Merge branch 'for-3.4' of git://linux-nfs.org/~bfields/linux
[linux-3.10.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
21 #include <asm/ioctls.h>
22 #include <linux/poll.h>
23 #include <linux/wait.h>
24 #include <linux/seq_file.h>
25
26 #include <linux/sunrpc/clnt.h>
27 #include <linux/workqueue.h>
28 #include <linux/sunrpc/rpc_pipe_fs.h>
29 #include <linux/sunrpc/cache.h>
30 #include <linux/nsproxy.h>
31 #include <linux/notifier.h>
32
33 #include "netns.h"
34 #include "sunrpc.h"
35
36 #define RPCDBG_FACILITY RPCDBG_DEBUG
37
38 #define NET_NAME(net)   ((net == &init_net) ? " (init_net)" : "")
39
40 static struct file_system_type rpc_pipe_fs_type;
41
42
43 static struct kmem_cache *rpc_inode_cachep __read_mostly;
44
45 #define RPC_UPCALL_TIMEOUT (30*HZ)
46
47 static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
48
49 int rpc_pipefs_notifier_register(struct notifier_block *nb)
50 {
51         return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb);
52 }
53 EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
54
55 void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
56 {
57         blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
58 }
59 EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
60
61 static void rpc_purge_list(wait_queue_head_t *waitq, struct list_head *head,
62                 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
63 {
64         struct rpc_pipe_msg *msg;
65
66         if (list_empty(head))
67                 return;
68         do {
69                 msg = list_entry(head->next, struct rpc_pipe_msg, list);
70                 list_del_init(&msg->list);
71                 msg->errno = err;
72                 destroy_msg(msg);
73         } while (!list_empty(head));
74         wake_up(waitq);
75 }
76
77 static void
78 rpc_timeout_upcall_queue(struct work_struct *work)
79 {
80         LIST_HEAD(free_list);
81         struct rpc_pipe *pipe =
82                 container_of(work, struct rpc_pipe, queue_timeout.work);
83         void (*destroy_msg)(struct rpc_pipe_msg *);
84         struct dentry *dentry;
85
86         spin_lock(&pipe->lock);
87         destroy_msg = pipe->ops->destroy_msg;
88         if (pipe->nreaders == 0) {
89                 list_splice_init(&pipe->pipe, &free_list);
90                 pipe->pipelen = 0;
91         }
92         dentry = dget(pipe->dentry);
93         spin_unlock(&pipe->lock);
94         if (dentry) {
95                 rpc_purge_list(&RPC_I(dentry->d_inode)->waitq,
96                                &free_list, destroy_msg, -ETIMEDOUT);
97                 dput(dentry);
98         }
99 }
100
101 ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
102                                 char __user *dst, size_t buflen)
103 {
104         char *data = (char *)msg->data + msg->copied;
105         size_t mlen = min(msg->len - msg->copied, buflen);
106         unsigned long left;
107
108         left = copy_to_user(dst, data, mlen);
109         if (left == mlen) {
110                 msg->errno = -EFAULT;
111                 return -EFAULT;
112         }
113
114         mlen -= left;
115         msg->copied += mlen;
116         msg->errno = 0;
117         return mlen;
118 }
119 EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
120
121 /**
122  * rpc_queue_upcall - queue an upcall message to userspace
123  * @inode: inode of upcall pipe on which to queue given message
124  * @msg: message to queue
125  *
126  * Call with an @inode created by rpc_mkpipe() to queue an upcall.
127  * A userspace process may then later read the upcall by performing a
128  * read on an open file for this inode.  It is up to the caller to
129  * initialize the fields of @msg (other than @msg->list) appropriately.
