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) | |
65163fd7 | 5 | * Michal Wronski (Michal.Wronski@motorola.com) |
1da177e4 LT |
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 | ||
c59ede7b | 14 | #include <linux/capability.h> |
1da177e4 LT |
15 | #include <linux/init.h> |
16 | #include <linux/pagemap.h> | |
17 | #include <linux/file.h> | |
18 | #include <linux/mount.h> | |
19 | #include <linux/namei.h> | |
20 | #include <linux/sysctl.h> | |
21 | #include <linux/poll.h> | |
22 | #include <linux/mqueue.h> | |
23 | #include <linux/msg.h> | |
24 | #include <linux/skbuff.h> | |
25 | #include <linux/netlink.h> | |
26 | #include <linux/syscalls.h> | |
7ed20e1a | 27 | #include <linux/signal.h> |
1da177e4 LT |
28 | #include <net/sock.h> |
29 | #include "util.h" | |
30 | ||
31 | #define MQUEUE_MAGIC 0x19800202 | |
32 | #define DIRENT_SIZE 20 | |
33 | #define FILENT_SIZE 80 | |
34 | ||
35 | #define SEND 0 | |
36 | #define RECV 1 | |
37 | ||
38 | #define STATE_NONE 0 | |
39 | #define STATE_PENDING 1 | |
40 | #define STATE_READY 2 | |
41 | ||
42 | /* used by sysctl */ | |
43 | #define FS_MQUEUE 1 | |
44 | #define CTL_QUEUESMAX 2 | |
45 | #define CTL_MSGMAX 3 | |
46 | #define CTL_MSGSIZEMAX 4 | |
47 | ||
48 | /* default values */ | |
49 | #define DFLT_QUEUESMAX 256 /* max number of message queues */ | |
50 | #define DFLT_MSGMAX 10 /* max number of messages in each queue */ | |
51 | #define HARD_MSGMAX (131072/sizeof(void*)) | |
52 | #define DFLT_MSGSIZEMAX 8192 /* max message size */ | |
53 | ||
54 | #define NOTIFY_COOKIE_LEN 32 | |
55 | ||
56 | struct ext_wait_queue { /* queue of sleeping tasks */ | |
57 | struct task_struct *task; | |
58 | struct list_head list; | |
59 | struct msg_msg *msg; /* ptr of loaded message */ | |
60 | int state; /* one of STATE_* values */ | |
61 | }; | |
62 | ||
63 | struct mqueue_inode_info { | |
64 | spinlock_t lock; | |
65 | struct inode vfs_inode; | |
66 | wait_queue_head_t wait_q; | |
67 | ||
68 | struct msg_msg **messages; | |
69 | struct mq_attr attr; | |
70 | ||
71 | struct sigevent notify; | |
72 | pid_t notify_owner; | |
338cec32 | 73 | struct user_struct *user; /* user who created, for accounting */ |
1da177e4 LT |
74 | struct sock *notify_sock; |
75 | struct sk_buff *notify_cookie; | |
76 | ||
77 | /* for tasks waiting for free space and messages, respectively */ | |
78 | struct ext_wait_queue e_wait_q[2]; | |
79 | ||
80 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ | |
81 | }; | |
82 | ||
83 | static struct inode_operations mqueue_dir_inode_operations; | |
84 | static struct file_operations mqueue_file_operations; | |
85 | static struct super_operations mqueue_super_ops; | |
86 | static void remove_notification(struct mqueue_inode_info *info); | |
87 | ||
88 | static spinlock_t mq_lock; | |
89 | static kmem_cache_t *mqueue_inode_cachep; | |
90 | static struct vfsmount *mqueue_mnt; | |
91 | ||
92 | static unsigned int queues_count; | |
93 | static unsigned int queues_max = DFLT_QUEUESMAX; | |
94 | static unsigned int msg_max = DFLT_MSGMAX; | |
95 | static unsigned int msgsize_max = DFLT_MSGSIZEMAX; | |
96 | ||
97 | static struct ctl_table_header * mq_sysctl_table; | |
98 | ||
99 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) | |
100 | { | |
101 | return container_of(inode, struct mqueue_inode_info, vfs_inode); | |
102 | } | |
103 | ||
104 | static struct inode *mqueue_get_inode(struct super_block *sb, int mode, | |
105 | struct mq_attr *attr) | |
106 | { | |
107 | struct inode *inode; | |
108 | ||
109 | inode = new_inode(sb); | |
110 | if (inode) { | |
111 | inode->i_mode = mode; | |
112 | inode->i_uid = current->fsuid; | |
113 | inode->i_gid = current->fsgid; | |
114 | inode->i_blksize = PAGE_CACHE_SIZE; | |
115 | inode->i_blocks = 0; | |
116 | inode->i_mtime = inode->i_ctime = inode->i_atime = | |
117 | CURRENT_TIME; | |
118 | ||
119 | if (S_ISREG(mode)) { | |
120 | struct mqueue_inode_info *info; | |
121 | struct task_struct *p = current; | |
122 | struct user_struct *u = p->user; | |
123 | unsigned long mq_bytes, mq_msg_tblsz; | |
124 | ||
125 | inode->i_fop = &mqueue_file_operations; | |
126 | inode->i_size = FILENT_SIZE; | |
127 | /* mqueue specific info */ | |
128 | info = MQUEUE_I(inode); | |
129 | spin_lock_init(&info->lock); | |
130 | init_waitqueue_head(&info->wait_q); | |
131 | INIT_LIST_HEAD(&info->e_wait_q[0].list); | |
132 | INIT_LIST_HEAD(&info->e_wait_q[1].list); | |
133 | info->messages = NULL; | |
134 | info->notify_owner = 0; | |
135 | info->qsize = 0; | |
136 | info->user = NULL; /* set when all is ok */ | |
137 | memset(&info->attr, 0, sizeof(info->attr)); | |
138 | info->attr.mq_maxmsg = DFLT_MSGMAX; | |
139 | info->attr.mq_msgsize = DFLT_MSGSIZEMAX; | |
140 | if (attr) { | |
141 | info->attr.mq_maxmsg = attr->mq_maxmsg; | |
142 | info->attr.mq_msgsize = attr->mq_msgsize; | |
143 | } | |
144 | mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *); | |
145 | mq_bytes = (mq_msg_tblsz + | |
146 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
147 | ||
