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1 | /* | |
2 | * POSIX message queues filesystem for Linux. | |
3 | * | |
4 | * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl) | |
5 | * Michal Wronski (michal.wronski@gmail.com) | |
6 | * | |
7 | * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com) | |
8 | * Lockless receive & send, fd based notify: | |
9 | * Manfred Spraul (manfred@colorfullife.com) | |
10 | * | |
11 | * Audit: George Wilson (ltcgcw@us.ibm.com) | |
12 | * | |
13 | * This file is released under the GPL. | |
14 | */ | |
15 | ||
16 | #include <linux/capability.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/pagemap.h> | |
19 | #include <linux/file.h> | |
20 | #include <linux/mount.h> | |
21 | #include <linux/namei.h> | |
22 | #include <linux/sysctl.h> | |
23 | #include <linux/poll.h> | |
24 | #include <linux/mqueue.h> | |
25 | #include <linux/msg.h> | |
26 | #include <linux/skbuff.h> | |
27 | #include <linux/netlink.h> | |
28 | #include <linux/syscalls.h> | |
29 | #include <linux/audit.h> | |
30 | #include <linux/signal.h> | |
31 | #include <linux/mutex.h> | |
32 | #include <linux/nsproxy.h> | |
33 | #include <linux/pid.h> | |
34 | ||
35 | #include <net/sock.h> | |
36 | #include "util.h" | |
37 | ||
38 | #define MQUEUE_MAGIC 0x19800202 | |
39 | #define DIRENT_SIZE 20 | |
40 | #define FILENT_SIZE 80 | |
41 | ||
42 | #define SEND 0 | |
43 | #define RECV 1 | |
44 | ||
45 | #define STATE_NONE 0 | |
46 | #define STATE_PENDING 1 | |
47 | #define STATE_READY 2 | |
48 | ||
49 | /* default values */ | |
50 | #define DFLT_QUEUESMAX 256 /* max number of message queues */ | |
51 | #define DFLT_MSGMAX 10 /* max number of messages in each queue */ | |
52 | #define HARD_MSGMAX (131072/sizeof(void*)) | |
53 | #define DFLT_MSGSIZEMAX 8192 /* max message size */ | |
54 | ||
55 | /* | |
56 | * Define the ranges various user-specified maximum values can | |
57 | * be set to. | |
58 | */ | |
59 | #define MIN_MSGMAX 1 /* min value for msg_max */ | |
60 | #define MAX_MSGMAX HARD_MSGMAX /* max value for msg_max */ | |
61 | #define MIN_MSGSIZEMAX 128 /* min value for msgsize_max */ | |
62 | #define MAX_MSGSIZEMAX (8192*128) /* max value for msgsize_max */ | |
63 | ||
64 | struct ext_wait_queue { /* queue of sleeping tasks */ | |
65 | struct task_struct *task; | |
66 | struct list_head list; | |
67 | struct msg_msg *msg; /* ptr of loaded message */ | |
68 | int state; /* one of STATE_* values */ | |
69 | }; | |
70 | ||
71 | struct mqueue_inode_info { | |
72 | spinlock_t lock; | |
73 | struct inode vfs_inode; | |
74 | wait_queue_head_t wait_q; | |
75 | ||
76 | struct msg_msg **messages; | |
77 | struct mq_attr attr; | |
78 | ||
79 | struct sigevent notify; | |
80 | struct pid* notify_owner; | |
81 | struct user_struct *user; /* user who created, for accounting */ | |
82 | struct sock *notify_sock; | |
83 | struct sk_buff *notify_cookie; | |
84 | ||
85 | /* for tasks waiting for free space and messages, respectively */ | |
86 | struct ext_wait_queue e_wait_q[2]; | |
87 | ||
88 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ | |
89 | }; | |
90 | ||
91 | static const struct inode_operations mqueue_dir_inode_operations; | |
92 | static const struct file_operations mqueue_file_operations; | |
93 | static struct super_operations mqueue_super_ops; | |
94 | static void remove_notification(struct mqueue_inode_info *info); | |
95 | ||
96 | static spinlock_t mq_lock; | |
97 | static struct kmem_cache *mqueue_inode_cachep; | |
98 | static struct vfsmount *mqueue_mnt; | |
99 | ||
100 | static unsigned int queues_count; | |
101 | static unsigned int queues_max = DFLT_QUEUESMAX; | |
102 | static unsigned int msg_max = DFLT_MSGMAX; | |
103 | static unsigned int msgsize_max = DFLT_MSGSIZEMAX; | |
104 | ||
105 | static struct ctl_table_header * mq_sysctl_table; | |
106 | ||
107 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) | |
108 | { | |
109 | return container_of(inode, struct mqueue_inode_info, vfs_inode); | |
110 | } | |
111 | ||
112 | static struct inode *mqueue_get_inode(struct super_block *sb, int mode, | |
113 | struct mq_attr *attr) | |
114 | { | |
115 | struct user_struct *u = current_user(); | |
116 | struct inode *inode; | |
117 | ||
118 | inode = new_inode(sb); | |
119 | if (inode) { | |
120 | inode->i_mode = mode; | |
121 | inode->i_uid = current_fsuid(); | |
122 | inode->i_gid = current_fsgid(); | |
123 | inode->i_mtime = inode->i_ctime = inode->i_atime = | |
124 | CURRENT_TIME; | |
125 | ||
126 | if (S_ISREG(mode)) { | |
127 | struct mqueue_inode_info *info; | |
128 | struct task_struct *p = current; | |
129 | unsigned long mq_bytes, mq_msg_tblsz; | |
130 | ||
131 | inode->i_fop = &mqueue_file_operations; | |
132 | inode->i_size = FILENT_SIZE; | |
133 | /* mqueue specific info */ | |
134 | info = MQUEUE_I(inode); | |
135 | spin_lock_init(&info->lock); | |
136 | init_waitqueue_head(&info->wait_q); | |
137 | INIT_LIST_HEAD(&info->e_wait_q[0].list); | |
138 | INIT_LIST_HEAD(&info->e_wait_q[1].list); | |
139 | info->messages = NULL; | |
140 | info->notify_owner = NULL; | |
141 | info->qsize = 0; | |
142 | info->user = NULL; /* set when all is ok */ | |
143 | memset(&info->attr, 0, sizeof(info->attr)); | |
