != 0)
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return NULL;
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if (time_after(jiffies, he->ih_expires))
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return NULL;
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return he;
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}
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static inline struct idmap_hashent *
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idmap_id_hash(struct idmap_hashtable* h, __u32 id)
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{
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return &h->h_entries[fnvhash32(&id, sizeof(id)) % IDMAP_HASH_SZ];
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}
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static struct idmap_hashent *
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idmap_lookup_id(struct idmap_hashtable *h, __u32 id)
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{
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struct idmap_hashent *he = idmap_id_hash(h, id);
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if (he->ih_id != id || he->ih_namelen == 0)
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return NULL;
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if (time_after(jiffies, he->ih_expires))
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return NULL;
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return he;
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}
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/*
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* Routines for allocating new entries in the hashtable.
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* For now, we just have 1 entry per bucket, so it's all
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* pretty trivial.
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*/
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static inline struct idmap_hashent *
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idmap_alloc_name(struct idmap_hashtable *h, char *name, size_t len)
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{
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return idmap_name_hash(h, name, len);
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}
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static inline struct idmap_hashent *
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idmap_alloc_id(struct idmap_hashtable *h, __u32 id)
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{
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return idmap_id_hash(h, id);
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}
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static void
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idmap_update_entry(struct idmap_hashent *he, const char *name,
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size_t namelen, __u32 id)
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{
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he->ih_id = id;
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memcpy(he->ih_name, name, namelen);
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he->ih_name[namelen] = '\0';
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he->ih_namelen = namelen;
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he->ih_expires = jiffies + nfs_idmap_cache_timeout;
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}
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/*
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* Name -> ID
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*/
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static int
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nfs_idmap_id(struct idmap *idmap, struct idmap_hashtable *h,
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const char *name, size_t namelen, __u32 *id)
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{
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struct rpc_pipe_msg msg;
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struct idmap_msg *im;
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struct idmap_hashent *he;
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DECLARE_WAITQUEUE(wq, current);
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int ret = -EIO;
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im = &idmap->idmap_im;
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/*
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* String sanity checks
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* Note that the userland daemon expects NUL terminated strings
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*/
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for (;;) {
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if (namelen == 0)
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return -EINVAL;
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if (name[namelen-1] != '\0')
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break;
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namelen--;
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}
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if (namelen >= IDMAP_NAMESZ)
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return -EINVAL;
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mutex_lock(&idmap->idmap_lock);
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mutex_lock(&idmap->idmap_im_lock);
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he = idmap_lookup_name(h, name, namelen);
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if (he != NULL) {
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*id = he->ih_id;
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ret = 0;
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goto out;
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}
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memset(im, 0, sizeof(*im));
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memcpy(im->im_name, name, namelen);
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im->im_type = h->h_type;
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im->im_conv = IDMAP_CONV_NAMETOID;
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memset(&msg, 0, sizeof(msg));
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msg.data = im;
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msg.len = sizeof(*im);
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add_wait_queue(&idmap->idmap_wq, &wq);
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if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
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remove_wait_queue(&idmap->idmap_wq, &wq);
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goto out;
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}
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set_current_state(TASK_UNINTERRUPTIBLE);
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mutex_unlock(&idmap->idmap_im_lock);
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schedule();
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__set_current_state(TASK_RUNNING);
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remove_wait_queue(&idmap->idmap_wq, &wq);
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mutex_lock(&idmap->idmap_im_lock);
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if (im->im_status & IDMAP_STATUS_SUCCESS) {
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*id = im->im_id;
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ret = 0;
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}
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out:
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memset(im, 0, sizeof(*im));
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mutex_unlock(&idmap->idmap_im_lock);
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mutex_unlock(&idmap->idmap_lock);
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return ret;
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}
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/*
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* ID -> Name
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*/
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static int
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nfs_idmap_name(struct idmap *idmap, struct idmap_hashtable *h,
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__u32 id, char *name)
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{
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struct rpc_pipe_msg msg;
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struct idmap_msg *im;
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struct idmap_hashent *he;
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DECLARE_WAITQUEUE(wq, current);
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int ret = -EIO;
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unsigned int len;
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im = &idmap->idmap_im;
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mutex_lock(&idmap->idmap_lock);
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mutex_lock(&idmap->idmap_im_lock);
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he = idmap_lookup_id(h, id);
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if (he) {
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memcpy(name, he->ih_name, he->ih_namelen);
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ret = he->ih_namelen;
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goto out;
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}
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memset(im, 0, sizeof(*im));
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im->im_type = h->h_type;
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im->im_conv = IDMAP_CONV_IDTONAME;
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im->im_id = id;
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memset(&msg, 0, sizeof(msg));
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msg.data = im;
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msg.len = sizeof(*im);
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add_wait_queue(&idmap->idmap_wq, &wq);
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if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
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remove_wait_queue(&idmap->idmap_wq, &wq);
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goto out;
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}
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set_current_state(TASK_UNINTERRUPTIBLE);
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mutex_unlock(&idmap->idmap_im_lock);
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schedule();
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__set_current_state(TASK_RUNNING);
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remove_wait_queue(&idmap->idmap_wq, &wq);
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mutex_lock(&idmap->idmap_im_lock);
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if (im->im_status & IDMAP_STATUS_SUCCESS) {
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if ((len = strnlen(im->im_name, IDMAP_NAMESZ)) == 0)
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goto out;
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memcpy(name, im->im_name, len);
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ret = len;