148 | spin_lock(&mq_lock); | |
149 | if (u->mq_bytes + mq_bytes < u->mq_bytes || | |
150 | u->mq_bytes + mq_bytes > | |
151 | p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) { | |
152 | spin_unlock(&mq_lock); | |
153 | goto out_inode; | |
154 | } | |
155 | u->mq_bytes += mq_bytes; | |
156 | spin_unlock(&mq_lock); | |
157 | ||
158 | info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL); | |
159 | if (!info->messages) { | |
160 | spin_lock(&mq_lock); | |
161 | u->mq_bytes -= mq_bytes; | |
162 | spin_unlock(&mq_lock); | |
163 | goto out_inode; | |
164 | } | |
165 | /* all is ok */ | |
166 | info->user = get_uid(u); | |
167 | } else if (S_ISDIR(mode)) { | |
168 | inode->i_nlink++; | |
169 | /* Some things misbehave if size == 0 on a directory */ | |
170 | inode->i_size = 2 * DIRENT_SIZE; | |
171 | inode->i_op = &mqueue_dir_inode_operations; | |
172 | inode->i_fop = &simple_dir_operations; | |
173 | } | |
174 | } | |
175 | return inode; | |
176 | out_inode: | |
177 | make_bad_inode(inode); | |
178 | iput(inode); | |
179 | return NULL; | |
180 | } | |
181 | ||
182 | static int mqueue_fill_super(struct super_block *sb, void *data, int silent) | |
183 | { | |
184 | struct inode *inode; | |
185 | ||
186 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
187 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
188 | sb->s_magic = MQUEUE_MAGIC; | |
189 | sb->s_op = &mqueue_super_ops; | |
190 | ||
191 | inode = mqueue_get_inode(sb, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); | |
192 | if (!inode) | |
193 | return -ENOMEM; | |
194 | ||
195 | sb->s_root = d_alloc_root(inode); | |
196 | if (!sb->s_root) { | |
197 | iput(inode); | |
198 | return -ENOMEM; | |
199 | } | |
200 | ||
201 | return 0; | |
202 | } | |
203 | ||
204 | static struct super_block *mqueue_get_sb(struct file_system_type *fs_type, | |
205 | int flags, const char *dev_name, | |
206 | void *data) | |
207 | { | |
208 | return get_sb_single(fs_type, flags, data, mqueue_fill_super); | |
209 | } | |
210 | ||
211 | static void init_once(void *foo, kmem_cache_t * cachep, unsigned long flags) | |
212 | { | |
213 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; | |
214 | ||
215 | if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) == | |
216 | SLAB_CTOR_CONSTRUCTOR) | |
217 | inode_init_once(&p->vfs_inode); | |
218 | } | |
219 | ||
220 | static struct inode *mqueue_alloc_inode(struct super_block *sb) | |
221 | { | |
222 | struct mqueue_inode_info *ei; | |
223 | ||
224 | ei = kmem_cache_alloc(mqueue_inode_cachep, SLAB_KERNEL); | |
225 | if (!ei) | |
226 | return NULL; | |
227 | return &ei->vfs_inode; | |
228 | } | |
229 | ||
230 | static void mqueue_destroy_inode(struct inode *inode) | |
231 | { | |
232 | kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); | |
233 | } | |
234 | ||
235 | static void mqueue_delete_inode(struct inode *inode) | |
236 | { | |
237 | struct mqueue_inode_info *info; | |
238 | struct user_struct *user; | |
239 | unsigned long mq_bytes; | |
240 | int i; | |
241 | ||
242 | if (S_ISDIR(inode->i_mode)) { | |
243 | clear_inode(inode); | |
244 | return; | |
245 | } | |
246 | info = MQUEUE_I(inode); | |
247 | spin_lock(&info->lock); | |
248 | for (i = 0; i < info->attr.mq_curmsgs; i++) | |
249 | free_msg(info->messages[i]); | |
250 | kfree(info->messages); | |
251 | spin_unlock(&info->lock); | |
252 | ||
253 | clear_inode(inode); | |
254 | ||
255 | mq_bytes = (info->attr.mq_maxmsg * sizeof(struct msg_msg *) + | |
256 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
257 | user = info->user; | |
258 | if (user) { | |
259 | spin_lock(&mq_lock); | |
260 | user->mq_bytes -= mq_bytes; | |
261 | queues_count--; | |
262 | spin_unlock(&mq_lock); | |
263 | free_uid(user); | |
264 | } | |
265 | } | |
266 | ||
267 | static int mqueue_create(struct inode *dir, struct dentry *dentry, | |
268 | int mode, struct nameidata *nd) | |
269 | { | |
270 | struct inode *inode; | |
271 | struct mq_attr *attr = dentry->d_fsdata; | |
272 | int error; | |
273 | ||
274 | spin_lock(&mq_lock); | |
275 | if (queues_count >= queues_max && !capable(CAP_SYS_RESOURCE)) { | |
276 | error = -ENOSPC; | |
277 | goto out_lock; | |
278 | } | |
279 | queues_count++; | |
280 | spin_unlock(&mq_lock); | |
281 | ||
282 | inode = mqueue_get_inode(dir->i_sb, mode, attr); | |
283 | if (!inode) { | |
284 | error = -ENOMEM; | |
285 | spin_lock(&mq_lock); | |
286 | queues_count--; | |
287 | goto out_lock; | |
288 | } | |
289 | ||
290 | dir->i_size += DIRENT_SIZE; | |
291 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
292 | ||
293 | d_instantiate(dentry, inode); | |
294 | dget(dentry); | |
295 | return 0; | |
296 | out_lock: | |
297 | spin_unlock(&mq_lock); | |
298 | return error; | |
299 | } | |
300 | ||
301 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) | |
302 | { | |
303 | struct inode *inode = dentry->d_inode; | |
304 | ||
305 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
306 | dir->i_size -= DIRENT_SIZE; | |
307 | inode->i_nlink--; | |
308 | dput(dentry); | |
309 | return 0; | |