130  */
131 int
132 rpc_queue_upcall(struct rpc_pipe *pipe, struct rpc_pipe_msg *msg)
133 {
134         int res = -EPIPE;
135         struct dentry *dentry;
136
137         spin_lock(&pipe->lock);
138         if (pipe->nreaders) {
139                 list_add_tail(&msg->list, &pipe->pipe);
140                 pipe->pipelen += msg->len;
141                 res = 0;
142         } else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
143                 if (list_empty(&pipe->pipe))
144                         queue_delayed_work(rpciod_workqueue,
145                                         &pipe->queue_timeout,
146                                         RPC_UPCALL_TIMEOUT);
147                 list_add_tail(&msg->list, &pipe->pipe);
148                 pipe->pipelen += msg->len;
149                 res = 0;
150         }
151         dentry = dget(pipe->dentry);
152         spin_unlock(&pipe->lock);
153         if (dentry) {
154                 wake_up(&RPC_I(dentry->d_inode)->waitq);
155                 dput(dentry);
156         }
157         return res;
158 }
159 EXPORT_SYMBOL_GPL(rpc_queue_upcall);
160
161 static inline void
162 rpc_inode_setowner(struct inode *inode, void *private)
163 {
164         RPC_I(inode)->private = private;
165 }
166
167 static void
168 rpc_close_pipes(struct inode *inode)
169 {
170         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
171         int need_release;
172         LIST_HEAD(free_list);
173
174         mutex_lock(&inode->i_mutex);
175         spin_lock(&pipe->lock);
176         need_release = pipe->nreaders != 0 || pipe->nwriters != 0;
177         pipe->nreaders = 0;
178         list_splice_init(&pipe->in_upcall, &free_list);
179         list_splice_init(&pipe->pipe, &free_list);
180         pipe->pipelen = 0;
181         pipe->dentry = NULL;
182         spin_unlock(&pipe->lock);
183         rpc_purge_list(&RPC_I(inode)->waitq, &free_list, pipe->ops->destroy_msg, -EPIPE);
184         pipe->nwriters = 0;
185         if (need_release && pipe->ops->release_pipe)
186                 pipe->ops->release_pipe(inode);
187         cancel_delayed_work_sync(&pipe->queue_timeout);
188         rpc_inode_setowner(inode, NULL);
189         RPC_I(inode)->pipe = NULL;
190         mutex_unlock(&inode->i_mutex);
191 }
192
193 static struct inode *
194 rpc_alloc_inode(struct super_block *sb)
195 {
196         struct rpc_inode *rpci;
197         rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
198         if (!rpci)
199                 return NULL;
200         return &rpci->vfs_inode;
201 }
202
203 static void
204 rpc_i_callback(struct rcu_head *head)
205 {
206         struct inode *inode = container_of(head, struct inode, i_rcu);
207         kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
208 }
209
210 static void
211 rpc_destroy_inode(struct inode *inode)
212 {
213         call_rcu(&inode->i_rcu, rpc_i_callback);
214 }
215
216 static int
217 rpc_pipe_open(struct inode *inode, struct file *filp)
218 {
219         struct rpc_pipe *pipe;
220         int first_open;
221         int res = -ENXIO;
222
223         mutex_lock(&inode->i_mutex);
224         pipe = RPC_I(inode)->pipe;
225         if (pipe == NULL)
226                 goto out;
227         first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
228         if (first_open && pipe->ops->open_pipe) {
229                 res = pipe->ops->open_pipe(inode);
230                 if (res)
231                         goto out;
232         }
233         if (filp->f_mode & FMODE_READ)
234                 pipe->nreaders++;
235         if (filp->f_mode & FMODE_WRITE)
236                 pipe->nwriters++;
237         res = 0;
238 out:
239         mutex_unlock(&inode->i_mutex);
240         return res;
241 }
242
243 static int
244 rpc_pipe_release(struct inode *inode, struct file *filp)
245 {
246         struct rpc_pipe *pipe;
247         struct rpc_pipe_msg *msg;
248         int last_close;
249
250         mutex_lock(&inode->i_mutex);
251         pipe = RPC_I(inode)->pipe;
252         if (pipe == NULL)
253                 goto out;
254         msg = filp->private_data;
255         if (msg != NULL) {
256                 spin_lock(&pipe->lock);
257                 msg->errno = -EAGAIN;
258                 list_del_init(&msg->list);
259                 spin_unlock(&pipe->lock);
260                 pipe->ops->destroy_msg(msg);
261         }
262         if (filp->f_mode & FMODE_WRITE)
263                 pipe->nwriters --;
264         if (filp->f_mode & FMODE_READ) {
265                 pipe->nreaders --;
266                 if (pipe->nreaders == 0) {
267                         LIST_HEAD(free_list);
268                         spin_lock(&pipe->lock);
269                         list_splice_init(&pipe->pipe, &free_list);
270                         pipe->pipelen = 0;
271                         spin_unlock(&pipe->lock);
272                         rpc_purge_list(&RPC_I(inode)->waitq, &free_list,
273                                         pipe->ops->destroy_msg, -EAGAIN);
274                 }
275         }
276         last_close = pipe->nwriters == 0 && pipe->nreaders == 0;
277         if (last_close && pipe->ops->release_pipe)
278                 pipe->ops->release_pipe(inode);
279 out:
280         mutex_unlock(&inode->i_mutex);
281         return 0;
282 }
283
284 static ssize_t
285 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
286 {
287         struct inode *inode = filp->f_path.dentry->d_inode;
288         struct rpc_pipe *pipe;
289         struct rpc_pipe_msg *msg;
290         int res = 0;
291
292         mutex_lock(&inode->i_mutex);
293         pipe = RPC_I(inode)->pipe;
294         if (pipe == NULL) {
295                 res = -EPIPE;
296                 goto out_unlock;
297         }
298         msg = filp->private_data;
299         if (msg == NULL) {
300                 spin_lock(&pipe->lock);
301                 if (!list_empty(&pipe->pipe)) {
