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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 | #include <linux/smp_lock.h> |
31 | |
32 | static struct vfsmount *rpc_mount __read_mostly; |
33 | static int rpc_mount_count; |
34 | |
35 | static struct file_system_type rpc_pipe_fs_type; |
36 | |
37 | |
38 | static struct kmem_cache *rpc_inode_cachep __read_mostly; |
39 | |
40 | #define RPC_UPCALL_TIMEOUT (30*HZ) |
41 | |
42 | static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head, |
43 | void (*destroy_msg)(struct rpc_pipe_msg *), int err) |
44 | { |
45 | struct rpc_pipe_msg *msg; |
46 | |
47 | if (list_empty(head)) |
48 | return; |
49 | do { |
50 | msg = list_entry(head->next, struct rpc_pipe_msg, list); |
51 | list_del_init(&msg->list); |
52 | msg->errno = err; |
53 | destroy_msg(msg); |
54 | } while (!list_empty(head)); |
55 | wake_up(&rpci->waitq); |
56 | } |
57 | |
58 | static void |
59 | rpc_timeout_upcall_queue(struct work_struct *work) |
60 | { |
61 | LIST_HEAD(free_list); |
62 | struct rpc_inode *rpci = |
63 | container_of(work, struct rpc_inode, queue_timeout.work); |
64 | struct inode *inode = &rpci->vfs_inode; |
65 | void (*destroy_msg)(struct rpc_pipe_msg *); |
66 | |
67 | spin_lock(&inode->i_lock); |
68 | if (rpci->ops == NULL) { |
69 | spin_unlock(&inode->i_lock); |
70 | return; |
71 | } |
72 | destroy_msg = rpci->ops->destroy_msg; |
73 | if (rpci->nreaders == 0) { |
74 | list_splice_init(&rpci->pipe, &free_list); |
75 | rpci->pipelen = 0; |
76 | } |
77 | spin_unlock(&inode->i_lock); |
78 | rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT); |
79 | } |
80 | |
81 | /** |
82 | * rpc_queue_upcall - queue an upcall message to userspace |
83 | * @inode: inode of upcall pipe on which to queue given message |
84 | * @msg: message to queue |
85 | * |
86 | * Call with an @inode created by rpc_mkpipe() to queue an upcall. |
87 | * A userspace process may then later read the upcall by performing a |
88 | * read on an open file for this inode. It is up to the caller to |
89 | * initialize the fields of @msg (other than @msg->list) appropriately. |
90 | */ |
91 | int |
92 | rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg) |
93 | { |
94 | struct rpc_inode *rpci = RPC_I(inode); |
95 | int res = -EPIPE; |
96 | |
97 | spin_lock(&inode->i_lock); |
98 | if (rpci->ops == NULL) |
99 | goto out; |
100 | if (rpci->nreaders) { |
101 | list_add_tail(&msg->list, &rpci->pipe); |
102 | rpci->pipelen += msg->len; |
103 | res = 0; |
104 | } else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) { |
105 | if (list_empty(&rpci->pipe)) |
106 | queue_delayed_work(rpciod_workqueue, |
107 | &rpci->queue_timeout, |
108 | RPC_UPCALL_TIMEOUT); |
109 | list_add_tail(&msg->list, &rpci->pipe); |
110 | rpci->pipelen += msg->len; |
111 | res = 0; |
112 | } |
113 | out: |
114 | spin_unlock(&inode->i_lock); |
115 | wake_up(&rpci->waitq); |
116 | return res; |
117 | } |
118 | EXPORT_SYMBOL_GPL(rpc_queue_upcall); |
119 | |
120 | static inline void |
121 | rpc_inode_setowner(struct inode *inode, void *private) |
122 | { |
123 | RPC_I(inode)->private = private; |
124 | } |
125 | |
126 | static void |
127 | rpc_close_pipes(struct inode *inode) |
128 | { |
129 | struct rpc_inode *rpci = RPC_I(inode); |
130 | const struct rpc_pipe_ops *ops; |
131 | int need_release; |
132 | |
133 | mutex_lock(&inode->i_mutex); |
134 | ops = rpci->ops; |
135 | if (ops != NULL) { |
136 | LIST_HEAD(free_list); |
137 | spin_lock(&inode->i_lock); |
138 | need_release = rpci->nreaders != 0 || rpci->nwriters != 0; |
139 | rpci->nreaders = 0; |
140 | list_splice_init(&rpci->in_upcall, &free_list); |
141 | list_splice_init(&rpci->pipe, &free_list); |
142 | rpci->pipelen = 0; |
143 | rpci->ops = NULL; |
