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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * net/sunrpc/rpc_pipe.c
4 *
5 * Userland/kernel interface for rpcauth_gss.
6 * Code shamelessly plagiarized from fs/nfsd/nfsctl.c
7 * and fs/sysfs/inode.c
8 *
9 * Copyright (c) 2002, Trond Myklebust <trond.myklebust@fys.uio.no>
10 *
11 */
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/string.h>
15#include <linux/pagemap.h>
16#include <linux/mount.h>
17#include <linux/fs_context.h>
18#include <linux/namei.h>
19#include <linux/fsnotify.h>
20#include <linux/kernel.h>
21#include <linux/rcupdate.h>
22#include <linux/utsname.h>
23
24#include <asm/ioctls.h>
25#include <linux/poll.h>
26#include <linux/wait.h>
27#include <linux/seq_file.h>
28
29#include <linux/sunrpc/clnt.h>
30#include <linux/workqueue.h>
31#include <linux/sunrpc/rpc_pipe_fs.h>
32#include <linux/sunrpc/cache.h>
33#include <linux/nsproxy.h>
34#include <linux/notifier.h>
35
36#include "netns.h"
37#include "sunrpc.h"
38
39#define RPCDBG_FACILITY RPCDBG_DEBUG
40
41#define NET_NAME(net) ((net == &init_net) ? " (init_net)" : "")
42
43static struct file_system_type rpc_pipe_fs_type;
44static const struct rpc_pipe_ops gssd_dummy_pipe_ops;
45
46static struct kmem_cache *rpc_inode_cachep __read_mostly;
47
48#define RPC_UPCALL_TIMEOUT (30*HZ)
49
50static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
51
52int rpc_pipefs_notifier_register(struct notifier_block *nb)
53{
54 return blocking_notifier_chain_register(&rpc_pipefs_notifier_list, nb);
55}
56EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
57
58void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
59{
60 blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
61}
62EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
63
64static void rpc_purge_list(wait_queue_head_t *waitq, struct list_head *head,
65 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
66{
67 struct rpc_pipe_msg *msg;
68
69 if (list_empty(head))
70 return;
71 do {
72 msg = list_entry(head->next, struct rpc_pipe_msg, list);
73 list_del_init(&msg->list);
74 msg->errno = err;
75 destroy_msg(msg);
76 } while (!list_empty(head));
77
78 if (waitq)
79 wake_up(waitq);
80}
81
82static void
83rpc_timeout_upcall_queue(struct work_struct *work)
84{
85 LIST_HEAD(free_list);
86 struct rpc_pipe *pipe =
87 container_of(work, struct rpc_pipe, queue_timeout.work);
88 void (*destroy_msg)(struct rpc_pipe_msg *);
89 struct dentry *dentry;
90
91 spin_lock(&pipe->lock);
92 destroy_msg = pipe->ops->destroy_msg;
93 if (pipe->nreaders == 0) {
94 list_splice_init(&pipe->pipe, &free_list);
95 pipe->pipelen = 0;
96 }
97 dentry = dget(pipe->dentry);
98 spin_unlock(&pipe->lock);
99 rpc_purge_list(dentry ? &RPC_I(d_inode(dentry))->waitq : NULL,
100 &free_list, destroy_msg, -ETIMEDOUT);
101 dput(dentry);
102}
103
104ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
105 char __user *dst, size_t buflen)
106{
107 char *data = (char *)msg->data + msg->copied;
108 size_t mlen = min(msg->len - msg->copied, buflen);
109 unsigned long left;
110
111 left = copy_to_user(dst, data, mlen);
112 if (left == mlen) {
113 msg->errno = -EFAULT;
114 return -EFAULT;
115 }
116
117 mlen -= left;
118 msg->copied += mlen;
119 msg->errno = 0;
120 return mlen;
121}
122EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
123
124/**
125 * rpc_queue_upcall - queue an upcall message to userspace
126 * @pipe: upcall pipe on which to queue given message
127 * @msg: message to queue
128 *
129 * Call with an @inode created by rpc_mkpipe() to queue an upcall.
130 * A userspace process may then later read the upcall by performing a
131 * read on an open file for this inode. It is up to the caller to
132 * initialize the fields of @msg (other than @msg->list) appropriately.
133 */
134int
135rpc_queue_upcall(struct rpc_pipe *pipe, struct rpc_pipe_msg *msg)
136{
137 int res = -EPIPE;
138 struct dentry *dentry;
139
140 spin_lock(&pipe->lock);
141 if (pipe->nreaders) {
142 list_add_tail(&msg->list, &pipe->pipe);
143 pipe->pipelen += msg->len;
144 res = 0;
145 } else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
146 if (list_empty(&pipe->pipe))
147 queue_delayed_work(rpciod_workqueue,
148 &pipe->queue_timeout,
149 RPC_UPCALL_TIMEOUT);
150 list_add_tail(&msg->list, &pipe->pipe);
151 pipe->pipelen += msg->len;
152 res = 0;
153 }
154 dentry = dget(pipe->dentry);
155 spin_unlock(&pipe->lock);
156 if (dentry) {
157 wake_up(&RPC_I(d_inode(dentry))->waitq);
158 dput(dentry);
159 }
160 return res;
161}
162EXPORT_SYMBOL_GPL(rpc_queue_upcall);
163
164static inline void
165rpc_inode_setowner(struct inode *inode, void *private)
166{
167 RPC_I(inode)->private = private;
168}
169
170static void
171rpc_close_pipes(struct inode *inode)
172{
173 struct rpc_pipe *pipe = RPC_I(inode)->pipe;
174 int need_release;
175 LIST_HEAD(free_list);
176
177 inode_lock(inode);
178 spin_lock(&pipe->lock);
179 need_release = pipe->nreaders != 0 || pipe->nwriters != 0;
180 pipe->nreaders = 0;
181 list_splice_init(&pipe->in_upcall, &free_list);
182 list_splice_init(&pipe->pipe, &free_list);
183 pipe->pipelen = 0;
184 pipe->dentry = NULL;
185 spin_unlock(&pipe->lock);
186 rpc_purge_list(&RPC_I(inode)->waitq, &free_list, pipe->ops->destroy_msg, -EPIPE);
187 pipe->nwriters = 0;
188 if (need_release && pipe->ops->release_pipe)
189 pipe->ops->release_pipe(inode);
190 cancel_delayed_work_sync(&pipe->queue_timeout);
191 rpc_inode_setowner(inode, NULL);
192 RPC_I(inode)->pipe = NULL;
193 inode_unlock(inode);
194}
195
196static struct inode *
197rpc_alloc_inode(struct super_block *sb)
198{
199 struct rpc_inode *rpci;
200 rpci = alloc_inode_sb(sb, rpc_inode_cachep, GFP_KERNEL);
201 if (!rpci)
202 return NULL;
203 return &rpci->vfs_inode;
204}
205
206static void
207rpc_free_inode(struct inode *inode)
208{
209 kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
210}
211
212static int
213rpc_pipe_open(struct inode *inode, struct file *filp)
214{
215 struct rpc_pipe *pipe;
216 int first_open;
217 int res = -ENXIO;
218
219 inode_lock(inode);
220 pipe = RPC_I(inode)->pipe;
221 if (pipe == NULL)
222 goto out;
223 first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
224 if (first_open && pipe->ops->open_pipe) {
225 res = pipe->ops->open_pipe(inode);
226 if (res)
227 goto out;
228 }
229 if (filp->f_mode & FMODE_READ)
230 pipe->nreaders++;
231 if (filp->f_mode & FMODE_WRITE)
232 pipe->nwriters++;
233 res = 0;
234out:
235 inode_unlock(inode);
236 return res;
237}
238
239static int
240rpc_pipe_release(struct inode *inode, struct file *filp)
241{
242 struct rpc_pipe *pipe;
243 struct rpc_pipe_msg *msg;
244 int last_close;
245
246 inode_lock(inode);
247 pipe = RPC_I(inode)->pipe;
248 if (pipe == NULL)
249 goto out;
250 msg = filp->private_data;
251 if (msg != NULL) {
252 spin_lock(&pipe->lock);
253 msg->errno = -EAGAIN;
254 list_del_init(&msg->list);
255 spin_unlock(&pipe->lock);
256 pipe->ops->destroy_msg(msg);
257 }
258 if (filp->f_mode & FMODE_WRITE)
259 pipe->nwriters --;
260 if (filp->f_mode & FMODE_READ) {
261 pipe->nreaders --;
262 if (pipe->nreaders == 0) {
263 LIST_HEAD(free_list);
264 spin_lock(&pipe->lock);
265 list_splice_init(&pipe->pipe, &free_list);
266 pipe->pipelen = 0;
267 spin_unlock(&pipe->lock);
268 rpc_purge_list(&RPC_I(inode)->waitq, &free_list,
269 pipe->ops->destroy_msg, -EAGAIN);
270 }
271 }
272 last_close = pipe->nwriters == 0 && pipe->nreaders == 0;
273 if (last_close && pipe->ops->release_pipe)
274 pipe->ops->release_pipe(inode);
275out:
276 inode_unlock(inode);
277 return 0;
278}
279
280static ssize_t
281rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
282{
283 struct inode *inode = file_inode(filp);
284 struct rpc_pipe *pipe;
285 struct rpc_pipe_msg *msg;
286 int res = 0;
287
288 inode_lock(inode);
289 pipe = RPC_I(inode)->pipe;
290 if (pipe == NULL) {
291 res = -EPIPE;
292 goto out_unlock;
293 }
294 msg = filp->private_data;
295 if (msg == NULL) {
296 spin_lock(&pipe->lock);
297 if (!list_empty(&pipe->pipe)) {
298 msg = list_entry(pipe->pipe.next,
299 struct rpc_pipe_msg,
300 list);
301 list_move(&msg->list, &pipe->in_upcall);
302 pipe->pipelen -= msg->len;
303 filp->private_data = msg;
304 msg->copied = 0;
305 }
306 spin_unlock(&pipe->lock);
307 if (msg == NULL)
308 goto out_unlock;
309 }