302                         msg = list_entry(pipe->pipe.next,
303                                         struct rpc_pipe_msg,
304                                         list);
305                         list_move(&msg->list, &pipe->in_upcall);
306                         pipe->pipelen -= msg->len;
307                         filp->private_data = msg;
308                         msg->copied = 0;
309                 }
310                 spin_unlock(&pipe->lock);
311                 if (msg == NULL)
312                         goto out_unlock;
313         }
314         /* NOTE: it is up to the callback to update msg->copied */
315         res = pipe->ops->upcall(filp, msg, buf, len);
316         if (res < 0 || msg->len == msg->copied) {
317                 filp->private_data = NULL;
318                 spin_lock(&pipe->lock);
319                 list_del_init(&msg->list);
320                 spin_unlock(&pipe->lock);
321                 pipe->ops->destroy_msg(msg);
322         }
323 out_unlock:
324         mutex_unlock(&inode->i_mutex);
325         return res;
326 }
327
328 static ssize_t
329 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
330 {
331         struct inode *inode = filp->f_path.dentry->d_inode;
332         int res;
333
334         mutex_lock(&inode->i_mutex);
335         res = -EPIPE;
336         if (RPC_I(inode)->pipe != NULL)
337                 res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len);
338         mutex_unlock(&inode->i_mutex);
339         return res;
340 }
341
342 static unsigned int
343 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
344 {
345         struct inode *inode = filp->f_path.dentry->d_inode;
346         struct rpc_inode *rpci = RPC_I(inode);
347         unsigned int mask = POLLOUT | POLLWRNORM;
348
349         poll_wait(filp, &rpci->waitq, wait);
350
351         mutex_lock(&inode->i_mutex);
352         if (rpci->pipe == NULL)
353                 mask |= POLLERR | POLLHUP;
354         else if (filp->private_data || !list_empty(&rpci->pipe->pipe))
355                 mask |= POLLIN | POLLRDNORM;
356         mutex_unlock(&inode->i_mutex);
357         return mask;
358 }
359
360 static long
361 rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
362 {
363         struct inode *inode = filp->f_path.dentry->d_inode;
364         struct rpc_pipe *pipe;
365         int len;
366
367         switch (cmd) {
368         case FIONREAD:
369                 mutex_lock(&inode->i_mutex);
370                 pipe = RPC_I(inode)->pipe;
371                 if (pipe == NULL) {
372                         mutex_unlock(&inode->i_mutex);
373                         return -EPIPE;
374                 }
375                 spin_lock(&pipe->lock);
376                 len = pipe->pipelen;
377                 if (filp->private_data) {
378                         struct rpc_pipe_msg *msg;
379                         msg = filp->private_data;
380                         len += msg->len - msg->copied;
381                 }
382                 spin_unlock(&pipe->lock);
383                 mutex_unlock(&inode->i_mutex);
384                 return put_user(len, (int __user *)arg);
385         default:
386                 return -EINVAL;
387         }
388 }
389
390 static const struct file_operations rpc_pipe_fops = {
391         .owner          = THIS_MODULE,
392         .llseek         = no_llseek,
393         .read           = rpc_pipe_read,
394         .write          = rpc_pipe_write,
395         .poll           = rpc_pipe_poll,
396         .unlocked_ioctl = rpc_pipe_ioctl,
397         .open           = rpc_pipe_open,
398         .release        = rpc_pipe_release,
399 };
400
401 static int
402 rpc_show_info(struct seq_file *m, void *v)
403 {
404         struct rpc_clnt *clnt = m->private;
405
406         rcu_read_lock();
407         seq_printf(m, "RPC server: %s\n",
408                         rcu_dereference(clnt->cl_xprt)->servername);
409         seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
410                         clnt->cl_prog, clnt->cl_vers);
411         seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
412         seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
413         seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
414         rcu_read_unlock();
415         return 0;
416 }
417
418 static int
419 rpc_info_open(struct inode *inode, struct file *file)
420 {
421         struct rpc_clnt *clnt = NULL;
422         int ret = single_open(file, rpc_show_info, NULL);
423
424         if (!ret) {
425                 struct seq_file *m = file->private_data;
426
427                 spin_lock(&file->f_path.dentry->d_lock);
428                 if (!d_unhashed(file->f_path.dentry))
429                         clnt = RPC_I(inode)->private;
430                 if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) {
431                         spin_unlock(&file->f_path.dentry->d_lock);
432                         m->private = clnt;
433                 } else {
434                         spin_unlock(&file->f_path.dentry->d_lock);
435                         single_release(inode, file);
436                         ret = -EINVAL;
437                 }
438         }
439         return ret;
440 }
441
442 static int
443 rpc_info_release(struct inode *inode, struct file *file)
444 {
445         struct seq_file *m = file->private_data;
446         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
447
448         if (clnt)
449                 rpc_release_client(clnt);
450         return single_release(inode, file);
451 }
452
453 static const struct file_operations rpc_info_operations = {
454         .owner          = THIS_MODULE,
455         .open           = rpc_info_open,
456         .read           = seq_read,
457         .llseek         = seq_lseek,
458         .release        = rpc_info_release,
459 };
460
461
462 /*
463  * Description of fs contents.
