blob: bfa274ba9ed40267201bee1f6fc45c4d5a5f213b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * POSIX message queues filesystem for Linux.
3 *
4 * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl)
Michal Wronskif66e9282006-10-03 23:23:27 +02005 * Michal Wronski (michal.wronski@gmail.com)
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
7 * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com)
8 * Lockless receive & send, fd based notify:
9 * Manfred Spraul (manfred@colorfullife.com)
10 *
George C. Wilson20ca73b2006-05-24 16:09:55 -050011 * Audit: George Wilson (ltcgcw@us.ibm.com)
12 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * This file is released under the GPL.
14 */
15
Randy.Dunlapc59ede72006-01-11 12:17:46 -080016#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#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>
George C. Wilson20ca73b2006-05-24 16:09:55 -050029#include <linux/audit.h>
Jesper Juhl7ed20e12005-05-01 08:59:14 -070030#include <linux/signal.h>
Ingo Molnar5f921ae2006-03-26 01:37:17 -080031#include <linux/mutex.h>
Pavel Emelyanovb4888932007-10-18 23:40:14 -070032#include <linux/nsproxy.h>
33#include <linux/pid.h>
Ingo Molnar5f921ae2006-03-26 01:37:17 -080034
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <net/sock.h>
36#include "util.h"
37
38#define MQUEUE_MAGIC 0x19800202
39#define DIRENT_SIZE 20
40#define FILENT_SIZE 80
41
42#define SEND 0
43#define RECV 1
44
45#define STATE_NONE 0
46#define STATE_PENDING 1
47#define STATE_READY 2
48
Linus Torvalds1da177e2005-04-16 15:20:36 -070049/* default values */
50#define DFLT_QUEUESMAX 256 /* max number of message queues */
51#define DFLT_MSGMAX 10 /* max number of messages in each queue */
52#define HARD_MSGMAX (131072/sizeof(void*))
53#define DFLT_MSGSIZEMAX 8192 /* max message size */
54
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
56struct 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
63struct 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;
Cedric Le Goatera03fcb72006-10-02 02:17:26 -070072 struct pid* notify_owner;
Adrian Bunk338cec32005-09-10 00:26:54 -070073 struct user_struct *user; /* user who created, for accounting */
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 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
Arjan van de Ven92e1d5b2007-02-12 00:55:39 -080083static const struct inode_operations mqueue_dir_inode_operations;
Arjan van de Ven9a321442007-02-12 00:55:35 -080084static const struct file_operations mqueue_file_operations;
Linus Torvalds1da177e2005-04-16 15:20:36 -070085static struct super_operations mqueue_super_ops;
86static void remove_notification(struct mqueue_inode_info *info);
87
88static spinlock_t mq_lock;
Christoph Lametere18b8902006-12-06 20:33:20 -080089static struct kmem_cache *mqueue_inode_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090static struct vfsmount *mqueue_mnt;
91
92static unsigned int queues_count;
93static unsigned int queues_max = DFLT_QUEUESMAX;
94static unsigned int msg_max = DFLT_MSGMAX;
95static unsigned int msgsize_max = DFLT_MSGSIZEMAX;
96
97static struct ctl_table_header * mq_sysctl_table;
98
99static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
100{
101 return container_of(inode, struct mqueue_inode_info, vfs_inode);
102}
103
104static 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 inode->i_blocks = 0;
115 inode->i_mtime = inode->i_ctime = inode->i_atime =
116 CURRENT_TIME;
117
118 if (S_ISREG(mode)) {
119 struct mqueue_inode_info *info;
120 struct task_struct *p = current;
121 struct user_struct *u = p->user;
122 unsigned long mq_bytes, mq_msg_tblsz;
123
124 inode->i_fop = &mqueue_file_operations;
125 inode->i_size = FILENT_SIZE;
126 /* mqueue specific info */
127 info = MQUEUE_I(inode);
128 spin_lock_init(&info->lock);
129 init_waitqueue_head(&info->wait_q);
130 INIT_LIST_HEAD(&info->e_wait_q[0].list);
131 INIT_LIST_HEAD(&info->e_wait_q[1].list);
132 info->messages = NULL;
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700133 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 info->qsize = 0;
135 info->user = NULL; /* set when all is ok */
136 memset(&info->attr, 0, sizeof(info->attr));
137 info->attr.mq_maxmsg = DFLT_MSGMAX;
138 info->attr.mq_msgsize = DFLT_MSGSIZEMAX;
139 if (attr) {
140 info->attr.mq_maxmsg = attr->mq_maxmsg;
141 info->attr.mq_msgsize = attr->mq_msgsize;
142 }
143 mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
144 mq_bytes = (mq_msg_tblsz +
145 (info->attr.mq_maxmsg * info->attr.mq_msgsize));
146
147 spin_lock(&mq_lock);
148 if (u->mq_bytes + mq_bytes < u->mq_bytes ||
