open.c 27.9 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1 2 3 4 5 6 7 8 9
/*
 *  linux/fs/open.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#include <linux/string.h>
#include <linux/mm.h>
#include <linux/file.h>
Al Viro's avatar
Al Viro committed
10
#include <linux/fdtable.h>
Linus Torvalds's avatar
Linus Torvalds committed
11
#include <linux/quotaops.h>
Robert Love's avatar
Robert Love committed
12
#include <linux/fsnotify.h>
Linus Torvalds's avatar
Linus Torvalds committed
13 14 15 16 17
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/namei.h>
#include <linux/backing-dev.h>
18
#include <linux/capability.h>
19
#include <linux/securebits.h>
Linus Torvalds's avatar
Linus Torvalds committed
20 21 22
#include <linux/security.h>
#include <linux/mount.h>
#include <linux/vfs.h>
23
#include <linux/fcntl.h>
Linus Torvalds's avatar
Linus Torvalds committed
24 25
#include <asm/uaccess.h>
#include <linux/fs.h>
26
#include <linux/personality.h>
Linus Torvalds's avatar
Linus Torvalds committed
27 28
#include <linux/pagemap.h>
#include <linux/syscalls.h>
29
#include <linux/rcupdate.h>
30
#include <linux/audit.h>
31
#include <linux/falloc.h>
Linus Torvalds's avatar
Linus Torvalds committed
32

33
int vfs_statfs(struct dentry *dentry, struct kstatfs *buf)
Linus Torvalds's avatar
Linus Torvalds committed
34 35 36
{
	int retval = -ENODEV;

37
	if (dentry) {
Linus Torvalds's avatar
Linus Torvalds committed
38
		retval = -ENOSYS;
39
		if (dentry->d_sb->s_op->statfs) {
Linus Torvalds's avatar
Linus Torvalds committed
40
			memset(buf, 0, sizeof(*buf));
41
			retval = security_sb_statfs(dentry);
Linus Torvalds's avatar
Linus Torvalds committed
42 43
			if (retval)
				return retval;
44
			retval = dentry->d_sb->s_op->statfs(dentry, buf);
Linus Torvalds's avatar
Linus Torvalds committed
45 46 47 48 49 50 51 52 53
			if (retval == 0 && buf->f_frsize == 0)
				buf->f_frsize = buf->f_bsize;
		}
	}
	return retval;
}

EXPORT_SYMBOL(vfs_statfs);

54
static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf)
Linus Torvalds's avatar
Linus Torvalds committed
55 56 57 58
{
	struct kstatfs st;
	int retval;

59
	retval = vfs_statfs(dentry, &st);
Linus Torvalds's avatar
Linus Torvalds committed
60 61 62 63 64 65 66
	if (retval)
		return retval;

	if (sizeof(*buf) == sizeof(st))
		memcpy(buf, &st, sizeof(st));
	else {
		if (sizeof buf->f_blocks == 4) {
Jon Tollefson's avatar
Jon Tollefson committed
67 68
			if ((st.f_blocks | st.f_bfree | st.f_bavail |
			     st.f_bsize | st.f_frsize) &
Linus Torvalds's avatar
Linus Torvalds committed
69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
			    0xffffffff00000000ULL)
				return -EOVERFLOW;
			/*
			 * f_files and f_ffree may be -1; it's okay to stuff
			 * that into 32 bits
			 */
			if (st.f_files != -1 &&
			    (st.f_files & 0xffffffff00000000ULL))
				return -EOVERFLOW;
			if (st.f_ffree != -1 &&
			    (st.f_ffree & 0xffffffff00000000ULL))
				return -EOVERFLOW;
		}

		buf->f_type = st.f_type;
		buf->f_bsize = st.f_bsize;
		buf->f_blocks = st.f_blocks;
		buf->f_bfree = st.f_bfree;
		buf->f_bavail = st.f_bavail;
		buf->f_files = st.f_files;
		buf->f_ffree = st.f_ffree;
		buf->f_fsid = st.f_fsid;
		buf->f_namelen = st.f_namelen;
		buf->f_frsize = st.f_frsize;
		memset(buf->f_spare, 0, sizeof(buf->f_spare));
	}
	return 0;
}

98
static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf)
Linus Torvalds's avatar
Linus Torvalds committed
99 100 101 102
{
	struct kstatfs st;
	int retval;

103
	retval = vfs_statfs(dentry, &st);
Linus Torvalds's avatar
Linus Torvalds committed
104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132
	if (retval)
		return retval;

	if (sizeof(*buf) == sizeof(st))
		memcpy(buf, &st, sizeof(st));
	else {
		buf->f_type = st.f_type;
		buf->f_bsize = st.f_bsize;
		buf->f_blocks = st.f_blocks;
		buf->f_bfree = st.f_bfree;
		buf->f_bavail = st.f_bavail;
		buf->f_files = st.f_files;
		buf->f_ffree = st.f_ffree;
		buf->f_fsid = st.f_fsid;
		buf->f_namelen = st.f_namelen;
		buf->f_frsize = st.f_frsize;
		memset(buf->f_spare, 0, sizeof(buf->f_spare));
	}
	return 0;
}

asmlinkage long sys_statfs(const char __user * path, struct statfs __user * buf)
{
	struct nameidata nd;
	int error;