464  */
465 struct rpc_filelist {
466         const char *name;
467         const struct file_operations *i_fop;
468         umode_t mode;
469 };
470
471 static int rpc_delete_dentry(const struct dentry *dentry)
472 {
473         return 1;
474 }
475
476 static const struct dentry_operations rpc_dentry_operations = {
477         .d_delete = rpc_delete_dentry,
478 };
479
480 static struct inode *
481 rpc_get_inode(struct super_block *sb, umode_t mode)
482 {
483         struct inode *inode = new_inode(sb);
484         if (!inode)
485                 return NULL;
486         inode->i_ino = get_next_ino();
487         inode->i_mode = mode;
488         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
489         switch (mode & S_IFMT) {
490         case S_IFDIR:
491                 inode->i_fop = &simple_dir_operations;
492                 inode->i_op = &simple_dir_inode_operations;
493                 inc_nlink(inode);
494         default:
495                 break;
496         }
497         return inode;
498 }
499
500 static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
501                                umode_t mode,
502                                const struct file_operations *i_fop,
503                                void *private)
504 {
505         struct inode *inode;
506
507         d_drop(dentry);
508         inode = rpc_get_inode(dir->i_sb, mode);
509         if (!inode)
510                 goto out_err;
511         inode->i_ino = iunique(dir->i_sb, 100);
512         if (i_fop)
513                 inode->i_fop = i_fop;
514         if (private)
515                 rpc_inode_setowner(inode, private);
516         d_add(dentry, inode);
517         return 0;
518 out_err:
519         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
520                         __FILE__, __func__, dentry->d_name.name);
521         dput(dentry);
522         return -ENOMEM;
523 }
524
525 static int __rpc_create(struct inode *dir, struct dentry *dentry,
526                         umode_t mode,
527                         const struct file_operations *i_fop,
528                         void *private)
529 {
530         int err;
531
532         err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
533         if (err)
534                 return err;
535         fsnotify_create(dir, dentry);
536         return 0;
537 }
538
539 static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
540                        umode_t mode,
541                        const struct file_operations *i_fop,
542                        void *private)
543 {
544         int err;
545
546         err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
547         if (err)
548                 return err;
549         inc_nlink(dir);
550         fsnotify_mkdir(dir, dentry);
551         return 0;
552 }
553
554 static void
555 init_pipe(struct rpc_pipe *pipe)
556 {
557         pipe->nreaders = 0;
558         pipe->nwriters = 0;
559         INIT_LIST_HEAD(&pipe->in_upcall);
560         INIT_LIST_HEAD(&pipe->in_downcall);
561         INIT_LIST_HEAD(&pipe->pipe);
562         pipe->pipelen = 0;
563         INIT_DELAYED_WORK(&pipe->queue_timeout,
564                             rpc_timeout_upcall_queue);
565         pipe->ops = NULL;
566         spin_lock_init(&pipe->lock);
567         pipe->dentry = NULL;
568 }
569
570 void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
571 {
572         kfree(pipe);
573 }
574 EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
575
576 struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
577 {
578         struct rpc_pipe *pipe;
579
580         pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
581         if (!pipe)
582                 return ERR_PTR(-ENOMEM);
583         init_pipe(pipe);
584         pipe->ops = ops;
585         pipe->flags = flags;
586         return pipe;
587 }
588 EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
589
590 static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
591                                umode_t mode,
592                                const struct file_operations *i_fop,
593                                void *private,
594                                struct rpc_pipe *pipe)
595 {
596         struct rpc_inode *rpci;
597         int err;
598
599         err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
600         if (err)
601                 return err;
602         rpci = RPC_I(dentry->d_inode);
603         rpci->private = private;
604         rpci->pipe = pipe;
605         fsnotify_create(dir, dentry);
606         return 0;
607 }
608
609 static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
610 {
611         int ret;
612
613         dget(dentry);
614         ret = simple_rmdir(dir, dentry);
615         d_delete(dentry);
616         dput(dentry);
617         return ret;
618 }
619
620 int rpc_rmdir(struct dentry *dentry)
621 {
622         struct dentry *parent;
623         struct inode *dir;
624         int error;
625
626         parent = dget_parent(dentry);
627         dir = parent->d_inode;
628         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
629         error = __rpc_rmdir(dir, dentry);
630         mutex_unlock(&dir->i_mutex);
631         dput(parent);
632         return error;
633 }
634 EXPORT_SYMBOL_GPL(rpc_rmdir);
635
636 static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
637 {
638         int ret;
639
640         dget(dentry);
641         ret = simple_unlink(dir, dentry);
642         d_delete(dentry);
643         dput(dentry);
644         return ret;
645 }
646
647 static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
648 {
649         struct inode *inode = dentry->d_inode;
650
651         rpc_close_pipes(inode);
652         return __rpc_unlink(dir, dentry);
653 }
654
655 static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
656                                           struct qstr *name)
657 {
658         struct dentry *dentry;
659
660         dentry = d_lookup(parent, name);
661         if (!dentry) {
662                 dentry = d_alloc(parent, name);
663                 if (!dentry)
664                         return ERR_PTR(-ENOMEM);
665         }
666         if (dentry->d_inode == NULL) {
667                 d_set_d_op(dentry, &rpc_dentry_operations);
668                 return dentry;
669         }
670         dput(dentry);
671         return ERR_PTR(-EEXIST);
672 }
673
674 /*
675  * FIXME: This probably has races.
