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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux-2.6.git] / net / sunrpc / rpc_pipe.c
blob406859cc68aa90073ef237e91e0aa67116adcf33
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
75 if (waitq)
76 wake_up(waitq);
77 }
78
79 static void
80 rpc_timeout_upcall_queue(struct work_struct *work)
81 {
82 LIST_HEAD(free_list);
83 struct rpc_pipe *pipe =
84 container_of(work, struct rpc_pipe, queue_timeout.work);
85 void (*destroy_msg)(struct rpc_pipe_msg *);
86 struct dentry *dentry;
87
88 spin_lock(&pipe->lock);
89 destroy_msg = pipe->ops->destroy_msg;
90 if (pipe->nreaders == 0) {
91 list_splice_init(&pipe->pipe, &free_list);
92 pipe->pipelen = 0;
93 }
94 dentry = dget(pipe->dentry);
95 spin_unlock(&pipe->lock);
96 rpc_purge_list(dentry ? &RPC_I(dentry->d_inode)->waitq : NULL,
97 &free_list, destroy_msg, -ETIMEDOUT);
98 dput(dentry);
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 * @pipe: 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 net *net = inode->i_sb->s_fs_info;
220 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
221 struct rpc_pipe *pipe;
222 int first_open;
223 int res = -ENXIO;
224
225 mutex_lock(&inode->i_mutex);
226 sn->gssd_running = 1;
227 pipe = RPC_I(inode)->pipe;
228 if (pipe == NULL)
229 goto out;
230 first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
231 if (first_open && pipe->ops->open_pipe) {
232 res = pipe->ops->open_pipe(inode);
233 if (res)
234 goto out;
235 }
236 if (filp->f_mode & FMODE_READ)
237 pipe->nreaders++;
238 if (filp->f_mode & FMODE_WRITE)
239 pipe->nwriters++;
240 res = 0;
241 out:
242 mutex_unlock(&inode->i_mutex);
243 return res;
244 }
245
246 static int
247 rpc_pipe_release(struct inode *inode, struct file *filp)
248 {
249 struct rpc_pipe *pipe;
250 struct rpc_pipe_msg *msg;
251 int last_close;
252
253 mutex_lock(&inode->i_mutex);
254 pipe = RPC_I(inode)->pipe;
255 if (pipe == NULL)
256 goto out;
257 msg = filp->private_data;
258 if (msg != NULL) {
259 spin_lock(&pipe->lock);
260 msg->errno = -EAGAIN;
261 list_del_init(&msg->list);
262 spin_unlock(&pipe->lock);
263 pipe->ops->destroy_msg(msg);
264 }
265 if (filp->f_mode & FMODE_WRITE)
266 pipe->nwriters --;
267 if (filp->f_mode & FMODE_READ) {
268 pipe->nreaders --;
269 if (pipe->nreaders == 0) {
270 LIST_HEAD(free_list);
271 spin_lock(&pipe->lock);
272 list_splice_init(&pipe->pipe, &free_list);
273 pipe->pipelen = 0;
274 spin_unlock(&pipe->lock);
275 rpc_purge_list(&RPC_I(inode)->waitq, &free_list,
276 pipe->ops->destroy_msg, -EAGAIN);
277 }
278 }
279 last_close = pipe->nwriters == 0 && pipe->nreaders == 0;
280 if (last_close && pipe->ops->release_pipe)
281 pipe->ops->release_pipe(inode);
282 out:
283 mutex_unlock(&inode->i_mutex);
284 return 0;
285 }
286
287 static ssize_t
288 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
289 {
290 struct inode *inode = file_inode(filp);
291 struct rpc_pipe *pipe;
292 struct rpc_pipe_msg *msg;
293 int res = 0;
294
295 mutex_lock(&inode->i_mutex);
296 pipe = RPC_I(inode)->pipe;
297 if (pipe == NULL) {
298 res = -EPIPE;
299 goto out_unlock;
300 }
301 msg = filp->private_data;
302 if (msg == NULL) {
303 spin_lock(&pipe->lock);
304 if (!list_empty(&pipe->pipe)) {
305 msg = list_entry(pipe->pipe.next,
306 struct rpc_pipe_msg,
307 list);
308 list_move(&msg->list, &pipe->in_upcall);
309 pipe->pipelen -= msg->len;
310 filp->private_data = msg;
311 msg->copied = 0;
312 }
313 spin_unlock(&pipe->lock);
314 if (msg == NULL)
315 goto out_unlock;
316 }
317 /* NOTE: it is up to the callback to update msg->copied */
318 res = pipe->ops->upcall(filp, msg, buf, len);
319 if (res < 0 || msg->len == msg->copied) {
320 filp->private_data = NULL;
321 spin_lock(&pipe->lock);
322 list_del_init(&msg->list);