310 /* NOTE: it is up to the callback to update msg->copied */
311 res = pipe->ops->upcall(filp, msg, buf, len);
312 if (res < 0 || msg->len == msg->copied) {
313 filp->private_data = NULL;
314 spin_lock(&pipe->lock);
315 list_del_init(&msg->list);
316 spin_unlock(&pipe->lock);
317 pipe->ops->destroy_msg(msg);
318 }
319out_unlock:
320 inode_unlock(inode);
321 return res;
322}
323
324static ssize_t
325rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
326{
327 struct inode *inode = file_inode(filp);
328 int res;
329
330 inode_lock(inode);
331 res = -EPIPE;
332 if (RPC_I(inode)->pipe != NULL)
333 res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len);
334 inode_unlock(inode);
335 return res;
336}
337
338static __poll_t
339rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
340{
341 struct inode *inode = file_inode(filp);
342 struct rpc_inode *rpci = RPC_I(inode);
343 __poll_t mask = EPOLLOUT | EPOLLWRNORM;
344
345 poll_wait(filp, &rpci->waitq, wait);
346
347 inode_lock(inode);
348 if (rpci->pipe == NULL)
349 mask |= EPOLLERR | EPOLLHUP;
350 else if (filp->private_data || !list_empty(&rpci->pipe->pipe))
351 mask |= EPOLLIN | EPOLLRDNORM;
352 inode_unlock(inode);
353 return mask;
354}
355
356static long
357rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
358{
359 struct inode *inode = file_inode(filp);
360 struct rpc_pipe *pipe;
361 int len;
362
363 switch (cmd) {
364 case FIONREAD:
365 inode_lock(inode);
366 pipe = RPC_I(inode)->pipe;
367 if (pipe == NULL) {
368 inode_unlock(inode);
369 return -EPIPE;
370 }
371 spin_lock(&pipe->lock);
372 len = pipe->pipelen;
373 if (filp->private_data) {
374 struct rpc_pipe_msg *msg;
375 msg = filp->private_data;
376 len += msg->len - msg->copied;
377 }
378 spin_unlock(&pipe->lock);
379 inode_unlock(inode);
380 return put_user(len, (int __user *)arg);
381 default:
382 return -EINVAL;
383 }
384}
385
386static const struct file_operations rpc_pipe_fops = {
387 .owner = THIS_MODULE,
388 .llseek = no_llseek,
389 .read = rpc_pipe_read,
390 .write = rpc_pipe_write,
391 .poll = rpc_pipe_poll,
392 .unlocked_ioctl = rpc_pipe_ioctl,
393 .open = rpc_pipe_open,
394 .release = rpc_pipe_release,
395};
396
397static int
398rpc_show_info(struct seq_file *m, void *v)
399{
400 struct rpc_clnt *clnt = m->private;
401
402 rcu_read_lock();
403 seq_printf(m, "RPC server: %s\n",
404 rcu_dereference(clnt->cl_xprt)->servername);
405 seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_program->name,
406 clnt->cl_prog, clnt->cl_vers);
407 seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
408 seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
409 seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
410 rcu_read_unlock();
411 return 0;
412}
413
414static int
415rpc_info_open(struct inode *inode, struct file *file)
416{
417 struct rpc_clnt *clnt = NULL;
418 int ret = single_open(file, rpc_show_info, NULL);
419
420 if (!ret) {
421 struct seq_file *m = file->private_data;
422
423 spin_lock(&file->f_path.dentry->d_lock);
424 if (!d_unhashed(file->f_path.dentry))
425 clnt = RPC_I(inode)->private;
426 if (clnt != NULL && refcount_inc_not_zero(&clnt->cl_count)) {
427 spin_unlock(&file->f_path.dentry->d_lock);
428 m->private = clnt;
429 } else {
430 spin_unlock(&file->f_path.dentry->d_lock);
431 single_release(inode, file);
432 ret = -EINVAL;
433 }
434 }
435 return ret;
436}
437
438static int
439rpc_info_release(struct inode *inode, struct file *file)
440{
441 struct seq_file *m = file->private_data;
442 struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
443
444 if (clnt)
445 rpc_release_client(clnt);
446 return single_release(inode, file);
447}
448
449static const struct file_operations rpc_info_operations = {
450 .owner = THIS_MODULE,
451 .open = rpc_info_open,
452 .read = seq_read,
453 .llseek = seq_lseek,
454 .release = rpc_info_release,
455};
456
457
458/*
459 * Description of fs contents.
460 */
461struct rpc_filelist {
462 const char *name;
463 const struct file_operations *i_fop;
464 umode_t mode;
465};
466
467static struct inode *
468rpc_get_inode(struct super_block *sb, umode_t mode)
469{
470 struct inode *inode = new_inode(sb);
471 if (!inode)
472 return NULL;
473 inode->i_ino = get_next_ino();
474 inode->i_mode = mode;
475 simple_inode_init_ts(inode);
476 switch (mode & S_IFMT) {
477 case S_IFDIR:
478 inode->i_fop = &simple_dir_operations;
479 inode->i_op = &simple_dir_inode_operations;
480 inc_nlink(inode);
481 break;
482 default:
483 break;
484 }
485 return inode;
486}
487
488static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
489 umode_t mode,
490 const struct file_operations *i_fop,
491 void *private)
492{
493 struct inode *inode;
494
495 d_drop(dentry);
496 inode = rpc_get_inode(dir->i_sb, mode);
497 if (!inode)
498 goto out_err;
499 inode->i_ino = iunique(dir->i_sb, 100);
500 if (i_fop)
501 inode->i_fop = i_fop;
502 if (private)
503 rpc_inode_setowner(inode, private);
504 d_add(dentry, inode);
505 return 0;
506out_err:
507 printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %pd\n",
508 __FILE__, __func__, dentry);
509 dput(dentry);
510 return -ENOMEM;
511}
512
513static int __rpc_create(struct inode *dir, struct dentry *dentry,
514 umode_t mode,
515 const struct file_operations *i_fop,
516 void *private)
517{
518 int err;
519
520 err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
521 if (err)
522 return err;
523 fsnotify_create(dir, dentry);
524 return 0;
525}
526
527static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
528 umode_t mode,
529 const struct file_operations *i_fop,
530 void *private)
531{
532 int err;
533
534 err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
535 if (err)
536 return err;
537 inc_nlink(dir);
538 fsnotify_mkdir(dir, dentry);
539 return 0;
540}
541
542static void
543init_pipe(struct rpc_pipe *pipe)
544{
545 pipe->nreaders = 0;
546 pipe->nwriters = 0;
547 INIT_LIST_HEAD(&pipe->in_upcall);
548 INIT_LIST_HEAD(&pipe->in_downcall);
549 INIT_LIST_HEAD(&pipe->pipe);
550 pipe->pipelen = 0;
551 INIT_DELAYED_WORK(&pipe->queue_timeout,
552 rpc_timeout_upcall_queue);
553 pipe->ops = NULL;
554 spin_lock_init(&pipe->lock);
555 pipe->dentry = NULL;
556}
557
558void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
559{
560 kfree(pipe);
561}
562EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
563
564struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
565{
566 struct rpc_pipe *pipe;
567
568 pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
569 if (!pipe)
570 return ERR_PTR(-ENOMEM);
571 init_pipe(pipe);
572 pipe->ops = ops;
573 pipe->flags = flags;
574 return pipe;
575}
576EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
577
578static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
579 umode_t mode,
580 const struct file_operations *i_fop,
581 void *private,
582 struct rpc_pipe *pipe)
583{
584 struct rpc_inode *rpci;
585 int err;
586
587 err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
588 if (err)
589 return err;
590 rpci = RPC_I(d_inode(dentry));
591 rpci->private = private;
592 rpci->pipe = pipe;
593 fsnotify_create(dir, dentry);
594 return 0;
595}
596
597static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
598{
599 int ret;
600
601 dget(dentry);
602 ret = simple_rmdir(dir, dentry);
603 d_drop(dentry);
604 if (!ret)
605 fsnotify_rmdir(dir, dentry);
606 dput(dentry);
607 return ret;
608}
609
610static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
611{
612 int ret;
613
614 dget(dentry);
615 ret = simple_unlink(dir, dentry);
616 d_drop(dentry);
617 if (!ret)
618 fsnotify_unlink(dir, dentry);
619 dput(dentry);
620 return ret;
621}
622
623static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
624{
625 struct inode *inode = d_inode(dentry);
626
627 rpc_close_pipes(inode);
628 return __rpc_unlink(dir, dentry);
629}
630
631static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
632 const char *name)
633{
634 struct qstr q = QSTR_INIT(name, strlen(name));
635 struct dentry *dentry = d_hash_and_lookup(parent, &q);
636 if (!dentry) {
637 dentry = d_alloc(parent, &q);
638 if (!dentry)
639 return ERR_PTR(-ENOMEM);
640 }
641 if (d_really_is_negative(dentry))
642 return dentry;
643 dput(dentry);
644 return ERR_PTR(-EEXIST);
645}
646
647/*
648 * FIXME: This probably has races.