144 | info->attr.mq_maxmsg = msg_max; | |
145 | info->attr.mq_msgsize = msgsize_max; | |
146 | if (attr) { | |
147 | info->attr.mq_maxmsg = attr->mq_maxmsg; | |
148 | info->attr.mq_msgsize = attr->mq_msgsize; | |
149 | } | |
150 | mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *); | |
151 | mq_bytes = (mq_msg_tblsz + | |
152 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
153 | ||
154 | spin_lock(&mq_lock); | |
155 | if (u->mq_bytes + mq_bytes < u->mq_bytes || | |
156 | u->mq_bytes + mq_bytes > | |
157 | p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) { | |
158 | spin_unlock(&mq_lock); | |
159 | goto out_inode; | |
160 | } | |
161 | u->mq_bytes += mq_bytes; | |
162 | spin_unlock(&mq_lock); | |
163 | ||
164 | info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL); | |
165 | if (!info->messages) { | |
166 | spin_lock(&mq_lock); | |
167 | u->mq_bytes -= mq_bytes; | |
168 | spin_unlock(&mq_lock); | |
169 | goto out_inode; | |
170 | } | |
171 | /* all is ok */ | |
172 | info->user = get_uid(u); | |
173 | } else if (S_ISDIR(mode)) { | |
174 | inc_nlink(inode); | |
175 | /* Some things misbehave if size == 0 on a directory */ | |
176 | inode->i_size = 2 * DIRENT_SIZE; | |
177 | inode->i_op = &mqueue_dir_inode_operations; | |
178 | inode->i_fop = &simple_dir_operations; | |
179 | } | |
180 | } | |
181 | return inode; | |
182 | out_inode: | |
183 | make_bad_inode(inode); | |
184 | iput(inode); | |
185 | return NULL; | |
186 | } | |
187 | ||
188 | static int mqueue_fill_super(struct super_block *sb, void *data, int silent) | |
189 | { | |
190 | struct inode *inode; | |
191 | ||
192 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
193 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
194 | sb->s_magic = MQUEUE_MAGIC; | |
195 | sb->s_op = &mqueue_super_ops; | |
196 | ||
197 | inode = mqueue_get_inode(sb, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); | |
198 | if (!inode) | |
199 | return -ENOMEM; | |
200 | ||
201 | sb->s_root = d_alloc_root(inode); | |
202 | if (!sb->s_root) { | |
203 | iput(inode); | |
204 | return -ENOMEM; | |
205 | } | |
206 | ||
207 | return 0; | |
208 | } | |
209 | ||
210 | static int mqueue_get_sb(struct file_system_type *fs_type, | |
211 | int flags, const char *dev_name, | |
212 | void *data, struct vfsmount *mnt) | |
213 | { | |
214 | return get_sb_single(fs_type, flags, data, mqueue_fill_super, mnt); | |
215 | } | |
216 | ||
217 | static void init_once(void *foo) | |
218 | { | |
219 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; | |
220 | ||
221 | inode_init_once(&p->vfs_inode); | |
222 | } | |
223 | ||
224 | static struct inode *mqueue_alloc_inode(struct super_block *sb) | |
225 | { | |
226 | struct mqueue_inode_info *ei; | |
227 | ||
228 | ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL); | |
229 | if (!ei) | |
230 | return NULL; | |
231 | return &ei->vfs_inode; | |
232 | } | |
233 | ||
234 | static void mqueue_destroy_inode(struct inode *inode) | |
235 | { | |
236 | kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); | |
237 | } | |
238 | ||
239 | static void mqueue_delete_inode(struct inode *inode) | |
240 | { | |
241 | struct mqueue_inode_info *info; | |
242 | struct user_struct *user; | |
243 | unsigned long mq_bytes; | |
244 | int i; | |
245 | ||
246 | if (S_ISDIR(inode->i_mode)) { | |
247 | clear_inode(inode); | |
248 | return; | |
249 | } | |
250 | info = MQUEUE_I(inode); | |
251 | spin_lock(&info->lock); | |
252 | for (i = 0; i < info->attr.mq_curmsgs; i++) | |
253 | free_msg(info->messages[i]); | |
254 | kfree(info->messages); | |
255 | spin_unlock(&info->lock); | |
256 | ||
257 | clear_inode(inode); | |
258 | ||
259 | mq_bytes = (info->attr.mq_maxmsg * sizeof(struct msg_msg *) + | |
260 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
261 | user = info->user; | |
262 | if (user) { | |
263 | spin_lock(&mq_lock); | |
264 | user->mq_bytes -= mq_bytes; | |
265 | queues_count--; | |
266 | spin_unlock(&mq_lock); | |
267 | free_uid(user); | |
268 | } | |
269 | } | |
270 | ||
271 | static int mqueue_create(struct inode *dir, struct dentry *dentry, | |
272 | int mode, struct nameidata *nd) | |
273 | { | |
274 | struct inode *inode; | |
275 | struct mq_attr *attr = dentry->d_fsdata; | |
276 | int error; | |
277 | ||
278 | spin_lock(&mq_lock); | |
279 | if (queues_count >= queues_max && !capable(CAP_SYS_RESOURCE)) { | |
280 | error = -ENOSPC; | |
281 | goto out_lock; | |
282 | } | |
283 | queues_count++; | |
284 | spin_unlock(&mq_lock); | |
285 | ||
286 | inode = mqueue_get_inode(dir->i_sb, mode, attr); | |
287 | if (!inode) { | |
288 | error = -ENOMEM; | |
289 | spin_lock(&mq_lock); | |
290 | queues_count--; | |
291 | goto out_lock; | |
292 | } | |
293 | ||
294 | dir->i_size += DIRENT_SIZE; | |
295 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
296 | ||
297 | d_instantiate(dentry, inode); | |
298 | dget(dentry); | |
299 | return 0; | |
300 | out_lock: | |
301 | spin_unlock(&mq_lock); | |
302 | return error; | |
303 | } | |
304 | ||
305 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) | |
306 | { | |
307 | struct inode *inode = dentry->d_inode; | |
308 | ||
309 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
310 | dir->i_size -= DIRENT_SIZE; | |
311 | drop_nlink(inode); | |
