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Commit | Line | Data |
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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 | ||
31 | static struct vfsmount *rpc_mnt __read_mostly; | |
32 | static int rpc_mount_count; | |
33 | ||
34 | static struct file_system_type rpc_pipe_fs_type; | |
35 | ||
36 | ||
37 | static struct kmem_cache *rpc_inode_cachep __read_mostly; | |
38 | ||
39 | #define RPC_UPCALL_TIMEOUT (30*HZ) | |
40 | ||
41 | static 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 | ||
57 | static void | |
58 | rpc_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 | */ | |
90 | int | |
91 | rpc_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 | } | |
112 | out: | |
113 | spin_unlock(&inode->i_lock); | |
114 | wake_up(&rpci->waitq); | |
115 | return res; | |
116 | } | |
117 | EXPORT_SYMBOL_GPL(rpc_queue_upcall); | |
118 | ||
119 | static inline void | |
120 | rpc_inode_setowner(struct inode *inode, void *private) | |
121 | { | |
122 | RPC_I(inode)->private = private; | |
123 | } | |
124 | ||
125 | static void | |
126 | rpc_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 | ||
154 | static struct inode * | |
155 | rpc_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 | ||
164 | static void | |
165 | rpc_destroy_inode(struct inode *inode) | |
166 | { | |
167 | kmem_cache_free(rpc_inode_cachep, RPC_I(inode)); | |
168 | } | |
169 | ||
170 | static int | |
171 | rpc_pipe_open(struct inode *inode, struct file *filp) | |
172 | { | |
173 | struct rpc_inode *rpci = RPC_I(inode); | |
174 | int first_open; | |
175 | int res = -ENXIO; | |
176 | ||
177 | mutex_lock(&inode->i_mutex); | |
178 | if (rpci->ops == NULL) | |
179 | goto out; | |
180 | first_open = rpci->nreaders == 0 && rpci->nwriters == 0; | |
181 | if (first_open && rpci->ops->open_pipe) { | |
182 | res = rpci->ops->open_pipe(inode); | |
183 | if (res) | |
184 | goto out; | |
185 | } | |
186 | if (filp->f_mode & FMODE_READ) | |
187 | rpci->nreaders++; | |
188 | if (filp->f_mode & FMODE_WRITE) | |
189 | rpci->nwriters++; | |
190 | res = 0; | |
191 | out: | |
192 | mutex_unlock(&inode->i_mutex); | |
193 | return res; | |
194 | } | |
195 | ||
196 | static int | |
197 | rpc_pipe_release(struct inode *inode, struct file *filp) | |
198 | { | |
199 | struct rpc_inode *rpci = RPC_I(inode); | |
200 | struct rpc_pipe_msg *msg; | |
201 | int last_close; | |
202 | ||
203 | mutex_lock(&inode->i_mutex); | |
204 | if (rpci->ops == NULL) | |
205 | goto out; | |
206 | msg = filp->private_data; | |
207 | if (msg != NULL) { | |
208 | spin_lock(&inode->i_lock); | |
209 | msg->errno = -EAGAIN; | |
210 | list_del_init(&msg->list); | |
211 | spin_unlock(&inode->i_lock); | |
212 | rpci->ops->destroy_msg(msg); | |
213 | } | |
214 | if (filp->f_mode & FMODE_WRITE) | |
215 | rpci->nwriters --; | |
216 | if (filp->f_mode & FMODE_READ) { | |
217 | rpci->nreaders --; | |
218 | if (rpci->nreaders == 0) { | |
219 | LIST_HEAD(free_list); | |
220 | spin_lock(&inode->i_lock); | |
221 | list_splice_init(&rpci->pipe, &free_list); | |
222 | rpci->pipelen = 0; | |
223 | spin_unlock(&inode->i_lock); | |
224 | rpc_purge_list(rpci, &free_list, | |
225 | rpci->ops->destroy_msg, -EAGAIN); | |
226 | } | |
227 | } | |
228 | last_close = rpci->nwriters == 0 && rpci->nreaders == 0; | |
229 | if (last_close && rpci->ops->release_pipe) | |
230 | rpci->ops->release_pipe(inode); | |
231 | out: | |
232 | mutex_unlock(&inode->i_mutex); | |
233 | return 0; | |
234 | } | |
235 | ||
236 | static ssize_t | |
237 | rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset) | |
238 | { | |
239 | struct inode *inode = filp->f_path.dentry->d_inode; | |
240 | struct rpc_inode *rpci = RPC_I(inode); | |
241 | struct rpc_pipe_msg *msg; | |
242 | int res = 0; | |
