| 1 | /* |
| 2 | * linux/fs/open.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | #include <linux/string.h> |
| 8 | #include <linux/mm.h> |
| 9 | #include <linux/file.h> |
| 10 | #include <linux/fdtable.h> |
| 11 | #include <linux/quotaops.h> |
| 12 | #include <linux/fsnotify.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/tty.h> |
| 16 | #include <linux/namei.h> |
| 17 | #include <linux/backing-dev.h> |
| 18 | #include <linux/capability.h> |
| 19 | #include <linux/securebits.h> |
| 20 | #include <linux/security.h> |
| 21 | #include <linux/mount.h> |
| 22 | #include <linux/vfs.h> |
| 23 | #include <linux/fcntl.h> |
| 24 | #include <asm/uaccess.h> |
| 25 | #include <linux/fs.h> |
| 26 | #include <linux/personality.h> |
| 27 | #include <linux/pagemap.h> |
| 28 | #include <linux/syscalls.h> |
| 29 | #include <linux/rcupdate.h> |
| 30 | #include <linux/audit.h> |
| 31 | #include <linux/falloc.h> |
| 32 | #include <linux/fs_struct.h> |
| 33 | |
| 34 | #include "internal.h" |
| 35 | |
| 36 | int vfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
| 37 | { |
| 38 | int retval = -ENODEV; |
| 39 | |
| 40 | if (dentry) { |
| 41 | retval = -ENOSYS; |
| 42 | if (dentry->d_sb->s_op->statfs) { |
| 43 | memset(buf, 0, sizeof(*buf)); |
| 44 | retval = security_sb_statfs(dentry); |
| 45 | if (retval) |
| 46 | return retval; |
| 47 | retval = dentry->d_sb->s_op->statfs(dentry, buf); |
| 48 | if (retval == 0 && buf->f_frsize == 0) |
| 49 | buf->f_frsize = buf->f_bsize; |
| 50 | } |
| 51 | } |
| 52 | return retval; |
| 53 | } |
| 54 | |
| 55 | EXPORT_SYMBOL(vfs_statfs); |
| 56 | |
| 57 | static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf) |
| 58 | { |
| 59 | struct kstatfs st; |
| 60 | int retval; |
| 61 | |
| 62 | retval = vfs_statfs(dentry, &st); |
| 63 | if (retval) |
| 64 | return retval; |
| 65 | |
| 66 | if (sizeof(*buf) == sizeof(st)) |
| 67 | memcpy(buf, &st, sizeof(st)); |
| 68 | else { |
| 69 | if (sizeof buf->f_blocks == 4) { |
| 70 | if ((st.f_blocks | st.f_bfree | st.f_bavail | |
| 71 | st.f_bsize | st.f_frsize) & |
| 72 | 0xffffffff00000000ULL) |
| 73 | return -EOVERFLOW; |
| 74 | /* |
| 75 | * f_files and f_ffree may be -1; it's okay to stuff |
| 76 | * that into 32 bits |
| 77 | */ |
| 78 | if (st.f_files != -1 && |
| 79 | (st.f_files & 0xffffffff00000000ULL)) |
| 80 | return -EOVERFLOW; |
| 81 | if (st.f_ffree != -1 && |
| 82 | (st.f_ffree & 0xffffffff00000000ULL)) |
| 83 | return -EOVERFLOW; |
| 84 | } |
| 85 | |
| 86 | buf->f_type = st.f_type; |
| 87 | buf->f_bsize = st.f_bsize; |
| 88 | buf->f_blocks = st.f_blocks; |
| 89 | buf->f_bfree = st.f_bfree; |
| 90 | buf->f_bavail = st.f_bavail; |
| 91 | buf->f_files = st.f_files; |
| 92 | buf->f_ffree = st.f_ffree; |
| 93 | buf->f_fsid = st.f_fsid; |
| 94 | buf->f_namelen = st.f_namelen; |
| 95 | buf->f_frsize = st.f_frsize; |
| 96 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); |
| 97 | } |
| 98 | return 0; |
| 99 | } |
| 100 | |
| 101 | static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf) |
| 102 | { |
| 103 | struct kstatfs st; |
| 104 | int retval; |
| 105 | |
| 106 | retval = vfs_statfs(dentry, &st); |
| 107 | if (retval) |
| 108 | return retval; |
| 109 | |
| 110 | if (sizeof(*buf) == sizeof(st)) |
| 111 | memcpy(buf, &st, sizeof(st)); |
| 112 | else { |
| 113 | buf->f_type = st.f_type; |
| 114 | buf->f_bsize = st.f_bsize; |
| 115 | buf->f_blocks = st.f_blocks; |
| 116 | buf->f_bfree = st.f_bfree; |
| 117 | buf->f_bavail = st.f_bavail; |