323 spin_unlock(&pipe->lock);
324 pipe->ops->destroy_msg(msg);
325 }
326 out_unlock:
327 mutex_unlock(&inode->i_mutex);
328 return res;
329 }
330
331 static ssize_t
332 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
333 {
334 struct inode *inode = file_inode(filp);
335 int res;
336
337 mutex_lock(&inode->i_mutex);
338 res = -EPIPE;
339 if (RPC_I(inode)->pipe != NULL)
340 res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len);
341 mutex_unlock(&inode->i_mutex);
342 return res;
343 }
344
345 static unsigned int
346 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
347 {
348 struct inode *inode = file_inode(filp);
349 struct rpc_inode *rpci = RPC_I(inode);
350 unsigned int mask = POLLOUT | POLLWRNORM;
351
352 poll_wait(filp, &rpci->waitq, wait);
353
354 mutex_lock(&inode->i_mutex);
355 if (rpci->pipe == NULL)
356 mask |= POLLERR | POLLHUP;
357 else if (filp->private_data || !list_empty(&rpci->pipe->pipe))
358 mask |= POLLIN | POLLRDNORM;
359 mutex_unlock(&inode->i_mutex);
360 return mask;
361 }
362
363 static long
364 rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
365 {
366 struct inode *inode = file_inode(filp);
367 struct rpc_pipe *pipe;
368 int len;
369
370 switch (cmd) {
371 case FIONREAD:
372 mutex_lock(&inode->i_mutex);
373 pipe = RPC_I(inode)->pipe;
374 if (pipe == NULL) {
375 mutex_unlock(&inode->i_mutex);
376 return -EPIPE;
377 }
378 spin_lock(&pipe->lock);
379 len = pipe->pipelen;
380 if (filp->private_data) {
381 struct rpc_pipe_msg *msg;
382 msg = filp->private_data;
383 len += msg->len - msg->copied;
384 }
385 spin_unlock(&pipe->lock);
386 mutex_unlock(&inode->i_mutex);
387 return put_user(len, (int __user *)arg);
388 default:
389 return -EINVAL;
390 }
391 }
392
393 static const struct file_operations rpc_pipe_fops = {
394 .owner = THIS_MODULE,
395 .llseek = no_llseek,
396 .read = rpc_pipe_read,
397 .write = rpc_pipe_write,
398 .poll = rpc_pipe_poll,
399 .unlocked_ioctl = rpc_pipe_ioctl,
400 .open = rpc_pipe_open,
401 .release = rpc_pipe_release,
402 };
403
404 static int
405 rpc_show_info(struct seq_file *m, void *v)
406 {
407 struct rpc_clnt *clnt = m->private;
408
409 rcu_read_lock();
410 seq_printf(m, "RPC server: %s\n",
411 rcu_dereference(clnt->cl_xprt)->servername);
412 seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
413 clnt->cl_prog, clnt->cl_vers);
414 seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
415 seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
416 seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
417 rcu_read_unlock();
418 return 0;
419 }
420
421 static int
422 rpc_info_open(struct inode *inode, struct file *file)
423 {
424 struct rpc_clnt *clnt = NULL;
425 int ret = single_open(file, rpc_show_info, NULL);
426
427 if (!ret) {
428 struct seq_file *m = file->private_data;
429
430 spin_lock(&file->f_path.dentry->d_lock);
431 if (!d_unhashed(file->f_path.dentry))
432 clnt = RPC_I(inode)->private;
433 if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) {
434 spin_unlock(&file->f_path.dentry->d_lock);
435 m->private = clnt;
436 } else {
437 spin_unlock(&file->f_path.dentry->d_lock);
438 single_release(inode, file);
439 ret = -EINVAL;
440 }
441 }
442 return ret;
443 }
444
445 static int
446 rpc_info_release(struct inode *inode, struct file *file)
447 {
448 struct seq_file *m = file->private_data;
449 struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
450
451 if (clnt)
452 rpc_release_client(clnt);
453 return single_release(inode, file);
454 }
455
456 static const struct file_operations rpc_info_operations = {
457 .owner = THIS_MODULE,
458 .open = rpc_info_open,
459 .read = seq_read,
460 .llseek = seq_lseek,
461 .release = rpc_info_release,
462 };
463
464
465 /*
466 * Description of fs contents.