149 u->mq_bytes + mq_bytes >
150 p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) {
151 spin_unlock(&mq_lock);
152 goto out_inode;
153 }
154 u->mq_bytes += mq_bytes;
155 spin_unlock(&mq_lock);
156
157 info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
158 if (!info->messages) {
159 spin_lock(&mq_lock);
160 u->mq_bytes -= mq_bytes;
161 spin_unlock(&mq_lock);
162 goto out_inode;
163 }
164 /* all is ok */
165 info->user = get_uid(u);
166 } else if (S_ISDIR(mode)) {
Dave Hansend8c76e62006-09-30 23:29:04 -0700167 inc_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 /* Some things misbehave if size == 0 on a directory */
169 inode->i_size = 2 * DIRENT_SIZE;
170 inode->i_op = &mqueue_dir_inode_operations;
171 inode->i_fop = &simple_dir_operations;
172 }
173 }
174 return inode;
175out_inode:
176 make_bad_inode(inode);
177 iput(inode);
178 return NULL;
179}
180
181static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
182{
183 struct inode *inode;
184
185 sb->s_blocksize = PAGE_CACHE_SIZE;
186 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
187 sb->s_magic = MQUEUE_MAGIC;
188 sb->s_op = &mqueue_super_ops;
189
190 inode = mqueue_get_inode(sb, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL);
191 if (!inode)
192 return -ENOMEM;
193
194 sb->s_root = d_alloc_root(inode);
195 if (!sb->s_root) {
196 iput(inode);
197 return -ENOMEM;
198 }
199
200 return 0;
201}
202
David Howells454e2392006-06-23 02:02:57 -0700203static int mqueue_get_sb(struct file_system_type *fs_type,
204 int flags, const char *dev_name,
205 void *data, struct vfsmount *mnt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206{
David Howells454e2392006-06-23 02:02:57 -0700207 return get_sb_single(fs_type, flags, data, mqueue_fill_super, mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208}
209
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -0700210static void init_once(struct kmem_cache *cachep, void *foo)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211{
212 struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
213
Christoph Lametera35afb82007-05-16 22:10:57 -0700214 inode_init_once(&p->vfs_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215}
216
217static struct inode *mqueue_alloc_inode(struct super_block *sb)
218{
219 struct mqueue_inode_info *ei;
220
Christoph Lametere94b1762006-12-06 20:33:17 -0800221 ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 if (!ei)
223 return NULL;
224 return &ei->vfs_inode;
225}
226
227static void mqueue_destroy_inode(struct inode *inode)
228{
229 kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
230}
231
232static void mqueue_delete_inode(struct inode *inode)
233{
234 struct mqueue_inode_info *info;
235 struct user_struct *user;
236 unsigned long mq_bytes;
237 int i;
238
239 if (S_ISDIR(inode->i_mode)) {
240 clear_inode(inode);
241 return;
242 }
243 info = MQUEUE_I(inode);
244 spin_lock(&info->lock);
245 for (i = 0; i < info->attr.mq_curmsgs; i++)
246 free_msg(info->messages[i]);
247 kfree(info->messages);
248 spin_unlock(&info->lock);
249
250 clear_inode(inode);
251
252 mq_bytes = (info->attr.mq_maxmsg * sizeof(struct msg_msg *) +
253 (info->attr.mq_maxmsg * info->attr.mq_msgsize));
254 user = info->user;
255 if (user) {
256 spin_lock(&mq_lock);
257 user->mq_bytes -= mq_bytes;
258 queues_count--;
259 spin_unlock(&mq_lock);
260 free_uid(user);
261 }
262}
263
264static int mqueue_create(struct inode *dir, struct dentry *dentry,
265 int mode, struct nameidata *nd)
266{
267 struct inode *inode;
268 struct mq_attr *attr = dentry->d_fsdata;
269 int error;
270
271 spin_lock(&mq_lock);
272 if (queues_count >= queues_max && !capable(CAP_SYS_RESOURCE)) {
273 error = -ENOSPC;
274 goto out_lock;
275 }
276 queues_count++;
277 spin_unlock(&mq_lock);
278
279 inode = mqueue_get_inode(dir->i_sb, mode, attr);
280 if (!inode) {
281 error = -ENOMEM;
282 spin_lock(&mq_lock);
283 queues_count--;
284 goto out_lock;
285 }
286
287 dir->i_size += DIRENT_SIZE;
288 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
289
290 d_instantiate(dentry, inode);
291 dget(dentry);
292 return 0;
293out_lock:
294 spin_unlock(&mq_lock);
295 return error;
296}
297
298static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
299{
300 struct inode *inode = dentry->d_inode;
301
302 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
303 dir->i_size -= DIRENT_SIZE;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700304 drop_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 dput(dentry);
306 return 0;
307}
308
309/*
310* This is routine for system read from queue file.