312 | dput(dentry); | |
313 | return 0; | |
314 | } | |
315 | ||
316 | /* | |
317 | * This is routine for system read from queue file. | |
318 | * To avoid mess with doing here some sort of mq_receive we allow | |
319 | * to read only queue size & notification info (the only values | |
320 | * that are interesting from user point of view and aren't accessible | |
321 | * through std routines) | |
322 | */ | |
323 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, | |
324 | size_t count, loff_t *off) | |
325 | { | |
326 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); | |
327 | char buffer[FILENT_SIZE]; | |
328 | ssize_t ret; | |
329 | ||
330 | spin_lock(&info->lock); | |
331 | snprintf(buffer, sizeof(buffer), | |
332 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", | |
333 | info->qsize, | |
334 | info->notify_owner ? info->notify.sigev_notify : 0, | |
335 | (info->notify_owner && | |
336 | info->notify.sigev_notify == SIGEV_SIGNAL) ? | |
337 | info->notify.sigev_signo : 0, | |
338 | pid_vnr(info->notify_owner)); | |
339 | spin_unlock(&info->lock); | |
340 | buffer[sizeof(buffer)-1] = '\0'; | |
341 | ||
342 | ret = simple_read_from_buffer(u_data, count, off, buffer, | |
343 | strlen(buffer)); | |
344 | if (ret <= 0) | |
345 | return ret; | |
346 | ||
347 | filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME; | |
348 | return ret; | |
349 | } | |
350 | ||
351 | static int mqueue_flush_file(struct file *filp, fl_owner_t id) | |
352 | { | |
353 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); | |
354 | ||
355 | spin_lock(&info->lock); | |
356 | if (task_tgid(current) == info->notify_owner) | |
357 | remove_notification(info); | |
358 | ||
359 | spin_unlock(&info->lock); | |
360 | return 0; | |
361 | } | |
362 | ||
363 | static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) | |
364 | { | |
365 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); | |
366 | int retval = 0; | |
367 | ||
368 | poll_wait(filp, &info->wait_q, poll_tab); | |
369 | ||
370 | spin_lock(&info->lock); | |
371 | if (info->attr.mq_curmsgs) | |
372 | retval = POLLIN | POLLRDNORM; | |
373 | ||
374 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) | |
375 | retval |= POLLOUT | POLLWRNORM; | |
376 | spin_unlock(&info->lock); | |
377 | ||
378 | return retval; | |
379 | } | |
380 | ||
381 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ | |
382 | static void wq_add(struct mqueue_inode_info *info, int sr, | |
383 | struct ext_wait_queue *ewp) | |
384 | { | |
385 | struct ext_wait_queue *walk; | |
386 | ||
387 | ewp->task = current; | |
388 | ||
389 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { | |
390 | if (walk->task->static_prio <= current->static_prio) { | |
391 | list_add_tail(&ewp->list, &walk->list); | |
392 | return; | |
393 | } | |
394 | } | |
395 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); | |
396 | } | |
397 | ||
398 | /* | |
399 | * Puts current task to sleep. Caller must hold queue lock. After return | |
400 | * lock isn't held. | |
401 | * sr: SEND or RECV | |
402 | */ | |
403 | static int wq_sleep(struct mqueue_inode_info *info, int sr, | |
404 | long timeout, struct ext_wait_queue *ewp) | |
405 | { | |
406 | int retval; | |
407 | signed long time; | |
408 | ||
409 | wq_add(info, sr, ewp); | |
410 | ||
411 | for (;;) { | |
412 | set_current_state(TASK_INTERRUPTIBLE); | |
413 | ||
414 | spin_unlock(&info->lock); | |
415 | time = schedule_timeout(timeout); | |
416 | ||
417 | while (ewp->state == STATE_PENDING) | |
418 | cpu_relax(); | |
419 | ||
420 | if (ewp->state == STATE_READY) { | |
421 | retval = 0; | |
422 | goto out; | |
423 | } | |
424 | spin_lock(&info->lock); | |
425 | if (ewp->state == STATE_READY) { | |
426 | retval = 0; | |
427 | goto out_unlock; | |
428 | } | |
429 | if (signal_pending(current)) { | |
430 | retval = -ERESTARTSYS; | |
431 | break; | |
432 | } | |
433 | if (time == 0) { | |
434 | retval = -ETIMEDOUT; | |
435 | break; | |
436 | } | |
437 | } | |
438 | list_del(&ewp->list); | |
439 | out_unlock: | |
440 | spin_unlock(&info->lock); | |
441 | out: | |
442 | return retval; | |
443 | } | |
444 | ||
445 | /* | |
446 | * Returns waiting task that should be serviced first or NULL if none exists | |
447 | */ | |
448 | static struct ext_wait_queue *wq_get_first_waiter( | |
449 | struct mqueue_inode_info *info, int sr) | |
450 | { | |
451 | struct list_head *ptr; | |
452 | ||
453 | ptr = info->e_wait_q[sr].list.prev; | |
454 | if (ptr == &info->e_wait_q[sr].list) | |
455 | return NULL; | |
456 | return list_entry(ptr, struct ext_wait_queue, list); | |
457 | } | |
458 | ||
459 | /* Auxiliary functions to manipulate messages' list */ | |
460 | static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info) | |
461 | { | |
462 | int k; | |
463 | ||
464 | k = info->attr.mq_curmsgs - 1; | |
465 | while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) { | |
466 | info->messages[k + 1] = info->messages[k]; | |
467 | k--; | |
468 | } | |
469 | info->attr.mq_curmsgs++; | |
470 | info->qsize += ptr->m_ts; | |
471 | info->messages[k + 1] = ptr; | |
472 | } | |
473 | ||
474 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) | |
475 | { | |