310 | } | |
311 | ||
312 | /* | |
313 | * This is routine for system read from queue file. | |
314 | * To avoid mess with doing here some sort of mq_receive we allow | |
315 | * to read only queue size & notification info (the only values | |
316 | * that are interesting from user point of view and aren't accessible | |
317 | * through std routines) | |
318 | */ | |
319 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, | |
320 | size_t count, loff_t * off) | |
321 | { | |
322 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode); | |
323 | char buffer[FILENT_SIZE]; | |
324 | size_t slen; | |
325 | loff_t o; | |
326 | ||
327 | if (!count) | |
328 | return 0; | |
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 | info->notify_owner); | |
339 | spin_unlock(&info->lock); | |
340 | buffer[sizeof(buffer)-1] = '\0'; | |
341 | slen = strlen(buffer)+1; | |
342 | ||
343 | o = *off; | |
344 | if (o > slen) | |
345 | return 0; | |
346 | ||
347 | if (o + count > slen) | |
348 | count = slen - o; | |
349 | ||
350 | if (copy_to_user(u_data, buffer + o, count)) | |
351 | return -EFAULT; | |
352 | ||
353 | *off = o + count; | |
354 | filp->f_dentry->d_inode->i_atime = filp->f_dentry->d_inode->i_ctime = CURRENT_TIME; | |
355 | return count; | |
356 | } | |
357 | ||
358 | static int mqueue_flush_file(struct file *filp) | |
359 | { | |
360 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode); | |
361 | ||
362 | spin_lock(&info->lock); | |
363 | if (current->tgid == info->notify_owner) | |
364 | remove_notification(info); | |
365 | ||
366 | spin_unlock(&info->lock); | |
367 | return 0; | |
368 | } | |
369 | ||
370 | static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) | |
371 | { | |
372 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode); | |
373 | int retval = 0; | |
374 | ||
375 | poll_wait(filp, &info->wait_q, poll_tab); | |
376 | ||
377 | spin_lock(&info->lock); | |
378 | if (info->attr.mq_curmsgs) | |
379 | retval = POLLIN | POLLRDNORM; | |
380 | ||
381 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) | |
382 | retval |= POLLOUT | POLLWRNORM; | |
383 | spin_unlock(&info->lock); | |
384 | ||
385 | return retval; | |
386 | } | |
387 | ||
388 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ | |
389 | static void wq_add(struct mqueue_inode_info *info, int sr, | |
390 | struct ext_wait_queue *ewp) | |
391 | { | |
392 | struct ext_wait_queue *walk; | |
393 | ||
394 | ewp->task = current; | |
395 | ||
396 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { | |
397 | if (walk->task->static_prio <= current->static_prio) { | |
398 | list_add_tail(&ewp->list, &walk->list); | |
399 | return; | |
400 | } | |
401 | } | |
402 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); | |
403 | } | |
404 | ||
405 | /* | |
406 | * Puts current task to sleep. Caller must hold queue lock. After return | |
407 | * lock isn't held. | |
408 | * sr: SEND or RECV | |
409 | */ | |
410 | static int wq_sleep(struct mqueue_inode_info *info, int sr, | |
411 | long timeout, struct ext_wait_queue *ewp) | |
412 | { | |
413 | int retval; | |
414 | signed long time; | |
415 | ||
416 | wq_add(info, sr, ewp); | |
417 | ||
418 | for (;;) { | |
419 | set_current_state(TASK_INTERRUPTIBLE); | |
420 | ||
421 | spin_unlock(&info->lock); | |
422 | time = schedule_timeout(timeout); | |
423 | ||
424 | while (ewp->state == STATE_PENDING) | |
425 | cpu_relax(); | |
426 | ||
427 | if (ewp->state == STATE_READY) { | |
428 | retval = 0; | |
429 | goto out; | |
430 | } | |
431 | spin_lock(&info->lock); | |
432 | if (ewp->state == STATE_READY) { | |
433 | retval = 0; | |
434 | goto out_unlock; | |
435 | } | |
436 | if (signal_pending(current)) { | |
437 | retval = -ERESTARTSYS; | |
438 | break; | |
439 | } | |
440 | if (time == 0) { | |
441 | retval = -ETIMEDOUT; | |
442 | break; | |
443 | } | |
444 | } | |
445 | list_del(&ewp->list); | |
446 | out_unlock: | |
447 | spin_unlock(&info->lock); | |
448 | out: | |
449 | return retval; | |
450 | } | |
451 | ||
452 | /* | |
453 | * Returns waiting task that should be serviced first or NULL if none exists | |
454 | */ | |
455 | static struct ext_wait_queue *wq_get_first_waiter( | |
456 | struct mqueue_inode_info *info, int sr) | |
457 | { | |
458 | struct list_head *ptr; | |
459 | ||
460 | ptr = info->e_wait_q[sr].list.prev; | |
461 | if (ptr == &info->e_wait_q[sr].list) | |
462 | return NULL; | |
463 | return list_entry(ptr, struct ext_wait_queue, list); | |
464 | } | |
465 | ||
466 | /* Auxiliary functions to manipulate messages' list */ | |
467 | static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info) | |
468 | { | |
469 | int k; | |
470 | ||
471 | k = info->attr.mq_curmsgs - 1; | |
472 | while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) { | |
473 | info->messages[k + 1] = info->messages[k]; | |
474 | k--; | |
475 | } | |
476 | info->attr.mq_curmsgs++; | |
477 | info->qsize += ptr->m_ts; | |
478 | info->messages[k + 1] = ptr; | |
479 | } | |
480 | ||
481 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) | |
