Commit | Line | Data |
---|---|---|
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 | * | |
20ca73bc GW |
11 | * Audit: George Wilson (ltcgcw@us.ibm.com) |
12 | * | |
1da177e4 LT |
13 | * This file is released under the GPL. |
14 | */ | |
15 | ||
c59ede7b | 16 | #include <linux/capability.h> |
1da177e4 LT |
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> | |
20ca73bc | 29 | #include <linux/audit.h> |
7ed20e1a | 30 | #include <linux/signal.h> |
5f921ae9 IM |
31 | #include <linux/mutex.h> |
32 | ||
1da177e4 LT |
33 | #include <net/sock.h> |
34 | #include "util.h" | |
35 | ||
36 | #define MQUEUE_MAGIC 0x19800202 | |
37 | #define DIRENT_SIZE 20 | |
38 | #define FILENT_SIZE 80 | |
39 | ||
40 | #define SEND 0 | |
41 | #define RECV 1 | |
42 | ||
43 | #define STATE_NONE 0 | |
44 | #define STATE_PENDING 1 | |
45 | #define STATE_READY 2 | |
46 | ||
47 | /* used by sysctl */ | |
48 | #define FS_MQUEUE 1 | |
49 | #define CTL_QUEUESMAX 2 | |
50 | #define CTL_MSGMAX 3 | |
51 | #define CTL_MSGSIZEMAX 4 | |
52 | ||
53 | /* default values */ | |
54 | #define DFLT_QUEUESMAX 256 /* max number of message queues */ | |
55 | #define DFLT_MSGMAX 10 /* max number of messages in each queue */ | |
56 | #define HARD_MSGMAX (131072/sizeof(void*)) | |
57 | #define DFLT_MSGSIZEMAX 8192 /* max message size */ | |
58 | ||
1da177e4 LT |
59 | |
60 | struct ext_wait_queue { /* queue of sleeping tasks */ | |
61 | struct task_struct *task; | |
62 | struct list_head list; | |
63 | struct msg_msg *msg; /* ptr of loaded message */ | |
64 | int state; /* one of STATE_* values */ | |
65 | }; | |
66 | ||
67 | struct mqueue_inode_info { | |
68 | spinlock_t lock; | |
69 | struct inode vfs_inode; | |
70 | wait_queue_head_t wait_q; | |
71 | ||
72 | struct msg_msg **messages; | |
73 | struct mq_attr attr; | |
74 | ||
75 | struct sigevent notify; | |
76 | pid_t notify_owner; | |
338cec32 | 77 | struct user_struct *user; /* user who created, for accounting */ |
1da177e4 LT |
78 | struct sock *notify_sock; |
79 | struct sk_buff *notify_cookie; | |
80 | ||
81 | /* for tasks waiting for free space and messages, respectively */ | |
82 | struct ext_wait_queue e_wait_q[2]; | |
83 | ||
84 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ | |
85 | }; | |
86 | ||
87 | static struct inode_operations mqueue_dir_inode_operations; | |
88 | static struct file_operations mqueue_file_operations; | |
89 | static struct super_operations mqueue_super_ops; | |
90 | static void remove_notification(struct mqueue_inode_info *info); | |
91 | ||
92 | static spinlock_t mq_lock; | |
93 | static kmem_cache_t *mqueue_inode_cachep; | |
94 | static struct vfsmount *mqueue_mnt; | |
95 | ||
96 | static unsigned int queues_count; | |
97 | static unsigned int queues_max = DFLT_QUEUESMAX; | |
98 | static unsigned int msg_max = DFLT_MSGMAX; | |
99 | static unsigned int msgsize_max = DFLT_MSGSIZEMAX; | |
100 | ||
101 | static struct ctl_table_header * mq_sysctl_table; | |
102 | ||
103 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) | |
104 | { | |
105 | return container_of(inode, struct mqueue_inode_info, vfs_inode); | |
106 | } | |
107 | ||
108 | static struct inode *mqueue_get_inode(struct super_block *sb, int mode, | |
109 | struct mq_attr *attr) | |
110 | { | |
111 | struct inode *inode; | |
112 | ||
113 | inode = new_inode(sb); | |
114 | if (inode) { | |
115 | inode->i_mode = mode; | |
116 | inode->i_uid = current->fsuid; | |
117 | inode->i_gid = current->fsgid; | |
118 | inode->i_blksize = PAGE_CACHE_SIZE; | |
119 | inode->i_blocks = 0; | |
120 | inode->i_mtime = inode->i_ctime = inode->i_atime = | |
121 | CURRENT_TIME; | |
122 | ||
123 | if (S_ISREG(mode)) { | |
124 | struct mqueue_inode_info *info; | |
125 | struct task_struct *p = current; | |
126 | struct user_struct *u = p->user; | |
127 | unsigned long mq_bytes, mq_msg_tblsz; | |
128 | ||
129 | inode->i_fop = &mqueue_file_operations; | |
130 | inode->i_size = FILENT_SIZE; | |
131 | /* mqueue specific info */ | |
132 | info = MQUEUE_I(inode); | |
133 | spin_lock_init(&info->lock); | |
134 | init_waitqueue_head(&info->wait_q); | |
135 | INIT_LIST_HEAD(&info->e_wait_q[0].list); | |
136 | INIT_LIST_HEAD(&info->e_wait_q[1].list); | |
137 | info->messages = NULL; | |
138 | info->notify_owner = 0; | |
139 | info->qsize = 0; | |
140 | info->user = NULL; /* set when all is ok */ | |
141 | memset(&info->attr, 0, sizeof(info->attr)); | |
142 | info->attr.mq_maxmsg = DFLT_MSGMAX; | |
143 | info->attr.mq_msgsize = DFLT_MSGSIZEMAX; | |
144 | if (attr) { | |
145 | info->attr.mq_maxmsg = attr->mq_maxmsg; | |
146 | info->attr.mq_msgsize = attr->mq_msgsize; | |
147 | } | |
148 | mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *); | |
149 | mq_bytes = (mq_msg_tblsz + | |
