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TOMOYO Linux Cross Reference
Linux/fs/nfsd/nfs4recover.c

Version: ~ [ linux-5.6-rc3 ] ~ [ linux-5.5.6 ] ~ [ linux-5.4.22 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.106 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.171 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.214 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.214 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.82 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2 *  Copyright (c) 2004 The Regents of the University of Michigan.
  3 *  Copyright (c) 2012 Jeff Layton <jlayton@redhat.com>
  4 *  All rights reserved.
  5 *
  6 *  Andy Adamson <andros@citi.umich.edu>
  7 *
  8 *  Redistribution and use in source and binary forms, with or without
  9 *  modification, are permitted provided that the following conditions
 10 *  are met:
 11 *
 12 *  1. Redistributions of source code must retain the above copyright
 13 *     notice, this list of conditions and the following disclaimer.
 14 *  2. Redistributions in binary form must reproduce the above copyright
 15 *     notice, this list of conditions and the following disclaimer in the
 16 *     documentation and/or other materials provided with the distribution.
 17 *  3. Neither the name of the University nor the names of its
 18 *     contributors may be used to endorse or promote products derived
 19 *     from this software without specific prior written permission.
 20 *
 21 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 22 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 23 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 24 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 25 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 26 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 27 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 28 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 29 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 30 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 31 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 32 *
 33 */
 34 
 35 #include <linux/file.h>
 36 #include <linux/slab.h>
 37 #include <linux/namei.h>
 38 #include <linux/crypto.h>
 39 #include <linux/sched.h>
 40 #include <linux/fs.h>
 41 #include <linux/module.h>
 42 #include <net/net_namespace.h>
 43 #include <linux/sunrpc/rpc_pipe_fs.h>
 44 #include <linux/sunrpc/clnt.h>
 45 #include <linux/nfsd/cld.h>
 46 
 47 #include "nfsd.h"
 48 #include "state.h"
 49 #include "vfs.h"
 50 #include "netns.h"
 51 
 52 #define NFSDDBG_FACILITY                NFSDDBG_PROC
 53 
 54 /* Declarations */
 55 struct nfsd4_client_tracking_ops {
 56         int (*init)(struct net *);
 57         void (*exit)(struct net *);
 58         void (*create)(struct nfs4_client *);
 59         void (*remove)(struct nfs4_client *);
 60         int (*check)(struct nfs4_client *);
 61         void (*grace_done)(struct nfsd_net *, time_t);
 62 };
 63 
 64 /* Globals */
 65 static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
 66 
 67 static int
 68 nfs4_save_creds(const struct cred **original_creds)
 69 {
 70         struct cred *new;
 71 
 72         new = prepare_creds();
 73         if (!new)
 74                 return -ENOMEM;
 75 
 76         new->fsuid = GLOBAL_ROOT_UID;
 77         new->fsgid = GLOBAL_ROOT_GID;
 78         *original_creds = override_creds(new);
 79         put_cred(new);
 80         return 0;
 81 }
 82 
 83 static void
 84 nfs4_reset_creds(const struct cred *original)
 85 {
 86         revert_creds(original);
 87 }
 88 
 89 static void
 90 md5_to_hex(char *out, char *md5)
 91 {
 92         int i;
 93 
 94         for (i=0; i<16; i++) {
 95                 unsigned char c = md5[i];
 96 
 97                 *out++ = '' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
 98                 *out++ = '' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
 99         }
100         *out = '\0';
101 }
102 
103 static int
104 nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
105 {
106         struct xdr_netobj cksum;
107         struct hash_desc desc;
108         struct scatterlist sg;
109         int status;
110 
111         dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
112                         clname->len, clname->data);
113         desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
114         desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
115         if (IS_ERR(desc.tfm)) {
116                 status = PTR_ERR(desc.tfm);
117                 goto out_no_tfm;
118         }
119 
120         cksum.len = crypto_hash_digestsize(desc.tfm);
121         cksum.data = kmalloc(cksum.len, GFP_KERNEL);
122         if (cksum.data == NULL) {
123                 status = -ENOMEM;
124                 goto out;
125         }
126 
127         sg_init_one(&sg, clname->data, clname->len);
128 
129         status = crypto_hash_digest(&desc, &sg, sg.length, cksum.data);
130         if (status)
131                 goto out;
132 
133         md5_to_hex(dname, cksum.data);
134 
135         status = 0;
136 out:
137         kfree(cksum.data);
138         crypto_free_hash(desc.tfm);
139 out_no_tfm:
140         return status;
141 }
142 
143 /*
144  * If we had an error generating the recdir name for the legacy tracker
145  * then warn the admin. If the error doesn't appear to be transient,
146  * then disable recovery tracking.
147  */
148 static void
149 legacy_recdir_name_error(struct nfs4_client *clp, int error)
150 {
151         printk(KERN_ERR "NFSD: unable to generate recoverydir "
152                         "name (%d).\n", error);
153 
154         /*
155          * if the algorithm just doesn't exist, then disable the recovery
156          * tracker altogether. The crypto libs will generally return this if
157          * FIPS is enabled as well.