311* To avoid mess with doing here some sort of mq_receive we allow
312* to read only queue size & notification info (the only values
313* that are interesting from user point of view and aren't accessible
314* through std routines)
315*/
316static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
317 size_t count, loff_t * off)
318{
Josef Sipek6d630792006-12-08 02:37:11 -0800319 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 char buffer[FILENT_SIZE];
321 size_t slen;
322 loff_t o;
323
324 if (!count)
325 return 0;
326
327 spin_lock(&info->lock);
328 snprintf(buffer, sizeof(buffer),
329 "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
330 info->qsize,
331 info->notify_owner ? info->notify.sigev_notify : 0,
332 (info->notify_owner &&
333 info->notify.sigev_notify == SIGEV_SIGNAL) ?
334 info->notify.sigev_signo : 0,
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700335 pid_nr_ns(info->notify_owner,
336 current->nsproxy->pid_ns));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 spin_unlock(&info->lock);
338 buffer[sizeof(buffer)-1] = '\0';
339 slen = strlen(buffer)+1;
340
341 o = *off;
342 if (o > slen)
343 return 0;
344
345 if (o + count > slen)
346 count = slen - o;
347
348 if (copy_to_user(u_data, buffer + o, count))
349 return -EFAULT;
350
351 *off = o + count;
Josef Sipek6d630792006-12-08 02:37:11 -0800352 filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 return count;
354}
355
Miklos Szeredi75e1fcc2006-06-23 02:05:12 -0700356static int mqueue_flush_file(struct file *filp, fl_owner_t id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357{
Josef Sipek6d630792006-12-08 02:37:11 -0800358 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359
360 spin_lock(&info->lock);
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700361 if (task_tgid(current) == info->notify_owner)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 remove_notification(info);
363
364 spin_unlock(&info->lock);
365 return 0;
366}
367
368static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
369{
Josef Sipek6d630792006-12-08 02:37:11 -0800370 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 int retval = 0;
372
373 poll_wait(filp, &info->wait_q, poll_tab);
374
375 spin_lock(&info->lock);
376 if (info->attr.mq_curmsgs)
377 retval = POLLIN | POLLRDNORM;
378
379 if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
380 retval |= POLLOUT | POLLWRNORM;
381 spin_unlock(&info->lock);
382
383 return retval;
384}
385
386/* Adds current to info->e_wait_q[sr] before element with smaller prio */
387static void wq_add(struct mqueue_inode_info *info, int sr,
388 struct ext_wait_queue *ewp)
389{
390 struct ext_wait_queue *walk;
391
392 ewp->task = current;
393
394 list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
395 if (walk->task->static_prio <= current->static_prio) {
396 list_add_tail(&ewp->list, &walk->list);
397 return;
398 }
399 }
400 list_add_tail(&ewp->list, &info->e_wait_q[sr].list);
401}
402
403/*
404 * Puts current task to sleep. Caller must hold queue lock. After return
405 * lock isn't held.
