xref: /linux/fs/fcntl.c (revision 564eb714f5f09ac733c26860d5f0831f213fbdf1) 
1 /*
2  *  linux/fs/fcntl.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  */
6 
7 #include <linux/syscalls.h>
8 #include <linux/init.h>
9 #include <linux/mm.h>
10 #include <linux/fs.h>
11 #include <linux/file.h>
12 #include <linux/fdtable.h>
13 #include <linux/capability.h>
14 #include <linux/dnotify.h>
15 #include <linux/slab.h>
16 #include <linux/module.h>
17 #include <linux/pipe_fs_i.h>
18 #include <linux/security.h>
19 #include <linux/ptrace.h>
20 #include <linux/signal.h>
21 #include <linux/rcupdate.h>
22 #include <linux/pid_namespace.h>
23 #include <linux/user_namespace.h>
24 
25 #include <asm/poll.h>
26 #include <asm/siginfo.h>
27 #include <asm/uaccess.h>
28 
29 #define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME)
30 
31 static int setfl(int fd, struct file * filp, unsigned long arg)
32 {
33 	struct inode * inode = file_inode(filp);
34 	int error = 0;
35 
36 	/*
37 	 * O_APPEND cannot be cleared if the file is marked as append-only
38 	 * and the file is open for write.
39 	 */
40 	if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode))
41 		return -EPERM;
42 
43 	/* O_NOATIME can only be set by the owner or superuser */
44 	if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME))
45 		if (!inode_owner_or_capable(inode))
46 			return -EPERM;
47 
48 	/* required for strict SunOS emulation */
49 	if (O_NONBLOCK != O_NDELAY)
50 	       if (arg & O_NDELAY)
51 		   arg |= O_NONBLOCK;
52 
53 	if (arg & O_DIRECT) {
54 		if (!filp->f_mapping || !filp->f_mapping->a_ops ||
55 			!filp->f_mapping->a_ops->direct_IO)
56 				return -EINVAL;
57 	}
58 
59 	if (filp->f_op->check_flags)
60 		error = filp->f_op->check_flags(arg);
61 	if (error)
62 		return error;
63 
64 	/*
65 	 * ->fasync() is responsible for setting the FASYNC bit.
66 	 */
67 	if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op->fasync) {
68 		error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
69 		if (error < 0)
70 			goto out;
71 		if (error > 0)
72 			error = 0;
73 	}
74 	spin_lock(&filp->f_lock);
75 	filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
76 	spin_unlock(&filp->f_lock);
77 
78  out:
79 	return error;
80 }
81 
82 static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
83                      int force)
84 {
85 	write_lock_irq(&filp->f_owner.lock);
86 	if (force || !filp->f_owner.pid) {
87 		put_pid(filp->f_owner.pid);
88 		filp->f_owner.pid = get_pid(pid);
89 		filp->f_owner.pid_type = type;
90 
91 		if (pid) {
92 			const struct cred *cred = current_cred();
93 			filp->f_owner.uid = cred->uid;
94 			filp->f_owner.euid = cred->euid;
95 		}
96 	}
97 	write_unlock_irq(&filp->f_owner.lock);
98 }
99 
100 int __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
101 		int force)
102 {
103 	int err;
104 
105 	err = security_file_set_fowner(filp);
106 	if (err)
107 		return err;
108 
109 	f_modown(filp, pid, type, force);
110 	return 0;
111 }
112 EXPORT_SYMBOL(__f_setown);
113 
114 int f_setown(struct file *filp, unsigned long arg, int force)
115 {
116 	enum pid_type type;
117 	struct pid *pid;
118 	int who = arg;
119 	int result;
120 	type = PIDTYPE_PID;
121 	if (who < 0) {
122 		type = PIDTYPE_PGID;
123 		who = -who;
124 	}
125 	rcu_read_lock();
126 	pid = find_vpid(who);
127 	result = __f_setown(filp, pid, type, force);
128 	rcu_read_unlock();
129 	return result;
130 }
131 EXPORT_SYMBOL(f_setown);
132 
133 void f_delown(struct file *filp)
134 {
135 	f_modown(filp, NULL, PIDTYPE_PID, 1);
136 }
137 
138 pid_t f_getown(struct file *filp)