158          */
159         if (error == -ENOENT) {
160                 printk(KERN_ERR "NFSD: disabling legacy clientid tracking. "
161                         "Reboot recovery will not function correctly!\n");
162                 nfsd4_client_tracking_exit(clp->net);
163         }
164 }
165 
166 static void
167 nfsd4_create_clid_dir(struct nfs4_client *clp)
168 {
169         const struct cred *original_cred;
170         char dname[HEXDIR_LEN];
171         struct dentry *dir, *dentry;
172         struct nfs4_client_reclaim *crp;
173         int status;
174         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
175 
176         dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
177 
178         if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
179                 return;
180         if (!nn->rec_file)
181                 return;
182 
183         status = nfs4_make_rec_clidname(dname, &clp->cl_name);
184         if (status)
185                 return legacy_recdir_name_error(clp, status);
186 
187         status = nfs4_save_creds(&original_cred);
188         if (status < 0)
189                 return;
190 
191         status = mnt_want_write_file(nn->rec_file);
192         if (status)
193                 return;
194 
195         dir = nn->rec_file->f_path.dentry;
196         /* lock the parent */
197         mutex_lock(&dir->d_inode->i_mutex);
198 
199         dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
200         if (IS_ERR(dentry)) {
201                 status = PTR_ERR(dentry);
202                 goto out_unlock;
203         }
204         if (dentry->d_inode)
205                 /*
206                  * In the 4.1 case, where we're called from
207                  * reclaim_complete(), records from the previous reboot
208                  * may still be left, so this is OK.
209                  *
210                  * In the 4.0 case, we should never get here; but we may
211                  * as well be forgiving and just succeed silently.
212                  */
213                 goto out_put;
214         status = vfs_mkdir(dir->d_inode, dentry, S_IRWXU);
215 out_put:
216         dput(dentry);
217 out_unlock:
218         mutex_unlock(&dir->d_inode->i_mutex);
219         if (status == 0) {
220                 if (nn->in_grace) {
221                         crp = nfs4_client_to_reclaim(dname, nn);
222                         if (crp)
223                                 crp->cr_clp = clp;
224                 }
225                 vfs_fsync(nn->rec_file, 0);
226         } else {
227                 printk(KERN_ERR "NFSD: failed to write recovery record"
228                                 " (err %d); please check that %s exists"
229                                 " and is writeable", status,
230                                 user_recovery_dirname);
231         }
232         mnt_drop_write_file(nn->rec_file);
233         nfs4_reset_creds(original_cred);
234 }
235 
236 typedef int (recdir_func)(struct dentry *, struct dentry *, struct nfsd_net *);
237 
238 struct name_list {
239         char name[HEXDIR_LEN];
240         struct list_head list;
241 };
242 
243 static int
244 nfsd4_build_namelist(void *arg, const char *name, int namlen,
245                 loff_t offset, u64 ino, unsigned int d_type)
246 {
247         struct list_head *names = arg;
248         struct name_list *entry;
249 
250         if (namlen != HEXDIR_LEN - 1)
251                 return 0;
252         entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
253         if (entry == NULL)
254                 return -ENOMEM;
255         memcpy(entry->name, name, HEXDIR_LEN - 1);
256         entry->name[HEXDIR_LEN - 1] = '\0';
257         list_add(&entry->list, names);
258         return 0;
259 }
260 
261 static int
262 nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
263 {
264         const struct cred *original_cred;
265         struct dentry *dir = nn->rec_file->f_path.dentry;
266         LIST_HEAD(names);
267         int status;
268 
269         status = nfs4_save_creds(&original_cred);
270         if (status < 0)
271                 return status;
272 
273         status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
274         if (status < 0) {
275                 nfs4_reset_creds(original_cred);
276                 return status;
277         }
278 
279         status = vfs_readdir(nn->rec_file, nfsd4_build_namelist, &names);
280         mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
281         while (!list_empty(&names)) {
282                 struct name_list *entry;
283                 entry = list_entry(names.next, struct name_list, list);
284                 if (!status) {
285                         struct dentry *dentry;
286                         dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
287                         if (IS_ERR(dentry)) {
288                                 status = PTR_ERR(dentry);
289                                 break;
290                         }
291                         status = f(dir, dentry, nn);
292                         dput(dentry);
293                 }
294                 list_del(&entry->list);
295                 kfree(entry);
296         }
297         mutex_unlock(&dir->d_inode->i_mutex);
298         nfs4_reset_creds(original_cred);
299         return status;
300 }
301 
302 static int
303 nfsd4_unlink_clid_dir(char *name, int namlen, struct nfsd_net *nn)
304 {
305         struct dentry *dir, *dentry;
306         int status;
307 
308         dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
309 
310         dir = nn->rec_file->f_path.dentry;
311         mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
312         dentry = lookup_one_len(name, dir, namlen);
313         if (IS_ERR(dentry)) {
314                 status = PTR_ERR(dentry);
315                 goto out_unlock;
316         }
317         status = -ENOENT;
318         if (!dentry->d_inode)
319                 goto out;
320         status = vfs_rmdir(dir->d_inode, dentry);
321 out:
322         dput(dentry);
323 out_unlock:
324         mutex_unlock(&dir->d_inode->i_mutex);
325         return status;
326 }
327 
328 static void
329 nfsd4_remove_clid_dir(struct nfs4_client *clp)
330 {
331         const struct cred *original_cred;
332         struct nfs4_client_reclaim *crp;
333         char dname[HEXDIR_LEN];
334         int status;
335         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
336 
337         if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
338                 return;
339 
340         status = nfs4_make_rec_clidname(dname, &clp->cl_name);
341         if (status)
342                 return legacy_recdir_name_error(clp, status);
343 
344         status = mnt_want_write_file(nn->rec_file);
345         if (status)
346                 goto out;
