[PATCH] UFS: inode->i_sem is not released in error path
[linux-2.6/verdex.git] / fs / fcntl.c
blob9903bde475f2ec4877bd0f0f32e76b2939ebf81f
1 /*
2 * linux/fs/fcntl.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
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/dnotify.h>
13 #include <linux/smp_lock.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
16 #include <linux/security.h>
17 #include <linux/ptrace.h>
18 #include <linux/signal.h>
19 #include <linux/rcupdate.h>
21 #include <asm/poll.h>
22 #include <asm/siginfo.h>
23 #include <asm/uaccess.h>
25 void fastcall set_close_on_exec(unsigned int fd, int flag)
27 struct files_struct *files = current->files;
28 struct fdtable *fdt;
29 spin_lock(&files->file_lock);
30 fdt = files_fdtable(files);
31 if (flag)
32 FD_SET(fd, fdt->close_on_exec);
33 else
34 FD_CLR(fd, fdt->close_on_exec);
35 spin_unlock(&files->file_lock);
38 static inline int get_close_on_exec(unsigned int fd)
40 struct files_struct *files = current->files;
41 struct fdtable *fdt;
42 int res;
43 rcu_read_lock();
44 fdt = files_fdtable(files);
45 res = FD_ISSET(fd, fdt->close_on_exec);
46 rcu_read_unlock();
47 return res;
51 * locate_fd finds a free file descriptor in the open_fds fdset,
52 * expanding the fd arrays if necessary. Must be called with the
53 * file_lock held for write.
56 static int locate_fd(struct files_struct *files,
57 struct file *file, unsigned int orig_start)
59 unsigned int newfd;
60 unsigned int start;
61 int error;
62 struct fdtable *fdt;
64 error = -EINVAL;
65 if (orig_start >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
66 goto out;
68 repeat:
69 fdt = files_fdtable(files);
71 * Someone might have closed fd's in the range
72 * orig_start..fdt->next_fd
74 start = orig_start;
75 if (start < fdt->next_fd)
76 start = fdt->next_fd;
78 newfd = start;
79 if (start < fdt->max_fdset) {
80 newfd = find_next_zero_bit(fdt->open_fds->fds_bits,
81 fdt->max_fdset, start);
84 error = -EMFILE;
85 if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
86 goto out;
88 error = expand_files(files, newfd);
89 if (error < 0)
90 goto out;
93 * If we needed to expand the fs array we
94 * might have blocked - try again.
96 if (error)
97 goto repeat;
100 * We reacquired files_lock, so we are safe as long as
101 * we reacquire the fdtable pointer and use it while holding
102 * the lock, no one can free it during that time.
104 fdt = files_fdtable(files);
105 if (start <= fdt->next_fd)
106 fdt->next_fd = newfd + 1;
108 error = newfd;
110 out:
111 return error;
114 static int dupfd(struct file *file, unsigned int start)
116 struct files_struct * files = current->files;
117 struct fdtable *fdt;
118 int fd;
120 spin_lock(&files->file_lock);
121 fd = locate_fd(files, file, start);
122 if (fd >= 0) {
123 /* locate_fd() may have expanded fdtable, load the ptr */
124 fdt = files_fdtable(files);
125 FD_SET(fd, fdt->open_fds);
126 FD_CLR(fd, fdt->close_on_exec);
127 spin_unlock(&files->file_lock);
128 fd_install(fd, file);
129 } else {
130 spin_unlock(&files->file_lock);
131 fput(file);
134 return fd;
137 asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
139 int err = -EBADF;
140 struct file * file, *tofree;
141 struct files_struct * files = current->files;
142 struct fdtable *fdt;
144 spin_lock(&files->file_lock);
145 if (!(file = fcheck(oldfd)))
146 goto out_unlock;
147 err = newfd;
148 if (newfd == oldfd)
149 goto out_unlock;
150 err = -EBADF;
151 if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
152 goto out_unlock;
153 get_file(file); /* We are now finished with oldfd */
155 err = expand_files(files, newfd);
156 if (err < 0)
157 goto out_fput;
159 /* To avoid races with open() and dup(), we will mark the fd as
160 * in-use in the open-file bitmap throughout the entire dup2()