150 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
151 | ||
152 | spin_lock(&mq_lock); | |
153 | if (u->mq_bytes + mq_bytes < u->mq_bytes || | |
154 | u->mq_bytes + mq_bytes > | |
155 | p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) { | |
156 | spin_unlock(&mq_lock); | |
157 | goto out_inode; | |
158 | } | |
159 | u->mq_bytes += mq_bytes; | |
160 | spin_unlock(&mq_lock); | |
161 | ||
162 | info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL); | |
163 | if (!info->messages) { | |
164 | spin_lock(&mq_lock); | |
165 | u->mq_bytes -= mq_bytes; | |
166 | spin_unlock(&mq_lock); | |
167 | goto out_inode; | |
168 | } | |
169 | /* all is ok */ | |
170 | info->user = get_uid(u); | |
171 | } else if (S_ISDIR(mode)) { | |
172 | inode->i_nlink++; | |
173 | /* Some things misbehave if size == 0 on a directory */ | |
174 | inode->i_size = 2 * DIRENT_SIZE; | |
175 | inode->i_op = &mqueue_dir_inode_operations; | |
176 | inode->i_fop = &simple_dir_operations; | |
177 | } | |
178 | } | |
179 | return inode; | |
180 | out_inode: | |
181 | make_bad_inode(inode); | |
182 | iput(inode); | |
183 | return NULL; | |
184 | } | |
185 | ||
186 | static int mqueue_fill_super(struct super_block *sb, void *data, int silent) | |
187 | { | |
188 | struct inode *inode; | |
189 | ||
190 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
191 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
192 | sb->s_magic = MQUEUE_MAGIC; | |
193 | sb->s_op = &mqueue_super_ops; | |
194 | ||
195 | inode = mqueue_get_inode(sb, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); | |
196 | if (!inode) | |
197 | return -ENOMEM; | |
198 | ||
199 | sb->s_root = d_alloc_root(inode); | |
200 | if (!sb->s_root) { | |
201 | iput(inode); | |
202 | return -ENOMEM; | |
203 | } | |
204 | ||
205 | return 0; | |
206 | } | |
207 | ||
454e2398 DH |
208 | static int mqueue_get_sb(struct file_system_type *fs_type, |
209 | int flags, const char *dev_name, | |
210 | void *data, struct vfsmount *mnt) | |
1da177e4 | 211 | { |
454e2398 | 212 | return get_sb_single(fs_type, flags, data, mqueue_fill_super, mnt); |
1da177e4 LT |
213 | } |
214 | ||
215 | static void init_once(void *foo, kmem_cache_t * cachep, unsigned long flags) | |
216 | { | |
217 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; | |
218 | ||
219 | if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) == | |
220 | SLAB_CTOR_CONSTRUCTOR) | |
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, SLAB_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 | inode->i_nlink--; | |
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_dentry->d_inode); | |
327 | char buffer[FILENT_SIZE]; | |
328 | size_t slen; | |
329 | loff_t o; | |
330 | ||
331 | if (!count) | |
332 | return 0; | |
333 | ||
334 | spin_lock(&info->lock); | |
335 | snprintf(buffer, sizeof(buffer), | |
336 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", | |
337 | info->qsize, | |
338 | info->notify_owner ? info->notify.sigev_notify : 0, | |
339 | (info->notify_owner && | |
340 | info->notify.sigev_notify == SIGEV_SIGNAL) ? | |
341 | info->notify.sigev_signo : 0, | |
342 | info->notify_owner); | |
343 | spin_unlock(&info->lock); | |
344 | buffer[sizeof(buffer)-1] = '\0'; | |
345 | slen = strlen(buffer)+1; | |
346 | ||
347 | o = *off; | |
348 | if (o > slen) | |
349 | return 0; | |
350 | ||
351 | if (o + count > slen) | |
352 | count = slen - o; | |
353 | ||
354 | if (copy_to_user(u_data, buffer + o, count)) | |
355 | return -EFAULT; | |
356 | ||
357 | *off = o + count; | |
358 | filp->f_dentry->d_inode->i_atime = filp->f_dentry->d_inode->i_ctime = CURRENT_TIME; | |
359 | return count; | |
360 | } | |
361 | ||
75e1fcc0 | 362 | static int mqueue_flush_file(struct file *filp, fl_owner_t id) |
1da177e4 LT |
363 | { |
364 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode); | |
365 | ||
366 | spin_lock(&info->lock); | |
367 | if (current->tgid == info->notify_owner) | |
368 | remove_notification(info); | |
369 | ||
370 | spin_unlock(&info->lock); | |
371 | return 0; | |
372 | } | |
373 | ||
374 | static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) | |
375 | { | |
376 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode); | |
377 | int retval = 0; | |
378 | ||
379 | poll_wait(filp, &info->wait_q, poll_tab); | |
380 | ||
381 | spin_lock(&info->lock); | |
382 | if (info->attr.mq_curmsgs) | |
383 | retval = POLLIN | POLLRDNORM; | |
384 | ||
385 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) | |
386 | retval |= POLLOUT | POLLWRNORM; | |
387 | spin_unlock(&info->lock); | |
388 | ||
389 | return retval; | |
390 | } | |
391 | ||
392 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ | |
393 | static void wq_add(struct mqueue_inode_info *info, int sr, | |