347         clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
348 
349         status = nfs4_save_creds(&original_cred);
350         if (status < 0)
351                 goto out_drop_write;
352 
353         status = nfsd4_unlink_clid_dir(dname, HEXDIR_LEN-1, nn);
354         nfs4_reset_creds(original_cred);
355         if (status == 0) {
356                 vfs_fsync(nn->rec_file, 0);
357                 if (nn->in_grace) {
358                         /* remove reclaim record */
359                         crp = nfsd4_find_reclaim_client(dname, nn);
360                         if (crp)
361                                 nfs4_remove_reclaim_record(crp, nn);
362                 }
363         }
364 out_drop_write:
365         mnt_drop_write_file(nn->rec_file);
366 out:
367         if (status)
368                 printk("NFSD: Failed to remove expired client state directory"
369                                 " %.*s\n", HEXDIR_LEN, dname);
370 }
371 
372 static int
373 purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
374 {
375         int status;
376 
377         if (nfs4_has_reclaimed_state(child->d_name.name, nn))
378                 return 0;
379 
380         status = vfs_rmdir(parent->d_inode, child);
381         if (status)
382                 printk("failed to remove client recovery directory %s\n",
383                                 child->d_name.name);
384         /* Keep trying, success or failure: */
385         return 0;
386 }
387 
388 static void
389 nfsd4_recdir_purge_old(struct nfsd_net *nn, time_t boot_time)
390 {
391         int status;
392 
393         nn->in_grace = false;
394         if (!nn->rec_file)
395                 return;
396         status = mnt_want_write_file(nn->rec_file);
397         if (status)
398                 goto out;
399         status = nfsd4_list_rec_dir(purge_old, nn);
400         if (status == 0)
401                 vfs_fsync(nn->rec_file, 0);
402         mnt_drop_write_file(nn->rec_file);
403 out:
404         nfs4_release_reclaim(nn);
405         if (status)
406                 printk("nfsd4: failed to purge old clients from recovery"
407                         " directory %s\n", nn->rec_file->f_path.dentry->d_name.name);
408 }
409 
410 static int
411 load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
412 {
413         if (child->d_name.len != HEXDIR_LEN - 1) {
414                 printk("nfsd4: illegal name %s in recovery directory\n",
415                                 child->d_name.name);
416                 /* Keep trying; maybe the others are OK: */
417                 return 0;
418         }
419         nfs4_client_to_reclaim(child->d_name.name, nn);
420         return 0;
421 }
422 
423 static int
424 nfsd4_recdir_load(struct net *net) {
425         int status;
426         struct nfsd_net *nn =  net_generic(net, nfsd_net_id);
427 
428         if (!nn->rec_file)
429                 return 0;
430 
431         status = nfsd4_list_rec_dir(load_recdir, nn);
432         if (status)
433                 printk("nfsd4: failed loading clients from recovery"
434                         " directory %s\n", nn->rec_file->f_path.dentry->d_name.name);
435         return status;
436 }
437 
438 /*
439  * Hold reference to the recovery directory.
440  */
441 
442 static int
443 nfsd4_init_recdir(struct net *net)
444 {
445         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
446         const struct cred *original_cred;
447         int status;
448 
449         printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
450                         user_recovery_dirname);
451 
452         BUG_ON(nn->rec_file);
453 
454         status = nfs4_save_creds(&original_cred);
455         if (status < 0) {
456                 printk("NFSD: Unable to change credentials to find recovery"
457                        " directory: error %d\n",
458                        status);
459                 return status;
460         }
461 
462         nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
463         if (IS_ERR(nn->rec_file)) {
464                 printk("NFSD: unable to find recovery directory %s\n",
465                                 user_recovery_dirname);
466                 status = PTR_ERR(nn->rec_file);
467                 nn->rec_file = NULL;
468         }
469 
470         nfs4_reset_creds(original_cred);
471         if (!status)
472                 nn->in_grace = true;
473         return status;
474 }
475 
476 
477 static int
478 nfs4_legacy_state_init(struct net *net)
479 {
480         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
481         int i;
482 
483         nn->reclaim_str_hashtbl = kmalloc(sizeof(struct list_head) *
484                                           CLIENT_HASH_SIZE, GFP_KERNEL);
485         if (!nn->reclaim_str_hashtbl)
486                 return -ENOMEM;
487 
488         for (i = 0; i < CLIENT_HASH_SIZE; i++)
489                 INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
490         nn->reclaim_str_hashtbl_size = 0;
491 
492         return 0;
493 }
494 
495 static void
496 nfs4_legacy_state_shutdown(struct net *net)
497 {
498         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
499 
500         kfree(nn->reclaim_str_hashtbl);
501 }
502 
503 static int
504 nfsd4_load_reboot_recovery_data(struct net *net)
505 {
506         int status;
507 
508         status = nfsd4_init_recdir(net);
509         if (!status)
510                 status = nfsd4_recdir_load(net);
511         if (status)
512                 printk(KERN_ERR "NFSD: Failure reading reboot recovery data\n");
513         return status;
514 }
515 
516 static int
517 nfsd4_legacy_tracking_init(struct net *net)
518 {
519         int status;
520 
521         /* XXX: The legacy code won't work in a container */
522         if (net != &init_net) {
523                 WARN(1, KERN_ERR "NFSD: attempt to initialize legacy client "
524                         "tracking in a container!\n");
525                 return -EINVAL;
526         }
527 
528         status = nfs4_legacy_state_init(net);
529         if (status)
530                 return status;
531 
532         status = nfsd4_load_reboot_recovery_data(net);
533         if (status)
534                 goto err;
535         return 0;
536 
537 err:
538         nfs4_legacy_state_shutdown(net);
539         return status;
540 }
541 
542 static void
543 nfsd4_shutdown_recdir(struct nfsd_net *nn)
544 {
545         if (!nn->rec_file)
546                 return;
547         fput(nn->rec_file);
548         nn->rec_file = NULL;
549 }
550 
551 static void
552 nfsd4_legacy_tracking_exit(struct net *net)
553 {
554         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
555 
556         nfs4_release_reclaim(nn);
557         nfsd4_shutdown_recdir(nn);
558         nfs4_legacy_state_shutdown(net);
559 }
560 
561 /*
562  * Change the NFSv4 recovery directory to recdir.