	error = user_path_walk(path, &nd);
	if (!error) {
		struct statfs tmp;
133
		error = vfs_statfs_native(nd.path.dentry, &tmp);
Linus Torvalds's avatar
Linus Torvalds committed
134 135
		if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
			error = -EFAULT;
Jan Blunck's avatar
Jan Blunck committed
136
		path_put(&nd.path);
Linus Torvalds's avatar
Linus Torvalds committed
137 138 139 140 141 142 143 144 145 146 147 148 149 150 151
	}
	return error;
}


asmlinkage long sys_statfs64(const char __user *path, size_t sz, struct statfs64 __user *buf)
{
	struct nameidata nd;
	long error;

	if (sz != sizeof(*buf))
		return -EINVAL;
	error = user_path_walk(path, &nd);
	if (!error) {
		struct statfs64 tmp;
152
		error = vfs_statfs64(nd.path.dentry, &tmp);
Linus Torvalds's avatar
Linus Torvalds committed
153 154
		if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
			error = -EFAULT;
Jan Blunck's avatar
Jan Blunck committed
155
		path_put(&nd.path);
Linus Torvalds's avatar
Linus Torvalds committed
156 157 158 159 160 161 162 163 164 165 166 167 168 169 170
	}
	return error;
}


asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf)
{
	struct file * file;
	struct statfs tmp;
	int error;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;
171
	error = vfs_statfs_native(file->f_path.dentry, &tmp);
Linus Torvalds's avatar
Linus Torvalds committed
172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191
	if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
		error = -EFAULT;
	fput(file);
out:
	return error;
}

asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf)
{
	struct file * file;
	struct statfs64 tmp;
	int error;

	if (sz != sizeof(*buf))
		return -EINVAL;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;
192
	error = vfs_statfs64(file->f_path.dentry, &tmp);
Linus Torvalds's avatar
Linus Torvalds committed
193 194 195 196 197 198 199
	if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
		error = -EFAULT;
	fput(file);
out:
	return error;
}

200 201
int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
	struct file *filp)
Linus Torvalds's avatar
Linus Torvalds committed
202 203 204 205 206 207 208 209 210
{
	int err;
	struct iattr newattrs;

	/* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */
	if (length < 0)
		return -EINVAL;

	newattrs.ia_size = length;
211
	newattrs.ia_valid = ATTR_SIZE | time_attrs;
212 213 214 215
	if (filp) {
		newattrs.ia_file = filp;
		newattrs.ia_valid |= ATTR_FILE;
	}
Linus Torvalds's avatar
Linus Torvalds committed
216

217 218 219
	/* Remove suid/sgid on truncate too */
	newattrs.ia_valid |= should_remove_suid(dentry);

220
	mutex_lock(&dentry->d_inode->i_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
221
	err = notify_change(dentry, &newattrs);
222
	mutex_unlock(&dentry->d_inode->i_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
223 224 225
	return err;
}

226
static long do_sys_truncate(const char __user * path, loff_t length)
Linus Torvalds's avatar
Linus Torvalds committed
227 228 229 230 231 232 233 234 235 236 237 238
{
	struct nameidata nd;
	struct inode * inode;
	int error;

	error = -EINVAL;
	if (length < 0)	/* sorry, but loff_t says... */
		goto out;

	error = user_path_walk(path, &nd);
	if (error)
		goto out;
239
	inode = nd.path.dentry->d_inode;
Linus Torvalds's avatar
Linus Torvalds committed
240 241 242 243 244 245 246 247 248 249

	/* For directories it's -EISDIR, for other non-regulars - -EINVAL */
	error = -EISDIR;
	if (S_ISDIR(inode->i_mode))
		goto dput_and_out;

	error = -EINVAL;
	if (!S_ISREG(inode->i_mode))
		goto dput_and_out;

250
	error = mnt_want_write(nd.path.mnt);
Linus Torvalds's avatar
Linus Torvalds committed
251 252 253
	if (error)
		goto dput_and_out;

254 255 256
	error = vfs_permission(&nd, MAY_WRITE);
	if (error)
		goto mnt_drop_write_and_out;
Linus Torvalds's avatar
Linus Torvalds committed
257 258 259

	error = -EPERM;
	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
260
		goto mnt_drop_write_and_out;
Linus Torvalds's avatar
Linus Torvalds committed
261

262
	error = get_write_access(inode);
Linus Torvalds's avatar
Linus Torvalds committed
263
	if (error)
264
		goto mnt_drop_write_and_out;
Linus Torvalds's avatar
Linus Torvalds committed
265

266 267 268 269 270
	/*
	 * Make sure that there are no leases.  get_write_access() protects
	 * against the truncate racing with a lease-granting setlease().
	 */
	error = break_lease(inode, FMODE_WRITE);
Linus Torvalds's avatar
Linus Torvalds committed
271
	if (error)
272
		goto put_write_and_out;
Linus Torvalds's avatar
Linus Torvalds committed
273 274 275 276

	error = locks_verify_truncate(inode, NULL, length);
	if (!error) {
		DQUOT_INIT(inode);
277
		error = do_truncate(nd.path.dentry, length, 0, NULL);
Linus Torvalds's avatar
Linus Torvalds committed
278 279
	}

280 281
put_write_and_out:
	put_write_access(inode);
282 283
mnt_drop_write_and_out:
	mnt_drop_write(nd.path.mnt);
Linus Torvalds's avatar
Linus Torvalds committed
284
dput_and_out:
Jan Blunck's avatar
Jan Blunck committed
285
	path_put(&nd.path);
Linus Torvalds's avatar
Linus Torvalds committed
286 287 288 289 290 291 292 293 294 295
out:
	return error;
}

asmlinkage long sys_truncate(const char __user * path, unsigned long length)
{
	/* on 32-bit boxen it will cut the range 2^31--2^32-1 off */
	return do_sys_truncate(path, (long)length);
}

