watchdog: iTCO_wdt.c: remove extra pci_dev_put()'s from init code
[pandora-kernel.git] / fs / nfs / idmap.c
1 /*
2  * fs/nfs/idmap.c
3  *
4  *  UID and GID to name mapping for clients.
5  *
6  *  Copyright (c) 2002 The Regents of the University of Michigan.
7  *  All rights reserved.
8  *
9  *  Marius Aamodt Eriksen <marius@umich.edu>
10  *
11  *  Redistribution and use in source and binary forms, with or without
12  *  modification, are permitted provided that the following conditions
13  *  are met:
14  *
15  *  1. Redistributions of source code must retain the above copyright
16  *     notice, this list of conditions and the following disclaimer.
17  *  2. Redistributions in binary form must reproduce the above copyright
18  *     notice, this list of conditions and the following disclaimer in the
19  *     documentation and/or other materials provided with the distribution.
20  *  3. Neither the name of the University nor the names of its
21  *     contributors may be used to endorse or promote products derived
22  *     from this software without specific prior written permission.
23  *
24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  */
36
37 #ifdef CONFIG_NFS_USE_NEW_IDMAPPER
38
39 #include <linux/slab.h>
40 #include <linux/cred.h>
41 #include <linux/nfs_idmap.h>
42 #include <linux/keyctl.h>
43 #include <linux/key-type.h>
44 #include <linux/rcupdate.h>
45 #include <linux/kernel.h>
46 #include <linux/err.h>
47
48 #include <keys/user-type.h>
49
50 #define NFS_UINT_MAXLEN 11
51
52 const struct cred *id_resolver_cache;
53
54 struct key_type key_type_id_resolver = {
55         .name           = "id_resolver",
56         .instantiate    = user_instantiate,
57         .match          = user_match,
58         .revoke         = user_revoke,
59         .destroy        = user_destroy,
60         .describe       = user_describe,
61         .read           = user_read,
62 };
63
64 int nfs_idmap_init(void)
65 {
66         struct cred *cred;
67         struct key *keyring;
68         int ret = 0;
69
70         printk(KERN_NOTICE "Registering the %s key type\n", key_type_id_resolver.name);
71
72         cred = prepare_kernel_cred(NULL);
73         if (!cred)
74                 return -ENOMEM;
75
76         keyring = key_alloc(&key_type_keyring, ".id_resolver", 0, 0, cred,
77                              (KEY_POS_ALL & ~KEY_POS_SETATTR) |
78                              KEY_USR_VIEW | KEY_USR_READ,
79                              KEY_ALLOC_NOT_IN_QUOTA);
80         if (IS_ERR(keyring)) {
81                 ret = PTR_ERR(keyring);
82                 goto failed_put_cred;
83         }
84
85         ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL);
86         if (ret < 0)
87                 goto failed_put_key;
88
89         ret = register_key_type(&key_type_id_resolver);
90         if (ret < 0)
91                 goto failed_put_key;
92
93         cred->thread_keyring = keyring;
94         cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
95         id_resolver_cache = cred;
96         return 0;
97
98 failed_put_key:
99         key_put(keyring);
100 failed_put_cred:
101         put_cred(cred);
102         return ret;
103 }
104
105 void nfs_idmap_quit(void)
106 {
107         key_revoke(id_resolver_cache->thread_keyring);
108         unregister_key_type(&key_type_id_resolver);
109         put_cred(id_resolver_cache);
110 }
111
112 /*
113  * Assemble the description to pass to request_key()
114  * This function will allocate a new string and update dest to point
115  * at it.  The caller is responsible for freeing dest.
116  *
117  * On error 0 is returned.  Otherwise, the length of dest is returned.
