Merge tag 'acpi-5.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
[sfrench/cifs-2.6.git] / net / sunrpc / rpc_pipe.c
1 /*
2  * net/sunrpc/rpc_pipe.c
3  *
4  * Userland/kernel interface for rpcauth_gss.
5  * Code shamelessly plagiarized from fs/nfsd/nfsctl.c
6  * and fs/sysfs/inode.c
7  *
8  * Copyright (c) 2002, Trond Myklebust <trond.myklebust@fys.uio.no>
9  *
10  */
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/string.h>
14 #include <linux/pagemap.h>
15 #include <linux/mount.h>
16 #include <linux/namei.h>
17 #include <linux/fsnotify.h>
18 #include <linux/kernel.h>
19 #include <linux/rcupdate.h>
20 #include <linux/utsname.h>
21
22 #include <asm/ioctls.h>
23 #include <linux/poll.h>
24 #include <linux/wait.h>
25 #include <linux/seq_file.h>
26
27 #include <linux/sunrpc/clnt.h>
28 #include <linux/workqueue.h>
29 #include <linux/sunrpc/rpc_pipe_fs.h>
30 #include <linux/sunrpc/cache.h>
31 #include <linux/nsproxy.h>
32 #include <linux/notifier.h>
33
34 #include "netns.h"
35 #include "sunrpc.h"
36
37 #define RPCDBG_FACILITY RPCDBG_DEBUG
38
39 #define NET_NAME(net)   ((net == &init_net) ? " (init_net)" : "")
40
41 static struct file_system_type rpc_pipe_fs_type;
42 static const struct rpc_pipe_ops gssd_dummy_pipe_ops;
43
44 static struct kmem_cache *rpc_inode_cachep __read_mostly;
45
46 #define RPC_UPCALL_TIMEOUT (30*HZ)
47
48 static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
49
50 int rpc_pipefs_notifier_register(struct notifier_block *nb)
51 {
52         return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb);
53 }
54 EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
55
56 void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
57 {
58         blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
59 }
60 EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
61
62 static void rpc_purge_list(wait_queue_head_t *waitq, struct list_head *head,
63                 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
64 {
65         struct rpc_pipe_msg *msg;
66
67         if (list_empty(head))
68                 return;
69         do {
70                 msg = list_entry(head->next, struct rpc_pipe_msg, list);
71                 list_del_init(&msg->list);
72                 msg->errno = err;
73                 destroy_msg(msg);
74         } while (!list_empty(head));
75
76         if (waitq)
77                 wake_up(waitq);
78 }
79
80 static void
81 rpc_timeout_upcall_queue(struct work_struct *work)
82 {
83         LIST_HEAD(free_list);
84         struct rpc_pipe *pipe =
85                 container_of(work, struct rpc_pipe, queue_timeout.work);
86         void (*destroy_msg)(struct rpc_pipe_msg *);
87         struct dentry *dentry;
88
89         spin_lock(&pipe->lock);
90         destroy_msg = pipe->ops->destroy_msg;
91         if (pipe->nreaders == 0) {
92                 list_splice_init(&pipe->pipe, &free_list);
93                 pipe->pipelen = 0;
94         }
95         dentry = dget(pipe->dentry);
96         spin_unlock(&pipe->lock);
97         rpc_purge_list(dentry ? &RPC_I(d_inode(dentry))->waitq : NULL,
98                         &free_list, destroy_msg, -ETIMEDOUT);
99         dput(dentry);
100 }
101
102 ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
103                                 char __user *dst, size_t buflen)
104 {
105         char *data = (char *)msg->data + msg->copied;
106         size_t mlen = min(msg->len - msg->copied, buflen);
107         unsigned long left;
108
109         left = copy_to_user(dst, data, mlen);
110         if (left == mlen) {
111                 msg->errno = -EFAULT;
112                 return -EFAULT;
113         }
114
115         mlen -= left;
116         msg->copied += mlen;
117         msg->errno = 0;
118         return mlen;
119 }
120 EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
121
122 /**
123  * rpc_queue_upcall - queue an upcall message to userspace
124  * @pipe: upcall pipe on which to queue given message
125  * @msg: message to queue
126  *
127  * Call with an @inode created by rpc_mkpipe() to queue an upcall.
128  * A userspace process may then later read the upcall by performing a
129  * read on an open file for this inode.  It is up to the caller to
130  * initialize the fields of @msg (other than @msg->list) appropriately.
131  */
132 int
133 rpc_queue_upcall(struct rpc_pipe *pipe, struct rpc_pipe_msg *msg)
134 {
135         int res = -EPIPE;
136         struct dentry *dentry;
137
138         spin_lock(&pipe->lock);
139         if (pipe->nreaders) {
140                 list_add_tail(&msg->list, &pipe->pipe);
141                 pipe->pipelen += msg->len;
142                 res = 0;
143         } else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
144                 if (list_empty(&pipe->pipe))
145                         queue_delayed_work(rpciod_workqueue,
146                                         &pipe->queue_timeout,
147                                         RPC_UPCALL_TIMEOUT);
148                 list_add_tail(&msg->list, &pipe->pipe);
149                 pipe->pipelen += msg->len;
150                 res = 0;
151         }
152         dentry = dget(pipe->dentry);
153         spin_unlock(&pipe->lock);
154         if (dentry) {
155                 wake_up(&RPC_I(d_inode(dentry))->waitq);
156                 dput(dentry);
157         }
158         return res;
159 }
160 EXPORT_SYMBOL_GPL(rpc_queue_upcall);
161
162 static inline void
163 rpc_inode_setowner(struct inode *inode, void *private)
164 {
165         RPC_I(inode)->private = private;
166 }
167
168 static void
169 rpc_close_pipes(struct inode *inode)
170 {
171         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
172         int need_release;
173         LIST_HEAD(free_list);
174
175         inode_lock(inode);
176         spin_lock(&pipe->lock);
177         need_release = pipe->nreaders != 0 || pipe->nwriters != 0;
178         pipe->nreaders = 0;
179         list_splice_init(&pipe->in_upcall, &free_list);
180         list_splice_init(&pipe->pipe, &free_list);
181         pipe->pipelen = 0;
182         pipe->dentry = NULL;
183         spin_unlock(&pipe->lock);
184         rpc_purge_list(&RPC_I(inode)->waitq, &free_list, pipe->ops->destroy_msg, -EPIPE);
185         pipe->nwriters = 0;
186         if (need_release && pipe->ops->release_pipe)
187                 pipe->ops->release_pipe(inode);
188         cancel_delayed_work_sync(&pipe->queue_timeout);
189         rpc_inode_setowner(inode, NULL);
190         RPC_I(inode)->pipe = NULL;
191         inode_unlock(inode);
192 }
193
194 static struct inode *
195 rpc_alloc_inode(struct super_block *sb)
196 {
197         struct rpc_inode *rpci;
198         rpci = kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
199         if (!rpci)
200                 return NULL;
201         return &rpci->vfs_inode;
202 }
203
204 static void
205 rpc_i_callback(struct rcu_head *head)
206 {
207         struct inode *inode = container_of(head, struct inode, i_rcu);
208         kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
209 }
210
211 static void
212 rpc_destroy_inode(struct inode *inode)
213 {
214         call_rcu(&inode->i_rcu, rpc_i_callback);
215 }
216
217 static int