563  */
564 int
565 nfs4_reset_recoverydir(char *recdir)
566 {
567         int status;
568         struct path path;
569 
570         status = kern_path(recdir, LOOKUP_FOLLOW, &path);
571         if (status)
572                 return status;
573         status = -ENOTDIR;
574         if (S_ISDIR(path.dentry->d_inode->i_mode)) {
575                 strcpy(user_recovery_dirname, recdir);
576                 status = 0;
577         }
578         path_put(&path);
579         return status;
580 }
581 
582 char *
583 nfs4_recoverydir(void)
584 {
585         return user_recovery_dirname;
586 }
587 
588 static int
589 nfsd4_check_legacy_client(struct nfs4_client *clp)
590 {
591         int status;
592         char dname[HEXDIR_LEN];
593         struct nfs4_client_reclaim *crp;
594         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
595 
596         /* did we already find that this client is stable? */
597         if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
598                 return 0;
599 
600         status = nfs4_make_rec_clidname(dname, &clp->cl_name);
601         if (status) {
602                 legacy_recdir_name_error(clp, status);
603                 return status;
604         }
605 
606         /* look for it in the reclaim hashtable otherwise */
607         crp = nfsd4_find_reclaim_client(dname, nn);
608         if (crp) {
609                 set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
610                 crp->cr_clp = clp;
611                 return 0;
612         }
613 
614         return -ENOENT;
615 }
616 
617 static struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
618         .init           = nfsd4_legacy_tracking_init,
619         .exit           = nfsd4_legacy_tracking_exit,
620         .create         = nfsd4_create_clid_dir,
621         .remove         = nfsd4_remove_clid_dir,
622         .check          = nfsd4_check_legacy_client,
623         .grace_done     = nfsd4_recdir_purge_old,
624 };
625 
626 /* Globals */
627 #define NFSD_PIPE_DIR           "nfsd"
628 #define NFSD_CLD_PIPE           "cld"
629 
630 /* per-net-ns structure for holding cld upcall info */
631 struct cld_net {
632         struct rpc_pipe         *cn_pipe;
633         spinlock_t               cn_lock;
634         struct list_head         cn_list;
635         unsigned int             cn_xid;
636 };
637 
638 struct cld_upcall {
639         struct list_head         cu_list;
640         struct cld_net          *cu_net;
641         struct task_struct      *cu_task;
642         struct cld_msg           cu_msg;
643 };
644 
645 static int
646 __cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
647 {
648         int ret;
649         struct rpc_pipe_msg msg;
650 
651         memset(&msg, 0, sizeof(msg));
652         msg.data = cmsg;
653         msg.len = sizeof(*cmsg);
654 
655         /*
656          * Set task state before we queue the upcall. That prevents
657          * wake_up_process in the downcall from racing with schedule.
658          */
659         set_current_state(TASK_UNINTERRUPTIBLE);
660         ret = rpc_queue_upcall(pipe, &msg);
661         if (ret < 0) {
662                 set_current_state(TASK_RUNNING);
663                 goto out;
664         }
665 
666         schedule();
667         set_current_state(TASK_RUNNING);
668 
669         if (msg.errno < 0)
670                 ret = msg.errno;
671 out:
672         return ret;
673 }
674 
675 static int
676 cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
677 {
678         int ret;
679 
680         /*
681          * -EAGAIN occurs when pipe is closed and reopened while there are
682          *  upcalls queued.