649 */
650static void __rpc_depopulate(struct dentry *parent,
651 const struct rpc_filelist *files,
652 int start, int eof)
653{
654 struct inode *dir = d_inode(parent);
655 struct dentry *dentry;
656 struct qstr name;
657 int i;
658
659 for (i = start; i < eof; i++) {
660 name.name = files[i].name;
661 name.len = strlen(files[i].name);
662 dentry = d_hash_and_lookup(parent, &name);
663
664 if (dentry == NULL)
665 continue;
666 if (d_really_is_negative(dentry))
667 goto next;
668 switch (d_inode(dentry)->i_mode & S_IFMT) {
669 default:
670 BUG();
671 case S_IFREG:
672 __rpc_unlink(dir, dentry);
673 break;
674 case S_IFDIR:
675 __rpc_rmdir(dir, dentry);
676 }
677next:
678 dput(dentry);
679 }
680}
681
682static void rpc_depopulate(struct dentry *parent,
683 const struct rpc_filelist *files,
684 int start, int eof)
685{
686 struct inode *dir = d_inode(parent);
687
688 inode_lock_nested(dir, I_MUTEX_CHILD);
689 __rpc_depopulate(parent, files, start, eof);
690 inode_unlock(dir);
691}
692
693static int rpc_populate(struct dentry *parent,
694 const struct rpc_filelist *files,
695 int start, int eof,
696 void *private)
697{
698 struct inode *dir = d_inode(parent);
699 struct dentry *dentry;
700 int i, err;
701
702 inode_lock(dir);
703 for (i = start; i < eof; i++) {
704 dentry = __rpc_lookup_create_exclusive(parent, files[i].name);
705 err = PTR_ERR(dentry);
706 if (IS_ERR(dentry))
707 goto out_bad;
708 switch (files[i].mode & S_IFMT) {
709 default:
710 BUG();
711 case S_IFREG:
712 err = __rpc_create(dir, dentry,
713 files[i].mode,
714 files[i].i_fop,
715 private);
716 break;
717 case S_IFDIR:
718 err = __rpc_mkdir(dir, dentry,
719 files[i].mode,
720 NULL,
721 private);
722 }
723 if (err != 0)
724 goto out_bad;
725 }
726 inode_unlock(dir);
727 return 0;
728out_bad:
729 __rpc_depopulate(parent, files, start, eof);
730 inode_unlock(dir);
731 printk(KERN_WARNING "%s: %s failed to populate directory %pd\n",
732 __FILE__, __func__, parent);
733 return err;
734}
735
736static struct dentry *rpc_mkdir_populate(struct dentry *parent,
737 const char *name, umode_t mode, void *private,
738 int (*populate)(struct dentry *, void *), void *args_populate)
739{
740 struct dentry *dentry;
741 struct inode *dir = d_inode(parent);
742 int error;
743
744 inode_lock_nested(dir, I_MUTEX_PARENT);
745 dentry = __rpc_lookup_create_exclusive(parent, name);
746 if (IS_ERR(dentry))
747 goto out;
748 error = __rpc_mkdir(dir, dentry, mode, NULL, private);
749 if (error != 0)
750 goto out_err;
751 if (populate != NULL) {
752 error = populate(dentry, args_populate);
753 if (error)
754 goto err_rmdir;
755 }
756out:
757 inode_unlock(dir);
758 return dentry;
759err_rmdir:
760 __rpc_rmdir(dir, dentry);
761out_err:
762 dentry = ERR_PTR(error);
763 goto out;
764}
765
766static int rpc_rmdir_depopulate(struct dentry *dentry,
767 void (*depopulate)(struct dentry *))
768{
769 struct dentry *parent;
770 struct inode *dir;
771 int error;
772
773 parent = dget_parent(dentry);
774 dir = d_inode(parent);
775 inode_lock_nested(dir, I_MUTEX_PARENT);
776 if (depopulate != NULL)
777 depopulate(dentry);
778 error = __rpc_rmdir(dir, dentry);
779 inode_unlock(dir);
780 dput(parent);
781 return error;
782}
783
784/**
785 * rpc_mkpipe_dentry - make an rpc_pipefs file for kernel<->userspace
786 * communication
787 * @parent: dentry of directory to create new "pipe" in
788 * @name: name of pipe
789 * @private: private data to associate with the pipe, for the caller's use
790 * @pipe: &rpc_pipe containing input parameters
791 *
792 * Data is made available for userspace to read by calls to
793 * rpc_queue_upcall(). The actual reads will result in calls to
794 * @ops->upcall, which will be called with the file pointer,
795 * message, and userspace buffer to copy to.
796 *
797 * Writes can come at any time, and do not necessarily have to be
798 * responses to upcalls. They will result in calls to @msg->downcall.
799 *
800 * The @private argument passed here will be available to all these methods
801 * from the file pointer, via RPC_I(file_inode(file))->private.
802 */
803struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
804 void *private, struct rpc_pipe *pipe)
805{
806 struct dentry *dentry;
807 struct inode *dir = d_inode(parent);
808 umode_t umode = S_IFIFO | 0600;
809 int err;
810
811 if (pipe->ops->upcall == NULL)
812 umode &= ~0444;
813 if (pipe->ops->downcall == NULL)
814 umode &= ~0222;
815
816 inode_lock_nested(dir, I_MUTEX_PARENT);
817 dentry = __rpc_lookup_create_exclusive(parent, name);
818 if (IS_ERR(dentry))
819 goto out;
820 err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
821 private, pipe);
822 if (err)
823 goto out_err;
824out:
825 inode_unlock(dir);
826 return dentry;
827out_err:
828 dentry = ERR_PTR(err);
829 printk(KERN_WARNING "%s: %s() failed to create pipe %pd/%s (errno = %d)\n",
830 __FILE__, __func__, parent, name,
831 err);
832 goto out;
833}
834EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
835
836/**
837 * rpc_unlink - remove a pipe
838 * @dentry: dentry for the pipe, as returned from rpc_mkpipe
839 *
840 * After this call, lookups will no longer find the pipe, and any
841 * attempts to read or write using preexisting opens of the pipe will
842 * return -EPIPE.
843 */
844int
845rpc_unlink(struct dentry *dentry)
846{
847 struct dentry *parent;
848 struct inode *dir;
849 int error = 0;
850
851 parent = dget_parent(dentry);
852 dir = d_inode(parent);
853 inode_lock_nested(dir, I_MUTEX_PARENT);
854 error = __rpc_rmpipe(dir, dentry);
855 inode_unlock(dir);
856 dput(parent);
857 return error;
858}
859EXPORT_SYMBOL_GPL(rpc_unlink);
860
861/**
862 * rpc_init_pipe_dir_head - initialise a struct rpc_pipe_dir_head
863 * @pdh: pointer to struct rpc_pipe_dir_head
864 */
865void rpc_init_pipe_dir_head(struct rpc_pipe_dir_head *pdh)
866{
867 INIT_LIST_HEAD(&pdh->pdh_entries);
868 pdh->pdh_dentry = NULL;
869}
870EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_head);
871
872/**
873 * rpc_init_pipe_dir_object - initialise a struct rpc_pipe_dir_object
874 * @pdo: pointer to struct rpc_pipe_dir_object
875 * @pdo_ops: pointer to const struct rpc_pipe_dir_object_ops
876 * @pdo_data: pointer to caller-defined data
877 */
878void rpc_init_pipe_dir_object(struct rpc_pipe_dir_object *pdo,
879 const struct rpc_pipe_dir_object_ops *pdo_ops,
880 void *pdo_data)
881{
882 INIT_LIST_HEAD(&pdo->pdo_head);
883 pdo->pdo_ops = pdo_ops;
884 pdo->pdo_data = pdo_data;
885}
886EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_object);
887
888static int
889rpc_add_pipe_dir_object_locked(struct net *net,
890 struct rpc_pipe_dir_head *pdh,
891 struct rpc_pipe_dir_object *pdo)
892{
893 int ret = 0;
894
895 if (pdh->pdh_dentry)
896 ret = pdo->pdo_ops->create(pdh->pdh_dentry, pdo);
897 if (ret == 0)
898 list_add_tail(&pdo->pdo_head, &pdh->pdh_entries);
899 return ret;
900}
901
902static void
903rpc_remove_pipe_dir_object_locked(struct net *net,
904 struct rpc_pipe_dir_head *pdh,
905 struct rpc_pipe_dir_object *pdo)
906{
907 if (pdh->pdh_dentry)
908 pdo->pdo_ops->destroy(pdh->pdh_dentry, pdo);
909 list_del_init(&pdo->pdo_head);
910}
911
912/**
913 * rpc_add_pipe_dir_object - associate a rpc_pipe_dir_object to a directory
914 * @net: pointer to struct net
915 * @pdh: pointer to struct rpc_pipe_dir_head
916 * @pdo: pointer to struct rpc_pipe_dir_object
917 *
918 */
919int
920rpc_add_pipe_dir_object(struct net *net,
921 struct rpc_pipe_dir_head *pdh,
922 struct rpc_pipe_dir_object *pdo)
923{
924 int ret = 0;
925
926 if (list_empty(&pdo->pdo_head)) {
927 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
928
929 mutex_lock(&sn->pipefs_sb_lock);
930 ret = rpc_add_pipe_dir_object_locked(net, pdh, pdo);
931 mutex_unlock(&sn->pipefs_sb_lock);
932 }
933 return ret;
934}
935EXPORT_SYMBOL_GPL(rpc_add_pipe_dir_object);
936
937/**
938 * rpc_remove_pipe_dir_object - remove a rpc_pipe_dir_object from a directory
939 * @net: pointer to struct net
940 * @pdh: pointer to struct rpc_pipe_dir_head
941 * @pdo: pointer to struct rpc_pipe_dir_object
942 *
943 */
944void
945rpc_remove_pipe_dir_object(struct net *net,
946 struct rpc_pipe_dir_head *pdh,
947 struct rpc_pipe_dir_object *pdo)
948{
949 if (!list_empty(&pdo->pdo_head)) {
950 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
951
952 mutex_lock(&sn->pipefs_sb_lock);
953 rpc_remove_pipe_dir_object_locked(net, pdh, pdo);
954 mutex_unlock(&sn->pipefs_sb_lock);
955 }
956}
957EXPORT_SYMBOL_GPL(rpc_remove_pipe_dir_object);
958
959/**
960 * rpc_find_or_alloc_pipe_dir_object
961 * @net: pointer to struct net
962 * @pdh: pointer to struct rpc_pipe_dir_head
963 * @match: match struct rpc_pipe_dir_object to data
964 * @alloc: allocate a new struct rpc_pipe_dir_object
965 * @data: user defined data for match() and alloc()
966 *
967 */
968struct rpc_pipe_dir_object *
969rpc_find_or_alloc_pipe_dir_object(struct net *net,
970 struct rpc_pipe_dir_head *pdh,
971 int (*match)(struct rpc_pipe_dir_object *, void *),
972 struct rpc_pipe_dir_object *(*alloc)(void *),
973 void *data)
974{
975 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
976 struct rpc_pipe_dir_object *pdo;
977
978 mutex_lock(&sn->pipefs_sb_lock);
979 list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) {
980 if (!match(pdo, data))
981 continue;
982 goto out;
983 }
984 pdo = alloc(data);
985 if (!pdo)
986 goto out;
987 rpc_add_pipe_dir_object_locked(net, pdh, pdo);
988out:
989 mutex_unlock(&sn->pipefs_sb_lock);
990 return pdo;
991}
992EXPORT_SYMBOL_GPL(rpc_find_or_alloc_pipe_dir_object);
993
994static void
995rpc_create_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
996{
997 struct rpc_pipe_dir_object *pdo;
998 struct dentry *dir = pdh->pdh_dentry;
999
1000 list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
1001 pdo->pdo_ops->create(dir, pdo);
1002}
1003
1004static void
1005rpc_destroy_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
1006{
1007 struct rpc_pipe_dir_object *pdo;
1008 struct dentry *dir = pdh->pdh_dentry;
1009
1010 list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
1011 pdo->pdo_ops->destroy(dir, pdo);
1012}
1013
1014enum {
1015 RPCAUTH_info,
1016 RPCAUTH_EOF
1017};
1018
1019static const struct rpc_filelist authfiles[] = {
1020 [RPCAUTH_info] = {
1021 .name = "info",
1022 .i_fop = &rpc_info_operations,
1023 .mode = S_IFREG | 0400,
1024 },
1025};
1026
1027static int rpc_clntdir_populate(struct dentry *dentry, void *private)
1028{
1029 return rpc_populate(dentry,
1030 authfiles, RPCAUTH_info, RPCAUTH_EOF,
1031 private);
1032}
1033
1034static void rpc_clntdir_depopulate(struct dentry *dentry)
1035{
1036 rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
1037}
1038
1039/**
1040 * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
1041 * @dentry: the parent of new directory
1042 * @name: the name of new directory
1043 * @rpc_client: rpc client to associate with this directory
1044 *
1045 * This creates a directory at the given @path associated with
1046 * @rpc_clnt, which will contain a file named "info" with some basic
1047 * information about the client, together with any "pipes" that may
1048 * later be created using rpc_mkpipe().
