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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 | #include <linux/ipc_namespace.h> | |
35 | #include <linux/slab.h> | |
36 | ||
37 | #include <net/sock.h> | |
38 | #include "util.h" | |
39 | ||
40 | #define MQUEUE_MAGIC 0x19800202 | |
41 | #define DIRENT_SIZE 20 | |
42 | #define FILENT_SIZE 80 | |
43 | ||
44 | #define SEND 0 | |
45 | #define RECV 1 | |
46 | ||
47 | #define STATE_NONE 0 | |
48 | #define STATE_PENDING 1 | |
49 | #define STATE_READY 2 | |
50 | ||
51 | struct ext_wait_queue { /* queue of sleeping tasks */ | |
52 | struct task_struct *task; | |
53 | struct list_head list; | |
54 | struct msg_msg *msg; /* ptr of loaded message */ | |
55 | int state; /* one of STATE_* values */ | |
56 | }; | |
57 | ||
58 | struct mqueue_inode_info { | |
59 | spinlock_t lock; | |
60 | struct inode vfs_inode; | |
61 | wait_queue_head_t wait_q; | |
62 | ||
63 | struct msg_msg **messages; | |
64 | struct mq_attr attr; | |
65 | ||
66 | struct sigevent notify; | |
67 | struct pid* notify_owner; | |
68 | struct user_struct *user; /* user who created, for accounting */ | |
69 | struct sock *notify_sock; | |
70 | struct sk_buff *notify_cookie; | |
71 | ||
72 | /* for tasks waiting for free space and messages, respectively */ | |
73 | struct ext_wait_queue e_wait_q[2]; | |
74 | ||
75 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ | |
76 | }; | |
77 | ||
78 | static const struct inode_operations mqueue_dir_inode_operations; | |
79 | static const struct file_operations mqueue_file_operations; | |
80 | static const struct super_operations mqueue_super_ops; | |
81 | static void remove_notification(struct mqueue_inode_info *info); | |
82 | ||
83 | static struct kmem_cache *mqueue_inode_cachep; | |
84 | ||
85 | static struct ctl_table_header * mq_sysctl_table; | |
86 | ||
87 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) | |
88 | { | |
89 | return container_of(inode, struct mqueue_inode_info, vfs_inode); | |
90 | } | |
91 | ||
92 | /* | |
93 | * This routine should be called with the mq_lock held. | |
94 | */ | |
95 | static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode) | |
96 | { | |
97 | return get_ipc_ns(inode->i_sb->s_fs_info); | |
98 | } | |
99 | ||
100 | static struct ipc_namespace *get_ns_from_inode(struct inode *inode) | |
101 | { | |
102 | struct ipc_namespace *ns; | |
103 | ||
104 | spin_lock(&mq_lock); | |
105 | ns = __get_ns_from_inode(inode); | |
106 | spin_unlock(&mq_lock); | |
107 | return ns; | |
108 | } | |
109 | ||
110 | static struct inode *mqueue_get_inode(struct super_block *sb, | |
111 | struct ipc_namespace *ipc_ns, int mode, | |
112 | struct mq_attr *attr) | |
113 | { | |
114 | struct user_struct *u = current_user(); | |
115 | struct inode *inode; | |
116 | ||
117 | inode = new_inode(sb); | |
118 | if (inode) { | |
119 | inode->i_ino = get_next_ino(); | |
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->notify_owner = NULL; | |
140 | info->qsize = 0; | |
141 | info->user = NULL; /* set when all is ok */ | |
142 | memset(&info->attr, 0, sizeof(info->attr)); | |
143 | info->attr.mq_maxmsg = ipc_ns->mq_msg_max; | |
144 | info->attr.mq_msgsize = ipc_ns->mq_msgsize_max; | |
145 | if (attr) { | |
146 | info->attr.mq_maxmsg = attr->mq_maxmsg; | |
147 | info->attr.mq_msgsize = attr->mq_msgsize; | |
148 | } | |
149 | mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *); | |
150 | info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL); | |
151 | if (!info->messages) | |
152 | goto out_inode; | |
153 | ||
154 | mq_bytes = (mq_msg_tblsz + | |
155 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
156 | ||
157 | spin_lock(&mq_lock); | |
158 | if (u->mq_bytes + mq_bytes < u->mq_bytes || | |
159 | u->mq_bytes + mq_bytes > | |
160 | task_rlimit(p, RLIMIT_MSGQUEUE)) { | |
161 | spin_unlock(&mq_lock); | |
162 | /* mqueue_evict_inode() releases info->messages */ | |
163 | goto out_inode; | |
164 | } | |
165 | u->mq_bytes += mq_bytes; | |
166 | spin_unlock(&mq_lock); | |
167 | ||
168 | /* all is ok */ | |
169 | info->user = get_uid(u); | |
170 | } else if (S_ISDIR(mode)) { | |
171 | inc_nlink(inode); | |
172 | /* Some things misbehave if size == 0 on a directory */ | |
173 | inode->i_size = 2 * DIRENT_SIZE; | |
174 | inode->i_op = &mqueue_dir_inode_operations; | |
175 | inode->i_fop = &simple_dir_operations; | |
176 | } | |
177 | } | |
178 | return inode; | |
179 | out_inode: | |
180 | iput(inode); | |
181 | return NULL; | |
182 | } | |
183 | ||
184 | static int mqueue_fill_super(struct super_block *sb, void *data, int silent) | |
185 | { | |
186 | struct inode *inode; | |
187 | struct ipc_namespace *ns = data; | |
188 | int error; | |
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, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, | |
196 | NULL); | |
197 | if (!inode) { | |
198 | error = -ENOMEM; | |
199 | goto out; | |