218 rpc_pipe_open(struct inode *inode, struct file *filp)
219 {
220         struct rpc_pipe *pipe;
221         int first_open;
222         int res = -ENXIO;
223
224         inode_lock(inode);
225         pipe = RPC_I(inode)->pipe;
226         if (pipe == NULL)
227                 goto out;
228         first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
229         if (first_open && pipe->ops->open_pipe) {
230                 res = pipe->ops->open_pipe(inode);
231                 if (res)
232                         goto out;
233         }
234         if (filp->f_mode & FMODE_READ)
235                 pipe->nreaders++;
236         if (filp->f_mode & FMODE_WRITE)
237                 pipe->nwriters++;
238         res = 0;
239 out:
240         inode_unlock(inode);
241         return res;
242 }
243
244 static int
245 rpc_pipe_release(struct inode *inode, struct file *filp)
246 {
247         struct rpc_pipe *pipe;
248         struct rpc_pipe_msg *msg;
249         int last_close;
250
251         inode_lock(inode);
252         pipe = RPC_I(inode)->pipe;
253         if (pipe == NULL)
254                 goto out;
255         msg = filp->private_data;
256         if (msg != NULL) {
257                 spin_lock(&pipe->lock);
258                 msg->errno = -EAGAIN;
259                 list_del_init(&msg->list);
260                 spin_unlock(&pipe->lock);
261                 pipe->ops->destroy_msg(msg);
262         }
263         if (filp->f_mode & FMODE_WRITE)
264                 pipe->nwriters --;
265         if (filp->f_mode & FMODE_READ) {
266                 pipe->nreaders --;
267                 if (pipe->nreaders == 0) {
268                         LIST_HEAD(free_list);
269                         spin_lock(&pipe->lock);
270                         list_splice_init(&pipe->pipe, &free_list);
271                         pipe->pipelen = 0;
272                         spin_unlock(&pipe->lock);
273                         rpc_purge_list(&RPC_I(inode)->waitq, &free_list,
274                                         pipe->ops->destroy_msg, -EAGAIN);
275                 }
276         }
277         last_close = pipe->nwriters == 0 && pipe->nreaders == 0;
278         if (last_close && pipe->ops->release_pipe)
279                 pipe->ops->release_pipe(inode);
280 out:
281         inode_unlock(inode);
282         return 0;
283 }
284
285 static ssize_t
286 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
287 {
288         struct inode *inode = file_inode(filp);
289         struct rpc_pipe *pipe;
290         struct rpc_pipe_msg *msg;
291         int res = 0;
292
293         inode_lock(inode);
294         pipe = RPC_I(inode)->pipe;
295         if (pipe == NULL) {
296                 res = -EPIPE;
297                 goto out_unlock;
298         }
299         msg = filp->private_data;
300         if (msg == NULL) {
301                 spin_lock(&pipe->lock);
302                 if (!list_empty(&pipe->pipe)) {
303                         msg = list_entry(pipe->pipe.next,
304                                         struct rpc_pipe_msg,
305                                         list);
306                         list_move(&msg->list, &pipe->in_upcall);
307                         pipe->pipelen -= msg->len;
308                         filp->private_data = msg;
309                         msg->copied = 0;
310                 }
311                 spin_unlock(&pipe->lock);
312                 if (msg == NULL)
313                         goto out_unlock;
314         }
315         /* NOTE: it is up to the callback to update msg->copied */
316         res = pipe->ops->upcall(filp, msg, buf, len);
317         if (res < 0 || msg->len == msg->copied) {
318                 filp->private_data = NULL;
319                 spin_lock(&pipe->lock);
320                 list_del_init(&msg->list);
321                 spin_unlock(&pipe->lock);
322                 pipe->ops->destroy_msg(msg);
323         }
324 out_unlock:
325         inode_unlock(inode);
326         return res;
327 }
328
329 static ssize_t
330 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
331 {
332         struct inode *inode = file_inode(filp);
333         int res;
334
335         inode_lock(inode);
336         res = -EPIPE;
337         if (RPC_I(inode)->pipe != NULL)
338                 res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len);
339         inode_unlock(inode);
340         return res;
341 }
342
343 static __poll_t
344 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
345 {
346         struct inode *inode = file_inode(filp);
347         struct rpc_inode *rpci = RPC_I(inode);
348         __poll_t mask = EPOLLOUT | EPOLLWRNORM;
349
350         poll_wait(filp, &rpci->waitq, wait);
351
352         inode_lock(inode);
353         if (rpci->pipe == NULL)
354                 mask |= EPOLLERR | EPOLLHUP;
355         else if (filp->private_data || !list_empty(&rpci->pipe->pipe))
356                 mask |= EPOLLIN | EPOLLRDNORM;
357         inode_unlock(inode);
358         return mask;
359 }
360
361 static long
362 rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
363 {
364         struct inode *inode = file_inode(filp);
365         struct rpc_pipe *pipe;
366         int len;
367
368         switch (cmd) {
369         case FIONREAD:
370                 inode_lock(inode);
371                 pipe = RPC_I(inode)->pipe;
372                 if (pipe == NULL) {
373                         inode_unlock(inode);
374                         return -EPIPE;
375                 }
376                 spin_lock(&pipe->lock);
377                 len = pipe->pipelen;
378                 if (filp->private_data) {
379                         struct rpc_pipe_msg *msg;
380                         msg = filp->private_data;
381                         len += msg->len - msg->copied;
382                 }
383                 spin_unlock(&pipe->lock);
384                 inode_unlock(inode);
385                 return put_user(len, (int __user *)arg);
386         default:
387                 return -EINVAL;
388         }
389 }
390
391 static const struct file_operations rpc_pipe_fops = {
392         .owner          = THIS_MODULE,
393         .llseek         = no_llseek,
394         .read           = rpc_pipe_read,
395         .write          = rpc_pipe_write,
396         .poll           = rpc_pipe_poll,
397         .unlocked_ioctl = rpc_pipe_ioctl,
398         .open           = rpc_pipe_open,
399         .release        = rpc_pipe_release,
400 };
401
402 static int
403 rpc_show_info(struct seq_file *m, void *v)
404 {
405         struct rpc_clnt *clnt = m->private;
406
407         rcu_read_lock();
408         seq_printf(m, "RPC server: %s\n",
409                         rcu_dereference(clnt->cl_xprt)->servername);
410         seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_program->name,
411                         clnt->cl_prog, clnt->cl_vers);
412         seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
413         seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
414         seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
415         rcu_read_unlock();
416         return 0;
417 }
418
419 static int
420 rpc_info_open(struct inode *inode, struct file *file)
421 {