1049 */
1050struct dentry *rpc_create_client_dir(struct dentry *dentry,
1051 const char *name,
1052 struct rpc_clnt *rpc_client)
1053{
1054 struct dentry *ret;
1055
1056 ret = rpc_mkdir_populate(dentry, name, 0555, NULL,
1057 rpc_clntdir_populate, rpc_client);
1058 if (!IS_ERR(ret)) {
1059 rpc_client->cl_pipedir_objects.pdh_dentry = ret;
1060 rpc_create_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1061 }
1062 return ret;
1063}
1064
1065/**
1066 * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
1067 * @rpc_client: rpc_client for the pipe
1068 */
1069int rpc_remove_client_dir(struct rpc_clnt *rpc_client)
1070{
1071 struct dentry *dentry = rpc_client->cl_pipedir_objects.pdh_dentry;
1072
1073 if (dentry == NULL)
1074 return 0;
1075 rpc_destroy_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1076 rpc_client->cl_pipedir_objects.pdh_dentry = NULL;
1077 return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
1078}
1079
1080static const struct rpc_filelist cache_pipefs_files[3] = {
1081 [0] = {
1082 .name = "channel",
1083 .i_fop = &cache_file_operations_pipefs,
1084 .mode = S_IFREG | 0600,
1085 },
1086 [1] = {
1087 .name = "content",
1088 .i_fop = &content_file_operations_pipefs,
1089 .mode = S_IFREG | 0400,
1090 },
1091 [2] = {
1092 .name = "flush",
1093 .i_fop = &cache_flush_operations_pipefs,
1094 .mode = S_IFREG | 0600,
1095 },
1096};
1097
1098static int rpc_cachedir_populate(struct dentry *dentry, void *private)
1099{
1100 return rpc_populate(dentry,
1101 cache_pipefs_files, 0, 3,
1102 private);
1103}
1104
1105static void rpc_cachedir_depopulate(struct dentry *dentry)
1106{
1107 rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
1108}
1109
1110struct dentry *rpc_create_cache_dir(struct dentry *parent, const char *name,
1111 umode_t umode, struct cache_detail *cd)
1112{
1113 return rpc_mkdir_populate(parent, name, umode, NULL,
1114 rpc_cachedir_populate, cd);
1115}
1116
1117void rpc_remove_cache_dir(struct dentry *dentry)
1118{
1119 rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
1120}
1121
1122/*
1123 * populate the filesystem
1124 */
1125static const struct super_operations s_ops = {
1126 .alloc_inode = rpc_alloc_inode,
1127 .free_inode = rpc_free_inode,
1128 .statfs = simple_statfs,
1129};
1130
1131#define RPCAUTH_GSSMAGIC 0x67596969
1132
1133/*
1134 * We have a single directory with 1 node in it.
1135 */
1136enum {
1137 RPCAUTH_lockd,
1138 RPCAUTH_mount,
1139 RPCAUTH_nfs,
1140 RPCAUTH_portmap,
1141 RPCAUTH_statd,
1142 RPCAUTH_nfsd4_cb,
1143 RPCAUTH_cache,
1144 RPCAUTH_nfsd,
1145 RPCAUTH_gssd,
1146 RPCAUTH_RootEOF
1147};
1148
1149static const struct rpc_filelist files[] = {
1150 [RPCAUTH_lockd] = {
1151 .name = "lockd",
1152 .mode = S_IFDIR | 0555,
1153 },
1154 [RPCAUTH_mount] = {
1155 .name = "mount",
1156 .mode = S_IFDIR | 0555,
1157 },
1158 [RPCAUTH_nfs] = {
1159 .name = "nfs",
1160 .mode = S_IFDIR | 0555,
1161 },
1162 [RPCAUTH_portmap] = {
1163 .name = "portmap",
1164 .mode = S_IFDIR | 0555,
1165 },
1166 [RPCAUTH_statd] = {
1167 .name = "statd",
1168 .mode = S_IFDIR | 0555,
1169 },
1170 [RPCAUTH_nfsd4_cb] = {
1171 .name = "nfsd4_cb",
1172 .mode = S_IFDIR | 0555,
1173 },
1174 [RPCAUTH_cache] = {
1175 .name = "cache",
1176 .mode = S_IFDIR | 0555,
1177 },
1178 [RPCAUTH_nfsd] = {
1179 .name = "nfsd",
1180 .mode = S_IFDIR | 0555,
1181 },
1182 [RPCAUTH_gssd] = {
1183 .name = "gssd",
1184 .mode = S_IFDIR | 0555,
1185 },
1186};
1187
1188/*
1189 * This call can be used only in RPC pipefs mount notification hooks.
1190 */
1191struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
1192 const unsigned char *dir_name)
1193{
1194 struct qstr dir = QSTR_INIT(dir_name, strlen(dir_name));
1195 return d_hash_and_lookup(sb->s_root, &dir);
1196}
1197EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
1198
1199int rpc_pipefs_init_net(struct net *net)
1200{
1201 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1202
1203 sn->gssd_dummy = rpc_mkpipe_data(&gssd_dummy_pipe_ops, 0);
1204 if (IS_ERR(sn->gssd_dummy))
1205 return PTR_ERR(sn->gssd_dummy);
1206
1207 mutex_init(&sn->pipefs_sb_lock);
1208 sn->pipe_version = -1;
1209 return 0;
1210}
1211
1212void rpc_pipefs_exit_net(struct net *net)
1213{
1214 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1215
1216 rpc_destroy_pipe_data(sn->gssd_dummy);
1217}
1218
1219/*
1220 * This call will be used for per network namespace operations calls.
1221 * Note: Function will be returned with pipefs_sb_lock taken if superblock was
1222 * found. This lock have to be released by rpc_put_sb_net() when all operations
1223 * will be completed.
1224 */
1225struct super_block *rpc_get_sb_net(const struct net *net)
1226{
1227 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1228
1229 mutex_lock(&sn->pipefs_sb_lock);
1230 if (sn->pipefs_sb)
1231 return sn->pipefs_sb;
1232 mutex_unlock(&sn->pipefs_sb_lock);
1233 return NULL;
1234}
1235EXPORT_SYMBOL_GPL(rpc_get_sb_net);
1236
1237void rpc_put_sb_net(const struct net *net)
1238{
1239 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1240
1241 WARN_ON(sn->pipefs_sb == NULL);
1242 mutex_unlock(&sn->pipefs_sb_lock);
1243}
1244EXPORT_SYMBOL_GPL(rpc_put_sb_net);
1245
1246static const struct rpc_filelist gssd_dummy_clnt_dir[] = {
1247 [0] = {
1248 .name = "clntXX",
1249 .mode = S_IFDIR | 0555,
1250 },
1251};
1252
1253static ssize_t
1254dummy_downcall(struct file *filp, const char __user *src, size_t len)
1255{
1256 return -EINVAL;
1257}
1258
1259static const struct rpc_pipe_ops gssd_dummy_pipe_ops = {
1260 .upcall = rpc_pipe_generic_upcall,
1261 .downcall = dummy_downcall,
1262};
1263
1264/*
1265 * Here we present a bogus "info" file to keep rpc.gssd happy. We don't expect
1266 * that it will ever use this info to handle an upcall, but rpc.gssd expects
1267 * that this file will be there and have a certain format.