476 | info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts; | |
477 | return info->messages[info->attr.mq_curmsgs]; | |
478 | } | |
479 | ||
480 | static inline void set_cookie(struct sk_buff *skb, char code) | |
481 | { | |
482 | ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; | |
483 | } | |
484 | ||
485 | /* | |
486 | * The next function is only to split too long sys_mq_timedsend | |
487 | */ | |
488 | static void __do_notify(struct mqueue_inode_info *info) | |
489 | { | |
490 | /* notification | |
491 | * invoked when there is registered process and there isn't process | |
492 | * waiting synchronously for message AND state of queue changed from | |
493 | * empty to not empty. Here we are sure that no one is waiting | |
494 | * synchronously. */ | |
495 | if (info->notify_owner && | |
496 | info->attr.mq_curmsgs == 1) { | |
497 | struct siginfo sig_i; | |
498 | switch (info->notify.sigev_notify) { | |
499 | case SIGEV_NONE: | |
500 | break; | |
501 | case SIGEV_SIGNAL: | |
502 | /* sends signal */ | |
503 | ||
504 | sig_i.si_signo = info->notify.sigev_signo; | |
505 | sig_i.si_errno = 0; | |
506 | sig_i.si_code = SI_MESGQ; | |
507 | sig_i.si_value = info->notify.sigev_value; | |
508 | sig_i.si_pid = task_tgid_nr_ns(current, | |
509 | ns_of_pid(info->notify_owner)); | |
510 | sig_i.si_uid = current_uid(); | |
511 | ||
512 | kill_pid_info(info->notify.sigev_signo, | |
513 | &sig_i, info->notify_owner); | |
514 | break; | |
515 | case SIGEV_THREAD: | |
516 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); | |
517 | netlink_sendskb(info->notify_sock, info->notify_cookie); | |
518 | break; | |
519 | } | |
520 | /* after notification unregisters process */ | |
521 | put_pid(info->notify_owner); | |
522 | info->notify_owner = NULL; | |
523 | } | |
524 | wake_up(&info->wait_q); | |
525 | } | |
526 | ||
527 | static long prepare_timeout(struct timespec *p) | |
528 | { | |
529 | struct timespec nowts; | |
530 | long timeout; | |
531 | ||
532 | if (p) { | |
533 | if (unlikely(p->tv_nsec < 0 || p->tv_sec < 0 | |
534 | || p->tv_nsec >= NSEC_PER_SEC)) | |
535 | return -EINVAL; | |
536 | nowts = CURRENT_TIME; | |
537 | /* first subtract as jiffies can't be too big */ | |
538 | p->tv_sec -= nowts.tv_sec; | |
539 | if (p->tv_nsec < nowts.tv_nsec) { | |
540 | p->tv_nsec += NSEC_PER_SEC; | |
541 | p->tv_sec--; | |
542 | } | |
543 | p->tv_nsec -= nowts.tv_nsec; | |
544 | if (p->tv_sec < 0) | |
545 | return 0; | |
546 | ||
547 | timeout = timespec_to_jiffies(p) + 1; | |
548 | } else | |
549 | return MAX_SCHEDULE_TIMEOUT; | |
550 | ||
551 | return timeout; | |
552 | } | |
553 | ||
554 | static void remove_notification(struct mqueue_inode_info *info) | |
555 | { | |
556 | if (info->notify_owner != NULL && | |
557 | info->notify.sigev_notify == SIGEV_THREAD) { | |
558 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); | |
559 | netlink_sendskb(info->notify_sock, info->notify_cookie); | |
560 | } | |
561 | put_pid(info->notify_owner); | |
562 | info->notify_owner = NULL; | |
563 | } | |
564 | ||
565 | static int mq_attr_ok(struct mq_attr *attr) | |
566 | { | |
567 | if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) | |
568 | return 0; | |
569 | if (capable(CAP_SYS_RESOURCE)) { | |
570 | if (attr->mq_maxmsg > HARD_MSGMAX) | |
571 | return 0; | |
572 | } else { | |
573 | if (attr->mq_maxmsg > msg_max || | |
574 | attr->mq_msgsize > msgsize_max) | |
575 | return 0; | |
576 | } | |
577 | /* check for overflow */ | |
578 | if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) | |
579 | return 0; | |
580 | if ((unsigned long)(attr->mq_maxmsg * attr->mq_msgsize) + | |
581 | (attr->mq_maxmsg * sizeof (struct msg_msg *)) < | |
582 | (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize)) | |
583 | return 0; | |
584 | return 1; | |
585 | } | |
586 | ||
587 | /* | |
588 | * Invoked when creating a new queue via sys_mq_open | |
589 | */ | |
590 | static struct file *do_create(struct dentry *dir, struct dentry *dentry, | |
591 | int oflag, mode_t mode, struct mq_attr *attr) | |
592 | { | |
593 | const struct cred *cred = current_cred(); | |
594 | struct file *result; | |
595 | int ret; | |
596 | ||
597 | if (attr) { | |
598 | ret = -EINVAL; | |
599 | if (!mq_attr_ok(attr)) | |
600 | goto out; | |
601 | /* store for use during create */ | |
602 | dentry->d_fsdata = attr; | |
603 | } | |
604 | ||
605 | mode &= ~current->fs->umask; | |
606 | ret = mnt_want_write(mqueue_mnt); | |
607 | if (ret) | |
608 | goto out; | |
609 | ret = vfs_create(dir->d_inode, dentry, mode, NULL); | |
610 | dentry->d_fsdata = NULL; | |
611 | if (ret) | |
612 | goto out_drop_write; | |
613 | ||
614 | result = dentry_open(dentry, mqueue_mnt, oflag, cred); | |
615 | /* | |
616 | * dentry_open() took a persistent mnt_want_write(), | |
617 | * so we can now drop this one. | |
618 | */ | |
619 | mnt_drop_write(mqueue_mnt); | |
620 | return result; | |
621 | ||
622 | out_drop_write: | |
623 | mnt_drop_write(mqueue_mnt); | |
624 | out: | |
625 | dput(dentry); | |
626 | mntput(mqueue_mnt); | |
627 | return ERR_PTR(ret); | |
628 | } | |
629 | ||
630 | /* Opens existing queue */ | |
631 | static struct file *do_open(struct dentry *dentry, int oflag) | |
632 | { | |
633 | const struct cred *cred = current_cred(); | |