394 | struct ext_wait_queue *ewp) | |
395 | { | |
396 | struct ext_wait_queue *walk; | |
397 | ||
398 | ewp->task = current; | |
399 | ||
400 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { | |
401 | if (walk->task->static_prio <= current->static_prio) { | |
402 | list_add_tail(&ewp->list, &walk->list); | |
403 | return; | |
404 | } | |
405 | } | |
406 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); | |
407 | } | |
408 | ||
409 | /* | |
410 | * Puts current task to sleep. Caller must hold queue lock. After return | |
411 | * lock isn't held. | |
412 | * sr: SEND or RECV | |
413 | */ | |
414 | static int wq_sleep(struct mqueue_inode_info *info, int sr, | |
415 | long timeout, struct ext_wait_queue *ewp) | |
416 | { | |
417 | int retval; | |
418 | signed long time; | |
419 | ||
420 | wq_add(info, sr, ewp); | |
421 | ||
422 | for (;;) { | |
423 | set_current_state(TASK_INTERRUPTIBLE); | |
424 | ||
425 | spin_unlock(&info->lock); | |
426 | time = schedule_timeout(timeout); | |
427 | ||
428 | while (ewp->state == STATE_PENDING) | |
429 | cpu_relax(); | |
430 | ||
431 | if (ewp->state == STATE_READY) { | |
432 | retval = 0; | |
433 | goto out; | |
434 | } | |
435 | spin_lock(&info->lock); | |
436 | if (ewp->state == STATE_READY) { | |
437 | retval = 0; | |
438 | goto out_unlock; | |
439 | } | |
440 | if (signal_pending(current)) { | |
441 | retval = -ERESTARTSYS; | |
442 | break; | |
443 | } | |
444 | if (time == 0) { | |
445 | retval = -ETIMEDOUT; | |
446 | break; | |
447 | } | |
448 | } | |
449 | list_del(&ewp->list); | |
450 | out_unlock: | |
451 | spin_unlock(&info->lock); | |
452 | out: | |
453 | return retval; | |
454 | } | |
455 | ||
456 | /* | |
457 | * Returns waiting task that should be serviced first or NULL if none exists | |
458 | */ | |
459 | static struct ext_wait_queue *wq_get_first_waiter( | |
460 | struct mqueue_inode_info *info, int sr) | |
461 | { | |
462 | struct list_head *ptr; | |
463 | ||
464 | ptr = info->e_wait_q[sr].list.prev; | |
465 | if (ptr == &info->e_wait_q[sr].list) | |
466 | return NULL; | |
467 | return list_entry(ptr, struct ext_wait_queue, list); | |
468 | } | |
469 | ||
470 | /* Auxiliary functions to manipulate messages' list */ | |
471 | static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info) | |
472 | { | |
473 | int k; | |
474 | ||
475 | k = info->attr.mq_curmsgs - 1; | |
476 | while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) { | |
477 | info->messages[k + 1] = info->messages[k]; | |
478 | k--; | |
479 | } | |
480 | info->attr.mq_curmsgs++; | |
481 | info->qsize += ptr->m_ts; | |
482 | info->messages[k + 1] = ptr; | |
483 | } | |
484 | ||
485 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) | |
486 | { | |
487 | info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts; | |
488 | return info->messages[info->attr.mq_curmsgs]; | |
489 | } | |
490 | ||
491 | static inline void set_cookie(struct sk_buff *skb, char code) | |
492 | { | |
493 | ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; | |
494 | } | |
495 | ||
496 | /* | |
497 | * The next function is only to split too long sys_mq_timedsend | |
498 | */ | |
499 | static void __do_notify(struct mqueue_inode_info *info) | |
500 | { | |
501 | /* notification | |
502 | * invoked when there is registered process and there isn't process | |
503 | * waiting synchronously for message AND state of queue changed from | |
504 | * empty to not empty. Here we are sure that no one is waiting | |
505 | * synchronously. */ | |
506 | if (info->notify_owner && | |
507 | info->attr.mq_curmsgs == 1) { | |
508 | struct siginfo sig_i; | |
509 | switch (info->notify.sigev_notify) { | |
510 | case SIGEV_NONE: | |
511 | break; | |
512 | case SIGEV_SIGNAL: | |
513 | /* sends signal */ | |
514 | ||
515 | sig_i.si_signo = info->notify.sigev_signo; | |
516 | sig_i.si_errno = 0; | |
517 | sig_i.si_code = SI_MESGQ; | |
518 | sig_i.si_value = info->notify.sigev_value; | |
519 | sig_i.si_pid = current->tgid; | |
520 | sig_i.si_uid = current->uid; | |
521 | ||
522 | kill_proc_info(info->notify.sigev_signo, | |
523 | &sig_i, info->notify_owner); | |
524 | break; | |
525 | case SIGEV_THREAD: | |
526 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); | |
527 | netlink_sendskb(info->notify_sock, | |
528 | info->notify_cookie, 0); | |
529 | break; | |
530 | } | |
531 | /* after notification unregisters process */ | |
532 | info->notify_owner = 0; | |
533 | } | |
534 | wake_up(&info->wait_q); | |
535 | } | |
536 | ||
537 | static long prepare_timeout(const struct timespec __user *u_arg) | |
538 | { | |
539 | struct timespec ts, nowts; | |
540 | long timeout; | |
541 | ||
542 | if (u_arg) { | |
543 | if (unlikely(copy_from_user(&ts, u_arg, | |