200 | } | |
201 | ||
202 | sb->s_root = d_alloc_root(inode); | |
203 | if (!sb->s_root) { | |
204 | iput(inode); | |
205 | error = -ENOMEM; | |
206 | goto out; | |
207 | } | |
208 | error = 0; | |
209 | ||
210 | out: | |
211 | return error; | |
212 | } | |
213 | ||
214 | static struct dentry *mqueue_mount(struct file_system_type *fs_type, | |
215 | int flags, const char *dev_name, | |
216 | void *data) | |
217 | { | |
218 | if (!(flags & MS_KERNMOUNT)) | |
219 | data = current->nsproxy->ipc_ns; | |
220 | return mount_ns(fs_type, flags, data, mqueue_fill_super); | |
221 | } | |
222 | ||
223 | static void init_once(void *foo) | |
224 | { | |
225 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; | |
226 | ||
227 | inode_init_once(&p->vfs_inode); | |
228 | } | |
229 | ||
230 | static struct inode *mqueue_alloc_inode(struct super_block *sb) | |
231 | { | |
232 | struct mqueue_inode_info *ei; | |
233 | ||
234 | ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL); | |
235 | if (!ei) | |
236 | return NULL; | |
237 | return &ei->vfs_inode; | |
238 | } | |
239 | ||
240 | static void mqueue_destroy_inode(struct inode *inode) | |
241 | { | |
242 | kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); | |
243 | } | |
244 | ||
245 | static void mqueue_evict_inode(struct inode *inode) | |
246 | { | |
247 | struct mqueue_inode_info *info; | |
248 | struct user_struct *user; | |
249 | unsigned long mq_bytes; | |
250 | int i; | |
251 | struct ipc_namespace *ipc_ns; | |
252 | ||
253 | end_writeback(inode); | |
254 | ||
255 | if (S_ISDIR(inode->i_mode)) | |
256 | return; | |
257 | ||
258 | ipc_ns = get_ns_from_inode(inode); | |
259 | info = MQUEUE_I(inode); | |
260 | spin_lock(&info->lock); | |
261 | for (i = 0; i < info->attr.mq_curmsgs; i++) | |
262 | free_msg(info->messages[i]); | |
263 | kfree(info->messages); | |
264 | spin_unlock(&info->lock); | |
265 | ||
266 | /* Total amount of bytes accounted for the mqueue */ | |
267 | mq_bytes = info->attr.mq_maxmsg * (sizeof(struct msg_msg *) | |
268 | + info->attr.mq_msgsize); | |
269 | user = info->user; | |
270 | if (user) { | |
271 | spin_lock(&mq_lock); | |
272 | user->mq_bytes -= mq_bytes; | |
273 | /* | |
274 | * get_ns_from_inode() ensures that the | |
275 | * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns | |
276 | * to which we now hold a reference, or it is NULL. | |
277 | * We can't put it here under mq_lock, though. | |
278 | */ | |
279 | if (ipc_ns) | |
280 | ipc_ns->mq_queues_count--; | |
281 | spin_unlock(&mq_lock); | |
282 | free_uid(user); | |
283 | } | |
284 | if (ipc_ns) | |
285 | put_ipc_ns(ipc_ns); | |
286 | } | |
287 | ||
288 | static int mqueue_create(struct inode *dir, struct dentry *dentry, | |
289 | int mode, struct nameidata *nd) | |
290 | { | |
291 | struct inode *inode; | |
292 | struct mq_attr *attr = dentry->d_fsdata; | |
293 | int error; | |
294 | struct ipc_namespace *ipc_ns; | |
295 | ||
296 | spin_lock(&mq_lock); | |
297 | ipc_ns = __get_ns_from_inode(dir); | |
298 | if (!ipc_ns) { | |
299 | error = -EACCES; | |
300 | goto out_unlock; | |
301 | } | |
302 | if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max && | |
303 | !capable(CAP_SYS_RESOURCE)) { | |
304 | error = -ENOSPC; | |
305 | goto out_unlock; | |
306 | } | |
307 | ipc_ns->mq_queues_count++; | |
308 | spin_unlock(&mq_lock); | |
309 | ||
310 | inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr); | |
311 | if (!inode) { | |
312 | error = -ENOMEM; | |
313 | spin_lock(&mq_lock); | |
314 | ipc_ns->mq_queues_count--; | |
315 | goto out_unlock; | |
316 | } | |
317 | ||
318 | put_ipc_ns(ipc_ns); | |
319 | dir->i_size += DIRENT_SIZE; | |
320 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
321 | ||
322 | d_instantiate(dentry, inode); | |
323 | dget(dentry); | |
324 | return 0; | |
325 | out_unlock: | |
326 | spin_unlock(&mq_lock); | |
327 | if (ipc_ns) | |
328 | put_ipc_ns(ipc_ns); | |
329 | return error; | |
330 | } | |
331 | ||
332 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) | |
333 | { | |
334 | struct inode *inode = dentry->d_inode; | |
335 | ||
336 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
337 | dir->i_size -= DIRENT_SIZE; | |
338 | drop_nlink(inode); | |
339 | dput(dentry); | |
340 | return 0; | |
341 | } | |
342 | ||
343 | /* | |
344 | * This is routine for system read from queue file. | |
345 | * To avoid mess with doing here some sort of mq_receive we allow | |
346 | * to read only queue size & notification info (the only values | |
347 | * that are interesting from user point of view and aren't accessible | |
348 | * through std routines) | |
349 | */ | |
350 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, | |
351 | size_t count, loff_t *off) | |
352 | { | |
353 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); | |
354 | char buffer[FILENT_SIZE]; | |
355 | ssize_t ret; | |
356 | ||
357 | spin_lock(&info->lock); | |