683          */
684         do {
685                 ret = __cld_pipe_upcall(pipe, cmsg);
686         } while (ret == -EAGAIN);
687 
688         return ret;
689 }
690 
691 static ssize_t
692 cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
693 {
694         struct cld_upcall *tmp, *cup;
695         struct cld_msg __user *cmsg = (struct cld_msg __user *)src;
696         uint32_t xid;
697         struct nfsd_net *nn = net_generic(filp->f_dentry->d_sb->s_fs_info,
698                                                 nfsd_net_id);
699         struct cld_net *cn = nn->cld_net;
700 
701         if (mlen != sizeof(*cmsg)) {
702                 dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
703                         sizeof(*cmsg));
704                 return -EINVAL;
705         }
706 
707         /* copy just the xid so we can try to find that */
708         if (copy_from_user(&xid, &cmsg->cm_xid, sizeof(xid)) != 0) {
709                 dprintk("%s: error when copying xid from userspace", __func__);
710                 return -EFAULT;
711         }
712 
713         /* walk the list and find corresponding xid */
714         cup = NULL;
715         spin_lock(&cn->cn_lock);
716         list_for_each_entry(tmp, &cn->cn_list, cu_list) {
717                 if (get_unaligned(&tmp->cu_msg.cm_xid) == xid) {
718                         cup = tmp;
719                         list_del_init(&cup->cu_list);
720                         break;
721                 }
722         }
723         spin_unlock(&cn->cn_lock);
724 
725         /* couldn't find upcall? */
726         if (!cup) {
727                 dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
728                 return -EINVAL;
729         }
730 
731         if (copy_from_user(&cup->cu_msg, src, mlen) != 0)
732                 return -EFAULT;
733 
734         wake_up_process(cup->cu_task);
735         return mlen;
736 }
737 
738 static void
739 cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
740 {
741         struct cld_msg *cmsg = msg->data;
742         struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
743                                                  cu_msg);
744 
745         /* errno >= 0 means we got a downcall */
746         if (msg->errno >= 0)
747                 return;
748 
749         wake_up_process(cup->cu_task);
750 }
751 
752 static const struct rpc_pipe_ops cld_upcall_ops = {
753         .upcall         = rpc_pipe_generic_upcall,
754         .downcall       = cld_pipe_downcall,
755         .destroy_msg    = cld_pipe_destroy_msg,
756 };
757 
758 static struct dentry *
759 nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
760 {
761         struct dentry *dir, *dentry;
762 
763         dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
764         if (dir == NULL)
765                 return ERR_PTR(-ENOENT);
766         dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
767         dput(dir);
768         return dentry;
769 }
770 
771 static void
772 nfsd4_cld_unregister_sb(struct rpc_pipe *pipe)
773 {
774         if (pipe->dentry)
775                 rpc_unlink(pipe->dentry);
776 }
777 
778 static struct dentry *
779 nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
780 {
781         struct super_block *sb;
782         struct dentry *dentry;
783 
784         sb = rpc_get_sb_net(net);
785         if (!sb)
786                 return NULL;
787         dentry = nfsd4_cld_register_sb(sb, pipe);
788         rpc_put_sb_net(net);
789         return dentry;
790 }
791 
792 static void
793 nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
794 {
795         struct super_block *sb;
796 
797         sb = rpc_get_sb_net(net);
798         if (sb) {
799                 nfsd4_cld_unregister_sb(pipe);
800                 rpc_put_sb_net(net);
801         }
802 }
803 
804 /* Initialize rpc_pipefs pipe for communication with client tracking daemon */
805 static int
806 nfsd4_init_cld_pipe(struct net *net)
807 {
808         int ret;
809         struct dentry *dentry;
810         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
811         struct cld_net *cn;
812 
813         if (nn->cld_net)
814                 return 0;
815 
816         cn = kzalloc(sizeof(*cn), GFP_KERNEL);
817         if (!cn) {
818                 ret = -ENOMEM;
819                 goto err;
820         }
821 
822         cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
823         if (IS_ERR(cn->cn_pipe)) {
824                 ret = PTR_ERR(cn->cn_pipe);
825                 goto err;
826         }
827         spin_lock_init(&cn->cn_lock);
828         INIT_LIST_HEAD(&cn->cn_list);
829 
830         dentry = nfsd4_cld_register_net(net, cn->cn_pipe);
831         if (IS_ERR(dentry)) {
832                 ret = PTR_ERR(dentry);
833                 goto err_destroy_data;
834         }
835 
836         cn->cn_pipe->dentry = dentry;
837         nn->cld_net = cn;
838         return 0;
839 
840 err_destroy_data:
841         rpc_destroy_pipe_data(cn->cn_pipe);
842 err:
843         kfree(cn);
844         printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
845                         ret);
846         return ret;
847 }
848 
849 static void
850 nfsd4_remove_cld_pipe(struct net *net)
851 {
852         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
853         struct cld_net *cn = nn->cld_net;
854 
855         nfsd4_cld_unregister_net(net, cn->cn_pipe);
856         rpc_destroy_pipe_data(cn->cn_pipe);
857         kfree(nn->cld_net);
858         nn->cld_net = NULL;
859 }
860 
861 static struct cld_upcall *
862 alloc_cld_upcall(struct cld_net *cn)
863 {
864         struct cld_upcall *new, *tmp;
865 
866         new = kzalloc(sizeof(*new), GFP_KERNEL);
867         if (!new)
868                 return new;
869 
870         /* FIXME: hard cap on number in flight? */
871 restart_search:
872         spin_lock(&cn->cn_lock);
873         list_for_each_entry(tmp, &cn->cn_list, cu_list) {
874                 if (tmp->cu_msg.cm_xid == cn->cn_xid) {
875                         cn->cn_xid++;
876                         spin_unlock(&cn->cn_lock);
877                         goto restart_search;
878                 }
879         }
880         new->cu_task = current;
881         new->cu_msg.cm_vers = CLD_UPCALL_VERSION;
882         put_unaligned(cn->cn_xid++, &new->cu_msg.cm_xid);
883         new->cu_net = cn;
884         list_add(&new->cu_list, &cn->cn_list);
885         spin_unlock(&cn->cn_lock);
886 
887         dprintk("%s: allocated xid %u\n", __func__, new->cu_msg.cm_xid);
888 
889         return new;
890 }
891 
892 static void
893 free_cld_upcall(struct cld_upcall *victim)