634 | ||
635 | static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, | |
636 | MAY_READ | MAY_WRITE }; | |
637 | ||
638 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { | |
639 | dput(dentry); | |
640 | mntput(mqueue_mnt); | |
641 | return ERR_PTR(-EINVAL); | |
642 | } | |
643 | ||
644 | if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) { | |
645 | dput(dentry); | |
646 | mntput(mqueue_mnt); | |
647 | return ERR_PTR(-EACCES); | |
648 | } | |
649 | ||
650 | return dentry_open(dentry, mqueue_mnt, oflag, cred); | |
651 | } | |
652 | ||
653 | SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode, | |
654 | struct mq_attr __user *, u_attr) | |
655 | { | |
656 | struct dentry *dentry; | |
657 | struct file *filp; | |
658 | char *name; | |
659 | struct mq_attr attr; | |
660 | int fd, error; | |
661 | ||
662 | if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) | |
663 | return -EFAULT; | |
664 | ||
665 | audit_mq_open(oflag, mode, u_attr ? &attr : NULL); | |
666 | ||
667 | if (IS_ERR(name = getname(u_name))) | |
668 | return PTR_ERR(name); | |
669 | ||
670 | fd = get_unused_fd_flags(O_CLOEXEC); | |
671 | if (fd < 0) | |
672 | goto out_putname; | |
673 | ||
674 | mutex_lock(&mqueue_mnt->mnt_root->d_inode->i_mutex); | |
675 | dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name)); | |
676 | if (IS_ERR(dentry)) { | |
677 | error = PTR_ERR(dentry); | |
678 | goto out_err; | |
679 | } | |
680 | mntget(mqueue_mnt); | |
681 | ||
682 | if (oflag & O_CREAT) { | |
683 | if (dentry->d_inode) { /* entry already exists */ | |
684 | audit_inode(name, dentry); | |
685 | error = -EEXIST; | |
686 | if (oflag & O_EXCL) | |
687 | goto out; | |
688 | filp = do_open(dentry, oflag); | |
689 | } else { | |
690 | filp = do_create(mqueue_mnt->mnt_root, dentry, | |
691 | oflag, mode, | |
692 | u_attr ? &attr : NULL); | |
693 | } | |
694 | } else { | |
695 | error = -ENOENT; | |
696 | if (!dentry->d_inode) | |
697 | goto out; | |
698 | audit_inode(name, dentry); | |
699 | filp = do_open(dentry, oflag); | |
700 | } | |
701 | ||
702 | if (IS_ERR(filp)) { | |
703 | error = PTR_ERR(filp); | |
704 | goto out_putfd; | |
705 | } | |
706 | ||
707 | fd_install(fd, filp); | |
708 | goto out_upsem; | |
709 | ||
710 | out: | |
711 | dput(dentry); | |
712 | mntput(mqueue_mnt); | |
713 | out_putfd: | |
714 | put_unused_fd(fd); | |
715 | out_err: | |
716 | fd = error; | |
717 | out_upsem: | |
718 | mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex); | |
719 | out_putname: | |
720 | putname(name); | |
721 | return fd; | |
722 | } | |
723 | ||
724 | SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) | |
725 | { | |
726 | int err; | |
727 | char *name; | |
728 | struct dentry *dentry; | |
729 | struct inode *inode = NULL; | |
730 | ||
731 | name = getname(u_name); | |
732 | if (IS_ERR(name)) | |
733 | return PTR_ERR(name); | |
734 | ||
735 | mutex_lock_nested(&mqueue_mnt->mnt_root->d_inode->i_mutex, | |
736 | I_MUTEX_PARENT); | |
737 | dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name)); | |
738 | if (IS_ERR(dentry)) { | |
739 | err = PTR_ERR(dentry); | |
740 | goto out_unlock; | |
741 | } | |
742 | ||
743 | if (!dentry->d_inode) { | |
744 | err = -ENOENT; | |
745 | goto out_err; | |
746 | } | |
747 | ||
748 | inode = dentry->d_inode; | |
749 | if (inode) | |
750 | atomic_inc(&inode->i_count); | |
751 | err = mnt_want_write(mqueue_mnt); | |
752 | if (err) | |
753 | goto out_err; | |
754 | err = vfs_unlink(dentry->d_parent->d_inode, dentry); | |
755 | mnt_drop_write(mqueue_mnt); | |
756 | out_err: | |
757 | dput(dentry); | |
758 | ||
759 | out_unlock: | |
760 | mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex); | |
761 | putname(name); | |
762 | if (inode) | |
763 | iput(inode); | |
764 | ||
765 | return err; | |
766 | } | |
767 | ||
768 | /* Pipelined send and receive functions. | |
769 | * | |
770 | * If a receiver finds no waiting message, then it registers itself in the | |
771 | * list of waiting receivers. A sender checks that list before adding the new | |
772 | * message into the message array. If there is a waiting receiver, then it | |
773 | * bypasses the message array and directly hands the message over to the | |
774 | * receiver. | |
775 | * The receiver accepts the message and returns without grabbing the queue | |
776 | * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers | |
777 | * are necessary. The same algorithm is used for sysv semaphores, see | |
778 | * ipc/sem.c for more details. | |
779 | * | |
780 | * The same algorithm is used for senders. | |
781 | */ | |
782 | ||
783 | /* pipelined_send() - send a message directly to the task waiting in | |
784 | * sys_mq_timedreceive() (without inserting message into a queue). | |
785 | */ | |
786 | static inline void pipelined_send(struct mqueue_inode_info *info, | |
787 | struct msg_msg *message, | |
788 | struct ext_wait_queue *receiver) | |
789 | { | |
790 | receiver->msg = message; | |
791 | list_del(&receiver->list); | |
792 | receiver->state = STATE_PENDING; | |
793 | wake_up_process(receiver->task); | |
794 | smp_wmb(); | |
795 | receiver->state = STATE_READY; | |
796 | } | |
797 | ||
798 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() | |