406 * sr: SEND or RECV
407 */
408static int wq_sleep(struct mqueue_inode_info *info, int sr,
409 long timeout, struct ext_wait_queue *ewp)
410{
411 int retval;
412 signed long time;
413
414 wq_add(info, sr, ewp);
415
416 for (;;) {
417 set_current_state(TASK_INTERRUPTIBLE);
418
419 spin_unlock(&info->lock);
420 time = schedule_timeout(timeout);
421
422 while (ewp->state == STATE_PENDING)
423 cpu_relax();
424
425 if (ewp->state == STATE_READY) {
426 retval = 0;
427 goto out;
428 }
429 spin_lock(&info->lock);
430 if (ewp->state == STATE_READY) {
431 retval = 0;
432 goto out_unlock;
433 }
434 if (signal_pending(current)) {
435 retval = -ERESTARTSYS;
436 break;
437 }
438 if (time == 0) {
439 retval = -ETIMEDOUT;
440 break;
441 }
442 }
443 list_del(&ewp->list);
444out_unlock:
445 spin_unlock(&info->lock);
446out:
447 return retval;
448}
449
450/*
451 * Returns waiting task that should be serviced first or NULL if none exists
452 */
453static struct ext_wait_queue *wq_get_first_waiter(
454 struct mqueue_inode_info *info, int sr)
455{
456 struct list_head *ptr;
457
458 ptr = info->e_wait_q[sr].list.prev;
459 if (ptr == &info->e_wait_q[sr].list)
460 return NULL;
461 return list_entry(ptr, struct ext_wait_queue, list);
462}
463
464/* Auxiliary functions to manipulate messages' list */
465static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info)
466{
467 int k;
468
469 k = info->attr.mq_curmsgs - 1;
470 while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) {
471 info->messages[k + 1] = info->messages[k];
472 k--;
473 }
474 info->attr.mq_curmsgs++;
475 info->qsize += ptr->m_ts;
476 info->messages[k + 1] = ptr;
477}
478
479static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
480{
481 info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts;
482 return info->messages[info->attr.mq_curmsgs];
483}
484
485static inline void set_cookie(struct sk_buff *skb, char code)
486{
487 ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
488}
489
490/*
491 * The next function is only to split too long sys_mq_timedsend
492 */
493static void __do_notify(struct mqueue_inode_info *info)
494{
495 /* notification
496 * invoked when there is registered process and there isn't process
497 * waiting synchronously for message AND state of queue changed from
498 * empty to not empty. Here we are sure that no one is waiting
499 * synchronously. */
500 if (info->notify_owner &&
501 info->attr.mq_curmsgs == 1) {
502 struct siginfo sig_i;
503 switch (info->notify.sigev_notify) {
504 case SIGEV_NONE:
505 break;
506 case SIGEV_SIGNAL:
507 /* sends signal */
508
509 sig_i.si_signo = info->notify.sigev_signo;
510 sig_i.si_errno = 0;
511 sig_i.si_code = SI_MESGQ;
512 sig_i.si_value = info->notify.sigev_value;
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700513 sig_i.si_pid = task_pid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 sig_i.si_uid = current->uid;
515
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700516 kill_pid_info(info->notify.sigev_signo,
517 &sig_i, info->notify_owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 break;
519 case SIGEV_THREAD:
520 set_cookie(info->notify_cookie, NOTIFY_WOKENUP);
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700521 netlink_sendskb(info->notify_sock, info->notify_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 break;
523 }
524 /* after notification unregisters process */
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700525 put_pid(info->notify_owner);
526 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 }
528 wake_up(&info->wait_q);
529}
530
531static long prepare_timeout(const struct timespec __user *u_arg)
532{
533 struct timespec ts, nowts;
534 long timeout;
535
536 if (u_arg) {
537 if (unlikely(copy_from_user(&ts, u_arg,
538 sizeof(struct timespec))))
539 return -EFAULT;
540
541 if (unlikely(ts.tv_nsec < 0 || ts.tv_sec < 0
542 || ts.tv_nsec >= NSEC_PER_SEC))
543 return -EINVAL;
544 nowts = CURRENT_TIME;
545 /* first subtract as jiffies can't be too big */
546 ts.tv_sec -= nowts.tv_sec;
547 if (ts.tv_nsec < nowts.tv_nsec) {
548 ts.tv_nsec += NSEC_PER_SEC;
549 ts.tv_sec--;
550 }
551 ts.tv_nsec -= nowts.tv_nsec;
552 if (ts.tv_sec < 0)
553 return 0;
554
555 timeout = timespec_to_jiffies(&ts) + 1;
556 } else
557 return MAX_SCHEDULE_TIMEOUT;
558
559 return timeout;
560}
561
562static void remove_notification(struct mqueue_inode_info *info)
563{
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700564 if (info->notify_owner != NULL &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 info->notify.sigev_notify == SIGEV_THREAD) {
566 set_cookie(info->notify_cookie, NOTIFY_REMOVED);
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700567 netlink_sendskb(info->notify_sock, info->notify_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700569 put_pid(info->notify_owner);
570 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571}
572
573static int mq_attr_ok(struct mq_attr *attr)
574{
575 if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
576 return 0;
577 if (capable(CAP_SYS_RESOURCE)) {
578 if (attr->mq_maxmsg > HARD_MSGMAX)
579 return 0;
580 } else {
581 if (attr->mq_maxmsg > msg_max ||
582 attr->mq_msgsize > msgsize_max)
583 return 0;
584 }
585 /* check for overflow */
586 if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
587 return 0;
588 if ((unsigned long)(attr->mq_maxmsg * attr->mq_msgsize) +
589 (attr->mq_maxmsg * sizeof (struct msg_msg *)) <
590 (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize))
591 return 0;
592 return 1;
593}
594
595/*
596 * Invoked when creating a new queue via sys_mq_open
597 */