482 | { | |
483 | info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts; | |
484 | return info->messages[info->attr.mq_curmsgs]; | |
485 | } | |
486 | ||
487 | static inline void set_cookie(struct sk_buff *skb, char code) | |
488 | { | |
489 | ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; | |
490 | } | |
491 | ||
492 | /* | |
493 | * The next function is only to split too long sys_mq_timedsend | |
494 | */ | |
495 | static void __do_notify(struct mqueue_inode_info *info) | |
496 | { | |
497 | /* notification | |
498 | * invoked when there is registered process and there isn't process | |
499 | * waiting synchronously for message AND state of queue changed from | |
500 | * empty to not empty. Here we are sure that no one is waiting | |
501 | * synchronously. */ | |
502 | if (info->notify_owner && | |
503 | info->attr.mq_curmsgs == 1) { | |
504 | struct siginfo sig_i; | |
505 | switch (info->notify.sigev_notify) { | |
506 | case SIGEV_NONE: | |
507 | break; | |
508 | case SIGEV_SIGNAL: | |
509 | /* sends signal */ | |
510 | ||
511 | sig_i.si_signo = info->notify.sigev_signo; | |
512 | sig_i.si_errno = 0; | |
513 | sig_i.si_code = SI_MESGQ; | |
514 | sig_i.si_value = info->notify.sigev_value; | |
515 | sig_i.si_pid = current->tgid; | |
516 | sig_i.si_uid = current->uid; | |
517 | ||
518 | kill_proc_info(info->notify.sigev_signo, | |
519 | &sig_i, info->notify_owner); | |
520 | break; | |
521 | case SIGEV_THREAD: | |
522 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); | |
523 | netlink_sendskb(info->notify_sock, | |
524 | info->notify_cookie, 0); | |
525 | break; | |
526 | } | |
527 | /* after notification unregisters process */ | |
528 | info->notify_owner = 0; | |
529 | } | |
530 | wake_up(&info->wait_q); | |
531 | } | |
532 | ||
533 | static long prepare_timeout(const struct timespec __user *u_arg) | |
534 | { | |
535 | struct timespec ts, nowts; | |
536 | long timeout; | |
537 | ||
538 | if (u_arg) { | |
539 | if (unlikely(copy_from_user(&ts, u_arg, | |
540 | sizeof(struct timespec)))) | |
541 | return -EFAULT; | |
542 | ||
543 | if (unlikely(ts.tv_nsec < 0 || ts.tv_sec < 0 | |
544 | || ts.tv_nsec >= NSEC_PER_SEC)) | |
545 | return -EINVAL; | |
546 | nowts = CURRENT_TIME; | |
547 | /* first subtract as jiffies can't be too big */ | |
548 | ts.tv_sec -= nowts.tv_sec; | |
549 | if (ts.tv_nsec < nowts.tv_nsec) { | |
550 | ts.tv_nsec += NSEC_PER_SEC; | |
551 | ts.tv_sec--; | |
552 | } | |
553 | ts.tv_nsec -= nowts.tv_nsec; | |
554 | if (ts.tv_sec < 0) | |
555 | return 0; | |
556 | ||
557 | timeout = timespec_to_jiffies(&ts) + 1; | |
558 | } else | |
559 | return MAX_SCHEDULE_TIMEOUT; | |
560 | ||
561 | return timeout; | |
562 | } | |
563 | ||
564 | static void remove_notification(struct mqueue_inode_info *info) | |
565 | { | |
566 | if (info->notify_owner != 0 && | |
567 | info->notify.sigev_notify == SIGEV_THREAD) { | |
568 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); | |
569 | netlink_sendskb(info->notify_sock, info->notify_cookie, 0); | |
570 | } | |
571 | info->notify_owner = 0; | |
572 | } | |
573 | ||
574 | static int mq_attr_ok(struct mq_attr *attr) | |
575 | { | |
576 | if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) | |
577 | return 0; | |
578 | if (capable(CAP_SYS_RESOURCE)) { | |
579 | if (attr->mq_maxmsg > HARD_MSGMAX) | |
580 | return 0; | |
581 | } else { | |
582 | if (attr->mq_maxmsg > msg_max || | |
583 | attr->mq_msgsize > msgsize_max) | |
584 | return 0; | |
585 | } | |
586 | /* check for overflow */ | |
587 | if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) | |
588 | return 0; | |
589 | if ((unsigned long)(attr->mq_maxmsg * attr->mq_msgsize) + | |
590 | (attr->mq_maxmsg * sizeof (struct msg_msg *)) < | |
591 | (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize)) | |
592 | return 0; | |
593 | return 1; | |
594 | } | |
595 | ||
596 | /* | |
597 | * Invoked when creating a new queue via sys_mq_open | |
598 | */ | |
599 | static struct file *do_create(struct dentry *dir, struct dentry *dentry, | |
600 | int oflag, mode_t mode, struct mq_attr __user *u_attr) | |
601 | { | |
1da177e4 LT |
602 | struct mq_attr attr; |
603 | int ret; | |
604 | ||
7c7dce92 AV |
605 | if (u_attr) { |
606 | ret = -EFAULT; | |
1da177e4 | 607 | if (copy_from_user(&attr, u_attr, sizeof(attr))) |
7c7dce92 AV |
608 | goto out; |
609 | ret = -EINVAL; | |
1da177e4 | 610 | if (!mq_attr_ok(&attr)) |
7c7dce92 | 611 | goto out; |
1da177e4 LT |
612 | /* store for use during create */ |
613 | dentry->d_fsdata = &attr; | |
614 | } | |
615 | ||
59175839 | 616 | mode &= ~current->fs->umask; |
1da177e4 LT |
617 | ret = vfs_create(dir->d_inode, dentry, mode, NULL); |
618 | dentry->d_fsdata = NULL; | |
619 | if (ret) | |
7c7dce92 | 620 | goto out; |
1da177e4 | 621 | |
7c7dce92 | 622 | return dentry_open(dentry, mqueue_mnt, oflag); |
1da177e4 | 623 | |
7c7dce92 AV |
624 | out: |
625 | dput(dentry); | |
626 | mntput(mqueue_mnt); | |
627 | return ERR_PTR(ret); | |
1da177e4 LT |
628 | } |
629 | ||
630 | /* Opens existing queue */ | |