139 {
140 	pid_t pid;
141 	read_lock(&filp->f_owner.lock);
142 	pid = pid_vnr(filp->f_owner.pid);
143 	if (filp->f_owner.pid_type == PIDTYPE_PGID)
144 		pid = -pid;
145 	read_unlock(&filp->f_owner.lock);
146 	return pid;
147 }
148 
149 static int f_setown_ex(struct file *filp, unsigned long arg)
150 {
151 	struct f_owner_ex __user *owner_p = (void __user *)arg;
152 	struct f_owner_ex owner;
153 	struct pid *pid;
154 	int type;
155 	int ret;
156 
157 	ret = copy_from_user(&owner, owner_p, sizeof(owner));
158 	if (ret)
159 		return -EFAULT;
160 
161 	switch (owner.type) {
162 	case F_OWNER_TID:
163 		type = PIDTYPE_MAX;
164 		break;
165 
166 	case F_OWNER_PID:
167 		type = PIDTYPE_PID;
168 		break;
169 
170 	case F_OWNER_PGRP:
171 		type = PIDTYPE_PGID;
172 		break;
173 
174 	default:
175 		return -EINVAL;
176 	}
177 
178 	rcu_read_lock();
179 	pid = find_vpid(owner.pid);
180 	if (owner.pid && !pid)
181 		ret = -ESRCH;
182 	else
183 		ret = __f_setown(filp, pid, type, 1);
184 	rcu_read_unlock();
185 
186 	return ret;
187 }
188 
189 static int f_getown_ex(struct file *filp, unsigned long arg)
190 {
191 	struct f_owner_ex __user *owner_p = (void __user *)arg;
192 	struct f_owner_ex owner;
193 	int ret = 0;
194 
195 	read_lock(&filp->f_owner.lock);
196 	owner.pid = pid_vnr(filp->f_owner.pid);
197 	switch (filp->f_owner.pid_type) {
198 	case PIDTYPE_MAX:
199 		owner.type = F_OWNER_TID;
200 		break;
201 
202 	case PIDTYPE_PID:
203 		owner.type = F_OWNER_PID;
204 		break;
205 
206 	case PIDTYPE_PGID:
207 		owner.type = F_OWNER_PGRP;
208 		break;
209 
210 	default:
211 		WARN_ON(1);
212 		ret = -EINVAL;
213 		break;
214 	}
215 	read_unlock(&filp->f_owner.lock);
216 
217 	if (!ret) {
218 		ret = copy_to_user(owner_p, &owner, sizeof(owner));
219 		if (ret)
220 			ret = -EFAULT;
221 	}
222 	return ret;
223 }
224 
225 #ifdef CONFIG_CHECKPOINT_RESTORE
226 static int f_getowner_uids(struct file *filp, unsigned long arg)
227 {
228 	struct user_namespace *user_ns = current_user_ns();
229 	uid_t __user *dst = (void __user *)arg;
230 	uid_t src[2];
231 	int err;
232 
233 	read_lock(&filp->f_owner.lock);
234 	src[0] = from_kuid(user_ns, filp->f_owner.uid);
235 	src[1] = from_kuid(user_ns, filp->f_owner.euid);
236 	read_unlock(&filp->f_owner.lock);
237 
238 	err  = put_user(src[0], &dst[0]);
239 	err |= put_user(src[1], &dst[1]);
240 
241 	return err;
242 }
243 #else
244 static int f_getowner_uids(struct file *filp, unsigned long arg)
245 {
246 	return -EINVAL;
247 }
248 #endif
249 
250 static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
251 		struct file *filp)
252 {
253 	long err = -EINVAL;
254 
255 	switch (cmd) {
256 	case F_DUPFD:
257 		err = f_dupfd(arg, filp, 0);
258 		break;
259 	case F_DUPFD_CLOEXEC:
260 		err = f_dupfd(arg, filp, O_CLOEXEC);
261 		break;
262 	case F_GETFD:
263 		err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;
264 		break;
265 	case F_SETFD:
266 		err = 0;
267 		set_close_on_exec(fd, arg & FD_CLOEXEC);
268 		break;
269 	case F_GETFL:
270 		err = filp->f_flags;
271 		break;
272 	case F_SETFL:
273 		err = setfl(fd, filp, arg);
274 		break;
275 	case F_GETLK:
276 		err = fcntl_getlk(filp, (struct flock __user *) arg);
277 		break;
278 	case F_SETLK:
279 	case F_SETLKW:
280 		err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg);
281 		break;
282 	case F_GETOWN:
283 		/*
284 		 * XXX If f_owner is a process group, the
285 		 * negative return value will get converted
286 		 * into an error.  Oops.  If we keep the
287 		 * current syscall conventions, the only way
288 		 * to fix this will be in libc.
