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

Version: ~ [ linux-5.1-rc2 ] ~ [ linux-5.0.3 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.30 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.107 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.164 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.176 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.136 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.63 ] ~ [ 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-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ 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 <crypto/hash.h>
 36 #include <linux/file.h>
 37 #include <linux/slab.h>
 38 #include <linux/namei.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 *);
 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 crypto_shash *tfm;
108         int status;
109 
110         dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
111                         clname->len, clname->data);
112         tfm = crypto_alloc_shash("md5", 0, 0);
113         if (IS_ERR(tfm)) {
114                 status = PTR_ERR(tfm);
115                 goto out_no_tfm;
116         }
117 
118         cksum.len = crypto_shash_digestsize(tfm);
119         cksum.data = kmalloc(cksum.len, GFP_KERNEL);
120         if (cksum.data == NULL) {
121                 status = -ENOMEM;
122                 goto out;
123         }
124 
125         {
126                 SHASH_DESC_ON_STACK(desc, tfm);
127 
128                 desc->tfm = tfm;
129                 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
130 
131                 status = crypto_shash_digest(desc, clname->data, clname->len,
132                                              cksum.data);
133                 shash_desc_zero(desc);
134         }
135 
136         if (status)
137                 goto out;
138 
139         md5_to_hex(dname, cksum.data);
140 
141         status = 0;
142 out:
143         kfree(cksum.data);
144         crypto_free_shash(tfm);
145 out_no_tfm:
146         return status;
147 }
148 
149 /*
150  * If we had an error generating the recdir name for the legacy tracker
151  * then warn the admin. If the error doesn't appear to be transient,
152  * then disable recovery tracking.
153  */
154 static void
155 legacy_recdir_name_error(struct nfs4_client *clp, int error)
156 {
157         printk(KERN_ERR "NFSD: unable to generate recoverydir "
158                         "name (%d).\n", error);
159 
160         /*
161          * if the algorithm just doesn't exist, then disable the recovery
162          * tracker altogether. The crypto libs will generally return this if
163          * FIPS is enabled as well.
164          */
165         if (error == -ENOENT) {
166                 printk(KERN_ERR "NFSD: disabling legacy clientid tracking. "
167                         "Reboot recovery will not function correctly!\n");
168                 nfsd4_client_tracking_exit(clp->net);
169         }
170 }
171 
172 static void
173 nfsd4_create_clid_dir(struct nfs4_client *clp)
174 {
175         const struct cred *original_cred;
176         char dname[HEXDIR_LEN];
177         struct dentry *dir, *dentry;
178         struct nfs4_client_reclaim *crp;
179         int status;
180         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
181 
182         if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
183                 return;
184         if (!nn->rec_file)
185                 return;
186 
187         status = nfs4_make_rec_clidname(dname, &clp->cl_name);
188         if (status)
189                 return legacy_recdir_name_error(clp, status);
190 
191         status = nfs4_save_creds(&original_cred);
192         if (status < 0)
193                 return;
194 
195         status = mnt_want_write_file(nn->rec_file);
196         if (status)
197                 goto out_creds;
198 
199         dir = nn->rec_file->f_path.dentry;
200         /* lock the parent */
201         inode_lock(d_inode(dir));
202 
203         dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
204         if (IS_ERR(dentry)) {
205                 status = PTR_ERR(dentry);
206                 goto out_unlock;
207         }
208         if (d_really_is_positive(dentry))
209                 /*
210                  * In the 4.1 case, where we're called from
211                  * reclaim_complete(), records from the previous reboot
212                  * may still be left, so this is OK.
213                  *
214                  * In the 4.0 case, we should never get here; but we may
215                  * as well be forgiving and just succeed silently.
216                  */
217                 goto out_put;
218         status = vfs_mkdir(d_inode(dir), dentry, S_IRWXU);
219 out_put:
220         dput(dentry);
221 out_unlock:
222         inode_unlock(d_inode(dir));
223         if (status == 0) {
224                 if (nn->in_grace) {
225                         crp = nfs4_client_to_reclaim(dname, nn);
226                         if (crp)
227                                 crp->cr_clp = clp;
228                 }
229                 vfs_fsync(nn->rec_file, 0);
230         } else {
231                 printk(KERN_ERR "NFSD: failed to write recovery record"
232                                 " (err %d); please check that %s exists"
233                                 " and is writeable", status,
234                                 user_recovery_dirname);
235         }
236         mnt_drop_write_file(nn->rec_file);
237 out_creds:
238         nfs4_reset_creds(original_cred);
239 }
240 
241 typedef int (recdir_func)(struct dentry *, struct dentry *, struct nfsd_net *);
242 
243 struct name_list {
244         char name[HEXDIR_LEN];
245         struct list_head list;
246 };
247 
248 struct nfs4_dir_ctx {
249         struct dir_context ctx;
250         struct list_head names;
251 };
252 
253 static int
254 nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
255                 loff_t offset, u64 ino, unsigned int d_type)
256 {
257         struct nfs4_dir_ctx *ctx =
258                 container_of(__ctx, struct nfs4_dir_ctx, ctx);
259         struct name_list *entry;
260 
261         if (namlen != HEXDIR_LEN - 1)
262                 return 0;
263         entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
264         if (entry == NULL)
265                 return -ENOMEM;
266         memcpy(entry->name, name, HEXDIR_LEN - 1);
267         entry->name[HEXDIR_LEN - 1] = '\0';
268         list_add(&entry->list, &ctx->names);
269         return 0;