1268 */
1269static int
1270rpc_dummy_info_show(struct seq_file *m, void *v)
1271{
1272 seq_printf(m, "RPC server: %s\n", utsname()->nodename);
1273 seq_printf(m, "service: foo (1) version 0\n");
1274 seq_printf(m, "address: 127.0.0.1\n");
1275 seq_printf(m, "protocol: tcp\n");
1276 seq_printf(m, "port: 0\n");
1277 return 0;
1278}
1279DEFINE_SHOW_ATTRIBUTE(rpc_dummy_info);
1280
1281static const struct rpc_filelist gssd_dummy_info_file[] = {
1282 [0] = {
1283 .name = "info",
1284 .i_fop = &rpc_dummy_info_fops,
1285 .mode = S_IFREG | 0400,
1286 },
1287};
1288
1289/**
1290 * rpc_gssd_dummy_populate - create a dummy gssd pipe
1291 * @root: root of the rpc_pipefs filesystem
1292 * @pipe_data: pipe data created when netns is initialized
1293 *
1294 * Create a dummy set of directories and a pipe that gssd can hold open to
1295 * indicate that it is up and running.
1296 */
1297static struct dentry *
1298rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data)
1299{
1300 int ret = 0;
1301 struct dentry *gssd_dentry;
1302 struct dentry *clnt_dentry = NULL;
1303 struct dentry *pipe_dentry = NULL;
1304 struct qstr q = QSTR_INIT(files[RPCAUTH_gssd].name,
1305 strlen(files[RPCAUTH_gssd].name));
1306
1307 /* We should never get this far if "gssd" doesn't exist */
1308 gssd_dentry = d_hash_and_lookup(root, &q);
1309 if (!gssd_dentry)
1310 return ERR_PTR(-ENOENT);
1311
1312 ret = rpc_populate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1, NULL);
1313 if (ret) {
1314 pipe_dentry = ERR_PTR(ret);
1315 goto out;
1316 }
1317
1318 q.name = gssd_dummy_clnt_dir[0].name;
1319 q.len = strlen(gssd_dummy_clnt_dir[0].name);
1320 clnt_dentry = d_hash_and_lookup(gssd_dentry, &q);
1321 if (!clnt_dentry) {
1322 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1323 pipe_dentry = ERR_PTR(-ENOENT);
1324 goto out;
1325 }
1326
1327 ret = rpc_populate(clnt_dentry, gssd_dummy_info_file, 0, 1, NULL);
1328 if (ret) {
1329 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1330 pipe_dentry = ERR_PTR(ret);
1331 goto out;
1332 }
1333
1334 pipe_dentry = rpc_mkpipe_dentry(clnt_dentry, "gssd", NULL, pipe_data);
1335 if (IS_ERR(pipe_dentry)) {
1336 __rpc_depopulate(clnt_dentry, gssd_dummy_info_file, 0, 1);
1337 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1338 }
1339out:
1340 dput(clnt_dentry);
1341 dput(gssd_dentry);
1342 return pipe_dentry;
1343}
1344
1345static void
1346rpc_gssd_dummy_depopulate(struct dentry *pipe_dentry)
1347{
1348 struct dentry *clnt_dir = pipe_dentry->d_parent;
1349 struct dentry *gssd_dir = clnt_dir->d_parent;
1350
1351 dget(pipe_dentry);
1352 __rpc_rmpipe(d_inode(clnt_dir), pipe_dentry);
1353 __rpc_depopulate(clnt_dir, gssd_dummy_info_file, 0, 1);
1354 __rpc_depopulate(gssd_dir, gssd_dummy_clnt_dir, 0, 1);
1355 dput(pipe_dentry);
1356}
1357
1358static int
1359rpc_fill_super(struct super_block *sb, struct fs_context *fc)
1360{
1361 struct inode *inode;
1362 struct dentry *root, *gssd_dentry;
1363 struct net *net = sb->s_fs_info;
1364 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1365 int err;
1366
1367 sb->s_blocksize = PAGE_SIZE;
1368 sb->s_blocksize_bits = PAGE_SHIFT;
1369 sb->s_magic = RPCAUTH_GSSMAGIC;
1370 sb->s_op = &s_ops;
1371 sb->s_d_op = &simple_dentry_operations;
1372 sb->s_time_gran = 1;
1373
1374 inode = rpc_get_inode(sb, S_IFDIR | 0555);
1375 sb->s_root = root = d_make_root(inode);
1376 if (!root)
1377 return -ENOMEM;
1378 if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
1379 return -ENOMEM;
1380
1381 gssd_dentry = rpc_gssd_dummy_populate(root, sn->gssd_dummy);
1382 if (IS_ERR(gssd_dentry)) {
1383 __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1384 return PTR_ERR(gssd_dentry);
1385 }
1386
1387 dprintk("RPC: sending pipefs MOUNT notification for net %x%s\n",
1388 net->ns.inum, NET_NAME(net));
1389 mutex_lock(&sn->pipefs_sb_lock);
1390 sn->pipefs_sb = sb;
1391 err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1392 RPC_PIPEFS_MOUNT,
1393 sb);
1394 if (err)
1395 goto err_depopulate;
1396 mutex_unlock(&sn->pipefs_sb_lock);
1397 return 0;
1398
1399err_depopulate:
1400 rpc_gssd_dummy_depopulate(gssd_dentry);
1401 blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1402 RPC_PIPEFS_UMOUNT,
1403 sb);
1404 sn->pipefs_sb = NULL;
1405 __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1406 mutex_unlock(&sn->pipefs_sb_lock);
1407 return err;
1408}
1409
1410bool
1411gssd_running(struct net *net)
1412{
1413 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1414 struct rpc_pipe *pipe = sn->gssd_dummy;
1415
1416 return pipe->nreaders || pipe->nwriters;
1417}
1418EXPORT_SYMBOL_GPL(gssd_running);
1419
1420static int rpc_fs_get_tree(struct fs_context *fc)
1421{
1422 return get_tree_keyed(fc, rpc_fill_super, get_net(fc->net_ns));
1423}
1424
1425static void rpc_fs_free_fc(struct fs_context *fc)
1426{
1427 if (fc->s_fs_info)
1428 put_net(fc->s_fs_info);
1429}
1430
1431static const struct fs_context_operations rpc_fs_context_ops = {
1432 .free = rpc_fs_free_fc,
1433 .get_tree = rpc_fs_get_tree,
1434};
1435
1436static int rpc_init_fs_context(struct fs_context *fc)
1437{
1438 put_user_ns(fc->user_ns);
1439 fc->user_ns = get_user_ns(fc->net_ns->user_ns);
1440 fc->ops = &rpc_fs_context_ops;
1441 return 0;
1442}
1443
1444static void rpc_kill_sb(struct super_block *sb)
1445{
1446 struct net *net = sb->s_fs_info;
1447 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1448
1449 mutex_lock(&sn->pipefs_sb_lock);
1450 if (sn->pipefs_sb != sb) {
1451 mutex_unlock(&sn->pipefs_sb_lock);
1452 goto out;
1453 }
1454 sn->pipefs_sb = NULL;
1455 dprintk("RPC: sending pipefs UMOUNT notification for net %x%s\n",
1456 net->ns.inum, NET_NAME(net));
1457 blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1458 RPC_PIPEFS_UMOUNT,
1459 sb);
1460 mutex_unlock(&sn->pipefs_sb_lock);
1461out:
1462 kill_litter_super(sb);
1463 put_net(net);
1464}
1465
1466static struct file_system_type rpc_pipe_fs_type = {
1467 .owner = THIS_MODULE,
1468 .name = "rpc_pipefs",
1469 .init_fs_context = rpc_init_fs_context,
1470 .kill_sb = rpc_kill_sb,
1471};
1472MODULE_ALIAS_FS("rpc_pipefs");
1473MODULE_ALIAS("rpc_pipefs");
1474
1475static void
1476init_once(void *foo)
1477{
1478 struct rpc_inode *rpci = (struct rpc_inode *) foo;
1479
1480 inode_init_once(&rpci->vfs_inode);
1481 rpci->private = NULL;
1482 rpci->pipe = NULL;
1483 init_waitqueue_head(&rpci->waitq);
1484}
1485
1486int register_rpc_pipefs(void)
1487{
1488 int err;
1489
1490 rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1491 sizeof(struct rpc_inode),
1492 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1493 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1494 init_once);
1495 if (!rpc_inode_cachep)
1496 return -ENOMEM;
1497 err = rpc_clients_notifier_register();
1498 if (err)
1499 goto err_notifier;
1500 err = register_filesystem(&rpc_pipe_fs_type);
1501 if (err)
1502 goto err_register;
1503 return 0;
1504
1505err_register:
1506 rpc_clients_notifier_unregister();
1507err_notifier:
1508 kmem_cache_destroy(rpc_inode_cachep);
1509 return err;
1510}
1511
1512void unregister_rpc_pipefs(void)
1513{
1514 rpc_clients_notifier_unregister();
1515 unregister_filesystem(&rpc_pipe_fs_type);
1516 kmem_cache_destroy(rpc_inode_cachep);
1517}
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
20#include <asm/ioctls.h>
21#include <linux/fs.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
31static struct vfsmount *rpc_mnt __read_mostly;
32static int rpc_mount_count;
33
34static struct file_system_type rpc_pipe_fs_type;
35
36
37static struct kmem_cache *rpc_inode_cachep __read_mostly;
38
39#define RPC_UPCALL_TIMEOUT (30*HZ)
40
41static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head,
42 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
43{
44 struct rpc_pipe_msg *msg;
45
46 if (list_empty(head))
47 return;
48 do {
49 msg = list_entry(head->next, struct rpc_pipe_msg, list);
50 list_del_init(&msg->list);
51 msg->errno = err;
52 destroy_msg(msg);
53 } while (!list_empty(head));
54 wake_up(&rpci->waitq);
55}
56
57static void
58rpc_timeout_upcall_queue(struct work_struct *work)
59{
60 LIST_HEAD(free_list);
61 struct rpc_inode *rpci =
62 container_of(work, struct rpc_inode, queue_timeout.work);
63 struct inode *inode = &rpci->vfs_inode;
64 void (*destroy_msg)(struct rpc_pipe_msg *);
65
66 spin_lock(&inode->i_lock);
67 if (rpci->ops == NULL) {
68 spin_unlock(&inode->i_lock);
69 return;
70 }
71 destroy_msg = rpci->ops->destroy_msg;
72 if (rpci->nreaders == 0) {
73 list_splice_init(&rpci->pipe, &free_list);
74 rpci->pipelen = 0;
75 }
76 spin_unlock(&inode->i_lock);
77 rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
78}
79
80/**
81 * rpc_queue_upcall - queue an upcall message to userspace
82 * @inode: inode of upcall pipe on which to queue given message
83 * @msg: message to queue
84 *
85 * Call with an @inode created by rpc_mkpipe() to queue an upcall.