358 | snprintf(buffer, sizeof(buffer), | |
359 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", | |
360 | info->qsize, | |
361 | info->notify_owner ? info->notify.sigev_notify : 0, | |
362 | (info->notify_owner && | |
363 | info->notify.sigev_notify == SIGEV_SIGNAL) ? | |
364 | info->notify.sigev_signo : 0, | |
365 | pid_vnr(info->notify_owner)); | |
366 | spin_unlock(&info->lock); | |
367 | buffer[sizeof(buffer)-1] = '\0'; | |
368 | ||
369 | ret = simple_read_from_buffer(u_data, count, off, buffer, | |
370 | strlen(buffer)); | |
371 | if (ret <= 0) | |
372 | return ret; | |
373 | ||
374 | filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME; | |
375 | return ret; | |
376 | } | |
377 | ||
378 | static int mqueue_flush_file(struct file *filp, fl_owner_t id) | |
379 | { | |
380 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); | |
381 | ||
382 | spin_lock(&info->lock); | |
383 | if (task_tgid(current) == info->notify_owner) | |
384 | remove_notification(info); | |
385 | ||
386 | spin_unlock(&info->lock); | |
387 | return 0; | |
388 | } | |
389 | ||
390 | static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) | |
391 | { | |
392 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); | |
393 | int retval = 0; | |
394 | ||
395 | poll_wait(filp, &info->wait_q, poll_tab); | |
396 | ||
397 | spin_lock(&info->lock); | |
398 | if (info->attr.mq_curmsgs) | |
399 | retval = POLLIN | POLLRDNORM; | |
400 | ||
401 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) | |
402 | retval |= POLLOUT | POLLWRNORM; | |
403 | spin_unlock(&info->lock); | |
404 | ||
405 | return retval; | |
406 | } | |
407 | ||
408 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ | |
409 | static void wq_add(struct mqueue_inode_info *info, int sr, | |
410 | struct ext_wait_queue *ewp) | |
411 | { | |
412 | struct ext_wait_queue *walk; | |
413 | ||
414 | ewp->task = current; | |
415 | ||
416 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { | |
417 | if (walk->task->static_prio <= current->static_prio) { | |
418 | list_add_tail(&ewp->list, &walk->list); | |
419 | return; | |
420 | } | |
421 | } | |
422 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); | |
423 | } | |
424 | ||
425 | /* | |
426 | * Puts current task to sleep. Caller must hold queue lock. After return | |
427 | * lock isn't held. | |
428 | * sr: SEND or RECV | |
429 | */ | |
430 | static int wq_sleep(struct mqueue_inode_info *info, int sr, | |
431 | ktime_t *timeout, struct ext_wait_queue *ewp) | |
432 | { | |
433 | int retval; | |
434 | signed long time; | |
435 | ||
436 | wq_add(info, sr, ewp); | |
437 | ||
438 | for (;;) { | |
439 | set_current_state(TASK_INTERRUPTIBLE); | |
440 | ||
441 | spin_unlock(&info->lock); | |
442 | time = schedule_hrtimeout_range_clock(timeout, | |
443 | HRTIMER_MODE_ABS, 0, CLOCK_REALTIME); | |
444 | ||
445 | while (ewp->state == STATE_PENDING) | |
446 | cpu_relax(); | |
447 | ||
448 | if (ewp->state == STATE_READY) { | |
449 | retval = 0; | |
450 | goto out; | |
451 | } | |
452 | spin_lock(&info->lock); | |
453 | if (ewp->state == STATE_READY) { | |
454 | retval = 0; | |
455 | goto out_unlock; | |
456 | } | |
457 | if (signal_pending(current)) { | |
458 | retval = -ERESTARTSYS; | |
459 | break; | |
460 | } | |
461 | if (time == 0) { | |
462 | retval = -ETIMEDOUT; | |
463 | break; | |
464 | } | |
465 | } | |
466 | list_del(&ewp->list); | |
467 | out_unlock: | |
468 | spin_unlock(&info->lock); | |
469 | out: | |
470 | return retval; | |
471 | } | |
472 | ||
473 | /* | |
474 | * Returns waiting task that should be serviced first or NULL if none exists | |
475 | */ | |
476 | static struct ext_wait_queue *wq_get_first_waiter( | |
477 | struct mqueue_inode_info *info, int sr) | |
478 | { | |
479 | struct list_head *ptr; | |
480 | ||
481 | ptr = info->e_wait_q[sr].list.prev; | |
482 | if (ptr == &info->e_wait_q[sr].list) | |
483 | return NULL; | |
484 | return list_entry(ptr, struct ext_wait_queue, list); | |
485 | } | |
486 | ||
487 | /* Auxiliary functions to manipulate messages' list */ | |
488 | static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info) | |
489 | { | |
490 | int k; | |
491 | ||
492 | k = info->attr.mq_curmsgs - 1; | |
493 | while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) { | |
494 | info->messages[k + 1] = info->messages[k]; | |
495 | k--; | |
496 | } | |
497 | info->attr.mq_curmsgs++; | |
498 | info->qsize += ptr->m_ts; | |
499 | info->messages[k + 1] = ptr; | |
500 | } | |
501 | ||
502 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) | |
503 | { | |
504 | info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts; | |
505 | return info->messages[info->attr.mq_curmsgs]; | |
506 | } | |
507 | ||
508 | static inline void set_cookie(struct sk_buff *skb, char code) | |
509 | { | |
510 | ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; | |
511 | } | |
512 | ||