467 */
468 struct rpc_filelist {
469 const char *name;
470 const struct file_operations *i_fop;
471 umode_t mode;
472 };
473
474 static int rpc_delete_dentry(const struct dentry *dentry)
475 {
476 return 1;
477 }
478
479 static const struct dentry_operations rpc_dentry_operations = {
480 .d_delete = rpc_delete_dentry,
481 };
482
483 /*
484 * Lookup the data. This is trivial - if the dentry didn't already
485 * exist, we know it is negative.
486 */
487 static struct dentry *
488 rpc_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
489 {
490 if (dentry->d_name.len > NAME_MAX)
491 return ERR_PTR(-ENAMETOOLONG);
492 d_add(dentry, NULL);
493 return NULL;
494 }
495
496 static const struct inode_operations rpc_dir_inode_operations = {
497 .lookup = rpc_lookup,
498 };
499
500 static struct inode *
501 rpc_get_inode(struct super_block *sb, umode_t mode)
502 {
503 struct inode *inode = new_inode(sb);
504 if (!inode)
505 return NULL;
506 inode->i_ino = get_next_ino();
507 inode->i_mode = mode;
508 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
509 switch (mode & S_IFMT) {
510 case S_IFDIR:
511 inode->i_fop = &simple_dir_operations;
512 inode->i_op = &rpc_dir_inode_operations;
513 inc_nlink(inode);
514 default:
515 break;
516 }
517 return inode;
518 }
519
520 static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
521 umode_t mode,
522 const struct file_operations *i_fop,
523 void *private)
524 {
525 struct inode *inode;
526
527 d_drop(dentry);
528 inode = rpc_get_inode(dir->i_sb, mode);
529 if (!inode)
530 goto out_err;
531 inode->i_ino = iunique(dir->i_sb, 100);
532 if (i_fop)
533 inode->i_fop = i_fop;
534 if (private)
535 rpc_inode_setowner(inode, private);
536 d_add(dentry, inode);
537 return 0;
538 out_err:
539 printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
540 __FILE__, __func__, dentry->d_name.name);
541 dput(dentry);
542 return -ENOMEM;
543 }
544
545 static int __rpc_create(struct inode *dir, struct dentry *dentry,
546 umode_t mode,
547 const struct file_operations *i_fop,
548 void *private)
549 {
550 int err;
551
552 err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
553 if (err)
554 return err;
555 fsnotify_create(dir, dentry);
556 return 0;
557 }
558
559 static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
560 umode_t mode,
561 const struct file_operations *i_fop,
562 void *private)
563 {
564 int err;
565
566 err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
567 if (err)
568 return err;
569 inc_nlink(dir);
570 fsnotify_mkdir(dir, dentry);
571 return 0;
572 }
573
574 static void
575 init_pipe(struct rpc_pipe *pipe)
576 {
577 pipe->nreaders = 0;
578 pipe->nwriters = 0;
579 INIT_LIST_HEAD(&pipe->in_upcall);
