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sunrpc: now we can just set ->s_d_op
[linux-2.6.git] / net / sunrpc / rpc_pipe.c
blob260fe72656a10ea2741c53344d7ae429d6692de2
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 static struct inode *
484 rpc_get_inode(struct super_block *sb, umode_t mode)
485 {
486 struct inode *inode = new_inode(sb);
487 if (!inode)
488 return NULL;
489 inode->i_ino = get_next_ino();
490 inode->i_mode = mode;
491 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
492 switch (mode & S_IFMT) {
493 case S_IFDIR:
494 inode->i_fop = &simple_dir_operations;
495 inode->i_op = &simple_dir_inode_operations;
496 inc_nlink(inode);
497 default:
498 break;
499 }
500 return inode;
501 }
502
503 static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
504 umode_t mode,
505 const struct file_operations *i_fop,
506 void *private)
507 {
508 struct inode *inode;
509
510 d_drop(dentry);
511 inode = rpc_get_inode(dir->i_sb, mode);
512 if (!inode)
513 goto out_err;
514 inode->i_ino = iunique(dir->i_sb, 100);
515 if (i_fop)
516 inode->i_fop = i_fop;
517 if (private)
518 rpc_inode_setowner(inode, private);
519 d_add(dentry, inode);
520 return 0;
521 out_err:
522 printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
523 __FILE__, __func__, dentry->d_name.name);
524 dput(dentry);
525 return -ENOMEM;
526 }
527
528 static int __rpc_create(struct inode *dir, struct dentry *dentry,
529 umode_t mode,
530 const struct file_operations *i_fop,
531 void *private)
532 {
533 int err;
534
535 err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
536 if (err)
537 return err;
538 fsnotify_create(dir, dentry);
539 return 0;
540 }
541
542 static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
543 umode_t mode,
544 const struct file_operations *i_fop,
545 void *private)
546 {
547 int err;
548
549 err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
550 if (err)
551 return err;
552 inc_nlink(dir);
553 fsnotify_mkdir(dir, dentry);
554 return 0;
555 }
556
557 static void
558 init_pipe(struct rpc_pipe *pipe)
559 {
560 pipe->nreaders = 0;
561 pipe->nwriters = 0;
562 INIT_LIST_HEAD(&pipe->in_upcall);
563 INIT_LIST_HEAD(&pipe->in_downcall);
564 INIT_LIST_HEAD(&pipe->pipe);
565 pipe->pipelen = 0;
566 INIT_DELAYED_WORK(&pipe->queue_timeout,
567 rpc_timeout_upcall_queue);
568 pipe->ops = NULL;
569 spin_lock_init(&pipe->lock);
570 pipe->dentry = NULL;
571 }
572
573 void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
574 {
575 kfree(pipe);
576 }
577 EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
578
579 struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
580 {
581 struct rpc_pipe *pipe;
582
583 pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
584 if (!pipe)
585 return ERR_PTR(-ENOMEM);
586 init_pipe(pipe);
587 pipe->ops = ops;
588 pipe->flags = flags;
589 return pipe;
590 }
591 EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
592
593 static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
594 umode_t mode,
595 const struct file_operations *i_fop,
596 void *private,
597 struct rpc_pipe *pipe)
598 {
599 struct rpc_inode *rpci;
600 int err;
601
602 err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
603 if (err)
604 return err;
605 rpci = RPC_I(dentry->d_inode);
606 rpci->private = private;
607 rpci->pipe = pipe;
608 fsnotify_create(dir, dentry);
609 return 0;
610 }
611
612 static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
613 {
614 int ret;
615
616 dget(dentry);
617 ret = simple_rmdir(dir, dentry);
618 d_delete(dentry);
619 dput(dentry);
620 return ret;
621 }
622
623 int rpc_rmdir(struct dentry *dentry)
624 {
625 struct dentry *parent;
626 struct inode *dir;
627 int error;
628
629 parent = dget_parent(dentry);
630 dir = parent->d_inode;
631 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
632 error = __rpc_rmdir(dir, dentry);
633 mutex_unlock(&dir->i_mutex);
634 dput(parent);
635 return error;
636 }
637 EXPORT_SYMBOL_GPL(rpc_rmdir);
638
639 static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
640 {
641 int ret;
642
643 dget(dentry);
644 ret = simple_unlink(dir, dentry);
645 d_delete(dentry);
646 dput(dentry);