631 | static struct file *do_open(struct dentry *dentry, int oflag) | |
632 | { | |
633 | static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, | |
634 | MAY_READ | MAY_WRITE }; | |
1da177e4 | 635 | |
7c7dce92 AV |
636 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { |
637 | dput(dentry); | |
638 | mntput(mqueue_mnt); | |
1da177e4 | 639 | return ERR_PTR(-EINVAL); |
7c7dce92 | 640 | } |
1da177e4 | 641 | |
7c7dce92 AV |
642 | if (permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE], NULL)) { |
643 | dput(dentry); | |
644 | mntput(mqueue_mnt); | |
1da177e4 | 645 | return ERR_PTR(-EACCES); |
7c7dce92 | 646 | } |
1da177e4 | 647 | |
7c7dce92 | 648 | return dentry_open(dentry, mqueue_mnt, oflag); |
1da177e4 LT |
649 | } |
650 | ||
651 | asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode, | |
652 | struct mq_attr __user *u_attr) | |
653 | { | |
654 | struct dentry *dentry; | |
655 | struct file *filp; | |
656 | char *name; | |
657 | int fd, error; | |
658 | ||
659 | if (IS_ERR(name = getname(u_name))) | |
660 | return PTR_ERR(name); | |
661 | ||
662 | fd = get_unused_fd(); | |
663 | if (fd < 0) | |
664 | goto out_putname; | |
665 | ||
1b1dcc1b | 666 | mutex_lock(&mqueue_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
667 | dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name)); |
668 | if (IS_ERR(dentry)) { | |
669 | error = PTR_ERR(dentry); | |
670 | goto out_err; | |
671 | } | |
672 | mntget(mqueue_mnt); | |
673 | ||
674 | if (oflag & O_CREAT) { | |
675 | if (dentry->d_inode) { /* entry already exists */ | |
7c7dce92 AV |
676 | error = -EEXIST; |
677 | if (oflag & O_EXCL) | |
678 | goto out; | |
679 | filp = do_open(dentry, oflag); | |
1da177e4 LT |
680 | } else { |
681 | filp = do_create(mqueue_mnt->mnt_root, dentry, | |
682 | oflag, mode, u_attr); | |
683 | } | |
7c7dce92 AV |
684 | } else { |
685 | error = -ENOENT; | |
686 | if (!dentry->d_inode) | |
687 | goto out; | |
688 | filp = do_open(dentry, oflag); | |
689 | } | |
1da177e4 LT |
690 | |
691 | if (IS_ERR(filp)) { | |
692 | error = PTR_ERR(filp); | |
693 | goto out_putfd; | |
694 | } | |
695 | ||
696 | set_close_on_exec(fd, 1); | |
697 | fd_install(fd, filp); | |
698 | goto out_upsem; | |
699 | ||
7c7dce92 AV |
700 | out: |
701 | dput(dentry); | |
1da177e4 | 702 | mntput(mqueue_mnt); |
7c7dce92 | 703 | out_putfd: |
1da177e4 LT |
704 | put_unused_fd(fd); |
705 | out_err: | |
706 | fd = error; | |
707 | out_upsem: | |
1b1dcc1b | 708 | mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
709 | out_putname: |
710 | putname(name); | |
711 | return fd; | |
712 | } | |
713 | ||
714 | asmlinkage long sys_mq_unlink(const char __user *u_name) | |
715 | { | |
716 | int err; | |
717 | char *name; | |
718 | struct dentry *dentry; | |
719 | struct inode *inode = NULL; | |
720 | ||
721 | name = getname(u_name); | |
722 | if (IS_ERR(name)) | |
723 | return PTR_ERR(name); | |
724 | ||
1b1dcc1b | 725 | mutex_lock(&mqueue_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
726 | dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name)); |
727 | if (IS_ERR(dentry)) { | |
728 | err = PTR_ERR(dentry); | |
729 | goto out_unlock; | |
730 | } | |
731 | ||
732 | if (!dentry->d_inode) { | |
733 | err = -ENOENT; | |
734 | goto out_err; | |
735 | } | |
736 | ||
737 | inode = dentry->d_inode; | |
738 | if (inode) | |
739 | atomic_inc(&inode->i_count); | |
740 | ||
741 | err = vfs_unlink(dentry->d_parent->d_inode, dentry); | |
742 | out_err: | |
743 | dput(dentry); | |
744 | ||
745 | out_unlock: | |
1b1dcc1b | 746 | mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
747 | putname(name); |
748 | if (inode) | |
749 | iput(inode); | |
750 | ||
751 | return err; | |
752 | } | |
753 | ||
754 | /* Pipelined send and receive functions. | |
755 | * | |
756 | * If a receiver finds no waiting message, then it registers itself in the | |
757 | * list of waiting receivers. A sender checks that list before adding the new | |
758 | * message into the message array. If there is a waiting receiver, then it | |
759 | * bypasses the message array and directly hands the message over to the | |
760 | * receiver. | |
761 | * The receiver accepts the message and returns without grabbing the queue | |
762 | * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers | |
763 | * are necessary. The same algorithm is used for sysv semaphores, see | |
764 | * ipc/sem.c fore more details. | |
765 | * | |
766 | * The same algorithm is used for senders. | |
767 | */ | |
768 | ||
769 | /* pipelined_send() - send a message directly to the task waiting in | |
770 | * sys_mq_timedreceive() (without inserting message into a queue). | |
771 | */ | |
772 | static inline void pipelined_send(struct mqueue_inode_info *info, | |
773 | struct msg_msg *message, | |
774 | struct ext_wait_queue *receiver) | |
775 | { | |
776 | receiver->msg = message; | |
777 | list_del(&receiver->list); | |
778 | receiver->state = STATE_PENDING; | |
779 | wake_up_process(receiver->task); | |
d59dd462 | 780 | smp_wmb(); |