118  */
119 static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
120                                 const char *type, size_t typelen, char **desc)
121 {
122         char *cp;
123         size_t desclen = typelen + namelen + 2;
124
125         *desc = kmalloc(desclen, GFP_KERNEL);
126         if (!desc)
127                 return -ENOMEM;
128
129         cp = *desc;
130         memcpy(cp, type, typelen);
131         cp += typelen;
132         *cp++ = ':';
133
134         memcpy(cp, name, namelen);
135         cp += namelen;
136         *cp = '\0';
137         return desclen;
138 }
139
140 static ssize_t nfs_idmap_request_key(const char *name, size_t namelen,
141                 const char *type, void *data, size_t data_size)
142 {
143         const struct cred *saved_cred;
144         struct key *rkey;
145         char *desc;
146         struct user_key_payload *payload;
147         ssize_t ret;
148
149         ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
150         if (ret <= 0)
151                 goto out;
152
153         saved_cred = override_creds(id_resolver_cache);
154         rkey = request_key(&key_type_id_resolver, desc, "");
155         revert_creds(saved_cred);
156         kfree(desc);
157         if (IS_ERR(rkey)) {
158                 ret = PTR_ERR(rkey);
159                 goto out;
160         }
161
162         rcu_read_lock();
163         rkey->perm |= KEY_USR_VIEW;
164
165         ret = key_validate(rkey);
166         if (ret < 0)
167                 goto out_up;
168
169         payload = rcu_dereference(rkey->payload.data);
170         if (IS_ERR_OR_NULL(payload)) {
171                 ret = PTR_ERR(payload);
172                 goto out_up;
173         }
174
175         ret = payload->datalen;
176         if (ret > 0 && ret <= data_size)
177                 memcpy(data, payload->data, ret);
178         else
179                 ret = -EINVAL;
180
181 out_up:
182         rcu_read_unlock();
183         key_put(rkey);
184 out:
185         return ret;
186 }
187
188
189 /* ID -> Name */
190 static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf, size_t buflen)
191 {
192         char id_str[NFS_UINT_MAXLEN];
193         int id_len;
194         ssize_t ret;
195
196         id_len = snprintf(id_str, sizeof(id_str), "%u", id);
197         ret = nfs_idmap_request_key(id_str, id_len, type, buf, buflen);
198         if (ret < 0)
199                 return -EINVAL;
200         return ret;
201 }
202
203 /* Name -> ID */
204 static int nfs_idmap_lookup_id(const char *name, size_t namelen,
205                                 const char *type, __u32 *id)
206 {
207         char id_str[NFS_UINT_MAXLEN];
208         long id_long;
209         ssize_t data_size;
210         int ret = 0;
211
212         data_size = nfs_idmap_request_key(name, namelen, type, id_str, NFS_UINT_MAXLEN);
213         if (data_size <= 0) {
214                 ret = -EINVAL;
215         } else {
216                 ret = strict_strtol(id_str, 10, &id_long);
217                 *id = (__u32)id_long;
218         }
219         return ret;
220 }
221
222 int nfs_map_name_to_uid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *uid)
223 {
224         return nfs_idmap_lookup_id(name, namelen, "uid", uid);
225 }
226
227 int nfs_map_group_to_gid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *gid)
228 {
229         return nfs_idmap_lookup_id(name, namelen, "gid", gid);
230 }
231
232 int nfs_map_uid_to_name(struct nfs_client *clp, __u32 uid, char *buf, size_t buflen)
233 {
234         return nfs_idmap_lookup_name(uid, "user", buf, buflen);
235 }
236 int nfs_map_gid_to_group(struct nfs_client *clp, __u32 gid, char *buf, size_t buflen)
237 {
238         return nfs_idmap_lookup_name(gid, "group", buf, buflen);
239 }
240
241 #else  /* CONFIG_NFS_USE_IDMAPPER not defined */
242
243 #include <linux/module.h>
244 #include <linux/mutex.h>
245 #include <linux/init.h>
246 #include <linux/types.h>
247 #include <linux/slab.h>
248 #include <linux/socket.h>
249 #include <linux/in.h>
250 #include <linux/sched.h>
251
252 #include <linux/sunrpc/clnt.h>
253 #include <linux/workqueue.h>
254 #include <linux/sunrpc/rpc_pipe_fs.h>
255
256 #include <linux/nfs_fs.h>
257
258 #include <linux/nfs_idmap.h>
259 #include "nfs4_fs.h"
260
261 #define IDMAP_HASH_SZ          128
262
263 /* Default cache timeout is 10 minutes */
264 unsigned int nfs_idmap_cache_timeout = 600 * HZ;
265