513 | /* | |
514 | * The next function is only to split too long sys_mq_timedsend | |
515 | */ | |
516 | static void __do_notify(struct mqueue_inode_info *info) | |
517 | { | |
518 | /* notification | |
519 | * invoked when there is registered process and there isn't process | |
520 | * waiting synchronously for message AND state of queue changed from | |
521 | * empty to not empty. Here we are sure that no one is waiting | |
522 | * synchronously. */ | |
523 | if (info->notify_owner && | |
524 | info->attr.mq_curmsgs == 1) { | |
525 | struct siginfo sig_i; | |
526 | switch (info->notify.sigev_notify) { | |
527 | case SIGEV_NONE: | |
528 | break; | |
529 | case SIGEV_SIGNAL: | |
530 | /* sends signal */ | |
531 | ||
532 | sig_i.si_signo = info->notify.sigev_signo; | |
533 | sig_i.si_errno = 0; | |
534 | sig_i.si_code = SI_MESGQ; | |
535 | sig_i.si_value = info->notify.sigev_value; | |
536 | sig_i.si_pid = task_tgid_nr_ns(current, | |
537 | ns_of_pid(info->notify_owner)); | |
538 | sig_i.si_uid = current_uid(); | |
539 | ||
540 | kill_pid_info(info->notify.sigev_signo, | |
541 | &sig_i, info->notify_owner); | |
542 | break; | |
543 | case SIGEV_THREAD: | |
544 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); | |
545 | netlink_sendskb(info->notify_sock, info->notify_cookie); | |
546 | break; | |
547 | } | |
548 | /* after notification unregisters process */ | |
549 | put_pid(info->notify_owner); | |
550 | info->notify_owner = NULL; | |
551 | } | |
552 | wake_up(&info->wait_q); | |
553 | } | |
554 | ||
555 | static int prepare_timeout(const struct timespec __user *u_abs_timeout, | |
556 | ktime_t *expires, struct timespec *ts) | |
557 | { | |
558 | if (copy_from_user(ts, u_abs_timeout, sizeof(struct timespec))) | |
559 | return -EFAULT; | |
560 | if (!timespec_valid(ts)) | |
561 | return -EINVAL; | |
562 | ||
563 | *expires = timespec_to_ktime(*ts); | |
564 | return 0; | |
565 | } | |
566 | ||
567 | static void remove_notification(struct mqueue_inode_info *info) | |
568 | { | |
569 | if (info->notify_owner != NULL && | |
570 | info->notify.sigev_notify == SIGEV_THREAD) { | |
571 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); | |
572 | netlink_sendskb(info->notify_sock, info->notify_cookie); | |
573 | } | |
574 | put_pid(info->notify_owner); | |
575 | info->notify_owner = NULL; | |
576 | } | |
577 | ||
578 | static int mq_attr_ok(struct ipc_namespace *ipc_ns, 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 > ipc_ns->mq_msg_max || | |
587 | attr->mq_msgsize > ipc_ns->mq_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 | + 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 ipc_namespace *ipc_ns, struct dentry *dir, | |
604 | struct dentry *dentry, int oflag, mode_t mode, | |
605 | struct mq_attr *attr) | |
606 | { | |
607 | const struct cred *cred = current_cred(); | |
608 | struct file *result; | |
609 | int ret; | |
610 | ||
611 | if (attr) { | |
612 | if (!mq_attr_ok(ipc_ns, attr)) { | |
613 | ret = -EINVAL; | |
614 | goto out; | |
615 | } | |
616 | /* store for use during create */ | |
617 | dentry->d_fsdata = attr; | |
618 | } | |
619 | ||
620 | mode &= ~current_umask(); | |
621 | ret = mnt_want_write(ipc_ns->mq_mnt); | |
622 | if (ret) | |
623 | goto out; | |
624 | ret = vfs_create(dir->d_inode, dentry, mode, NULL); | |
625 | dentry->d_fsdata = NULL; | |
626 | if (ret) | |
627 | goto out_drop_write; | |
628 | ||
629 | result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); | |
630 | /* | |
631 | * dentry_open() took a persistent mnt_want_write(), | |
632 | * so we can now drop this one. | |
633 | */ | |
634 | mnt_drop_write(ipc_ns->mq_mnt); | |
635 | return result; | |
636 | ||
637 | out_drop_write: | |
638 | mnt_drop_write(ipc_ns->mq_mnt); | |
639 | out: | |
640 | dput(dentry); | |
641 | mntput(ipc_ns->mq_mnt); | |
642 | return ERR_PTR(ret); | |
643 | } | |
644 | ||
645 | /* Opens existing queue */ | |
646 | static struct file *do_open(struct ipc_namespace *ipc_ns, | |
647 | struct dentry *dentry, int oflag) | |
648 | { | |
649 | int ret; | |
650 | const struct cred *cred = current_cred(); | |
651 | ||
652 | static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, | |
653 | MAY_READ | MAY_WRITE }; | |
654 | ||
655 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { | |
656 | ret = -EINVAL; | |
657 | goto err; | |
658 | } | |
659 | ||
660 | if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) { | |
661 | ret = -EACCES; | |
662 | goto err; | |
663 | } | |
664 | ||
665 | return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); | |
666 | ||
667 | err: | |
668 | dput(dentry); | |
669 | mntput(ipc_ns->mq_mnt); | |
670 | return ERR_PTR(ret); | |
671 | } | |
672 | ||
673 | SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode, | |
674 | struct mq_attr __user *, u_attr) | |
675 | { | |
676 | struct dentry *dentry; | |
677 | struct file *filp; | |
