Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * POSIX message queues filesystem for Linux. | |
3 | * | |
4 | * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl) | |
5 | * Michal Wronski (wrona@mat.uni.torun.pl) | |
6 | * | |
7 | * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com) | |
8 | * Lockless receive & send, fd based notify: | |
9 | * Manfred Spraul (manfred@colorfullife.com) | |
10 | * | |
11 | * This file is released under the GPL. | |
12 | */ | |
13 | ||
14 | #include <linux/init.h> | |
15 | #include <linux/pagemap.h> | |
16 | #include <linux/file.h> | |
17 | #include <linux/mount.h> | |
18 | #include <linux/namei.h> | |
19 | #include <linux/sysctl.h> | |
20 | #include <linux/poll.h> | |
21 | #include <linux/mqueue.h> | |
22 | #include <linux/msg.h> | |
23 | #include <linux/skbuff.h> | |
24 | #include <linux/netlink.h> | |
25 | #include <linux/syscalls.h> | |
7ed20e1a | 26 | #include <linux/signal.h> |
1da177e4 LT |
27 | #include <net/sock.h> |
28 | #include "util.h" | |
29 | ||
30 | #define MQUEUE_MAGIC 0x19800202 | |
31 | #define DIRENT_SIZE 20 | |
32 | #define FILENT_SIZE 80 | |
33 | ||
34 | #define SEND 0 | |
35 | #define RECV 1 | |
36 | ||
37 | #define STATE_NONE 0 | |
38 | #define STATE_PENDING 1 | |
39 | #define STATE_READY 2 | |
40 | ||
41 | /* used by sysctl */ | |
42 | #define FS_MQUEUE 1 | |
43 | #define CTL_QUEUESMAX 2 | |
44 | #define CTL_MSGMAX 3 | |
45 | #define CTL_MSGSIZEMAX 4 | |
46 | ||
47 | /* default values */ | |
48 | #define DFLT_QUEUESMAX 256 /* max number of message queues */ | |
49 | #define DFLT_MSGMAX 10 /* max number of messages in each queue */ | |
50 | #define HARD_MSGMAX (131072/sizeof(void*)) | |
51 | #define DFLT_MSGSIZEMAX 8192 /* max message size */ | |
52 | ||
53 | #define NOTIFY_COOKIE_LEN 32 | |
54 | ||
55 | struct ext_wait_queue { /* queue of sleeping tasks */ | |
56 | struct task_struct *task; | |
57 | struct list_head list; | |
58 | struct msg_msg *msg; /* ptr of loaded message */ | |
59 | int state; /* one of STATE_* values */ | |
60 | }; | |
61 | ||
62 | struct mqueue_inode_info { | |
63 | spinlock_t lock; | |
64 | struct inode vfs_inode; | |
65 | wait_queue_head_t wait_q; | |
66 | ||
67 | struct msg_msg **messages; | |
68 | struct mq_attr attr; | |
69 | ||
70 | struct sigevent notify; | |
71 | pid_t notify_owner; | |
338cec32 | 72 | struct user_struct *user; /* user who created, for accounting */ |
1da177e4 LT |
73 | struct sock *notify_sock; |
74 | struct sk_buff *notify_cookie; | |
75 | ||
76 | /* for tasks waiting for free space and messages, respectively */ | |
77 | struct ext_wait_queue e_wait_q[2]; | |
78 | ||
79 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ | |
80 | }; | |
81 | ||
82 | static struct inode_operations mqueue_dir_inode_operations; | |
83 | static struct file_operations mqueue_file_operations; | |
84 | static struct super_operations mqueue_super_ops; | |
85 | static void remove_notification(struct mqueue_inode_info *info); | |
86 | ||
87 | static spinlock_t mq_lock; | |
88 | static kmem_cache_t *mqueue_inode_cachep; | |
89 | static struct vfsmount *mqueue_mnt; | |
90 | ||
91 | static unsigned int queues_count; | |
92 | static unsigned int queues_max = DFLT_QUEUESMAX; | |
93 | static unsigned int msg_max = DFLT_MSGMAX; | |
94 | static unsigned int msgsize_max = DFLT_MSGSIZEMAX; | |
95 | ||
96 | static struct ctl_table_header * mq_sysctl_table; | |
97 | ||
98 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) | |
99 | { | |
100 | return container_of(inode, struct mqueue_inode_info, vfs_inode); | |
101 | } | |
102 | ||
103 | static struct inode *mqueue_get_inode(struct super_block *sb, int mode, | |
104 | struct mq_attr *attr) | |
105 | { | |
106 | struct inode *inode; | |
107 | ||
108 | inode = new_inode(sb); | |
109 | if (inode) { | |
110 | inode->i_mode = mode; | |
111 | inode->i_uid = current->fsuid; | |
112 | inode->i_gid = current->fsgid; | |
113 | inode->i_blksize = PAGE_CACHE_SIZE; | |
114 | inode->i_blocks = 0; | |
115 | inode->i_mtime = inode->i_ctime = inode->i_atime = | |
116 | CURRENT_TIME; | |
117 | ||
118 | if (S_ISREG(mode)) { | |
119 | struct mqueue_inode_info *info; | |
120 | struct task_struct *p = current; | |
121 | struct user_struct *u = p->user; | |
122 | unsigned long mq_bytes, mq_msg_tblsz; | |
123 | ||
124 | inode->i_fop = &mqueue_file_operations; | |
125 | inode->i_size = FILENT_SIZE; | |
126 | /* mqueue specific info */ | |
127 | info = MQUEUE_I(inode); | |
128 | spin_lock_init(&info->lock); | |
129 | init_waitqueue_head(&info->wait_q); | |
130 | INIT_LIST_HEAD(&info->e_wait_q[0].list); | |
131 | INIT_LIST_HEAD(&info->e_wait_q[1].list); | |
132 | info->messages = NULL; | |
133 | info->notify_owner = 0; | |
134 | info->qsize = 0; | |
135 | info->user = NULL; /* set when all is ok */ | |
136 | memset(&info->attr, 0, sizeof(info->attr)); | |
137 | info->attr.mq_maxmsg = DFLT_MSGMAX; | |
138 | info->attr.mq_msgsize = DFLT_MSGSIZEMAX; | |
139 | if (attr) { | |
140 | info->attr.mq_maxmsg = attr->mq_maxmsg; | |