| 118 | buf->f_files = st.f_files; |
| 119 | buf->f_ffree = st.f_ffree; |
| 120 | buf->f_fsid = st.f_fsid; |
| 121 | buf->f_namelen = st.f_namelen; |
| 122 | buf->f_frsize = st.f_frsize; |
| 123 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); |
| 124 | } |
| 125 | return 0; |
| 126 | } |
| 127 | |
| 128 | SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, buf) |
| 129 | { |
| 130 | struct path path; |
| 131 | int error; |
| 132 | |
| 133 | error = user_path(pathname, &path); |
| 134 | if (!error) { |
| 135 | struct statfs tmp; |
| 136 | error = vfs_statfs_native(path.dentry, &tmp); |
| 137 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
| 138 | error = -EFAULT; |
| 139 | path_put(&path); |
| 140 | } |
| 141 | return error; |
| 142 | } |
| 143 | |
| 144 | SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct statfs64 __user *, buf) |
| 145 | { |
| 146 | struct path path; |
| 147 | long error; |
| 148 | |
| 149 | if (sz != sizeof(*buf)) |
| 150 | return -EINVAL; |
| 151 | error = user_path(pathname, &path); |
| 152 | if (!error) { |
| 153 | struct statfs64 tmp; |
| 154 | error = vfs_statfs64(path.dentry, &tmp); |
| 155 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
| 156 | error = -EFAULT; |
| 157 | path_put(&path); |
| 158 | } |
| 159 | return error; |
| 160 | } |
| 161 | |
| 162 | SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf) |
| 163 | { |
| 164 | struct file * file; |
| 165 | struct statfs tmp; |
| 166 | int error; |
| 167 | |
| 168 | error = -EBADF; |
| 169 | file = fget(fd); |
| 170 | if (!file) |
| 171 | goto out; |
| 172 | error = vfs_statfs_native(file->f_path.dentry, &tmp); |
| 173 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
| 174 | error = -EFAULT; |
| 175 | fput(file); |
| 176 | out: |
| 177 | return error; |
| 178 | } |
| 179 | |
| 180 | SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf) |
| 181 | { |
| 182 | struct file * file; |
| 183 | struct statfs64 tmp; |
| 184 | int error; |
| 185 | |
| 186 | if (sz != sizeof(*buf)) |
| 187 | return -EINVAL; |
| 188 | |
| 189 | error = -EBADF; |
| 190 | file = fget(fd); |
| 191 | if (!file) |
| 192 | goto out; |
| 193 | error = vfs_statfs64(file->f_path.dentry, &tmp); |
| 194 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
| 195 | error = -EFAULT; |
| 196 | fput(file); |
| 197 | out: |
| 198 | return error; |
| 199 | } |
| 200 | |
| 201 | int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, |
| 202 | struct file *filp) |
| 203 | { |
| 204 | int ret; |
| 205 | struct iattr newattrs; |
| 206 | |
| 207 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ |
| 208 | if (length < 0) |
| 209 | return -EINVAL; |
| 210 | |
| 211 | newattrs.ia_size = length; |
| 212 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
| 213 | if (filp) { |
| 214 | newattrs.ia_file = filp; |
| 215 | newattrs.ia_valid |= ATTR_FILE; |
| 216 | } |
| 217 | |
| 218 | /* Remove suid/sgid on truncate too */ |
| 219 | ret = should_remove_suid(dentry); |
| 220 | if (ret) |
| 221 | newattrs.ia_valid |= ret | ATTR_FORCE; |
| 222 | |
| 223 | mutex_lock(&dentry->d_inode->i_mutex); |
| 224 | ret = notify_change(dentry, &newattrs); |
| 225 | mutex_unlock(&dentry->d_inode->i_mutex); |
| 226 | return ret; |
| 227 | } |
| 228 | |
| 229 | static long do_sys_truncate(const char __user *pathname, loff_t length) |
| 230 | { |
| 231 | struct path path; |
| 232 | struct inode *inode; |
| 233 | int error; |
| 234 | |
| 235 | error = -EINVAL; |
| 236 | if (length < 0) /* sorry, but loff_t says... */ |