243 | ||
244 | mutex_lock(&inode->i_mutex); | |
245 | if (rpci->ops == NULL) { | |
246 | res = -EPIPE; | |
247 | goto out_unlock; | |
248 | } | |
249 | msg = filp->private_data; | |
250 | if (msg == NULL) { | |
251 | spin_lock(&inode->i_lock); | |
252 | if (!list_empty(&rpci->pipe)) { | |
253 | msg = list_entry(rpci->pipe.next, | |
254 | struct rpc_pipe_msg, | |
255 | list); | |
256 | list_move(&msg->list, &rpci->in_upcall); | |
257 | rpci->pipelen -= msg->len; | |
258 | filp->private_data = msg; | |
259 | msg->copied = 0; | |
260 | } | |
261 | spin_unlock(&inode->i_lock); | |
262 | if (msg == NULL) | |
263 | goto out_unlock; | |
264 | } | |
265 | /* NOTE: it is up to the callback to update msg->copied */ | |
266 | res = rpci->ops->upcall(filp, msg, buf, len); | |
267 | if (res < 0 || msg->len == msg->copied) { | |
268 | filp->private_data = NULL; | |
269 | spin_lock(&inode->i_lock); | |
270 | list_del_init(&msg->list); | |
271 | spin_unlock(&inode->i_lock); | |
272 | rpci->ops->destroy_msg(msg); | |
273 | } | |
274 | out_unlock: | |
275 | mutex_unlock(&inode->i_mutex); | |
276 | return res; | |
277 | } | |
278 | ||
279 | static ssize_t | |
280 | rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset) | |
281 | { | |
282 | struct inode *inode = filp->f_path.dentry->d_inode; | |
283 | struct rpc_inode *rpci = RPC_I(inode); | |
284 | int res; | |
285 | ||
286 | mutex_lock(&inode->i_mutex); | |
287 | res = -EPIPE; | |
288 | if (rpci->ops != NULL) | |
289 | res = rpci->ops->downcall(filp, buf, len); | |
290 | mutex_unlock(&inode->i_mutex); | |
291 | return res; | |
292 | } | |
293 | ||
294 | static unsigned int | |
295 | rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait) | |
296 | { | |
297 | struct rpc_inode *rpci; | |
298 | unsigned int mask = 0; | |
299 | ||
300 | rpci = RPC_I(filp->f_path.dentry->d_inode); | |
301 | poll_wait(filp, &rpci->waitq, wait); | |
302 | ||
303 | mask = POLLOUT | POLLWRNORM; | |
304 | if (rpci->ops == NULL) | |
305 | mask |= POLLERR | POLLHUP; | |
306 | if (filp->private_data || !list_empty(&rpci->pipe)) | |
307 | mask |= POLLIN | POLLRDNORM; | |
308 | return mask; | |
309 | } | |
310 | ||
311 | static long | |
312 | rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) | |
313 | { | |
314 | struct inode *inode = filp->f_path.dentry->d_inode; | |
315 | struct rpc_inode *rpci = RPC_I(inode); | |
316 | int len; | |
317 | ||
318 | switch (cmd) { | |
319 | case FIONREAD: | |
320 | spin_lock(&inode->i_lock); | |
321 | if (rpci->ops == NULL) { | |
322 | spin_unlock(&inode->i_lock); | |
323 | return -EPIPE; | |
324 | } | |
325 | len = rpci->pipelen; | |
326 | if (filp->private_data) { | |
327 | struct rpc_pipe_msg *msg; | |
328 | msg = filp->private_data; | |
329 | len += msg->len - msg->copied; | |
330 | } | |
331 | spin_unlock(&inode->i_lock); | |
332 | return put_user(len, (int __user *)arg); | |
333 | default: | |
334 | return -EINVAL; | |
335 | } | |
336 | } | |
337 | ||
338 | static const struct file_operations rpc_pipe_fops = { | |
339 | .owner = THIS_MODULE, | |
340 | .llseek = no_llseek, | |
341 | .read = rpc_pipe_read, | |
342 | .write = rpc_pipe_write, | |
343 | .poll = rpc_pipe_poll, | |
344 | .unlocked_ioctl = rpc_pipe_ioctl, | |
345 | .open = rpc_pipe_open, | |
346 | .release = rpc_pipe_release, | |
347 | }; | |
348 | ||
349 | static int | |
350 | rpc_show_info(struct seq_file *m, void *v) | |
351 | { | |
352 | struct rpc_clnt *clnt = m->private; | |
353 | ||
354 | seq_printf(m, "RPC server: %s\n", clnt->cl_server); | |
355 | seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname, | |
356 | clnt->cl_prog, clnt->cl_vers); | |
357 | seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR)); | |
358 | seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO)); | |