86 * A userspace process may then later read the upcall by performing a
87 * read on an open file for this inode. It is up to the caller to
88 * initialize the fields of @msg (other than @msg->list) appropriately.
89 */
90int
91rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
92{
93 struct rpc_inode *rpci = RPC_I(inode);
94 int res = -EPIPE;
95
96 spin_lock(&inode->i_lock);
97 if (rpci->ops == NULL)
98 goto out;
99 if (rpci->nreaders) {
100 list_add_tail(&msg->list, &rpci->pipe);
101 rpci->pipelen += msg->len;
102 res = 0;
103 } else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) {
104 if (list_empty(&rpci->pipe))
105 queue_delayed_work(rpciod_workqueue,
106 &rpci->queue_timeout,
107 RPC_UPCALL_TIMEOUT);
108 list_add_tail(&msg->list, &rpci->pipe);
109 rpci->pipelen += msg->len;
110 res = 0;
111 }
112out:
113 spin_unlock(&inode->i_lock);
114 wake_up(&rpci->waitq);
115 return res;
116}
117EXPORT_SYMBOL_GPL(rpc_queue_upcall);
118
119static inline void
120rpc_inode_setowner(struct inode *inode, void *private)
121{
122 RPC_I(inode)->private = private;
123}
124
125static void
126rpc_close_pipes(struct inode *inode)
127{
128 struct rpc_inode *rpci = RPC_I(inode);
129 const struct rpc_pipe_ops *ops;
130 int need_release;
131
132 mutex_lock(&inode->i_mutex);
133 ops = rpci->ops;
134 if (ops != NULL) {
135 LIST_HEAD(free_list);
136 spin_lock(&inode->i_lock);
137 need_release = rpci->nreaders != 0 || rpci->nwriters != 0;
138 rpci->nreaders = 0;
139 list_splice_init(&rpci->in_upcall, &free_list);
140 list_splice_init(&rpci->pipe, &free_list);
141 rpci->pipelen = 0;
142 rpci->ops = NULL;
143 spin_unlock(&inode->i_lock);
144 rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE);
145 rpci->nwriters = 0;
146 if (need_release && ops->release_pipe)
147 ops->release_pipe(inode);
148 cancel_delayed_work_sync(&rpci->queue_timeout);
149 }
150 rpc_inode_setowner(inode, NULL);
151 mutex_unlock(&inode->i_mutex);
152}
153
154static struct inode *
155rpc_alloc_inode(struct super_block *sb)
156{
157 struct rpc_inode *rpci;
158 rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
159 if (!rpci)
160 return NULL;
161 return &rpci->vfs_inode;
162}
163
164static void
165rpc_i_callback(struct rcu_head *head)
166{
167 struct inode *inode = container_of(head, struct inode, i_rcu);
168 INIT_LIST_HEAD(&inode->i_dentry);
169 kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
170}
171
172static void
173rpc_destroy_inode(struct inode *inode)
174{
175 call_rcu(&inode->i_rcu, rpc_i_callback);
176}
177
178static int
179rpc_pipe_open(struct inode *inode, struct file *filp)
180{
181 struct rpc_inode *rpci = RPC_I(inode);
182 int first_open;
183 int res = -ENXIO;
184
185 mutex_lock(&inode->i_mutex);
186 if (rpci->ops == NULL)
187 goto out;
188 first_open = rpci->nreaders == 0 && rpci->nwriters == 0;
189 if (first_open && rpci->ops->open_pipe) {
190 res = rpci->ops->open_pipe(inode);
191 if (res)
192 goto out;
193 }
194 if (filp->f_mode & FMODE_READ)
195 rpci->nreaders++;
196 if (filp->f_mode & FMODE_WRITE)
197 rpci->nwriters++;
198 res = 0;
199out:
200 mutex_unlock(&inode->i_mutex);
201 return res;
202}
203
204static int
205rpc_pipe_release(struct inode *inode, struct file *filp)
206{
207 struct rpc_inode *rpci = RPC_I(inode);
208 struct rpc_pipe_msg *msg;
209 int last_close;
210
211 mutex_lock(&inode->i_mutex);
212 if (rpci->ops == NULL)
213 goto out;
214 msg = filp->private_data;
215 if (msg != NULL) {
216 spin_lock(&inode->i_lock);
217 msg->errno = -EAGAIN;
218 list_del_init(&msg->list);
219 spin_unlock(&inode->i_lock);
220 rpci->ops->destroy_msg(msg);
221 }
222 if (filp->f_mode & FMODE_WRITE)
223 rpci->nwriters --;
224 if (filp->f_mode & FMODE_READ) {
225 rpci->nreaders --;
226 if (rpci->nreaders == 0) {
227 LIST_HEAD(free_list);
228 spin_lock(&inode->i_lock);
229 list_splice_init(&rpci->pipe, &free_list);
230 rpci->pipelen = 0;
231 spin_unlock(&inode->i_lock);
232 rpc_purge_list(rpci, &free_list,
233 rpci->ops->destroy_msg, -EAGAIN);
234 }
235 }
236 last_close = rpci->nwriters == 0 && rpci->nreaders == 0;
237 if (last_close && rpci->ops->release_pipe)
238 rpci->ops->release_pipe(inode);
239out:
240 mutex_unlock(&inode->i_mutex);
241 return 0;
242}
243
244static ssize_t
245rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
246{
247 struct inode *inode = filp->f_path.dentry->d_inode;
248 struct rpc_inode *rpci = RPC_I(inode);
249 struct rpc_pipe_msg *msg;
250 int res = 0;
251
252 mutex_lock(&inode->i_mutex);
253 if (rpci->ops == NULL) {
254 res = -EPIPE;
255 goto out_unlock;
256 }
257 msg = filp->private_data;
258 if (msg == NULL) {
259 spin_lock(&inode->i_lock);
260 if (!list_empty(&rpci->pipe)) {
261 msg = list_entry(rpci->pipe.next,
262 struct rpc_pipe_msg,
263 list);
264 list_move(&msg->list, &rpci->in_upcall);
265 rpci->pipelen -= msg->len;
266 filp->private_data = msg;
267 msg->copied = 0;
268 }
269 spin_unlock(&inode->i_lock);
270 if (msg == NULL)
271 goto out_unlock;
272 }
273 /* NOTE: it is up to the callback to update msg->copied */
274 res = rpci->ops->upcall(filp, msg, buf, len);
275 if (res < 0 || msg->len == msg->copied) {
276 filp->private_data = NULL;
277 spin_lock(&inode->i_lock);
278 list_del_init(&msg->list);
279 spin_unlock(&inode->i_lock);
280 rpci->ops->destroy_msg(msg);
281 }
282out_unlock:
283 mutex_unlock(&inode->i_mutex);
284 return res;
285}
286
287static ssize_t
288rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
289{
290 struct inode *inode = filp->f_path.dentry->d_inode;
291 struct rpc_inode *rpci = RPC_I(inode);
292 int res;
293
294 mutex_lock(&inode->i_mutex);
295 res = -EPIPE;
296 if (rpci->ops != NULL)
297 res = rpci->ops->downcall(filp, buf, len);
298 mutex_unlock(&inode->i_mutex);
299 return res;
300}
301
302static unsigned int
303rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
304{
305 struct rpc_inode *rpci;
306 unsigned int mask = 0;
307
308 rpci = RPC_I(filp->f_path.dentry->d_inode);
309 poll_wait(filp, &rpci->waitq, wait);
310
311 mask = POLLOUT | POLLWRNORM;
312 if (rpci->ops == NULL)
313 mask |= POLLERR | POLLHUP;
314 if (filp->private_data || !list_empty(&rpci->pipe))
315 mask |= POLLIN | POLLRDNORM;
316 return mask;
317}
318
319static long
320rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
321{
322 struct inode *inode = filp->f_path.dentry->d_inode;
323 struct rpc_inode *rpci = RPC_I(inode);
324 int len;
325
326 switch (cmd) {
327 case FIONREAD:
328 spin_lock(&inode->i_lock);
329 if (rpci->ops == NULL) {
330 spin_unlock(&inode->i_lock);
331 return -EPIPE;
332 }
333 len = rpci->pipelen;
334 if (filp->private_data) {
335 struct rpc_pipe_msg *msg;
336 msg = filp->private_data;
337 len += msg->len - msg->copied;
338 }
339 spin_unlock(&inode->i_lock);
340 return put_user(len, (int __user *)arg);
341 default:
342 return -EINVAL;
343 }
344}
345
346static const struct file_operations rpc_pipe_fops = {
347 .owner = THIS_MODULE,
348 .llseek = no_llseek,
349 .read = rpc_pipe_read,
350 .write = rpc_pipe_write,
351 .poll = rpc_pipe_poll,
352 .unlocked_ioctl = rpc_pipe_ioctl,
353 .open = rpc_pipe_open,
354 .release = rpc_pipe_release,
355};
356
357static int
358rpc_show_info(struct seq_file *m, void *v)
359{
360 struct rpc_clnt *clnt = m->private;
361
362 seq_printf(m, "RPC server: %s\n", clnt->cl_server);
363 seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
364 clnt->cl_prog, clnt->cl_vers);
365 seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
366 seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
367 seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
368 return 0;
369}
370
371static int
372rpc_info_open(struct inode *inode, struct file *file)
373{
374 struct rpc_clnt *clnt = NULL;
375 int ret = single_open(file, rpc_show_info, NULL);
376
377 if (!ret) {
378 struct seq_file *m = file->private_data;
379
380 spin_lock(&file->f_path.dentry->d_lock);
381 if (!d_unhashed(file->f_path.dentry))
382 clnt = RPC_I(inode)->private;
383 if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) {
384 spin_unlock(&file->f_path.dentry->d_lock);
385 m->private = clnt;
386 } else {
387 spin_unlock(&file->f_path.dentry->d_lock);
388 single_release(inode, file);
389 ret = -EINVAL;
390 }
391 }
392 return ret;
393}
394
395static int
396rpc_info_release(struct inode *inode, struct file *file)
397{
398 struct seq_file *m = file->private_data;
399 struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
400
401 if (clnt)
402 rpc_release_client(clnt);
403 return single_release(inode, file);
404}
405
406static const struct file_operations rpc_info_operations = {
407 .owner = THIS_MODULE,
408 .open = rpc_info_open,
409 .read = seq_read,
410 .llseek = seq_lseek,
411 .release = rpc_info_release,
412};
413
414
415/*
416 * Description of fs contents.