161 * process. This is quite safe: do_close() uses the fd array
162 * entry, not the bitmap, to decide what work needs to be
163 * done. --sct */
164 /* Doesn't work. open() might be there first. --AV */
166 /* Yes. It's a race. In user space. Nothing sane to do */
167 err = -EBUSY;
168 fdt = files_fdtable(files);
169 tofree = fdt->fd[newfd];
170 if (!tofree && FD_ISSET(newfd, fdt->open_fds))
171 goto out_fput;
173 rcu_assign_pointer(fdt->fd[newfd], file);
174 FD_SET(newfd, fdt->open_fds);
175 FD_CLR(newfd, fdt->close_on_exec);
176 spin_unlock(&files->file_lock);
178 if (tofree)
179 filp_close(tofree, files);
180 err = newfd;
181 out:
182 return err;
183 out_unlock:
184 spin_unlock(&files->file_lock);
185 goto out;
187 out_fput:
188 spin_unlock(&files->file_lock);
189 fput(file);
190 goto out;
193 asmlinkage long sys_dup(unsigned int fildes)
195 int ret = -EBADF;
196 struct file * file = fget(fildes);
198 if (file)
199 ret = dupfd(file, 0);
200 return ret;
203 #define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | FASYNC | O_DIRECT | O_NOATIME)
205 static int setfl(int fd, struct file * filp, unsigned long arg)
207 struct inode * inode = filp->f_dentry->d_inode;
208 int error = 0;
210 /* O_APPEND cannot be cleared if the file is marked as append-only */
211 if (!(arg & O_APPEND) && IS_APPEND(inode))
212 return -EPERM;
214 /* O_NOATIME can only be set by the owner or superuser */
215 if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME))
216 if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER))
217 return -EPERM;
219 /* required for strict SunOS emulation */
220 if (O_NONBLOCK != O_NDELAY)
221 if (arg & O_NDELAY)
222 arg |= O_NONBLOCK;
224 if (arg & O_DIRECT) {
225 if (!filp->f_mapping || !filp->f_mapping->a_ops ||
226 !filp->f_mapping->a_ops->direct_IO)
227 return -EINVAL;
230 if (filp->f_op && filp->f_op->check_flags)
231 error = filp->f_op->check_flags(arg);
232 if (error)
233 return error;
235 lock_kernel();
236 if ((arg ^ filp->f_flags) & FASYNC) {
237 if (filp->f_op && filp->f_op->fasync) {
238 error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
239 if (error < 0)
240 goto out;
244 filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
245 out:
246 unlock_kernel();
247 return error;
250 static void f_modown(struct file *filp, unsigned long pid,
251 uid_t uid, uid_t euid, int force)
253 write_lock_irq(&filp->f_owner.lock);
254 if (force || !filp->f_owner.pid) {
255 filp->f_owner.pid = pid;
256 filp->f_owner.uid = uid;
257 filp->f_owner.euid = euid;
259 write_unlock_irq(&filp->f_owner.lock);
262 int f_setown(struct file *filp, unsigned long arg, int force)
264 int err;
266 err = security_file_set_fowner(filp);
267 if (err)
268 return err;
270 f_modown(filp, arg, current->uid, current->euid, force);
271 return 0;
274 EXPORT_SYMBOL(f_setown);
276 void f_delown(struct file *filp)
278 f_modown(filp, 0, 0, 0, 1);
281 static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
282 struct file *filp)
284 long err = -EINVAL;
286 switch (cmd) {
287 case F_DUPFD:
288 get_file(filp);
289 err = dupfd(filp, arg);
290 break;
291 case F_GETFD:
292 err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;
293 break;
294 case F_SETFD:
295 err = 0;
296 set_close_on_exec(fd, arg & FD_CLOEXEC);
297 break;
298 case F_GETFL:
299 err = filp->f_flags;
300 break;
301 case F_SETFL:
302 err = setfl(fd, filp, arg);
303 break;
304 case F_GETLK:
305 err = fcntl_getlk(filp, (struct flock __user *) arg);
306 break;
307 case F_SETLK:
308 case F_SETLKW:
309 err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg);
310 break;
311 case F_GETOWN:
313 * XXX If f_owner is a process group, the
314 * negative return value will get converted
315 * into an error. Oops. If we keep the
316 * current syscall conventions, the only way
317 * to fix this will be in libc.