580 INIT_LIST_HEAD(&pipe->in_downcall);
581 INIT_LIST_HEAD(&pipe->pipe);
582 pipe->pipelen = 0;
583 INIT_DELAYED_WORK(&pipe->queue_timeout,
584 rpc_timeout_upcall_queue);
585 pipe->ops = NULL;
586 spin_lock_init(&pipe->lock);
587 pipe->dentry = NULL;
588 }
589
590 void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
591 {
592 kfree(pipe);
593 }
594 EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
595
596 struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
597 {
598 struct rpc_pipe *pipe;
599
600 pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
601 if (!pipe)
602 return ERR_PTR(-ENOMEM);
603 init_pipe(pipe);
604 pipe->ops = ops;
605 pipe->flags = flags;
606 return pipe;
607 }
608 EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
609
610 static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
611 umode_t mode,
612 const struct file_operations *i_fop,
613 void *private,
614 struct rpc_pipe *pipe)
615 {
616 struct rpc_inode *rpci;
617 int err;
618
619 err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
620 if (err)
621 return err;
622 rpci = RPC_I(dentry->d_inode);
623 rpci->private = private;
624 rpci->pipe = pipe;
625 fsnotify_create(dir, dentry);
626 return 0;
627 }
628
629 static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
630 {
631 int ret;
632
633 dget(dentry);
634 ret = simple_rmdir(dir, dentry);
635 d_delete(dentry);
636 dput(dentry);
637 return ret;
638 }
639
640 int rpc_rmdir(struct dentry *dentry)
641 {
642 struct dentry *parent;
643 struct inode *dir;
644 int error;
645
646 parent = dget_parent(dentry);
647 dir = parent->d_inode;
648 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
649 error = __rpc_rmdir(dir, dentry);
650 mutex_unlock(&dir->i_mutex);
651 dput(parent);
652 return error;
653 }
654 EXPORT_SYMBOL_GPL(rpc_rmdir);
655
656 static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
657 {
658 int ret;
659
660 dget(dentry);
661 ret = simple_unlink(dir, dentry);
662 d_delete(dentry);
663 dput(dentry);
664 return ret;
665 }
666
667 static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
668 {
669 struct inode *inode = dentry->d_inode;
670
671 rpc_close_pipes(inode);
672 return __rpc_unlink(dir, dentry);
673 }
674
675 static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
676 const char *name)
677 {
678 struct qstr q = QSTR_INIT(name, strlen(name));
679 struct dentry *dentry = d_hash_and_lookup(parent, &q);
680 if (!dentry) {
681 dentry = d_alloc(parent, &q);
682 if (!dentry)
683 return ERR_PTR(-ENOMEM);
684 }
685 if (dentry->d_inode == NULL)
686 return dentry;
687 dput(dentry);
688 return ERR_PTR(-EEXIST);
689 }
690
691 /*
692 * FIXME: This probably has races.