296
static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
Linus Torvalds's avatar
Linus Torvalds committed
297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314
{
	struct inode * inode;
	struct dentry *dentry;
	struct file * file;
	int error;

	error = -EINVAL;
	if (length < 0)
		goto out;
	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

	/* explicitly opened as large or we are on 64-bit box */
	if (file->f_flags & O_LARGEFILE)
		small = 0;

315
	dentry = file->f_path.dentry;
Linus Torvalds's avatar
Linus Torvalds committed
316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331
	inode = dentry->d_inode;
	error = -EINVAL;
	if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
		goto out_putf;

	error = -EINVAL;
	/* Cannot ftruncate over 2^31 bytes without large file support */
	if (small && length > MAX_NON_LFS)
		goto out_putf;

	error = -EPERM;
	if (IS_APPEND(inode))
		goto out_putf;

	error = locks_verify_truncate(inode, file, length);
	if (!error)
332
		error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file);
Linus Torvalds's avatar
Linus Torvalds committed
333 334 335 336 337 338 339 340
out_putf:
	fput(file);
out:
	return error;
}

asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length)
{
341
	long ret = do_sys_ftruncate(fd, length, 1);
342
	/* avoid REGPARM breakage on x86: */
343
	asmlinkage_protect(2, ret, fd, length);
344
	return ret;
Linus Torvalds's avatar
Linus Torvalds committed
345 346 347 348 349 350 351 352 353 354 355
}

/* LFS versions of truncate are only needed on 32 bit machines */
#if BITS_PER_LONG == 32
asmlinkage long sys_truncate64(const char __user * path, loff_t length)
{
	return do_sys_truncate(path, length);
}

asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length)
{
356
	long ret = do_sys_ftruncate(fd, length, 0);
357
	/* avoid REGPARM breakage on x86: */
358
	asmlinkage_protect(2, ret, fd, length);
359
	return ret;
Linus Torvalds's avatar
Linus Torvalds committed
360 361 362
}
#endif

363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412
asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len)
{
	struct file *file;
	struct inode *inode;
	long ret = -EINVAL;

	if (offset < 0 || len <= 0)
		goto out;

	/* Return error if mode is not supported */
	ret = -EOPNOTSUPP;
	if (mode && !(mode & FALLOC_FL_KEEP_SIZE))
		goto out;

	ret = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;
	if (!(file->f_mode & FMODE_WRITE))
		goto out_fput;
	/*
	 * Revalidate the write permissions, in case security policy has
	 * changed since the files were opened.
	 */
	ret = security_file_permission(file, MAY_WRITE);
	if (ret)
		goto out_fput;

	inode = file->f_path.dentry->d_inode;

	ret = -ESPIPE;
	if (S_ISFIFO(inode->i_mode))
		goto out_fput;

	ret = -ENODEV;
	/*
	 * Let individual file system decide if it supports preallocation
	 * for directories or not.
	 */
	if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
		goto out_fput;

	ret = -EFBIG;
	/* Check for wrap through zero too */
	if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
		goto out_fput;

	if (inode->i_op && inode->i_op->fallocate)
		ret = inode->i_op->fallocate(inode, mode, offset, len);
	else
413
		ret = -EOPNOTSUPP;
414 415 416 417 418 419 420

out_fput:
	fput(file);
out:
	return ret;
}

Linus Torvalds's avatar
Linus Torvalds committed
421 422 423 424 425
/*
 * access() needs to use the real uid/gid, not the effective uid/gid.
 * We do this by temporarily clearing all FS-related capabilities and
 * switching the fsuid/fsgid around to the real ones.
 */
426
asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
Linus Torvalds's avatar
Linus Torvalds committed
427 428 429
{
	struct nameidata nd;
	int old_fsuid, old_fsgid;
430
	kernel_cap_t uninitialized_var(old_cap);  /* !SECURE_NO_SETUID_FIXUP */
Linus Torvalds's avatar
Linus Torvalds committed
431 432 433 434 435 436 437 438 439 440 441
	int res;

	if (mode & ~S_IRWXO)	/* where's F_OK, X_OK, W_OK, R_OK? */
		return -EINVAL;

	old_fsuid = current->fsuid;
	old_fsgid = current->fsgid;

	current->fsuid = current->uid;
	current->fsgid = current->gid;

442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458
	if (!issecure(SECURE_NO_SETUID_FIXUP)) {
		/*
		 * Clear the capabilities if we switch to a non-root user
		 */
#ifndef CONFIG_SECURITY_FILE_CAPABILITIES
		/*
		 * FIXME: There is a race here against sys_capset.  The
		 * capabilities can change yet we will restore the old
		 * value below.  We should hold task_capabilities_lock,
		 * but we cannot because user_path_walk can sleep.
		 */
#endif /* ndef CONFIG_SECURITY_FILE_CAPABILITIES */
		if (current->uid)
			old_cap = cap_set_effective(__cap_empty_set);
		else
			old_cap = cap_set_effective(current->cap_permitted);
	}
Linus Torvalds's avatar
Linus Torvalds committed
459