678 | char *name; | |
679 | struct mq_attr attr; | |
680 | int fd, error; | |
681 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; | |
682 | ||
683 | if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) | |
684 | return -EFAULT; | |
685 | ||
686 | audit_mq_open(oflag, mode, u_attr ? &attr : NULL); | |
687 | ||
688 | if (IS_ERR(name = getname(u_name))) | |
689 | return PTR_ERR(name); | |
690 | ||
691 | fd = get_unused_fd_flags(O_CLOEXEC); | |
692 | if (fd < 0) | |
693 | goto out_putname; | |
694 | ||
695 | mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); | |
696 | dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); | |
697 | if (IS_ERR(dentry)) { | |
698 | error = PTR_ERR(dentry); | |
699 | goto out_putfd; | |
700 | } | |
701 | mntget(ipc_ns->mq_mnt); | |
702 | ||
703 | if (oflag & O_CREAT) { | |
704 | if (dentry->d_inode) { /* entry already exists */ | |
705 | audit_inode(name, dentry); | |
706 | if (oflag & O_EXCL) { | |
707 | error = -EEXIST; | |
708 | goto out; | |
709 | } | |
710 | filp = do_open(ipc_ns, dentry, oflag); | |
711 | } else { | |
712 | filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root, | |
713 | dentry, oflag, mode, | |
714 | u_attr ? &attr : NULL); | |
715 | } | |
716 | } else { | |
717 | if (!dentry->d_inode) { | |
718 | error = -ENOENT; | |
719 | goto out; | |
720 | } | |
721 | audit_inode(name, dentry); | |
722 | filp = do_open(ipc_ns, dentry, oflag); | |
723 | } | |
724 | ||
725 | if (IS_ERR(filp)) { | |
726 | error = PTR_ERR(filp); | |
727 | goto out_putfd; | |
728 | } | |
729 | ||
730 | fd_install(fd, filp); | |
731 | goto out_upsem; | |
732 | ||
733 | out: | |
734 | dput(dentry); | |
735 | mntput(ipc_ns->mq_mnt); | |
736 | out_putfd: | |
737 | put_unused_fd(fd); | |
738 | fd = error; | |
739 | out_upsem: | |
740 | mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); | |
741 | out_putname: | |
742 | putname(name); | |
743 | return fd; | |
744 | } | |
745 | ||
746 | SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) | |
747 | { | |
748 | int err; | |
749 | char *name; | |
750 | struct dentry *dentry; | |
751 | struct inode *inode = NULL; | |
752 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; | |
753 | ||
754 | name = getname(u_name); | |
755 | if (IS_ERR(name)) | |
756 | return PTR_ERR(name); | |
757 | ||
758 | mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex, | |
759 | I_MUTEX_PARENT); | |
760 | dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); | |
761 | if (IS_ERR(dentry)) { | |
762 | err = PTR_ERR(dentry); | |
763 | goto out_unlock; | |
764 | } | |
765 | ||
766 | if (!dentry->d_inode) { | |
767 | err = -ENOENT; | |
768 | goto out_err; | |
769 | } | |
770 | ||
771 | inode = dentry->d_inode; | |
772 | if (inode) | |
773 | ihold(inode); | |
774 | err = mnt_want_write(ipc_ns->mq_mnt); | |
775 | if (err) | |
776 | goto out_err; | |
777 | err = vfs_unlink(dentry->d_parent->d_inode, dentry); | |
778 | mnt_drop_write(ipc_ns->mq_mnt); | |
779 | out_err: | |
780 | dput(dentry); | |
781 | ||
782 | out_unlock: | |
783 | mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); | |
784 | putname(name); | |
785 | if (inode) | |
786 | iput(inode); | |
787 | ||
788 | return err; | |
789 | } | |
790 | ||
791 | /* Pipelined send and receive functions. | |
792 | * | |
793 | * If a receiver finds no waiting message, then it registers itself in the | |
794 | * list of waiting receivers. A sender checks that list before adding the new | |
795 | * message into the message array. If there is a waiting receiver, then it | |
796 | * bypasses the message array and directly hands the message over to the | |
797 | * receiver. | |
798 | * The receiver accepts the message and returns without grabbing the queue | |
799 | * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers | |
800 | * are necessary. The same algorithm is used for sysv semaphores, see | |
801 | * ipc/sem.c for more details. | |
802 | * | |
803 | * The same algorithm is used for senders. | |
804 | */ | |
805 | ||
806 | /* pipelined_send() - send a message directly to the task waiting in | |
807 | * sys_mq_timedreceive() (without inserting message into a queue). | |
808 | */ | |
809 | static inline void pipelined_send(struct mqueue_inode_info *info, | |
810 | struct msg_msg *message, | |
811 | struct ext_wait_queue *receiver) | |
812 | { | |
813 | receiver->msg = message; | |
814 | list_del(&receiver->list); | |
815 | receiver->state = STATE_PENDING; | |
816 | wake_up_process(receiver->task); | |
817 | smp_wmb(); | |
818 | receiver->state = STATE_READY; | |
819 | } | |
820 | ||
821 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() | |
822 | * gets its message and put to the queue (we have one free place for sure). */ | |
823 | static inline void pipelined_receive(struct mqueue_inode_info *info) | |
824 | { | |
825 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); | |
826 | ||