1da177e4 LT |
781 | receiver->state = STATE_READY; |
782 | } | |
783 | ||
784 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() | |
785 | * gets its message and put to the queue (we have one free place for sure). */ | |
786 | static inline void pipelined_receive(struct mqueue_inode_info *info) | |
787 | { | |
788 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); | |
789 | ||
790 | if (!sender) { | |
791 | /* for poll */ | |
792 | wake_up_interruptible(&info->wait_q); | |
793 | return; | |
794 | } | |
795 | msg_insert(sender->msg, info); | |
796 | list_del(&sender->list); | |
797 | sender->state = STATE_PENDING; | |
798 | wake_up_process(sender->task); | |
d59dd462 | 799 | smp_wmb(); |
1da177e4 LT |
800 | sender->state = STATE_READY; |
801 | } | |
802 | ||
803 | asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr, | |
804 | size_t msg_len, unsigned int msg_prio, | |
805 | const struct timespec __user *u_abs_timeout) | |
806 | { | |
807 | struct file *filp; | |
808 | struct inode *inode; | |
809 | struct ext_wait_queue wait; | |
810 | struct ext_wait_queue *receiver; | |
811 | struct msg_msg *msg_ptr; | |
812 | struct mqueue_inode_info *info; | |
813 | long timeout; | |
814 | int ret; | |
815 | ||
816 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) | |
817 | return -EINVAL; | |
818 | ||
819 | timeout = prepare_timeout(u_abs_timeout); | |
820 | ||
821 | ret = -EBADF; | |
822 | filp = fget(mqdes); | |
823 | if (unlikely(!filp)) | |
824 | goto out; | |
825 | ||
826 | inode = filp->f_dentry->d_inode; | |
827 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
828 | goto out_fput; | |
829 | info = MQUEUE_I(inode); | |
830 | ||
831 | if (unlikely(!(filp->f_mode & FMODE_WRITE))) | |
832 | goto out_fput; | |
833 | ||
834 | if (unlikely(msg_len > info->attr.mq_msgsize)) { | |
835 | ret = -EMSGSIZE; | |
836 | goto out_fput; | |
837 | } | |
838 | ||
839 | /* First try to allocate memory, before doing anything with | |
840 | * existing queues. */ | |
841 | msg_ptr = load_msg(u_msg_ptr, msg_len); | |
842 | if (IS_ERR(msg_ptr)) { | |
843 | ret = PTR_ERR(msg_ptr); | |
844 | goto out_fput; | |
845 | } | |
846 | msg_ptr->m_ts = msg_len; | |
847 | msg_ptr->m_type = msg_prio; | |
848 | ||
849 | spin_lock(&info->lock); | |
850 | ||
851 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { | |
852 | if (filp->f_flags & O_NONBLOCK) { | |
853 | spin_unlock(&info->lock); | |
854 | ret = -EAGAIN; | |
855 | } else if (unlikely(timeout < 0)) { | |
856 | spin_unlock(&info->lock); | |
857 | ret = timeout; | |
858 | } else { | |
859 | wait.task = current; | |
860 | wait.msg = (void *) msg_ptr; | |
861 | wait.state = STATE_NONE; | |
862 | ret = wq_sleep(info, SEND, timeout, &wait); | |
863 | } | |
864 | if (ret < 0) | |
865 | free_msg(msg_ptr); | |
866 | } else { | |
867 | receiver = wq_get_first_waiter(info, RECV); | |
868 | if (receiver) { | |
869 | pipelined_send(info, msg_ptr, receiver); | |
870 | } else { | |
871 | /* adds message to the queue */ | |
872 | msg_insert(msg_ptr, info); | |
873 | __do_notify(info); | |
874 | } | |
875 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
876 | CURRENT_TIME; | |
877 | spin_unlock(&info->lock); | |
878 | ret = 0; | |
879 | } | |
880 | out_fput: | |
881 | fput(filp); | |
882 | out: | |
883 | return ret; | |
884 | } | |
885 | ||
886 | asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr, | |
887 | size_t msg_len, unsigned int __user *u_msg_prio, | |
888 | const struct timespec __user *u_abs_timeout) | |
889 | { | |
890 | long timeout; | |
891 | ssize_t ret; | |
892 | struct msg_msg *msg_ptr; | |
893 | struct file *filp; | |
894 | struct inode *inode; | |
895 | struct mqueue_inode_info *info; | |
896 | struct ext_wait_queue wait; | |
897 | ||
898 | timeout = prepare_timeout(u_abs_timeout); | |
899 | ||
900 | ret = -EBADF; | |
901 | filp = fget(mqdes); | |
902 | if (unlikely(!filp)) | |
903 | goto out; | |
904 | ||
905 | inode = filp->f_dentry->d_inode; | |
906 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
907 | goto out_fput; | |
908 | info = MQUEUE_I(inode); | |
909 | ||
910 | if (unlikely(!(filp->f_mode & FMODE_READ))) | |
911 | goto out_fput; | |
912 | ||
913 | /* checks if buffer is big enough */ | |
914 | if (unlikely(msg_len < info->attr.mq_msgsize)) { | |
915 | ret = -EMSGSIZE; | |
916 | goto out_fput; | |
917 | } | |
918 | ||
919 | spin_lock(&info->lock); | |
920 | if (info->attr.mq_curmsgs == 0) { | |
921 | if (filp->f_flags & O_NONBLOCK) { | |
922 | spin_unlock(&info->lock); | |
923 | ret = -EAGAIN; | |
924 | msg_ptr = NULL; | |
925 | } else if (unlikely(timeout < 0)) { | |
926 | spin_unlock(&info->lock); | |
927 | ret = timeout; | |
928 | msg_ptr = NULL; | |
929 | } else { | |
930 | wait.task = current; | |
931 | wait.state = STATE_NONE; | |
932 | ret = wq_sleep(info, RECV, timeout, &wait); | |
933 | msg_ptr = wait.msg; | |
934 | } | |
935 | } else { | |
936 | msg_ptr = msg_get(info); | |
937 | ||
938 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
939 | CURRENT_TIME; | |
940 | ||