144 | spin_unlock(&inode->i_lock); |
145 | rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE); |
146 | rpci->nwriters = 0; |
147 | if (need_release && ops->release_pipe) |
148 | ops->release_pipe(inode); |
149 | cancel_delayed_work_sync(&rpci->queue_timeout); |
150 | } |
151 | rpc_inode_setowner(inode, NULL); |
152 | mutex_unlock(&inode->i_mutex); |
153 | } |
154 | |
155 | static struct inode * |
156 | rpc_alloc_inode(struct super_block *sb) |
157 | { |
158 | struct rpc_inode *rpci; |
159 | rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL); |
160 | if (!rpci) |
161 | return NULL; |
162 | return &rpci->vfs_inode; |
163 | } |
164 | |
165 | static void |
166 | rpc_destroy_inode(struct inode *inode) |
167 | { |
168 | kmem_cache_free(rpc_inode_cachep, RPC_I(inode)); |
169 | } |
170 | |
171 | static int |
172 | rpc_pipe_open(struct inode *inode, struct file *filp) |
173 | { |
174 | struct rpc_inode *rpci = RPC_I(inode); |
175 | int first_open; |
176 | int res = -ENXIO; |
177 | |
178 | mutex_lock(&inode->i_mutex); |
179 | if (rpci->ops == NULL) |
180 | goto out; |
181 | first_open = rpci->nreaders == 0 && rpci->nwriters == 0; |
182 | if (first_open && rpci->ops->open_pipe) { |
183 | res = rpci->ops->open_pipe(inode); |
184 | if (res) |
185 | goto out; |
186 | } |
187 | if (filp->f_mode & FMODE_READ) |
188 | rpci->nreaders++; |
189 | if (filp->f_mode & FMODE_WRITE) |
190 | rpci->nwriters++; |
191 | res = 0; |
192 | out: |
193 | mutex_unlock(&inode->i_mutex); |
194 | return res; |
195 | } |
196 | |
197 | static int |
198 | rpc_pipe_release(struct inode *inode, struct file *filp) |
199 | { |
200 | struct rpc_inode *rpci = RPC_I(inode); |
201 | struct rpc_pipe_msg *msg; |
202 | int last_close; |
203 | |
204 | mutex_lock(&inode->i_mutex); |
205 | if (rpci->ops == NULL) |
206 | goto out; |
207 | msg = (struct rpc_pipe_msg *)filp->private_data; |
208 | if (msg != NULL) { |
209 | spin_lock(&inode->i_lock); |
210 | msg->errno = -EAGAIN; |
211 | list_del_init(&msg->list); |
212 | spin_unlock(&inode->i_lock); |
213 | rpci->ops->destroy_msg(msg); |
214 | } |
215 | if (filp->f_mode & FMODE_WRITE) |
216 | rpci->nwriters --; |
217 | if (filp->f_mode & FMODE_READ) { |
218 | rpci->nreaders --; |
219 | if (rpci->nreaders == 0) { |
220 | LIST_HEAD(free_list); |
221 | spin_lock(&inode->i_lock); |
222 | list_splice_init(&rpci->pipe, &free_list); |
223 | rpci->pipelen = 0; |
224 | spin_unlock(&inode->i_lock); |
225 | rpc_purge_list(rpci, &free_list, |
226 | rpci->ops->destroy_msg, -EAGAIN); |
227 | } |
228 | } |
229 | last_close = rpci->nwriters == 0 && rpci->nreaders == 0; |
230 | if (last_close && rpci->ops->release_pipe) |
231 | rpci->ops->release_pipe(inode); |
232 | out: |
233 | mutex_unlock(&inode->i_mutex); |
234 | return 0; |
235 | } |
236 | |
237 | static ssize_t |
238 | rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset) |
239 | { |
240 | struct inode *inode = filp->f_path.dentry->d_inode; |
241 | struct rpc_inode *rpci = RPC_I(inode); |
242 | struct rpc_pipe_msg *msg; |
243 | int res = 0; |
244 | |
245 | mutex_lock(&inode->i_mutex); |
246 | if (rpci->ops == NULL) { |
247 | res = -EPIPE; |
248 | goto out_unlock; |
249 | } |
250 | msg = filp->private_data; |
251 | if (msg == NULL) { |
252 | spin_lock(&inode->i_lock); |
253 | if (!list_empty(&rpci->pipe)) { |
254 | msg = list_entry(rpci->pipe.next, |
255 | struct rpc_pipe_msg, |
256 | list); |
257 | list_move(&msg->list, &rpci->in_upcall); |
258 | rpci->pipelen -= msg->len; |
259 | filp->private_data = msg; |
260 | msg->copied = 0; |
261 | } |
262 | spin_unlock(&inode->i_lock); |
263 | if (msg == NULL) |
264 | goto out_unlock; |
265 | } |
266 | /* NOTE: it is up to the callback to update msg->copied */ |