359 | seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT)); | |
360 | return 0; | |
361 | } | |
362 | ||
363 | static int | |
364 | rpc_info_open(struct inode *inode, struct file *file) | |
365 | { | |
366 | struct rpc_clnt *clnt = NULL; | |
367 | int ret = single_open(file, rpc_show_info, NULL); | |
368 | ||
369 | if (!ret) { | |
370 | struct seq_file *m = file->private_data; | |
371 | ||
372 | spin_lock(&file->f_path.dentry->d_lock); | |
373 | if (!d_unhashed(file->f_path.dentry)) | |
374 | clnt = RPC_I(inode)->private; | |
375 | if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) { | |
376 | spin_unlock(&file->f_path.dentry->d_lock); | |
377 | m->private = clnt; | |
378 | } else { | |
379 | spin_unlock(&file->f_path.dentry->d_lock); | |
380 | single_release(inode, file); | |
381 | ret = -EINVAL; | |
382 | } | |
383 | } | |
384 | return ret; | |
385 | } | |
386 | ||
387 | static int | |
388 | rpc_info_release(struct inode *inode, struct file *file) | |
389 | { | |
390 | struct seq_file *m = file->private_data; | |
391 | struct rpc_clnt *clnt = (struct rpc_clnt *)m->private; | |
392 | ||
393 | if (clnt) | |
394 | rpc_release_client(clnt); | |
395 | return single_release(inode, file); | |
396 | } | |
397 | ||
398 | static const struct file_operations rpc_info_operations = { | |
399 | .owner = THIS_MODULE, | |
400 | .open = rpc_info_open, | |
401 | .read = seq_read, | |
402 | .llseek = seq_lseek, | |
403 | .release = rpc_info_release, | |
404 | }; | |
405 | ||
406 | ||
407 | /* | |
408 | * Description of fs contents. | |
409 | */ | |
410 | struct rpc_filelist { | |
411 | const char *name; | |
412 | const struct file_operations *i_fop; | |
413 | umode_t mode; | |
414 | }; | |
415 | ||
416 | struct vfsmount *rpc_get_mount(void) | |
417 | { | |
418 | int err; | |
419 | ||
420 | err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mnt, &rpc_mount_count); | |
421 | if (err != 0) | |
422 | return ERR_PTR(err); | |
423 | return rpc_mnt; | |
424 | } | |
425 | EXPORT_SYMBOL_GPL(rpc_get_mount); | |
426 | ||
427 | void rpc_put_mount(void) | |
428 | { | |
429 | simple_release_fs(&rpc_mnt, &rpc_mount_count); | |
430 | } | |
431 | EXPORT_SYMBOL_GPL(rpc_put_mount); | |
432 | ||
433 | static int rpc_delete_dentry(struct dentry *dentry) | |
434 | { | |
435 | return 1; | |
436 | } | |
437 | ||
438 | static const struct dentry_operations rpc_dentry_operations = { | |
439 | .d_delete = rpc_delete_dentry, | |
440 | }; | |
441 | ||
442 | static struct inode * | |
443 | rpc_get_inode(struct super_block *sb, umode_t mode) | |
444 | { | |
445 | struct inode *inode = new_inode(sb); | |
446 | if (!inode) | |
447 | return NULL; | |
448 | inode->i_ino = get_next_ino(); | |
449 | inode->i_mode = mode; | |
450 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
451 | switch(mode & S_IFMT) { | |
452 | case S_IFDIR: | |
453 | inode->i_fop = &simple_dir_operations; | |
454 | inode->i_op = &simple_dir_inode_operations; | |
455 | inc_nlink(inode); | |
456 | default: | |
457 | break; | |
458 | } | |
459 | return inode; | |
460 | } | |
461 | ||
462 | static int __rpc_create_common(struct inode *dir, struct dentry *dentry, | |
463 | umode_t mode, | |
464 | const struct file_operations *i_fop, | |
465 | void *private) | |
466 | { | |
467 | struct inode *inode; | |
468 | ||
469 | BUG_ON(!d_unhashed(dentry)); | |
470 | inode = rpc_get_inode(dir->i_sb, mode); | |
471 | if (!inode) | |
472 | goto out_err; | |
473 | inode->i_ino = iunique(dir->i_sb, 100); | |
474 | if (i_fop) | |
475 | inode->i_fop = i_fop; | |
476 | if (private) | |
477 | rpc_inode_setowner(inode, private); | |
478 | d_add(dentry, inode); | |
479 | return 0; | |
480 | out_err: | |
481 | printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n", | |
482 | __FILE__, __func__, dentry->d_name.name); | |