| 237 | goto out; |
| 238 | |
| 239 | error = user_path(pathname, &path); |
| 240 | if (error) |
| 241 | goto out; |
| 242 | inode = path.dentry->d_inode; |
| 243 | |
| 244 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ |
| 245 | error = -EISDIR; |
| 246 | if (S_ISDIR(inode->i_mode)) |
| 247 | goto dput_and_out; |
| 248 | |
| 249 | error = -EINVAL; |
| 250 | if (!S_ISREG(inode->i_mode)) |
| 251 | goto dput_and_out; |
| 252 | |
| 253 | error = mnt_want_write(path.mnt); |
| 254 | if (error) |
| 255 | goto dput_and_out; |
| 256 | |
| 257 | error = inode_permission(inode, MAY_WRITE); |
| 258 | if (error) |
| 259 | goto mnt_drop_write_and_out; |
| 260 | |
| 261 | error = -EPERM; |
| 262 | if (IS_APPEND(inode)) |
| 263 | goto mnt_drop_write_and_out; |
| 264 | |
| 265 | error = get_write_access(inode); |
| 266 | if (error) |
| 267 | goto mnt_drop_write_and_out; |
| 268 | |
| 269 | /* |
| 270 | * Make sure that there are no leases. get_write_access() protects |
| 271 | * against the truncate racing with a lease-granting setlease(). |
| 272 | */ |
| 273 | error = break_lease(inode, FMODE_WRITE); |
| 274 | if (error) |
| 275 | goto put_write_and_out; |
| 276 | |
| 277 | error = locks_verify_truncate(inode, NULL, length); |
| 278 | if (!error) |
| 279 | error = security_path_truncate(&path, length, 0); |
| 280 | if (!error) { |
| 281 | vfs_dq_init(inode); |
| 282 | error = do_truncate(path.dentry, length, 0, NULL); |
| 283 | } |
| 284 | |
| 285 | put_write_and_out: |
| 286 | put_write_access(inode); |
| 287 | mnt_drop_write_and_out: |
| 288 | mnt_drop_write(path.mnt); |
| 289 | dput_and_out: |
| 290 | path_put(&path); |
| 291 | out: |
| 292 | return error; |
| 293 | } |
| 294 | |
| 295 | SYSCALL_DEFINE2(truncate, const char __user *, path, long, length) |
| 296 | { |
| 297 | return do_sys_truncate(path, length); |
| 298 | } |
| 299 | |
| 300 | static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
| 301 | { |
| 302 | struct inode * inode; |
| 303 | struct dentry *dentry; |
| 304 | struct file * file; |
| 305 | int error; |
| 306 | |
| 307 | error = -EINVAL; |
| 308 | if (length < 0) |
| 309 | goto out; |
| 310 | error = -EBADF; |
| 311 | file = fget(fd); |
| 312 | if (!file) |
| 313 | goto out; |
| 314 | |
| 315 | /* explicitly opened as large or we are on 64-bit box */ |
| 316 | if (file->f_flags & O_LARGEFILE) |
| 317 | small = 0; |
| 318 | |
| 319 | dentry = file->f_path.dentry; |
| 320 | inode = dentry->d_inode; |
| 321 | error = -EINVAL; |
| 322 | if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) |
| 323 | goto out_putf; |
| 324 | |
| 325 | error = -EINVAL; |
| 326 | /* Cannot ftruncate over 2^31 bytes without large file support */ |
| 327 | if (small && length > MAX_NON_LFS) |
| 328 | goto out_putf; |
| 329 | |
| 330 | error = -EPERM; |
| 331 | if (IS_APPEND(inode)) |
| 332 | goto out_putf; |
| 333 | |
| 334 | error = locks_verify_truncate(inode, file, length); |
| 335 | if (!error) |
| 336 | error = security_path_truncate(&file->f_path, length, |
| 337 | ATTR_MTIME|ATTR_CTIME); |
| 338 | if (!error) |
| 339 | error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file); |
| 340 | out_putf: |
| 341 | fput(file); |
| 342 | out: |
| 343 | return error; |
| 344 | } |
| 345 | |
| 346 | SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length) |
| 347 | { |
| 348 | long ret = do_sys_ftruncate(fd, length, 1); |
| 349 | /* avoid REGPARM breakage on x86: */ |
| 350 | asmlinkage_protect(2, ret, fd, length); |