141 | info->attr.mq_msgsize = attr->mq_msgsize; | |
142 | } | |
143 | mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *); | |
144 | mq_bytes = (mq_msg_tblsz + | |
145 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
146 | ||
147 | spin_lock(&mq_lock); | |
148 | if (u->mq_bytes + mq_bytes < u->mq_bytes || | |
149 | u->mq_bytes + mq_bytes > | |
150 | p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) { | |
151 | spin_unlock(&mq_lock); | |
152 | goto out_inode; | |
153 | } | |
154 | u->mq_bytes += mq_bytes; | |
155 | spin_unlock(&mq_lock); | |
156 | ||
157 | info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL); | |
158 | if (!info->messages) { | |
159 | spin_lock(&mq_lock); | |
160 | u->mq_bytes -= mq_bytes; | |
161 | spin_unlock(&mq_lock); | |
162 | goto out_inode; | |
163 | } | |
164 | /* all is ok */ | |
165 | info->user = get_uid(u); | |
166 | } else if (S_ISDIR(mode)) { | |
167 | inode->i_nlink++; | |
168 | /* Some things misbehave if size == 0 on a directory */ | |
169 | inode->i_size = 2 * DIRENT_SIZE; | |
170 | inode->i_op = &mqueue_dir_inode_operations; | |
171 | inode->i_fop = &simple_dir_operations; | |
172 | } | |
173 | } | |
174 | return inode; | |
175 | out_inode: | |
176 | make_bad_inode(inode); | |
177 | iput(inode); | |
178 | return NULL; | |
179 | } | |
180 | ||
181 | static int mqueue_fill_super(struct super_block *sb, void *data, int silent) | |
182 | { | |
183 | struct inode *inode; | |
184 | ||
185 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
186 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
187 | sb->s_magic = MQUEUE_MAGIC; | |
188 | sb->s_op = &mqueue_super_ops; | |
189 | ||
190 | inode = mqueue_get_inode(sb, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); | |
191 | if (!inode) | |
192 | return -ENOMEM; | |
193 | ||
194 | sb->s_root = d_alloc_root(inode); | |
195 | if (!sb->s_root) { | |
196 | iput(inode); | |
197 | return -ENOMEM; | |
198 | } | |
199 | ||
200 | return 0; | |
201 | } | |
202 | ||
203 | static struct super_block *mqueue_get_sb(struct file_system_type *fs_type, | |
204 | int flags, const char *dev_name, | |
205 | void *data) | |
206 | { | |
207 | return get_sb_single(fs_type, flags, data, mqueue_fill_super); | |
208 | } | |
209 | ||
210 | static void init_once(void *foo, kmem_cache_t * cachep, unsigned long flags) | |
211 | { | |
212 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; | |
213 | ||
214 | if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) == | |
215 | SLAB_CTOR_CONSTRUCTOR) | |
216 | inode_init_once(&p->vfs_inode); | |
217 | } | |
218 | ||
219 | static struct inode *mqueue_alloc_inode(struct super_block *sb) | |
220 | { | |
221 | struct mqueue_inode_info *ei; | |
222 | ||
223 | ei = kmem_cache_alloc(mqueue_inode_cachep, SLAB_KERNEL); | |
224 | if (!ei) | |
225 | return NULL; | |
226 | return &ei->vfs_inode; | |
227 | } | |
228 | ||
229 | static void mqueue_destroy_inode(struct inode *inode) | |
230 | { | |
231 | kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); | |
232 | } | |
233 | ||
234 | static void mqueue_delete_inode(struct inode *inode) | |
235 | { | |
236 | struct mqueue_inode_info *info; | |
237 | struct user_struct *user; | |
238 | unsigned long mq_bytes; | |
239 | int i; | |
240 | ||
241 | if (S_ISDIR(inode->i_mode)) { | |
242 | clear_inode(inode); | |
243 | return; | |
244 | } | |
245 | info = MQUEUE_I(inode); | |
246 | spin_lock(&info->lock); | |
247 | for (i = 0; i < info->attr.mq_curmsgs; i++) | |
248 | free_msg(info->messages[i]); | |
249 | kfree(info->messages); | |
250 | spin_unlock(&info->lock); | |
251 | ||
252 | clear_inode(inode); | |
253 | ||
254 | mq_bytes = (info->attr.mq_maxmsg * sizeof(struct msg_msg *) + | |
255 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
256 | user = info->user; | |
257 | if (user) { | |
258 | spin_lock(&mq_lock); | |
259 | user->mq_bytes -= mq_bytes; | |
260 | queues_count--; | |
261 | spin_unlock(&mq_lock); | |
262 | free_uid(user); | |
263 | } | |
264 | } | |
265 | ||
266 | static int mqueue_create(struct inode *dir, struct dentry *dentry, | |
267 | int mode, struct nameidata *nd) | |
268 | { | |
269 | struct inode *inode; | |
270 | struct mq_attr *attr = dentry->d_fsdata; | |
271 | int error; | |
272 | ||
273 | spin_lock(&mq_lock); | |
274 | if (queues_count >= queues_max && !capable(CAP_SYS_RESOURCE)) { | |
275 | error = -ENOSPC; | |
276 | goto out_lock; | |
277 | } | |
278 | queues_count++; | |
279 | spin_unlock(&mq_lock); | |
280 | ||
281 | inode = mqueue_get_inode(dir->i_sb, mode, attr); | |
282 | if (!inode) { | |
283 | error = -ENOMEM; | |
284 | spin_lock(&mq_lock); | |
285 | queues_count--; | |
286 | goto out_lock; | |
287 | } | |
288 | ||
289 | dir->i_size += DIRENT_SIZE; | |
290 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
291 | ||
292 | d_instantiate(dentry, inode); | |
293 | dget(dentry); | |
294 | return 0; | |
295 | out_lock: | |
296 | spin_unlock(&mq_lock); | |
297 | return error; | |
298 | } | |
299 | ||
300 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) | |