267 | res = rpci->ops->upcall(filp, msg, buf, len); |
268 | if (res < 0 || msg->len == msg->copied) { |
269 | filp->private_data = NULL; |
270 | spin_lock(&inode->i_lock); |
271 | list_del_init(&msg->list); |
272 | spin_unlock(&inode->i_lock); |
273 | rpci->ops->destroy_msg(msg); |
274 | } |
275 | out_unlock: |
276 | mutex_unlock(&inode->i_mutex); |
277 | return res; |
278 | } |
279 | |
280 | static ssize_t |
281 | rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset) |
282 | { |
283 | struct inode *inode = filp->f_path.dentry->d_inode; |
284 | struct rpc_inode *rpci = RPC_I(inode); |
285 | int res; |
286 | |
287 | mutex_lock(&inode->i_mutex); |
288 | res = -EPIPE; |
289 | if (rpci->ops != NULL) |
290 | res = rpci->ops->downcall(filp, buf, len); |
291 | mutex_unlock(&inode->i_mutex); |
292 | return res; |
293 | } |
294 | |
295 | static unsigned int |
296 | rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait) |
297 | { |
298 | struct rpc_inode *rpci; |
299 | unsigned int mask = 0; |
300 | |
301 | rpci = RPC_I(filp->f_path.dentry->d_inode); |
302 | poll_wait(filp, &rpci->waitq, wait); |
303 | |
304 | mask = POLLOUT | POLLWRNORM; |
305 | if (rpci->ops == NULL) |
306 | mask |= POLLERR | POLLHUP; |
307 | if (filp->private_data || !list_empty(&rpci->pipe)) |
308 | mask |= POLLIN | POLLRDNORM; |
309 | return mask; |
310 | } |
311 | |
312 | static int |
313 | rpc_pipe_ioctl_unlocked(struct file *filp, unsigned int cmd, unsigned long arg) |
314 | { |
315 | struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode); |
316 | int len; |
317 | |
318 | switch (cmd) { |
319 | case FIONREAD: |
320 | if (rpci->ops == NULL) |
321 | return -EPIPE; |
322 | len = rpci->pipelen; |
323 | if (filp->private_data) { |
324 | struct rpc_pipe_msg *msg; |
325 | msg = (struct rpc_pipe_msg *)filp->private_data; |
326 | len += msg->len - msg->copied; |
327 | } |
328 | return put_user(len, (int __user *)arg); |
329 | default: |
330 | return -EINVAL; |
331 | } |
332 | } |
333 | |
334 | static long |
335 | rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
336 | { |
337 | long ret; |
338 | |
339 | lock_kernel(); |
340 | ret = rpc_pipe_ioctl_unlocked(filp, cmd, arg); |
341 | unlock_kernel(); |
342 | |
343 | return ret; |
344 | } |
345 | |
346 | static 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 | |
357 | static int |
358 | rpc_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 | |
371 | static int |
372 | rpc_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 | |
395 | static int |
396 | rpc_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 | |
406 | static 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 | */ |
418 | struct rpc_filelist { |
419 | const char *name; |
420 | const struct file_operations *i_fop; |
421 | umode_t mode; |
422 | }; |
423 | |
424 | struct vfsmount *rpc_get_mount(void) |
425 | { |
426 | int err; |
427 | |
428 | err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count); |
429 | if (err != 0) |
430 | return ERR_PTR(err); |
431 | return rpc_mount; |
432 | } |
433 | EXPORT_SYMBOL_GPL(rpc_get_mount); |
434 | |
435 | void rpc_put_mount(void) |
436 | { |
437 | simple_release_fs(&rpc_mount, &rpc_mount_count); |
438 | } |
439 | EXPORT_SYMBOL_GPL(rpc_put_mount); |
440 | |
441 | static int rpc_delete_dentry(struct dentry *dentry) |
442 | { |
443 | return 1; |
444 | } |
445 | |
446 | static const struct dentry_operations rpc_dentry_operations = { |
447 | .d_delete = rpc_delete_dentry, |
448 | }; |
449 | |
450 | static struct inode * |
451 | rpc_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_mode = mode; |
457 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
458 | switch(mode & S_IFMT) { |
459 | case S_IFDIR: |
460 | inode->i_fop = &simple_dir_operations; |