676  */
677 static void __rpc_depopulate(struct dentry *parent,
678                              const struct rpc_filelist *files,
679                              int start, int eof)
680 {
681         struct inode *dir = parent->d_inode;
682         struct dentry *dentry;
683         struct qstr name;
684         int i;
685
686         for (i = start; i < eof; i++) {
687                 name.name = files[i].name;
688                 name.len = strlen(files[i].name);
689                 name.hash = full_name_hash(name.name, name.len);
690                 dentry = d_lookup(parent, &name);
691
692                 if (dentry == NULL)
693                         continue;
694                 if (dentry->d_inode == NULL)
695                         goto next;
696                 switch (dentry->d_inode->i_mode & S_IFMT) {
697                         default:
698                                 BUG();
699                         case S_IFREG:
700                                 __rpc_unlink(dir, dentry);
701                                 break;
702                         case S_IFDIR:
703                                 __rpc_rmdir(dir, dentry);
704                 }
705 next:
706                 dput(dentry);
707         }
708 }
709
710 static void rpc_depopulate(struct dentry *parent,
711                            const struct rpc_filelist *files,
712                            int start, int eof)
713 {
714         struct inode *dir = parent->d_inode;
715
716         mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
717         __rpc_depopulate(parent, files, start, eof);
718         mutex_unlock(&dir->i_mutex);
719 }
720
721 static int rpc_populate(struct dentry *parent,
722                         const struct rpc_filelist *files,
723                         int start, int eof,
724                         void *private)
725 {
726         struct inode *dir = parent->d_inode;
727         struct dentry *dentry;
728         int i, err;
729
730         mutex_lock(&dir->i_mutex);
731         for (i = start; i < eof; i++) {
732                 struct qstr q;
733
734                 q.name = files[i].name;
735                 q.len = strlen(files[i].name);
736                 q.hash = full_name_hash(q.name, q.len);
737                 dentry = __rpc_lookup_create_exclusive(parent, &q);
738                 err = PTR_ERR(dentry);
739                 if (IS_ERR(dentry))
740                         goto out_bad;
741                 switch (files[i].mode & S_IFMT) {
742                         default:
743                                 BUG();
744                         case S_IFREG:
745                                 err = __rpc_create(dir, dentry,
746                                                 files[i].mode,
747                                                 files[i].i_fop,
748                                                 private);
749                                 break;
750                         case S_IFDIR:
751                                 err = __rpc_mkdir(dir, dentry,
752                                                 files[i].mode,
753                                                 NULL,
754                                                 private);
755                 }
756                 if (err != 0)
757                         goto out_bad;
758         }
759         mutex_unlock(&dir->i_mutex);
760         return 0;
761 out_bad:
762         __rpc_depopulate(parent, files, start, eof);
763         mutex_unlock(&dir->i_mutex);
764         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
765                         __FILE__, __func__, parent->d_name.name);
766         return err;
767 }
768
769 static struct dentry *rpc_mkdir_populate(struct dentry *parent,
770                 struct qstr *name, umode_t mode, void *private,
771                 int (*populate)(struct dentry *, void *), void *args_populate)
772 {
773         struct dentry *dentry;
774         struct inode *dir = parent->d_inode;
775         int error;
776
777         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
778         dentry = __rpc_lookup_create_exclusive(parent, name);
779         if (IS_ERR(dentry))
780                 goto out;
781         error = __rpc_mkdir(dir, dentry, mode, NULL, private);
782         if (error != 0)
783                 goto out_err;
784         if (populate != NULL) {
785                 error = populate(dentry, args_populate);
786                 if (error)
787                         goto err_rmdir;
788         }
789 out:
790         mutex_unlock(&dir->i_mutex);
791         return dentry;
792 err_rmdir:
793         __rpc_rmdir(dir, dentry);
794 out_err:
795         dentry = ERR_PTR(error);
796         goto out;
797 }
798
799 static int rpc_rmdir_depopulate(struct dentry *dentry,
800                 void (*depopulate)(struct dentry *))
801 {
802         struct dentry *parent;
803         struct inode *dir;
804         int error;
805
806         parent = dget_parent(dentry);
807         dir = parent->d_inode;
808         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
809         if (depopulate != NULL)
810                 depopulate(dentry);
811         error = __rpc_rmdir(dir, dentry);
812         mutex_unlock(&dir->i_mutex);
813         dput(parent);
814         return error;
815 }
816
817 /**
818  * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
819  * @parent: dentry of directory to create new "pipe" in
820  * @name: name of pipe
821  * @private: private data to associate with the pipe, for the caller's use
822  * @ops: operations defining the behavior of the pipe: upcall, downcall,
823  *      release_pipe, open_pipe, and destroy_msg.