301 | { | |
302 | struct inode *inode = dentry->d_inode; | |
303 | ||
304 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
305 | dir->i_size -= DIRENT_SIZE; | |
306 | inode->i_nlink--; | |
307 | dput(dentry); | |
308 | return 0; | |
309 | } | |
310 | ||
311 | /* | |
312 | * This is routine for system read from queue file. | |
313 | * To avoid mess with doing here some sort of mq_receive we allow | |
314 | * to read only queue size & notification info (the only values | |
315 | * that are interesting from user point of view and aren't accessible | |
316 | * through std routines) | |
317 | */ | |
318 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, | |
319 | size_t count, loff_t * off) | |
320 | { | |
321 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode); | |
322 | char buffer[FILENT_SIZE]; | |
323 | size_t slen; | |
324 | loff_t o; | |
325 | ||
326 | if (!count) | |
327 | return 0; | |
328 | ||
329 | spin_lock(&info->lock); | |
330 | snprintf(buffer, sizeof(buffer), | |
331 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", | |
332 | info->qsize, | |
333 | info->notify_owner ? info->notify.sigev_notify : 0, | |
334 | (info->notify_owner && | |
335 | info->notify.sigev_notify == SIGEV_SIGNAL) ? | |
336 | info->notify.sigev_signo : 0, | |
337 | info->notify_owner); | |
338 | spin_unlock(&info->lock); | |
339 | buffer[sizeof(buffer)-1] = '\0'; | |
340 | slen = strlen(buffer)+1; | |
341 | ||
342 | o = *off; | |
343 | if (o > slen) | |
344 | return 0; | |
345 | ||
346 | if (o + count > slen) | |
347 | count = slen - o; | |
348 | ||
349 | if (copy_to_user(u_data, buffer + o, count)) | |
350 | return -EFAULT; | |
351 | ||
352 | *off = o + count; | |
353 | filp->f_dentry->d_inode->i_atime = filp->f_dentry->d_inode->i_ctime = CURRENT_TIME; | |
354 | return count; | |
355 | } | |
356 | ||
357 | static int mqueue_flush_file(struct file *filp) | |
358 | { | |
359 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode); | |
360 | ||
361 | spin_lock(&info->lock); | |
362 | if (current->tgid == info->notify_owner) | |
363 | remove_notification(info); | |
364 | ||
365 | spin_unlock(&info->lock); | |
366 | return 0; | |
367 | } | |
368 | ||
369 | static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) | |
370 | { | |
371 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode); | |
372 | int retval = 0; | |
373 | ||
374 | poll_wait(filp, &info->wait_q, poll_tab); | |
375 | ||
376 | spin_lock(&info->lock); | |
377 | if (info->attr.mq_curmsgs) | |
378 | retval = POLLIN | POLLRDNORM; | |
379 | ||
380 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) | |
381 | retval |= POLLOUT | POLLWRNORM; | |
382 | spin_unlock(&info->lock); | |
383 | ||
384 | return retval; | |
385 | } | |
386 | ||
387 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ | |
388 | static void wq_add(struct mqueue_inode_info *info, int sr, | |
389 | struct ext_wait_queue *ewp) | |
390 | { | |
391 | struct ext_wait_queue *walk; | |
392 | ||
393 | ewp->task = current; | |
394 | ||
395 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { | |
396 | if (walk->task->static_prio <= current->static_prio) { | |
397 | list_add_tail(&ewp->list, &walk->list); | |
398 | return; | |
399 | } | |
400 | } | |
401 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); | |
402 | } | |
403 | ||
404 | /* | |
405 | * Puts current task to sleep. Caller must hold queue lock. After return | |
406 | * lock isn't held. | |
407 | * sr: SEND or RECV | |
408 | */ | |
409 | static int wq_sleep(struct mqueue_inode_info *info, int sr, | |
410 | long timeout, struct ext_wait_queue *ewp) | |
411 | { | |
412 | int retval; | |
413 | signed long time; | |
414 | ||
415 | wq_add(info, sr, ewp); | |
416 | ||
417 | for (;;) { | |
418 | set_current_state(TASK_INTERRUPTIBLE); | |
419 | ||
420 | spin_unlock(&info->lock); | |
421 | time = schedule_timeout(timeout); | |
422 | ||
423 | while (ewp->state == STATE_PENDING) | |
424 | cpu_relax(); | |
425 | ||
426 | if (ewp->state == STATE_READY) { | |
427 | retval = 0; | |
428 | goto out; | |
429 | } | |
430 | spin_lock(&info->lock); | |
431 | if (ewp->state == STATE_READY) { | |
432 | retval = 0; | |
433 | goto out_unlock; | |
434 | } | |
435 | if (signal_pending(current)) { | |
436 | retval = -ERESTARTSYS; | |
437 | break; | |
438 | } | |
439 | if (time == 0) { | |
440 | retval = -ETIMEDOUT; | |
441 | break; | |
442 | } | |
443 | } | |
444 | list_del(&ewp->list); | |
445 | out_unlock: | |
446 | spin_unlock(&info->lock); | |
447 | out: | |
448 | return retval; | |
449 | } | |
450 | ||
451 | /* | |
452 | * Returns waiting task that should be serviced first or NULL if none exists | |
453 | */ | |
454 | static struct ext_wait_queue *wq_get_first_waiter( | |
455 | struct mqueue_inode_info *info, int sr) | |
456 | { | |
457 | struct list_head *ptr; | |
458 | ||
459 | ptr = info->e_wait_q[sr].list.prev; | |
460 | if (ptr == &info->e_wait_q[sr].list) | |
461 | return NULL; | |
462 | return list_entry(ptr, struct ext_wait_queue, list); | |
463 | } | |
464 | ||