| 351 | return ret; |
| 352 | } |
| 353 | |
| 354 | /* LFS versions of truncate are only needed on 32 bit machines */ |
| 355 | #if BITS_PER_LONG == 32 |
| 356 | SYSCALL_DEFINE(truncate64)(const char __user * path, loff_t length) |
| 357 | { |
| 358 | return do_sys_truncate(path, length); |
| 359 | } |
| 360 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
| 361 | asmlinkage long SyS_truncate64(long path, loff_t length) |
| 362 | { |
| 363 | return SYSC_truncate64((const char __user *) path, length); |
| 364 | } |
| 365 | SYSCALL_ALIAS(sys_truncate64, SyS_truncate64); |
| 366 | #endif |
| 367 | |
| 368 | SYSCALL_DEFINE(ftruncate64)(unsigned int fd, loff_t length) |
| 369 | { |
| 370 | long ret = do_sys_ftruncate(fd, length, 0); |
| 371 | /* avoid REGPARM breakage on x86: */ |
| 372 | asmlinkage_protect(2, ret, fd, length); |
| 373 | return ret; |
| 374 | } |
| 375 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
| 376 | asmlinkage long SyS_ftruncate64(long fd, loff_t length) |
| 377 | { |
| 378 | return SYSC_ftruncate64((unsigned int) fd, length); |
| 379 | } |
| 380 | SYSCALL_ALIAS(sys_ftruncate64, SyS_ftruncate64); |
| 381 | #endif |
| 382 | #endif /* BITS_PER_LONG == 32 */ |
| 383 | |
| 384 | |
| 385 | int do_fallocate(struct file *file, int mode, loff_t offset, loff_t len) |
| 386 | { |
| 387 | struct inode *inode = file->f_path.dentry->d_inode; |
| 388 | long ret; |
| 389 | |
| 390 | if (offset < 0 || len <= 0) |
| 391 | return -EINVAL; |
| 392 | |
| 393 | /* Return error if mode is not supported */ |
| 394 | if (mode && !(mode & FALLOC_FL_KEEP_SIZE)) |
| 395 | return -EOPNOTSUPP; |
| 396 | |
| 397 | if (!(file->f_mode & FMODE_WRITE)) |
| 398 | return -EBADF; |
| 399 | /* |
| 400 | * Revalidate the write permissions, in case security policy has |
| 401 | * changed since the files were opened. |
| 402 | */ |
| 403 | ret = security_file_permission(file, MAY_WRITE); |
| 404 | if (ret) |
| 405 | return ret; |
| 406 | |
| 407 | if (S_ISFIFO(inode->i_mode)) |
| 408 | return -ESPIPE; |
| 409 | |
| 410 | /* |
| 411 | * Let individual file system decide if it supports preallocation |
| 412 | * for directories or not. |
| 413 | */ |
| 414 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) |
| 415 | return -ENODEV; |
| 416 | |
| 417 | /* Check for wrap through zero too */ |
| 418 | if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) |
| 419 | return -EFBIG; |
| 420 | |
| 421 | if (!inode->i_op->fallocate) |
| 422 | return -EOPNOTSUPP; |
| 423 | |
| 424 | return inode->i_op->fallocate(inode, mode, offset, len); |
| 425 | } |
| 426 | |
| 427 | SYSCALL_DEFINE(fallocate)(int fd, int mode, loff_t offset, loff_t len) |
| 428 | { |
| 429 | struct file *file; |
| 430 | int error = -EBADF; |
| 431 | |
| 432 | file = fget(fd); |
| 433 | if (file) { |
| 434 | error = do_fallocate(file, mode, offset, len); |
| 435 | fput(file); |
| 436 | } |
| 437 | |
| 438 | return error; |
| 439 | } |
| 440 | |
| 441 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
| 442 | asmlinkage long SyS_fallocate(long fd, long mode, loff_t offset, loff_t len) |
| 443 | { |
| 444 | return SYSC_fallocate((int)fd, (int)mode, offset, len); |
| 445 | } |
| 446 | SYSCALL_ALIAS(sys_fallocate, SyS_fallocate); |
| 447 | #endif |
| 448 | |
| 449 | /* |
| 450 | * access() needs to use the real uid/gid, not the effective uid/gid. |
| 451 | * We do this by temporarily clearing all FS-related capabilities and |
| 452 | * switching the fsuid/fsgid around to the real ones. |