647 return ret;
648 }
649
650 static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
651 {
652 struct inode *inode = dentry->d_inode;
653
654 rpc_close_pipes(inode);
655 return __rpc_unlink(dir, dentry);
656 }
657
658 static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
659 const char *name)
660 {
661 struct qstr q = QSTR_INIT(name, strlen(name));
662 struct dentry *dentry = d_hash_and_lookup(parent, &q);
663 if (!dentry) {
664 dentry = d_alloc(parent, &q);
665 if (!dentry)
666 return ERR_PTR(-ENOMEM);
667 }
668 if (dentry->d_inode == NULL)
669 return dentry;
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 dentry = d_hash_and_lookup(parent, &name);
690
691 if (dentry == NULL)
692 continue;
693 if (dentry->d_inode == NULL)
694 goto next;
695 switch (dentry->d_inode->i_mode & S_IFMT) {
696 default:
697 BUG();
698 case S_IFREG:
699 __rpc_unlink(dir, dentry);
700 break;
701 case S_IFDIR:
702 __rpc_rmdir(dir, dentry);
703 }
704 next:
705 dput(dentry);
706 }
707 }
708
709 static void rpc_depopulate(struct dentry *parent,
710 const struct rpc_filelist *files,
711 int start, int eof)
712 {
713 struct inode *dir = parent->d_inode;
714
715 mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
716 __rpc_depopulate(parent, files, start, eof);
717 mutex_unlock(&dir->i_mutex);
718 }
719
720 static int rpc_populate(struct dentry *parent,
721 const struct rpc_filelist *files,
722 int start, int eof,
723 void *private)
724 {
725 struct inode *dir = parent->d_inode;
726 struct dentry *dentry;
727 int i, err;
728
729 mutex_lock(&dir->i_mutex);
730 for (i = start; i < eof; i++) {
731 dentry = __rpc_lookup_create_exclusive(parent, files[i].name);
732 err = PTR_ERR(dentry);
733 if (IS_ERR(dentry))
734 goto out_bad;
735 switch (files[i].mode & S_IFMT) {
736 default:
737 BUG();
738 case S_IFREG:
739 err = __rpc_create(dir, dentry,
740 files[i].mode,
741 files[i].i_fop,
742 private);
743 break;
744 case S_IFDIR:
745 err = __rpc_mkdir(dir, dentry,
746 files[i].mode,
747 NULL,
748 private);
749 }
750 if (err != 0)
751 goto out_bad;
752 }
753 mutex_unlock(&dir->i_mutex);
754 return 0;
755 out_bad:
756 __rpc_depopulate(parent, files, start, eof);
757 mutex_unlock(&dir->i_mutex);
758 printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
759 __FILE__, __func__, parent->d_name.name);
760 return err;
761 }
762
763 static struct dentry *rpc_mkdir_populate(struct dentry *parent,
764 const char *name, umode_t mode, void *private,
765 int (*populate)(struct dentry *, void *), void *args_populate)
766 {
767 struct dentry *dentry;
768 struct inode *dir = parent->d_inode;
769 int error;
770
771 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
772 dentry = __rpc_lookup_create_exclusive(parent, name);
773 if (IS_ERR(dentry))
774 goto out;
775 error = __rpc_mkdir(dir, dentry, mode, NULL, private);
776 if (error != 0)
777 goto out_err;
778 if (populate != NULL) {
779 error = populate(dentry, args_populate);
780 if (error)
781 goto err_rmdir;
782 }
783 out:
784 mutex_unlock(&dir->i_mutex);
785 return dentry;
786 err_rmdir:
787 __rpc_rmdir(dir, dentry);
788 out_err:
789 dentry = ERR_PTR(error);
790 goto out;
791 }
792
793 static int rpc_rmdir_depopulate(struct dentry *dentry,
794 void (*depopulate)(struct dentry *))
795 {
796 struct dentry *parent;
797 struct inode *dir;
798 int error;
799
800 parent = dget_parent(dentry);
801 dir = parent->d_inode;
802 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
803 if (depopulate != NULL)
804 depopulate(dentry);
805 error = __rpc_rmdir(dir, dentry);
806 mutex_unlock(&dir->i_mutex);
807 dput(parent);
808 return error;
809 }
810
811 /**
812 * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
813 * @parent: dentry of directory to create new "pipe" in
814 * @name: name of pipe
815 * @private: private data to associate with the pipe, for the caller's use
816 * @pipe: &rpc_pipe containing input parameters
817 *
818 * Data is made available for userspace to read by calls to
819 * rpc_queue_upcall(). The actual reads will result in calls to
820 * @ops->upcall, which will be called with the file pointer,
821 * message, and userspace buffer to copy to.