465 | /* Auxiliary functions to manipulate messages' list */ | |
466 | static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info) | |
467 | { | |
468 | int k; | |
469 | ||
470 | k = info->attr.mq_curmsgs - 1; | |
471 | while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) { | |
472 | info->messages[k + 1] = info->messages[k]; | |
473 | k--; | |
474 | } | |
475 | info->attr.mq_curmsgs++; | |
476 | info->qsize += ptr->m_ts; | |
477 | info->messages[k + 1] = ptr; | |
478 | } | |
479 | ||
480 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) | |
481 | { | |
482 | info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts; | |
483 | return info->messages[info->attr.mq_curmsgs]; | |
484 | } | |
485 | ||
486 | static inline void set_cookie(struct sk_buff *skb, char code) | |
487 | { | |
488 | ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; | |
489 | } | |
490 | ||
491 | /* | |
492 | * The next function is only to split too long sys_mq_timedsend | |
493 | */ | |
494 | static void __do_notify(struct mqueue_inode_info *info) | |
495 | { | |
496 | /* notification | |
497 | * invoked when there is registered process and there isn't process | |
498 | * waiting synchronously for message AND state of queue changed from | |
499 | * empty to not empty. Here we are sure that no one is waiting | |
500 | * synchronously. */ | |
501 | if (info->notify_owner && | |
502 | info->attr.mq_curmsgs == 1) { | |
503 | struct siginfo sig_i; | |
504 | switch (info->notify.sigev_notify) { | |
505 | case SIGEV_NONE: | |
506 | break; | |
507 | case SIGEV_SIGNAL: | |
508 | /* sends signal */ | |
509 | ||
510 | sig_i.si_signo = info->notify.sigev_signo; | |
511 | sig_i.si_errno = 0; | |
512 | sig_i.si_code = SI_MESGQ; | |
513 | sig_i.si_value = info->notify.sigev_value; | |
514 | sig_i.si_pid = current->tgid; | |
515 | sig_i.si_uid = current->uid; | |
516 | ||
517 | kill_proc_info(info->notify.sigev_signo, | |
518 | &sig_i, info->notify_owner); | |
519 | break; | |
520 | case SIGEV_THREAD: | |
521 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); | |
522 | netlink_sendskb(info->notify_sock, | |
523 | info->notify_cookie, 0); | |
524 | break; | |
525 | } | |
526 | /* after notification unregisters process */ | |
527 | info->notify_owner = 0; | |
528 | } | |
529 | wake_up(&info->wait_q); | |
530 | } | |
531 | ||
532 | static long prepare_timeout(const struct timespec __user *u_arg) | |
533 | { | |
534 | struct timespec ts, nowts; | |
535 | long timeout; | |
536 | ||
537 | if (u_arg) { | |
538 | if (unlikely(copy_from_user(&ts, u_arg, | |
539 | sizeof(struct timespec)))) | |
540 | return -EFAULT; | |
541 | ||
542 | if (unlikely(ts.tv_nsec < 0 || ts.tv_sec < 0 | |
543 | || ts.tv_nsec >= NSEC_PER_SEC)) | |
544 | return -EINVAL; | |
545 | nowts = CURRENT_TIME; | |
546 | /* first subtract as jiffies can't be too big */ | |
547 | ts.tv_sec -= nowts.tv_sec; | |
548 | if (ts.tv_nsec < nowts.tv_nsec) { | |
549 | ts.tv_nsec += NSEC_PER_SEC; | |
550 | ts.tv_sec--; | |
551 | } | |
552 | ts.tv_nsec -= nowts.tv_nsec; | |
553 | if (ts.tv_sec < 0) | |
554 | return 0; | |
555 | ||
556 | timeout = timespec_to_jiffies(&ts) + 1; | |
557 | } else | |
558 | return MAX_SCHEDULE_TIMEOUT; | |
559 | ||
560 | return timeout; | |
561 | } | |
562 | ||
563 | static void remove_notification(struct mqueue_inode_info *info) | |
564 | { | |
565 | if (info->notify_owner != 0 && | |
566 | info->notify.sigev_notify == SIGEV_THREAD) { | |
567 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); | |
568 | netlink_sendskb(info->notify_sock, info->notify_cookie, 0); | |
569 | } | |
570 | info->notify_owner = 0; | |
571 | } | |
572 | ||
573 | static int mq_attr_ok(struct mq_attr *attr) | |
574 | { | |
575 | if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) | |
576 | return 0; | |
577 | if (capable(CAP_SYS_RESOURCE)) { | |
578 | if (attr->mq_maxmsg > HARD_MSGMAX) | |
579 | return 0; | |
580 | } else { | |
581 | if (attr->mq_maxmsg > msg_max || | |
582 | attr->mq_msgsize > msgsize_max) | |
583 | return 0; | |
584 | } | |
585 | /* check for overflow */ | |
586 | if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) | |
587 | return 0; | |
588 | if ((unsigned long)(attr->mq_maxmsg * attr->mq_msgsize) + | |
589 | (attr->mq_maxmsg * sizeof (struct msg_msg *)) < | |
590 | (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize)) | |
591 | return 0; | |
592 | return 1; | |
593 | } | |
594 | ||
595 | /* | |
596 | * Invoked when creating a new queue via sys_mq_open | |
597 | */ | |
598 | static struct file *do_create(struct dentry *dir, struct dentry *dentry, | |
599 | int oflag, mode_t mode, struct mq_attr __user *u_attr) | |
600 | { | |
601 | struct file *filp; | |
602 | struct mq_attr attr; | |
603 | int ret; | |
604 | ||
605 | if (u_attr != NULL) { | |
606 | if (copy_from_user(&attr, u_attr, sizeof(attr))) | |
607 | return ERR_PTR(-EFAULT); | |
608 | if (!mq_attr_ok(&attr)) | |
609 | return ERR_PTR(-EINVAL); | |
610 | /* store for use during create */ | |
611 | dentry->d_fsdata = &attr; | |