544 | sizeof(struct timespec)))) | |
545 | return -EFAULT; | |
546 | ||
547 | if (unlikely(ts.tv_nsec < 0 || ts.tv_sec < 0 | |
548 | || ts.tv_nsec >= NSEC_PER_SEC)) | |
549 | return -EINVAL; | |
550 | nowts = CURRENT_TIME; | |
551 | /* first subtract as jiffies can't be too big */ | |
552 | ts.tv_sec -= nowts.tv_sec; | |
553 | if (ts.tv_nsec < nowts.tv_nsec) { | |
554 | ts.tv_nsec += NSEC_PER_SEC; | |
555 | ts.tv_sec--; | |
556 | } | |
557 | ts.tv_nsec -= nowts.tv_nsec; | |
558 | if (ts.tv_sec < 0) | |
559 | return 0; | |
560 | ||
561 | timeout = timespec_to_jiffies(&ts) + 1; | |
562 | } else | |
563 | return MAX_SCHEDULE_TIMEOUT; | |
564 | ||
565 | return timeout; | |
566 | } | |
567 | ||
568 | static void remove_notification(struct mqueue_inode_info *info) | |
569 | { | |
570 | if (info->notify_owner != 0 && | |
571 | info->notify.sigev_notify == SIGEV_THREAD) { | |
572 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); | |
573 | netlink_sendskb(info->notify_sock, info->notify_cookie, 0); | |
574 | } | |
575 | info->notify_owner = 0; | |
576 | } | |
577 | ||
578 | static int mq_attr_ok(struct mq_attr *attr) | |
579 | { | |
580 | if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) | |
581 | return 0; | |
582 | if (capable(CAP_SYS_RESOURCE)) { | |
583 | if (attr->mq_maxmsg > HARD_MSGMAX) | |
584 | return 0; | |
585 | } else { | |
586 | if (attr->mq_maxmsg > msg_max || | |
587 | attr->mq_msgsize > msgsize_max) | |
588 | return 0; | |
589 | } | |
590 | /* check for overflow */ | |
591 | if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) | |
592 | return 0; | |
593 | if ((unsigned long)(attr->mq_maxmsg * attr->mq_msgsize) + | |
594 | (attr->mq_maxmsg * sizeof (struct msg_msg *)) < | |
595 | (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize)) | |
596 | return 0; | |
597 | return 1; | |
598 | } | |
599 | ||
600 | /* | |
601 | * Invoked when creating a new queue via sys_mq_open | |
602 | */ | |
603 | static struct file *do_create(struct dentry *dir, struct dentry *dentry, | |
604 | int oflag, mode_t mode, struct mq_attr __user *u_attr) | |
605 | { | |
1da177e4 LT |
606 | struct mq_attr attr; |
607 | int ret; | |
608 | ||
7c7dce92 AV |
609 | if (u_attr) { |
610 | ret = -EFAULT; | |
1da177e4 | 611 | if (copy_from_user(&attr, u_attr, sizeof(attr))) |
7c7dce92 AV |
612 | goto out; |
613 | ret = -EINVAL; | |
1da177e4 | 614 | if (!mq_attr_ok(&attr)) |
7c7dce92 | 615 | goto out; |
1da177e4 LT |
616 | /* store for use during create */ |
617 | dentry->d_fsdata = &attr; | |
618 | } | |
619 | ||
59175839 | 620 | mode &= ~current->fs->umask; |
1da177e4 LT |
621 | ret = vfs_create(dir->d_inode, dentry, mode, NULL); |
622 | dentry->d_fsdata = NULL; | |
623 | if (ret) | |
7c7dce92 | 624 | goto out; |
1da177e4 | 625 | |
7c7dce92 | 626 | return dentry_open(dentry, mqueue_mnt, oflag); |
1da177e4 | 627 | |
7c7dce92 AV |
628 | out: |
629 | dput(dentry); | |
630 | mntput(mqueue_mnt); | |
631 | return ERR_PTR(ret); | |
1da177e4 LT |
632 | } |
633 | ||
634 | /* Opens existing queue */ | |
635 | static struct file *do_open(struct dentry *dentry, int oflag) | |
636 | { | |
637 | static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, | |
638 | MAY_READ | MAY_WRITE }; | |
1da177e4 | 639 | |
7c7dce92 AV |
640 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { |
641 | dput(dentry); | |
642 | mntput(mqueue_mnt); | |
1da177e4 | 643 | return ERR_PTR(-EINVAL); |
7c7dce92 | 644 | } |
1da177e4 | 645 | |
7c7dce92 AV |
646 | if (permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE], NULL)) { |
647 | dput(dentry); | |
648 | mntput(mqueue_mnt); | |
1da177e4 | 649 | return ERR_PTR(-EACCES); |
7c7dce92 | 650 | } |
1da177e4 | 651 | |
7c7dce92 | 652 | return dentry_open(dentry, mqueue_mnt, oflag); |
1da177e4 LT |
653 | } |
654 | ||
655 | asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode, | |
656 | struct mq_attr __user *u_attr) | |
657 | { | |
658 | struct dentry *dentry; | |
659 | struct file *filp; | |
660 | char *name; | |
661 | int fd, error; | |
662 | ||
20ca73bc GW |
663 | error = audit_mq_open(oflag, mode, u_attr); |
664 | if (error != 0) | |
665 | return error; | |
666 | ||
1da177e4 LT |
667 | if (IS_ERR(name = getname(u_name))) |
668 | return PTR_ERR(name); | |
669 | ||
670 | fd = get_unused_fd(); | |
671 | if (fd < 0) | |
672 | goto out_putname; | |
673 | ||
1b1dcc1b | 674 | mutex_lock(&mqueue_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
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 */ | |
7c7dce92 AV |
684 | error = -EEXIST; |
685 | if (oflag & O_EXCL) | |
686 | goto out; | |
687 | filp = do_open(dentry, oflag); | |
1da177e4 LT |
688 | } else { |
689 | filp = do_create(mqueue_mnt->mnt_root, dentry, | |
690 | oflag, mode, u_attr); | |