483 | dput(dentry); | |
484 | return -ENOMEM; | |
485 | } | |
486 | ||
487 | static int __rpc_create(struct inode *dir, struct dentry *dentry, | |
488 | umode_t mode, | |
489 | const struct file_operations *i_fop, | |
490 | void *private) | |
491 | { | |
492 | int err; | |
493 | ||
494 | err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private); | |
495 | if (err) | |
496 | return err; | |
497 | fsnotify_create(dir, dentry); | |
498 | return 0; | |
499 | } | |
500 | ||
501 | static int __rpc_mkdir(struct inode *dir, struct dentry *dentry, | |
502 | umode_t mode, | |
503 | const struct file_operations *i_fop, | |
504 | void *private) | |
505 | { | |
506 | int err; | |
507 | ||
508 | err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private); | |
509 | if (err) | |
510 | return err; | |
511 | inc_nlink(dir); | |
512 | fsnotify_mkdir(dir, dentry); | |
513 | return 0; | |
514 | } | |
515 | ||
516 | static int __rpc_mkpipe(struct inode *dir, struct dentry *dentry, | |
517 | umode_t mode, | |
518 | const struct file_operations *i_fop, | |
519 | void *private, | |
520 | const struct rpc_pipe_ops *ops, | |
521 | int flags) | |
522 | { | |
523 | struct rpc_inode *rpci; | |
524 | int err; | |
525 | ||
526 | err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private); | |
527 | if (err) | |
528 | return err; | |
529 | rpci = RPC_I(dentry->d_inode); | |
530 | rpci->nkern_readwriters = 1; | |
531 | rpci->private = private; | |
532 | rpci->flags = flags; | |
533 | rpci->ops = ops; | |
534 | fsnotify_create(dir, dentry); | |
535 | return 0; | |
536 | } | |
537 | ||
538 | static int __rpc_rmdir(struct inode *dir, struct dentry *dentry) | |
539 | { | |
540 | int ret; | |
541 | ||
542 | dget(dentry); | |
543 | ret = simple_rmdir(dir, dentry); | |
544 | d_delete(dentry); | |
545 | dput(dentry); | |
546 | return ret; | |
547 | } | |
548 | ||
549 | static int __rpc_unlink(struct inode *dir, struct dentry *dentry) | |
550 | { | |
551 | int ret; | |
552 | ||
553 | dget(dentry); | |
554 | ret = simple_unlink(dir, dentry); | |
555 | d_delete(dentry); | |
556 | dput(dentry); | |
557 | return ret; | |
558 | } | |
559 | ||
560 | static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry) | |
561 | { | |
562 | struct inode *inode = dentry->d_inode; | |
563 | struct rpc_inode *rpci = RPC_I(inode); | |
564 | ||
565 | rpci->nkern_readwriters--; | |
566 | if (rpci->nkern_readwriters != 0) | |
567 | return 0; | |
568 | rpc_close_pipes(inode); | |
569 | return __rpc_unlink(dir, dentry); | |
570 | } | |
571 | ||
572 | static struct dentry *__rpc_lookup_create(struct dentry *parent, | |
573 | struct qstr *name) | |
574 | { | |
575 | struct dentry *dentry; | |
576 | ||
577 | dentry = d_lookup(parent, name); | |
578 | if (!dentry) { | |
579 | dentry = d_alloc(parent, name); | |
580 | if (!dentry) { | |
581 | dentry = ERR_PTR(-ENOMEM); | |
582 | goto out_err; | |
583 | } | |
584 | } | |
585 | if (!dentry->d_inode) | |
586 | dentry->d_op = &rpc_dentry_operations; | |
587 | out_err: | |
588 | return dentry; | |
589 | } | |
590 | ||
591 | static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent, | |
592 | struct qstr *name) | |
593 | { | |
594 | struct dentry *dentry; | |
595 | ||
596 | dentry = __rpc_lookup_create(parent, name); | |
597 | if (IS_ERR(dentry)) | |
598 | return dentry; | |
599 | if (dentry->d_inode == NULL) | |
600 | return dentry; | |
601 | dput(dentry); | |
602 | return ERR_PTR(-EEXIST); | |
603 | } | |
604 | ||
605 | /* | |
606 | * FIXME: This probably has races. | |
607 | */ | |
608 | static void __rpc_depopulate(struct dentry *parent, | |
609 | const struct rpc_filelist *files, | |
610 | int start, int eof) | |
611 | { | |
612 | struct inode *dir = parent->d_inode; | |
613 | struct dentry *dentry; | |