266 static int param_set_idmap_timeout(const char *val, struct kernel_param *kp)
267 {
268         char *endp;
269         int num = simple_strtol(val, &endp, 0);
270         int jif = num * HZ;
271         if (endp == val || *endp || num < 0 || jif < num)
272                 return -EINVAL;
273         *((int *)kp->arg) = jif;
274         return 0;
275 }
276
277 module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int,
278                  &nfs_idmap_cache_timeout, 0644);
279
280 struct idmap_hashent {
281         unsigned long           ih_expires;
282         __u32                   ih_id;
283         size_t                  ih_namelen;
284         char                    ih_name[IDMAP_NAMESZ];
285 };
286
287 struct idmap_hashtable {
288         __u8                    h_type;
289         struct idmap_hashent    h_entries[IDMAP_HASH_SZ];
290 };
291
292 struct idmap {
293         struct dentry           *idmap_dentry;
294         wait_queue_head_t       idmap_wq;
295         struct idmap_msg        idmap_im;
296         struct mutex            idmap_lock;     /* Serializes upcalls */
297         struct mutex            idmap_im_lock;  /* Protects the hashtable */
298         struct idmap_hashtable  idmap_user_hash;
299         struct idmap_hashtable  idmap_group_hash;
300 };
301
302 static ssize_t idmap_pipe_upcall(struct file *, struct rpc_pipe_msg *,
303                                  char __user *, size_t);
304 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
305                                    size_t);
306 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
307
308 static unsigned int fnvhash32(const void *, size_t);
309
310 static const struct rpc_pipe_ops idmap_upcall_ops = {
311         .upcall         = idmap_pipe_upcall,
312         .downcall       = idmap_pipe_downcall,
313         .destroy_msg    = idmap_pipe_destroy_msg,
314 };
315
316 int
317 nfs_idmap_new(struct nfs_client *clp)
318 {
319         struct idmap *idmap;
320         int error;
321
322         BUG_ON(clp->cl_idmap != NULL);
323
324         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
325         if (idmap == NULL)
326                 return -ENOMEM;
327
328         idmap->idmap_dentry = rpc_mkpipe(clp->cl_rpcclient->cl_path.dentry,
329                         "idmap", idmap, &idmap_upcall_ops, 0);
330         if (IS_ERR(idmap->idmap_dentry)) {
331                 error = PTR_ERR(idmap->idmap_dentry);
332                 kfree(idmap);
333                 return error;
334         }
335
336         mutex_init(&idmap->idmap_lock);
337         mutex_init(&idmap->idmap_im_lock);
338         init_waitqueue_head(&idmap->idmap_wq);
339         idmap->idmap_user_hash.h_type = IDMAP_TYPE_USER;
340         idmap->idmap_group_hash.h_type = IDMAP_TYPE_GROUP;
341
342         clp->cl_idmap = idmap;
343         return 0;
344 }
345
346 void
347 nfs_idmap_delete(struct nfs_client *clp)
348 {
349         struct idmap *idmap = clp->cl_idmap;
350
351         if (!idmap)
352                 return;
353         rpc_unlink(idmap->idmap_dentry);
354         clp->cl_idmap = NULL;
355         kfree(idmap);
356 }
357
358 /*
359  * Helper routines for manipulating the hashtable
360  */
361 static inline struct idmap_hashent *
362 idmap_name_hash(struct idmap_hashtable* h, const char *name, size_t len)
363 {
364         return &h->h_entries[fnvhash32(name, len) % IDMAP_HASH_SZ];
365 }
366
367 static struct idmap_hashent *
368 idmap_lookup_name(struct idmap_hashtable *h, const char *name, size_t len)
369 {
370         struct idmap_hashent *he = idmap_name_hash(h, name, len);
371
372         if (he->ih_namelen != len || memcmp(he->ih_name, name, len) != 0)
373                 return NULL;
374         if (time_after(jiffies, he->ih_expires))
375                 return NULL;
376         return he;
377 }
378
379 static inline struct idmap_hashent *
380 idmap_id_hash(struct idmap_hashtable* h, __u32 id)
381 {
382         return &h->h_entries[fnvhash32(&id, sizeof(id)) % IDMAP_HASH_SZ];
383 }
384
385 static struct idmap_hashent *
386 idmap_lookup_id(struct idmap_hashtable *h, __u32 id)
387 {
388         struct idmap_hashent *he = idmap_id_hash(h, id);
389         if (he->ih_id != id || he->ih_namelen == 0)
390                 return NULL;
391         if (time_after(jiffies, he->ih_expires))
392                 return NULL;
393         return he;
394 }
395
396 /*
397  * Routines for allocating new entries in the hashtable.