691 | } | |
7c7dce92 AV |
692 | } else { |
693 | error = -ENOENT; | |
694 | if (!dentry->d_inode) | |
695 | goto out; | |
696 | filp = do_open(dentry, oflag); | |
697 | } | |
1da177e4 LT |
698 | |
699 | if (IS_ERR(filp)) { | |
700 | error = PTR_ERR(filp); | |
701 | goto out_putfd; | |
702 | } | |
703 | ||
704 | set_close_on_exec(fd, 1); | |
705 | fd_install(fd, filp); | |
706 | goto out_upsem; | |
707 | ||
7c7dce92 AV |
708 | out: |
709 | dput(dentry); | |
1da177e4 | 710 | mntput(mqueue_mnt); |
7c7dce92 | 711 | out_putfd: |
1da177e4 LT |
712 | put_unused_fd(fd); |
713 | out_err: | |
714 | fd = error; | |
715 | out_upsem: | |
1b1dcc1b | 716 | mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
717 | out_putname: |
718 | putname(name); | |
719 | return fd; | |
720 | } | |
721 | ||
722 | asmlinkage long sys_mq_unlink(const char __user *u_name) | |
723 | { | |
724 | int err; | |
725 | char *name; | |
726 | struct dentry *dentry; | |
727 | struct inode *inode = NULL; | |
728 | ||
729 | name = getname(u_name); | |
730 | if (IS_ERR(name)) | |
731 | return PTR_ERR(name); | |
732 | ||
1b1dcc1b | 733 | mutex_lock(&mqueue_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
734 | dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name)); |
735 | if (IS_ERR(dentry)) { | |
736 | err = PTR_ERR(dentry); | |
737 | goto out_unlock; | |
738 | } | |
739 | ||
740 | if (!dentry->d_inode) { | |
741 | err = -ENOENT; | |
742 | goto out_err; | |
743 | } | |
744 | ||
745 | inode = dentry->d_inode; | |
746 | if (inode) | |
747 | atomic_inc(&inode->i_count); | |
748 | ||
749 | err = vfs_unlink(dentry->d_parent->d_inode, dentry); | |
750 | out_err: | |
751 | dput(dentry); | |
752 | ||
753 | out_unlock: | |
1b1dcc1b | 754 | mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
755 | putname(name); |
756 | if (inode) | |
757 | iput(inode); | |
758 | ||
759 | return err; | |
760 | } | |
761 | ||
762 | /* Pipelined send and receive functions. | |
763 | * | |
764 | * If a receiver finds no waiting message, then it registers itself in the | |
765 | * list of waiting receivers. A sender checks that list before adding the new | |
766 | * message into the message array. If there is a waiting receiver, then it | |
767 | * bypasses the message array and directly hands the message over to the | |
768 | * receiver. | |
769 | * The receiver accepts the message and returns without grabbing the queue | |
770 | * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers | |
771 | * are necessary. The same algorithm is used for sysv semaphores, see | |
7b7a317c | 772 | * ipc/sem.c for more details. |
1da177e4 LT |
773 | * |
774 | * The same algorithm is used for senders. | |
775 | */ | |
776 | ||
777 | /* pipelined_send() - send a message directly to the task waiting in | |
778 | * sys_mq_timedreceive() (without inserting message into a queue). | |
779 | */ | |
780 | static inline void pipelined_send(struct mqueue_inode_info *info, | |
781 | struct msg_msg *message, | |
782 | struct ext_wait_queue *receiver) | |
783 | { | |
784 | receiver->msg = message; | |
785 | list_del(&receiver->list); | |
786 | receiver->state = STATE_PENDING; | |
787 | wake_up_process(receiver->task); | |
d59dd462 | 788 | smp_wmb(); |
1da177e4 LT |
789 | receiver->state = STATE_READY; |
790 | } | |
791 | ||
792 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() | |
793 | * gets its message and put to the queue (we have one free place for sure). */ | |
794 | static inline void pipelined_receive(struct mqueue_inode_info *info) | |
795 | { | |
796 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); | |
797 | ||
798 | if (!sender) { | |
799 | /* for poll */ | |
800 | wake_up_interruptible(&info->wait_q); | |
801 | return; | |
802 | } | |
803 | msg_insert(sender->msg, info); | |
804 | list_del(&sender->list); | |
805 | sender->state = STATE_PENDING; | |
806 | wake_up_process(sender->task); | |
d59dd462 | 807 | smp_wmb(); |
1da177e4 LT |
808 | sender->state = STATE_READY; |
809 | } | |
810 | ||
811 | asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr, | |
812 | size_t msg_len, unsigned int msg_prio, | |
813 | const struct timespec __user *u_abs_timeout) | |
814 | { | |
815 | struct file *filp; | |
816 | struct inode *inode; | |
817 | struct ext_wait_queue wait; | |
818 | struct ext_wait_queue *receiver; | |
819 | struct msg_msg *msg_ptr; | |
820 | struct mqueue_inode_info *info; | |
821 | long timeout; | |
822 | int ret; | |
823 | ||
20ca73bc GW |
824 | ret = audit_mq_timedsend(mqdes, msg_len, msg_prio, u_abs_timeout); |
825 | if (ret != 0) | |
826 | return ret; | |
827 | ||
1da177e4 LT |
828 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) |
829 | return -EINVAL; | |
830 | ||