894 {
895         struct cld_net *cn = victim->cu_net;
896 
897         spin_lock(&cn->cn_lock);
898         list_del(&victim->cu_list);
899         spin_unlock(&cn->cn_lock);
900         kfree(victim);
901 }
902 
903 /* Ask daemon to create a new record */
904 static void
905 nfsd4_cld_create(struct nfs4_client *clp)
906 {
907         int ret;
908         struct cld_upcall *cup;
909         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
910         struct cld_net *cn = nn->cld_net;
911 
912         /* Don't upcall if it's already stored */
913         if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
914                 return;
915 
916         cup = alloc_cld_upcall(cn);
917         if (!cup) {
918                 ret = -ENOMEM;
919                 goto out_err;
920         }
921 
922         cup->cu_msg.cm_cmd = Cld_Create;
923         cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
924         memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
925                         clp->cl_name.len);
926 
927         ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
928         if (!ret) {
929                 ret = cup->cu_msg.cm_status;
930                 set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
931         }
932 
933         free_cld_upcall(cup);
934 out_err:
935         if (ret)
936                 printk(KERN_ERR "NFSD: Unable to create client "
937                                 "record on stable storage: %d\n", ret);
938 }
939 
940 /* Ask daemon to create a new record */
941 static void
942 nfsd4_cld_remove(struct nfs4_client *clp)
943 {
944         int ret;
945         struct cld_upcall *cup;
946         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
947         struct cld_net *cn = nn->cld_net;
948 
949         /* Don't upcall if it's already removed */
950         if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
951                 return;
952 
953         cup = alloc_cld_upcall(cn);
954         if (!cup) {
955                 ret = -ENOMEM;
956                 goto out_err;
957         }
958 
959         cup->cu_msg.cm_cmd = Cld_Remove;
960         cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
961         memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
962                         clp->cl_name.len);
963 
964         ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
965         if (!ret) {
966                 ret = cup->cu_msg.cm_status;
967                 clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
968         }
969 
970         free_cld_upcall(cup);
971 out_err:
972         if (ret)
973                 printk(KERN_ERR "NFSD: Unable to remove client "
974                                 "record from stable storage: %d\n", ret);
975 }
976 
977 /* Check for presence of a record, and update its timestamp */
978 static int
979 nfsd4_cld_check(struct nfs4_client *clp)
980 {
981         int ret;
982         struct cld_upcall *cup;
983         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
984         struct cld_net *cn = nn->cld_net;
985 
986         /* Don't upcall if one was already stored during this grace pd */
987         if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
988                 return 0;
989 
990         cup = alloc_cld_upcall(cn);
991         if (!cup) {
992                 printk(KERN_ERR "NFSD: Unable to check client record on "
993                                 "stable storage: %d\n", -ENOMEM);
994                 return -ENOMEM;
995         }
996 
997         cup->cu_msg.cm_cmd = Cld_Check;
998         cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
999         memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1000                         clp->cl_name.len);
1001 
1002         ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
1003         if (!ret) {
1004                 ret = cup->cu_msg.cm_status;
1005                 set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1006         }
1007 
1008         free_cld_upcall(cup);
1009         return ret;
1010 }
1011 
1012 static void
1013 nfsd4_cld_grace_done(struct nfsd_net *nn, time_t boot_time)
1014 {
1015         int ret;
1016         struct cld_upcall *cup;
1017         struct cld_net *cn = nn->cld_net;
1018 
1019         cup = alloc_cld_upcall(cn);
1020         if (!cup) {
1021                 ret = -ENOMEM;
1022                 goto out_err;
1023         }
1024 
1025         cup->cu_msg.cm_cmd = Cld_GraceDone;
1026         cup->cu_msg.cm_u.cm_gracetime = (int64_t)boot_time;
1027         ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
1028         if (!ret)
1029                 ret = cup->cu_msg.cm_status;
1030 
1031         free_cld_upcall(cup);
1032 out_err:
1033         if (ret)
1034                 printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1035 }
1036 
1037 static struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
1038         .init           = nfsd4_init_cld_pipe,
1039         .exit           = nfsd4_remove_cld_pipe,
1040         .create         = nfsd4_cld_create,
1041         .remove         = nfsd4_cld_remove,
1042         .check          = nfsd4_cld_check,
1043         .grace_done     = nfsd4_cld_grace_done,
1044 };
1045 
1046 /* upcall via usermodehelper */
1047 static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
1048 module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
1049                         S_IRUGO|S_IWUSR);
1050 MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
1051 
1052 static bool cltrack_legacy_disable;
1053 module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
1054 MODULE_PARM_DESC(cltrack_legacy_disable,
1055                 "Disable legacy recoverydir conversion. Default: false");
1056 
1057 #define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
1058 #define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
1059 
1060 static char *
1061 nfsd4_cltrack_legacy_topdir(void)
1062 {
1063         int copied;
1064         size_t len;
1065         char *result;
1066 
1067         if (cltrack_legacy_disable)
1068                 return NULL;
1069 
1070         len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
1071                 strlen(nfs4_recoverydir()) + 1;
1072 
1073         result = kmalloc(len, GFP_KERNEL);
1074         if (!result)
1075                 return result;
1076 
1077         copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
1078                                 nfs4_recoverydir());
1079         if (copied >= len) {
1080                 /* just return nothing if output was truncated */