693 */
694 static void __rpc_depopulate(struct dentry *parent,
695 const struct rpc_filelist *files,
696 int start, int eof)
697 {
698 struct inode *dir = parent->d_inode;
699 struct dentry *dentry;
700 struct qstr name;
701 int i;
702
703 for (i = start; i < eof; i++) {
704 name.name = files[i].name;
705 name.len = strlen(files[i].name);
706 dentry = d_hash_and_lookup(parent, &name);
707
708 if (dentry == NULL)
709 continue;
710 if (dentry->d_inode == NULL)
711 goto next;
712 switch (dentry->d_inode->i_mode & S_IFMT) {
713 default:
714 BUG();
715 case S_IFREG:
716 __rpc_unlink(dir, dentry);
717 break;
718 case S_IFDIR:
719 __rpc_rmdir(dir, dentry);
720 }
721 next:
722 dput(dentry);
723 }
724 }
725
726 static void rpc_depopulate(struct dentry *parent,
727 const struct rpc_filelist *files,
728 int start, int eof)
729 {
730 struct inode *dir = parent->d_inode;
731
732 mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
733 __rpc_depopulate(parent, files, start, eof);
734 mutex_unlock(&dir->i_mutex);
735 }
736
737 static int rpc_populate(struct dentry *parent,
738 const struct rpc_filelist *files,
739 int start, int eof,
740 void *private)
741 {
742 struct inode *dir = parent->d_inode;
743 struct dentry *dentry;
744 int i, err;
745
746 mutex_lock(&dir->i_mutex);
747 for (i = start; i < eof; i++) {
748 dentry = __rpc_lookup_create_exclusive(parent, files[i].name);
749 err = PTR_ERR(dentry);
750 if (IS_ERR(dentry))
751 goto out_bad;
752 switch (files[i].mode & S_IFMT) {
753 default:
754 BUG();
755 case S_IFREG:
756 err = __rpc_create(dir, dentry,
757 files[i].mode,
758 files[i].i_fop,
759 private);
760 break;
761 case S_IFDIR:
762 err = __rpc_mkdir(dir, dentry,
763 files[i].mode,
764 NULL,
765 private);
766 }
767 if (err != 0)
768 goto out_bad;
769 }
770 mutex_unlock(&dir->i_mutex);
771 return 0;
772 out_bad:
773 __rpc_depopulate(parent, files, start, eof);
774 mutex_unlock(&dir->i_mutex);
775 printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
776 __FILE__, __func__, parent->d_name.name);
777 return err;
778 }
779
780 static struct dentry *rpc_mkdir_populate(struct dentry *parent,
781 const char *name, umode_t mode, void *private,
782 int (*populate)(struct dentry *, void *), void *args_populate)
783 {
784 struct dentry *dentry;
785 struct inode *dir = parent->d_inode;
786 int error;
787
788 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
789 dentry = __rpc_lookup_create_exclusive(parent, name);
790 if (IS_ERR(dentry))
791 goto out;
792 error = __rpc_mkdir(dir, dentry, mode, NULL, private);
793 if (error != 0)
794 goto out_err;
795 if (populate != NULL) {
796 error = populate(dentry, args_populate);
797 if (error)
798 goto err_rmdir;
799 }
800 out:
801 mutex_unlock(&dir->i_mutex);
802 return dentry;
803 err_rmdir:
804 __rpc_rmdir(dir, dentry);
805 out_err:
806 dentry = ERR_PTR(error);
807 goto out;
808 }
809
810 static int rpc_rmdir_depopulate(struct dentry *dentry,
811 void (*depopulate)(struct dentry *))
812 {
813 struct dentry *parent;
814 struct inode *dir;
815 int error;
816
817 parent = dget_parent(dentry);
818 dir = parent->d_inode;
819 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
820 if (depopulate != NULL)
821 depopulate(dentry);
822 error = __rpc_rmdir(dir, dentry);
823 mutex_unlock(&dir->i_mutex);
824 dput(parent);
825 return error;
826 }
827
828 /**
829 * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
830 * @parent: dentry of directory to create new "pipe" in
831 * @name: name of pipe
832 * @private: private data to associate with the pipe, for the caller's use
833 * @pipe: &rpc_pipe containing input parameters
834 *
835 * Data is made available for userspace to read by calls to
836 * rpc_queue_upcall(). The actual reads will result in calls to
837 * @ops->upcall, which will be called with the file pointer,
838 * message, and userspace buffer to copy to.
839 *
840 * Writes can come at any time, and do not necessarily have to be
841 * responses to upcalls. They will result in calls to @msg->downcall.
842 *
843 * The @private argument passed here will be available to all these methods
844 * from the file pointer, via RPC_I(file_inode(file))->private.