598static struct file *do_create(struct dentry *dir, struct dentry *dentry,
599 int oflag, mode_t mode, struct mq_attr __user *u_attr)
600{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 struct mq_attr attr;
602 int ret;
603
Alexander Viro7c7dce92006-01-14 15:29:55 -0500604 if (u_attr) {
605 ret = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 if (copy_from_user(&attr, u_attr, sizeof(attr)))
Alexander Viro7c7dce92006-01-14 15:29:55 -0500607 goto out;
608 ret = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 if (!mq_attr_ok(&attr))
Alexander Viro7c7dce92006-01-14 15:29:55 -0500610 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 /* store for use during create */
612 dentry->d_fsdata = &attr;
613 }
614
Krzysztof Benedyczak59175832005-09-27 22:21:36 +0200615 mode &= ~current->fs->umask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 ret = vfs_create(dir->d_inode, dentry, mode, NULL);
617 dentry->d_fsdata = NULL;
618 if (ret)
Alexander Viro7c7dce92006-01-14 15:29:55 -0500619 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620
Alexander Viro7c7dce92006-01-14 15:29:55 -0500621 return dentry_open(dentry, mqueue_mnt, oflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622
Alexander Viro7c7dce92006-01-14 15:29:55 -0500623out:
624 dput(dentry);
625 mntput(mqueue_mnt);
626 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627}
628
629/* Opens existing queue */
630static struct file *do_open(struct dentry *dentry, int oflag)
631{
632static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
633 MAY_READ | MAY_WRITE };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634
Alexander Viro7c7dce92006-01-14 15:29:55 -0500635 if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
636 dput(dentry);
637 mntput(mqueue_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 return ERR_PTR(-EINVAL);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500639 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640
Alexander Viro7c7dce92006-01-14 15:29:55 -0500641 if (permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE], NULL)) {
642 dput(dentry);
643 mntput(mqueue_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 return ERR_PTR(-EACCES);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500645 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646
Alexander Viro7c7dce92006-01-14 15:29:55 -0500647 return dentry_open(dentry, mqueue_mnt, oflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648}
649
650asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
651 struct mq_attr __user *u_attr)
652{
653 struct dentry *dentry;
654 struct file *filp;
655 char *name;
656 int fd, error;
657
George C. Wilson20ca73b2006-05-24 16:09:55 -0500658 error = audit_mq_open(oflag, mode, u_attr);
659 if (error != 0)
660 return error;
661
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 if (IS_ERR(name = getname(u_name)))
663 return PTR_ERR(name);
664
665 fd = get_unused_fd();
666 if (fd < 0)
667 goto out_putname;
668
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800669 mutex_lock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
671 if (IS_ERR(dentry)) {
672 error = PTR_ERR(dentry);
673 goto out_err;
674 }
675 mntget(mqueue_mnt);
676
677 if (oflag & O_CREAT) {
678 if (dentry->d_inode) { /* entry already exists */
Al Viro5a190ae2007-06-07 12:19:32 -0400679 audit_inode(name, dentry);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500680 error = -EEXIST;
681 if (oflag & O_EXCL)
682 goto out;
683 filp = do_open(dentry, oflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 } else {
685 filp = do_create(mqueue_mnt->mnt_root, dentry,
686 oflag, mode, u_attr);
687 }
Alexander Viro7c7dce92006-01-14 15:29:55 -0500688 } else {
689 error = -ENOENT;
690 if (!dentry->d_inode)
691 goto out;
Al Viro5a190ae2007-06-07 12:19:32 -0400692 audit_inode(name, dentry);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500693 filp = do_open(dentry, oflag);
694 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695
696 if (IS_ERR(filp)) {
697 error = PTR_ERR(filp);
698 goto out_putfd;
699 }
700
701 set_close_on_exec(fd, 1);
702 fd_install(fd, filp);
703 goto out_upsem;
704
Alexander Viro7c7dce92006-01-14 15:29:55 -0500705out:
706 dput(dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 mntput(mqueue_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500708out_putfd:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 put_unused_fd(fd);
710out_err:
711 fd = error;
712out_upsem:
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800713 mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714out_putname:
715 putname(name);
716 return fd;
717}
718
719asmlinkage long sys_mq_unlink(const char __user *u_name)
720{
721 int err;
722 char *name;
723 struct dentry *dentry;
724 struct inode *inode = NULL;
725
726 name = getname(u_name);
727 if (IS_ERR(name))
728 return PTR_ERR(name);
729
Peter Zijlstra7a434812007-03-06 01:42:09 -0800730 mutex_lock_nested(&mqueue_mnt->mnt_root->d_inode->i_mutex,
731 I_MUTEX_PARENT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
733 if (IS_ERR(dentry)) {
734 err = PTR_ERR(dentry);
735 goto out_unlock;
736 }
737
738 if (!dentry->d_inode) {
739 err = -ENOENT;
740 goto out_err;
741 }
742
743 inode = dentry->d_inode;
744 if (inode)
745 atomic_inc(&inode->i_count);
746
747 err = vfs_unlink(dentry->d_parent->d_inode, dentry);
748out_err:
749 dput(dentry);
750
751out_unlock:
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800752 mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 putname(name);
754 if (inode)
755 iput(inode);
756
757 return err;
758}
759
760/* Pipelined send and receive functions.