270 }
271 
272 static int
273 nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
274 {
275         const struct cred *original_cred;
276         struct dentry *dir = nn->rec_file->f_path.dentry;
277         struct nfs4_dir_ctx ctx = {
278                 .ctx.actor = nfsd4_build_namelist,
279                 .names = LIST_HEAD_INIT(ctx.names)
280         };
281         struct name_list *entry, *tmp;
282         int status;
283 
284         status = nfs4_save_creds(&original_cred);
285         if (status < 0)
286                 return status;
287 
288         status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
289         if (status < 0) {
290                 nfs4_reset_creds(original_cred);
291                 return status;
292         }
293 
294         status = iterate_dir(nn->rec_file, &ctx.ctx);
295         inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
296 
297         list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
298                 if (!status) {
299                         struct dentry *dentry;
300                         dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
301                         if (IS_ERR(dentry)) {
302                                 status = PTR_ERR(dentry);
303                                 break;
304                         }
305                         status = f(dir, dentry, nn);
306                         dput(dentry);
307                 }
308                 list_del(&entry->list);
309                 kfree(entry);
310         }
311         inode_unlock(d_inode(dir));
312         nfs4_reset_creds(original_cred);
313 
314         list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
315                 dprintk("NFSD: %s. Left entry %s\n", __func__, entry->name);
316                 list_del(&entry->list);
317                 kfree(entry);
318         }
319         return status;
320 }
321 
322 static int
323 nfsd4_unlink_clid_dir(char *name, int namlen, struct nfsd_net *nn)
324 {
325         struct dentry *dir, *dentry;
326         int status;
327 
328         dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
329 
330         dir = nn->rec_file->f_path.dentry;
331         inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
332         dentry = lookup_one_len(name, dir, namlen);
333         if (IS_ERR(dentry)) {
334                 status = PTR_ERR(dentry);
335                 goto out_unlock;
336         }
337         status = -ENOENT;
338         if (d_really_is_negative(dentry))
339                 goto out;
340         status = vfs_rmdir(d_inode(dir), dentry);
341 out:
342         dput(dentry);
343 out_unlock:
344         inode_unlock(d_inode(dir));
345         return status;
346 }
347 
348 static void
349 nfsd4_remove_clid_dir(struct nfs4_client *clp)
350 {
351         const struct cred *original_cred;
352         struct nfs4_client_reclaim *crp;
353         char dname[HEXDIR_LEN];
354         int status;
355         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
356 
357         if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
358                 return;
359 
360         status = nfs4_make_rec_clidname(dname, &clp->cl_name);
361         if (status)
362                 return legacy_recdir_name_error(clp, status);
363 
364         status = mnt_want_write_file(nn->rec_file);
365         if (status)
366                 goto out;
367         clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
368 
369         status = nfs4_save_creds(&original_cred);
370         if (status < 0)
371                 goto out_drop_write;
372 
373         status = nfsd4_unlink_clid_dir(dname, HEXDIR_LEN-1, nn);
374         nfs4_reset_creds(original_cred);
375         if (status == 0) {
376                 vfs_fsync(nn->rec_file, 0);
377                 if (nn->in_grace) {
378                         /* remove reclaim record */
379                         crp = nfsd4_find_reclaim_client(dname, nn);
380                         if (crp)
381                                 nfs4_remove_reclaim_record(crp, nn);
382                 }
383         }
384 out_drop_write:
385         mnt_drop_write_file(nn->rec_file);
386 out:
387         if (status)
388                 printk("NFSD: Failed to remove expired client state directory"
389                                 " %.*s\n", HEXDIR_LEN, dname);
390 }
391 
392 static int
393 purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
394 {
395         int status;
396 
397         if (nfs4_has_reclaimed_state(child->d_name.name, nn))
398                 return 0;
399 
400         status = vfs_rmdir(d_inode(parent), child);
401         if (status)
402                 printk("failed to remove client recovery directory %pd\n",
403                                 child);
404         /* Keep trying, success or failure: */
405         return 0;
406 }
407 
408 static void
409 nfsd4_recdir_purge_old(struct nfsd_net *nn)
410 {
411         int status;
412 
413         nn->in_grace = false;
414         if (!nn->rec_file)
415                 return;
416         status = mnt_want_write_file(nn->rec_file);
417         if (status)
418                 goto out;
419         status = nfsd4_list_rec_dir(purge_old, nn);
420         if (status == 0)
421                 vfs_fsync(nn->rec_file, 0);
422         mnt_drop_write_file(nn->rec_file);
423 out:
424         nfs4_release_reclaim(nn);
425         if (status)
426                 printk("nfsd4: failed to purge old clients from recovery"
427                         " directory %pD\n", nn->rec_file);
428 }
429 
430 static int
431 load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
432 {
433         if (child->d_name.len != HEXDIR_LEN - 1) {
434                 printk("nfsd4: illegal name %pd in recovery directory\n",
435                                 child);
436                 /* Keep trying; maybe the others are OK: */
437                 return 0;
438         }
439         nfs4_client_to_reclaim(child->d_name.name, nn);
440         return 0;
441 }
442 
443 static int
444 nfsd4_recdir_load(struct net *net) {
445         int status;
446         struct nfsd_net *nn =  net_generic(net, nfsd_net_id);
447 
448         if (!nn->rec_file)
449                 return 0;
450 
451         status = nfsd4_list_rec_dir(load_recdir, nn);
452         if (status)
453                 printk("nfsd4: failed loading clients from recovery"
454                         " directory %pD\n", nn->rec_file);
455         return status;
456 }
457 
458 /*
459  * Hold reference to the recovery directory.