941 | /* There is now free space in queue. */ | |
942 | pipelined_receive(info); | |
943 | spin_unlock(&info->lock); | |
944 | ret = 0; | |
945 | } | |
946 | if (ret == 0) { | |
947 | ret = msg_ptr->m_ts; | |
948 | ||
949 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || | |
950 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { | |
951 | ret = -EFAULT; | |
952 | } | |
953 | free_msg(msg_ptr); | |
954 | } | |
955 | out_fput: | |
956 | fput(filp); | |
957 | out: | |
958 | return ret; | |
959 | } | |
960 | ||
961 | /* | |
962 | * Notes: the case when user wants us to deregister (with NULL as pointer) | |
963 | * and he isn't currently owner of notification, will be silently discarded. | |
964 | * It isn't explicitly defined in the POSIX. | |
965 | */ | |
966 | asmlinkage long sys_mq_notify(mqd_t mqdes, | |
967 | const struct sigevent __user *u_notification) | |
968 | { | |
969 | int ret; | |
970 | struct file *filp; | |
971 | struct sock *sock; | |
972 | struct inode *inode; | |
973 | struct sigevent notification; | |
974 | struct mqueue_inode_info *info; | |
975 | struct sk_buff *nc; | |
976 | ||
977 | nc = NULL; | |
978 | sock = NULL; | |
979 | if (u_notification != NULL) { | |
980 | if (copy_from_user(¬ification, u_notification, | |
981 | sizeof(struct sigevent))) | |
982 | return -EFAULT; | |
983 | ||
984 | if (unlikely(notification.sigev_notify != SIGEV_NONE && | |
985 | notification.sigev_notify != SIGEV_SIGNAL && | |
986 | notification.sigev_notify != SIGEV_THREAD)) | |
987 | return -EINVAL; | |
988 | if (notification.sigev_notify == SIGEV_SIGNAL && | |
7ed20e1a | 989 | !valid_signal(notification.sigev_signo)) { |
1da177e4 LT |
990 | return -EINVAL; |
991 | } | |
992 | if (notification.sigev_notify == SIGEV_THREAD) { | |
993 | /* create the notify skb */ | |
994 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); | |
995 | ret = -ENOMEM; | |
996 | if (!nc) | |
997 | goto out; | |
998 | ret = -EFAULT; | |
999 | if (copy_from_user(nc->data, | |
1000 | notification.sigev_value.sival_ptr, | |
1001 | NOTIFY_COOKIE_LEN)) { | |
1002 | goto out; | |
1003 | } | |
1004 | ||
1005 | /* TODO: add a header? */ | |
1006 | skb_put(nc, NOTIFY_COOKIE_LEN); | |
1007 | /* and attach it to the socket */ | |
1008 | retry: | |
1009 | filp = fget(notification.sigev_signo); | |
1010 | ret = -EBADF; | |
1011 | if (!filp) | |
1012 | goto out; | |
1013 | sock = netlink_getsockbyfilp(filp); | |
1014 | fput(filp); | |
1015 | if (IS_ERR(sock)) { | |
1016 | ret = PTR_ERR(sock); | |
1017 | sock = NULL; | |
1018 | goto out; | |
1019 | } | |
1020 | ||
a70ea994 AK |
1021 | ret = netlink_attachskb(sock, nc, 0, |
1022 | MAX_SCHEDULE_TIMEOUT, NULL); | |
1da177e4 LT |
1023 | if (ret == 1) |
1024 | goto retry; | |
1025 | if (ret) { | |
1026 | sock = NULL; | |
1027 | nc = NULL; | |
1028 | goto out; | |
1029 | } | |
1030 | } | |
1031 | } | |
1032 | ||
1033 | ret = -EBADF; | |
1034 | filp = fget(mqdes); | |
1035 | if (!filp) | |
1036 | goto out; | |
1037 | ||
1038 | inode = filp->f_dentry->d_inode; | |
1039 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
1040 | goto out_fput; | |
1041 | info = MQUEUE_I(inode); | |
1042 | ||
1043 | ret = 0; | |
1044 | spin_lock(&info->lock); | |
1045 | if (u_notification == NULL) { | |
1046 | if (info->notify_owner == current->tgid) { | |
1047 | remove_notification(info); | |
1048 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1049 | } | |
1050 | } else if (info->notify_owner != 0) { | |
1051 | ret = -EBUSY; | |
1052 | } else { | |
1053 | switch (notification.sigev_notify) { | |
1054 | case SIGEV_NONE: | |
1055 | info->notify.sigev_notify = SIGEV_NONE; | |
1056 | break; | |
1057 | case SIGEV_THREAD: | |
1058 | info->notify_sock = sock; | |
1059 | info->notify_cookie = nc; | |
1060 | sock = NULL; | |
1061 | nc = NULL; | |
1062 | info->notify.sigev_notify = SIGEV_THREAD; | |
1063 | break; | |
1064 | case SIGEV_SIGNAL: | |
1065 | info->notify.sigev_signo = notification.sigev_signo; | |
1066 | info->notify.sigev_value = notification.sigev_value; | |
1067 | info->notify.sigev_notify = SIGEV_SIGNAL; | |
1068 | break; | |
1069 | } | |
1070 | info->notify_owner = current->tgid; | |
1071 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1072 | } | |
1073 | spin_unlock(&info->lock); | |
1074 | out_fput: | |
1075 | fput(filp); | |
1076 | out: | |
1077 | if (sock) { | |
1078 | netlink_detachskb(sock, nc); | |
1079 | } else if (nc) { | |
1080 | dev_kfree_skb(nc); | |
1081 | } | |
1082 | return ret; | |
1083 | } | |
1084 | ||
1085 | asmlinkage long sys_mq_getsetattr(mqd_t mqdes, | |
1086 | const struct mq_attr __user *u_mqstat, | |
1087 | struct mq_attr __user *u_omqstat) | |
1088 | { | |
1089 | int ret; | |
1090 | struct mq_attr mqstat, omqstat; | |
1091 | struct file *filp; | |
1092 | struct inode *inode; | |
1093 | struct mqueue_inode_info *info; | |
1094 | ||
1095 | if (u_mqstat != NULL) { | |
1096 | if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) | |
1097 | return -EFAULT; | |
1098 | if (mqstat.mq_flags & (~O_NONBLOCK)) | |