460
	res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
461 462 463 464 465 466
	if (res)
		goto out;

	res = vfs_permission(&nd, mode);
	/* SuS v2 requires we report a read only fs too */
	if(res || !(mode & S_IWOTH) ||
467
	   special_file(nd.path.dentry->d_inode->i_mode))
468
		goto out_path_release;
469 470 471 472 473 474 475 476 477 478 479
	/*
	 * This is a rare case where using __mnt_is_readonly()
	 * is OK without a mnt_want/drop_write() pair.  Since
	 * no actual write to the fs is performed here, we do
	 * not need to telegraph to that to anyone.
	 *
	 * By doing this, we accept that this access is
	 * inherently racy and know that the fs may change
	 * state before we even see this result.
	 */
	if (__mnt_is_readonly(nd.path.mnt))
480
		res = -EROFS;
Linus Torvalds's avatar
Linus Torvalds committed
481

482
out_path_release:
Jan Blunck's avatar
Jan Blunck committed
483
	path_put(&nd.path);
484
out:
Linus Torvalds's avatar
Linus Torvalds committed
485 486
	current->fsuid = old_fsuid;
	current->fsgid = old_fsgid;
487 488 489

	if (!issecure(SECURE_NO_SETUID_FIXUP))
		cap_set_effective(old_cap);
Linus Torvalds's avatar
Linus Torvalds committed
490 491 492 493

	return res;
}

494 495 496 497 498
asmlinkage long sys_access(const char __user *filename, int mode)
{
	return sys_faccessat(AT_FDCWD, filename, mode);
}

Linus Torvalds's avatar
Linus Torvalds committed
499 500 501 502 503
asmlinkage long sys_chdir(const char __user * filename)
{
	struct nameidata nd;
	int error;

504 505
	error = __user_walk(filename,
			    LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_CHDIR, &nd);
Linus Torvalds's avatar
Linus Torvalds committed
506 507 508
	if (error)
		goto out;

509
	error = vfs_permission(&nd, MAY_EXEC);
Linus Torvalds's avatar
Linus Torvalds committed
510 511 512
	if (error)
		goto dput_and_out;

513
	set_fs_pwd(current->fs, &nd.path);
Linus Torvalds's avatar
Linus Torvalds committed
514 515

dput_and_out:
Jan Blunck's avatar
Jan Blunck committed
516
	path_put(&nd.path);
Linus Torvalds's avatar
Linus Torvalds committed
517 518 519 520 521 522 523 524 525 526 527 528 529 530 531
out:
	return error;
}

asmlinkage long sys_fchdir(unsigned int fd)
{
	struct file *file;
	struct inode *inode;
	int error;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

532
	inode = file->f_path.dentry->d_inode;
Linus Torvalds's avatar
Linus Torvalds committed
533 534 535 536 537

	error = -ENOTDIR;
	if (!S_ISDIR(inode->i_mode))
		goto out_putf;

538
	error = file_permission(file, MAY_EXEC);
Linus Torvalds's avatar
Linus Torvalds committed
539
	if (!error)
540
		set_fs_pwd(current->fs, &file->f_path);
Linus Torvalds's avatar
Linus Torvalds committed
541 542 543 544 545 546 547 548 549 550 551 552 553 554 555
out_putf:
	fput(file);
out:
	return error;
}

asmlinkage long sys_chroot(const char __user * filename)
{
	struct nameidata nd;
	int error;

	error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
	if (error)
		goto out;

556
	error = vfs_permission(&nd, MAY_EXEC);
Linus Torvalds's avatar
Linus Torvalds committed
557 558 559 560 561 562 563
	if (error)
		goto dput_and_out;

	error = -EPERM;
	if (!capable(CAP_SYS_CHROOT))
		goto dput_and_out;

564
	set_fs_root(current->fs, &nd.path);
Linus Torvalds's avatar
Linus Torvalds committed
565 566 567
	set_fs_altroot();
	error = 0;
dput_and_out:
Jan Blunck's avatar
Jan Blunck committed
568
	path_put(&nd.path);
Linus Torvalds's avatar
Linus Torvalds committed
569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584
out:
	return error;
}

asmlinkage long sys_fchmod(unsigned int fd, mode_t mode)
{
	struct inode * inode;
	struct dentry * dentry;
	struct file * file;
	int err = -EBADF;
	struct iattr newattrs;

	file = fget(fd);
	if (!file)
		goto out;

585
	dentry = file->f_path.dentry;
Linus Torvalds's avatar
Linus Torvalds committed
586 587
	inode = dentry->d_inode;

588
	audit_inode(NULL, dentry);
589

590 591
	err = mnt_want_write(file->f_path.mnt);
	if (err)
Linus Torvalds's avatar
Linus Torvalds committed
592 593 594
		goto out_putf;
	err = -EPERM;
	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
595
		goto out_drop_write;
596
	mutex_lock(&inode->i_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
597 598 599 600 601
	if (mode == (mode_t) -1)
		mode = inode->i_mode;
	newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
	newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
	err = notify_change(dentry, &newattrs);
602
	mutex_unlock(&inode->i_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
603

604 605
out_drop_write:
	mnt_drop_write(file->f_path.mnt);
Linus Torvalds's avatar
Linus Torvalds committed
606 607 608 609 610 611
out_putf:
	fput(file);
out:
	return err;
}

612 613
asmlinkage long sys_fchmodat(int dfd, const char __user *filename,
			     mode_t mode)
Linus Torvalds's avatar
Linus Torvalds committed
614 615 616 617 618 619
{
	struct nameidata nd;
	struct inode * inode;
	int error;
	struct iattr newattrs;

620
	error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd);
Linus Torvalds's avatar
Linus Torvalds committed
621 622
	if (error)
		goto out;
623
	inode = nd.path.dentry->d_inode;
Linus Torvalds's avatar
Linus Torvalds committed
624