460  */
461 
462 static int
463 nfsd4_init_recdir(struct net *net)
464 {
465         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
466         const struct cred *original_cred;
467         int status;
468 
469         printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
470                         user_recovery_dirname);
471 
472         BUG_ON(nn->rec_file);
473 
474         status = nfs4_save_creds(&original_cred);
475         if (status < 0) {
476                 printk("NFSD: Unable to change credentials to find recovery"
477                        " directory: error %d\n",
478                        status);
479                 return status;
480         }
481 
482         nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
483         if (IS_ERR(nn->rec_file)) {
484                 printk("NFSD: unable to find recovery directory %s\n",
485                                 user_recovery_dirname);
486                 status = PTR_ERR(nn->rec_file);
487                 nn->rec_file = NULL;
488         }
489 
490         nfs4_reset_creds(original_cred);
491         if (!status)
492                 nn->in_grace = true;
493         return status;
494 }
495 
496 static void
497 nfsd4_shutdown_recdir(struct net *net)
498 {
499         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
500 
501         if (!nn->rec_file)
502                 return;
503         fput(nn->rec_file);
504         nn->rec_file = NULL;
505 }
506 
507 static int
508 nfs4_legacy_state_init(struct net *net)
509 {
510         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
511         int i;
512 
513         nn->reclaim_str_hashtbl = kmalloc(sizeof(struct list_head) *
514                                           CLIENT_HASH_SIZE, GFP_KERNEL);
515         if (!nn->reclaim_str_hashtbl)
516                 return -ENOMEM;
517 
518         for (i = 0; i < CLIENT_HASH_SIZE; i++)
519                 INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
520         nn->reclaim_str_hashtbl_size = 0;
521 
522         return 0;
523 }
524 
525 static void
526 nfs4_legacy_state_shutdown(struct net *net)
527 {
528         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
529 
530         kfree(nn->reclaim_str_hashtbl);
531 }
532 
533 static int
534 nfsd4_load_reboot_recovery_data(struct net *net)
535 {
536         int status;
537 
538         status = nfsd4_init_recdir(net);
539         if (status)
540                 return status;
541 
542         status = nfsd4_recdir_load(net);
543         if (status)
544                 nfsd4_shutdown_recdir(net);
545 
546         return status;
547 }
548 
549 static int
550 nfsd4_legacy_tracking_init(struct net *net)
551 {
552         int status;
553 
554         /* XXX: The legacy code won't work in a container */
555         if (net != &init_net) {
556                 pr_warn("NFSD: attempt to initialize legacy client tracking in a container ignored.\n");
557                 return -EINVAL;
558         }
559 
560         status = nfs4_legacy_state_init(net);
561         if (status)
562                 return status;
563 
564         status = nfsd4_load_reboot_recovery_data(net);
565         if (status)
566                 goto err;
567         return 0;
568 
569 err:
570         nfs4_legacy_state_shutdown(net);
571         return status;
572 }
573 
574 static void
575 nfsd4_legacy_tracking_exit(struct net *net)
576 {
577         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
578 
579         nfs4_release_reclaim(nn);
580         nfsd4_shutdown_recdir(net);
581         nfs4_legacy_state_shutdown(net);
582 }
583 
584 /*
585  * Change the NFSv4 recovery directory to recdir.
586  */
587 int
588 nfs4_reset_recoverydir(char *recdir)
589 {
590         int status;
591         struct path path;
592 
593         status = kern_path(recdir, LOOKUP_FOLLOW, &path);
594         if (status)
595                 return status;
596         status = -ENOTDIR;
597         if (d_is_dir(path.dentry)) {
598                 strcpy(user_recovery_dirname, recdir);
599                 status = 0;
600         }
601         path_put(&path);
602         return status;
603 }
604 
605 char *
606 nfs4_recoverydir(void)
607 {
608         return user_recovery_dirname;
609 }
610 
611 static int
612 nfsd4_check_legacy_client(struct nfs4_client *clp)
613 {
614         int status;
615         char dname[HEXDIR_LEN];
616         struct nfs4_client_reclaim *crp;
617         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
618 
619         /* did we already find that this client is stable? */
620         if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
621                 return 0;
622 
623         status = nfs4_make_rec_clidname(dname, &clp->cl_name);
624         if (status) {
625                 legacy_recdir_name_error(clp, status);
626                 return status;
627         }
628 
629         /* look for it in the reclaim hashtable otherwise */
630         crp = nfsd4_find_reclaim_client(dname, nn);
631         if (crp) {
632                 set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
633                 crp->cr_clp = clp;
634                 return 0;
635         }
636 
637         return -ENOENT;
638 }
639 
640 static const struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
641         .init           = nfsd4_legacy_tracking_init,
642         .exit           = nfsd4_legacy_tracking_exit,
643         .create         = nfsd4_create_clid_dir,
644         .remove         = nfsd4_remove_clid_dir,
645         .check          = nfsd4_check_legacy_client,
646         .grace_done     = nfsd4_recdir_purge_old,
647 };
648 
649 /* Globals */
650 #define NFSD_PIPE_DIR           "nfsd"
651 #define NFSD_CLD_PIPE           "cld"
652 
653 /* per-net-ns structure for holding cld upcall info */
654 struct cld_net {
655         struct rpc_pipe         *cn_pipe;
656         spinlock_t               cn_lock;
657         struct list_head         cn_list;
658         unsigned int             cn_xid;
659 };
660 
661 struct cld_upcall {
662         struct list_head         cu_list;
663         struct cld_net          *cu_net;
664         struct task_struct      *cu_task;
665         struct cld_msg           cu_msg;
666 };
667 
668 static int
669 __cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
670 {
671         int ret;
672         struct rpc_pipe_msg msg;
673 
674         memset(&msg, 0, sizeof(msg));
675         msg.data = cmsg;
676         msg.len = sizeof(*cmsg);
677 
678         /*
679          * Set task state before we queue the upcall. That prevents
680          * wake_up_process in the downcall from racing with schedule.