1099 | return -EINVAL; | |
1100 | } | |
1101 | ||
1102 | ret = -EBADF; | |
1103 | filp = fget(mqdes); | |
1104 | if (!filp) | |
1105 | goto out; | |
1106 | ||
1107 | inode = filp->f_dentry->d_inode; | |
1108 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
1109 | goto out_fput; | |
1110 | info = MQUEUE_I(inode); | |
1111 | ||
1112 | spin_lock(&info->lock); | |
1113 | ||
1114 | omqstat = info->attr; | |
1115 | omqstat.mq_flags = filp->f_flags & O_NONBLOCK; | |
1116 | if (u_mqstat) { | |
1117 | if (mqstat.mq_flags & O_NONBLOCK) | |
1118 | filp->f_flags |= O_NONBLOCK; | |
1119 | else | |
1120 | filp->f_flags &= ~O_NONBLOCK; | |
1121 | ||
1122 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1123 | } | |
1124 | ||
1125 | spin_unlock(&info->lock); | |
1126 | ||
1127 | ret = 0; | |
1128 | if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, | |
1129 | sizeof(struct mq_attr))) | |
1130 | ret = -EFAULT; | |
1131 | ||
1132 | out_fput: | |
1133 | fput(filp); | |
1134 | out: | |
1135 | return ret; | |
1136 | } | |
1137 | ||
1138 | static struct inode_operations mqueue_dir_inode_operations = { | |
1139 | .lookup = simple_lookup, | |
1140 | .create = mqueue_create, | |
1141 | .unlink = mqueue_unlink, | |
1142 | }; | |
1143 | ||
1144 | static struct file_operations mqueue_file_operations = { | |
1145 | .flush = mqueue_flush_file, | |
1146 | .poll = mqueue_poll_file, | |
1147 | .read = mqueue_read_file, | |
1148 | }; | |
1149 | ||
1150 | static struct super_operations mqueue_super_ops = { | |
1151 | .alloc_inode = mqueue_alloc_inode, | |
1152 | .destroy_inode = mqueue_destroy_inode, | |
1153 | .statfs = simple_statfs, | |
1154 | .delete_inode = mqueue_delete_inode, | |
1155 | .drop_inode = generic_delete_inode, | |
1156 | }; | |
1157 | ||
1158 | static struct file_system_type mqueue_fs_type = { | |
1159 | .name = "mqueue", | |
1160 | .get_sb = mqueue_get_sb, | |
1161 | .kill_sb = kill_litter_super, | |
1162 | }; | |
1163 | ||
1164 | static int msg_max_limit_min = DFLT_MSGMAX; | |
1165 | static int msg_max_limit_max = HARD_MSGMAX; | |
1166 | ||
1167 | static int msg_maxsize_limit_min = DFLT_MSGSIZEMAX; | |
1168 | static int msg_maxsize_limit_max = INT_MAX; | |
1169 | ||
1170 | static ctl_table mq_sysctls[] = { | |
1171 | { | |
1172 | .ctl_name = CTL_QUEUESMAX, | |
1173 | .procname = "queues_max", | |
1174 | .data = &queues_max, | |
1175 | .maxlen = sizeof(int), | |
1176 | .mode = 0644, | |
1177 | .proc_handler = &proc_dointvec, | |
1178 | }, | |
1179 | { | |
1180 | .ctl_name = CTL_MSGMAX, | |
1181 | .procname = "msg_max", | |
1182 | .data = &msg_max, | |
1183 | .maxlen = sizeof(int), | |
1184 | .mode = 0644, | |
1185 | .proc_handler = &proc_dointvec_minmax, | |
1186 | .extra1 = &msg_max_limit_min, | |
1187 | .extra2 = &msg_max_limit_max, | |
1188 | }, | |
1189 | { | |
1190 | .ctl_name = CTL_MSGSIZEMAX, | |
1191 | .procname = "msgsize_max", | |
1192 | .data = &msgsize_max, | |
1193 | .maxlen = sizeof(int), | |
1194 | .mode = 0644, | |
1195 | .proc_handler = &proc_dointvec_minmax, | |
1196 | .extra1 = &msg_maxsize_limit_min, | |
1197 | .extra2 = &msg_maxsize_limit_max, | |
1198 | }, | |
1199 | { .ctl_name = 0 } | |
1200 | }; | |
1201 | ||
1202 | static ctl_table mq_sysctl_dir[] = { | |
1203 | { | |
1204 | .ctl_name = FS_MQUEUE, | |
1205 | .procname = "mqueue", | |
1206 | .mode = 0555, | |
1207 | .child = mq_sysctls, | |
1208 | }, | |
1209 | { .ctl_name = 0 } | |
1210 | }; | |
1211 | ||
1212 | static ctl_table mq_sysctl_root[] = { | |
1213 | { | |
1214 | .ctl_name = CTL_FS, | |
1215 | .procname = "fs", | |
1216 | .mode = 0555, | |
1217 | .child = mq_sysctl_dir, | |
1218 | }, | |
1219 | { .ctl_name = 0 } | |
1220 | }; | |
1221 | ||
1222 | static int __init init_mqueue_fs(void) | |
1223 | { | |
1224 | int error; | |
1225 | ||
1226 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", | |
1227 | sizeof(struct mqueue_inode_info), 0, | |
1228 | SLAB_HWCACHE_ALIGN, init_once, NULL); | |
1229 | if (mqueue_inode_cachep == NULL) | |
1230 | return -ENOMEM; | |
1231 | ||
1232 | /* ignore failues - they are not fatal */ | |
1233 | mq_sysctl_table = register_sysctl_table(mq_sysctl_root, 0); | |
1234 | ||
1235 | error = register_filesystem(&mqueue_fs_type); | |
1236 | if (error) | |
1237 | goto out_sysctl; | |
1238 | ||
1239 | if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) { | |
1240 | error = PTR_ERR(mqueue_mnt); | |
1241 | goto out_filesystem; | |
1242 | } | |
1243 | ||
1244 | /* internal initialization - not common for vfs */ | |
1245 | queues_count = 0; | |
1246 | spin_lock_init(&mq_lock); | |
1247 | ||
1248 | return 0; | |
1249 | ||
1250 | out_filesystem: | |
1251 | unregister_filesystem(&mqueue_fs_type); | |
1252 | out_sysctl: | |
1253 | if (mq_sysctl_table) | |
1254 | unregister_sysctl_table(mq_sysctl_table); | |
1255 | if (kmem_cache_destroy(mqueue_inode_cachep)) { | |
1256 | printk(KERN_INFO | |
1257 | "mqueue_inode_cache: not all structures were freed\n"); | |
1258 | } | |
1259 | return error; | |
1260 | } | |
1261 | ||
1262 | __initcall(init_mqueue_fs); |