831 | timeout = prepare_timeout(u_abs_timeout); | |
832 | ||
833 | ret = -EBADF; | |
834 | filp = fget(mqdes); | |
835 | if (unlikely(!filp)) | |
836 | goto out; | |
837 | ||
838 | inode = filp->f_dentry->d_inode; | |
839 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
840 | goto out_fput; | |
841 | info = MQUEUE_I(inode); | |
842 | ||
843 | if (unlikely(!(filp->f_mode & FMODE_WRITE))) | |
844 | goto out_fput; | |
845 | ||
846 | if (unlikely(msg_len > info->attr.mq_msgsize)) { | |
847 | ret = -EMSGSIZE; | |
848 | goto out_fput; | |
849 | } | |
850 | ||
851 | /* First try to allocate memory, before doing anything with | |
852 | * existing queues. */ | |
853 | msg_ptr = load_msg(u_msg_ptr, msg_len); | |
854 | if (IS_ERR(msg_ptr)) { | |
855 | ret = PTR_ERR(msg_ptr); | |
856 | goto out_fput; | |
857 | } | |
858 | msg_ptr->m_ts = msg_len; | |
859 | msg_ptr->m_type = msg_prio; | |
860 | ||
861 | spin_lock(&info->lock); | |
862 | ||
863 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { | |
864 | if (filp->f_flags & O_NONBLOCK) { | |
865 | spin_unlock(&info->lock); | |
866 | ret = -EAGAIN; | |
867 | } else if (unlikely(timeout < 0)) { | |
868 | spin_unlock(&info->lock); | |
869 | ret = timeout; | |
870 | } else { | |
871 | wait.task = current; | |
872 | wait.msg = (void *) msg_ptr; | |
873 | wait.state = STATE_NONE; | |
874 | ret = wq_sleep(info, SEND, timeout, &wait); | |
875 | } | |
876 | if (ret < 0) | |
877 | free_msg(msg_ptr); | |
878 | } else { | |
879 | receiver = wq_get_first_waiter(info, RECV); | |
880 | if (receiver) { | |
881 | pipelined_send(info, msg_ptr, receiver); | |
882 | } else { | |
883 | /* adds message to the queue */ | |
884 | msg_insert(msg_ptr, info); | |
885 | __do_notify(info); | |
886 | } | |
887 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
888 | CURRENT_TIME; | |
889 | spin_unlock(&info->lock); | |
890 | ret = 0; | |
891 | } | |
892 | out_fput: | |
893 | fput(filp); | |
894 | out: | |
895 | return ret; | |
896 | } | |
897 | ||
898 | asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr, | |
899 | size_t msg_len, unsigned int __user *u_msg_prio, | |
900 | const struct timespec __user *u_abs_timeout) | |
901 | { | |
902 | long timeout; | |
903 | ssize_t ret; | |
904 | struct msg_msg *msg_ptr; | |
905 | struct file *filp; | |
906 | struct inode *inode; | |
907 | struct mqueue_inode_info *info; | |
908 | struct ext_wait_queue wait; | |
909 | ||
20ca73bc GW |
910 | ret = audit_mq_timedreceive(mqdes, msg_len, u_msg_prio, u_abs_timeout); |
911 | if (ret != 0) | |
912 | return ret; | |
913 | ||
1da177e4 LT |
914 | timeout = prepare_timeout(u_abs_timeout); |
915 | ||
916 | ret = -EBADF; | |
917 | filp = fget(mqdes); | |
918 | if (unlikely(!filp)) | |
919 | goto out; | |
920 | ||
921 | inode = filp->f_dentry->d_inode; | |
922 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
923 | goto out_fput; | |
924 | info = MQUEUE_I(inode); | |
925 | ||
926 | if (unlikely(!(filp->f_mode & FMODE_READ))) | |
927 | goto out_fput; | |
928 | ||
929 | /* checks if buffer is big enough */ | |
930 | if (unlikely(msg_len < info->attr.mq_msgsize)) { | |
931 | ret = -EMSGSIZE; | |
932 | goto out_fput; | |
933 | } | |
934 | ||
935 | spin_lock(&info->lock); | |
936 | if (info->attr.mq_curmsgs == 0) { | |
937 | if (filp->f_flags & O_NONBLOCK) { | |
938 | spin_unlock(&info->lock); | |
939 | ret = -EAGAIN; | |
940 | msg_ptr = NULL; | |
941 | } else if (unlikely(timeout < 0)) { | |
942 | spin_unlock(&info->lock); | |
943 | ret = timeout; | |
944 | msg_ptr = NULL; | |
945 | } else { | |
946 | wait.task = current; | |
947 | wait.state = STATE_NONE; | |
948 | ret = wq_sleep(info, RECV, timeout, &wait); | |
949 | msg_ptr = wait.msg; | |
950 | } | |
951 | } else { | |
952 | msg_ptr = msg_get(info); | |
953 | ||
954 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
955 | CURRENT_TIME; | |
956 | ||
957 | /* There is now free space in queue. */ | |
958 | pipelined_receive(info); | |
959 | spin_unlock(&info->lock); | |
960 | ret = 0; | |
961 | } | |
962 | if (ret == 0) { | |
963 | ret = msg_ptr->m_ts; | |
964 | ||
965 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || | |
966 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { | |
967 | ret = -EFAULT; | |
968 | } | |
969 | free_msg(msg_ptr); | |
970 | } | |
971 | out_fput: | |
972 | fput(filp); | |
973 | out: | |
974 | return ret; | |
975 | } | |
976 | ||
977 | /* | |
978 | * Notes: the case when user wants us to deregister (with NULL as pointer) | |
979 | * and he isn't currently owner of notification, will be silently discarded. | |
980 | * It isn't explicitly defined in the POSIX. | |
981 | */ | |
982 | asmlinkage long sys_mq_notify(mqd_t mqdes, | |
983 | const struct sigevent __user *u_notification) | |
984 | { | |