625 626
	error = mnt_want_write(nd.path.mnt);
	if (error)
Linus Torvalds's avatar
Linus Torvalds committed
627 628 629 630
		goto dput_and_out;

	error = -EPERM;
	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
631
		goto out_drop_write;
Linus Torvalds's avatar
Linus Torvalds committed
632

633
	mutex_lock(&inode->i_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
634 635 636 637
	if (mode == (mode_t) -1)
		mode = inode->i_mode;
	newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
	newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
638
	error = notify_change(nd.path.dentry, &newattrs);
639
	mutex_unlock(&inode->i_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
640

641 642
out_drop_write:
	mnt_drop_write(nd.path.mnt);
Linus Torvalds's avatar
Linus Torvalds committed
643
dput_and_out:
Jan Blunck's avatar
Jan Blunck committed
644
	path_put(&nd.path);
Linus Torvalds's avatar
Linus Torvalds committed
645 646 647 648
out:
	return error;
}

649 650 651 652 653
asmlinkage long sys_chmod(const char __user *filename, mode_t mode)
{
	return sys_fchmodat(AT_FDCWD, filename, mode);
}

Linus Torvalds's avatar
Linus Torvalds committed
654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677
static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
{
	struct inode * inode;
	int error;
	struct iattr newattrs;

	error = -ENOENT;
	if (!(inode = dentry->d_inode)) {
		printk(KERN_ERR "chown_common: NULL inode\n");
		goto out;
	}
	error = -EPERM;
	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
		goto out;
	newattrs.ia_valid =  ATTR_CTIME;
	if (user != (uid_t) -1) {
		newattrs.ia_valid |= ATTR_UID;
		newattrs.ia_uid = user;
	}
	if (group != (gid_t) -1) {
		newattrs.ia_valid |= ATTR_GID;
		newattrs.ia_gid = group;
	}
	if (!S_ISDIR(inode->i_mode))
678 679
		newattrs.ia_valid |=
			ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
680
	mutex_lock(&inode->i_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
681
	error = notify_change(dentry, &newattrs);
682
	mutex_unlock(&inode->i_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
683 684 685 686 687 688 689 690 691 692
out:
	return error;
}

asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group)
{
	struct nameidata nd;
	int error;

	error = user_path_walk(filename, &nd);
693 694
	if (error)
		goto out;
695 696 697
	error = mnt_want_write(nd.path.mnt);
	if (error)
		goto out_release;
698
	error = chown_common(nd.path.dentry, user, group);
699 700
	mnt_drop_write(nd.path.mnt);
out_release:
Jan Blunck's avatar
Jan Blunck committed
701
	path_put(&nd.path);
702
out:
Linus Torvalds's avatar
Linus Torvalds committed
703 704 705
	return error;
}

706 707 708 709 710 711 712 713 714 715 716 717
asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user,
			     gid_t group, int flag)
{
	struct nameidata nd;
	int error = -EINVAL;
	int follow;

	if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
		goto out;

	follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
	error = __user_walk_fd(dfd, filename, follow, &nd);
718 719
	if (error)
		goto out;
720 721 722
	error = mnt_want_write(nd.path.mnt);
	if (error)
		goto out_release;
723
	error = chown_common(nd.path.dentry, user, group);
724 725
	mnt_drop_write(nd.path.mnt);
out_release:
Jan Blunck's avatar
Jan Blunck committed
726
	path_put(&nd.path);
727 728 729 730
out:
	return error;
}

Linus Torvalds's avatar
Linus Torvalds committed
731 732 733 734 735 736
asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group)
{
	struct nameidata nd;
	int error;

	error = user_path_walk_link(filename, &nd);
737 738
	if (error)
		goto out;
739 740 741
	error = mnt_want_write(nd.path.mnt);
	if (error)
		goto out_release;
742
	error = chown_common(nd.path.dentry, user, group);
743 744
	mnt_drop_write(nd.path.mnt);
out_release:
Jan Blunck's avatar
Jan Blunck committed
745
	path_put(&nd.path);
746
out:
Linus Torvalds's avatar
Linus Torvalds committed
747 748 749 750 751 752 753 754
	return error;
}


asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
{
	struct file * file;
	int error = -EBADF;
755
	struct dentry * dentry;
Linus Torvalds's avatar
Linus Torvalds committed
756 757

	file = fget(fd);
758 759 760
	if (!file)
		goto out;

761 762 763
	error = mnt_want_write(file->f_path.mnt);
	if (error)
		goto out_fput;
764
	dentry = file->f_path.dentry;
765
	audit_inode(NULL, dentry);
766
	error = chown_common(dentry, user, group);
767 768
	mnt_drop_write(file->f_path.mnt);
out_fput:
769 770
	fput(file);
out:
Linus Torvalds's avatar
Linus Torvalds committed
771 772 773
	return error;
}

774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802
/*
 * You have to be very careful that these write
 * counts get cleaned up in error cases and
 * upon __fput().  This should probably never
 * be called outside of __dentry_open().
 */
static inline int __get_file_write_access(struct inode *inode,
					  struct vfsmount *mnt)
{
	int error;
	error = get_write_access(inode);
	if (error)
		return error;
	/*
	 * Do not take mount writer counts on
	 * special files since no writes to
	 * the mount itself will occur.
	 */
	if (!special_file(inode->i_mode)) {
		/*
		 * Balanced in __fput()
		 */
		error = mnt_want_write(mnt);
		if (error)
			put_write_access(inode);
	}
	return error;
}