822 *
823 * Writes can come at any time, and do not necessarily have to be
824 * responses to upcalls. They will result in calls to @msg->downcall.
825 *
826 * The @private argument passed here will be available to all these methods
827 * from the file pointer, via RPC_I(file_inode(file))->private.
828 */
829 struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
830 void *private, struct rpc_pipe *pipe)
831 {
832 struct dentry *dentry;
833 struct inode *dir = parent->d_inode;
834 umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR;
835 int err;
836
837 if (pipe->ops->upcall == NULL)
838 umode &= ~S_IRUGO;
839 if (pipe->ops->downcall == NULL)
840 umode &= ~S_IWUGO;
841
842 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
843 dentry = __rpc_lookup_create_exclusive(parent, name);
844 if (IS_ERR(dentry))
845 goto out;
846 err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
847 private, pipe);
848 if (err)
849 goto out_err;
850 out:
851 mutex_unlock(&dir->i_mutex);
852 return dentry;
853 out_err:
854 dentry = ERR_PTR(err);
855 printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
856 __FILE__, __func__, parent->d_name.name, name,
857 err);
858 goto out;
859 }
860 EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
861
862 /**
863 * rpc_unlink - remove a pipe
864 * @dentry: dentry for the pipe, as returned from rpc_mkpipe
865 *
866 * After this call, lookups will no longer find the pipe, and any
867 * attempts to read or write using preexisting opens of the pipe will
868 * return -EPIPE.
869 */
870 int
871 rpc_unlink(struct dentry *dentry)
872 {
873 struct dentry *parent;
874 struct inode *dir;
875 int error = 0;
876
877 parent = dget_parent(dentry);
878 dir = parent->d_inode;
879 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
880 error = __rpc_rmpipe(dir, dentry);
881 mutex_unlock(&dir->i_mutex);
882 dput(parent);
883 return error;
884 }
885 EXPORT_SYMBOL_GPL(rpc_unlink);
886
887 enum {
888 RPCAUTH_info,
889 RPCAUTH_EOF
890 };
891
892 static const struct rpc_filelist authfiles[] = {
893 [RPCAUTH_info] = {
894 .name = "info",
895 .i_fop = &rpc_info_operations,
896 .mode = S_IFREG | S_IRUSR,
897 },
898 };
899
900 static int rpc_clntdir_populate(struct dentry *dentry, void *private)
901 {
902 return rpc_populate(dentry,
903 authfiles, RPCAUTH_info, RPCAUTH_EOF,
904 private);
905 }
906
907 static void rpc_clntdir_depopulate(struct dentry *dentry)
908 {
909 rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
910 }
911
912 /**
913 * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
914 * @dentry: the parent of new directory
915 * @name: the name of new directory
916 * @rpc_client: rpc client to associate with this directory
917 *
918 * This creates a directory at the given @path associated with
919 * @rpc_clnt, which will contain a file named "info" with some basic
920 * information about the client, together with any "pipes" that may
921 * later be created using rpc_mkpipe().