824  * @flags: rpc_pipe flags
825  *
826  * Data is made available for userspace to read by calls to
827  * rpc_queue_upcall().  The actual reads will result in calls to
828  * @ops->upcall, which will be called with the file pointer,
829  * message, and userspace buffer to copy to.
830  *
831  * Writes can come at any time, and do not necessarily have to be
832  * responses to upcalls.  They will result in calls to @msg->downcall.
833  *
834  * The @private argument passed here will be available to all these methods
835  * from the file pointer, via RPC_I(file->f_dentry->d_inode)->private.
836  */
837 struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
838                                  void *private, struct rpc_pipe *pipe)
839 {
840         struct dentry *dentry;
841         struct inode *dir = parent->d_inode;
842         umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR;
843         struct qstr q;
844         int err;
845
846         if (pipe->ops->upcall == NULL)
847                 umode &= ~S_IRUGO;
848         if (pipe->ops->downcall == NULL)
849                 umode &= ~S_IWUGO;
850
851         q.name = name;
852         q.len = strlen(name);
853         q.hash = full_name_hash(q.name, q.len),
854
855         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
856         dentry = __rpc_lookup_create_exclusive(parent, &q);
857         if (IS_ERR(dentry))
858                 goto out;
859         err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
860                                   private, pipe);
861         if (err)
862                 goto out_err;
863 out:
864         mutex_unlock(&dir->i_mutex);
865         return dentry;
866 out_err:
867         dentry = ERR_PTR(err);
868         printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
869                         __FILE__, __func__, parent->d_name.name, name,
870                         err);
871         goto out;
872 }
873 EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
874
875 /**
876  * rpc_unlink - remove a pipe
877  * @dentry: dentry for the pipe, as returned from rpc_mkpipe
878  *
879  * After this call, lookups will no longer find the pipe, and any
880  * attempts to read or write using preexisting opens of the pipe will
881  * return -EPIPE.
882  */
883 int
884 rpc_unlink(struct dentry *dentry)
885 {
886         struct dentry *parent;
887         struct inode *dir;
888         int error = 0;
889
890         parent = dget_parent(dentry);
891         dir = parent->d_inode;
892         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
893         error = __rpc_rmpipe(dir, dentry);
894         mutex_unlock(&dir->i_mutex);
895         dput(parent);
896         return error;
897 }
898 EXPORT_SYMBOL_GPL(rpc_unlink);
899
900 enum {
901         RPCAUTH_info,
902         RPCAUTH_EOF
903 };
904
905 static const struct rpc_filelist authfiles[] = {
906         [RPCAUTH_info] = {
907                 .name = "info",
908                 .i_fop = &rpc_info_operations,
909                 .mode = S_IFREG | S_IRUSR,
910         },
911 };
912
913 static int rpc_clntdir_populate(struct dentry *dentry, void *private)
914 {
915         return rpc_populate(dentry,
916                             authfiles, RPCAUTH_info, RPCAUTH_EOF,
917                             private);
918 }
919
920 static void rpc_clntdir_depopulate(struct dentry *dentry)
921 {
922         rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
923 }
924
925 /**
926  * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
927  * @dentry: dentry from the rpc_pipefs root to the new directory
928  * @name: &struct qstr for the name
929  * @rpc_client: rpc client to associate with this directory
930  *
931  * This creates a directory at the given @path associated with
932  * @rpc_clnt, which will contain a file named "info" with some basic
933  * information about the client, together with any "pipes" that may
934  * later be created using rpc_mkpipe().