845 */
846 struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
847 void *private, struct rpc_pipe *pipe)
848 {
849 struct dentry *dentry;
850 struct inode *dir = parent->d_inode;
851 umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR;
852 int err;
853
854 if (pipe->ops->upcall == NULL)
855 umode &= ~S_IRUGO;
856 if (pipe->ops->downcall == NULL)
857 umode &= ~S_IWUGO;
858
859 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
860 dentry = __rpc_lookup_create_exclusive(parent, name);
861 if (IS_ERR(dentry))
862 goto out;
863 err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
864 private, pipe);
865 if (err)
866 goto out_err;
867 out:
868 mutex_unlock(&dir->i_mutex);
869 return dentry;
870 out_err:
871 dentry = ERR_PTR(err);
872 printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
873 __FILE__, __func__, parent->d_name.name, name,
874 err);
875 goto out;
876 }
877 EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
878
879 /**
880 * rpc_unlink - remove a pipe
881 * @dentry: dentry for the pipe, as returned from rpc_mkpipe
882 *
883 * After this call, lookups will no longer find the pipe, and any
884 * attempts to read or write using preexisting opens of the pipe will
885 * return -EPIPE.
886 */
887 int
888 rpc_unlink(struct dentry *dentry)
889 {
890 struct dentry *parent;
891 struct inode *dir;
892 int error = 0;
893
894 parent = dget_parent(dentry);
895 dir = parent->d_inode;
896 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
897 error = __rpc_rmpipe(dir, dentry);
898 mutex_unlock(&dir->i_mutex);
899 dput(parent);
900 return error;
901 }
902 EXPORT_SYMBOL_GPL(rpc_unlink);
903
904 enum {
905 RPCAUTH_info,
906 RPCAUTH_EOF
907 };
908
909 static const struct rpc_filelist authfiles[] = {
910 [RPCAUTH_info] = {
911 .name = "info",
912 .i_fop = &rpc_info_operations,
913 .mode = S_IFREG | S_IRUSR,
914 },
915 };
916
917 static int rpc_clntdir_populate(struct dentry *dentry, void *private)
918 {
919 return rpc_populate(dentry,
920 authfiles, RPCAUTH_info, RPCAUTH_EOF,
921 private);
922 }
923
924 static void rpc_clntdir_depopulate(struct dentry *dentry)
925 {
926 rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
927 }
928
929 /**
930 * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
931 * @dentry: the parent of new directory
932 * @name: the name of new directory
933 * @rpc_client: rpc client to associate with this directory
934 *
935 * This creates a directory at the given @path associated with
936 * @rpc_clnt, which will contain a file named "info" with some basic
937 * information about the client, together with any "pipes" that may
938 * later be created using rpc_mkpipe().
939 */
940 struct dentry *rpc_create_client_dir(struct dentry *dentry,
941 const char *name,
942 struct rpc_clnt *rpc_client)
943 {
944 return rpc_mkdir_populate(dentry, name, S_IRUGO | S_IXUGO, NULL,
945 rpc_clntdir_populate, rpc_client);
946 }
947
948 /**
949 * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
950 * @dentry: dentry for the pipe
951 */
952 int rpc_remove_client_dir(struct dentry *dentry)
953 {
954 return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
955 }
956
957 static const struct rpc_filelist cache_pipefs_files[3] = {
958 [0] = {
959 .name = "channel",
960 .i_fop = &cache_file_operations_pipefs,
961 .mode = S_IFREG|S_IRUSR|S_IWUSR,
962 },
963 [1] = {
964 .name = "content",
965 .i_fop = &content_file_operations_pipefs,
966 .mode = S_IFREG|S_IRUSR,
967 },
968 [2] = {
969 .name = "flush",
970 .i_fop = &cache_flush_operations_pipefs,
971 .mode = S_IFREG|S_IRUSR|S_IWUSR,
972 },
973 };
974
975 static int rpc_cachedir_populate(struct dentry *dentry, void *private)
976 {
977 return rpc_populate(dentry,
978 cache_pipefs_files, 0, 3,
979 private);
980 }
981
982 static void rpc_cachedir_depopulate(struct dentry *dentry)
983 {
984 rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
985 }
986
987 struct dentry *rpc_create_cache_dir(struct dentry *parent, const char *name,
988 umode_t umode, struct cache_detail *cd)
989 {
990 return rpc_mkdir_populate(parent, name, umode, NULL,
991 rpc_cachedir_populate, cd);
992 }
993
994 void rpc_remove_cache_dir(struct dentry *dentry)
995 {
996 rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
997 }
998
999 /*
1000 * populate the filesystem
1001 */
1002 static const struct super_operations s_ops = {
1003 .alloc_inode = rpc_alloc_inode,
1004 .destroy_inode = rpc_destroy_inode,
1005 .statfs = simple_statfs,
1006 };
1007
1008 #define RPCAUTH_GSSMAGIC 0x67596969
1009
1010 /*
1011 * We have a single directory with 1 node in it.