417 */
418struct rpc_filelist {
419 const char *name;
420 const struct file_operations *i_fop;
421 umode_t mode;
422};
423
424struct vfsmount *rpc_get_mount(void)
425{
426 int err;
427
428 err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mnt, &rpc_mount_count);
429 if (err != 0)
430 return ERR_PTR(err);
431 return rpc_mnt;
432}
433EXPORT_SYMBOL_GPL(rpc_get_mount);
434
435void rpc_put_mount(void)
436{
437 simple_release_fs(&rpc_mnt, &rpc_mount_count);
438}
439EXPORT_SYMBOL_GPL(rpc_put_mount);
440
441static int rpc_delete_dentry(const struct dentry *dentry)
442{
443 return 1;
444}
445
446static const struct dentry_operations rpc_dentry_operations = {
447 .d_delete = rpc_delete_dentry,
448};
449
450static struct inode *
451rpc_get_inode(struct super_block *sb, umode_t mode)
452{
453 struct inode *inode = new_inode(sb);
454 if (!inode)
455 return NULL;
456 inode->i_ino = get_next_ino();
457 inode->i_mode = mode;
458 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
459 switch (mode & S_IFMT) {
460 case S_IFDIR:
461 inode->i_fop = &simple_dir_operations;
462 inode->i_op = &simple_dir_inode_operations;
463 inc_nlink(inode);
464 default:
465 break;
466 }
467 return inode;
468}
469
470static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
471 umode_t mode,
472 const struct file_operations *i_fop,
473 void *private)
474{
475 struct inode *inode;
476
477 d_drop(dentry);
478 inode = rpc_get_inode(dir->i_sb, mode);
479 if (!inode)
480 goto out_err;
481 inode->i_ino = iunique(dir->i_sb, 100);
482 if (i_fop)
483 inode->i_fop = i_fop;
484 if (private)
485 rpc_inode_setowner(inode, private);
486 d_add(dentry, inode);
487 return 0;
488out_err:
489 printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
490 __FILE__, __func__, dentry->d_name.name);
491 dput(dentry);
492 return -ENOMEM;
493}
494
495static int __rpc_create(struct inode *dir, struct dentry *dentry,
496 umode_t mode,
497 const struct file_operations *i_fop,
498 void *private)
499{
500 int err;
501
502 err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
503 if (err)
504 return err;
505 fsnotify_create(dir, dentry);
506 return 0;
507}
508
509static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
510 umode_t mode,
511 const struct file_operations *i_fop,
512 void *private)
513{
514 int err;
515
516 err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
517 if (err)
518 return err;
519 inc_nlink(dir);
520 fsnotify_mkdir(dir, dentry);
521 return 0;
522}
523
524static int __rpc_mkpipe(struct inode *dir, struct dentry *dentry,
525 umode_t mode,
526 const struct file_operations *i_fop,
527 void *private,
528 const struct rpc_pipe_ops *ops,
529 int flags)
530{
531 struct rpc_inode *rpci;
532 int err;
533
534 err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
535 if (err)
536 return err;
537 rpci = RPC_I(dentry->d_inode);
538 rpci->nkern_readwriters = 1;
539 rpci->private = private;
540 rpci->flags = flags;
541 rpci->ops = ops;
542 fsnotify_create(dir, dentry);
543 return 0;
544}
545
546static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
547{
548 int ret;
549
550 dget(dentry);
551 ret = simple_rmdir(dir, dentry);
552 d_delete(dentry);
553 dput(dentry);
554 return ret;
555}
556
557static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
558{
559 int ret;
560
561 dget(dentry);
562 ret = simple_unlink(dir, dentry);
563 d_delete(dentry);
564 dput(dentry);
565 return ret;
566}
567
568static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
569{
570 struct inode *inode = dentry->d_inode;
571 struct rpc_inode *rpci = RPC_I(inode);
572
573 rpci->nkern_readwriters--;
574 if (rpci->nkern_readwriters != 0)
575 return 0;
576 rpc_close_pipes(inode);
577 return __rpc_unlink(dir, dentry);
578}
579
580static struct dentry *__rpc_lookup_create(struct dentry *parent,
581 struct qstr *name)
582{
583 struct dentry *dentry;
584
585 dentry = d_lookup(parent, name);
586 if (!dentry) {
587 dentry = d_alloc(parent, name);
588 if (!dentry) {
589 dentry = ERR_PTR(-ENOMEM);
590 goto out_err;
591 }
592 }
593 if (!dentry->d_inode)
594 d_set_d_op(dentry, &rpc_dentry_operations);
595out_err:
596 return dentry;
597}
598
599static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
600 struct qstr *name)
601{
602 struct dentry *dentry;
603
604 dentry = __rpc_lookup_create(parent, name);
605 if (IS_ERR(dentry))
606 return dentry;
607 if (dentry->d_inode == NULL)
608 return dentry;
609 dput(dentry);
610 return ERR_PTR(-EEXIST);
611}
612
613/*
614 * FIXME: This probably has races.
615 */
616static void __rpc_depopulate(struct dentry *parent,
617 const struct rpc_filelist *files,
618 int start, int eof)
619{
620 struct inode *dir = parent->d_inode;
621 struct dentry *dentry;
622 struct qstr name;
623 int i;
624
625 for (i = start; i < eof; i++) {
626 name.name = files[i].name;
627 name.len = strlen(files[i].name);
628 name.hash = full_name_hash(name.name, name.len);
629 dentry = d_lookup(parent, &name);
630
631 if (dentry == NULL)
632 continue;
633 if (dentry->d_inode == NULL)
634 goto next;
635 switch (dentry->d_inode->i_mode & S_IFMT) {
636 default:
637 BUG();
638 case S_IFREG:
639 __rpc_unlink(dir, dentry);
640 break;
641 case S_IFDIR:
642 __rpc_rmdir(dir, dentry);
643 }
644next:
645 dput(dentry);
646 }
647}
648
649static void rpc_depopulate(struct dentry *parent,
650 const struct rpc_filelist *files,
651 int start, int eof)
652{
653 struct inode *dir = parent->d_inode;
654
655 mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
656 __rpc_depopulate(parent, files, start, eof);
657 mutex_unlock(&dir->i_mutex);
658}
659
660static int rpc_populate(struct dentry *parent,
661 const struct rpc_filelist *files,
662 int start, int eof,
663 void *private)
664{
665 struct inode *dir = parent->d_inode;
666 struct dentry *dentry;
667 int i, err;
668
669 mutex_lock(&dir->i_mutex);
670 for (i = start; i < eof; i++) {
671 struct qstr q;
672
673 q.name = files[i].name;
674 q.len = strlen(files[i].name);
675 q.hash = full_name_hash(q.name, q.len);
676 dentry = __rpc_lookup_create_exclusive(parent, &q);
677 err = PTR_ERR(dentry);
678 if (IS_ERR(dentry))
679 goto out_bad;
680 switch (files[i].mode & S_IFMT) {
681 default:
682 BUG();
683 case S_IFREG:
684 err = __rpc_create(dir, dentry,
685 files[i].mode,
686 files[i].i_fop,
687 private);
688 break;
689 case S_IFDIR:
690 err = __rpc_mkdir(dir, dentry,
691 files[i].mode,
692 NULL,
693 private);
694 }
695 if (err != 0)
696 goto out_bad;
697 }
698 mutex_unlock(&dir->i_mutex);
699 return 0;
700out_bad:
701 __rpc_depopulate(parent, files, start, eof);
702 mutex_unlock(&dir->i_mutex);
703 printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
704 __FILE__, __func__, parent->d_name.name);
705 return err;
706}
707
708static struct dentry *rpc_mkdir_populate(struct dentry *parent,
709 struct qstr *name, umode_t mode, void *private,
710 int (*populate)(struct dentry *, void *), void *args_populate)
711{
712 struct dentry *dentry;
713 struct inode *dir = parent->d_inode;
714 int error;
715
716 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
717 dentry = __rpc_lookup_create_exclusive(parent, name);
718 if (IS_ERR(dentry))
719 goto out;
720 error = __rpc_mkdir(dir, dentry, mode, NULL, private);
721 if (error != 0)
722 goto out_err;
723 if (populate != NULL) {
724 error = populate(dentry, args_populate);
725 if (error)
726 goto err_rmdir;
727 }
728out:
729 mutex_unlock(&dir->i_mutex);
730 return dentry;
731err_rmdir:
732 __rpc_rmdir(dir, dentry);
733out_err:
734 dentry = ERR_PTR(error);
735 goto out;
736}
737
738static int rpc_rmdir_depopulate(struct dentry *dentry,
739 void (*depopulate)(struct dentry *))
740{
741 struct dentry *parent;
742 struct inode *dir;
743 int error;
744
745 parent = dget_parent(dentry);
746 dir = parent->d_inode;
747 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
748 if (depopulate != NULL)
749 depopulate(dentry);
750 error = __rpc_rmdir(dir, dentry);
751 mutex_unlock(&dir->i_mutex);
752 dput(parent);
753 return error;
754}
755
756/**
757 * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
758 * @parent: dentry of directory to create new "pipe" in
759 * @name: name of pipe
760 * @private: private data to associate with the pipe, for the caller's use
761 * @ops: operations defining the behavior of the pipe: upcall, downcall,
762 * release_pipe, open_pipe, and destroy_msg.