935  */
936 struct dentry *rpc_create_client_dir(struct dentry *dentry,
937                                    struct qstr *name,
938                                    struct rpc_clnt *rpc_client)
939 {
940         return rpc_mkdir_populate(dentry, name, S_IRUGO | S_IXUGO, NULL,
941                         rpc_clntdir_populate, rpc_client);
942 }
943
944 /**
945  * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
946  * @clnt: rpc client
947  */
948 int rpc_remove_client_dir(struct dentry *dentry)
949 {
950         return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
951 }
952
953 static const struct rpc_filelist cache_pipefs_files[3] = {
954         [0] = {
955                 .name = "channel",
956                 .i_fop = &cache_file_operations_pipefs,
957                 .mode = S_IFREG|S_IRUSR|S_IWUSR,
958         },
959         [1] = {
960                 .name = "content",
961                 .i_fop = &content_file_operations_pipefs,
962                 .mode = S_IFREG|S_IRUSR,
963         },
964         [2] = {
965                 .name = "flush",
966                 .i_fop = &cache_flush_operations_pipefs,
967                 .mode = S_IFREG|S_IRUSR|S_IWUSR,
968         },
969 };
970
971 static int rpc_cachedir_populate(struct dentry *dentry, void *private)
972 {
973         return rpc_populate(dentry,
974                             cache_pipefs_files, 0, 3,
975                             private);
976 }
977
978 static void rpc_cachedir_depopulate(struct dentry *dentry)
979 {
980         rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
981 }
982
983 struct dentry *rpc_create_cache_dir(struct dentry *parent, struct qstr *name,
984                                     umode_t umode, struct cache_detail *cd)
985 {
986         return rpc_mkdir_populate(parent, name, umode, NULL,
987                         rpc_cachedir_populate, cd);
988 }
989
990 void rpc_remove_cache_dir(struct dentry *dentry)
991 {
992         rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
993 }
994
995 /*
996  * populate the filesystem
997  */
998 static const struct super_operations s_ops = {
999         .alloc_inode    = rpc_alloc_inode,
1000         .destroy_inode  = rpc_destroy_inode,
1001         .statfs         = simple_statfs,
1002 };
1003
1004 #define RPCAUTH_GSSMAGIC 0x67596969
1005
1006 /*
1007  * We have a single directory with 1 node in it.
1008  */
1009 enum {
1010         RPCAUTH_lockd,
1011         RPCAUTH_mount,
1012         RPCAUTH_nfs,
1013         RPCAUTH_portmap,
1014         RPCAUTH_statd,
1015         RPCAUTH_nfsd4_cb,
1016         RPCAUTH_cache,
1017         RPCAUTH_nfsd,
1018         RPCAUTH_RootEOF
1019 };
1020
1021 static const struct rpc_filelist files[] = {
1022         [RPCAUTH_lockd] = {
1023                 .name = "lockd",
1024                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1025         },
1026         [RPCAUTH_mount] = {
1027                 .name = "mount",
1028                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1029         },
1030         [RPCAUTH_nfs] = {
1031                 .name = "nfs",
1032                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1033         },
1034         [RPCAUTH_portmap] = {
1035                 .name = "portmap",
1036                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1037         },
1038         [RPCAUTH_statd] = {
1039                 .name = "statd",
1040                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1041         },
1042         [RPCAUTH_nfsd4_cb] = {
1043                 .name = "nfsd4_cb",
1044                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1045         },
1046         [RPCAUTH_cache] = {
1047                 .name = "cache",
1048                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1049         },
1050         [RPCAUTH_nfsd] = {
1051                 .name = "nfsd",
1052                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1053         },
1054 };
1055
1056 /*
1057  * This call can be used only in RPC pipefs mount notification hooks.
1058  */
1059 struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
1060                                const unsigned char *dir_name)
1061 {
1062         struct qstr dir = {
1063                 .name = dir_name,
1064                 .len = strlen(dir_name),
1065                 .hash = full_name_hash(dir_name, strlen(dir_name)),
1066         };
1067
1068         return d_lookup(sb->s_root, &dir);
1069 }
1070 EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
1071
1072 void rpc_pipefs_init_net(struct net *net)
1073 {
1074         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1075
1076         mutex_init(&sn->pipefs_sb_lock);
1077 }
1078
1079 /*
1080  * This call will be used for per network namespace operations calls.
1081  * Note: Function will be returned with pipefs_sb_lock taken if superblock was
1082  * found. This lock have to be released by rpc_put_sb_net() when all operations
1083  * will be completed.