422         struct rpc_clnt *clnt = NULL;
423         int ret = single_open(file, rpc_show_info, NULL);
424
425         if (!ret) {
426                 struct seq_file *m = file->private_data;
427
428                 spin_lock(&file->f_path.dentry->d_lock);
429                 if (!d_unhashed(file->f_path.dentry))
430                         clnt = RPC_I(inode)->private;
431                 if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) {
432                         spin_unlock(&file->f_path.dentry->d_lock);
433                         m->private = clnt;
434                 } else {
435                         spin_unlock(&file->f_path.dentry->d_lock);
436                         single_release(inode, file);
437                         ret = -EINVAL;
438                 }
439         }
440         return ret;
441 }
442
443 static int
444 rpc_info_release(struct inode *inode, struct file *file)
445 {
446         struct seq_file *m = file->private_data;
447         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
448
449         if (clnt)
450                 rpc_release_client(clnt);
451         return single_release(inode, file);
452 }
453
454 static const struct file_operations rpc_info_operations = {
455         .owner          = THIS_MODULE,
456         .open           = rpc_info_open,
457         .read           = seq_read,
458         .llseek         = seq_lseek,
459         .release        = rpc_info_release,
460 };
461
462
463 /*
464  * Description of fs contents.
465  */
466 struct rpc_filelist {
467         const char *name;
468         const struct file_operations *i_fop;
469         umode_t mode;
470 };
471
472 static struct inode *
473 rpc_get_inode(struct super_block *sb, umode_t mode)
474 {
475         struct inode *inode = new_inode(sb);
476         if (!inode)
477                 return NULL;
478         inode->i_ino = get_next_ino();
479         inode->i_mode = mode;
480         inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
481         switch (mode & S_IFMT) {
482         case S_IFDIR:
483                 inode->i_fop = &simple_dir_operations;
484                 inode->i_op = &simple_dir_inode_operations;
485                 inc_nlink(inode);
486         default:
487                 break;
488         }
489         return inode;
490 }
491
492 static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
493                                umode_t mode,
494                                const struct file_operations *i_fop,
495                                void *private)
496 {
497         struct inode *inode;
498
499         d_drop(dentry);
500         inode = rpc_get_inode(dir->i_sb, mode);
501         if (!inode)
502                 goto out_err;
503         inode->i_ino = iunique(dir->i_sb, 100);
504         if (i_fop)
505                 inode->i_fop = i_fop;
506         if (private)
507                 rpc_inode_setowner(inode, private);
508         d_add(dentry, inode);
509         return 0;
510 out_err:
511         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %pd\n",
512                         __FILE__, __func__, dentry);
513         dput(dentry);
514         return -ENOMEM;
515 }
516
517 static int __rpc_create(struct inode *dir, struct dentry *dentry,
518                         umode_t mode,
519                         const struct file_operations *i_fop,
520                         void *private)
521 {
522         int err;
523
524         err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
525         if (err)
526                 return err;
527         fsnotify_create(dir, dentry);
528         return 0;
529 }
530
531 static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
532                        umode_t mode,
533                        const struct file_operations *i_fop,
534                        void *private)
535 {
536         int err;
537
538         err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
539         if (err)
540                 return err;
541         inc_nlink(dir);
542         fsnotify_mkdir(dir, dentry);
543         return 0;
544 }
545
546 static void
547 init_pipe(struct rpc_pipe *pipe)
548 {
549         pipe->nreaders = 0;
550         pipe->nwriters = 0;
551         INIT_LIST_HEAD(&pipe->in_upcall);
552         INIT_LIST_HEAD(&pipe->in_downcall);
553         INIT_LIST_HEAD(&pipe->pipe);
554         pipe->pipelen = 0;
555         INIT_DELAYED_WORK(&pipe->queue_timeout,
556                             rpc_timeout_upcall_queue);
557         pipe->ops = NULL;
558         spin_lock_init(&pipe->lock);
559         pipe->dentry = NULL;
560 }
561
562 void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
563 {
564         kfree(pipe);
565 }
566 EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
567
568 struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
569 {
570         struct rpc_pipe *pipe;
571
572         pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
573         if (!pipe)
574                 return ERR_PTR(-ENOMEM);
575         init_pipe(pipe);
576         pipe->ops = ops;
577         pipe->flags = flags;
578         return pipe;
579 }
580 EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
581
582 static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
583                                umode_t mode,
584                                const struct file_operations *i_fop,
585                                void *private,
586                                struct rpc_pipe *pipe)
587 {
588         struct rpc_inode *rpci;
589         int err;
590
591         err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
592         if (err)
593                 return err;
594         rpci = RPC_I(d_inode(dentry));
595         rpci->private = private;
596         rpci->pipe = pipe;
597         fsnotify_create(dir, dentry);
598         return 0;
599 }
600
601 static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
602 {
603         int ret;
604
605         dget(dentry);
606         ret = simple_rmdir(dir, dentry);
607         d_delete(dentry);
608         dput(dentry);
609         return ret;
610 }
611
612 static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
613 {
614         int ret;
615
616         dget(dentry);
617         ret = simple_unlink(dir, dentry);
618         d_delete(dentry);
619         dput(dentry);
620         return ret;
621 }
622
623 static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
624 {
625         struct inode *inode = d_inode(dentry);
626
627         rpc_close_pipes(inode);
628         return __rpc_unlink(dir, dentry);
629 }
630
631 static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
632                                           const char *name)
633 {
634         struct qstr q = QSTR_INIT(name, strlen(name));
635         struct dentry *dentry = d_hash_and_lookup(parent, &q);
636         if (!dentry) {
637                 dentry = d_alloc(parent, &q);
638                 if (!dentry)
639                         return ERR_PTR(-ENOMEM);
640         }
641         if (d_really_is_negative(dentry))
642                 return dentry;
643         dput(dentry);
644         return ERR_PTR(-EEXIST);
645 }
646
647 /*
648  * FIXME: This probably has races.