681          */
682         set_current_state(TASK_UNINTERRUPTIBLE);
683         ret = rpc_queue_upcall(pipe, &msg);
684         if (ret < 0) {
685                 set_current_state(TASK_RUNNING);
686                 goto out;
687         }
688 
689         schedule();
690 
691         if (msg.errno < 0)
692                 ret = msg.errno;
693 out:
694         return ret;
695 }
696 
697 static int
698 cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
699 {
700         int ret;
701 
702         /*
703          * -EAGAIN occurs when pipe is closed and reopened while there are
704          *  upcalls queued.
705          */
706         do {
707                 ret = __cld_pipe_upcall(pipe, cmsg);
708         } while (ret == -EAGAIN);
709 
710         return ret;
711 }
712 
713 static ssize_t
714 cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
715 {
716         struct cld_upcall *tmp, *cup;
717         struct cld_msg __user *cmsg = (struct cld_msg __user *)src;
718         uint32_t xid;
719         struct nfsd_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
720                                                 nfsd_net_id);
721         struct cld_net *cn = nn->cld_net;
722 
723         if (mlen != sizeof(*cmsg)) {
724                 dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
725                         sizeof(*cmsg));
726                 return -EINVAL;
727         }
728 
729         /* copy just the xid so we can try to find that */
730         if (copy_from_user(&xid, &cmsg->cm_xid, sizeof(xid)) != 0) {
731                 dprintk("%s: error when copying xid from userspace", __func__);
732                 return -EFAULT;
733         }
734 
735         /* walk the list and find corresponding xid */
736         cup = NULL;
737         spin_lock(&cn->cn_lock);
738         list_for_each_entry(tmp, &cn->cn_list, cu_list) {
739                 if (get_unaligned(&tmp->cu_msg.cm_xid) == xid) {
740                         cup = tmp;
741                         list_del_init(&cup->cu_list);
742                         break;
743                 }
744         }
745         spin_unlock(&cn->cn_lock);
746 
747         /* couldn't find upcall? */
748         if (!cup) {
749                 dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
750                 return -EINVAL;
751         }
752 
753         if (copy_from_user(&cup->cu_msg, src, mlen) != 0)
754                 return -EFAULT;
755 
756         wake_up_process(cup->cu_task);
757         return mlen;
758 }
759 
760 static void
761 cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
762 {
763         struct cld_msg *cmsg = msg->data;
764         struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
765                                                  cu_msg);
766 
767         /* errno >= 0 means we got a downcall */
768         if (msg->errno >= 0)
769                 return;
770 
771         wake_up_process(cup->cu_task);
772 }
773 
774 static const struct rpc_pipe_ops cld_upcall_ops = {
775         .upcall         = rpc_pipe_generic_upcall,
776         .downcall       = cld_pipe_downcall,
777         .destroy_msg    = cld_pipe_destroy_msg,
778 };
779 
780 static struct dentry *
781 nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
782 {
783         struct dentry *dir, *dentry;
784 
785         dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
786         if (dir == NULL)
787                 return ERR_PTR(-ENOENT);
788         dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
789         dput(dir);
790         return dentry;
791 }
792 
793 static void
794 nfsd4_cld_unregister_sb(struct rpc_pipe *pipe)
795 {
796         if (pipe->dentry)
797                 rpc_unlink(pipe->dentry);
798 }
799 
800 static struct dentry *
801 nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
802 {
803         struct super_block *sb;
804         struct dentry *dentry;
805 
806         sb = rpc_get_sb_net(net);
807         if (!sb)
808                 return NULL;
809         dentry = nfsd4_cld_register_sb(sb, pipe);
810         rpc_put_sb_net(net);
811         return dentry;
812 }
813 
814 static void
815 nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
816 {
817         struct super_block *sb;
818 
819         sb = rpc_get_sb_net(net);
820         if (sb) {
821                 nfsd4_cld_unregister_sb(pipe);
822                 rpc_put_sb_net(net);
823         }
824 }
825 
826 /* Initialize rpc_pipefs pipe for communication with client tracking daemon */
827 static int
828 nfsd4_init_cld_pipe(struct net *net)
829 {
830         int ret;
831         struct dentry *dentry;
832         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
833         struct cld_net *cn;
834 
835         if (nn->cld_net)
836                 return 0;
837 
838         cn = kzalloc(sizeof(*cn), GFP_KERNEL);
839         if (!cn) {
840                 ret = -ENOMEM;
841                 goto err;
842         }
843 
844         cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
845         if (IS_ERR(cn->cn_pipe)) {
846                 ret = PTR_ERR(cn->cn_pipe);
847                 goto err;
848         }
849         spin_lock_init(&cn->cn_lock);
850         INIT_LIST_HEAD(&cn->cn_list);
851 
852         dentry = nfsd4_cld_register_net(net, cn->cn_pipe);
853         if (IS_ERR(dentry)) {
854                 ret = PTR_ERR(dentry);
855                 goto err_destroy_data;
856         }
857 
858         cn->cn_pipe->dentry = dentry;
859         nn->cld_net = cn;
860         return 0;
861 
862 err_destroy_data:
863         rpc_destroy_pipe_data(cn->cn_pipe);
864 err:
865         kfree(cn);
866         printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
867                         ret);
868         return ret;
869 }
870 
871 static void
872 nfsd4_remove_cld_pipe(struct net *net)
873 {
874         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
875         struct cld_net *cn = nn->cld_net;
876 