1081                 kfree(result);
1082                 return NULL;
1083         }
1084 
1085         return result;
1086 }
1087 
1088 static char *
1089 nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
1090 {
1091         int copied;
1092         size_t len;
1093         char *result;
1094 
1095         if (cltrack_legacy_disable)
1096                 return NULL;
1097 
1098         /* +1 is for '/' between "topdir" and "recdir" */
1099         len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
1100                 strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
1101 
1102         result = kmalloc(len, GFP_KERNEL);
1103         if (!result)
1104                 return result;
1105 
1106         copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
1107                                 nfs4_recoverydir());
1108         if (copied > (len - HEXDIR_LEN)) {
1109                 /* just return nothing if output will be truncated */
1110                 kfree(result);
1111                 return NULL;
1112         }
1113 
1114         copied = nfs4_make_rec_clidname(result + copied, name);
1115         if (copied) {
1116                 kfree(result);
1117                 return NULL;
1118         }
1119 
1120         return result;
1121 }
1122 
1123 static int
1124 nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *legacy)
1125 {
1126         char *envp[2];
1127         char *argv[4];
1128         int ret;
1129 
1130         if (unlikely(!cltrack_prog[0])) {
1131                 dprintk("%s: cltrack_prog is disabled\n", __func__);
1132                 return -EACCES;
1133         }
1134 
1135         dprintk("%s: cmd: %s\n", __func__, cmd);
1136         dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
1137         dprintk("%s: legacy: %s\n", __func__, legacy ? legacy : "(null)");
1138 
1139         envp[0] = legacy;
1140         envp[1] = NULL;
1141 
1142         argv[0] = (char *)cltrack_prog;
1143         argv[1] = cmd;
1144         argv[2] = arg;
1145         argv[3] = NULL;
1146 
1147         ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
1148         /*
1149          * Disable the upcall mechanism if we're getting an ENOENT or EACCES
1150          * error. The admin can re-enable it on the fly by using sysfs
1151          * once the problem has been fixed.
1152          */
1153         if (ret == -ENOENT || ret == -EACCES) {
1154                 dprintk("NFSD: %s was not found or isn't executable (%d). "
1155                         "Setting cltrack_prog to blank string!",
1156                         cltrack_prog, ret);
1157                 cltrack_prog[0] = '\0';
1158         }
1159         dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
1160 
1161         return ret;
1162 }
1163 
1164 static char *
1165 bin_to_hex_dup(const unsigned char *src, int srclen)
1166 {
1167         int i;
1168         char *buf, *hex;
1169 
1170         /* +1 for terminating NULL */
1171         buf = kmalloc((srclen * 2) + 1, GFP_KERNEL);
1172         if (!buf)
1173                 return buf;
1174 
1175         hex = buf;
1176         for (i = 0; i < srclen; i++) {
1177                 sprintf(hex, "%2.2x", *src++);
1178                 hex += 2;
1179         }
1180         return buf;
1181 }
1182 
1183 static int
1184 nfsd4_umh_cltrack_init(struct net __attribute__((unused)) *net)
1185 {
1186         /* XXX: The usermode helper s not working in container yet. */
1187         if (net != &init_net) {
1188                 WARN(1, KERN_ERR "NFSD: attempt to initialize umh client "
1189                         "tracking in a container!\n");
1190                 return -EINVAL;
1191         }
1192         return nfsd4_umh_cltrack_upcall("init", NULL, NULL);
1193 }
1194 
1195 static void
1196 nfsd4_umh_cltrack_create(struct nfs4_client *clp)
1197 {
1198         char *hexid;
1199 
1200         hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1201         if (!hexid) {
1202                 dprintk("%s: can't allocate memory for upcall!\n", __func__);
1203                 return;
1204         }
1205         nfsd4_umh_cltrack_upcall("create", hexid, NULL);
1206         kfree(hexid);
1207 }
1208 
1209 static void
1210 nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
1211 {
1212         char *hexid;
1213 
1214         hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1215         if (!hexid) {
1216                 dprintk("%s: can't allocate memory for upcall!\n", __func__);
1217                 return;
1218         }
1219         nfsd4_umh_cltrack_upcall("remove", hexid, NULL);
1220         kfree(hexid);
1221 }
1222 
1223 static int
1224 nfsd4_umh_cltrack_check(struct nfs4_client *clp)
1225 {
1226         int ret;
1227         char *hexid, *legacy;
1228 
1229         hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1230         if (!hexid) {
1231                 dprintk("%s: can't allocate memory for upcall!\n", __func__);
1232                 return -ENOMEM;
1233         }
1234         legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
1235         ret = nfsd4_umh_cltrack_upcall("check", hexid, legacy);
1236         kfree(legacy);
1237         kfree(hexid);
1238         return ret;
1239 }
1240 
1241 static void
1242 nfsd4_umh_cltrack_grace_done(struct nfsd_net __attribute__((unused)) *nn,
1243                                 time_t boot_time)
1244 {
1245         char *legacy;
1246         char timestr[22]; /* FIXME: better way to determine max size? */
1247 
1248         sprintf(timestr, "%ld", boot_time);
1249         legacy = nfsd4_cltrack_legacy_topdir();
1250         nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy);
1251         kfree(legacy);
1252 }
1253 
1254 static struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
1255         .init           = nfsd4_umh_cltrack_init,
1256         .exit           = NULL,
1257         .create         = nfsd4_umh_cltrack_create,
1258         .remove         = nfsd4_umh_cltrack_remove,
1259         .check          = nfsd4_umh_cltrack_check,
1260         .grace_done     = nfsd4_umh_cltrack_grace_done,
1261 };
1262 
1263 int
1264 nfsd4_client_tracking_init(struct net *net)
1265 {
1266         int status;
1267         struct path path;
1268         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1269 
1270         /* just run the init if it the method is already decided */
1271         if (nn->client_tracking_ops)
1272                 goto do_init;
1273 
1274         /*
1275          * First, try a UMH upcall. It should succeed or fail quickly, so
1276          * there's little harm in trying that first.