649  */
650 static void __rpc_depopulate(struct dentry *parent,
651                              const struct rpc_filelist *files,
652                              int start, int eof)
653 {
654         struct inode *dir = d_inode(parent);
655         struct dentry *dentry;
656         struct qstr name;
657         int i;
658
659         for (i = start; i < eof; i++) {
660                 name.name = files[i].name;
661                 name.len = strlen(files[i].name);
662                 dentry = d_hash_and_lookup(parent, &name);
663
664                 if (dentry == NULL)
665                         continue;
666                 if (d_really_is_negative(dentry))
667                         goto next;
668                 switch (d_inode(dentry)->i_mode & S_IFMT) {
669                         default:
670                                 BUG();
671                         case S_IFREG:
672                                 __rpc_unlink(dir, dentry);
673                                 break;
674                         case S_IFDIR:
675                                 __rpc_rmdir(dir, dentry);
676                 }
677 next:
678                 dput(dentry);
679         }
680 }
681
682 static void rpc_depopulate(struct dentry *parent,
683                            const struct rpc_filelist *files,
684                            int start, int eof)
685 {
686         struct inode *dir = d_inode(parent);
687
688         inode_lock_nested(dir, I_MUTEX_CHILD);
689         __rpc_depopulate(parent, files, start, eof);
690         inode_unlock(dir);
691 }
692
693 static int rpc_populate(struct dentry *parent,
694                         const struct rpc_filelist *files,
695                         int start, int eof,
696                         void *private)
697 {
698         struct inode *dir = d_inode(parent);
699         struct dentry *dentry;
700         int i, err;
701
702         inode_lock(dir);
703         for (i = start; i < eof; i++) {
704                 dentry = __rpc_lookup_create_exclusive(parent, files[i].name);
705                 err = PTR_ERR(dentry);
706                 if (IS_ERR(dentry))
707                         goto out_bad;
708                 switch (files[i].mode & S_IFMT) {
709                         default:
710                                 BUG();
711                         case S_IFREG:
712                                 err = __rpc_create(dir, dentry,
713                                                 files[i].mode,
714                                                 files[i].i_fop,
715                                                 private);
716                                 break;
717                         case S_IFDIR:
718                                 err = __rpc_mkdir(dir, dentry,
719                                                 files[i].mode,
720                                                 NULL,
721                                                 private);
722                 }
723                 if (err != 0)
724                         goto out_bad;
725         }
726         inode_unlock(dir);
727         return 0;
728 out_bad:
729         __rpc_depopulate(parent, files, start, eof);
730         inode_unlock(dir);
731         printk(KERN_WARNING "%s: %s failed to populate directory %pd\n",
732                         __FILE__, __func__, parent);
733         return err;
734 }
735
736 static struct dentry *rpc_mkdir_populate(struct dentry *parent,
737                 const char *name, umode_t mode, void *private,
738                 int (*populate)(struct dentry *, void *), void *args_populate)
739 {
740         struct dentry *dentry;
741         struct inode *dir = d_inode(parent);
742         int error;
743
744         inode_lock_nested(dir, I_MUTEX_PARENT);
745         dentry = __rpc_lookup_create_exclusive(parent, name);
746         if (IS_ERR(dentry))
747                 goto out;
748         error = __rpc_mkdir(dir, dentry, mode, NULL, private);
749         if (error != 0)
750                 goto out_err;
751         if (populate != NULL) {
752                 error = populate(dentry, args_populate);
753                 if (error)
754                         goto err_rmdir;
755         }
756 out:
757         inode_unlock(dir);
758         return dentry;
759 err_rmdir:
760         __rpc_rmdir(dir, dentry);
761 out_err:
762         dentry = ERR_PTR(error);
763         goto out;
764 }
765
766 static int rpc_rmdir_depopulate(struct dentry *dentry,
767                 void (*depopulate)(struct dentry *))
768 {
769         struct dentry *parent;
770         struct inode *dir;
771         int error;
772
773         parent = dget_parent(dentry);
774         dir = d_inode(parent);
775         inode_lock_nested(dir, I_MUTEX_PARENT);
776         if (depopulate != NULL)
777                 depopulate(dentry);
778         error = __rpc_rmdir(dir, dentry);
779         inode_unlock(dir);
780         dput(parent);
781         return error;
782 }
783
784 /**
785  * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
786  * @parent: dentry of directory to create new "pipe" in
787  * @name: name of pipe
788  * @private: private data to associate with the pipe, for the caller's use
789  * @pipe: &rpc_pipe containing input parameters
790  *
791  * Data is made available for userspace to read by calls to
792  * rpc_queue_upcall().  The actual reads will result in calls to
793  * @ops->upcall, which will be called with the file pointer,
794  * message, and userspace buffer to copy to.
795  *
796  * Writes can come at any time, and do not necessarily have to be
797  * responses to upcalls.  They will result in calls to @msg->downcall.
798  *
799  * The @private argument passed here will be available to all these methods
800  * from the file pointer, via RPC_I(file_inode(file))->private.