612 | } | |
613 | ||
59175839 | 614 | mode &= ~current->fs->umask; |
1da177e4 LT |
615 | ret = vfs_create(dir->d_inode, dentry, mode, NULL); |
616 | dentry->d_fsdata = NULL; | |
617 | if (ret) | |
618 | return ERR_PTR(ret); | |
619 | ||
620 | filp = dentry_open(dentry, mqueue_mnt, oflag); | |
621 | if (!IS_ERR(filp)) | |
622 | dget(dentry); | |
623 | ||
624 | return filp; | |
625 | } | |
626 | ||
627 | /* Opens existing queue */ | |
628 | static struct file *do_open(struct dentry *dentry, int oflag) | |
629 | { | |
630 | static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, | |
631 | MAY_READ | MAY_WRITE }; | |
632 | struct file *filp; | |
633 | ||
634 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) | |
635 | return ERR_PTR(-EINVAL); | |
636 | ||
637 | if (permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE], NULL)) | |
638 | return ERR_PTR(-EACCES); | |
639 | ||
640 | filp = dentry_open(dentry, mqueue_mnt, oflag); | |
641 | ||
642 | if (!IS_ERR(filp)) | |
643 | dget(dentry); | |
644 | ||
645 | return filp; | |
646 | } | |
647 | ||
648 | asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode, | |
649 | struct mq_attr __user *u_attr) | |
650 | { | |
651 | struct dentry *dentry; | |
652 | struct file *filp; | |
653 | char *name; | |
654 | int fd, error; | |
655 | ||
656 | if (IS_ERR(name = getname(u_name))) | |
657 | return PTR_ERR(name); | |
658 | ||
659 | fd = get_unused_fd(); | |
660 | if (fd < 0) | |
661 | goto out_putname; | |
662 | ||
663 | down(&mqueue_mnt->mnt_root->d_inode->i_sem); | |
664 | dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name)); | |
665 | if (IS_ERR(dentry)) { | |
666 | error = PTR_ERR(dentry); | |
667 | goto out_err; | |
668 | } | |
669 | mntget(mqueue_mnt); | |
670 | ||
671 | if (oflag & O_CREAT) { | |
672 | if (dentry->d_inode) { /* entry already exists */ | |
673 | filp = (oflag & O_EXCL) ? ERR_PTR(-EEXIST) : | |
674 | do_open(dentry, oflag); | |
675 | } else { | |
676 | filp = do_create(mqueue_mnt->mnt_root, dentry, | |
677 | oflag, mode, u_attr); | |
678 | } | |
679 | } else | |
680 | filp = (dentry->d_inode) ? do_open(dentry, oflag) : | |
681 | ERR_PTR(-ENOENT); | |
682 | ||
683 | dput(dentry); | |
684 | ||
685 | if (IS_ERR(filp)) { | |
686 | error = PTR_ERR(filp); | |
687 | goto out_putfd; | |
688 | } | |
689 | ||
690 | set_close_on_exec(fd, 1); | |
691 | fd_install(fd, filp); | |
692 | goto out_upsem; | |
693 | ||
694 | out_putfd: | |
695 | mntput(mqueue_mnt); | |
696 | put_unused_fd(fd); | |
697 | out_err: | |
698 | fd = error; | |
699 | out_upsem: | |
700 | up(&mqueue_mnt->mnt_root->d_inode->i_sem); | |
701 | out_putname: | |
702 | putname(name); | |
703 | return fd; | |
704 | } | |
705 | ||
706 | asmlinkage long sys_mq_unlink(const char __user *u_name) | |
707 | { | |
708 | int err; | |
709 | char *name; | |
710 | struct dentry *dentry; | |
711 | struct inode *inode = NULL; | |
712 | ||
713 | name = getname(u_name); | |
714 | if (IS_ERR(name)) | |
715 | return PTR_ERR(name); | |
716 | ||
717 | down(&mqueue_mnt->mnt_root->d_inode->i_sem); | |
718 | dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name)); | |
719 | if (IS_ERR(dentry)) { | |
720 | err = PTR_ERR(dentry); | |
721 | goto out_unlock; | |
722 | } | |
723 | ||
724 | if (!dentry->d_inode) { | |
725 | err = -ENOENT; | |
726 | goto out_err; | |
727 | } | |
728 | ||
729 | inode = dentry->d_inode; | |
730 | if (inode) | |
731 | atomic_inc(&inode->i_count); | |
732 | ||
733 | err = vfs_unlink(dentry->d_parent->d_inode, dentry); | |
734 | out_err: | |
735 | dput(dentry); | |
736 | ||
737 | out_unlock: | |
738 | up(&mqueue_mnt->mnt_root->d_inode->i_sem); | |
739 | putname(name); | |
740 | if (inode) | |
741 | iput(inode); | |
742 | ||
743 | return err; | |
744 | } | |
745 | ||
746 | /* Pipelined send and receive functions. | |
747 | * | |
748 | * If a receiver finds no waiting message, then it registers itself in the | |
749 | * list of waiting receivers. A sender checks that list before adding the new | |
750 | * message into the message array. If there is a waiting receiver, then it | |
751 | * bypasses the message array and directly hands the message over to the | |
752 | * receiver. | |
753 | * The receiver accepts the message and returns without grabbing the queue | |
754 | * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers | |
755 | * are necessary. The same algorithm is used for sysv semaphores, see | |
756 | * ipc/sem.c fore more details. | |
757 | * | |
758 | * The same algorithm is used for senders. | |
759 | */ | |
760 | ||
761 | /* pipelined_send() - send a message directly to the task waiting in | |
762 | * sys_mq_timedreceive() (without inserting message into a queue). | |
763 | */ | |
764 | static inline void pipelined_send(struct mqueue_inode_info *info, | |
765 | struct msg_msg *message, | |
766 | struct ext_wait_queue *receiver) | |
767 | { | |
768 | receiver->msg = message; | |
769 | list_del(&receiver->list); | |
770 | receiver->state = STATE_PENDING; | |
771 | wake_up_process(receiver->task); | |