319 err = filp->f_owner.pid;
320 force_successful_syscall_return();
321 break;
322 case F_SETOWN:
323 err = f_setown(filp, arg, 1);
324 break;
325 case F_GETSIG:
326 err = filp->f_owner.signum;
327 break;
328 case F_SETSIG:
329 /* arg == 0 restores default behaviour. */
330 if (!valid_signal(arg)) {
331 break;
333 err = 0;
334 filp->f_owner.signum = arg;
335 break;
336 case F_GETLEASE:
337 err = fcntl_getlease(filp);
338 break;
339 case F_SETLEASE:
340 err = fcntl_setlease(fd, filp, arg);
341 break;
342 case F_NOTIFY:
343 err = fcntl_dirnotify(fd, filp, arg);
344 break;
345 default:
346 break;
348 return err;
351 asmlinkage long sys_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg)
353 struct file *filp;
354 long err = -EBADF;
356 filp = fget(fd);
357 if (!filp)
358 goto out;
360 err = security_file_fcntl(filp, cmd, arg);
361 if (err) {
362 fput(filp);
363 return err;
366 err = do_fcntl(fd, cmd, arg, filp);
368 fput(filp);
369 out:
370 return err;
373 #if BITS_PER_LONG == 32
374 asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg)
376 struct file * filp;
377 long err;
379 err = -EBADF;
380 filp = fget(fd);
381 if (!filp)
382 goto out;
384 err = security_file_fcntl(filp, cmd, arg);
385 if (err) {
386 fput(filp);
387 return err;
389 err = -EBADF;
391 switch (cmd) {
392 case F_GETLK64:
393 err = fcntl_getlk64(filp, (struct flock64 __user *) arg);
394 break;
395 case F_SETLK64:
396 case F_SETLKW64:
397 err = fcntl_setlk64(fd, filp, cmd,
398 (struct flock64 __user *) arg);
399 break;
400 default:
401 err = do_fcntl(fd, cmd, arg, filp);
402 break;
404 fput(filp);
405 out:
406 return err;
408 #endif
410 /* Table to convert sigio signal codes into poll band bitmaps */
412 static 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 */
421 static inline int sigio_perm(struct task_struct *p,
422 struct fown_struct *fown, int sig)
424 return (((fown->euid == 0) ||
425 (fown->euid == p->suid) || (fown->euid == p->uid) ||
426 (fown->uid == p->suid) || (fown->uid == p->uid)) &&
427 !security_file_send_sigiotask(p, fown, sig));
430 static void send_sigio_to_task(struct task_struct *p,
431 struct fown_struct *fown,
432 int fd,
433 int reason)
435 if (!sigio_perm(p, fown, fown->signum))
436 return;
438 switch (fown->signum) {
439 siginfo_t si;
440 default:
441 /* Queue a rt signal with the appropriate fd as its
442 value. We use SI_SIGIO as the source, not
443 SI_KERNEL, since kernel signals always get
444 delivered even if we can't queue. Failure to
445 queue in this case _should_ be reported; we fall
446 back to SIGIO in that case. --sct */
447 si.si_signo = fown->signum;
448 si.si_errno = 0;
449 si.si_code = reason;
450 /* Make sure we are called with one of the POLL_*
451 reasons, otherwise we could leak kernel stack into
452 userspace. */
453 if ((reason & __SI_MASK) != __SI_POLL)
454 BUG();
455 if (reason - POLL_IN >= NSIGPOLL)
456 si.si_band = ~0L;
457 else
458 si.si_band = band_table[reason - POLL_IN];
459 si.si_fd = fd;
460 if (!group_send_sig_info(fown->signum, &si, p))
461 break;
462 /* fall-through: fall back on the old plain SIGIO signal */
463 case 0:
464 group_send_sig_info(SIGIO, SEND_SIG_PRIV, p);
468 void send_sigio(struct fown_struct *fown, int fd, int band)
470 struct task_struct *p;
471 int pid;
473 read_lock(&fown->lock);
474 pid = fown->pid;
475 if (!pid)