801  */
802 struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
803                                  void *private, struct rpc_pipe *pipe)
804 {
805         struct dentry *dentry;
806         struct inode *dir = d_inode(parent);
807         umode_t umode = S_IFIFO | 0600;
808         int err;
809
810         if (pipe->ops->upcall == NULL)
811                 umode &= ~0444;
812         if (pipe->ops->downcall == NULL)
813                 umode &= ~0222;
814
815         inode_lock_nested(dir, I_MUTEX_PARENT);
816         dentry = __rpc_lookup_create_exclusive(parent, name);
817         if (IS_ERR(dentry))
818                 goto out;
819         err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
820                                   private, pipe);
821         if (err)
822                 goto out_err;
823 out:
824         inode_unlock(dir);
825         return dentry;
826 out_err:
827         dentry = ERR_PTR(err);
828         printk(KERN_WARNING "%s: %s() failed to create pipe %pd/%s (errno = %d)\n",
829                         __FILE__, __func__, parent, name,
830                         err);
831         goto out;
832 }
833 EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
834
835 /**
836  * rpc_unlink - remove a pipe
837  * @dentry: dentry for the pipe, as returned from rpc_mkpipe
838  *
839  * After this call, lookups will no longer find the pipe, and any
840  * attempts to read or write using preexisting opens of the pipe will
841  * return -EPIPE.
842  */
843 int
844 rpc_unlink(struct dentry *dentry)
845 {
846         struct dentry *parent;
847         struct inode *dir;
848         int error = 0;
849
850         parent = dget_parent(dentry);
851         dir = d_inode(parent);
852         inode_lock_nested(dir, I_MUTEX_PARENT);
853         error = __rpc_rmpipe(dir, dentry);
854         inode_unlock(dir);
855         dput(parent);
856         return error;
857 }
858 EXPORT_SYMBOL_GPL(rpc_unlink);
859
860 /**
861  * rpc_init_pipe_dir_head - initialise a struct rpc_pipe_dir_head
862  * @pdh: pointer to struct rpc_pipe_dir_head
863  */
864 void rpc_init_pipe_dir_head(struct rpc_pipe_dir_head *pdh)
865 {
866         INIT_LIST_HEAD(&pdh->pdh_entries);
867         pdh->pdh_dentry = NULL;
868 }
869 EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_head);
870
871 /**
872  * rpc_init_pipe_dir_object - initialise a struct rpc_pipe_dir_object
873  * @pdo: pointer to struct rpc_pipe_dir_object
874  * @pdo_ops: pointer to const struct rpc_pipe_dir_object_ops
875  * @pdo_data: pointer to caller-defined data
876  */
877 void rpc_init_pipe_dir_object(struct rpc_pipe_dir_object *pdo,
878                 const struct rpc_pipe_dir_object_ops *pdo_ops,
879                 void *pdo_data)
880 {
881         INIT_LIST_HEAD(&pdo->pdo_head);
882         pdo->pdo_ops = pdo_ops;
883         pdo->pdo_data = pdo_data;
884 }
885 EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_object);
886
887 static int
888 rpc_add_pipe_dir_object_locked(struct net *net,
889                 struct rpc_pipe_dir_head *pdh,
890                 struct rpc_pipe_dir_object *pdo)
891 {
892         int ret = 0;
893
894         if (pdh->pdh_dentry)
895                 ret = pdo->pdo_ops->create(pdh->pdh_dentry, pdo);
896         if (ret == 0)
897                 list_add_tail(&pdo->pdo_head, &pdh->pdh_entries);
898         return ret;
899 }
900
901 static void
902 rpc_remove_pipe_dir_object_locked(struct net *net,
903                 struct rpc_pipe_dir_head *pdh,
904                 struct rpc_pipe_dir_object *pdo)
905 {
906         if (pdh->pdh_dentry)
907                 pdo->pdo_ops->destroy(pdh->pdh_dentry, pdo);
908         list_del_init(&pdo->pdo_head);
909 }
910
911 /**
912  * rpc_add_pipe_dir_object - associate a rpc_pipe_dir_object to a directory
913  * @net: pointer to struct net
914  * @pdh: pointer to struct rpc_pipe_dir_head
915  * @pdo: pointer to struct rpc_pipe_dir_object
916  *
917  */
918 int
919 rpc_add_pipe_dir_object(struct net *net,
920                 struct rpc_pipe_dir_head *pdh,
921                 struct rpc_pipe_dir_object *pdo)
922 {
923         int ret = 0;
924
925         if (list_empty(&pdo->pdo_head)) {
926                 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
927
928                 mutex_lock(&sn->pipefs_sb_lock);
929                 ret = rpc_add_pipe_dir_object_locked(net, pdh, pdo);
930                 mutex_unlock(&sn->pipefs_sb_lock);
931         }
932         return ret;
933 }
934 EXPORT_SYMBOL_GPL(rpc_add_pipe_dir_object);
935
936 /**
937  * rpc_remove_pipe_dir_object - remove a rpc_pipe_dir_object from a directory
938  * @net: pointer to struct net
939  * @pdh: pointer to struct rpc_pipe_dir_head
940  * @pdo: pointer to struct rpc_pipe_dir_object
941  *
942  */
943 void
944 rpc_remove_pipe_dir_object(struct net *net,
945                 struct rpc_pipe_dir_head *pdh,
946                 struct rpc_pipe_dir_object *pdo)
947 {
948         if (!list_empty(&pdo->pdo_head)) {
949                 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
950
951                 mutex_lock(&sn->pipefs_sb_lock);
952                 rpc_remove_pipe_dir_object_locked(net, pdh, pdo);
953                 mutex_unlock(&sn->pipefs_sb_lock);
954         }
955 }
956 EXPORT_SYMBOL_GPL(rpc_remove_pipe_dir_object);
957
958 /**
959  * rpc_find_or_alloc_pipe_dir_object
960  * @net: pointer to struct net
961  * @pdh: pointer to struct rpc_pipe_dir_head
962  * @match: match struct rpc_pipe_dir_object to data
963  * @alloc: allocate a new struct rpc_pipe_dir_object
964  * @data: user defined data for match() and alloc()
965  *
966  */
967 struct rpc_pipe_dir_object *
968 rpc_find_or_alloc_pipe_dir_object(struct net *net,
969                 struct rpc_pipe_dir_head *pdh,
970                 int (*match)(struct rpc_pipe_dir_object *, void *),
971                 struct rpc_pipe_dir_object *(*alloc)(void *),
972                 void *data)
973 {
974         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
975         struct rpc_pipe_dir_object *pdo;
976
977         mutex_lock(&sn->pipefs_sb_lock);
978         list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) {
979                 if (!match(pdo, data))
980                         continue;
981                 goto out;
982         }
983         pdo = alloc(data);
984         if (!pdo)
985                 goto out;
986         rpc_add_pipe_dir_object_locked(net, pdh, pdo);
987 out:
988         mutex_unlock(&sn->pipefs_sb_lock);
989         return pdo;
990 }