461 | inode->i_op = &simple_dir_inode_operations; |
462 | inc_nlink(inode); |
463 | default: |
464 | break; |
465 | } |
466 | return inode; |
467 | } |
468 | |
469 | static int __rpc_create_common(struct inode *dir, struct dentry *dentry, |
470 | umode_t mode, |
471 | const struct file_operations *i_fop, |
472 | void *private) |
473 | { |
474 | struct inode *inode; |
475 | |
476 | BUG_ON(!d_unhashed(dentry)); |
477 | inode = rpc_get_inode(dir->i_sb, mode); |
478 | if (!inode) |
479 | goto out_err; |
480 | inode->i_ino = iunique(dir->i_sb, 100); |
481 | if (i_fop) |
482 | inode->i_fop = i_fop; |
483 | if (private) |
484 | rpc_inode_setowner(inode, private); |
485 | d_add(dentry, inode); |
486 | return 0; |
487 | out_err: |
488 | printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n", |
489 | __FILE__, __func__, dentry->d_name.name); |
490 | dput(dentry); |
491 | return -ENOMEM; |
492 | } |
493 | |
494 | static int __rpc_create(struct inode *dir, struct dentry *dentry, |
495 | umode_t mode, |
496 | const struct file_operations *i_fop, |
497 | void *private) |
498 | { |
499 | int err; |
500 | |
501 | err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private); |
502 | if (err) |
503 | return err; |
504 | fsnotify_create(dir, dentry); |
505 | return 0; |
506 | } |
507 | |
508 | static int __rpc_mkdir(struct inode *dir, struct dentry *dentry, |
509 | umode_t mode, |
510 | const struct file_operations *i_fop, |
511 | void *private) |
512 | { |
513 | int err; |
514 | |
515 | err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private); |
516 | if (err) |
517 | return err; |
518 | inc_nlink(dir); |
519 | fsnotify_mkdir(dir, dentry); |
520 | return 0; |
521 | } |
522 | |
523 | static int __rpc_mkpipe(struct inode *dir, struct dentry *dentry, |
524 | umode_t mode, |
525 | const struct file_operations *i_fop, |
526 | void *private, |
527 | const struct rpc_pipe_ops *ops, |
528 | int flags) |
529 | { |
530 | struct rpc_inode *rpci; |
531 | int err; |
532 | |
533 | err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private); |
534 | if (err) |
535 | return err; |
536 | rpci = RPC_I(dentry->d_inode); |
537 | rpci->nkern_readwriters = 1; |
538 | rpci->private = private; |
539 | rpci->flags = flags; |
540 | rpci->ops = ops; |
541 | fsnotify_create(dir, dentry); |
542 | return 0; |
543 | } |
544 | |
545 | static int __rpc_rmdir(struct inode *dir, struct dentry *dentry) |
546 | { |
547 | int ret; |
548 | |
549 | dget(dentry); |
550 | ret = simple_rmdir(dir, dentry); |
551 | d_delete(dentry); |
552 | dput(dentry); |
553 | return ret; |
554 | } |
555 | |
556 | static int __rpc_unlink(struct inode *dir, struct dentry *dentry) |
557 | { |
558 | int ret; |
559 | |
560 | dget(dentry); |
561 | ret = simple_unlink(dir, dentry); |
562 | d_delete(dentry); |
563 | dput(dentry); |
564 | return ret; |
565 | } |
566 | |
567 | static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry) |
568 | { |
569 | struct inode *inode = dentry->d_inode; |
570 | struct rpc_inode *rpci = RPC_I(inode); |
571 | |
572 | rpci->nkern_readwriters--; |
573 | if (rpci->nkern_readwriters != 0) |
574 | return 0; |
575 | rpc_close_pipes(inode); |
576 | return __rpc_unlink(dir, dentry); |
577 | } |
578 | |
579 | static struct dentry *__rpc_lookup_create(struct dentry *parent, |
580 | struct qstr *name) |
581 | { |
582 | struct dentry *dentry; |
583 | |
584 | dentry = d_lookup(parent, name); |
585 | if (!dentry) { |
586 | dentry = d_alloc(parent, name); |
587 | if (!dentry) { |
588 | dentry = ERR_PTR(-ENOMEM); |
589 | goto out_err; |
590 | } |
591 | } |
592 | if (!dentry->d_inode) |
593 | dentry->d_op = &rpc_dentry_operations; |
594 | out_err: |
595 | return dentry; |
596 | } |
597 | |