d59dd462 | 772 | smp_wmb(); |
1da177e4 LT |
773 | receiver->state = STATE_READY; |
774 | } | |
775 | ||
776 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() | |
777 | * gets its message and put to the queue (we have one free place for sure). */ | |
778 | static inline void pipelined_receive(struct mqueue_inode_info *info) | |
779 | { | |
780 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); | |
781 | ||
782 | if (!sender) { | |
783 | /* for poll */ | |
784 | wake_up_interruptible(&info->wait_q); | |
785 | return; | |
786 | } | |
787 | msg_insert(sender->msg, info); | |
788 | list_del(&sender->list); | |
789 | sender->state = STATE_PENDING; | |
790 | wake_up_process(sender->task); | |
d59dd462 | 791 | smp_wmb(); |
1da177e4 LT |
792 | sender->state = STATE_READY; |
793 | } | |
794 | ||
795 | asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr, | |
796 | size_t msg_len, unsigned int msg_prio, | |
797 | const struct timespec __user *u_abs_timeout) | |
798 | { | |
799 | struct file *filp; | |
800 | struct inode *inode; | |
801 | struct ext_wait_queue wait; | |
802 | struct ext_wait_queue *receiver; | |
803 | struct msg_msg *msg_ptr; | |
804 | struct mqueue_inode_info *info; | |
805 | long timeout; | |
806 | int ret; | |
807 | ||
808 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) | |
809 | return -EINVAL; | |
810 | ||
811 | timeout = prepare_timeout(u_abs_timeout); | |
812 | ||
813 | ret = -EBADF; | |
814 | filp = fget(mqdes); | |
815 | if (unlikely(!filp)) | |
816 | goto out; | |
817 | ||
818 | inode = filp->f_dentry->d_inode; | |
819 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
820 | goto out_fput; | |
821 | info = MQUEUE_I(inode); | |
822 | ||
823 | if (unlikely(!(filp->f_mode & FMODE_WRITE))) | |
824 | goto out_fput; | |
825 | ||
826 | if (unlikely(msg_len > info->attr.mq_msgsize)) { | |
827 | ret = -EMSGSIZE; | |
828 | goto out_fput; | |
829 | } | |
830 | ||
831 | /* First try to allocate memory, before doing anything with | |
832 | * existing queues. */ | |
833 | msg_ptr = load_msg(u_msg_ptr, msg_len); | |
834 | if (IS_ERR(msg_ptr)) { | |
835 | ret = PTR_ERR(msg_ptr); | |
836 | goto out_fput; | |
837 | } | |
838 | msg_ptr->m_ts = msg_len; | |
839 | msg_ptr->m_type = msg_prio; | |
840 | ||
841 | spin_lock(&info->lock); | |
842 | ||
843 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { | |
844 | if (filp->f_flags & O_NONBLOCK) { | |
845 | spin_unlock(&info->lock); | |
846 | ret = -EAGAIN; | |
847 | } else if (unlikely(timeout < 0)) { | |
848 | spin_unlock(&info->lock); | |
849 | ret = timeout; | |
850 | } else { | |
851 | wait.task = current; | |
852 | wait.msg = (void *) msg_ptr; | |
853 | wait.state = STATE_NONE; | |
854 | ret = wq_sleep(info, SEND, timeout, &wait); | |
855 | } | |
856 | if (ret < 0) | |
857 | free_msg(msg_ptr); | |
858 | } else { | |
859 | receiver = wq_get_first_waiter(info, RECV); | |
860 | if (receiver) { | |
861 | pipelined_send(info, msg_ptr, receiver); | |
862 | } else { | |
863 | /* adds message to the queue */ | |
864 | msg_insert(msg_ptr, info); | |
865 | __do_notify(info); | |
866 | } | |
867 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
868 | CURRENT_TIME; | |
869 | spin_unlock(&info->lock); | |
870 | ret = 0; | |
871 | } | |
872 | out_fput: | |
873 | fput(filp); | |
874 | out: | |
875 | return ret; | |
876 | } | |
877 | ||
878 | asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr, | |
879 | size_t msg_len, unsigned int __user *u_msg_prio, | |
880 | const struct timespec __user *u_abs_timeout) | |
881 | { | |
882 | long timeout; | |
883 | ssize_t ret; | |
884 | struct msg_msg *msg_ptr; | |
885 | struct file *filp; | |
886 | struct inode *inode; | |
887 | struct mqueue_inode_info *info; | |
888 | struct ext_wait_queue wait; | |
889 | ||
890 | timeout = prepare_timeout(u_abs_timeout); | |
891 | ||
892 | ret = -EBADF; | |
893 | filp = fget(mqdes); | |
894 | if (unlikely(!filp)) | |
895 | goto out; | |
896 | ||
897 | inode = filp->f_dentry->d_inode; | |
898 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
899 | goto out_fput; | |
900 | info = MQUEUE_I(inode); | |
901 | ||
902 | if (unlikely(!(filp->f_mode & FMODE_READ))) | |
903 | goto out_fput; | |
904 | ||
905 | /* checks if buffer is big enough */ | |
906 | if (unlikely(msg_len < info->attr.mq_msgsize)) { | |
907 | ret = -EMSGSIZE; | |
908 | goto out_fput; | |
909 | } | |
910 | ||
911 | spin_lock(&info->lock); | |
912 | if (info->attr.mq_curmsgs == 0) { | |
913 | if (filp->f_flags & O_NONBLOCK) { | |
914 | spin_unlock(&info->lock); | |
915 | ret = -EAGAIN; | |
916 | msg_ptr = NULL; | |
917 | } else if (unlikely(timeout < 0)) { | |
918 | spin_unlock(&info->lock); | |
919 | ret = timeout; | |
920 | msg_ptr = NULL; | |
921 | } else { | |
922 | wait.task = current; | |
923 | wait.state = STATE_NONE; | |
924 | ret = wq_sleep(info, RECV, timeout, &wait); | |
925 | msg_ptr = wait.msg; | |
926 | } | |
927 | } else { | |
928 | msg_ptr = msg_get(info); | |
929 | ||
930 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