289 		 */
290 		err = f_getown(filp);
291 		force_successful_syscall_return();
292 		break;
293 	case F_SETOWN:
294 		err = f_setown(filp, arg, 1);
295 		break;
296 	case F_GETOWN_EX:
297 		err = f_getown_ex(filp, arg);
298 		break;
299 	case F_SETOWN_EX:
300 		err = f_setown_ex(filp, arg);
301 		break;
302 	case F_GETOWNER_UIDS:
303 		err = f_getowner_uids(filp, arg);
304 		break;
305 	case F_GETSIG:
306 		err = filp->f_owner.signum;
307 		break;
308 	case F_SETSIG:
309 		/* arg == 0 restores default behaviour. */
310 		if (!valid_signal(arg)) {
311 			break;
312 		}
313 		err = 0;
314 		filp->f_owner.signum = arg;
315 		break;
316 	case F_GETLEASE:
317 		err = fcntl_getlease(filp);
318 		break;
319 	case F_SETLEASE:
320 		err = fcntl_setlease(fd, filp, arg);
321 		break;
322 	case F_NOTIFY:
323 		err = fcntl_dirnotify(fd, filp, arg);
324 		break;
325 	case F_SETPIPE_SZ:
326 	case F_GETPIPE_SZ:
327 		err = pipe_fcntl(filp, cmd, arg);
328 		break;
329 	default:
330 		break;
331 	}
332 	return err;
333 }
334 
335 static int check_fcntl_cmd(unsigned cmd)
336 {
337 	switch (cmd) {
338 	case F_DUPFD:
339 	case F_DUPFD_CLOEXEC:
340 	case F_GETFD:
341 	case F_SETFD:
342 	case F_GETFL:
343 		return 1;
344 	}
345 	return 0;
346 }
347 
348 SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
349 {
350 	struct fd f = fdget_raw(fd);
351 	long err = -EBADF;
352 
353 	if (!f.file)
354 		goto out;
355 
356 	if (unlikely(f.file->f_mode & FMODE_PATH)) {
357 		if (!check_fcntl_cmd(cmd))
358 			goto out1;
359 	}
360 
361 	err = security_file_fcntl(f.file, cmd, arg);
362 	if (!err)
363 		err = do_fcntl(fd, cmd, arg, f.file);
364 
365 out1:
366  	fdput(f);
367 out:
368 	return err;
369 }
370 
371 #if BITS_PER_LONG == 32
372 SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
373 		unsigned long, arg)
374 {
375 	struct fd f = fdget_raw(fd);
376 	long err = -EBADF;
377 
378 	if (!f.file)
379 		goto out;
380 
381 	if (unlikely(f.file->f_mode & FMODE_PATH)) {
382 		if (!check_fcntl_cmd(cmd))
383 			goto out1;
384 	}
385 
386 	err = security_file_fcntl(f.file, cmd, arg);
387 	if (err)
388 		goto out1;
389 
390 	switch (cmd) {
391 		case F_GETLK64:
392 			err = fcntl_getlk64(f.file, (struct flock64 __user *) arg);
393 			break;
394 		case F_SETLK64:
395 		case F_SETLKW64:
396 			err = fcntl_setlk64(fd, f.file, cmd,
397 					(struct flock64 __user *) arg);
398 			break;
399 		default:
400 			err = do_fcntl(fd, cmd, arg, f.file);
401 			break;
402 	}
403 out1:
404 	fdput(f);
405 out:
406 	return err;
407 }
408 #endif
409 
410 /* Table to convert sigio signal codes into poll band bitmaps */
411 
412 static const long band_table[NSIGPOLL] = {
413 	POLLIN | POLLRDNORM,			/* POLL_IN */
414 	POLLOUT | POLLWRNORM | POLLWRBAND,	/* POLL_OUT */
415 	POLLIN | POLLRDNORM | POLLMSG,		/* POLL_MSG */
416 	POLLERR,				/* POLL_ERR */
417 	POLLPRI | POLLRDBAND,			/* POLL_PRI */
418 	POLLHUP | POLLERR			/* POLL_HUP */
419 };
420 
421 static inline int sigio_perm(struct task_struct *p,
422                              struct fown_struct *fown, int sig)
423 {
424 	const struct cred *cred;