614 | struct qstr name; | |
615 | int i; | |
616 | ||
617 | for (i = start; i < eof; i++) { | |
618 | name.name = files[i].name; | |
619 | name.len = strlen(files[i].name); | |
620 | name.hash = full_name_hash(name.name, name.len); | |
621 | dentry = d_lookup(parent, &name); | |
622 | ||
623 | if (dentry == NULL) | |
624 | continue; | |
625 | if (dentry->d_inode == NULL) | |
626 | goto next; | |
627 | switch (dentry->d_inode->i_mode & S_IFMT) { | |
628 | default: | |
629 | BUG(); | |
630 | case S_IFREG: | |
631 | __rpc_unlink(dir, dentry); | |
632 | break; | |
633 | case S_IFDIR: | |
634 | __rpc_rmdir(dir, dentry); | |
635 | } | |
636 | next: | |
637 | dput(dentry); | |
638 | } | |
639 | } | |
640 | ||
641 | static void rpc_depopulate(struct dentry *parent, | |
642 | const struct rpc_filelist *files, | |
643 | int start, int eof) | |
644 | { | |
645 | struct inode *dir = parent->d_inode; | |
646 | ||
647 | mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD); | |
648 | __rpc_depopulate(parent, files, start, eof); | |
649 | mutex_unlock(&dir->i_mutex); | |
650 | } | |
651 | ||
652 | static int rpc_populate(struct dentry *parent, | |
653 | const struct rpc_filelist *files, | |
654 | int start, int eof, | |
655 | void *private) | |
656 | { | |
657 | struct inode *dir = parent->d_inode; | |
658 | struct dentry *dentry; | |
659 | int i, err; | |
660 | ||
661 | mutex_lock(&dir->i_mutex); | |
662 | for (i = start; i < eof; i++) { | |
663 | struct qstr q; | |
664 | ||
665 | q.name = files[i].name; | |
666 | q.len = strlen(files[i].name); | |
667 | q.hash = full_name_hash(q.name, q.len); | |
668 | dentry = __rpc_lookup_create_exclusive(parent, &q); | |
669 | err = PTR_ERR(dentry); | |
670 | if (IS_ERR(dentry)) | |
671 | goto out_bad; | |
672 | switch (files[i].mode & S_IFMT) { | |
673 | default: | |
674 | BUG(); | |
675 | case S_IFREG: | |
676 | err = __rpc_create(dir, dentry, | |
677 | files[i].mode, | |
678 | files[i].i_fop, | |
679 | private); | |
680 | break; | |
681 | case S_IFDIR: | |
682 | err = __rpc_mkdir(dir, dentry, | |
683 | files[i].mode, | |
684 | NULL, | |
685 | private); | |
686 | } | |
687 | if (err != 0) | |
688 | goto out_bad; | |
689 | } | |
690 | mutex_unlock(&dir->i_mutex); | |
691 | return 0; | |
692 | out_bad: | |
693 | __rpc_depopulate(parent, files, start, eof); | |
694 | mutex_unlock(&dir->i_mutex); | |
695 | printk(KERN_WARNING "%s: %s failed to populate directory %s\n", | |
696 | __FILE__, __func__, parent->d_name.name); | |
697 | return err; | |
698 | } | |
699 | ||
700 | static struct dentry *rpc_mkdir_populate(struct dentry *parent, | |
701 | struct qstr *name, umode_t mode, void *private, | |
702 | int (*populate)(struct dentry *, void *), void *args_populate) | |
703 | { | |
704 | struct dentry *dentry; | |
705 | struct inode *dir = parent->d_inode; | |
706 | int error; | |
707 | ||
708 | mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); | |
709 | dentry = __rpc_lookup_create_exclusive(parent, name); | |
710 | if (IS_ERR(dentry)) | |
711 | goto out; | |
712 | error = __rpc_mkdir(dir, dentry, mode, NULL, private); | |
713 | if (error != 0) | |
714 | goto out_err; | |
715 | if (populate != NULL) { | |
716 | error = populate(dentry, args_populate); | |
717 | if (error) | |
718 | goto err_rmdir; | |
719 | } | |
720 | out: | |
721 | mutex_unlock(&dir->i_mutex); | |
722 | return dentry; | |
723 | err_rmdir: | |
724 | __rpc_rmdir(dir, dentry); | |
725 | out_err: | |
726 | dentry = ERR_PTR(error); | |
727 | goto out; | |
728 | } | |
729 | ||
730 | static int rpc_rmdir_depopulate(struct dentry *dentry, | |
731 | void (*depopulate)(struct dentry *)) | |
732 | { | |
733 | struct dentry *parent; | |
734 | struct inode *dir; | |
735 | int error; | |
736 | ||
737 | parent = dget_parent(dentry); | |