922 */
923 struct dentry *rpc_create_client_dir(struct dentry *dentry,
924 const char *name,
925 struct rpc_clnt *rpc_client)
926 {
927 return rpc_mkdir_populate(dentry, name, S_IRUGO | S_IXUGO, NULL,
928 rpc_clntdir_populate, rpc_client);
929 }
930
931 /**
932 * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
933 * @dentry: dentry for the pipe
934 */
935 int rpc_remove_client_dir(struct dentry *dentry)
936 {
937 return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
938 }
939
940 static const struct rpc_filelist cache_pipefs_files[3] = {
941 [0] = {
942 .name = "channel",
943 .i_fop = &cache_file_operations_pipefs,
944 .mode = S_IFREG|S_IRUSR|S_IWUSR,
945 },
946 [1] = {
947 .name = "content",
948 .i_fop = &content_file_operations_pipefs,
949 .mode = S_IFREG|S_IRUSR,
950 },
951 [2] = {
952 .name = "flush",
953 .i_fop = &cache_flush_operations_pipefs,
954 .mode = S_IFREG|S_IRUSR|S_IWUSR,
955 },
956 };
957
958 static int rpc_cachedir_populate(struct dentry *dentry, void *private)
959 {
960 return rpc_populate(dentry,
961 cache_pipefs_files, 0, 3,
962 private);
963 }
964
965 static void rpc_cachedir_depopulate(struct dentry *dentry)
966 {
967 rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
968 }
969
970 struct dentry *rpc_create_cache_dir(struct dentry *parent, const char *name,
971 umode_t umode, struct cache_detail *cd)
972 {
973 return rpc_mkdir_populate(parent, name, umode, NULL,
974 rpc_cachedir_populate, cd);
975 }
976
977 void rpc_remove_cache_dir(struct dentry *dentry)
978 {
979 rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
980 }
981
982 /*
983 * populate the filesystem
984 */
985 static const struct super_operations s_ops = {
986 .alloc_inode = rpc_alloc_inode,
987 .destroy_inode = rpc_destroy_inode,
988 .statfs = simple_statfs,
989 };
990
991 #define RPCAUTH_GSSMAGIC 0x67596969
992
993 /*
994 * We have a single directory with 1 node in it.
995 */
996 enum {
997 RPCAUTH_lockd,
998 RPCAUTH_mount,
999 RPCAUTH_nfs,
1000 RPCAUTH_portmap,
1001 RPCAUTH_statd,
1002 RPCAUTH_nfsd4_cb,
1003 RPCAUTH_cache,
1004 RPCAUTH_nfsd,
1005 RPCAUTH_RootEOF
1006 };
1007
1008 static const struct rpc_filelist files[] = {
1009 [RPCAUTH_lockd] = {
1010 .name = "lockd",
1011 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1012 },
1013 [RPCAUTH_mount] = {
1014 .name = "mount",
1015 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1016 },
1017 [RPCAUTH_nfs] = {
1018 .name = "nfs",
1019 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1020 },
1021 [RPCAUTH_portmap] = {
1022 .name = "portmap",
1023 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1024 },
1025 [RPCAUTH_statd] = {
1026 .name = "statd",
1027 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1028 },
1029 [RPCAUTH_nfsd4_cb] = {
1030 .name = "nfsd4_cb",
1031 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1032 },
1033 [RPCAUTH_cache] = {
1034 .name = "cache",
1035 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1036 },
1037 [RPCAUTH_nfsd] = {
1038 .name = "nfsd",
1039 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1040 },
1041 };
1042
1043 /*
1044 * This call can be used only in RPC pipefs mount notification hooks.
1045 */
1046 struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
1047 const unsigned char *dir_name)
1048 {
1049 struct qstr dir = QSTR_INIT(dir_name, strlen(dir_name));
1050 return d_hash_and_lookup(sb->s_root, &dir);
1051 }
1052 EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
1053
1054 void rpc_pipefs_init_net(struct net *net)
1055 {
1056 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1057
1058 mutex_init(&sn->pipefs_sb_lock);
1059 sn->gssd_running = 1;
1060 sn->pipe_version = -1;
1061 }
1062
1063 /*
1064 * This call will be used for per network namespace operations calls.
1065 * Note: Function will be returned with pipefs_sb_lock taken if superblock was
1066 * found. This lock have to be released by rpc_put_sb_net() when all operations
1067 * will be completed.