761 *
762 * If a receiver finds no waiting message, then it registers itself in the
763 * list of waiting receivers. A sender checks that list before adding the new
764 * message into the message array. If there is a waiting receiver, then it
765 * bypasses the message array and directly hands the message over to the
766 * receiver.
767 * The receiver accepts the message and returns without grabbing the queue
768 * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers
769 * are necessary. The same algorithm is used for sysv semaphores, see
Serge E. Hallyn7b7a3172006-03-28 01:56:23 -0800770 * ipc/sem.c for more details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 *
772 * The same algorithm is used for senders.
773 */
774
775/* pipelined_send() - send a message directly to the task waiting in
776 * sys_mq_timedreceive() (without inserting message into a queue).
777 */
778static inline void pipelined_send(struct mqueue_inode_info *info,
779 struct msg_msg *message,
780 struct ext_wait_queue *receiver)
781{
782 receiver->msg = message;
783 list_del(&receiver->list);
784 receiver->state = STATE_PENDING;
785 wake_up_process(receiver->task);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700786 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 receiver->state = STATE_READY;
788}
789
790/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
791 * gets its message and put to the queue (we have one free place for sure). */
792static inline void pipelined_receive(struct mqueue_inode_info *info)
793{
794 struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);
795
796 if (!sender) {
797 /* for poll */
798 wake_up_interruptible(&info->wait_q);
799 return;
800 }
801 msg_insert(sender->msg, info);
802 list_del(&sender->list);
803 sender->state = STATE_PENDING;
804 wake_up_process(sender->task);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700805 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 sender->state = STATE_READY;
807}
808
809asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
810 size_t msg_len, unsigned int msg_prio,
811 const struct timespec __user *u_abs_timeout)
812{
813 struct file *filp;
814 struct inode *inode;
815 struct ext_wait_queue wait;
816 struct ext_wait_queue *receiver;
817 struct msg_msg *msg_ptr;
818 struct mqueue_inode_info *info;
819 long timeout;
820 int ret;
821
George C. Wilson20ca73b2006-05-24 16:09:55 -0500822 ret = audit_mq_timedsend(mqdes, msg_len, msg_prio, u_abs_timeout);
823 if (ret != 0)
824 return ret;
825
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
827 return -EINVAL;
828
829 timeout = prepare_timeout(u_abs_timeout);
830
831 ret = -EBADF;
832 filp = fget(mqdes);
833 if (unlikely(!filp))
834 goto out;
835
Josef Sipek6d630792006-12-08 02:37:11 -0800836 inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 if (unlikely(filp->f_op != &mqueue_file_operations))
838 goto out_fput;
839 info = MQUEUE_I(inode);
Al Viro5a190ae2007-06-07 12:19:32 -0400840 audit_inode(NULL, filp->f_path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841
842 if (unlikely(!(filp->f_mode & FMODE_WRITE)))
843 goto out_fput;
844
845 if (unlikely(msg_len > info->attr.mq_msgsize)) {
846 ret = -EMSGSIZE;
847 goto out_fput;
848 }
849
850 /* First try to allocate memory, before doing anything with
851 * existing queues. */
852 msg_ptr = load_msg(u_msg_ptr, msg_len);
853 if (IS_ERR(msg_ptr)) {
854 ret = PTR_ERR(msg_ptr);
855 goto out_fput;
856 }
857 msg_ptr->m_ts = msg_len;
858 msg_ptr->m_type = msg_prio;
859
860 spin_lock(&info->lock);
861
862 if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
863 if (filp->f_flags & O_NONBLOCK) {
864 spin_unlock(&info->lock);
865 ret = -EAGAIN;
866 } else if (unlikely(timeout < 0)) {
867 spin_unlock(&info->lock);
868 ret = timeout;
869 } else {
870 wait.task = current;
871 wait.msg = (void *) msg_ptr;
872 wait.state = STATE_NONE;
873 ret = wq_sleep(info, SEND, timeout, &wait);
874 }
875 if (ret < 0)
876 free_msg(msg_ptr);
877 } else {
878 receiver = wq_get_first_waiter(info, RECV);
879 if (receiver) {
880 pipelined_send(info, msg_ptr, receiver);
881 } else {
882 /* adds message to the queue */
883 msg_insert(msg_ptr, info);
884 __do_notify(info);
885 }