598 | static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent, |
599 | struct qstr *name) |
600 | { |
601 | struct dentry *dentry; |
602 | |
603 | dentry = __rpc_lookup_create(parent, name); |
604 | if (IS_ERR(dentry)) |
605 | return dentry; |
606 | if (dentry->d_inode == NULL) |
607 | return dentry; |
608 | dput(dentry); |
609 | return ERR_PTR(-EEXIST); |
610 | } |
611 | |
612 | /* |
613 | * FIXME: This probably has races. |
614 | */ |
615 | static void __rpc_depopulate(struct dentry *parent, |
616 | const struct rpc_filelist *files, |
617 | int start, int eof) |
618 | { |
619 | struct inode *dir = parent->d_inode; |
620 | struct dentry *dentry; |
621 | struct qstr name; |
622 | int i; |
623 | |
624 | for (i = start; i < eof; i++) { |
625 | name.name = files[i].name; |
626 | name.len = strlen(files[i].name); |
627 | name.hash = full_name_hash(name.name, name.len); |
628 | dentry = d_lookup(parent, &name); |
629 | |
630 | if (dentry == NULL) |
631 | continue; |
632 | if (dentry->d_inode == NULL) |
633 | goto next; |
634 | switch (dentry->d_inode->i_mode & S_IFMT) { |
635 | default: |
636 | BUG(); |
637 | case S_IFREG: |
638 | __rpc_unlink(dir, dentry); |
639 | break; |
640 | case S_IFDIR: |
641 | __rpc_rmdir(dir, dentry); |
642 | } |
643 | next: |
644 | dput(dentry); |
645 | } |
646 | } |
647 | |
648 | static void rpc_depopulate(struct dentry *parent, |
649 | const struct rpc_filelist *files, |
650 | int start, int eof) |
651 | { |
652 | struct inode *dir = parent->d_inode; |
653 | |
654 | mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD); |
655 | __rpc_depopulate(parent, files, start, eof); |
656 | mutex_unlock(&dir->i_mutex); |
657 | } |
658 | |
659 | static int rpc_populate(struct dentry *parent, |
660 | const struct rpc_filelist *files, |
661 | int start, int eof, |
662 | void *private) |
663 | { |
664 | struct inode *dir = parent->d_inode; |
665 | struct dentry *dentry; |
666 | int i, err; |
667 | |
668 | mutex_lock(&dir->i_mutex); |
669 | for (i = start; i < eof; i++) { |
670 | struct qstr q; |
671 | |
672 | q.name = files[i].name; |
673 | q.len = strlen(files[i].name); |
674 | q.hash = full_name_hash(q.name, q.len); |
675 | dentry = __rpc_lookup_create_exclusive(parent, &q); |
676 | err = PTR_ERR(dentry); |
677 | if (IS_ERR(dentry)) |
678 | goto out_bad; |
679 | switch (files[i].mode & S_IFMT) { |
680 | default: |
681 | BUG(); |
682 | case S_IFREG: |
683 | err = __rpc_create(dir, dentry, |
684 | files[i].mode, |
685 | files[i].i_fop, |
686 | private); |
687 | break; |
688 | case S_IFDIR: |
689 | err = __rpc_mkdir(dir, dentry, |
690 | files[i].mode, |
691 | NULL, |
692 | private); |
693 | } |
694 | if (err != 0) |
695 | goto out_bad; |
696 | } |
697 | mutex_unlock(&dir->i_mutex); |
698 | return 0; |
699 | out_bad: |
700 | __rpc_depopulate(parent, files, start, eof); |
701 | mutex_unlock(&dir->i_mutex); |
702 | printk(KERN_WARNING "%s: %s failed to populate directory %s\n", |
703 | __FILE__, __func__, parent->d_name.name); |
704 | return err; |
705 | } |
706 | |
707 | static struct dentry *rpc_mkdir_populate(struct dentry *parent, |
708 | struct qstr *name, umode_t mode, void *private, |
709 | int (*populate)(struct dentry *, void *), void *args_populate) |
710 | { |
711 | struct dentry *dentry; |
712 | struct inode *dir = parent->d_inode; |
713 | int error; |
714 | |
715 | mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); |
716 | dentry = __rpc_lookup_create_exclusive(parent, name); |
717 | if (IS_ERR(dentry)) |
718 | goto out; |
719 | error = __rpc_mkdir(dir, dentry, mode, NULL, private); |
720 | if (error != 0) |
721 | goto out_err; |
722 | if (populate != NULL) { |
723 | error = populate(dentry, args_populate); |
724 | if (error) |
725 | goto err_rmdir; |
726 | } |
727 | out: |