1068 */
1069 struct super_block *rpc_get_sb_net(const struct net *net)
1070 {
1071 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1072
1073 mutex_lock(&sn->pipefs_sb_lock);
1074 if (sn->pipefs_sb)
1075 return sn->pipefs_sb;
1076 mutex_unlock(&sn->pipefs_sb_lock);
1077 return NULL;
1078 }
1079 EXPORT_SYMBOL_GPL(rpc_get_sb_net);
1080
1081 void rpc_put_sb_net(const struct net *net)
1082 {
1083 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1084
1085 WARN_ON(sn->pipefs_sb == NULL);
1086 mutex_unlock(&sn->pipefs_sb_lock);
1087 }
1088 EXPORT_SYMBOL_GPL(rpc_put_sb_net);
1089
1090 static int
1091 rpc_fill_super(struct super_block *sb, void *data, int silent)
1092 {
1093 struct inode *inode;
1094 struct dentry *root;
1095 struct net *net = data;
1096 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1097 int err;
1098
1099 sb->s_blocksize = PAGE_CACHE_SIZE;
1100 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1101 sb->s_magic = RPCAUTH_GSSMAGIC;
1102 sb->s_op = &s_ops;
1103 sb->s_d_op = &rpc_dentry_operations;
1104 sb->s_time_gran = 1;
1105
1106 inode = rpc_get_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
1107 sb->s_root = root = d_make_root(inode);
1108 if (!root)
1109 return -ENOMEM;
1110 if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
1111 return -ENOMEM;
1112 dprintk("RPC: sending pipefs MOUNT notification for net %p%s\n",
1113 net, NET_NAME(net));
1114 sn->pipefs_sb = sb;
1115 err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1116 RPC_PIPEFS_MOUNT,
1117 sb);
1118 if (err)
1119 goto err_depopulate;
1120 sb->s_fs_info = get_net(net);
1121 return 0;
1122
1123 err_depopulate:
1124 blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1125 RPC_PIPEFS_UMOUNT,
1126 sb);
1127 sn->pipefs_sb = NULL;
1128 __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1129 return err;
1130 }
1131
1132 static struct dentry *
1133 rpc_mount(struct file_system_type *fs_type,
1134 int flags, const char *dev_name, void *data)
1135 {
1136 return mount_ns(fs_type, flags, current->nsproxy->net_ns, rpc_fill_super);
1137 }
1138
1139 static void rpc_kill_sb(struct super_block *sb)
1140 {
1141 struct net *net = sb->s_fs_info;
1142 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1143
1144 mutex_lock(&sn->pipefs_sb_lock);
1145 if (sn->pipefs_sb != sb) {
1146 mutex_unlock(&sn->pipefs_sb_lock);
1147 goto out;
1148 }
1149 sn->pipefs_sb = NULL;
1150 mutex_unlock(&sn->pipefs_sb_lock);
1151 dprintk("RPC: sending pipefs UMOUNT notification for net %p%s\n",
1152 net, NET_NAME(net));
1153 blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1154 RPC_PIPEFS_UMOUNT,
1155 sb);
1156 put_net(net);
1157 out:
1158 kill_litter_super(sb);
1159 }
1160
1161 static struct file_system_type rpc_pipe_fs_type = {
1162 .owner = THIS_MODULE,
1163 .name = "rpc_pipefs",
1164 .mount = rpc_mount,
1165 .kill_sb = rpc_kill_sb,
1166 };
1167 MODULE_ALIAS_FS("rpc_pipefs");
1168 MODULE_ALIAS("rpc_pipefs");
1169
1170 static void
1171 init_once(void *foo)
1172 {
1173 struct rpc_inode *rpci = (struct rpc_inode *) foo;
1174
1175 inode_init_once(&rpci->vfs_inode);
1176 rpci->private = NULL;
1177 rpci->pipe = NULL;
1178 init_waitqueue_head(&rpci->waitq);
1179 }
1180
1181 int register_rpc_pipefs(void)
1182 {
1183 int err;
1184
1185 rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1186 sizeof(struct rpc_inode),
1187 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1188 SLAB_MEM_SPREAD),
1189 init_once);
1190 if (!rpc_inode_cachep)
1191 return -ENOMEM;
1192 err = rpc_clients_notifier_register();
1193 if (err)
1194 goto err_notifier;
1195 err = register_filesystem(&rpc_pipe_fs_type);
1196 if (err)
1197 goto err_register;
1198 return 0;
1199
1200 err_register:
1201 rpc_clients_notifier_unregister();
1202 err_notifier:
1203 kmem_cache_destroy(rpc_inode_cachep);
1204 return err;
1205 }
1206
1207 void unregister_rpc_pipefs(void)
1208 {
1209 rpc_clients_notifier_unregister();
1210 kmem_cache_destroy(rpc_inode_cachep);
1211 unregister_filesystem(&rpc_pipe_fs_type);
1212 }
Linus' kernel tree