803
static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
804 805
					int flags, struct file *f,
					int (*open)(struct inode *, struct file *))
Linus Torvalds's avatar
Linus Torvalds committed
806 807 808 809 810
{
	struct inode *inode;
	int error;

	f->f_flags = flags;
811 812
	f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK |
				FMODE_PREAD | FMODE_PWRITE;
Linus Torvalds's avatar
Linus Torvalds committed
813 814
	inode = dentry->d_inode;
	if (f->f_mode & FMODE_WRITE) {
815
		error = __get_file_write_access(inode, mnt);
Linus Torvalds's avatar
Linus Torvalds committed
816 817
		if (error)
			goto cleanup_file;
818 819
		if (!special_file(inode->i_mode))
			file_take_write(f);
Linus Torvalds's avatar
Linus Torvalds committed
820 821 822
	}

	f->f_mapping = inode->i_mapping;
823 824
	f->f_path.dentry = dentry;
	f->f_path.mnt = mnt;
Linus Torvalds's avatar
Linus Torvalds committed
825 826 827 828
	f->f_pos = 0;
	f->f_op = fops_get(inode->i_fop);
	file_move(f, &inode->i_sb->s_files);

829 830 831 832
	error = security_dentry_open(f);
	if (error)
		goto cleanup_all;

833 834 835 836
	if (!open && f->f_op)
		open = f->f_op->open;
	if (open) {
		error = open(inode, f);
Linus Torvalds's avatar
Linus Torvalds committed
837 838 839
		if (error)
			goto cleanup_all;
	}
840

Linus Torvalds's avatar
Linus Torvalds committed
841 842 843 844 845 846
	f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);

	file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);

	/* NB: we're sure to have correct a_ops only after f_op->open */
	if (f->f_flags & O_DIRECT) {
847 848
		if (!f->f_mapping->a_ops ||
		    ((!f->f_mapping->a_ops->direct_IO) &&
849
		    (!f->f_mapping->a_ops->get_xip_mem))) {
Linus Torvalds's avatar
Linus Torvalds committed
850 851 852 853 854 855 856 857 858
			fput(f);
			f = ERR_PTR(-EINVAL);
		}
	}

	return f;

cleanup_all:
	fops_put(f->f_op);
859
	if (f->f_mode & FMODE_WRITE) {
Linus Torvalds's avatar
Linus Torvalds committed
860
		put_write_access(inode);
861 862 863 864 865 866 867 868
		if (!special_file(inode->i_mode)) {
			/*
			 * We don't consider this a real
			 * mnt_want/drop_write() pair
			 * because it all happenend right
			 * here, so just reset the state.
			 */
			file_reset_write(f);
869
			mnt_drop_write(mnt);
870
		}
871
	}
Linus Torvalds's avatar
Linus Torvalds committed
872
	file_kill(f);
873 874
	f->f_path.dentry = NULL;
	f->f_path.mnt = NULL;
Linus Torvalds's avatar
Linus Torvalds committed
875 876 877 878 879 880 881
cleanup_file:
	put_filp(f);
	dput(dentry);
	mntput(mnt);
	return ERR_PTR(error);
}

882 883 884 885 886 887 888 889 890 891
/**
 * lookup_instantiate_filp - instantiates the open intent filp
 * @nd: pointer to nameidata
 * @dentry: pointer to dentry
 * @open: open callback
 *
 * Helper for filesystems that want to use lookup open intents and pass back
 * a fully instantiated struct file to the caller.
 * This function is meant to be called from within a filesystem's
 * lookup method.
892 893 894 895
 * Beware of calling it for non-regular files! Those ->open methods might block
 * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo,
 * leading to a deadlock, as nobody can open that fifo anymore, because
 * another process to open fifo will block on locked parent when doing lookup).
896 897 898 899 900 901 902 903 904 905 906 907
 * Note that in case of error, nd->intent.open.file is destroyed, but the
 * path information remains valid.
 * If the open callback is set to NULL, then the standard f_op->open()
 * filesystem callback is substituted.
 */
struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
		int (*open)(struct inode *, struct file *))
{
	if (IS_ERR(nd->intent.open.file))
		goto out;
	if (IS_ERR(dentry))
		goto out_err;
908
	nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt),
909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934
					     nd->intent.open.flags - 1,
					     nd->intent.open.file,
					     open);
out:
	return nd->intent.open.file;
out_err:
	release_open_intent(nd);
	nd->intent.open.file = (struct file *)dentry;
	goto out;
}
EXPORT_SYMBOL_GPL(lookup_instantiate_filp);

/**
 * nameidata_to_filp - convert a nameidata to an open filp.
 * @nd: pointer to nameidata
 * @flags: open flags
 *
 * Note that this function destroys the original nameidata
 */
struct file *nameidata_to_filp(struct nameidata *nd, int flags)
{
	struct file *filp;

	/* Pick up the filp from the open intent */
	filp = nd->intent.open.file;
	/* Has the filesystem initialised the file for us? */
935
	if (filp->f_path.dentry == NULL)
936 937
		filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp,
				     NULL);
938
	else
Jan Blunck's avatar
Jan Blunck committed
939
		path_put(&nd->path);
940 941 942
	return filp;
}

943 944 945 946
/*
 * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
 * error.
 */
947 948 949 950 951
struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
{
	int error;
	struct file *f;

952 953 954 955 956 957 958 959 960 961 962 963
	/*
	 * We must always pass in a valid mount pointer.   Historically
	 * callers got away with not passing it, but we must enforce this at
	 * the earliest possible point now to avoid strange problems deep in the
	 * filesystem stack.
	 */
	if (!mnt) {
		printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__);
		dump_stack();
		return ERR_PTR(-EINVAL);
	}