799 | * gets its message and put to the queue (we have one free place for sure). */ | |
800 | static inline void pipelined_receive(struct mqueue_inode_info *info) | |
801 | { | |
802 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); | |
803 | ||
804 | if (!sender) { | |
805 | /* for poll */ | |
806 | wake_up_interruptible(&info->wait_q); | |
807 | return; | |
808 | } | |
809 | msg_insert(sender->msg, info); | |
810 | list_del(&sender->list); | |
811 | sender->state = STATE_PENDING; | |
812 | wake_up_process(sender->task); | |
813 | smp_wmb(); | |
814 | sender->state = STATE_READY; | |
815 | } | |
816 | ||
817 | SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr, | |
818 | size_t, msg_len, unsigned int, msg_prio, | |
819 | const struct timespec __user *, u_abs_timeout) | |
820 | { | |
821 | struct file *filp; | |
822 | struct inode *inode; | |
823 | struct ext_wait_queue wait; | |
824 | struct ext_wait_queue *receiver; | |
825 | struct msg_msg *msg_ptr; | |
826 | struct mqueue_inode_info *info; | |
827 | struct timespec ts, *p = NULL; | |
828 | long timeout; | |
829 | int ret; | |
830 | ||
831 | if (u_abs_timeout) { | |
832 | if (copy_from_user(&ts, u_abs_timeout, | |
833 | sizeof(struct timespec))) | |
834 | return -EFAULT; | |
835 | p = &ts; | |
836 | } | |
837 | ||
838 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) | |
839 | return -EINVAL; | |
840 | ||
841 | audit_mq_sendrecv(mqdes, msg_len, msg_prio, p); | |
842 | timeout = prepare_timeout(p); | |
843 | ||
844 | ret = -EBADF; | |
845 | filp = fget(mqdes); | |
846 | if (unlikely(!filp)) | |
847 | goto out; | |
848 | ||
849 | inode = filp->f_path.dentry->d_inode; | |
850 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
851 | goto out_fput; | |
852 | info = MQUEUE_I(inode); | |
853 | audit_inode(NULL, filp->f_path.dentry); | |
854 | ||
855 | if (unlikely(!(filp->f_mode & FMODE_WRITE))) | |
856 | goto out_fput; | |
857 | ||
858 | if (unlikely(msg_len > info->attr.mq_msgsize)) { | |
859 | ret = -EMSGSIZE; | |
860 | goto out_fput; | |
861 | } | |
862 | ||
863 | /* First try to allocate memory, before doing anything with | |
864 | * existing queues. */ | |
865 | msg_ptr = load_msg(u_msg_ptr, msg_len); | |
866 | if (IS_ERR(msg_ptr)) { | |
867 | ret = PTR_ERR(msg_ptr); | |
868 | goto out_fput; | |
869 | } | |
870 | msg_ptr->m_ts = msg_len; | |
871 | msg_ptr->m_type = msg_prio; | |
872 | ||
873 | spin_lock(&info->lock); | |
874 | ||
875 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { | |
876 | if (filp->f_flags & O_NONBLOCK) { | |
877 | spin_unlock(&info->lock); | |
878 | ret = -EAGAIN; | |
879 | } else if (unlikely(timeout < 0)) { | |
880 | spin_unlock(&info->lock); | |
881 | ret = timeout; | |
882 | } else { | |
883 | wait.task = current; | |
884 | wait.msg = (void *) msg_ptr; | |
885 | wait.state = STATE_NONE; | |
886 | ret = wq_sleep(info, SEND, timeout, &wait); | |
887 | } | |
888 | if (ret < 0) | |
889 | free_msg(msg_ptr); | |
890 | } else { | |
891 | receiver = wq_get_first_waiter(info, RECV); | |
892 | if (receiver) { | |
893 | pipelined_send(info, msg_ptr, receiver); | |
894 | } else { | |
895 | /* adds message to the queue */ | |
896 | msg_insert(msg_ptr, info); | |
897 | __do_notify(info); | |
898 | } | |
899 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
900 | CURRENT_TIME; | |
901 | spin_unlock(&info->lock); | |
902 | ret = 0; | |
903 | } | |
904 | out_fput: | |
905 | fput(filp); | |
906 | out: | |
907 | return ret; | |
908 | } | |
909 | ||
910 | SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr, | |
911 | size_t, msg_len, unsigned int __user *, u_msg_prio, | |
912 | const struct timespec __user *, u_abs_timeout) | |
913 | { | |
914 | long timeout; | |
915 | ssize_t ret; | |
916 | struct msg_msg *msg_ptr; | |
917 | struct file *filp; | |
918 | struct inode *inode; | |
919 | struct mqueue_inode_info *info; | |
920 | struct ext_wait_queue wait; | |
921 | struct timespec ts, *p = NULL; | |
922 | ||
923 | if (u_abs_timeout) { | |
924 | if (copy_from_user(&ts, u_abs_timeout, | |
925 | sizeof(struct timespec))) | |
926 | return -EFAULT; | |
927 | p = &ts; | |
928 | } | |
929 | ||
930 | audit_mq_sendrecv(mqdes, msg_len, 0, p); | |
931 | timeout = prepare_timeout(p); | |
932 | ||
933 | ret = -EBADF; | |
934 | filp = fget(mqdes); | |
935 | if (unlikely(!filp)) | |
936 | goto out; | |
937 | ||
938 | inode = filp->f_path.dentry->d_inode; | |
939 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
940 | goto out_fput; | |
941 | info = MQUEUE_I(inode); | |
942 | audit_inode(NULL, filp->f_path.dentry); | |
943 | ||
944 | if (unlikely(!(filp->f_mode & FMODE_READ))) | |
945 | goto out_fput; | |
946 | ||
947 | /* checks if buffer is big enough */ | |
948 | if (unlikely(msg_len < info->attr.mq_msgsize)) { | |
949 | ret = -EMSGSIZE; | |
950 | goto out_fput; | |
951 | } | |
952 | ||
953 | spin_lock(&info->lock); | |
954 | if (info->attr.mq_curmsgs == 0) { | |
955 | if (filp->f_flags & O_NONBLOCK) { | |
956 | spin_unlock(&info->lock); | |
957 | ret = -EAGAIN; | |
958 | msg_ptr = NULL; | |
959 | } else if (unlikely(timeout < 0)) { | |
960 | spin_unlock(&info->lock); | |
961 | ret = timeout; | |
962 | msg_ptr = NULL; | |
963 | } else { | |
964 | wait.task = current; | |