425 	int ret;
426 
427 	rcu_read_lock();
428 	cred = __task_cred(p);
429 	ret = ((uid_eq(fown->euid, GLOBAL_ROOT_UID) ||
430 		uid_eq(fown->euid, cred->suid) || uid_eq(fown->euid, cred->uid) ||
431 		uid_eq(fown->uid,  cred->suid) || uid_eq(fown->uid,  cred->uid)) &&
432 	       !security_file_send_sigiotask(p, fown, sig));
433 	rcu_read_unlock();
434 	return ret;
435 }
436 
437 static void send_sigio_to_task(struct task_struct *p,
438 			       struct fown_struct *fown,
439 			       int fd, int reason, int group)
440 {
441 	/*
442 	 * F_SETSIG can change ->signum lockless in parallel, make
443 	 * sure we read it once and use the same value throughout.
444 	 */
445 	int signum = ACCESS_ONCE(fown->signum);
446 
447 	if (!sigio_perm(p, fown, signum))
448 		return;
449 
450 	switch (signum) {
451 		siginfo_t si;
452 		default:
453 			/* Queue a rt signal with the appropriate fd as its
454 			   value.  We use SI_SIGIO as the source, not
455 			   SI_KERNEL, since kernel signals always get
456 			   delivered even if we can't queue.  Failure to
457 			   queue in this case _should_ be reported; we fall
458 			   back to SIGIO in that case. --sct */
459 			si.si_signo = signum;
460 			si.si_errno = 0;
461 		        si.si_code  = reason;
462 			/* Make sure we are called with one of the POLL_*
463 			   reasons, otherwise we could leak kernel stack into
464 			   userspace.  */
465 			BUG_ON((reason & __SI_MASK) != __SI_POLL);
466 			if (reason - POLL_IN >= NSIGPOLL)
467 				si.si_band  = ~0L;
468 			else
469 				si.si_band = band_table[reason - POLL_IN];
470 			si.si_fd    = fd;
471 			if (!do_send_sig_info(signum, &si, p, group))
472 				break;
473 		/* fall-through: fall back on the old plain SIGIO signal */
474 		case 0:
475 			do_send_sig_info(SIGIO, SEND_SIG_PRIV, p, group);
476 	}
477 }
478 
479 void send_sigio(struct fown_struct *fown, int fd, int band)
480 {
481 	struct task_struct *p;
482 	enum pid_type type;
483 	struct pid *pid;
484 	int group = 1;
485 
486 	read_lock(&fown->lock);
487 
488 	type = fown->pid_type;
489 	if (type == PIDTYPE_MAX) {
490 		group = 0;
491 		type = PIDTYPE_PID;
492 	}
493 
494 	pid = fown->pid;
495 	if (!pid)
496 		goto out_unlock_fown;
497 
498 	read_lock(&tasklist_lock);
499 	do_each_pid_task(pid, type, p) {
500 		send_sigio_to_task(p, fown, fd, band, group);
501 	} while_each_pid_task(pid, type, p);
502 	read_unlock(&tasklist_lock);
503  out_unlock_fown:
504 	read_unlock(&fown->lock);
505 }
506 
507 static void send_sigurg_to_task(struct task_struct *p,
508 				struct fown_struct *fown, int group)
509 {
510 	if (sigio_perm(p, fown, SIGURG))
511 		do_send_sig_info(SIGURG, SEND_SIG_PRIV, p, group);
512 }
513 
514 int send_sigurg(struct fown_struct *fown)
515 {
516 	struct task_struct *p;
517 	enum pid_type type;
518 	struct pid *pid;
519 	int group = 1;
520 	int ret = 0;
521 
522 	read_lock(&fown->lock);
523 
524 	type = fown->pid_type;
525 	if (type == PIDTYPE_MAX) {
526 		group = 0;
527 		type = PIDTYPE_PID;
528 	}
529 
530 	pid = fown->pid;
531 	if (!pid)
532 		goto out_unlock_fown;
533 
534 	ret = 1;
535 