1012 */
1013 enum {
1014 RPCAUTH_lockd,
1015 RPCAUTH_mount,
1016 RPCAUTH_nfs,
1017 RPCAUTH_portmap,
1018 RPCAUTH_statd,
1019 RPCAUTH_nfsd4_cb,
1020 RPCAUTH_cache,
1021 RPCAUTH_nfsd,
1022 RPCAUTH_RootEOF
1023 };
1024
1025 static const struct rpc_filelist files[] = {
1026 [RPCAUTH_lockd] = {
1027 .name = "lockd",
1028 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1029 },
1030 [RPCAUTH_mount] = {
1031 .name = "mount",
1032 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1033 },
1034 [RPCAUTH_nfs] = {
1035 .name = "nfs",
1036 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1037 },
1038 [RPCAUTH_portmap] = {
1039 .name = "portmap",
1040 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1041 },
1042 [RPCAUTH_statd] = {
1043 .name = "statd",
1044 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1045 },
1046 [RPCAUTH_nfsd4_cb] = {
1047 .name = "nfsd4_cb",
1048 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1049 },
1050 [RPCAUTH_cache] = {
1051 .name = "cache",
1052 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1053 },
1054 [RPCAUTH_nfsd] = {
1055 .name = "nfsd",
1056 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1057 },
1058 };
1059
1060 /*
1061 * This call can be used only in RPC pipefs mount notification hooks.
1062 */
1063 struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
1064 const unsigned char *dir_name)
1065 {
1066 struct qstr dir = QSTR_INIT(dir_name, strlen(dir_name));
1067 return d_hash_and_lookup(sb->s_root, &dir);
1068 }
1069 EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
1070
1071 void rpc_pipefs_init_net(struct net *net)
1072 {
1073 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1074
1075 mutex_init(&sn->pipefs_sb_lock);
1076 sn->gssd_running = 1;
1077 sn->pipe_version = -1;
1078 }
1079
1080 /*
1081 * This call will be used for per network namespace operations calls.
1082 * Note: Function will be returned with pipefs_sb_lock taken if superblock was
1083 * found. This lock have to be released by rpc_put_sb_net() when all operations
1084 * will be completed.