965 | wait.state = STATE_NONE; | |
966 | ret = wq_sleep(info, RECV, timeout, &wait); | |
967 | msg_ptr = wait.msg; | |
968 | } | |
969 | } else { | |
970 | msg_ptr = msg_get(info); | |
971 | ||
972 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
973 | CURRENT_TIME; | |
974 | ||
975 | /* There is now free space in queue. */ | |
976 | pipelined_receive(info); | |
977 | spin_unlock(&info->lock); | |
978 | ret = 0; | |
979 | } | |
980 | if (ret == 0) { | |
981 | ret = msg_ptr->m_ts; | |
982 | ||
983 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || | |
984 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { | |
985 | ret = -EFAULT; | |
986 | } | |
987 | free_msg(msg_ptr); | |
988 | } | |
989 | out_fput: | |
990 | fput(filp); | |
991 | out: | |
992 | return ret; | |
993 | } | |
994 | ||
995 | /* | |
996 | * Notes: the case when user wants us to deregister (with NULL as pointer) | |
997 | * and he isn't currently owner of notification, will be silently discarded. | |
998 | * It isn't explicitly defined in the POSIX. | |
999 | */ | |
1000 | SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, | |
1001 | const struct sigevent __user *, u_notification) | |
1002 | { | |
1003 | int ret; | |
1004 | struct file *filp; | |
1005 | struct sock *sock; | |
1006 | struct inode *inode; | |
1007 | struct sigevent notification; | |
1008 | struct mqueue_inode_info *info; | |
1009 | struct sk_buff *nc; | |
1010 | ||
1011 | if (u_notification) { | |
1012 | if (copy_from_user(¬ification, u_notification, | |
1013 | sizeof(struct sigevent))) | |
1014 | return -EFAULT; | |
1015 | } | |
1016 | ||
1017 | audit_mq_notify(mqdes, u_notification ? ¬ification : NULL); | |
1018 | ||
1019 | nc = NULL; | |
1020 | sock = NULL; | |
1021 | if (u_notification != NULL) { | |
1022 | if (unlikely(notification.sigev_notify != SIGEV_NONE && | |
1023 | notification.sigev_notify != SIGEV_SIGNAL && | |
1024 | notification.sigev_notify != SIGEV_THREAD)) | |
1025 | return -EINVAL; | |
1026 | if (notification.sigev_notify == SIGEV_SIGNAL && | |
1027 | !valid_signal(notification.sigev_signo)) { | |
1028 | return -EINVAL; | |
1029 | } | |
1030 | if (notification.sigev_notify == SIGEV_THREAD) { | |
1031 | long timeo; | |
1032 | ||
1033 | /* create the notify skb */ | |
1034 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); | |
1035 | ret = -ENOMEM; | |
1036 | if (!nc) | |
1037 | goto out; | |
1038 | ret = -EFAULT; | |
1039 | if (copy_from_user(nc->data, | |
1040 | notification.sigev_value.sival_ptr, | |
1041 | NOTIFY_COOKIE_LEN)) { | |
1042 | goto out; | |
1043 | } | |
1044 | ||
1045 | /* TODO: add a header? */ | |
1046 | skb_put(nc, NOTIFY_COOKIE_LEN); | |
1047 | /* and attach it to the socket */ | |
1048 | retry: | |
1049 | filp = fget(notification.sigev_signo); | |
1050 | ret = -EBADF; | |
1051 | if (!filp) | |
1052 | goto out; | |
1053 | sock = netlink_getsockbyfilp(filp); | |
1054 | fput(filp); | |
1055 | if (IS_ERR(sock)) { | |
1056 | ret = PTR_ERR(sock); | |
1057 | sock = NULL; | |
1058 | goto out; | |
1059 | } | |
1060 | ||
1061 | timeo = MAX_SCHEDULE_TIMEOUT; | |
1062 | ret = netlink_attachskb(sock, nc, &timeo, NULL); | |
1063 | if (ret == 1) | |
1064 | goto retry; | |
1065 | if (ret) { | |
1066 | sock = NULL; | |
1067 | nc = NULL; | |
1068 | goto out; | |
1069 | } | |
1070 | } | |
1071 | } | |
1072 | ||
1073 | ret = -EBADF; | |
1074 | filp = fget(mqdes); | |
1075 | if (!filp) | |
1076 | goto out; | |
1077 | ||
1078 | inode = filp->f_path.dentry->d_inode; | |
1079 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
1080 | goto out_fput; | |
1081 | info = MQUEUE_I(inode); | |
1082 | ||
1083 | ret = 0; | |
1084 | spin_lock(&info->lock); | |
1085 | if (u_notification == NULL) { | |
1086 | if (info->notify_owner == task_tgid(current)) { | |
1087 | remove_notification(info); | |
1088 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1089 | } | |
1090 | } else if (info->notify_owner != NULL) { | |
1091 | ret = -EBUSY; | |
1092 | } else { | |
1093 | switch (notification.sigev_notify) { | |
1094 | case SIGEV_NONE: | |
1095 | info->notify.sigev_notify = SIGEV_NONE; | |
1096 | break; | |
1097 | case SIGEV_THREAD: | |
1098 | info->notify_sock = sock; | |
1099 | info->notify_cookie = nc; | |
1100 | sock = NULL; | |
1101 | nc = NULL; | |
1102 | info->notify.sigev_notify = SIGEV_THREAD; | |
1103 | break; | |
1104 | case SIGEV_SIGNAL: | |
1105 | info->notify.sigev_signo = notification.sigev_signo; | |
1106 | info->notify.sigev_value = notification.sigev_value; | |
1107 | info->notify.sigev_notify = SIGEV_SIGNAL; | |
1108 | break; | |
1109 | } | |
1110 | ||
1111 | info->notify_owner = get_pid(task_tgid(current)); | |
1112 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1113 | } | |
1114 | spin_unlock(&info->lock); | |
1115 | out_fput: | |
1116 | fput(filp); | |
1117 | out: | |
1118 | if (sock) { | |
1119 | netlink_detachskb(sock, nc); | |
1120 | } else if (nc) { | |
1121 | dev_kfree_skb(nc); | |
1122 | } | |
1123 | return ret; | |
1124 | } | |
1125 | ||
1126 | SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, | |
1127 | const struct mq_attr __user *, u_mqstat, | |
1128 | struct mq_attr __user *, u_omqstat) | |
1129 | { | |
1130 | int ret; | |
1131 | struct mq_attr mqstat, omqstat; | |