536 	read_lock(&tasklist_lock);
537 	do_each_pid_task(pid, type, p) {
538 		send_sigurg_to_task(p, fown, group);
539 	} while_each_pid_task(pid, type, p);
540 	read_unlock(&tasklist_lock);
541  out_unlock_fown:
542 	read_unlock(&fown->lock);
543 	return ret;
544 }
545 
546 static DEFINE_SPINLOCK(fasync_lock);
547 static struct kmem_cache *fasync_cache __read_mostly;
548 
549 static void fasync_free_rcu(struct rcu_head *head)
550 {
551 	kmem_cache_free(fasync_cache,
552 			container_of(head, struct fasync_struct, fa_rcu));
553 }
554 
555 /*
556  * Remove a fasync entry. If successfully removed, return
557  * positive and clear the FASYNC flag. If no entry exists,
558  * do nothing and return 0.
559  *
560  * NOTE! It is very important that the FASYNC flag always
561  * match the state "is the filp on a fasync list".
562  *
563  */
564 int fasync_remove_entry(struct file *filp, struct fasync_struct **fapp)
565 {
566 	struct fasync_struct *fa, **fp;
567 	int result = 0;
568 
569 	spin_lock(&filp->f_lock);
570 	spin_lock(&fasync_lock);
571 	for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
572 		if (fa->fa_file != filp)
573 			continue;
574 
575 		spin_lock_irq(&fa->fa_lock);
576 		fa->fa_file = NULL;
577 		spin_unlock_irq(&fa->fa_lock);
578 
579 		*fp = fa->fa_next;
580 		call_rcu(&fa->fa_rcu, fasync_free_rcu);
581 		filp->f_flags &= ~FASYNC;
582 		result = 1;
583 		break;
584 	}
585 	spin_unlock(&fasync_lock);
586 	spin_unlock(&filp->f_lock);
587 	return result;
588 }
589 
590 struct fasync_struct *fasync_alloc(void)
591 {
592 	return kmem_cache_alloc(fasync_cache, GFP_KERNEL);
593 }
594 
595 /*
596  * NOTE! This can be used only for unused fasync entries:
597  * entries that actually got inserted on the fasync list
598  * need to be released by rcu - see fasync_remove_entry.
599  */
600 void fasync_free(struct fasync_struct *new)
601 {
602 	kmem_cache_free(fasync_cache, new);
603 }
604 
605 /*
606  * Insert a new entry into the fasync list.  Return the pointer to the
607  * old one if we didn't use the new one.
608  *
609  * NOTE! It is very important that the FASYNC flag always
610  * match the state "is the filp on a fasync list".
611  */
612 struct fasync_struct *fasync_insert_entry(int fd, struct file *filp, struct fasync_struct **fapp, struct fasync_struct *new)
613 {
614         struct fasync_struct *fa, **fp;
615 
616 	spin_lock(&filp->f_lock);
617 	spin_lock(&fasync_lock);
618 	for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
619 		if (fa->fa_file != filp)
620 			continue;
621 
622 		spin_lock_irq(&fa->fa_lock);
623 		fa->fa_fd = fd;
624 		spin_unlock_irq(&fa->fa_lock);
625 		goto out;
626 	}
627 
628 	spin_lock_init(&new->fa_lock);
629 	new->magic = FASYNC_MAGIC;
630 	new->fa_file = filp;
631 	new->fa_fd = fd;
632 	new->fa_next = *fapp;
633 	rcu_assign_pointer(*fapp, new);
634 	filp->f_flags |= FASYNC;
635 
636 out:
637 	spin_unlock(&fasync_lock);
638 	spin_unlock(&filp->f_lock);
639 	return fa;
640 }
641 
642 /*
643  * Add a fasync entry. Return negative on error, positive if
644  * added, and zero if did nothing but change an existing one.