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}
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out:
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memset(im, 0, sizeof(*im));
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mutex_unlock(&idmap->idmap_im_lock);
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mutex_unlock(&idmap->idmap_lock);
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return ret;
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}
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/* RPC pipefs upcall/downcall routines */
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static ssize_t
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idmap_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
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char __user *dst, size_t buflen)
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{
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char *data = (char *)msg->data + msg->copied;
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size_t mlen = min(msg->len, buflen);
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unsigned long left;
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left = copy_to_user(dst, data, mlen);
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if (left == mlen) {
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msg->errno = -EFAULT;
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return -EFAULT;
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}
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mlen -= left;
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msg->copied += mlen;
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msg->errno = 0;
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return mlen;
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}
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static ssize_t
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idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
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{
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struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
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struct idmap *idmap = (struct idmap *)rpci->private;
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struct idmap_msg im_in, *im = &idmap->idmap_im;
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struct idmap_hashtable *h;
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struct idmap_hashent *he = NULL;
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size_t namelen_in;
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int ret;
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if (mlen != sizeof(im_in))
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return -ENOSPC;
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if (copy_from_user(&im_in, src, mlen) != 0)
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return -EFAULT;
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mutex_lock(&idmap->idmap_im_lock);
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ret = mlen;
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im->im_status = im_in.im_status;
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/* If we got an error, terminate now, and wake up pending upcalls */
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if (!(im_in.im_status & IDMAP_STATUS_SUCCESS)) {
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wake_up(&idmap->idmap_wq);
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goto out;
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}
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/* Sanity checking of strings */
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ret = -EINVAL;
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namelen_in = strnlen(im_in.im_name, IDMAP_NAMESZ);
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if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ)
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goto out;
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switch (im_in.im_type) {
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case IDMAP_TYPE_USER:
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h = &idmap->idmap_user_hash;
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break;
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case IDMAP_TYPE_GROUP:
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h = &idmap->idmap_group_hash;
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break;
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default:
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goto out;
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}
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switch (im_in.im_conv) {
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case IDMAP_CONV_IDTONAME:
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/* Did we match the current upcall? */
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if (im->im_conv == IDMAP_CONV_IDTONAME
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&& im->im_type == im_in.im_type
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&& im->im_id == im_in.im_id) {
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/* Yes: copy string, including the terminating '\0' */
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memcpy(im->im_name, im_in.im_name, namelen_in);
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im->im_name[namelen_in] = '\0';
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wake_up(&idmap->idmap_wq);
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}
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he = idmap_alloc_id(h, im_in.im_id);
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break;
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case IDMAP_CONV_NAMETOID:
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/* Did we match the current upcall? */
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if (im->im_conv == IDMAP_CONV_NAMETOID
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&& im->im_type == im_in.im_type
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&& strnlen(im->im_name, IDMAP_NAMESZ) == namelen_in
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&& memcmp(im->im_name, im_in.im_name, namelen_in) == 0) {
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im->im_id = im_in.im_id;
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wake_up(&idmap->idmap_wq);
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}
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he = idmap_alloc_name(h, im_in.im_name, namelen_in);
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break;
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default:
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goto out;
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}
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/* If the entry is valid, also copy it to the cache */
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if (he != NULL)
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idmap_update_entry(he, im_in.im_name, namelen_in, im_in.im_id);
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ret = mlen;
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out:
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mutex_unlock(&idmap->idmap_im_lock);
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return ret;
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}
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static void
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idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
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{
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struct idmap_msg *im = msg->data;
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struct idmap *idmap = container_of(im, struct idmap, idmap_im);
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if (msg->errno >= 0)
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return;
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mutex_lock(&idmap->idmap_im_lock);
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im->im_status = IDMAP_STATUS_LOOKUPFAIL;
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wake_up(&idmap->idmap_wq);
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mutex_unlock(&idmap->idmap_im_lock);
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}
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/*
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* Fowler/Noll/Vo hash
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* http://www.isthe.com/chongo/tech/comp/fnv/
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*/
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#define FNV_P_32 ((unsigned int)0x01000193) /* 16777619 */
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#define FNV_1_32 ((unsigned int)0x811c9dc5) /* 2166136261 */
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static unsigned int fnvhash32(const void *buf, size_t buflen)
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{
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const unsigned char *p, *end = (const unsigned char *)buf + buflen;
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unsigned int hash = FNV_1_32;
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for (p = buf; p < end; p++) {
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hash *= FNV_P_32;
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hash ^= (unsigned int)*p;
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}
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return hash;
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}
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int nfs_map_name_to_uid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *uid)
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{
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struct idmap *idmap = clp->cl_idmap;
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return nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
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}
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int nfs_map_group_to_gid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *uid)
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{
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struct idmap *idmap = clp->cl_idmap;
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return nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, uid);
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}
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int nfs_map_uid_to_name(struct nfs_client *clp, __u32 uid, char *buf)
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{
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struct idmap *idmap = clp->cl_idmap;
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return nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
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}
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int nfs_map_gid_to_group(struct nfs_client *clp, __u32 uid, char *buf)
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{
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struct idmap *idmap = clp->cl_idmap;
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return nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
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}
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