1085 */
1086 struct super_block *rpc_get_sb_net(const struct net *net)
1087 {
1088 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1089
1090 mutex_lock(&sn->pipefs_sb_lock);
1091 if (sn->pipefs_sb)
1092 return sn->pipefs_sb;
1093 mutex_unlock(&sn->pipefs_sb_lock);
1094 return NULL;
1095 }
1096 EXPORT_SYMBOL_GPL(rpc_get_sb_net);
1097
1098 void rpc_put_sb_net(const struct net *net)
1099 {
1100 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1101
1102 WARN_ON(sn->pipefs_sb == NULL);
1103 mutex_unlock(&sn->pipefs_sb_lock);
1104 }
1105 EXPORT_SYMBOL_GPL(rpc_put_sb_net);
1106
1107 static int
1108 rpc_fill_super(struct super_block *sb, void *data, int silent)
1109 {
1110 struct inode *inode;
1111 struct dentry *root;
1112 struct net *net = data;
1113 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1114 int err;
1115
1116 sb->s_blocksize = PAGE_CACHE_SIZE;
1117 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1118 sb->s_magic = RPCAUTH_GSSMAGIC;
1119 sb->s_op = &s_ops;
1120 sb->s_d_op = &rpc_dentry_operations;
1121 sb->s_time_gran = 1;
1122
1123 inode = rpc_get_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
1124 sb->s_root = root = d_make_root(inode);
1125 if (!root)
1126 return -ENOMEM;
1127 if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
1128 return -ENOMEM;
1129 dprintk("RPC: sending pipefs MOUNT notification for net %p%s\n",
1130 net, NET_NAME(net));
1131 mutex_lock(&sn->pipefs_sb_lock);
1132 sn->pipefs_sb = sb;
1133 err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1134 RPC_PIPEFS_MOUNT,
1135 sb);
1136 if (err)
1137 goto err_depopulate;
1138 sb->s_fs_info = get_net(net);
1139 mutex_unlock(&sn->pipefs_sb_lock);
1140 return 0;
1141
1142 err_depopulate:
1143 blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1144 RPC_PIPEFS_UMOUNT,
1145 sb);
1146 sn->pipefs_sb = NULL;
1147 __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1148 mutex_unlock(&sn->pipefs_sb_lock);
1149 return err;
1150 }
1151
1152 static struct dentry *
1153 rpc_mount(struct file_system_type *fs_type,
1154 int flags, const char *dev_name, void *data)
1155 {
1156 return mount_ns(fs_type, flags, current->nsproxy->net_ns, rpc_fill_super);
1157 }
1158
1159 static void rpc_kill_sb(struct super_block *sb)
1160 {
1161 struct net *net = sb->s_fs_info;
1162 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1163
1164 mutex_lock(&sn->pipefs_sb_lock);
1165 if (sn->pipefs_sb != sb) {
1166 mutex_unlock(&sn->pipefs_sb_lock);
1167 goto out;
1168 }
1169 sn->pipefs_sb = NULL;
1170 dprintk("RPC: sending pipefs UMOUNT notification for net %p%s\n",
1171 net, NET_NAME(net));
1172 blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1173 RPC_PIPEFS_UMOUNT,
1174 sb);
1175 mutex_unlock(&sn->pipefs_sb_lock);
1176 put_net(net);
1177 out:
1178 kill_litter_super(sb);
1179 }
1180
1181 static struct file_system_type rpc_pipe_fs_type = {
1182 .owner = THIS_MODULE,
1183 .name = "rpc_pipefs",
1184 .mount = rpc_mount,
1185 .kill_sb = rpc_kill_sb,
1186 };
1187 MODULE_ALIAS_FS("rpc_pipefs");
1188 MODULE_ALIAS("rpc_pipefs");
1189
1190 static void
1191 init_once(void *foo)
1192 {
1193 struct rpc_inode *rpci = (struct rpc_inode *) foo;
1194
1195 inode_init_once(&rpci->vfs_inode);
1196 rpci->private = NULL;
1197 rpci->pipe = NULL;
1198 init_waitqueue_head(&rpci->waitq);
1199 }
1200
1201 int register_rpc_pipefs(void)
1202 {
1203 int err;
1204
1205 rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1206 sizeof(struct rpc_inode),
1207 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1208 SLAB_MEM_SPREAD),
1209 init_once);
1210 if (!rpc_inode_cachep)
1211 return -ENOMEM;
1212 err = rpc_clients_notifier_register();
1213 if (err)
1214 goto err_notifier;
1215 err = register_filesystem(&rpc_pipe_fs_type);
1216 if (err)
1217 goto err_register;
1218 return 0;
1219
1220 err_register:
1221 rpc_clients_notifier_unregister();
1222 err_notifier:
1223 kmem_cache_destroy(rpc_inode_cachep);
1224 return err;
1225 }
1226
1227 void unregister_rpc_pipefs(void)
1228 {
1229 rpc_clients_notifier_unregister();
1230 kmem_cache_destroy(rpc_inode_cachep);
1231 unregister_filesystem(&rpc_pipe_fs_type);
1232 }
Linus' kernel tree