728 | mutex_unlock(&dir->i_mutex); |
729 | return dentry; |
730 | err_rmdir: |
731 | __rpc_rmdir(dir, dentry); |
732 | out_err: |
733 | dentry = ERR_PTR(error); |
734 | goto out; |
735 | } |
736 | |
737 | static int rpc_rmdir_depopulate(struct dentry *dentry, |
738 | void (*depopulate)(struct dentry *)) |
739 | { |
740 | struct dentry *parent; |
741 | struct inode *dir; |
742 | int error; |
743 | |
744 | parent = dget_parent(dentry); |
745 | dir = parent->d_inode; |
746 | mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); |
747 | if (depopulate != NULL) |
748 | depopulate(dentry); |
749 | error = __rpc_rmdir(dir, dentry); |
750 | mutex_unlock(&dir->i_mutex); |
751 | dput(parent); |
752 | return error; |
753 | } |
754 | |
755 | /** |
756 | * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication |
757 | * @parent: dentry of directory to create new "pipe" in |
758 | * @name: name of pipe |
759 | * @private: private data to associate with the pipe, for the caller's use |
760 | * @ops: operations defining the behavior of the pipe: upcall, downcall, |
761 | * release_pipe, open_pipe, and destroy_msg. |
762 | * @flags: rpc_inode flags |
763 | * |
764 | * Data is made available for userspace to read by calls to |
765 | * rpc_queue_upcall(). The actual reads will result in calls to |
766 | * @ops->upcall, which will be called with the file pointer, |
767 | * message, and userspace buffer to copy to. |
768 | * |
769 | * Writes can come at any time, and do not necessarily have to be |
770 | * responses to upcalls. They will result in calls to @msg->downcall. |
771 | * |
772 | * The @private argument passed here will be available to all these methods |
773 | * from the file pointer, via RPC_I(file->f_dentry->d_inode)->private. |
774 | */ |
775 | struct dentry *rpc_mkpipe(struct dentry *parent, const char *name, |
776 | void *private, const struct rpc_pipe_ops *ops, |
777 | int flags) |
778 | { |
779 | struct dentry *dentry; |
780 | struct inode *dir = parent->d_inode; |
781 | umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR; |
782 | struct qstr q; |
783 | int err; |
784 | |
785 | if (ops->upcall == NULL) |
786 | umode &= ~S_IRUGO; |
787 | if (ops->downcall == NULL) |
788 | umode &= ~S_IWUGO; |
789 | |
790 | q.name = name; |
791 | q.len = strlen(name); |
792 | q.hash = full_name_hash(q.name, q.len), |
793 | |
794 | mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); |
795 | dentry = __rpc_lookup_create(parent, &q); |
796 | if (IS_ERR(dentry)) |
797 | goto out; |
798 | if (dentry->d_inode) { |
799 | struct rpc_inode *rpci = RPC_I(dentry->d_inode); |
800 | if (rpci->private != private || |
801 | rpci->ops != ops || |
802 | rpci->flags != flags) { |
803 | dput (dentry); |
804 | err = -EBUSY; |
805 | goto out_err; |
806 | } |
807 | rpci->nkern_readwriters++; |
808 | goto out; |
809 | } |
810 | |
811 | err = __rpc_mkpipe(dir, dentry, umode, &rpc_pipe_fops, |
812 | private, ops, flags); |
813 | if (err) |
814 | goto out_err; |
815 | out: |
816 | mutex_unlock(&dir->i_mutex); |
817 | return dentry; |
818 | out_err: |
819 | dentry = ERR_PTR(err); |
820 | printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n", |
821 | __FILE__, __func__, parent->d_name.name, name, |
822 | err); |
823 | goto out; |
824 | } |
825 | EXPORT_SYMBOL_GPL(rpc_mkpipe); |
826 | |
827 | /** |
828 | * rpc_unlink - remove a pipe |
829 | * @dentry: dentry for the pipe, as returned from rpc_mkpipe |
830 | * |
831 | * After this call, lookups will no longer find the pipe, and any |
832 | * attempts to read or write using preexisting opens of the pipe will |
833 | * return -EPIPE. |
834 | */ |
835 | int |
836 | rpc_unlink(struct dentry *dentry) |
837 | { |
838 | struct dentry *parent; |
839 | struct inode *dir; |