991 EXPORT_SYMBOL_GPL(rpc_find_or_alloc_pipe_dir_object);
992
993 static void
994 rpc_create_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
995 {
996         struct rpc_pipe_dir_object *pdo;
997         struct dentry *dir = pdh->pdh_dentry;
998
999         list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
1000                 pdo->pdo_ops->create(dir, pdo);
1001 }
1002
1003 static void
1004 rpc_destroy_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
1005 {
1006         struct rpc_pipe_dir_object *pdo;
1007         struct dentry *dir = pdh->pdh_dentry;
1008
1009         list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
1010                 pdo->pdo_ops->destroy(dir, pdo);
1011 }
1012
1013 enum {
1014         RPCAUTH_info,
1015         RPCAUTH_EOF
1016 };
1017
1018 static const struct rpc_filelist authfiles[] = {
1019         [RPCAUTH_info] = {
1020                 .name = "info",
1021                 .i_fop = &rpc_info_operations,
1022                 .mode = S_IFREG | 0400,
1023         },
1024 };
1025
1026 static int rpc_clntdir_populate(struct dentry *dentry, void *private)
1027 {
1028         return rpc_populate(dentry,
1029                             authfiles, RPCAUTH_info, RPCAUTH_EOF,
1030                             private);
1031 }
1032
1033 static void rpc_clntdir_depopulate(struct dentry *dentry)
1034 {
1035         rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
1036 }
1037
1038 /**
1039  * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
1040  * @dentry: the parent of new directory
1041  * @name: the name of new directory
1042  * @rpc_client: rpc client to associate with this directory
1043  *
1044  * This creates a directory at the given @path associated with
1045  * @rpc_clnt, which will contain a file named "info" with some basic
1046  * information about the client, together with any "pipes" that may
1047  * later be created using rpc_mkpipe().
1048  */
1049 struct dentry *rpc_create_client_dir(struct dentry *dentry,
1050                                    const char *name,
1051                                    struct rpc_clnt *rpc_client)
1052 {
1053         struct dentry *ret;
1054
1055         ret = rpc_mkdir_populate(dentry, name, 0555, NULL,
1056                                  rpc_clntdir_populate, rpc_client);
1057         if (!IS_ERR(ret)) {
1058                 rpc_client->cl_pipedir_objects.pdh_dentry = ret;
1059                 rpc_create_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1060         }
1061         return ret;
1062 }
1063
1064 /**
1065  * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
1066  * @rpc_client: rpc_client for the pipe
1067  */
1068 int rpc_remove_client_dir(struct rpc_clnt *rpc_client)
1069 {
1070         struct dentry *dentry = rpc_client->cl_pipedir_objects.pdh_dentry;
1071
1072         if (dentry == NULL)
1073                 return 0;
1074         rpc_destroy_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1075         rpc_client->cl_pipedir_objects.pdh_dentry = NULL;
1076         return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
1077 }
1078
1079 static const struct rpc_filelist cache_pipefs_files[3] = {
1080         [0] = {
1081                 .name = "channel",
1082                 .i_fop = &cache_file_operations_pipefs,
1083                 .mode = S_IFREG | 0600,
1084         },
1085         [1] = {
1086                 .name = "content",
1087                 .i_fop = &content_file_operations_pipefs,
1088                 .mode = S_IFREG | 0400,
1089         },
1090         [2] = {
1091                 .name = "flush",
1092                 .i_fop = &cache_flush_operations_pipefs,
1093                 .mode = S_IFREG | 0600,
1094         },
1095 };
1096
1097 static int rpc_cachedir_populate(struct dentry *dentry, void *private)
1098 {
1099         return rpc_populate(dentry,
1100                             cache_pipefs_files, 0, 3,
1101                             private);
1102 }
1103
1104 static void rpc_cachedir_depopulate(struct dentry *dentry)
1105 {
1106         rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
1107 }
1108
1109 struct dentry *rpc_create_cache_dir(struct dentry *parent, const char *name,
1110                                     umode_t umode, struct cache_detail *cd)
1111 {
1112         return rpc_mkdir_populate(parent, name, umode, NULL,
1113                         rpc_cachedir_populate, cd);
1114 }
1115
1116 void rpc_remove_cache_dir(struct dentry *dentry)
1117 {
1118         rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
1119 }
1120
1121 /*
1122  * populate the filesystem
1123  */
1124 static const struct super_operations s_ops = {
1125         .alloc_inode    = rpc_alloc_inode,
1126         .destroy_inode  = rpc_destroy_inode,
1127         .statfs         = simple_statfs,
1128 };
1129
1130 #define RPCAUTH_GSSMAGIC 0x67596969
1131
1132 /*
1133  * We have a single directory with 1 node in it.
1134  */
1135 enum {
1136         RPCAUTH_lockd,
1137         RPCAUTH_mount,
1138         RPCAUTH_nfs,
1139         RPCAUTH_portmap,
1140         RPCAUTH_statd,
1141         RPCAUTH_nfsd4_cb,
1142         RPCAUTH_cache,
1143         RPCAUTH_nfsd,
1144         RPCAUTH_gssd,
1145         RPCAUTH_RootEOF
1146 };
1147
1148 static const struct rpc_filelist files[] = {
1149         [RPCAUTH_lockd] = {
1150                 .name = "lockd",
1151                 .mode = S_IFDIR | 0555,
1152         },
1153         [RPCAUTH_mount] = {
1154                 .name = "mount",
1155                 .mode = S_IFDIR | 0555,
1156         },
1157         [RPCAUTH_nfs] = {
1158                 .name = "nfs",
1159                 .mode = S_IFDIR | 0555,
1160         },
1161         [RPCAUTH_portmap] = {
1162                 .name = "portmap",
1163                 .mode = S_IFDIR | 0555,
1164         },
1165         [RPCAUTH_statd] = {
1166                 .name = "statd",
1167                 .mode = S_IFDIR | 0555,
1168         },
1169         [RPCAUTH_nfsd4_cb] = {
1170                 .name = "nfsd4_cb",
1171                 .mode = S_IFDIR | 0555,
1172         },
1173         [RPCAUTH_cache] = {
1174                 .name = "cache",
1175                 .mode = S_IFDIR | 0555,
1176         },
1177         [RPCAUTH_nfsd] = {
1178                 .name = "nfsd",
1179                 .mode = S_IFDIR | 0555,
1180         },
1181         [RPCAUTH_gssd] = {
1182                 .name = "gssd",
1183                 .mode = S_IFDIR | 0555,
1184         },
1185 };
1186
1187 /*
1188  * This call can be used only in RPC pipefs mount notification hooks.