738 | dir = parent->d_inode; | |
739 | mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); | |
740 | if (depopulate != NULL) | |
741 | depopulate(dentry); | |
742 | error = __rpc_rmdir(dir, dentry); | |
743 | mutex_unlock(&dir->i_mutex); | |
744 | dput(parent); | |
745 | return error; | |
746 | } | |
747 | ||
748 | /** | |
749 | * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication | |
750 | * @parent: dentry of directory to create new "pipe" in | |
751 | * @name: name of pipe | |
752 | * @private: private data to associate with the pipe, for the caller's use | |
753 | * @ops: operations defining the behavior of the pipe: upcall, downcall, | |
754 | * release_pipe, open_pipe, and destroy_msg. | |
755 | * @flags: rpc_inode flags | |
756 | * | |
757 | * Data is made available for userspace to read by calls to | |
758 | * rpc_queue_upcall(). The actual reads will result in calls to | |
759 | * @ops->upcall, which will be called with the file pointer, | |
760 | * message, and userspace buffer to copy to. | |
761 | * | |
762 | * Writes can come at any time, and do not necessarily have to be | |
763 | * responses to upcalls. They will result in calls to @msg->downcall. | |
764 | * | |
765 | * The @private argument passed here will be available to all these methods | |
766 | * from the file pointer, via RPC_I(file->f_dentry->d_inode)->private. | |
767 | */ | |
768 | struct dentry *rpc_mkpipe(struct dentry *parent, const char *name, | |
769 | void *private, const struct rpc_pipe_ops *ops, | |
770 | int flags) | |
771 | { | |
772 | struct dentry *dentry; | |
773 | struct inode *dir = parent->d_inode; | |
774 | umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR; | |
775 | struct qstr q; | |
776 | int err; | |
777 | ||
778 | if (ops->upcall == NULL) | |
779 | umode &= ~S_IRUGO; | |
780 | if (ops->downcall == NULL) | |
781 | umode &= ~S_IWUGO; | |
782 | ||
783 | q.name = name; | |
784 | q.len = strlen(name); | |
785 | q.hash = full_name_hash(q.name, q.len), | |
786 | ||
787 | mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); | |
788 | dentry = __rpc_lookup_create(parent, &q); | |
789 | if (IS_ERR(dentry)) | |
790 | goto out; | |
791 | if (dentry->d_inode) { | |
792 | struct rpc_inode *rpci = RPC_I(dentry->d_inode); | |
793 | if (rpci->private != private || | |
794 | rpci->ops != ops || | |
795 | rpci->flags != flags) { | |
796 | dput (dentry); | |
797 | err = -EBUSY; | |
798 | goto out_err; | |
799 | } | |
800 | rpci->nkern_readwriters++; | |
801 | goto out; | |
802 | } | |
803 | ||
804 | err = __rpc_mkpipe(dir, dentry, umode, &rpc_pipe_fops, | |
805 | private, ops, flags); | |
806 | if (err) | |
807 | goto out_err; | |
808 | out: | |
809 | mutex_unlock(&dir->i_mutex); | |
810 | return dentry; | |
811 | out_err: | |
812 | dentry = ERR_PTR(err); | |
813 | printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n", | |
814 | __FILE__, __func__, parent->d_name.name, name, | |
815 | err); | |
816 | goto out; | |
817 | } | |
818 | EXPORT_SYMBOL_GPL(rpc_mkpipe); | |
819 | ||
820 | /** | |
821 | * rpc_unlink - remove a pipe | |
822 | * @dentry: dentry for the pipe, as returned from rpc_mkpipe | |
823 | * | |
824 | * After this call, lookups will no longer find the pipe, and any | |
825 | * attempts to read or write using preexisting opens of the pipe will | |
826 | * return -EPIPE. | |
827 | */ | |
828 | int | |
829 | rpc_unlink(struct dentry *dentry) | |
830 | { | |
831 | struct dentry *parent; | |
832 | struct inode *dir; | |
833 | int error = 0; | |
834 | ||
835 | parent = dget_parent(dentry); | |
836 | dir = parent->d_inode; | |
837 | mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); | |
838 | error = __rpc_rmpipe(dir, dentry); | |
839 | mutex_unlock(&dir->i_mutex); | |
840 | dput(parent); | |
841 | return error; | |