1132 | struct file *filp; | |
1133 | struct inode *inode; | |
1134 | struct mqueue_inode_info *info; | |
1135 | ||
1136 | if (u_mqstat != NULL) { | |
1137 | if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) | |
1138 | return -EFAULT; | |
1139 | if (mqstat.mq_flags & (~O_NONBLOCK)) | |
1140 | return -EINVAL; | |
1141 | } | |
1142 | ||
1143 | ret = -EBADF; | |
1144 | filp = fget(mqdes); | |
1145 | if (!filp) | |
1146 | goto out; | |
1147 | ||
1148 | inode = filp->f_path.dentry->d_inode; | |
1149 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
1150 | goto out_fput; | |
1151 | info = MQUEUE_I(inode); | |
1152 | ||
1153 | spin_lock(&info->lock); | |
1154 | ||
1155 | omqstat = info->attr; | |
1156 | omqstat.mq_flags = filp->f_flags & O_NONBLOCK; | |
1157 | if (u_mqstat) { | |
1158 | audit_mq_getsetattr(mqdes, &mqstat); | |
1159 | spin_lock(&filp->f_lock); | |
1160 | if (mqstat.mq_flags & O_NONBLOCK) | |
1161 | filp->f_flags |= O_NONBLOCK; | |
1162 | else | |
1163 | filp->f_flags &= ~O_NONBLOCK; | |
1164 | spin_unlock(&filp->f_lock); | |
1165 | ||
1166 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1167 | } | |
1168 | ||
1169 | spin_unlock(&info->lock); | |
1170 | ||
1171 | ret = 0; | |
1172 | if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, | |
1173 | sizeof(struct mq_attr))) | |
1174 | ret = -EFAULT; | |
1175 | ||
1176 | out_fput: | |
1177 | fput(filp); | |
1178 | out: | |
1179 | return ret; | |
1180 | } | |
1181 | ||
1182 | static const struct inode_operations mqueue_dir_inode_operations = { | |
1183 | .lookup = simple_lookup, | |
1184 | .create = mqueue_create, | |
1185 | .unlink = mqueue_unlink, | |
1186 | }; | |
1187 | ||
1188 | static const struct file_operations mqueue_file_operations = { | |
1189 | .flush = mqueue_flush_file, | |
1190 | .poll = mqueue_poll_file, | |
1191 | .read = mqueue_read_file, | |
1192 | }; | |
1193 | ||
1194 | static struct super_operations mqueue_super_ops = { | |
1195 | .alloc_inode = mqueue_alloc_inode, | |
1196 | .destroy_inode = mqueue_destroy_inode, | |
1197 | .statfs = simple_statfs, | |
1198 | .delete_inode = mqueue_delete_inode, | |
1199 | .drop_inode = generic_delete_inode, | |
1200 | }; | |
1201 | ||
1202 | static struct file_system_type mqueue_fs_type = { | |
1203 | .name = "mqueue", | |
1204 | .get_sb = mqueue_get_sb, | |
1205 | .kill_sb = kill_litter_super, | |
1206 | }; | |
1207 | ||
1208 | static int msg_max_limit_min = MIN_MSGMAX; | |
1209 | static int msg_max_limit_max = MAX_MSGMAX; | |
1210 | ||
1211 | static int msg_maxsize_limit_min = MIN_MSGSIZEMAX; | |
1212 | static int msg_maxsize_limit_max = MAX_MSGSIZEMAX; | |
1213 | ||
1214 | static ctl_table mq_sysctls[] = { | |
1215 | { | |
1216 | .procname = "queues_max", | |
1217 | .data = &queues_max, | |
1218 | .maxlen = sizeof(int), | |
1219 | .mode = 0644, | |
1220 | .proc_handler = &proc_dointvec, | |
1221 | }, | |
1222 | { | |
1223 | .procname = "msg_max", | |
1224 | .data = &msg_max, | |
1225 | .maxlen = sizeof(int), | |
1226 | .mode = 0644, | |
1227 | .proc_handler = &proc_dointvec_minmax, | |
1228 | .extra1 = &msg_max_limit_min, | |
1229 | .extra2 = &msg_max_limit_max, | |
1230 | }, | |
1231 | { | |
1232 | .procname = "msgsize_max", | |
1233 | .data = &msgsize_max, | |
1234 | .maxlen = sizeof(int), | |
1235 | .mode = 0644, | |
1236 | .proc_handler = &proc_dointvec_minmax, | |
1237 | .extra1 = &msg_maxsize_limit_min, | |
1238 | .extra2 = &msg_maxsize_limit_max, | |
1239 | }, | |
1240 | { .ctl_name = 0 } | |
1241 | }; | |
1242 | ||
1243 | static ctl_table mq_sysctl_dir[] = { | |
1244 | { | |
1245 | .procname = "mqueue", | |
1246 | .mode = 0555, | |
1247 | .child = mq_sysctls, | |
1248 | }, | |
1249 | { .ctl_name = 0 } | |
1250 | }; | |
1251 | ||
1252 | static ctl_table mq_sysctl_root[] = { | |
1253 | { | |
1254 | .ctl_name = CTL_FS, | |
1255 | .procname = "fs", | |
1256 | .mode = 0555, | |
1257 | .child = mq_sysctl_dir, | |
1258 | }, | |
1259 | { .ctl_name = 0 } | |
1260 | }; | |
1261 | ||
1262 | static int __init init_mqueue_fs(void) | |
1263 | { | |
1264 | int error; | |
1265 | ||
1266 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", | |
1267 | sizeof(struct mqueue_inode_info), 0, | |
1268 | SLAB_HWCACHE_ALIGN, init_once); | |
1269 | if (mqueue_inode_cachep == NULL) | |
1270 | return -ENOMEM; | |
1271 | ||
1272 | /* ignore failues - they are not fatal */ | |
1273 | mq_sysctl_table = register_sysctl_table(mq_sysctl_root); | |
1274 | ||
1275 | error = register_filesystem(&mqueue_fs_type); | |
1276 | if (error) | |
1277 | goto out_sysctl; | |
1278 | ||
1279 | if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) { | |
1280 | error = PTR_ERR(mqueue_mnt); | |
1281 | goto out_filesystem; | |
1282 | } | |
1283 | ||
1284 | /* internal initialization - not common for vfs */ | |
1285 | queues_count = 0; | |
1286 | spin_lock_init(&mq_lock); | |
1287 | ||
1288 | return 0; | |
1289 | ||
1290 | out_filesystem: | |
1291 | unregister_filesystem(&mqueue_fs_type); | |
1292 | out_sysctl: | |
1293 | if (mq_sysctl_table) | |
1294 | unregister_sysctl_table(mq_sysctl_table); | |
1295 | kmem_cache_destroy(mqueue_inode_cachep); | |
1296 | return error; | |
1297 | } | |
1298 | ||
1299 | __initcall(init_mqueue_fs); |