1189  */
1190 struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
1191                                const unsigned char *dir_name)
1192 {
1193         struct qstr dir = QSTR_INIT(dir_name, strlen(dir_name));
1194         return d_hash_and_lookup(sb->s_root, &dir);
1195 }
1196 EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
1197
1198 int rpc_pipefs_init_net(struct net *net)
1199 {
1200         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1201
1202         sn->gssd_dummy = rpc_mkpipe_data(&gssd_dummy_pipe_ops, 0);
1203         if (IS_ERR(sn->gssd_dummy))
1204                 return PTR_ERR(sn->gssd_dummy);
1205
1206         mutex_init(&sn->pipefs_sb_lock);
1207         sn->pipe_version = -1;
1208         return 0;
1209 }
1210
1211 void rpc_pipefs_exit_net(struct net *net)
1212 {
1213         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1214
1215         rpc_destroy_pipe_data(sn->gssd_dummy);
1216 }
1217
1218 /*
1219  * This call will be used for per network namespace operations calls.
1220  * Note: Function will be returned with pipefs_sb_lock taken if superblock was
1221  * found. This lock have to be released by rpc_put_sb_net() when all operations
1222  * will be completed.
1223  */
1224 struct super_block *rpc_get_sb_net(const struct net *net)
1225 {
1226         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1227
1228         mutex_lock(&sn->pipefs_sb_lock);
1229         if (sn->pipefs_sb)
1230                 return sn->pipefs_sb;
1231         mutex_unlock(&sn->pipefs_sb_lock);
1232         return NULL;
1233 }
1234 EXPORT_SYMBOL_GPL(rpc_get_sb_net);
1235
1236 void rpc_put_sb_net(const struct net *net)
1237 {
1238         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1239
1240         WARN_ON(sn->pipefs_sb == NULL);
1241         mutex_unlock(&sn->pipefs_sb_lock);
1242 }
1243 EXPORT_SYMBOL_GPL(rpc_put_sb_net);
1244
1245 static const struct rpc_filelist gssd_dummy_clnt_dir[] = {
1246         [0] = {
1247                 .name = "clntXX",
1248                 .mode = S_IFDIR | 0555,
1249         },
1250 };
1251
1252 static ssize_t
1253 dummy_downcall(struct file *filp, const char __user *src, size_t len)
1254 {
1255         return -EINVAL;
1256 }
1257
1258 static const struct rpc_pipe_ops gssd_dummy_pipe_ops = {
1259         .upcall         = rpc_pipe_generic_upcall,
1260         .downcall       = dummy_downcall,
1261 };
1262
1263 /*
1264  * Here we present a bogus "info" file to keep rpc.gssd happy. We don't expect
1265  * that it will ever use this info to handle an upcall, but rpc.gssd expects
1266  * that this file will be there and have a certain format.
1267  */
1268 static int
1269 rpc_dummy_info_show(struct seq_file *m, void *v)
1270 {
1271         seq_printf(m, "RPC server: %s\n", utsname()->nodename);
1272         seq_printf(m, "service: foo (1) version 0\n");
1273         seq_printf(m, "address: 127.0.0.1\n");
1274         seq_printf(m, "protocol: tcp\n");
1275         seq_printf(m, "port: 0\n");
1276         return 0;
1277 }
1278 DEFINE_SHOW_ATTRIBUTE(rpc_dummy_info);
1279
1280 static const struct rpc_filelist gssd_dummy_info_file[] = {
1281         [0] = {
1282                 .name = "info",
1283                 .i_fop = &rpc_dummy_info_fops,
1284                 .mode = S_IFREG | 0400,
1285         },
1286 };
1287
1288 /**
1289  * rpc_gssd_dummy_populate - create a dummy gssd pipe
1290  * @root:       root of the rpc_pipefs filesystem
1291  * @pipe_data:  pipe data created when netns is initialized
1292  *
1293  * Create a dummy set of directories and a pipe that gssd can hold open to
1294  * indicate that it is up and running.