| 453 | */ |
| 454 | SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode) |
| 455 | { |
| 456 | const struct cred *old_cred; |
| 457 | struct cred *override_cred; |
| 458 | struct path path; |
| 459 | struct inode *inode; |
| 460 | int res; |
| 461 | |
| 462 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ |
| 463 | return -EINVAL; |
| 464 | |
| 465 | override_cred = prepare_creds(); |
| 466 | if (!override_cred) |
| 467 | return -ENOMEM; |
| 468 | |
| 469 | override_cred->fsuid = override_cred->uid; |
| 470 | override_cred->fsgid = override_cred->gid; |
| 471 | |
| 472 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
| 473 | /* Clear the capabilities if we switch to a non-root user */ |
| 474 | if (override_cred->uid) |
| 475 | cap_clear(override_cred->cap_effective); |
| 476 | else |
| 477 | override_cred->cap_effective = |
| 478 | override_cred->cap_permitted; |
| 479 | } |
| 480 | |
| 481 | old_cred = override_creds(override_cred); |
| 482 | |
| 483 | res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
| 484 | if (res) |
| 485 | goto out; |
| 486 | |
| 487 | inode = path.dentry->d_inode; |
| 488 | |
| 489 | if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { |
| 490 | /* |
| 491 | * MAY_EXEC on regular files is denied if the fs is mounted |
| 492 | * with the "noexec" flag. |
| 493 | */ |
| 494 | res = -EACCES; |
| 495 | if (path.mnt->mnt_flags & MNT_NOEXEC) |
| 496 | goto out_path_release; |
| 497 | } |
| 498 | |
| 499 | res = inode_permission(inode, mode | MAY_ACCESS); |
| 500 | /* SuS v2 requires we report a read only fs too */ |
| 501 | if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) |
| 502 | goto out_path_release; |
| 503 | /* |
| 504 | * This is a rare case where using __mnt_is_readonly() |
| 505 | * is OK without a mnt_want/drop_write() pair. Since |
| 506 | * no actual write to the fs is performed here, we do |
| 507 | * not need to telegraph to that to anyone. |
| 508 | * |
| 509 | * By doing this, we accept that this access is |
| 510 | * inherently racy and know that the fs may change |
| 511 | * state before we even see this result. |
| 512 | */ |
| 513 | if (__mnt_is_readonly(path.mnt)) |
| 514 | res = -EROFS; |
| 515 | |
| 516 | out_path_release: |
| 517 | path_put(&path); |
| 518 | out: |
| 519 | revert_creds(old_cred); |
| 520 | put_cred(override_cred); |
| 521 | return res; |
| 522 | } |
| 523 | |
| 524 | SYSCALL_DEFINE2(access, const char __user *, filename, int, mode) |
| 525 | { |
| 526 | return sys_faccessat(AT_FDCWD, filename, mode); |
| 527 | } |
| 528 | |
| 529 | SYSCALL_DEFINE1(chdir, const char __user *, filename) |
| 530 | { |
| 531 | struct path path; |
| 532 | int error; |
| 533 | |
| 534 | error = user_path_dir(filename, &path); |
| 535 | if (error) |
| 536 | goto out; |
| 537 | |
| 538 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS); |
| 539 | if (error) |
| 540 | goto dput_and_out; |
| 541 | |
| 542 | set_fs_pwd(current->fs, &path); |
| 543 | |
| 544 | dput_and_out: |
| 545 | path_put(&path); |
| 546 | out: |
| 547 | return error; |
| 548 | } |
| 549 | |
| 550 | SYSCALL_DEFINE1(fchdir, unsigned int, fd) |
| 551 | { |
| 552 | struct file *file; |
| 553 | struct inode *inode; |
| 554 | int error; |
| 555 | |
| 556 | error = -EBADF; |
| 557 | file = fget(fd); |
| 558 | if (!file) |
| 559 | goto out; |
| 560 | |
| 561 | inode = file->f_path.dentry->d_inode; |
| 562 | |
| 563 | error = -ENOTDIR; |
| 564 | if (!S_ISDIR(inode->i_mode)) |