840 | int error = 0; |
841 | |
842 | parent = dget_parent(dentry); |
843 | dir = parent->d_inode; |
844 | mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); |
845 | error = __rpc_rmpipe(dir, dentry); |
846 | mutex_unlock(&dir->i_mutex); |
847 | dput(parent); |
848 | return error; |
849 | } |
850 | EXPORT_SYMBOL_GPL(rpc_unlink); |
851 | |
852 | enum { |
853 | RPCAUTH_info, |
854 | RPCAUTH_EOF |
855 | }; |
856 | |
857 | static const struct rpc_filelist authfiles[] = { |
858 | [RPCAUTH_info] = { |
859 | .name = "info", |
860 | .i_fop = &rpc_info_operations, |
861 | .mode = S_IFREG | S_IRUSR, |
862 | }, |
863 | }; |
864 | |
865 | static int rpc_clntdir_populate(struct dentry *dentry, void *private) |
866 | { |
867 | return rpc_populate(dentry, |
868 | authfiles, RPCAUTH_info, RPCAUTH_EOF, |
869 | private); |
870 | } |
871 | |
872 | static void rpc_clntdir_depopulate(struct dentry *dentry) |
873 | { |
874 | rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF); |
875 | } |
876 | |
877 | /** |
878 | * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs |
879 | * @dentry: dentry from the rpc_pipefs root to the new directory |
880 | * @name: &struct qstr for the name |
881 | * @rpc_client: rpc client to associate with this directory |
882 | * |
883 | * This creates a directory at the given @path associated with |
884 | * @rpc_clnt, which will contain a file named "info" with some basic |
885 | * information about the client, together with any "pipes" that may |
886 | * later be created using rpc_mkpipe(). |
887 | */ |
888 | struct dentry *rpc_create_client_dir(struct dentry *dentry, |
889 | struct qstr *name, |
890 | struct rpc_clnt *rpc_client) |
891 | { |
892 | return rpc_mkdir_populate(dentry, name, S_IRUGO | S_IXUGO, NULL, |
893 | rpc_clntdir_populate, rpc_client); |
894 | } |
895 | |
896 | /** |
897 | * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir() |
898 | * @dentry: directory to remove |
899 | */ |
900 | int rpc_remove_client_dir(struct dentry *dentry) |
901 | { |
902 | return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate); |
903 | } |
904 | |
905 | static const struct rpc_filelist cache_pipefs_files[3] = { |
906 | [0] = { |
907 | .name = "channel", |
908 | .i_fop = &cache_file_operations_pipefs, |
909 | .mode = S_IFREG|S_IRUSR|S_IWUSR, |
910 | }, |
911 | [1] = { |
912 | .name = "content", |
913 | .i_fop = &content_file_operations_pipefs, |
914 | .mode = S_IFREG|S_IRUSR, |
915 | }, |
916 | [2] = { |
917 | .name = "flush", |
918 | .i_fop = &cache_flush_operations_pipefs, |
919 | .mode = S_IFREG|S_IRUSR|S_IWUSR, |
920 | }, |
921 | }; |
922 | |
923 | static int rpc_cachedir_populate(struct dentry *dentry, void *private) |
924 | { |
925 | return rpc_populate(dentry, |
926 | cache_pipefs_files, 0, 3, |
927 | private); |
928 | } |
929 | |
930 | static void rpc_cachedir_depopulate(struct dentry *dentry) |
931 | { |
932 | rpc_depopulate(dentry, cache_pipefs_files, 0, 3); |
933 | } |
934 | |
935 | struct dentry *rpc_create_cache_dir(struct dentry *parent, struct qstr *name, |
936 | mode_t umode, struct cache_detail *cd) |
937 | { |
938 | return rpc_mkdir_populate(parent, name, umode, NULL, |
939 | rpc_cachedir_populate, cd); |
940 | } |
941 | |
942 | void rpc_remove_cache_dir(struct dentry *dentry) |
943 | { |
944 | rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate); |
945 | } |
946 | |
947 | /* |
948 | * populate the filesystem |
949 | */ |
950 | static const struct super_operations s_ops = { |
951 | .alloc_inode = rpc_alloc_inode, |
952 | .destroy_inode = rpc_destroy_inode, |
953 | .statfs = simple_statfs, |
954 | }; |
955 | |
956 | #define RPCAUTH_GSSMAGIC 0x67596969 |
957 | |
958 | /* |
959 | * We have a single directory with 1 node in it. |