1295  */
1296 static struct dentry *
1297 rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data)
1298 {
1299         int ret = 0;
1300         struct dentry *gssd_dentry;
1301         struct dentry *clnt_dentry = NULL;
1302         struct dentry *pipe_dentry = NULL;
1303         struct qstr q = QSTR_INIT(files[RPCAUTH_gssd].name,
1304                                   strlen(files[RPCAUTH_gssd].name));
1305
1306         /* We should never get this far if "gssd" doesn't exist */
1307         gssd_dentry = d_hash_and_lookup(root, &q);
1308         if (!gssd_dentry)
1309                 return ERR_PTR(-ENOENT);
1310
1311         ret = rpc_populate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1, NULL);
1312         if (ret) {
1313                 pipe_dentry = ERR_PTR(ret);
1314                 goto out;
1315         }
1316
1317         q.name = gssd_dummy_clnt_dir[0].name;
1318         q.len = strlen(gssd_dummy_clnt_dir[0].name);
1319         clnt_dentry = d_hash_and_lookup(gssd_dentry, &q);
1320         if (!clnt_dentry) {
1321                 pipe_dentry = ERR_PTR(-ENOENT);
1322                 goto out;
1323         }
1324
1325         ret = rpc_populate(clnt_dentry, gssd_dummy_info_file, 0, 1, NULL);
1326         if (ret) {
1327                 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1328                 pipe_dentry = ERR_PTR(ret);
1329                 goto out;
1330         }
1331
1332         pipe_dentry = rpc_mkpipe_dentry(clnt_dentry, "gssd", NULL, pipe_data);
1333         if (IS_ERR(pipe_dentry)) {
1334                 __rpc_depopulate(clnt_dentry, gssd_dummy_info_file, 0, 1);
1335                 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1336         }
1337 out:
1338         dput(clnt_dentry);
1339         dput(gssd_dentry);
1340         return pipe_dentry;
1341 }
1342
1343 static void
1344 rpc_gssd_dummy_depopulate(struct dentry *pipe_dentry)
1345 {
1346         struct dentry *clnt_dir = pipe_dentry->d_parent;
1347         struct dentry *gssd_dir = clnt_dir->d_parent;
1348
1349         dget(pipe_dentry);
1350         __rpc_rmpipe(d_inode(clnt_dir), pipe_dentry);
1351         __rpc_depopulate(clnt_dir, gssd_dummy_info_file, 0, 1);
1352         __rpc_depopulate(gssd_dir, gssd_dummy_clnt_dir, 0, 1);
1353         dput(pipe_dentry);
1354 }
1355
1356 static int
1357 rpc_fill_super(struct super_block *sb, void *data, int silent)
1358 {
1359         struct inode *inode;
1360         struct dentry *root, *gssd_dentry;
1361         struct net *net = get_net(sb->s_fs_info);
1362         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1363         int err;
1364
1365         sb->s_blocksize = PAGE_SIZE;
1366         sb->s_blocksize_bits = PAGE_SHIFT;
1367         sb->s_magic = RPCAUTH_GSSMAGIC;
1368         sb->s_op = &s_ops;
1369         sb->s_d_op = &simple_dentry_operations;
1370         sb->s_time_gran = 1;
1371
1372         inode = rpc_get_inode(sb, S_IFDIR | 0555);
1373         sb->s_root = root = d_make_root(inode);
1374         if (!root)
1375                 return -ENOMEM;
1376         if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
1377                 return -ENOMEM;
1378
1379         gssd_dentry = rpc_gssd_dummy_populate(root, sn->gssd_dummy);
1380         if (IS_ERR(gssd_dentry)) {
1381                 __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1382                 return PTR_ERR(gssd_dentry);
1383         }
1384
1385         dprintk("RPC:       sending pipefs MOUNT notification for net %x%s\n",
1386                 net->ns.inum, NET_NAME(net));
1387         mutex_lock(&sn->pipefs_sb_lock);
1388         sn->pipefs_sb = sb;
1389         err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1390                                            RPC_PIPEFS_MOUNT,
1391                                            sb);
1392         if (err)
1393                 goto err_depopulate;
1394         mutex_unlock(&sn->pipefs_sb_lock);
1395         return 0;
1396
1397 err_depopulate:
1398         rpc_gssd_dummy_depopulate(gssd_dentry);
1399         blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1400                                            RPC_PIPEFS_UMOUNT,
1401                                            sb);
1402         sn->pipefs_sb = NULL;
1403         __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1404         mutex_unlock(&sn->pipefs_sb_lock);
1405         return err;
1406 }
1407
1408 bool
1409 gssd_running(struct net *net)
1410 {
1411         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1412         struct rpc_pipe *pipe = sn->gssd_dummy;
1413
1414         return pipe->nreaders || pipe->nwriters;
1415 }
1416 EXPORT_SYMBOL_GPL(gssd_running);
1417
1418 static struct dentry *
1419 rpc_mount(struct file_system_type *fs_type,
1420                 int flags, const char *dev_name, void *data)
1421 {
1422         struct net *net = current->nsproxy->net_ns;
1423         return mount_ns(fs_type, flags, data, net, net->user_ns, rpc_fill_super);
1424 }
1425
1426 static void rpc_kill_sb(struct super_block *sb)
1427 {
1428         struct net *net = sb->s_fs_info;
1429         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1430
1431         mutex_lock(&sn->pipefs_sb_lock);
1432         if (sn->pipefs_sb != sb) {
1433                 mutex_unlock(&sn->pipefs_sb_lock);
1434                 goto out;
1435         }
1436         sn->pipefs_sb = NULL;
1437         dprintk("RPC:       sending pipefs UMOUNT notification for net %x%s\n",
1438                 net->ns.inum, NET_NAME(net));
1439         blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1440                                            RPC_PIPEFS_UMOUNT,
1441                                            sb);
1442         mutex_unlock(&sn->pipefs_sb_lock);
1443 out:
1444         kill_litter_super(sb);
1445         put_net(net);
1446 }
1447
1448 static struct file_system_type rpc_pipe_fs_type = {
1449         .owner          = THIS_MODULE,
1450         .name           = "rpc_pipefs",
1451         .mount          = rpc_mount,
1452         .kill_sb        = rpc_kill_sb,
1453 };
1454 MODULE_ALIAS_FS("rpc_pipefs");
1455 MODULE_ALIAS("rpc_pipefs");
1456
1457 static void
1458 init_once(void *foo)
1459 {
1460         struct rpc_inode *rpci = (struct rpc_inode *) foo;
1461
1462         inode_init_once(&rpci->vfs_inode);
1463         rpci->private = NULL;
1464         rpci->pipe = NULL;
1465         init_waitqueue_head(&rpci->waitq);
1466 }
1467
1468 int register_rpc_pipefs(void)
1469 {
1470         int err;
1471
1472         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1473                                 sizeof(struct rpc_inode),
1474                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1475                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1476                                 init_once);
1477         if (!rpc_inode_cachep)
1478                 return -ENOMEM;
1479         err = rpc_clients_notifier_register();
1480         if (err)
1481                 goto err_notifier;
1482         err = register_filesystem(&rpc_pipe_fs_type);
1483         if (err)
1484                 goto err_register;
1485         return 0;
1486
1487 err_register:
1488         rpc_clients_notifier_unregister();
1489 err_notifier:
1490         kmem_cache_destroy(rpc_inode_cachep);
1491         return err;
1492 }
1493
1494 void unregister_rpc_pipefs(void)
1495 {
1496         rpc_clients_notifier_unregister();
1497         kmem_cache_destroy(rpc_inode_cachep);
1498         unregister_filesystem(&rpc_pipe_fs_type);
1499 }