827 | if (!sender) { | |
828 | /* for poll */ | |
829 | wake_up_interruptible(&info->wait_q); | |
830 | return; | |
831 | } | |
832 | msg_insert(sender->msg, info); | |
833 | list_del(&sender->list); | |
834 | sender->state = STATE_PENDING; | |
835 | wake_up_process(sender->task); | |
836 | smp_wmb(); | |
837 | sender->state = STATE_READY; | |
838 | } | |
839 | ||
840 | SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr, | |
841 | size_t, msg_len, unsigned int, msg_prio, | |
842 | const struct timespec __user *, u_abs_timeout) | |
843 | { | |
844 | struct file *filp; | |
845 | struct inode *inode; | |
846 | struct ext_wait_queue wait; | |
847 | struct ext_wait_queue *receiver; | |
848 | struct msg_msg *msg_ptr; | |
849 | struct mqueue_inode_info *info; | |
850 | ktime_t expires, *timeout = NULL; | |
851 | struct timespec ts; | |
852 | int ret; | |
853 | ||
854 | if (u_abs_timeout) { | |
855 | int res = prepare_timeout(u_abs_timeout, &expires, &ts); | |
856 | if (res) | |
857 | return res; | |
858 | timeout = &expires; | |
859 | } | |
860 | ||
861 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) | |
862 | return -EINVAL; | |
863 | ||
864 | audit_mq_sendrecv(mqdes, msg_len, msg_prio, timeout ? &ts : NULL); | |
865 | ||
866 | filp = fget(mqdes); | |
867 | if (unlikely(!filp)) { | |
868 | ret = -EBADF; | |
869 | goto out; | |
870 | } | |
871 | ||
872 | inode = filp->f_path.dentry->d_inode; | |
873 | if (unlikely(filp->f_op != &mqueue_file_operations)) { | |
874 | ret = -EBADF; | |
875 | goto out_fput; | |
876 | } | |
877 | info = MQUEUE_I(inode); | |
878 | audit_inode(NULL, filp->f_path.dentry); | |
879 | ||
880 | if (unlikely(!(filp->f_mode & FMODE_WRITE))) { | |
881 | ret = -EBADF; | |
882 | goto out_fput; | |
883 | } | |
884 | ||
885 | if (unlikely(msg_len > info->attr.mq_msgsize)) { | |
886 | ret = -EMSGSIZE; | |
887 | goto out_fput; | |
888 | } | |
889 | ||
890 | /* First try to allocate memory, before doing anything with | |
891 | * existing queues. */ | |
892 | msg_ptr = load_msg(u_msg_ptr, msg_len); | |
893 | if (IS_ERR(msg_ptr)) { | |
894 | ret = PTR_ERR(msg_ptr); | |
895 | goto out_fput; | |
896 | } | |
897 | msg_ptr->m_ts = msg_len; | |
898 | msg_ptr->m_type = msg_prio; | |
899 | ||
900 | spin_lock(&info->lock); | |
901 | ||
902 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { | |
903 | if (filp->f_flags & O_NONBLOCK) { | |
904 | spin_unlock(&info->lock); | |
905 | ret = -EAGAIN; | |
906 | } else { | |
907 | wait.task = current; | |
908 | wait.msg = (void *) msg_ptr; | |
909 | wait.state = STATE_NONE; | |
910 | ret = wq_sleep(info, SEND, timeout, &wait); | |
911 | } | |
912 | if (ret < 0) | |
913 | free_msg(msg_ptr); | |
914 | } else { | |
915 | receiver = wq_get_first_waiter(info, RECV); | |
916 | if (receiver) { | |
917 | pipelined_send(info, msg_ptr, receiver); | |
918 | } else { | |
919 | /* adds message to the queue */ | |
920 | msg_insert(msg_ptr, info); | |
921 | __do_notify(info); | |
922 | } | |
923 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
924 | CURRENT_TIME; | |
925 | spin_unlock(&info->lock); | |
926 | ret = 0; | |
927 | } | |
928 | out_fput: | |
929 | fput(filp); | |
930 | out: | |
931 | return ret; | |
932 | } | |
933 | ||
934 | SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr, | |
935 | size_t, msg_len, unsigned int __user *, u_msg_prio, | |
936 | const struct timespec __user *, u_abs_timeout) | |
937 | { | |
938 | ssize_t ret; | |
939 | struct msg_msg *msg_ptr; | |
940 | struct file *filp; | |
941 | struct inode *inode; | |
942 | struct mqueue_inode_info *info; | |
943 | struct ext_wait_queue wait; | |
944 | ktime_t expires, *timeout = NULL; | |
945 | struct timespec ts; | |
946 | ||
947 | if (u_abs_timeout) { | |
948 | int res = prepare_timeout(u_abs_timeout, &expires, &ts); | |
949 | if (res) | |
950 | return res; | |
951 | timeout = &expires; | |
952 | } | |
953 | ||
954 | audit_mq_sendrecv(mqdes, msg_len, 0, timeout ? &ts : NULL); | |
955 | ||
956 | filp = fget(mqdes); | |
957 | if (unlikely(!filp)) { | |
958 | ret = -EBADF; | |
959 | goto out; | |
960 | } | |
961 | ||
962 | inode = filp->f_path.dentry->d_inode; | |
963 | if (unlikely(filp->f_op != &mqueue_file_operations)) { | |
964 | ret = -EBADF; | |
965 | goto out_fput; | |
966 | } | |
967 | info = MQUEUE_I(inode); | |
968 | audit_inode(NULL, filp->f_path.dentry); | |
969 | ||
970 | if (unlikely(!(filp->f_mode & FMODE_READ))) { | |
971 | ret = -EBADF; | |
972 | goto out_fput; | |
973 | } | |
974 | ||
975 | /* checks if buffer is big enough */ | |
976 | if (unlikely(msg_len < info->attr.mq_msgsize)) { | |
977 | ret = -EMSGSIZE; | |
978 | goto out_fput; | |
979 | } | |
980 | ||
981 | spin_lock(&info->lock); | |
982 | if (info->attr.mq_curmsgs == 0) { | |
983 | if (filp->f_flags & O_NONBLOCK) { | |
984 | spin_unlock(&info->lock); | |
985 | ret = -EAGAIN; | |
986 | } else { | |
987 | wait.task = current; | |