476 goto out_unlock_fown;
478 read_lock(&tasklist_lock);
479 if (pid > 0) {
480 p = find_task_by_pid(pid);
481 if (p) {
482 send_sigio_to_task(p, fown, fd, band);
484 } else {
485 do_each_task_pid(-pid, PIDTYPE_PGID, p) {
486 send_sigio_to_task(p, fown, fd, band);
487 } while_each_task_pid(-pid, PIDTYPE_PGID, p);
489 read_unlock(&tasklist_lock);
490 out_unlock_fown:
491 read_unlock(&fown->lock);
494 static void send_sigurg_to_task(struct task_struct *p,
495 struct fown_struct *fown)
497 if (sigio_perm(p, fown, SIGURG))
498 group_send_sig_info(SIGURG, SEND_SIG_PRIV, p);
501 int send_sigurg(struct fown_struct *fown)
503 struct task_struct *p;
504 int pid, ret = 0;
506 read_lock(&fown->lock);
507 pid = fown->pid;
508 if (!pid)
509 goto out_unlock_fown;
511 ret = 1;
513 read_lock(&tasklist_lock);
514 if (pid > 0) {
515 p = find_task_by_pid(pid);
516 if (p) {
517 send_sigurg_to_task(p, fown);
519 } else {
520 do_each_task_pid(-pid, PIDTYPE_PGID, p) {
521 send_sigurg_to_task(p, fown);
522 } while_each_task_pid(-pid, PIDTYPE_PGID, p);
524 read_unlock(&tasklist_lock);
525 out_unlock_fown:
526 read_unlock(&fown->lock);
527 return ret;
530 static DEFINE_RWLOCK(fasync_lock);
531 static kmem_cache_t *fasync_cache;
534 * fasync_helper() is used by some character device drivers (mainly mice)
535 * to set up the fasync queue. It returns negative on error, 0 if it did
536 * no changes and positive if it added/deleted the entry.
538 int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp)
540 struct fasync_struct *fa, **fp;
541 struct fasync_struct *new = NULL;
542 int result = 0;
544 if (on) {
545 new = kmem_cache_alloc(fasync_cache, SLAB_KERNEL);
546 if (!new)
547 return -ENOMEM;
549 write_lock_irq(&fasync_lock);
550 for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
551 if (fa->fa_file == filp) {
552 if(on) {
553 fa->fa_fd = fd;
554 kmem_cache_free(fasync_cache, new);
555 } else {
556 *fp = fa->fa_next;
557 kmem_cache_free(fasync_cache, fa);
558 result = 1;
560 goto out;
564 if (on) {
565 new->magic = FASYNC_MAGIC;
566 new->fa_file = filp;
567 new->fa_fd = fd;
568 new->fa_next = *fapp;
569 *fapp = new;
570 result = 1;
572 out:
573 write_unlock_irq(&fasync_lock);
574 return result;
577 EXPORT_SYMBOL(fasync_helper);
579 void __kill_fasync(struct fasync_struct *fa, int sig, int band)
581 while (fa) {
582 struct fown_struct * fown;
583 if (fa->magic != FASYNC_MAGIC) {
584 printk(KERN_ERR "kill_fasync: bad magic number in "
585 "fasync_struct!\n");
586 return;
588 fown = &fa->fa_file->f_owner;
589 /* Don't send SIGURG to processes which have not set a
590 queued signum: SIGURG has its own default signalling
591 mechanism. */
592 if (!(sig == SIGURG && fown->signum == 0))
593 send_sigio(fown, fa->fa_fd, band);
594 fa = fa->fa_next;
598 EXPORT_SYMBOL(__kill_fasync);
600 void kill_fasync(struct fasync_struct **fp, int sig, int band)
602 /* First a quick test without locking: usually
603 * the list is empty.
605 if (*fp) {
606 read_lock(&fasync_lock);
607 /* reread *fp after obtaining the lock */
608 __kill_fasync(*fp, sig, band);
609 read_unlock(&fasync_lock);
612 EXPORT_SYMBOL(kill_fasync);
614 static int __init fasync_init(void)
616 fasync_cache = kmem_cache_create("fasync_cache",
617 sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL, NULL);
618 return 0;
621 module_init(fasync_init)