842 | } | |
843 | EXPORT_SYMBOL_GPL(rpc_unlink); | |
844 | ||
845 | enum { | |
846 | RPCAUTH_info, | |
847 | RPCAUTH_EOF | |
848 | }; | |
849 | ||
850 | static const struct rpc_filelist authfiles[] = { | |
851 | [RPCAUTH_info] = { | |
852 | .name = "info", | |
853 | .i_fop = &rpc_info_operations, | |
854 | .mode = S_IFREG | S_IRUSR, | |
855 | }, | |
856 | }; | |
857 | ||
858 | static int rpc_clntdir_populate(struct dentry *dentry, void *private) | |
859 | { | |
860 | return rpc_populate(dentry, | |
861 | authfiles, RPCAUTH_info, RPCAUTH_EOF, | |
862 | private); | |
863 | } | |
864 | ||
865 | static void rpc_clntdir_depopulate(struct dentry *dentry) | |
866 | { | |
867 | rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF); | |
868 | } | |
869 | ||
870 | /** | |
871 | * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs | |
872 | * @dentry: dentry from the rpc_pipefs root to the new directory | |
873 | * @name: &struct qstr for the name | |
874 | * @rpc_client: rpc client to associate with this directory | |
875 | * | |
876 | * This creates a directory at the given @path associated with | |
877 | * @rpc_clnt, which will contain a file named "info" with some basic | |
878 | * information about the client, together with any "pipes" that may | |
879 | * later be created using rpc_mkpipe(). | |
880 | */ | |
881 | struct dentry *rpc_create_client_dir(struct dentry *dentry, | |
882 | struct qstr *name, | |
883 | struct rpc_clnt *rpc_client) | |
884 | { | |
885 | return rpc_mkdir_populate(dentry, name, S_IRUGO | S_IXUGO, NULL, | |
886 | rpc_clntdir_populate, rpc_client); | |
887 | } | |
888 | ||
889 | /** | |
890 | * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir() | |
891 | * @dentry: directory to remove | |
892 | */ | |
893 | int rpc_remove_client_dir(struct dentry *dentry) | |
894 | { | |
895 | return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate); | |
896 | } | |
897 | ||
898 | static const struct rpc_filelist cache_pipefs_files[3] = { | |
899 | [0] = { | |
900 | .name = "channel", | |
901 | .i_fop = &cache_file_operations_pipefs, | |
902 | .mode = S_IFREG|S_IRUSR|S_IWUSR, | |
903 | }, | |
904 | [1] = { | |
905 | .name = "content", | |
906 | .i_fop = &content_file_operations_pipefs, | |
907 | .mode = S_IFREG|S_IRUSR, | |
908 | }, | |
909 | [2] = { | |
910 | .name = "flush", | |
911 | .i_fop = &cache_flush_operations_pipefs, | |
912 | .mode = S_IFREG|S_IRUSR|S_IWUSR, | |
913 | }, | |
914 | }; | |
915 | ||
916 | static int rpc_cachedir_populate(struct dentry *dentry, void *private) | |
917 | { | |
918 | return rpc_populate(dentry, | |
919 | cache_pipefs_files, 0, 3, | |
920 | private); | |
921 | } | |
922 | ||
923 | static void rpc_cachedir_depopulate(struct dentry *dentry) | |
924 | { | |
925 | rpc_depopulate(dentry, cache_pipefs_files, 0, 3); | |
926 | } | |
927 | ||
928 | struct dentry *rpc_create_cache_dir(struct dentry *parent, struct qstr *name, | |
929 | mode_t umode, struct cache_detail *cd) | |
930 | { | |
931 | return rpc_mkdir_populate(parent, name, umode, NULL, | |
932 | rpc_cachedir_populate, cd); | |
933 | } | |
934 | ||
935 | void rpc_remove_cache_dir(struct dentry *dentry) | |
936 | { | |
937 | rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate); | |
938 | } | |
939 | ||
940 | /* | |
941 | * populate the filesystem | |
942 | */ | |
943 | static const struct super_operations s_ops = { | |
944 | .alloc_inode = rpc_alloc_inode, | |
945 | .destroy_inode = rpc_destroy_inode, | |
946 | .statfs = simple_statfs, | |
947 | }; | |
948 | ||
949 | #define RPCAUTH_GSSMAGIC 0x67596969 | |
950 | ||
951 | /* | |
952 | * We have a single directory with 1 node in it. | |
953 | */ | |
954 | enum { | |
955 | RPCAUTH_lockd, | |
956 | RPCAUTH_mount, | |
957 | RPCAUTH_nfs, | |
958 | RPCAUTH_portmap, | |