877         nfsd4_cld_unregister_net(net, cn->cn_pipe);
878         rpc_destroy_pipe_data(cn->cn_pipe);
879         kfree(nn->cld_net);
880         nn->cld_net = NULL;
881 }
882 
883 static struct cld_upcall *
884 alloc_cld_upcall(struct cld_net *cn)
885 {
886         struct cld_upcall *new, *tmp;
887 
888         new = kzalloc(sizeof(*new), GFP_KERNEL);
889         if (!new)
890                 return new;
891 
892         /* FIXME: hard cap on number in flight? */
893 restart_search:
894         spin_lock(&cn->cn_lock);
895         list_for_each_entry(tmp, &cn->cn_list, cu_list) {
896                 if (tmp->cu_msg.cm_xid == cn->cn_xid) {
897                         cn->cn_xid++;
898                         spin_unlock(&cn->cn_lock);
899                         goto restart_search;
900                 }
901         }
902         new->cu_task = current;
903         new->cu_msg.cm_vers = CLD_UPCALL_VERSION;
904         put_unaligned(cn->cn_xid++, &new->cu_msg.cm_xid);
905         new->cu_net = cn;
906         list_add(&new->cu_list, &cn->cn_list);
907         spin_unlock(&cn->cn_lock);
908 
909         dprintk("%s: allocated xid %u\n", __func__, new->cu_msg.cm_xid);
910 
911         return new;
912 }
913 
914 static void
915 free_cld_upcall(struct cld_upcall *victim)
916 {
917         struct cld_net *cn = victim->cu_net;
918 
919         spin_lock(&cn->cn_lock);
920         list_del(&victim->cu_list);
921         spin_unlock(&cn->cn_lock);
922         kfree(victim);
923 }
924 
925 /* Ask daemon to create a new record */
926 static void
927 nfsd4_cld_create(struct nfs4_client *clp)
928 {
929         int ret;
930         struct cld_upcall *cup;
931         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
932         struct cld_net *cn = nn->cld_net;
933 
934         /* Don't upcall if it's already stored */
935         if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
936                 return;
937 
938         cup = alloc_cld_upcall(cn);
939         if (!cup) {
940                 ret = -ENOMEM;
941                 goto out_err;
942         }
943 
944         cup->cu_msg.cm_cmd = Cld_Create;
945         cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
946         memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
947                         clp->cl_name.len);
948 
949         ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
950         if (!ret) {
951                 ret = cup->cu_msg.cm_status;
952                 set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
953         }
954 
955         free_cld_upcall(cup);
956 out_err:
957         if (ret)
958                 printk(KERN_ERR "NFSD: Unable to create client "
959                                 "record on stable storage: %d\n", ret);
960 }
961 
962 /* Ask daemon to create a new record */
963 static void
964 nfsd4_cld_remove(struct nfs4_client *clp)
965 {
966         int ret;
967         struct cld_upcall *cup;
968         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
969         struct cld_net *cn = nn->cld_net;
970 
971         /* Don't upcall if it's already removed */
972         if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
973                 return;
974 
975         cup = alloc_cld_upcall(cn);
976         if (!cup) {
977                 ret = -ENOMEM;
978                 goto out_err;
979         }
980 
981         cup->cu_msg.cm_cmd = Cld_Remove;
982         cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
983         memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
984                         clp->cl_name.len);
985 
986         ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
987         if (!ret) {
988                 ret = cup->cu_msg.cm_status;
989                 clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
990         }
991 
992         free_cld_upcall(cup);
993 out_err:
994         if (ret)
995                 printk(KERN_ERR "NFSD: Unable to remove client "
996                                 "record from stable storage: %d\n", ret);
997 }
998 
999 /* Check for presence of a record, and update its timestamp */
1000 static int
1001 nfsd4_cld_check(struct nfs4_client *clp)
1002 {
1003         int ret;
1004         struct cld_upcall *cup;
1005         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1006         struct cld_net *cn = nn->cld_net;
1007 
1008         /* Don't upcall if one was already stored during this grace pd */
1009         if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1010                 return 0;
1011 
1012         cup = alloc_cld_upcall(cn);
1013         if (!cup) {
1014                 printk(KERN_ERR "NFSD: Unable to check client record on "
1015                                 "stable storage: %d\n", -ENOMEM);
1016                 return -ENOMEM;
1017         }
1018 
1019         cup->cu_msg.cm_cmd = Cld_Check;
1020         cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1021         memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1022                         clp->cl_name.len);
1023 
1024         ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
1025         if (!ret) {
1026                 ret = cup->cu_msg.cm_status;
1027                 set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1028         }
1029 
1030         free_cld_upcall(cup);
1031         return ret;
1032 }
1033 
1034 static void
1035 nfsd4_cld_grace_done(struct nfsd_net *nn)
1036 {
1037         int ret;
1038         struct cld_upcall *cup;
1039         struct cld_net *cn = nn->cld_net;
1040 
1041         cup = alloc_cld_upcall(cn);
1042         if (!cup) {
1043                 ret = -ENOMEM;
1044                 goto out_err;
1045         }
1046 
1047         cup->cu_msg.cm_cmd = Cld_GraceDone;
1048         cup->cu_msg.cm_u.cm_gracetime = (int64_t)nn->boot_time;
1049         ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
1050         if (!ret)
1051                 ret = cup->cu_msg.cm_status;
1052 
1053         free_cld_upcall(cup);