1084  */
1085 struct super_block *rpc_get_sb_net(const struct net *net)
1086 {
1087         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1088
1089         mutex_lock(&sn->pipefs_sb_lock);
1090         if (sn->pipefs_sb)
1091                 return sn->pipefs_sb;
1092         mutex_unlock(&sn->pipefs_sb_lock);
1093         return NULL;
1094 }
1095 EXPORT_SYMBOL_GPL(rpc_get_sb_net);
1096
1097 void rpc_put_sb_net(const struct net *net)
1098 {
1099         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1100
1101         BUG_ON(sn->pipefs_sb == NULL);
1102         mutex_unlock(&sn->pipefs_sb_lock);
1103 }
1104 EXPORT_SYMBOL_GPL(rpc_put_sb_net);
1105
1106 static int
1107 rpc_fill_super(struct super_block *sb, void *data, int silent)
1108 {
1109         struct inode *inode;
1110         struct dentry *root;
1111         struct net *net = data;
1112         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1113         int err;
1114
1115         sb->s_blocksize = PAGE_CACHE_SIZE;
1116         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1117         sb->s_magic = RPCAUTH_GSSMAGIC;
1118         sb->s_op = &s_ops;
1119         sb->s_time_gran = 1;
1120
1121         inode = rpc_get_inode(sb, S_IFDIR | 0755);
1122         sb->s_root = root = d_make_root(inode);
1123         if (!root)
1124                 return -ENOMEM;
1125         if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
1126                 return -ENOMEM;
1127         dprintk("RPC:   sending pipefs MOUNT notification for net %p%s\n", net,
1128                                                                 NET_NAME(net));
1129         err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1130                                            RPC_PIPEFS_MOUNT,
1131                                            sb);
1132         if (err)
1133                 goto err_depopulate;
1134         sb->s_fs_info = get_net(net);
1135         sn->pipefs_sb = sb;
1136         return 0;
1137
1138 err_depopulate:
1139         blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1140                                            RPC_PIPEFS_UMOUNT,
1141                                            sb);
1142         __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1143         return err;
1144 }
1145
1146 static struct dentry *
1147 rpc_mount(struct file_system_type *fs_type,
1148                 int flags, const char *dev_name, void *data)
1149 {
1150         return mount_ns(fs_type, flags, current->nsproxy->net_ns, rpc_fill_super);
1151 }
1152
1153 static void rpc_kill_sb(struct super_block *sb)
1154 {
1155         struct net *net = sb->s_fs_info;
1156         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1157
1158         mutex_lock(&sn->pipefs_sb_lock);
1159         sn->pipefs_sb = NULL;
1160         mutex_unlock(&sn->pipefs_sb_lock);
1161         put_net(net);
1162         dprintk("RPC:   sending pipefs UMOUNT notification for net %p%s\n", net,
1163                                                                 NET_NAME(net));
1164         blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1165                                            RPC_PIPEFS_UMOUNT,
1166                                            sb);
1167         kill_litter_super(sb);
1168 }
1169
1170 static struct file_system_type rpc_pipe_fs_type = {
1171         .owner          = THIS_MODULE,
1172         .name           = "rpc_pipefs",
1173         .mount          = rpc_mount,
1174         .kill_sb        = rpc_kill_sb,
1175 };
1176
1177 static void
1178 init_once(void *foo)
1179 {
1180         struct rpc_inode *rpci = (struct rpc_inode *) foo;
1181
1182         inode_init_once(&rpci->vfs_inode);
1183         rpci->private = NULL;
1184         rpci->pipe = NULL;
1185         init_waitqueue_head(&rpci->waitq);
1186 }
1187
1188 int register_rpc_pipefs(void)
1189 {
1190         int err;
1191
1192         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1193                                 sizeof(struct rpc_inode),
1194                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1195                                                 SLAB_MEM_SPREAD),
1196                                 init_once);
1197         if (!rpc_inode_cachep)
1198                 return -ENOMEM;
1199         err = rpc_clients_notifier_register();
1200         if (err)
1201                 goto err_notifier;
1202         err = register_filesystem(&rpc_pipe_fs_type);
1203         if (err)
1204                 goto err_register;
1205         return 0;
1206
1207 err_register:
1208         rpc_clients_notifier_unregister();
1209 err_notifier:
1210         kmem_cache_destroy(rpc_inode_cachep);
1211         return err;
1212 }
1213
1214 void unregister_rpc_pipefs(void)
1215 {
1216         rpc_clients_notifier_unregister();
1217         kmem_cache_destroy(rpc_inode_cachep);
1218         unregister_filesystem(&rpc_pipe_fs_type);
1219 }
1220
1221 /* Make 'mount -t rpc_pipefs ...' autoload this module. */
1222 MODULE_ALIAS("rpc_pipefs");