398  * For now, we just have 1 entry per bucket, so it's all
399  * pretty trivial.
400  */
401 static inline struct idmap_hashent *
402 idmap_alloc_name(struct idmap_hashtable *h, char *name, size_t len)
403 {
404         return idmap_name_hash(h, name, len);
405 }
406
407 static inline struct idmap_hashent *
408 idmap_alloc_id(struct idmap_hashtable *h, __u32 id)
409 {
410         return idmap_id_hash(h, id);
411 }
412
413 static void
414 idmap_update_entry(struct idmap_hashent *he, const char *name,
415                 size_t namelen, __u32 id)
416 {
417         he->ih_id = id;
418         memcpy(he->ih_name, name, namelen);
419         he->ih_name[namelen] = '\0';
420         he->ih_namelen = namelen;
421         he->ih_expires = jiffies + nfs_idmap_cache_timeout;
422 }
423
424 /*
425  * Name -> ID
426  */
427 static int
428 nfs_idmap_id(struct idmap *idmap, struct idmap_hashtable *h,
429                 const char *name, size_t namelen, __u32 *id)
430 {
431         struct rpc_pipe_msg msg;
432         struct idmap_msg *im;
433         struct idmap_hashent *he;
434         DECLARE_WAITQUEUE(wq, current);
435         int ret = -EIO;
436
437         im = &idmap->idmap_im;
438
439         /*
440          * String sanity checks
441          * Note that the userland daemon expects NUL terminated strings
442          */
443         for (;;) {
444                 if (namelen == 0)
445                         return -EINVAL;
446                 if (name[namelen-1] != '\0')
447                         break;
448                 namelen--;
449         }
450         if (namelen >= IDMAP_NAMESZ)
451                 return -EINVAL;
452
453         mutex_lock(&idmap->idmap_lock);
454         mutex_lock(&idmap->idmap_im_lock);
455
456         he = idmap_lookup_name(h, name, namelen);
457         if (he != NULL) {
458                 *id = he->ih_id;
459                 ret = 0;
460                 goto out;
461         }
462
463         memset(im, 0, sizeof(*im));
464         memcpy(im->im_name, name, namelen);
465
466         im->im_type = h->h_type;
467         im->im_conv = IDMAP_CONV_NAMETOID;
468
469         memset(&msg, 0, sizeof(msg));
470         msg.data = im;
471         msg.len = sizeof(*im);
472
473         add_wait_queue(&idmap->idmap_wq, &wq);
474         if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
475                 remove_wait_queue(&idmap->idmap_wq, &wq);
476                 goto out;
477         }
478
479         set_current_state(TASK_UNINTERRUPTIBLE);
480         mutex_unlock(&idmap->idmap_im_lock);
481         schedule();
482         __set_current_state(TASK_RUNNING);
483         remove_wait_queue(&idmap->idmap_wq, &wq);
484         mutex_lock(&idmap->idmap_im_lock);
485
486         if (im->im_status & IDMAP_STATUS_SUCCESS) {
487                 *id = im->im_id;
488                 ret = 0;
489         }
490
491  out:
492         memset(im, 0, sizeof(*im));
493         mutex_unlock(&idmap->idmap_im_lock);
494         mutex_unlock(&idmap->idmap_lock);
495         return ret;
496 }
497
498 /*
499  * ID -> Name
500  */
501 static int
502 nfs_idmap_name(struct idmap *idmap, struct idmap_hashtable *h,
503                 __u32 id, char *name)
504 {
505         struct rpc_pipe_msg msg;
506         struct idmap_msg *im;
507         struct idmap_hashent *he;
508         DECLARE_WAITQUEUE(wq, current);
509         int ret = -EIO;
510         unsigned int len;
511
512         im = &idmap->idmap_im;
513
514         mutex_lock(&idmap->idmap_lock);
515         mutex_lock(&idmap->idmap_im_lock);
516
517         he = idmap_lookup_id(h, id);
518         if (he) {