985 | int ret; | |
986 | struct file *filp; | |
987 | struct sock *sock; | |
988 | struct inode *inode; | |
989 | struct sigevent notification; | |
990 | struct mqueue_inode_info *info; | |
991 | struct sk_buff *nc; | |
992 | ||
20ca73bc GW |
993 | ret = audit_mq_notify(mqdes, u_notification); |
994 | if (ret != 0) | |
995 | return ret; | |
996 | ||
1da177e4 LT |
997 | nc = NULL; |
998 | sock = NULL; | |
999 | if (u_notification != NULL) { | |
1000 | if (copy_from_user(¬ification, u_notification, | |
1001 | sizeof(struct sigevent))) | |
1002 | return -EFAULT; | |
1003 | ||
1004 | if (unlikely(notification.sigev_notify != SIGEV_NONE && | |
1005 | notification.sigev_notify != SIGEV_SIGNAL && | |
1006 | notification.sigev_notify != SIGEV_THREAD)) | |
1007 | return -EINVAL; | |
1008 | if (notification.sigev_notify == SIGEV_SIGNAL && | |
7ed20e1a | 1009 | !valid_signal(notification.sigev_signo)) { |
1da177e4 LT |
1010 | return -EINVAL; |
1011 | } | |
1012 | if (notification.sigev_notify == SIGEV_THREAD) { | |
1013 | /* create the notify skb */ | |
1014 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); | |
1015 | ret = -ENOMEM; | |
1016 | if (!nc) | |
1017 | goto out; | |
1018 | ret = -EFAULT; | |
1019 | if (copy_from_user(nc->data, | |
1020 | notification.sigev_value.sival_ptr, | |
1021 | NOTIFY_COOKIE_LEN)) { | |
1022 | goto out; | |
1023 | } | |
1024 | ||
1025 | /* TODO: add a header? */ | |
1026 | skb_put(nc, NOTIFY_COOKIE_LEN); | |
1027 | /* and attach it to the socket */ | |
1028 | retry: | |
1029 | filp = fget(notification.sigev_signo); | |
1030 | ret = -EBADF; | |
1031 | if (!filp) | |
1032 | goto out; | |
1033 | sock = netlink_getsockbyfilp(filp); | |
1034 | fput(filp); | |
1035 | if (IS_ERR(sock)) { | |
1036 | ret = PTR_ERR(sock); | |
1037 | sock = NULL; | |
1038 | goto out; | |
1039 | } | |
1040 | ||
a70ea994 AK |
1041 | ret = netlink_attachskb(sock, nc, 0, |
1042 | MAX_SCHEDULE_TIMEOUT, NULL); | |
1da177e4 LT |
1043 | if (ret == 1) |
1044 | goto retry; | |
1045 | if (ret) { | |
1046 | sock = NULL; | |
1047 | nc = NULL; | |
1048 | goto out; | |
1049 | } | |
1050 | } | |
1051 | } | |
1052 | ||
1053 | ret = -EBADF; | |
1054 | filp = fget(mqdes); | |
1055 | if (!filp) | |
1056 | goto out; | |
1057 | ||
1058 | inode = filp->f_dentry->d_inode; | |
1059 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
1060 | goto out_fput; | |
1061 | info = MQUEUE_I(inode); | |
1062 | ||
1063 | ret = 0; | |
1064 | spin_lock(&info->lock); | |
1065 | if (u_notification == NULL) { | |
1066 | if (info->notify_owner == current->tgid) { | |
1067 | remove_notification(info); | |
1068 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1069 | } | |
1070 | } else if (info->notify_owner != 0) { | |
1071 | ret = -EBUSY; | |
1072 | } else { | |
1073 | switch (notification.sigev_notify) { | |
1074 | case SIGEV_NONE: | |
1075 | info->notify.sigev_notify = SIGEV_NONE; | |
1076 | break; | |
1077 | case SIGEV_THREAD: | |
1078 | info->notify_sock = sock; | |
1079 | info->notify_cookie = nc; | |
1080 | sock = NULL; | |
1081 | nc = NULL; | |
1082 | info->notify.sigev_notify = SIGEV_THREAD; | |
1083 | break; | |
1084 | case SIGEV_SIGNAL: | |
1085 | info->notify.sigev_signo = notification.sigev_signo; | |
1086 | info->notify.sigev_value = notification.sigev_value; | |
1087 | info->notify.sigev_notify = SIGEV_SIGNAL; | |
1088 | break; | |
1089 | } | |
1090 | info->notify_owner = current->tgid; | |
1091 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1092 | } | |
1093 | spin_unlock(&info->lock); | |
1094 | out_fput: | |
1095 | fput(filp); | |
1096 | out: | |
1097 | if (sock) { | |
1098 | netlink_detachskb(sock, nc); | |
1099 | } else if (nc) { | |
1100 | dev_kfree_skb(nc); | |
1101 | } | |
1102 | return ret; | |
1103 | } | |
1104 | ||
1105 | asmlinkage long sys_mq_getsetattr(mqd_t mqdes, | |
1106 | const struct mq_attr __user *u_mqstat, | |
1107 | struct mq_attr __user *u_omqstat) | |
1108 | { | |
1109 | int ret; | |
1110 | struct mq_attr mqstat, omqstat; | |
1111 | struct file *filp; | |
1112 | struct inode *inode; | |
1113 | struct mqueue_inode_info *info; | |
1114 | ||
1115 | if (u_mqstat != NULL) { | |
1116 | if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) | |
1117 | return -EFAULT; | |
1118 | if (mqstat.mq_flags & (~O_NONBLOCK)) | |
1119 | return -EINVAL; | |
1120 | } | |
1121 | ||
1122 | ret = -EBADF; | |
1123 | filp = fget(mqdes); | |
1124 | if (!filp) | |
1125 | goto out; | |
1126 | ||
1127 | inode = filp->f_dentry->d_inode; | |
1128 | if (unlikely(filp->f_op != &mqueue_file_operations)) | |
1129 | goto out_fput; | |
1130 | info = MQUEUE_I(inode); | |
1131 | ||
1132 | spin_lock(&info->lock); | |
1133 | ||
1134 | omqstat = info->attr; | |