931 | CURRENT_TIME; | |
932 | ||
933 | /* There is now free space in queue. */ | |
934 | pipelined_receive(info); | |
935 | spin_unlock(&info->lock); | |
936 | ret = 0; | |
937 | } | |
938 | if (ret == 0) { | |
939 | ret = msg_ptr->m_ts; | |
940 | ||
941 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || | |
942 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { | |
943 | ret = -EFAULT; | |
944 | } | |
945 | free_msg(msg_ptr); | |
946 | } | |
947 | out_fput: | |
948 | fput(filp); | |
949 | out: | |
950 | return ret; | |
951 | } | |
952 | ||
953 | /* | |
954 | * Notes: the case when user wants us to deregister (with NULL as pointer) | |
955 | * and he isn't currently owner of notification, will be silently discarded. | |
956 | * It isn't explicitly defined in the POSIX. | |
957 | */ | |
958 | asmlinkage long sys_mq_notify(mqd_t mqdes, | |
959 | const struct sigevent __user *u_notification) | |
960 | { | |
961 | int ret; | |
962 | struct file *filp; | |
963 | struct sock *sock; | |
964 | struct inode *inode; | |
965 | struct sigevent notification; | |
966 | struct mqueue_inode_info *info; | |
967 | struct sk_buff *nc; | |
968 | ||
969 | nc = NULL; | |
970 | sock = NULL; | |
971 | if (u_notification != NULL) { | |
972 | if (copy_from_user(¬ification, u_notification, | |
973 | sizeof(struct sigevent))) | |
974 | return -EFAULT; | |
975 | ||
976 | if (unlikely(notification.sigev_notify != SIGEV_NONE && | |
977 | notification.sigev_notify != SIGEV_SIGNAL && | |
978 | notification.sigev_notify != SIGEV_THREAD)) | |
979 | return -EINVAL; | |
980 | if (notification.sigev_notify == SIGEV_SIGNAL && | |
7ed20e1a | 981 | !valid_signal(notification.sigev_signo)) { |
1da177e4 LT |
982 | return -EINVAL; |
983 | } | |
984 | if (notification.sigev_notify == SIGEV_THREAD) { | |
985 | /* create the notify skb */ | |
986 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); | |
987 | ret = -ENOMEM; | |
988 | if (!nc) | |
989 | goto out; | |
990 | ret = -EFAULT; | |
991 | if (copy_from_user(nc->data, | |
992 | notification.sigev_value.sival_ptr, | |
993 | NOTIFY_COOKIE_LEN)) { | |
994 | goto out; | |
995 | } | |
996 | ||
997 | /* TODO: add a header? */ | |
998 | skb_put(nc, NOTIFY_COOKIE_LEN); | |
999 | /* and attach it to the socket */ | |
1000 | retry: | |
1001 | filp = fget(notification.sigev_signo); | |
1002 | ret = -EBADF; | |
1003 | if (!filp) | |
1004 | goto out; | |
1005 | sock = netlink_getsockbyfilp(filp); | |
1006 | fput(filp); | |
1007 | if (IS_ERR(sock)) { | |
1008 | ret = PTR_ERR(sock); | |
1009 | sock = NULL; | |
1010 | goto out; | |
1011 | } | |
1012 | ||
1013 | ret = netlink_attachskb(sock, nc, 0, MAX_SCHEDULE_TIMEOUT); | |
1014 | if (ret == 1) | |
1015 | goto retry; | |
1016 | if (ret) { | |
1017 | sock = NULL; | |
1018 | nc = NULL; | |
1019 | goto out; | |
1020 | } | |
1021 | } | |
1022 | } | |
1023 | ||
1024 | ret = -EBADF; | |
1025 | filp = fget(mqdes); | |
1026 | if (!filp) | |
1027 | goto out; | |
1028 | ||
1029 | inode = filp->f_dentry->d_inode; | |
1030 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
1031 | goto out_fput; | |
1032 | info = MQUEUE_I(inode); | |
1033 | ||
1034 | ret = 0; | |
1035 | spin_lock(&info->lock); | |
1036 | if (u_notification == NULL) { | |
1037 | if (info->notify_owner == current->tgid) { | |
1038 | remove_notification(info); | |
1039 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1040 | } | |
1041 | } else if (info->notify_owner != 0) { | |
1042 | ret = -EBUSY; | |
1043 | } else { | |
1044 | switch (notification.sigev_notify) { | |
1045 | case SIGEV_NONE: | |
1046 | info->notify.sigev_notify = SIGEV_NONE; | |
1047 | break; | |
1048 | case SIGEV_THREAD: | |
1049 | info->notify_sock = sock; | |
1050 | info->notify_cookie = nc; | |
1051 | sock = NULL; | |
1052 | nc = NULL; | |
1053 | info->notify.sigev_notify = SIGEV_THREAD; | |
1054 | break; | |
1055 | case SIGEV_SIGNAL: | |
1056 | info->notify.sigev_signo = notification.sigev_signo; | |
1057 | info->notify.sigev_value = notification.sigev_value; | |
1058 | info->notify.sigev_notify = SIGEV_SIGNAL; | |
1059 | break; | |
1060 | } | |
1061 | info->notify_owner = current->tgid; | |
1062 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1063 | } | |
1064 | spin_unlock(&info->lock); | |
1065 | out_fput: | |
1066 | fput(filp); | |
1067 | out: | |
1068 | if (sock) { | |
1069 | netlink_detachskb(sock, nc); | |
1070 | } else if (nc) { | |
1071 | dev_kfree_skb(nc); | |
1072 | } | |
1073 | return ret; | |
1074 | } | |
1075 | ||
1076 | asmlinkage long sys_mq_getsetattr(mqd_t mqdes, | |
1077 | const struct mq_attr __user *u_mqstat, | |
1078 | struct mq_attr __user *u_omqstat) | |
1079 | { | |
1080 | int ret; | |
1081 | struct mq_attr mqstat, omqstat; | |
1082 | struct file *filp; | |
1083 | struct inode *inode; | |
1084 | struct mqueue_inode_info *info; | |
1085 | ||
1086 | if (u_mqstat != NULL) { | |
1087 | if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) | |
1088 | return -EFAULT; | |
1089 | if (mqstat.mq_flags & (~O_NONBLOCK)) | |