988 | wait.state = STATE_NONE; | |
989 | ret = wq_sleep(info, RECV, timeout, &wait); | |
990 | msg_ptr = wait.msg; | |
991 | } | |
992 | } else { | |
993 | msg_ptr = msg_get(info); | |
994 | ||
995 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
996 | CURRENT_TIME; | |
997 | ||
998 | /* There is now free space in queue. */ | |
999 | pipelined_receive(info); | |
1000 | spin_unlock(&info->lock); | |
1001 | ret = 0; | |
1002 | } | |
1003 | if (ret == 0) { | |
1004 | ret = msg_ptr->m_ts; | |
1005 | ||
1006 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || | |
1007 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { | |
1008 | ret = -EFAULT; | |
1009 | } | |
1010 | free_msg(msg_ptr); | |
1011 | } | |
1012 | out_fput: | |
1013 | fput(filp); | |
1014 | out: | |
1015 | return ret; | |
1016 | } | |
1017 | ||
1018 | /* | |
1019 | * Notes: the case when user wants us to deregister (with NULL as pointer) | |
1020 | * and he isn't currently owner of notification, will be silently discarded. | |
1021 | * It isn't explicitly defined in the POSIX. | |
1022 | */ | |
1023 | SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, | |
1024 | const struct sigevent __user *, u_notification) | |
1025 | { | |
1026 | int ret; | |
1027 | struct file *filp; | |
1028 | struct sock *sock; | |
1029 | struct inode *inode; | |
1030 | struct sigevent notification; | |
1031 | struct mqueue_inode_info *info; | |
1032 | struct sk_buff *nc; | |
1033 | ||
1034 | if (u_notification) { | |
1035 | if (copy_from_user(¬ification, u_notification, | |
1036 | sizeof(struct sigevent))) | |
1037 | return -EFAULT; | |
1038 | } | |
1039 | ||
1040 | audit_mq_notify(mqdes, u_notification ? ¬ification : NULL); | |
1041 | ||
1042 | nc = NULL; | |
1043 | sock = NULL; | |
1044 | if (u_notification != NULL) { | |
1045 | if (unlikely(notification.sigev_notify != SIGEV_NONE && | |
1046 | notification.sigev_notify != SIGEV_SIGNAL && | |
1047 | notification.sigev_notify != SIGEV_THREAD)) | |
1048 | return -EINVAL; | |
1049 | if (notification.sigev_notify == SIGEV_SIGNAL && | |
1050 | !valid_signal(notification.sigev_signo)) { | |
1051 | return -EINVAL; | |
1052 | } | |
1053 | if (notification.sigev_notify == SIGEV_THREAD) { | |
1054 | long timeo; | |
1055 | ||
1056 | /* create the notify skb */ | |
1057 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); | |
1058 | if (!nc) { | |
1059 | ret = -ENOMEM; | |
1060 | goto out; | |
1061 | } | |
1062 | if (copy_from_user(nc->data, | |
1063 | notification.sigev_value.sival_ptr, | |
1064 | NOTIFY_COOKIE_LEN)) { | |
1065 | ret = -EFAULT; | |
1066 | goto out; | |
1067 | } | |
1068 | ||
1069 | /* TODO: add a header? */ | |
1070 | skb_put(nc, NOTIFY_COOKIE_LEN); | |
1071 | /* and attach it to the socket */ | |
1072 | retry: | |
1073 | filp = fget(notification.sigev_signo); | |
1074 | if (!filp) { | |
1075 | ret = -EBADF; | |
1076 | goto out; | |
1077 | } | |
1078 | sock = netlink_getsockbyfilp(filp); | |
1079 | fput(filp); | |
1080 | if (IS_ERR(sock)) { | |
1081 | ret = PTR_ERR(sock); | |
1082 | sock = NULL; | |
1083 | goto out; | |
1084 | } | |
1085 | ||
1086 | timeo = MAX_SCHEDULE_TIMEOUT; | |
1087 | ret = netlink_attachskb(sock, nc, &timeo, NULL); | |
1088 | if (ret == 1) | |
1089 | goto retry; | |
1090 | if (ret) { | |
1091 | sock = NULL; | |
1092 | nc = NULL; | |
1093 | goto out; | |
1094 | } | |
1095 | } | |
1096 | } | |
1097 | ||
1098 | filp = fget(mqdes); | |
1099 | if (!filp) { | |
1100 | ret = -EBADF; | |
1101 | goto out; | |
1102 | } | |
1103 | ||
1104 | inode = filp->f_path.dentry->d_inode; | |
1105 | if (unlikely(filp->f_op != &mqueue_file_operations)) { | |
1106 | ret = -EBADF; | |
1107 | goto out_fput; | |
1108 | } | |
1109 | info = MQUEUE_I(inode); | |
1110 | ||
1111 | ret = 0; | |
1112 | spin_lock(&info->lock); | |
1113 | if (u_notification == NULL) { | |
1114 | if (info->notify_owner == task_tgid(current)) { | |
1115 | remove_notification(info); | |
1116 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1117 | } | |
1118 | } else if (info->notify_owner != NULL) { | |
1119 | ret = -EBUSY; | |
1120 | } else { | |
1121 | switch (notification.sigev_notify) { | |
1122 | case SIGEV_NONE: | |
1123 | info->notify.sigev_notify = SIGEV_NONE; | |
1124 | break; | |
1125 | case SIGEV_THREAD: | |
1126 | info->notify_sock = sock; | |
1127 | info->notify_cookie = nc; | |
1128 | sock = NULL; | |
1129 | nc = NULL; | |
1130 | info->notify.sigev_notify = SIGEV_THREAD; | |
1131 | break; | |
1132 | case SIGEV_SIGNAL: | |
1133 | info->notify.sigev_signo = notification.sigev_signo; | |
1134 | info->notify.sigev_value = notification.sigev_value; | |
1135 | info->notify.sigev_notify = SIGEV_SIGNAL; | |
1136 | break; | |
1137 | } | |
1138 | ||
1139 | info->notify_owner = get_pid(task_tgid(current)); | |
1140 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1141 | } | |
1142 | spin_unlock(&info->lock); | |