964 965
	error = -ENFILE;
	f = get_empty_filp();
966 967 968
	if (f == NULL) {
		dput(dentry);
		mntput(mnt);
969
		return ERR_PTR(error);
970
	}
971

972
	return __dentry_open(dentry, mnt, flags, f, NULL);
973
}
Linus Torvalds's avatar
Linus Torvalds committed
974 975 976 977 978
EXPORT_SYMBOL(dentry_open);

/*
 * Find an empty file descriptor entry, and mark it busy.
 */
Ulrich Drepper's avatar
Ulrich Drepper committed
979
int get_unused_fd_flags(int flags)
Linus Torvalds's avatar
Linus Torvalds committed
980 981 982
{
	struct files_struct * files = current->files;
	int fd, error;
983
	struct fdtable *fdt;
Linus Torvalds's avatar
Linus Torvalds committed
984 985 986 987 988

  	error = -EMFILE;
	spin_lock(&files->file_lock);

repeat:
989
	fdt = files_fdtable(files);
990
	fd = find_next_zero_bit(fdt->open_fds->fds_bits, fdt->max_fds,
991
				files->next_fd);
Linus Torvalds's avatar
Linus Torvalds committed
992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013

	/*
	 * N.B. For clone tasks sharing a files structure, this test
	 * will limit the total number of files that can be opened.
	 */
	if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
		goto out;

	/* Do we need to expand the fd array or fd set?  */
	error = expand_files(files, fd);
	if (error < 0)
		goto out;

	if (error) {
		/*
	 	 * If we needed to expand the fs array we
		 * might have blocked - try again.
		 */
		error = -EMFILE;
		goto repeat;
	}

1014
	FD_SET(fd, fdt->open_fds);
Ulrich Drepper's avatar
Ulrich Drepper committed
1015 1016 1017 1018
	if (flags & O_CLOEXEC)
		FD_SET(fd, fdt->close_on_exec);
	else
		FD_CLR(fd, fdt->close_on_exec);
1019
	files->next_fd = fd + 1;
Linus Torvalds's avatar
Linus Torvalds committed
1020 1021
#if 1
	/* Sanity check */
1022
	if (fdt->fd[fd] != NULL) {
Linus Torvalds's avatar
Linus Torvalds committed
1023
		printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd);
1024
		fdt->fd[fd] = NULL;
Linus Torvalds's avatar
Linus Torvalds committed
1025 1026 1027 1028 1029 1030 1031 1032 1033
	}
#endif
	error = fd;

out:
	spin_unlock(&files->file_lock);
	return error;
}

Ulrich Drepper's avatar
Ulrich Drepper committed
1034 1035 1036 1037 1038
int get_unused_fd(void)
{
	return get_unused_fd_flags(0);
}

Linus Torvalds's avatar
Linus Torvalds committed
1039 1040
EXPORT_SYMBOL(get_unused_fd);

1041
static void __put_unused_fd(struct files_struct *files, unsigned int fd)
Linus Torvalds's avatar
Linus Torvalds committed
1042
{
1043 1044
	struct fdtable *fdt = files_fdtable(files);
	__FD_CLR(fd, fdt->open_fds);
1045 1046
	if (fd < files->next_fd)
		files->next_fd = fd;
Linus Torvalds's avatar
Linus Torvalds committed
1047 1048
}

1049
void put_unused_fd(unsigned int fd)
Linus Torvalds's avatar
Linus Torvalds committed
1050 1051 1052 1053 1054 1055 1056 1057 1058 1059
{
	struct files_struct *files = current->files;
	spin_lock(&files->file_lock);
	__put_unused_fd(files, fd);
	spin_unlock(&files->file_lock);
}

EXPORT_SYMBOL(put_unused_fd);

/*
1060
 * Install a file pointer in the fd array.
Linus Torvalds's avatar
Linus Torvalds committed
1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071
 *
 * The VFS is full of places where we drop the files lock between
 * setting the open_fds bitmap and installing the file in the file
 * array.  At any such point, we are vulnerable to a dup2() race
 * installing a file in the array before us.  We need to detect this and
 * fput() the struct file we are about to overwrite in this case.
 *
 * It should never happen - if we allow dup2() do it, _really_ bad things
 * will follow.
 */

1072
void fd_install(unsigned int fd, struct file *file)
Linus Torvalds's avatar
Linus Torvalds committed
1073 1074
{
	struct files_struct *files = current->files;
1075
	struct fdtable *fdt;
Linus Torvalds's avatar
Linus Torvalds committed
1076
	spin_lock(&files->file_lock);
1077
	fdt = files_fdtable(files);
1078 1079
	BUG_ON(fdt->fd[fd] != NULL);
	rcu_assign_pointer(fdt->fd[fd], file);
Linus Torvalds's avatar
Linus Torvalds committed
1080 1081 1082 1083 1084
	spin_unlock(&files->file_lock);
}

EXPORT_SYMBOL(fd_install);