960 | */ |
961 | enum { |
962 | RPCAUTH_lockd, |
963 | RPCAUTH_mount, |
964 | RPCAUTH_nfs, |
965 | RPCAUTH_portmap, |
966 | RPCAUTH_statd, |
967 | RPCAUTH_nfsd4_cb, |
968 | RPCAUTH_cache, |
969 | RPCAUTH_RootEOF |
970 | }; |
971 | |
972 | static const struct rpc_filelist files[] = { |
973 | [RPCAUTH_lockd] = { |
974 | .name = "lockd", |
975 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, |
976 | }, |
977 | [RPCAUTH_mount] = { |
978 | .name = "mount", |
979 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, |
980 | }, |
981 | [RPCAUTH_nfs] = { |
982 | .name = "nfs", |
983 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, |
984 | }, |
985 | [RPCAUTH_portmap] = { |
986 | .name = "portmap", |
987 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, |
988 | }, |
989 | [RPCAUTH_statd] = { |
990 | .name = "statd", |
991 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, |
992 | }, |
993 | [RPCAUTH_nfsd4_cb] = { |
994 | .name = "nfsd4_cb", |
995 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, |
996 | }, |
997 | [RPCAUTH_cache] = { |
998 | .name = "cache", |
999 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, |
1000 | }, |
1001 | }; |
1002 | |
1003 | static int |
1004 | rpc_fill_super(struct super_block *sb, void *data, int silent) |
1005 | { |
1006 | struct inode *inode; |
1007 | struct dentry *root; |
1008 | |
1009 | sb->s_blocksize = PAGE_CACHE_SIZE; |
1010 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
1011 | sb->s_magic = RPCAUTH_GSSMAGIC; |
1012 | sb->s_op = &s_ops; |
1013 | sb->s_time_gran = 1; |
1014 | |
1015 | inode = rpc_get_inode(sb, S_IFDIR | 0755); |
1016 | if (!inode) |
1017 | return -ENOMEM; |
1018 | sb->s_root = root = d_alloc_root(inode); |
1019 | if (!root) { |
1020 | iput(inode); |
1021 | return -ENOMEM; |
1022 | } |
1023 | if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL)) |
1024 | return -ENOMEM; |
1025 | return 0; |
1026 | } |
1027 | |
1028 | static int |
1029 | rpc_get_sb(struct file_system_type *fs_type, |
1030 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
1031 | { |
1032 | return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt); |
1033 | } |
1034 | |
1035 | static struct file_system_type rpc_pipe_fs_type = { |
1036 | .owner = THIS_MODULE, |
1037 | .name = "rpc_pipefs", |
1038 | .get_sb = rpc_get_sb, |
1039 | .kill_sb = kill_litter_super, |
1040 | }; |
1041 | |
1042 | static void |
1043 | init_once(void *foo) |
1044 | { |
1045 | struct rpc_inode *rpci = (struct rpc_inode *) foo; |
1046 | |
1047 | inode_init_once(&rpci->vfs_inode); |
1048 | rpci->private = NULL; |
1049 | rpci->nreaders = 0; |
1050 | rpci->nwriters = 0; |
1051 | INIT_LIST_HEAD(&rpci->in_upcall); |
1052 | INIT_LIST_HEAD(&rpci->in_downcall); |
1053 | INIT_LIST_HEAD(&rpci->pipe); |
1054 | rpci->pipelen = 0; |
1055 | init_waitqueue_head(&rpci->waitq); |
1056 | INIT_DELAYED_WORK(&rpci->queue_timeout, |
1057 | rpc_timeout_upcall_queue); |
1058 | rpci->ops = NULL; |
1059 | } |
1060 | |
1061 | int register_rpc_pipefs(void) |
1062 | { |
1063 | int err; |
1064 | |
1065 | rpc_inode_cachep = kmem_cache_create("rpc_inode_cache", |
1066 | sizeof(struct rpc_inode), |
1067 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
1068 | SLAB_MEM_SPREAD), |
1069 | init_once); |
1070 | if (!rpc_inode_cachep) |
1071 | return -ENOMEM; |
1072 | err = register_filesystem(&rpc_pipe_fs_type); |
1073 | if (err) { |
1074 | kmem_cache_destroy(rpc_inode_cachep); |
1075 | return err; |
1076 | } |
1077 | |
1078 | return 0; |
1079 | } |
1080 | |
1081 | void unregister_rpc_pipefs(void) |
1082 | { |
1083 | kmem_cache_destroy(rpc_inode_cachep); |
1084 | unregister_filesystem(&rpc_pipe_fs_type); |
1085 | } |
1086 |
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