1090 | return -EINVAL; | |
1091 | } | |
1092 | ||
1093 | ret = -EBADF; | |
1094 | filp = fget(mqdes); | |
1095 | if (!filp) | |
1096 | goto out; | |
1097 | ||
1098 | inode = filp->f_dentry->d_inode; | |
1099 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
1100 | goto out_fput; | |
1101 | info = MQUEUE_I(inode); | |
1102 | ||
1103 | spin_lock(&info->lock); | |
1104 | ||
1105 | omqstat = info->attr; | |
1106 | omqstat.mq_flags = filp->f_flags & O_NONBLOCK; | |
1107 | if (u_mqstat) { | |
1108 | if (mqstat.mq_flags & O_NONBLOCK) | |
1109 | filp->f_flags |= O_NONBLOCK; | |
1110 | else | |
1111 | filp->f_flags &= ~O_NONBLOCK; | |
1112 | ||
1113 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1114 | } | |
1115 | ||
1116 | spin_unlock(&info->lock); | |
1117 | ||
1118 | ret = 0; | |
1119 | if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, | |
1120 | sizeof(struct mq_attr))) | |
1121 | ret = -EFAULT; | |
1122 | ||
1123 | out_fput: | |
1124 | fput(filp); | |
1125 | out: | |
1126 | return ret; | |
1127 | } | |
1128 | ||
1129 | static struct inode_operations mqueue_dir_inode_operations = { | |
1130 | .lookup = simple_lookup, | |
1131 | .create = mqueue_create, | |
1132 | .unlink = mqueue_unlink, | |
1133 | }; | |
1134 | ||
1135 | static struct file_operations mqueue_file_operations = { | |
1136 | .flush = mqueue_flush_file, | |
1137 | .poll = mqueue_poll_file, | |
1138 | .read = mqueue_read_file, | |
1139 | }; | |
1140 | ||
1141 | static struct super_operations mqueue_super_ops = { | |
1142 | .alloc_inode = mqueue_alloc_inode, | |
1143 | .destroy_inode = mqueue_destroy_inode, | |
1144 | .statfs = simple_statfs, | |
1145 | .delete_inode = mqueue_delete_inode, | |
1146 | .drop_inode = generic_delete_inode, | |
1147 | }; | |
1148 | ||
1149 | static struct file_system_type mqueue_fs_type = { | |
1150 | .name = "mqueue", | |
1151 | .get_sb = mqueue_get_sb, | |
1152 | .kill_sb = kill_litter_super, | |
1153 | }; | |
1154 | ||
1155 | static int msg_max_limit_min = DFLT_MSGMAX; | |
1156 | static int msg_max_limit_max = HARD_MSGMAX; | |
1157 | ||
1158 | static int msg_maxsize_limit_min = DFLT_MSGSIZEMAX; | |
1159 | static int msg_maxsize_limit_max = INT_MAX; | |
1160 | ||
1161 | static ctl_table mq_sysctls[] = { | |
1162 | { | |
1163 | .ctl_name = CTL_QUEUESMAX, | |
1164 | .procname = "queues_max", | |
1165 | .data = &queues_max, | |
1166 | .maxlen = sizeof(int), | |
1167 | .mode = 0644, | |
1168 | .proc_handler = &proc_dointvec, | |
1169 | }, | |
1170 | { | |
1171 | .ctl_name = CTL_MSGMAX, | |
1172 | .procname = "msg_max", | |
1173 | .data = &msg_max, | |
1174 | .maxlen = sizeof(int), | |
1175 | .mode = 0644, | |
1176 | .proc_handler = &proc_dointvec_minmax, | |
1177 | .extra1 = &msg_max_limit_min, | |
1178 | .extra2 = &msg_max_limit_max, | |
1179 | }, | |
1180 | { | |
1181 | .ctl_name = CTL_MSGSIZEMAX, | |
1182 | .procname = "msgsize_max", | |
1183 | .data = &msgsize_max, | |
1184 | .maxlen = sizeof(int), | |
1185 | .mode = 0644, | |
1186 | .proc_handler = &proc_dointvec_minmax, | |
1187 | .extra1 = &msg_maxsize_limit_min, | |
1188 | .extra2 = &msg_maxsize_limit_max, | |
1189 | }, | |
1190 | { .ctl_name = 0 } | |
1191 | }; | |
1192 | ||
1193 | static ctl_table mq_sysctl_dir[] = { | |
1194 | { | |
1195 | .ctl_name = FS_MQUEUE, | |
1196 | .procname = "mqueue", | |
1197 | .mode = 0555, | |
1198 | .child = mq_sysctls, | |
1199 | }, | |
1200 | { .ctl_name = 0 } | |
1201 | }; | |
1202 | ||
1203 | static ctl_table mq_sysctl_root[] = { | |
1204 | { | |
1205 | .ctl_name = CTL_FS, | |
1206 | .procname = "fs", | |
1207 | .mode = 0555, | |
1208 | .child = mq_sysctl_dir, | |
1209 | }, | |
1210 | { .ctl_name = 0 } | |
1211 | }; | |
1212 | ||
1213 | static int __init init_mqueue_fs(void) | |
1214 | { | |
1215 | int error; | |
1216 | ||
1217 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", | |
1218 | sizeof(struct mqueue_inode_info), 0, | |
1219 | SLAB_HWCACHE_ALIGN, init_once, NULL); | |
1220 | if (mqueue_inode_cachep == NULL) | |
1221 | return -ENOMEM; | |
1222 | ||
1223 | /* ignore failues - they are not fatal */ | |
1224 | mq_sysctl_table = register_sysctl_table(mq_sysctl_root, 0); | |
1225 | ||
1226 | error = register_filesystem(&mqueue_fs_type); | |
1227 | if (error) | |
1228 | goto out_sysctl; | |
1229 | ||
1230 | if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) { | |
1231 | error = PTR_ERR(mqueue_mnt); | |
1232 | goto out_filesystem; | |
1233 | } | |
1234 | ||
1235 | /* internal initialization - not common for vfs */ | |
1236 | queues_count = 0; | |
1237 | spin_lock_init(&mq_lock); | |
1238 | ||
1239 | return 0; | |
1240 | ||
1241 | out_filesystem: | |
1242 | unregister_filesystem(&mqueue_fs_type); | |
1243 | out_sysctl: | |
1244 | if (mq_sysctl_table) | |
1245 | unregister_sysctl_table(mq_sysctl_table); | |
1246 | if (kmem_cache_destroy(mqueue_inode_cachep)) { | |
1247 | printk(KERN_INFO | |
1248 | "mqueue_inode_cache: not all structures were freed\n"); | |
1249 | } | |
1250 | return error; | |
1251 | } | |
1252 | ||
1253 | __initcall(init_mqueue_fs); |