1054 out_err:
1055         if (ret)
1056                 printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1057 }
1058 
1059 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
1060         .init           = nfsd4_init_cld_pipe,
1061         .exit           = nfsd4_remove_cld_pipe,
1062         .create         = nfsd4_cld_create,
1063         .remove         = nfsd4_cld_remove,
1064         .check          = nfsd4_cld_check,
1065         .grace_done     = nfsd4_cld_grace_done,
1066 };
1067 
1068 /* upcall via usermodehelper */
1069 static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
1070 module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
1071                         S_IRUGO|S_IWUSR);
1072 MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
1073 
1074 static bool cltrack_legacy_disable;
1075 module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
1076 MODULE_PARM_DESC(cltrack_legacy_disable,
1077                 "Disable legacy recoverydir conversion. Default: false");
1078 
1079 #define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
1080 #define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
1081 #define HAS_SESSION_ENV_PREFIX "NFSDCLTRACK_CLIENT_HAS_SESSION="
1082 #define GRACE_START_ENV_PREFIX "NFSDCLTRACK_GRACE_START="
1083 
1084 static char *
1085 nfsd4_cltrack_legacy_topdir(void)
1086 {
1087         int copied;
1088         size_t len;
1089         char *result;
1090 
1091         if (cltrack_legacy_disable)
1092                 return NULL;
1093 
1094         len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
1095                 strlen(nfs4_recoverydir()) + 1;
1096 
1097         result = kmalloc(len, GFP_KERNEL);
1098         if (!result)
1099                 return result;
1100 
1101         copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
1102                                 nfs4_recoverydir());
1103         if (copied >= len) {
1104                 /* just return nothing if output was truncated */
1105                 kfree(result);
1106                 return NULL;
1107         }
1108 
1109         return result;
1110 }
1111 
1112 static char *
1113 nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
1114 {
1115         int copied;
1116         size_t len;
1117         char *result;
1118 
1119         if (cltrack_legacy_disable)
1120                 return NULL;
1121 
1122         /* +1 is for '/' between "topdir" and "recdir" */
1123         len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
1124                 strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
1125 
1126         result = kmalloc(len, GFP_KERNEL);
1127         if (!result)
1128                 return result;
1129 
1130         copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
1131                                 nfs4_recoverydir());
1132         if (copied > (len - HEXDIR_LEN)) {
1133                 /* just return nothing if output will be truncated */
1134                 kfree(result);
1135                 return NULL;
1136         }
1137 
1138         copied = nfs4_make_rec_clidname(result + copied, name);
1139         if (copied) {
1140                 kfree(result);
1141                 return NULL;
1142         }
1143 
1144         return result;
1145 }
1146 
1147 static char *
1148 nfsd4_cltrack_client_has_session(struct nfs4_client *clp)
1149 {
1150         int copied;
1151         size_t len;
1152         char *result;
1153 
1154         /* prefix + Y/N character + terminating NULL */
1155         len = strlen(HAS_SESSION_ENV_PREFIX) + 1 + 1;
1156 
1157         result = kmalloc(len, GFP_KERNEL);
1158         if (!result)
1159                 return result;
1160 
1161         copied = snprintf(result, len, HAS_SESSION_ENV_PREFIX "%c",
1162                                 clp->cl_minorversion ? 'Y' : 'N');
1163         if (copied >= len) {
1164                 /* just return nothing if output was truncated */
1165                 kfree(result);
1166                 return NULL;
1167         }
1168 
1169         return result;
1170 }
1171 
1172 static char *
1173 nfsd4_cltrack_grace_start(time_t grace_start)
1174 {
1175         int copied;
1176         size_t len;
1177         char *result;
1178 
1179         /* prefix + max width of int64_t string + terminating NULL */
1180         len = strlen(GRACE_START_ENV_PREFIX) + 22 + 1;
1181 
1182         result = kmalloc(len, GFP_KERNEL);
1183         if (!result)
1184                 return result;
1185 
1186         copied = snprintf(result, len, GRACE_START_ENV_PREFIX "%ld",
1187                                 grace_start);
1188         if (copied >= len) {
1189                 /* just return nothing if output was truncated */
1190                 kfree(result);
1191                 return NULL;
1192         }
1193 
1194         return result;
1195 }
1196 
1197 static int
1198 nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
1199 {
1200         char *envp[3];
1201         char *argv[4];
1202         int ret;
1203 
1204         if (unlikely(!cltrack_prog[0])) {
1205                 dprintk("%s: cltrack_prog is disabled\n", __func__);
1206                 return -EACCES;
1207         }
1208 
1209         dprintk("%s: cmd: %s\n", __func__, cmd);
1210         dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
1211         dprintk("%s: env0: %s\n", __func__, env0 ? env0 : "(null)");
1212         dprintk("%s: env1: %s\n", __func__, env1 ? env1 : "(null)");
1213 
1214         envp[0] = env0;
1215         envp[1] = env1;
1216         envp[2] = NULL;
1217 
1218         argv[0] = (char *)cltrack_prog;
1219         argv[1] = cmd;
1220         argv[2] = arg;
1221         argv[3] = NULL;
1222 
1223         ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
1224         /*
1225          * Disable the upcall mechanism if we're getting an ENOENT or EACCES
1226          * error. The admin can re-enable it on the fly by using sysfs
1227          * once the problem has been fixed.