763 * @flags: rpc_inode flags
764 *
765 * Data is made available for userspace to read by calls to
766 * rpc_queue_upcall(). The actual reads will result in calls to
767 * @ops->upcall, which will be called with the file pointer,
768 * message, and userspace buffer to copy to.
769 *
770 * Writes can come at any time, and do not necessarily have to be
771 * responses to upcalls. They will result in calls to @msg->downcall.
772 *
773 * The @private argument passed here will be available to all these methods
774 * from the file pointer, via RPC_I(file->f_dentry->d_inode)->private.
775 */
776struct dentry *rpc_mkpipe(struct dentry *parent, const char *name,
777 void *private, const struct rpc_pipe_ops *ops,
778 int flags)
779{
780 struct dentry *dentry;
781 struct inode *dir = parent->d_inode;
782 umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR;
783 struct qstr q;
784 int err;
785
786 if (ops->upcall == NULL)
787 umode &= ~S_IRUGO;
788 if (ops->downcall == NULL)
789 umode &= ~S_IWUGO;
790
791 q.name = name;
792 q.len = strlen(name);
793 q.hash = full_name_hash(q.name, q.len),
794
795 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
796 dentry = __rpc_lookup_create(parent, &q);
797 if (IS_ERR(dentry))
798 goto out;
799 if (dentry->d_inode) {
800 struct rpc_inode *rpci = RPC_I(dentry->d_inode);
801 if (rpci->private != private ||
802 rpci->ops != ops ||
803 rpci->flags != flags) {
804 dput (dentry);
805 err = -EBUSY;
806 goto out_err;
807 }
808 rpci->nkern_readwriters++;
809 goto out;
810 }
811
812 err = __rpc_mkpipe(dir, dentry, umode, &rpc_pipe_fops,
813 private, ops, flags);
814 if (err)
815 goto out_err;
816out:
817 mutex_unlock(&dir->i_mutex);
818 return dentry;
819out_err:
820 dentry = ERR_PTR(err);
821 printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
822 __FILE__, __func__, parent->d_name.name, name,
823 err);
824 goto out;
825}
826EXPORT_SYMBOL_GPL(rpc_mkpipe);
827
828/**
829 * rpc_unlink - remove a pipe
830 * @dentry: dentry for the pipe, as returned from rpc_mkpipe
831 *
832 * After this call, lookups will no longer find the pipe, and any
833 * attempts to read or write using preexisting opens of the pipe will
834 * return -EPIPE.
835 */
836int
837rpc_unlink(struct dentry *dentry)
838{
839 struct dentry *parent;
840 struct inode *dir;
841 int error = 0;
842
843 parent = dget_parent(dentry);
844 dir = parent->d_inode;
845 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
846 error = __rpc_rmpipe(dir, dentry);
847 mutex_unlock(&dir->i_mutex);
848 dput(parent);
849 return error;
850}
851EXPORT_SYMBOL_GPL(rpc_unlink);
852
853enum {
854 RPCAUTH_info,
855 RPCAUTH_EOF
856};
857
858static const struct rpc_filelist authfiles[] = {
859 [RPCAUTH_info] = {
860 .name = "info",
861 .i_fop = &rpc_info_operations,
862 .mode = S_IFREG | S_IRUSR,
863 },
864};
865
866static int rpc_clntdir_populate(struct dentry *dentry, void *private)
867{
868 return rpc_populate(dentry,
869 authfiles, RPCAUTH_info, RPCAUTH_EOF,
870 private);
871}
872
873static void rpc_clntdir_depopulate(struct dentry *dentry)
874{
875 rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
876}
877
878/**
879 * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
880 * @dentry: dentry from the rpc_pipefs root to the new directory
881 * @name: &struct qstr for the name
882 * @rpc_client: rpc client to associate with this directory
883 *
884 * This creates a directory at the given @path associated with
885 * @rpc_clnt, which will contain a file named "info" with some basic
886 * information about the client, together with any "pipes" that may
887 * later be created using rpc_mkpipe().
888 */
889struct dentry *rpc_create_client_dir(struct dentry *dentry,
890 struct qstr *name,
891 struct rpc_clnt *rpc_client)
892{
893 return rpc_mkdir_populate(dentry, name, S_IRUGO | S_IXUGO, NULL,
894 rpc_clntdir_populate, rpc_client);
895}
896
897/**
898 * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
899 * @dentry: directory to remove
900 */
901int rpc_remove_client_dir(struct dentry *dentry)
902{
903 return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
904}
905
906static const struct rpc_filelist cache_pipefs_files[3] = {
907 [0] = {
908 .name = "channel",
909 .i_fop = &cache_file_operations_pipefs,
910 .mode = S_IFREG|S_IRUSR|S_IWUSR,
911 },
912 [1] = {
913 .name = "content",
914 .i_fop = &content_file_operations_pipefs,
915 .mode = S_IFREG|S_IRUSR,
916 },
917 [2] = {
918 .name = "flush",
919 .i_fop = &cache_flush_operations_pipefs,
920 .mode = S_IFREG|S_IRUSR|S_IWUSR,
921 },
922};
923
924static int rpc_cachedir_populate(struct dentry *dentry, void *private)
925{
926 return rpc_populate(dentry,
927 cache_pipefs_files, 0, 3,
928 private);
929}
930
931static void rpc_cachedir_depopulate(struct dentry *dentry)
932{
933 rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
934}
935
936struct dentry *rpc_create_cache_dir(struct dentry *parent, struct qstr *name,
937 mode_t umode, struct cache_detail *cd)
938{
939 return rpc_mkdir_populate(parent, name, umode, NULL,
940 rpc_cachedir_populate, cd);
941}
942
943void rpc_remove_cache_dir(struct dentry *dentry)
944{
945 rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
946}
947
948/*
949 * populate the filesystem
950 */
951static const struct super_operations s_ops = {
952 .alloc_inode = rpc_alloc_inode,
953 .destroy_inode = rpc_destroy_inode,
954 .statfs = simple_statfs,
955};
956
957#define RPCAUTH_GSSMAGIC 0x67596969
958
959/*
960 * We have a single directory with 1 node in it.
961 */
962enum {
963 RPCAUTH_lockd,
964 RPCAUTH_mount,
965 RPCAUTH_nfs,
966 RPCAUTH_portmap,
967 RPCAUTH_statd,
968 RPCAUTH_nfsd4_cb,
969 RPCAUTH_cache,
970 RPCAUTH_RootEOF
971};
972
973static const struct rpc_filelist files[] = {
974 [RPCAUTH_lockd] = {
975 .name = "lockd",
976 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
977 },
978 [RPCAUTH_mount] = {
979 .name = "mount",
980 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
981 },
982 [RPCAUTH_nfs] = {
983 .name = "nfs",
984 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
985 },
986 [RPCAUTH_portmap] = {
987 .name = "portmap",
988 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
989 },
990 [RPCAUTH_statd] = {
991 .name = "statd",
992 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
993 },
994 [RPCAUTH_nfsd4_cb] = {
995 .name = "nfsd4_cb",
996 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
997 },
998 [RPCAUTH_cache] = {
999 .name = "cache",
1000 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1001 },
1002};
1003
1004static int
1005rpc_fill_super(struct super_block *sb, void *data, int silent)
1006{
1007 struct inode *inode;
1008 struct dentry *root;
1009
1010 sb->s_blocksize = PAGE_CACHE_SIZE;
1011 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1012 sb->s_magic = RPCAUTH_GSSMAGIC;
1013 sb->s_op = &s_ops;
1014 sb->s_time_gran = 1;
1015
1016 inode = rpc_get_inode(sb, S_IFDIR | 0755);
1017 if (!inode)
1018 return -ENOMEM;
1019 sb->s_root = root = d_alloc_root(inode);
1020 if (!root) {
1021 iput(inode);
1022 return -ENOMEM;
1023 }
1024 if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
1025 return -ENOMEM;
1026 return 0;
1027}
1028
1029static struct dentry *
1030rpc_mount(struct file_system_type *fs_type,
1031 int flags, const char *dev_name, void *data)
1032{
1033 return mount_single(fs_type, flags, data, rpc_fill_super);
1034}
1035
1036static struct file_system_type rpc_pipe_fs_type = {
1037 .owner = THIS_MODULE,
1038 .name = "rpc_pipefs",
1039 .mount = rpc_mount,
1040 .kill_sb = kill_litter_super,
1041};
1042
1043static void
1044init_once(void *foo)
1045{
1046 struct rpc_inode *rpci = (struct rpc_inode *) foo;
1047
1048 inode_init_once(&rpci->vfs_inode);
1049 rpci->private = NULL;
1050 rpci->nreaders = 0;
1051 rpci->nwriters = 0;
1052 INIT_LIST_HEAD(&rpci->in_upcall);
1053 INIT_LIST_HEAD(&rpci->in_downcall);
1054 INIT_LIST_HEAD(&rpci->pipe);
1055 rpci->pipelen = 0;
1056 init_waitqueue_head(&rpci->waitq);
1057 INIT_DELAYED_WORK(&rpci->queue_timeout,
1058 rpc_timeout_upcall_queue);
1059 rpci->ops = NULL;
1060}
1061
1062int register_rpc_pipefs(void)
1063{
1064 int err;
1065
1066 rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1067 sizeof(struct rpc_inode),
1068 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1069 SLAB_MEM_SPREAD),
1070 init_once);
1071 if (!rpc_inode_cachep)
1072 return -ENOMEM;
1073 err = register_filesystem(&rpc_pipe_fs_type);
1074 if (err) {
1075 kmem_cache_destroy(rpc_inode_cachep);
1076 return err;
1077 }
1078
1079 return 0;
1080}
1081
1082void unregister_rpc_pipefs(void)
1083{
1084 kmem_cache_destroy(rpc_inode_cachep);
1085 unregister_filesystem(&rpc_pipe_fs_type);
1086}