linux/fs/fcntl.c
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   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
  31static 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
  82static 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
 100int __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}
 112EXPORT_SYMBOL(__f_setown);
 113
 114int 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}
 131EXPORT_SYMBOL(f_setown);
 132
 133void f_delown(struct file *filp)
 134{
 135        f_modown(filp, NULL, PIDTYPE_PID, 1);
 136}
 137
 138pid_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
 149static 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
 189static 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
 226static 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
 244static int f_getowner_uids(struct file *filp, unsigned long arg)
 245{
 246        return -EINVAL;
 247}
 248#endif
 249
 250static 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
 335static 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
 348SYSCALL_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
 365out1:
 366        fdput(f);
 367out:
 368        return err;
 369}
 370
 371#if BITS_PER_LONG == 32
 372SYSCALL_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        }
 403out1:
 404        fdput(f);
 405out:
 406        return err;
 407}
 408#endif
 409
 410/* Table to convert sigio signal codes into poll band bitmaps */
 411
 412static 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
 421static 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
 437static 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
 479void 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
 507static 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
 514int 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
 546static DEFINE_SPINLOCK(fasync_lock);
 547static struct kmem_cache *fasync_cache __read_mostly;
 548
 549static 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 */
 564int 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
 590struct 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 */
 600void 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 */
 612struct 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
 636out:
 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 */
 646static 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 */
 675int 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
 682EXPORT_SYMBOL(fasync_helper);
 683
 684/*
 685 * rcu_read_lock() is held
 686 */
 687static 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
 712void 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}
 723EXPORT_SYMBOL(kill_fasync);
 724
 725static 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
 747module_init(fcntl_init)
 748