1228          */
1229         if (ret == -ENOENT || ret == -EACCES) {
1230                 dprintk("NFSD: %s was not found or isn't executable (%d). "
1231                         "Setting cltrack_prog to blank string!",
1232                         cltrack_prog, ret);
1233                 cltrack_prog[0] = '\0';
1234         }
1235         dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
1236 
1237         return ret;
1238 }
1239 
1240 static char *
1241 bin_to_hex_dup(const unsigned char *src, int srclen)
1242 {
1243         int i;
1244         char *buf, *hex;
1245 
1246         /* +1 for terminating NULL */
1247         buf = kmalloc((srclen * 2) + 1, GFP_KERNEL);
1248         if (!buf)
1249                 return buf;
1250 
1251         hex = buf;
1252         for (i = 0; i < srclen; i++) {
1253                 sprintf(hex, "%2.2x", *src++);
1254                 hex += 2;
1255         }
1256         return buf;
1257 }
1258 
1259 static int
1260 nfsd4_umh_cltrack_init(struct net *net)
1261 {
1262         int ret;
1263         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1264         char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1265 
1266         /* XXX: The usermode helper s not working in container yet. */
1267         if (net != &init_net) {
1268                 pr_warn("NFSD: attempt to initialize umh client tracking in a container ignored.\n");
1269                 kfree(grace_start);
1270                 return -EINVAL;
1271         }
1272 
1273         ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
1274         kfree(grace_start);
1275         return ret;
1276 }
1277 
1278 static void
1279 nfsd4_cltrack_upcall_lock(struct nfs4_client *clp)
1280 {
1281         wait_on_bit_lock(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK,
1282                          TASK_UNINTERRUPTIBLE);
1283 }
1284 
1285 static void
1286 nfsd4_cltrack_upcall_unlock(struct nfs4_client *clp)
1287 {
1288         smp_mb__before_atomic();
1289         clear_bit(NFSD4_CLIENT_UPCALL_LOCK, &clp->cl_flags);
1290         smp_mb__after_atomic();
1291         wake_up_bit(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK);
1292 }
1293 
1294 static void
1295 nfsd4_umh_cltrack_create(struct nfs4_client *clp)
1296 {
1297         char *hexid, *has_session, *grace_start;
1298         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1299 
1300         /*
1301          * With v4.0 clients, there's little difference in outcome between a
1302          * create and check operation, and we can end up calling into this
1303          * function multiple times per client (once for each openowner). So,
1304          * for v4.0 clients skip upcalling once the client has been recorded
1305          * on stable storage.
1306          *
1307          * For v4.1+ clients, the outcome of the two operations is different,
1308          * so we must ensure that we upcall for the create operation. v4.1+
1309          * clients call this on RECLAIM_COMPLETE though, so we should only end
1310          * up doing a single create upcall per client.
1311          */
1312         if (clp->cl_minorversion == 0 &&
1313             test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1314                 return;
1315 
1316         hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1317         if (!hexid) {
1318                 dprintk("%s: can't allocate memory for upcall!\n", __func__);
1319                 return;
1320         }
1321 
1322         has_session = nfsd4_cltrack_client_has_session(clp);
1323         grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1324 
1325         nfsd4_cltrack_upcall_lock(clp);
1326         if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
1327                 set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1328         nfsd4_cltrack_upcall_unlock(clp);
1329 
1330         kfree(has_session);
1331         kfree(grace_start);
1332         kfree(hexid);
1333 }
1334 
1335 static void
1336 nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
1337 {
1338         char *hexid;
1339 
1340         if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1341                 return;
1342 
1343         hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1344         if (!hexid) {
1345                 dprintk("%s: can't allocate memory for upcall!\n", __func__);
1346                 return;
1347         }
1348 
1349         nfsd4_cltrack_upcall_lock(clp);
1350         if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
1351             nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
1352                 clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1353         nfsd4_cltrack_upcall_unlock(clp);
1354 
1355         kfree(hexid);
1356 }
1357 
1358 static int
1359 nfsd4_umh_cltrack_check(struct nfs4_client *clp)
1360 {
1361         int ret;
1362         char *hexid, *has_session, *legacy;
1363 
1364         if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1365                 return 0;
1366 
1367         hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1368         if (!hexid) {
1369                 dprintk("%s: can't allocate memory for upcall!\n", __func__);
1370                 return -ENOMEM;
1371         }
1372 
1373         has_session = nfsd4_cltrack_client_has_session(clp);
1374         legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
1375 
1376         nfsd4_cltrack_upcall_lock(clp);
1377         if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
1378                 ret = 0;
1379         } else {
1380                 ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
1381                 if (ret == 0)
1382                         set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1383         }
1384         nfsd4_cltrack_upcall_unlock(clp);
1385         kfree(has_session);
1386         kfree(legacy);
1387         kfree(hexid);
1388 
1389         return ret;
1390 }
1391 
1392 static void
1393 nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)
1394 {
1395         char *legacy;
1396         char timestr[22]; /* FIXME: better way to determine max size? */
1397 
1398         sprintf(timestr, "%ld", nn->boot_time);
1399         legacy = nfsd4_cltrack_legacy_topdir();
1400         nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
1401         kfree(legacy);
1402 }
1403 
1404 static const struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
1405         .init           = nfsd4_umh_cltrack_init,
1406         .exit           = NULL,
1407         .create         = nfsd4_umh_cltrack_create,
1408         .remove         = nfsd4_umh_cltrack_remove,
1409         .check          = nfsd4_umh_cltrack_check,
1410         .grace_done     = nfsd4_umh_cltrack_grace_done,
1411 };
1412 
1413 int
1414 nfsd4_client_tracking_init(struct net *net)
1415 {
1416         int status;
1417         struct path path;
1418         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1419 
1420         /* just run the init if it the method is already decided */
1421         if (nn->client_tracking_ops)
1422                 goto do_init;
1423 
1424         /*
1425          * First, try a UMH upcall. It should succeed or fail quickly, so
1426          * there's little harm in trying that first.