959 | RPCAUTH_statd, | |
960 | RPCAUTH_nfsd4_cb, | |
961 | RPCAUTH_cache, | |
962 | RPCAUTH_RootEOF | |
963 | }; | |
964 | ||
965 | static const struct rpc_filelist files[] = { | |
966 | [RPCAUTH_lockd] = { | |
967 | .name = "lockd", | |
968 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, | |
969 | }, | |
970 | [RPCAUTH_mount] = { | |
971 | .name = "mount", | |
972 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, | |
973 | }, | |
974 | [RPCAUTH_nfs] = { | |
975 | .name = "nfs", | |
976 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, | |
977 | }, | |
978 | [RPCAUTH_portmap] = { | |
979 | .name = "portmap", | |
980 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, | |
981 | }, | |
982 | [RPCAUTH_statd] = { | |
983 | .name = "statd", | |
984 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, | |
985 | }, | |
986 | [RPCAUTH_nfsd4_cb] = { | |
987 | .name = "nfsd4_cb", | |
988 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, | |
989 | }, | |
990 | [RPCAUTH_cache] = { | |
991 | .name = "cache", | |
992 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, | |
993 | }, | |
994 | }; | |
995 | ||
996 | static int | |
997 | rpc_fill_super(struct super_block *sb, void *data, int silent) | |
998 | { | |
999 | struct inode *inode; | |
1000 | struct dentry *root; | |
1001 | ||
1002 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
1003 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
1004 | sb->s_magic = RPCAUTH_GSSMAGIC; | |
1005 | sb->s_op = &s_ops; | |
1006 | sb->s_time_gran = 1; | |
1007 | ||
1008 | inode = rpc_get_inode(sb, S_IFDIR | 0755); | |
1009 | if (!inode) | |
1010 | return -ENOMEM; | |
1011 | sb->s_root = root = d_alloc_root(inode); | |
1012 | if (!root) { | |
1013 | iput(inode); | |
1014 | return -ENOMEM; | |
1015 | } | |
1016 | if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL)) | |
1017 | return -ENOMEM; | |
1018 | return 0; | |
1019 | } | |
1020 | ||
1021 | static struct dentry * | |
1022 | rpc_mount(struct file_system_type *fs_type, | |
1023 | int flags, const char *dev_name, void *data) | |
1024 | { | |
1025 | return mount_single(fs_type, flags, data, rpc_fill_super); | |
1026 | } | |
1027 | ||
1028 | static struct file_system_type rpc_pipe_fs_type = { | |
1029 | .owner = THIS_MODULE, | |
1030 | .name = "rpc_pipefs", | |
1031 | .mount = rpc_mount, | |
1032 | .kill_sb = kill_litter_super, | |
1033 | }; | |
1034 | ||
1035 | static void | |
1036 | init_once(void *foo) | |
1037 | { | |
1038 | struct rpc_inode *rpci = (struct rpc_inode *) foo; | |
1039 | ||
1040 | inode_init_once(&rpci->vfs_inode); | |
1041 | rpci->private = NULL; | |
1042 | rpci->nreaders = 0; | |
1043 | rpci->nwriters = 0; | |
1044 | INIT_LIST_HEAD(&rpci->in_upcall); | |
1045 | INIT_LIST_HEAD(&rpci->in_downcall); | |
1046 | INIT_LIST_HEAD(&rpci->pipe); | |
1047 | rpci->pipelen = 0; | |
1048 | init_waitqueue_head(&rpci->waitq); | |
1049 | INIT_DELAYED_WORK(&rpci->queue_timeout, | |
1050 | rpc_timeout_upcall_queue); | |
1051 | rpci->ops = NULL; | |
1052 | } | |
1053 | ||
1054 | int register_rpc_pipefs(void) | |
1055 | { | |
1056 | int err; | |
1057 | ||
1058 | rpc_inode_cachep = kmem_cache_create("rpc_inode_cache", | |
1059 | sizeof(struct rpc_inode), | |
1060 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| | |
1061 | SLAB_MEM_SPREAD), | |
1062 | init_once); | |
1063 | if (!rpc_inode_cachep) | |
1064 | return -ENOMEM; | |
1065 | err = register_filesystem(&rpc_pipe_fs_type); | |
1066 | if (err) { | |
1067 | kmem_cache_destroy(rpc_inode_cachep); | |
1068 | return err; | |
1069 | } | |
1070 | ||
1071 | return 0; | |
1072 | } | |
1073 | ||
1074 | void unregister_rpc_pipefs(void) | |
1075 | { | |
1076 | kmem_cache_destroy(rpc_inode_cachep); | |
1077 | unregister_filesystem(&rpc_pipe_fs_type); | |
1078 | } |