1277          */
1278         nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
1279         status = nn->client_tracking_ops->init(net);
1280         if (!status)
1281                 return status;
1282 
1283         /*
1284          * See if the recoverydir exists and is a directory. If it is,
1285          * then use the legacy ops.
1286          */
1287         nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
1288         status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
1289         if (!status) {
1290                 status = S_ISDIR(path.dentry->d_inode->i_mode);
1291                 path_put(&path);
1292                 if (status)
1293                         goto do_init;
1294         }
1295 
1296         /* Finally, try to use nfsdcld */
1297         nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
1298         printk(KERN_WARNING "NFSD: the nfsdcld client tracking upcall will be "
1299                         "removed in 3.10. Please transition to using "
1300                         "nfsdcltrack.\n");
1301 do_init:
1302         status = nn->client_tracking_ops->init(net);
1303         if (status) {
1304                 printk(KERN_WARNING "NFSD: Unable to initialize client "
1305                                     "recovery tracking! (%d)\n", status);
1306                 nn->client_tracking_ops = NULL;
1307         }
1308         return status;
1309 }
1310 
1311 void
1312 nfsd4_client_tracking_exit(struct net *net)
1313 {
1314         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1315 
1316         if (nn->client_tracking_ops) {
1317                 if (nn->client_tracking_ops->exit)
1318                         nn->client_tracking_ops->exit(net);
1319                 nn->client_tracking_ops = NULL;
1320         }
1321 }
1322 
1323 void
1324 nfsd4_client_record_create(struct nfs4_client *clp)
1325 {
1326         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1327 
1328         if (nn->client_tracking_ops)
1329                 nn->client_tracking_ops->create(clp);
1330 }
1331 
1332 void
1333 nfsd4_client_record_remove(struct nfs4_client *clp)
1334 {
1335         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1336 
1337         if (nn->client_tracking_ops)
1338                 nn->client_tracking_ops->remove(clp);
1339 }
1340 
1341 int
1342 nfsd4_client_record_check(struct nfs4_client *clp)
1343 {
1344         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1345 
1346         if (nn->client_tracking_ops)
1347                 return nn->client_tracking_ops->check(clp);
1348 
1349         return -EOPNOTSUPP;
1350 }
1351 
1352 void
1353 nfsd4_record_grace_done(struct nfsd_net *nn, time_t boot_time)
1354 {
1355         if (nn->client_tracking_ops)
1356                 nn->client_tracking_ops->grace_done(nn, boot_time);
1357 }
1358 
1359 static int
1360 rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
1361 {
1362         struct super_block *sb = ptr;
1363         struct net *net = sb->s_fs_info;
1364         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1365         struct cld_net *cn = nn->cld_net;
1366         struct dentry *dentry;
1367         int ret = 0;
1368 
1369         if (!try_module_get(THIS_MODULE))
1370                 return 0;
1371 
1372         if (!cn) {
1373                 module_put(THIS_MODULE);
1374                 return 0;
1375         }
1376 
1377         switch (event) {
1378         case RPC_PIPEFS_MOUNT:
1379                 dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
1380                 if (IS_ERR(dentry)) {
1381                         ret = PTR_ERR(dentry);
1382                         break;
1383                 }
1384                 cn->cn_pipe->dentry = dentry;
1385                 break;
1386         case RPC_PIPEFS_UMOUNT:
1387                 if (cn->cn_pipe->dentry)
1388                         nfsd4_cld_unregister_sb(cn->cn_pipe);
1389                 break;
1390         default:
1391                 ret = -ENOTSUPP;
1392                 break;
1393         }
1394         module_put(THIS_MODULE);
1395         return ret;
1396 }
1397 
1398 static struct notifier_block nfsd4_cld_block = {
1399         .notifier_call = rpc_pipefs_event,
1400 };
1401 
1402 int
1403 register_cld_notifier(void)
1404 {
1405         return rpc_pipefs_notifier_register(&nfsd4_cld_block);
1406 }
1407 
1408 void
1409 unregister_cld_notifier(void)
1410 {
1411         rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
1412 }
1413 

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