645  */
646 static int fasync_add_entry(int fd, struct file *filp, struct fasync_struct **fapp)
647 {
648 	struct fasync_struct *new;
649 
650 	new = fasync_alloc();
651 	if (!new)
652 		return -ENOMEM;
653 
654 	/*
655 	 * fasync_insert_entry() returns the old (update) entry if
656 	 * it existed.
657 	 *
658 	 * So free the (unused) new entry and return 0 to let the
659 	 * caller know that we didn't add any new fasync entries.
660 	 */
661 	if (fasync_insert_entry(fd, filp, fapp, new)) {
662 		fasync_free(new);
663 		return 0;
664 	}
665 
666 	return 1;
667 }
668 
669 /*
670  * fasync_helper() is used by almost all character device drivers
671  * to set up the fasync queue, and for regular files by the file
672  * lease code. It returns negative on error, 0 if it did no changes
673  * and positive if it added/deleted the entry.
674  */
675 int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp)
676 {
677 	if (!on)
678 		return fasync_remove_entry(filp, fapp);
679 	return fasync_add_entry(fd, filp, fapp);
680 }
681 
682 EXPORT_SYMBOL(fasync_helper);
683 
684 /*
685  * rcu_read_lock() is held
686  */
687 static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band)
688 {
689 	while (fa) {
690 		struct fown_struct *fown;
691 		unsigned long flags;
692 
693 		if (fa->magic != FASYNC_MAGIC) {
694 			printk(KERN_ERR "kill_fasync: bad magic number in "
695 			       "fasync_struct!\n");
696 			return;
697 		}
698 		spin_lock_irqsave(&fa->fa_lock, flags);
699 		if (fa->fa_file) {
700 			fown = &fa->fa_file->f_owner;
701 			/* Don't send SIGURG to processes which have not set a
702 			   queued signum: SIGURG has its own default signalling
703 			   mechanism. */
704 			if (!(sig == SIGURG && fown->signum == 0))
705 				send_sigio(fown, fa->fa_fd, band);
706 		}
707 		spin_unlock_irqrestore(&fa->fa_lock, flags);
708 		fa = rcu_dereference(fa->fa_next);
709 	}
710 }
711 
712 void kill_fasync(struct fasync_struct **fp, int sig, int band)
713 {
714 	/* First a quick test without locking: usually
715 	 * the list is empty.
716 	 */
717 	if (*fp) {
718 		rcu_read_lock();
719 		kill_fasync_rcu(rcu_dereference(*fp), sig, band);
720 		rcu_read_unlock();
721 	}
722 }
723 EXPORT_SYMBOL(kill_fasync);
724 
725 static int __init fcntl_init(void)
726 {
727 	/*
728 	 * Please add new bits here to ensure allocation uniqueness.
729 	 * Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDELAY
730 	 * is defined as O_NONBLOCK on some platforms and not on others.
731 	 */
732 	BUILD_BUG_ON(20 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32(
733 		O_RDONLY	| O_WRONLY	| O_RDWR	|
734 		O_CREAT		| O_EXCL	| O_NOCTTY	|
735 		O_TRUNC		| O_APPEND	| /* O_NONBLOCK	| */
736 		__O_SYNC	| O_DSYNC	| FASYNC	|
737 		O_DIRECT	| O_LARGEFILE	| O_DIRECTORY	|
738 		O_NOFOLLOW	| O_NOATIME	| O_CLOEXEC	|
739 		__FMODE_EXEC	| O_PATH	| __O_TMPFILE
740 		));
741 
742 	fasync_cache = kmem_cache_create("fasync_cache",
743 		sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL);
744 	return 0;
745 }
746 
747 module_init(fcntl_init)
748