1135 | omqstat.mq_flags = filp->f_flags & O_NONBLOCK; | |
1136 | if (u_mqstat) { | |
20ca73bc GW |
1137 | ret = audit_mq_getsetattr(mqdes, &mqstat); |
1138 | if (ret != 0) | |
1139 | goto out; | |
1da177e4 LT |
1140 | if (mqstat.mq_flags & O_NONBLOCK) |
1141 | filp->f_flags |= O_NONBLOCK; | |
1142 | else | |
1143 | filp->f_flags &= ~O_NONBLOCK; | |
1144 | ||
1145 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1146 | } | |
1147 | ||
1148 | spin_unlock(&info->lock); | |
1149 | ||
1150 | ret = 0; | |
1151 | if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, | |
1152 | sizeof(struct mq_attr))) | |
1153 | ret = -EFAULT; | |
1154 | ||
1155 | out_fput: | |
1156 | fput(filp); | |
1157 | out: | |
1158 | return ret; | |
1159 | } | |
1160 | ||
1161 | static struct inode_operations mqueue_dir_inode_operations = { | |
1162 | .lookup = simple_lookup, | |
1163 | .create = mqueue_create, | |
1164 | .unlink = mqueue_unlink, | |
1165 | }; | |
1166 | ||
1167 | static struct file_operations mqueue_file_operations = { | |
1168 | .flush = mqueue_flush_file, | |
1169 | .poll = mqueue_poll_file, | |
1170 | .read = mqueue_read_file, | |
1171 | }; | |
1172 | ||
1173 | static struct super_operations mqueue_super_ops = { | |
1174 | .alloc_inode = mqueue_alloc_inode, | |
1175 | .destroy_inode = mqueue_destroy_inode, | |
1176 | .statfs = simple_statfs, | |
1177 | .delete_inode = mqueue_delete_inode, | |
1178 | .drop_inode = generic_delete_inode, | |
1179 | }; | |
1180 | ||
1181 | static struct file_system_type mqueue_fs_type = { | |
1182 | .name = "mqueue", | |
1183 | .get_sb = mqueue_get_sb, | |
1184 | .kill_sb = kill_litter_super, | |
1185 | }; | |
1186 | ||
1187 | static int msg_max_limit_min = DFLT_MSGMAX; | |
1188 | static int msg_max_limit_max = HARD_MSGMAX; | |
1189 | ||
1190 | static int msg_maxsize_limit_min = DFLT_MSGSIZEMAX; | |
1191 | static int msg_maxsize_limit_max = INT_MAX; | |
1192 | ||
1193 | static ctl_table mq_sysctls[] = { | |
1194 | { | |
1195 | .ctl_name = CTL_QUEUESMAX, | |
1196 | .procname = "queues_max", | |
1197 | .data = &queues_max, | |
1198 | .maxlen = sizeof(int), | |
1199 | .mode = 0644, | |
1200 | .proc_handler = &proc_dointvec, | |
1201 | }, | |
1202 | { | |
1203 | .ctl_name = CTL_MSGMAX, | |
1204 | .procname = "msg_max", | |
1205 | .data = &msg_max, | |
1206 | .maxlen = sizeof(int), | |
1207 | .mode = 0644, | |
1208 | .proc_handler = &proc_dointvec_minmax, | |
1209 | .extra1 = &msg_max_limit_min, | |
1210 | .extra2 = &msg_max_limit_max, | |
1211 | }, | |
1212 | { | |
1213 | .ctl_name = CTL_MSGSIZEMAX, | |
1214 | .procname = "msgsize_max", | |
1215 | .data = &msgsize_max, | |
1216 | .maxlen = sizeof(int), | |
1217 | .mode = 0644, | |
1218 | .proc_handler = &proc_dointvec_minmax, | |
1219 | .extra1 = &msg_maxsize_limit_min, | |
1220 | .extra2 = &msg_maxsize_limit_max, | |
1221 | }, | |
1222 | { .ctl_name = 0 } | |
1223 | }; | |
1224 | ||
1225 | static ctl_table mq_sysctl_dir[] = { | |
1226 | { | |
1227 | .ctl_name = FS_MQUEUE, | |
1228 | .procname = "mqueue", | |
1229 | .mode = 0555, | |
1230 | .child = mq_sysctls, | |
1231 | }, | |
1232 | { .ctl_name = 0 } | |
1233 | }; | |
1234 | ||
1235 | static ctl_table mq_sysctl_root[] = { | |
1236 | { | |
1237 | .ctl_name = CTL_FS, | |
1238 | .procname = "fs", | |
1239 | .mode = 0555, | |
1240 | .child = mq_sysctl_dir, | |
1241 | }, | |
1242 | { .ctl_name = 0 } | |
1243 | }; | |
1244 | ||
1245 | static int __init init_mqueue_fs(void) | |
1246 | { | |
1247 | int error; | |
1248 | ||
1249 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", | |
1250 | sizeof(struct mqueue_inode_info), 0, | |
1251 | SLAB_HWCACHE_ALIGN, init_once, NULL); | |
1252 | if (mqueue_inode_cachep == NULL) | |
1253 | return -ENOMEM; | |
1254 | ||
1255 | /* ignore failues - they are not fatal */ | |
1256 | mq_sysctl_table = register_sysctl_table(mq_sysctl_root, 0); | |
1257 | ||
1258 | error = register_filesystem(&mqueue_fs_type); | |
1259 | if (error) | |
1260 | goto out_sysctl; | |
1261 | ||
1262 | if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) { | |
1263 | error = PTR_ERR(mqueue_mnt); | |
1264 | goto out_filesystem; | |
1265 | } | |
1266 | ||
1267 | /* internal initialization - not common for vfs */ | |
1268 | queues_count = 0; | |
1269 | spin_lock_init(&mq_lock); | |
1270 | ||
1271 | return 0; | |
1272 | ||
1273 | out_filesystem: | |
1274 | unregister_filesystem(&mqueue_fs_type); | |
1275 | out_sysctl: | |
1276 | if (mq_sysctl_table) | |
1277 | unregister_sysctl_table(mq_sysctl_table); | |
1278 | if (kmem_cache_destroy(mqueue_inode_cachep)) { | |
1279 | printk(KERN_INFO | |
1280 | "mqueue_inode_cache: not all structures were freed\n"); | |
1281 | } | |
1282 | return error; | |
1283 | } | |
1284 | ||
1285 | __initcall(init_mqueue_fs); |