886 inode->i_atime = inode->i_mtime = inode->i_ctime =
887 CURRENT_TIME;
888 spin_unlock(&info->lock);
889 ret = 0;
890 }
891out_fput:
892 fput(filp);
893out:
894 return ret;
895}
896
897asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
898 size_t msg_len, unsigned int __user *u_msg_prio,
899 const struct timespec __user *u_abs_timeout)
900{
901 long timeout;
902 ssize_t ret;
903 struct msg_msg *msg_ptr;
904 struct file *filp;
905 struct inode *inode;
906 struct mqueue_inode_info *info;
907 struct ext_wait_queue wait;
908
George C. Wilson20ca73b2006-05-24 16:09:55 -0500909 ret = audit_mq_timedreceive(mqdes, msg_len, u_msg_prio, u_abs_timeout);
910 if (ret != 0)
911 return ret;
912
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 timeout = prepare_timeout(u_abs_timeout);
914
915 ret = -EBADF;
916 filp = fget(mqdes);
917 if (unlikely(!filp))
918 goto out;
919
Josef Sipek6d630792006-12-08 02:37:11 -0800920 inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 if (unlikely(filp->f_op != &mqueue_file_operations))
922 goto out_fput;
923 info = MQUEUE_I(inode);
Al Viro5a190ae2007-06-07 12:19:32 -0400924 audit_inode(NULL, filp->f_path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925
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 }
971out_fput:
972 fput(filp);
973out:
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 */
982asmlinkage 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
George C. Wilson20ca73b2006-05-24 16:09:55 -0500993 ret = audit_mq_notify(mqdes, u_notification);
994 if (ret != 0)
995 return ret;
996
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 nc = NULL;
998 sock = NULL;
999 if (u_notification != NULL) {
1000 if (copy_from_user(&notification, 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 &&
Jesper Juhl7ed20e12005-05-01 08:59:14 -07001009 !valid_signal(notification.sigev_signo)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 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 */
1028retry:
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
Alexey Kuznetsova70ea992006-02-09 16:40:11 -08001041 ret = netlink_attachskb(sock, nc, 0,
1042 MAX_SCHEDULE_TIMEOUT, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043 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
Josef Sipek6d630792006-12-08 02:37:11 -08001058 inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059 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) {
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001066 if (info->notify_owner == task_tgid(current)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 remove_notification(info);
1068 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1069 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001070 } else if (info->notify_owner != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 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 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001090
1091 info->notify_owner = get_pid(task_tgid(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1093 }
1094 spin_unlock(&info->lock);
1095out_fput:
1096 fput(filp);
1097out:
1098 if (sock) {
1099 netlink_detachskb(sock, nc);
1100 } else if (nc) {
1101 dev_kfree_skb(nc);
1102 }
1103 return ret;
1104}
1105
1106asmlinkage long sys_mq_getsetattr(mqd_t mqdes,
1107 const struct mq_attr __user *u_mqstat,
1108 struct mq_attr __user *u_omqstat)
1109{
1110 int ret;
1111 struct mq_attr mqstat, omqstat;
1112 struct file *filp;
1113 struct inode *inode;
1114 struct mqueue_inode_info *info;
1115
1116 if (u_mqstat != NULL) {
1117 if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr)))
1118 return -EFAULT;
1119 if (mqstat.mq_flags & (~O_NONBLOCK))
1120 return -EINVAL;
1121 }
1122
1123 ret = -EBADF;
1124 filp = fget(mqdes);
1125 if (!filp)
1126 goto out;
1127
Josef Sipek6d630792006-12-08 02:37:11 -08001128 inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001129 if (unlikely(filp->f_op != &mqueue_file_operations))
1130 goto out_fput;
1131 info = MQUEUE_I(inode);
1132
1133 spin_lock(&info->lock);
1134
1135 omqstat = info->attr;
1136 omqstat.mq_flags = filp->f_flags & O_NONBLOCK;
1137 if (u_mqstat) {
George C. Wilson20ca73b2006-05-24 16:09:55 -05001138 ret = audit_mq_getsetattr(mqdes, &mqstat);