1143 | out_fput: | |
1144 | fput(filp); | |
1145 | out: | |
1146 | if (sock) { | |
1147 | netlink_detachskb(sock, nc); | |
1148 | } else if (nc) { | |
1149 | dev_kfree_skb(nc); | |
1150 | } | |
1151 | return ret; | |
1152 | } | |
1153 | ||
1154 | SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, | |
1155 | const struct mq_attr __user *, u_mqstat, | |
1156 | struct mq_attr __user *, u_omqstat) | |
1157 | { | |
1158 | int ret; | |
1159 | struct mq_attr mqstat, omqstat; | |
1160 | struct file *filp; | |
1161 | struct inode *inode; | |
1162 | struct mqueue_inode_info *info; | |
1163 | ||
1164 | if (u_mqstat != NULL) { | |
1165 | if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) | |
1166 | return -EFAULT; | |
1167 | if (mqstat.mq_flags & (~O_NONBLOCK)) | |
1168 | return -EINVAL; | |
1169 | } | |
1170 | ||
1171 | filp = fget(mqdes); | |
1172 | if (!filp) { | |
1173 | ret = -EBADF; | |
1174 | goto out; | |
1175 | } | |
1176 | ||
1177 | inode = filp->f_path.dentry->d_inode; | |
1178 | if (unlikely(filp->f_op != &mqueue_file_operations)) { | |
1179 | ret = -EBADF; | |
1180 | goto out_fput; | |
1181 | } | |
1182 | info = MQUEUE_I(inode); | |
1183 | ||
1184 | spin_lock(&info->lock); | |
1185 | ||
1186 | omqstat = info->attr; | |
1187 | omqstat.mq_flags = filp->f_flags & O_NONBLOCK; | |
1188 | if (u_mqstat) { | |
1189 | audit_mq_getsetattr(mqdes, &mqstat); | |
1190 | spin_lock(&filp->f_lock); | |
1191 | if (mqstat.mq_flags & O_NONBLOCK) | |
1192 | filp->f_flags |= O_NONBLOCK; | |
1193 | else | |
1194 | filp->f_flags &= ~O_NONBLOCK; | |
1195 | spin_unlock(&filp->f_lock); | |
1196 | ||
1197 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1198 | } | |
1199 | ||
1200 | spin_unlock(&info->lock); | |
1201 | ||
1202 | ret = 0; | |
1203 | if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, | |
1204 | sizeof(struct mq_attr))) | |
1205 | ret = -EFAULT; | |
1206 | ||
1207 | out_fput: | |
1208 | fput(filp); | |
1209 | out: | |
1210 | return ret; | |
1211 | } | |
1212 | ||
1213 | static const struct inode_operations mqueue_dir_inode_operations = { | |
1214 | .lookup = simple_lookup, | |
1215 | .create = mqueue_create, | |
1216 | .unlink = mqueue_unlink, | |
1217 | }; | |
1218 | ||
1219 | static const struct file_operations mqueue_file_operations = { | |
1220 | .flush = mqueue_flush_file, | |
1221 | .poll = mqueue_poll_file, | |
1222 | .read = mqueue_read_file, | |
1223 | .llseek = default_llseek, | |
1224 | }; | |
1225 | ||
1226 | static const struct super_operations mqueue_super_ops = { | |
1227 | .alloc_inode = mqueue_alloc_inode, | |
1228 | .destroy_inode = mqueue_destroy_inode, | |
1229 | .evict_inode = mqueue_evict_inode, | |
1230 | .statfs = simple_statfs, | |
1231 | }; | |
1232 | ||
1233 | static struct file_system_type mqueue_fs_type = { | |
1234 | .name = "mqueue", | |
1235 | .mount = mqueue_mount, | |
1236 | .kill_sb = kill_litter_super, | |
1237 | }; | |
1238 | ||
1239 | int mq_init_ns(struct ipc_namespace *ns) | |
1240 | { | |
1241 | ns->mq_queues_count = 0; | |
1242 | ns->mq_queues_max = DFLT_QUEUESMAX; | |
1243 | ns->mq_msg_max = DFLT_MSGMAX; | |
1244 | ns->mq_msgsize_max = DFLT_MSGSIZEMAX; | |
1245 | ||
1246 | ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns); | |
1247 | if (IS_ERR(ns->mq_mnt)) { | |
1248 | int err = PTR_ERR(ns->mq_mnt); | |
1249 | ns->mq_mnt = NULL; | |
1250 | return err; | |
1251 | } | |
1252 | return 0; | |
1253 | } | |
1254 | ||
1255 | void mq_clear_sbinfo(struct ipc_namespace *ns) | |
1256 | { | |
1257 | ns->mq_mnt->mnt_sb->s_fs_info = NULL; | |
1258 | } | |
1259 | ||
1260 | void mq_put_mnt(struct ipc_namespace *ns) | |
1261 | { | |
1262 | mntput(ns->mq_mnt); | |
1263 | } | |
1264 | ||
1265 | static int __init init_mqueue_fs(void) | |
1266 | { | |
1267 | int error; | |
1268 | ||
1269 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", | |
1270 | sizeof(struct mqueue_inode_info), 0, | |
1271 | SLAB_HWCACHE_ALIGN, init_once); | |
1272 | if (mqueue_inode_cachep == NULL) | |
1273 | return -ENOMEM; | |
1274 | ||
1275 | /* ignore failures - they are not fatal */ | |
1276 | mq_sysctl_table = mq_register_sysctl_table(); | |
1277 | ||
1278 | error = register_filesystem(&mqueue_fs_type); | |
1279 | if (error) | |
1280 | goto out_sysctl; | |
1281 | ||
1282 | spin_lock_init(&mq_lock); | |
1283 | ||
1284 | init_ipc_ns.mq_mnt = kern_mount_data(&mqueue_fs_type, &init_ipc_ns); | |
1285 | if (IS_ERR(init_ipc_ns.mq_mnt)) { | |
1286 | error = PTR_ERR(init_ipc_ns.mq_mnt); | |
1287 | goto out_filesystem; | |
1288 | } | |
1289 | ||
1290 | return 0; | |
1291 | ||
1292 | out_filesystem: | |
1293 | unregister_filesystem(&mqueue_fs_type); | |
1294 | out_sysctl: | |
1295 | if (mq_sysctl_table) | |
1296 | unregister_sysctl_table(mq_sysctl_table); | |
1297 | kmem_cache_destroy(mqueue_inode_cachep); | |
1298 | return error; | |
1299 | } | |
1300 | ||
1301 | __initcall(init_mqueue_fs); |