1085
long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
Linus Torvalds's avatar
Linus Torvalds committed
1086
{
1087 1088
	char *tmp = getname(filename);
	int fd = PTR_ERR(tmp);
Linus Torvalds's avatar
Linus Torvalds committed
1089 1090

	if (!IS_ERR(tmp)) {
Ulrich Drepper's avatar
Ulrich Drepper committed
1091
		fd = get_unused_fd_flags(flags);
Linus Torvalds's avatar
Linus Torvalds committed
1092
		if (fd >= 0) {
1093
			struct file *f = do_filp_open(dfd, tmp, flags, mode);
1094 1095 1096 1097
			if (IS_ERR(f)) {
				put_unused_fd(fd);
				fd = PTR_ERR(f);
			} else {
1098
				fsnotify_open(f->f_path.dentry);
1099 1100
				fd_install(fd, f);
			}
Linus Torvalds's avatar
Linus Torvalds committed
1101 1102 1103 1104 1105
		}
		putname(tmp);
	}
	return fd;
}
1106 1107 1108

asmlinkage long sys_open(const char __user *filename, int flags, int mode)
{
1109 1110
	long ret;

1111 1112 1113
	if (force_o_largefile())
		flags |= O_LARGEFILE;

1114 1115
	ret = do_sys_open(AT_FDCWD, filename, flags, mode);
	/* avoid REGPARM breakage on x86: */
1116
	asmlinkage_protect(3, ret, filename, flags, mode);
1117
	return ret;
1118
}
Linus Torvalds's avatar
Linus Torvalds committed
1119

1120 1121 1122
asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
			   int mode)
{
1123 1124
	long ret;

1125 1126 1127
	if (force_o_largefile())
		flags |= O_LARGEFILE;

1128 1129
	ret = do_sys_open(dfd, filename, flags, mode);
	/* avoid REGPARM breakage on x86: */
1130
	asmlinkage_protect(4, ret, dfd, filename, flags, mode);
1131
	return ret;
1132 1133
}

Linus Torvalds's avatar
Linus Torvalds committed
1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152
#ifndef __alpha__

/*
 * For backward compatibility?  Maybe this should be moved
 * into arch/i386 instead?
 */
asmlinkage long sys_creat(const char __user * pathname, int mode)
{
	return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
}

#endif

/*
 * "id" is the POSIX thread ID. We use the
 * files pointer for this..
 */
int filp_close(struct file *filp, fl_owner_t id)
{
1153
	int retval = 0;
Linus Torvalds's avatar
Linus Torvalds committed
1154 1155 1156

	if (!file_count(filp)) {
		printk(KERN_ERR "VFS: Close: file count is 0\n");
1157
		return 0;
Linus Torvalds's avatar
Linus Torvalds committed
1158 1159
	}

1160
	if (filp->f_op && filp->f_op->flush)
1161
		retval = filp->f_op->flush(filp, id);
Linus Torvalds's avatar
Linus Torvalds committed
1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179

	dnotify_flush(filp, id);
	locks_remove_posix(filp, id);
	fput(filp);
	return retval;
}

EXPORT_SYMBOL(filp_close);

/*
 * Careful here! We test whether the file pointer is NULL before
 * releasing the fd. This ensures that one clone task can't release
 * an fd while another clone is opening it.
 */
asmlinkage long sys_close(unsigned int fd)
{
	struct file * filp;
	struct files_struct *files = current->files;
1180
	struct fdtable *fdt;
1181
	int retval;
Linus Torvalds's avatar
Linus Torvalds committed
1182 1183

	spin_lock(&files->file_lock);
1184 1185
	fdt = files_fdtable(files);
	if (fd >= fdt->max_fds)
Linus Torvalds's avatar
Linus Torvalds committed
1186
		goto out_unlock;
1187
	filp = fdt->fd[fd];
Linus Torvalds's avatar
Linus Torvalds committed
1188 1189
	if (!filp)
		goto out_unlock;
1190
	rcu_assign_pointer(fdt->fd[fd], NULL);
1191
	FD_CLR(fd, fdt->close_on_exec);
Linus Torvalds's avatar
Linus Torvalds committed
1192 1193
	__put_unused_fd(files, fd);
	spin_unlock(&files->file_lock);
1194 1195 1196 1197 1198 1199 1200 1201 1202 1203
	retval = filp_close(filp, files);

	/* can't restart close syscall because file table entry was cleared */
	if (unlikely(retval == -ERESTARTSYS ||
		     retval == -ERESTARTNOINTR ||
		     retval == -ERESTARTNOHAND ||
		     retval == -ERESTART_RESTARTBLOCK))
		retval = -EINTR;

	return retval;
Linus Torvalds's avatar
Linus Torvalds committed
1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218

out_unlock:
	spin_unlock(&files->file_lock);
	return -EBADF;
}

EXPORT_SYMBOL(sys_close);

/*
 * This routine simulates a hangup on the tty, to arrange that users
 * are given clean terminals at login time.
 */
asmlinkage long sys_vhangup(void)
{
	if (capable(CAP_SYS_TTY_CONFIG)) {
1219
		/* XXX: this needs locking */
Linus Torvalds's avatar
Linus Torvalds committed
1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234
		tty_vhangup(current->signal->tty);
		return 0;
	}
	return -EPERM;
}

/*
 * Called when an inode is about to be open.
 * We use this to disallow opening large files on 32bit systems if
 * the caller didn't specify O_LARGEFILE.  On 64bit systems we force
 * on this flag in sys_open.
 */
int generic_file_open(struct inode * inode, struct file * filp)
{
	if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1235
		return -EOVERFLOW;
Linus Torvalds's avatar
Linus Torvalds committed
1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251
	return 0;
}

EXPORT_SYMBOL(generic_file_open);

/*
 * This is used by subsystems that don't want seekable
 * file descriptors
 */
int nonseekable_open(struct inode *inode, struct file *filp)
{
	filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
	return 0;
}

EXPORT_SYMBOL(nonseekable_open);