1139 if (ret != 0)
1140 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 if (mqstat.mq_flags & O_NONBLOCK)
1142 filp->f_flags |= O_NONBLOCK;
1143 else
1144 filp->f_flags &= ~O_NONBLOCK;
1145
1146 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1147 }
1148
1149 spin_unlock(&info->lock);
1150
1151 ret = 0;
1152 if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat,
1153 sizeof(struct mq_attr)))
1154 ret = -EFAULT;
1155
1156out_fput:
1157 fput(filp);
1158out:
1159 return ret;
1160}
1161
Arjan van de Ven92e1d5b2007-02-12 00:55:39 -08001162static const struct inode_operations mqueue_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163 .lookup = simple_lookup,
1164 .create = mqueue_create,
1165 .unlink = mqueue_unlink,
1166};
1167
Arjan van de Ven9a321442007-02-12 00:55:35 -08001168static const struct file_operations mqueue_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169 .flush = mqueue_flush_file,
1170 .poll = mqueue_poll_file,
1171 .read = mqueue_read_file,
1172};
1173
1174static struct super_operations mqueue_super_ops = {
1175 .alloc_inode = mqueue_alloc_inode,
1176 .destroy_inode = mqueue_destroy_inode,
1177 .statfs = simple_statfs,
1178 .delete_inode = mqueue_delete_inode,
1179 .drop_inode = generic_delete_inode,
1180};
1181
1182static struct file_system_type mqueue_fs_type = {
1183 .name = "mqueue",
1184 .get_sb = mqueue_get_sb,
1185 .kill_sb = kill_litter_super,
1186};
1187
1188static int msg_max_limit_min = DFLT_MSGMAX;
1189static int msg_max_limit_max = HARD_MSGMAX;
1190
1191static int msg_maxsize_limit_min = DFLT_MSGSIZEMAX;
1192static int msg_maxsize_limit_max = INT_MAX;
1193
1194static ctl_table mq_sysctls[] = {
1195 {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196 .procname = "queues_max",
1197 .data = &queues_max,
1198 .maxlen = sizeof(int),
1199 .mode = 0644,
1200 .proc_handler = &proc_dointvec,
1201 },
1202 {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203 .procname = "msg_max",
1204 .data = &msg_max,
1205 .maxlen = sizeof(int),
1206 .mode = 0644,
1207 .proc_handler = &proc_dointvec_minmax,
1208 .extra1 = &msg_max_limit_min,
1209 .extra2 = &msg_max_limit_max,
1210 },
1211 {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212 .procname = "msgsize_max",
1213 .data = &msgsize_max,
1214 .maxlen = sizeof(int),
1215 .mode = 0644,
1216 .proc_handler = &proc_dointvec_minmax,
1217 .extra1 = &msg_maxsize_limit_min,
1218 .extra2 = &msg_maxsize_limit_max,
1219 },
1220 { .ctl_name = 0 }
1221};
1222
1223static ctl_table mq_sysctl_dir[] = {
1224 {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225 .procname = "mqueue",
1226 .mode = 0555,
1227 .child = mq_sysctls,
1228 },
1229 { .ctl_name = 0 }
1230};
1231
1232static ctl_table mq_sysctl_root[] = {
1233 {
1234 .ctl_name = CTL_FS,
1235 .procname = "fs",
1236 .mode = 0555,
1237 .child = mq_sysctl_dir,
1238 },
1239 { .ctl_name = 0 }
1240};
1241
1242static int __init init_mqueue_fs(void)
1243{
1244 int error;
1245
1246 mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
1247 sizeof(struct mqueue_inode_info), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09001248 SLAB_HWCACHE_ALIGN, init_once);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249 if (mqueue_inode_cachep == NULL)
1250 return -ENOMEM;
1251
1252 /* ignore failues - they are not fatal */
Eric W. Biederman0b4d4142007-02-14 00:34:09 -08001253 mq_sysctl_table = register_sysctl_table(mq_sysctl_root);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254
1255 error = register_filesystem(&mqueue_fs_type);
1256 if (error)
1257 goto out_sysctl;
1258
1259 if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) {
1260 error = PTR_ERR(mqueue_mnt);
1261 goto out_filesystem;
1262 }
1263
1264 /* internal initialization - not common for vfs */
1265 queues_count = 0;
1266 spin_lock_init(&mq_lock);
1267
1268 return 0;
1269
1270out_filesystem:
1271 unregister_filesystem(&mqueue_fs_type);
1272out_sysctl:
1273 if (mq_sysctl_table)
1274 unregister_sysctl_table(mq_sysctl_table);
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -07001275 kmem_cache_destroy(mqueue_inode_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 return error;
1277}
1278
1279__initcall(init_mqueue_fs);