519                 memcpy(name, he->ih_name, he->ih_namelen);
520                 ret = he->ih_namelen;
521                 goto out;
522         }
523
524         memset(im, 0, sizeof(*im));
525         im->im_type = h->h_type;
526         im->im_conv = IDMAP_CONV_IDTONAME;
527         im->im_id = id;
528
529         memset(&msg, 0, sizeof(msg));
530         msg.data = im;
531         msg.len = sizeof(*im);
532
533         add_wait_queue(&idmap->idmap_wq, &wq);
534
535         if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
536                 remove_wait_queue(&idmap->idmap_wq, &wq);
537                 goto out;
538         }
539
540         set_current_state(TASK_UNINTERRUPTIBLE);
541         mutex_unlock(&idmap->idmap_im_lock);
542         schedule();
543         __set_current_state(TASK_RUNNING);
544         remove_wait_queue(&idmap->idmap_wq, &wq);
545         mutex_lock(&idmap->idmap_im_lock);
546
547         if (im->im_status & IDMAP_STATUS_SUCCESS) {
548                 if ((len = strnlen(im->im_name, IDMAP_NAMESZ)) == 0)
549                         goto out;
550                 memcpy(name, im->im_name, len);
551                 ret = len;
552         }
553
554  out:
555         memset(im, 0, sizeof(*im));
556         mutex_unlock(&idmap->idmap_im_lock);
557         mutex_unlock(&idmap->idmap_lock);
558         return ret;
559 }
560
561 /* RPC pipefs upcall/downcall routines */
562 static ssize_t
563 idmap_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
564                   char __user *dst, size_t buflen)
565 {
566         char *data = (char *)msg->data + msg->copied;
567         size_t mlen = min(msg->len, buflen);
568         unsigned long left;
569
570         left = copy_to_user(dst, data, mlen);
571         if (left == mlen) {
572                 msg->errno = -EFAULT;
573                 return -EFAULT;
574         }
575
576         mlen -= left;
577         msg->copied += mlen;
578         msg->errno = 0;
579         return mlen;
580 }
581
582 static ssize_t
583 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
584 {
585         struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
586         struct idmap *idmap = (struct idmap *)rpci->private;
587         struct idmap_msg im_in, *im = &idmap->idmap_im;
588         struct idmap_hashtable *h;
589         struct idmap_hashent *he = NULL;
590         size_t namelen_in;
591         int ret;
592
593         if (mlen != sizeof(im_in))
594                 return -ENOSPC;
595
596         if (copy_from_user(&im_in, src, mlen) != 0)
597                 return -EFAULT;
598
599         mutex_lock(&idmap->idmap_im_lock);
600
601         ret = mlen;
602         im->im_status = im_in.im_status;
603         /* If we got an error, terminate now, and wake up pending upcalls */
604         if (!(im_in.im_status & IDMAP_STATUS_SUCCESS)) {
605                 wake_up(&idmap->idmap_wq);
606                 goto out;
607         }
608
609         /* Sanity checking of strings */
610         ret = -EINVAL;
611         namelen_in = strnlen(im_in.im_name, IDMAP_NAMESZ);
612         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ)
613                 goto out;
614
615         switch (im_in.im_type) {
616                 case IDMAP_TYPE_USER:
617                         h = &idmap->idmap_user_hash;
618                         break;
619                 case IDMAP_TYPE_GROUP:
620                         h = &idmap->idmap_group_hash;
621                         break;
622                 default:
623                         goto out;
624         }
625
626         switch (im_in.im_conv) {
627         case IDMAP_CONV_IDTONAME:
628                 /* Did we match the current upcall? */
629                 if (im->im_conv == IDMAP_CONV_IDTONAME
630                                 && im->im_type == im_in.im_type
631                                 && im->im_id == im_in.im_id) {
632                         /* Yes: copy string, including the terminating '\0'  */
633                         memcpy(im->im_name, im_in.im_name, namelen_in);
634                         im->im_name[namelen_in] = '\0';
635                         wake_up(&idmap->idmap_wq);
636                 }
637                 he = idmap_alloc_id(h, im_in.im_id);
638                 break;
639         case IDMAP_CONV_NAMETOID:
640                 /* Did we match the current upcall? */
641                 if (im->im_conv == IDMAP_CONV_NAMETOID
642                                 && im->im_type == im_in.im_type
643                                 && strnlen(im->im_name, IDMAP_NAMESZ) == namelen_in
644                                 && memcmp(im->im_name, im_in.im_name, namelen_in) == 0) {
645                         im->im_id = im_in.im_id;
646                         wake_up(&idmap->idmap_wq);
647                 }
648                 he = idmap_alloc_name(h, im_in.im_name, namelen_in);
649                 break;
650         default:
651                 goto out;
652         }
653
654         /* If the entry is valid, also copy it to the cache */
655         if (he != NULL)
656                 idmap_update_entry(he, im_in.im_name, namelen_in, im_in.im_id);
657         ret = mlen;
658 out:
659         mutex_unlock(&idmap->idmap_im_lock);
660         return ret;
661 }
662
663 static void
664 idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
665 {
666         struct idmap_msg *im = msg->data;
667         struct idmap *idmap = container_of(im, struct idmap, idmap_im); 
668
669         if (msg->errno >= 0)
670                 return;
671         mutex_lock(&idmap->idmap_im_lock);
672         im->im_status = IDMAP_STATUS_LOOKUPFAIL;
673         wake_up(&idmap->idmap_wq);
674         mutex_unlock(&idmap->idmap_im_lock);
675 }
676
677 /* 
678  * Fowler/Noll/Vo hash
679  *    http://www.isthe.com/chongo/tech/comp/fnv/
680  */
681
682 #define FNV_P_32 ((unsigned int)0x01000193) /* 16777619 */
683 #define FNV_1_32 ((unsigned int)0x811c9dc5) /* 2166136261 */
684
685 static unsigned int fnvhash32(const void *buf, size_t buflen)
686 {
687         const unsigned char *p, *end = (const unsigned char *)buf + buflen;
688         unsigned int hash = FNV_1_32;
689
690         for (p = buf; p < end; p++) {
691                 hash *= FNV_P_32;
692                 hash ^= (unsigned int)*p;
693         }
694
695         return hash;
696 }
697
698 int nfs_map_name_to_uid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *uid)
699 {
700         struct idmap *idmap = clp->cl_idmap;
701
702         return nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
703 }
704
705 int nfs_map_group_to_gid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *uid)
706 {
707         struct idmap *idmap = clp->cl_idmap;
708
709         return nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, uid);
710 }
711
712 int nfs_map_uid_to_name(struct nfs_client *clp, __u32 uid, char *buf, size_t buflen)
713 {
714         struct idmap *idmap = clp->cl_idmap;
715
716         return nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
717 }
718 int nfs_map_gid_to_group(struct nfs_client *clp, __u32 uid, char *buf, size_t buflen)
719 {
720         struct idmap *idmap = clp->cl_idmap;
721
722         return nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
723 }
724
725 #endif /* CONFIG_NFS_USE_NEW_IDMAPPER */