1427          */
1428         nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
1429         status = nn->client_tracking_ops->init(net);
1430         if (!status)
1431                 return status;
1432 
1433         /*
1434          * See if the recoverydir exists and is a directory. If it is,
1435          * then use the legacy ops.
1436          */
1437         nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
1438         status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
1439         if (!status) {
1440                 status = d_is_dir(path.dentry);
1441                 path_put(&path);
1442                 if (status)
1443                         goto do_init;
1444         }
1445 
1446         /* Finally, try to use nfsdcld */
1447         nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
1448         printk(KERN_WARNING "NFSD: the nfsdcld client tracking upcall will be "
1449                         "removed in 3.10. Please transition to using "
1450                         "nfsdcltrack.\n");
1451 do_init:
1452         status = nn->client_tracking_ops->init(net);
1453         if (status) {
1454                 printk(KERN_WARNING "NFSD: Unable to initialize client "
1455                                     "recovery tracking! (%d)\n", status);
1456                 nn->client_tracking_ops = NULL;
1457         }
1458         return status;
1459 }
1460 
1461 void
1462 nfsd4_client_tracking_exit(struct net *net)
1463 {
1464         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1465 
1466         if (nn->client_tracking_ops) {
1467                 if (nn->client_tracking_ops->exit)
1468                         nn->client_tracking_ops->exit(net);
1469                 nn->client_tracking_ops = NULL;
1470         }
1471 }
1472 
1473 void
1474 nfsd4_client_record_create(struct nfs4_client *clp)
1475 {
1476         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1477 
1478         if (nn->client_tracking_ops)
1479                 nn->client_tracking_ops->create(clp);
1480 }
1481 
1482 void
1483 nfsd4_client_record_remove(struct nfs4_client *clp)
1484 {
1485         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1486 
1487         if (nn->client_tracking_ops)
1488                 nn->client_tracking_ops->remove(clp);
1489 }
1490 
1491 int
1492 nfsd4_client_record_check(struct nfs4_client *clp)
1493 {
1494         struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1495 
1496         if (nn->client_tracking_ops)
1497                 return nn->client_tracking_ops->check(clp);
1498 
1499         return -EOPNOTSUPP;
1500 }
1501 
1502 void
1503 nfsd4_record_grace_done(struct nfsd_net *nn)
1504 {
1505         if (nn->client_tracking_ops)
1506                 nn->client_tracking_ops->grace_done(nn);
1507 }
1508 
1509 static int
1510 rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
1511 {
1512         struct super_block *sb = ptr;
1513         struct net *net = sb->s_fs_info;
1514         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1515         struct cld_net *cn = nn->cld_net;
1516         struct dentry *dentry;
1517         int ret = 0;
1518 
1519         if (!try_module_get(THIS_MODULE))
1520                 return 0;
1521 
1522         if (!cn) {
1523                 module_put(THIS_MODULE);
1524                 return 0;
1525         }
1526 
1527         switch (event) {
1528         case RPC_PIPEFS_MOUNT:
1529                 dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
1530                 if (IS_ERR(dentry)) {
1531                         ret = PTR_ERR(dentry);
1532                         break;
1533                 }
1534                 cn->cn_pipe->dentry = dentry;
1535                 break;
1536         case RPC_PIPEFS_UMOUNT:
1537                 if (cn->cn_pipe->dentry)
1538                         nfsd4_cld_unregister_sb(cn->cn_pipe);
1539                 break;
1540         default:
1541                 ret = -ENOTSUPP;
1542                 break;
1543         }
1544         module_put(THIS_MODULE);
1545         return ret;
1546 }
1547 
1548 static struct notifier_block nfsd4_cld_block = {
1549         .notifier_call = rpc_pipefs_event,
1550 };
1551 
1552 int
1553 register_cld_notifier(void)
1554 {
1555         return rpc_pipefs_notifier_register(&nfsd4_cld_block);
1556 }
1557 
1558 void
1559 unregister_cld_notifier(void)
1560 {
1561         rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
1562 }
1563 

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