| 565 | goto out_putf; |
| 566 | |
| 567 | error = inode_permission(inode, MAY_EXEC | MAY_ACCESS); |
| 568 | if (!error) |
| 569 | set_fs_pwd(current->fs, &file->f_path); |
| 570 | out_putf: |
| 571 | fput(file); |
| 572 | out: |
| 573 | return error; |
| 574 | } |
| 575 | |
| 576 | SYSCALL_DEFINE1(chroot, const char __user *, filename) |
| 577 | { |
| 578 | struct path path; |
| 579 | int error; |
| 580 | |
| 581 | error = user_path_dir(filename, &path); |
| 582 | if (error) |
| 583 | goto out; |
| 584 | |
| 585 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS); |
| 586 | if (error) |
| 587 | goto dput_and_out; |
| 588 | |
| 589 | error = -EPERM; |
| 590 | if (!capable(CAP_SYS_CHROOT)) |
| 591 | goto dput_and_out; |
| 592 | error = security_path_chroot(&path); |
| 593 | if (error) |
| 594 | goto dput_and_out; |
| 595 | |
| 596 | set_fs_root(current->fs, &path); |
| 597 | error = 0; |
| 598 | dput_and_out: |
| 599 | path_put(&path); |
| 600 | out: |
| 601 | return error; |
| 602 | } |
| 603 | |
| 604 | SYSCALL_DEFINE2(fchmod, unsigned int, fd, mode_t, mode) |
| 605 | { |
| 606 | struct inode * inode; |
| 607 | struct dentry * dentry; |
| 608 | struct file * file; |
| 609 | int err = -EBADF; |
| 610 | struct iattr newattrs; |
| 611 | |
| 612 | file = fget(fd); |
| 613 | if (!file) |
| 614 | goto out; |
| 615 | |
| 616 | dentry = file->f_path.dentry; |
| 617 | inode = dentry->d_inode; |
| 618 | |
| 619 | audit_inode(NULL, dentry); |
| 620 | |
| 621 | err = mnt_want_write_file(file); |
| 622 | if (err) |
| 623 | goto out_putf; |
| 624 | mutex_lock(&inode->i_mutex); |
| 625 | err = security_path_chmod(dentry, file->f_vfsmnt, mode); |
| 626 | if (err) |
| 627 | goto out_unlock; |
| 628 | if (mode == (mode_t) -1) |
| 629 | mode = inode->i_mode; |
| 630 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
| 631 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; |
| 632 | err = notify_change(dentry, &newattrs); |
| 633 | out_unlock: |
| 634 | mutex_unlock(&inode->i_mutex); |
| 635 | mnt_drop_write(file->f_path.mnt); |
| 636 | out_putf: |
| 637 | fput(file); |
| 638 | out: |
| 639 | return err; |
| 640 | } |
| 641 | |
| 642 | SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, mode_t, mode) |
| 643 | { |
| 644 | struct path path; |
| 645 | struct inode *inode; |
| 646 | int error; |
| 647 | struct iattr newattrs; |
| 648 | |
| 649 | error = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
| 650 | if (error) |
| 651 | goto out; |
| 652 | inode = path.dentry->d_inode; |
| 653 | |
| 654 | error = mnt_want_write(path.mnt); |
| 655 | if (error) |
| 656 | goto dput_and_out; |
| 657 | mutex_lock(&inode->i_mutex); |
| 658 | error = security_path_chmod(path.dentry, path.mnt, mode); |
| 659 | if (error) |
| 660 | goto out_unlock; |
| 661 | if (mode == (mode_t) -1) |
| 662 | mode = inode->i_mode; |
| 663 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
| 664 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; |
| 665 | error = notify_change(path.dentry, &newattrs); |
| 666 | out_unlock: |
| 667 | mutex_unlock(&inode->i_mutex); |
| 668 | mnt_drop_write(path.mnt); |
| 669 | dput_and_out: |
| 670 | path_put(&path); |
| 671 | out: |
| 672 | return error; |
| 673 | } |
| 674 | |
| 675 | SYSCALL_DEFINE2(chmod, const char __user *, filename, mode_t, mode) |
| 676 | { |
| 677 | return sys_fchmodat(AT_FDCWD, filename, mode); |
| 678 | } |
| 679 | |
| 680 | static int chown_common(struct path *path, uid_t user, gid_t group) |
| 681 | { |
| 682 | struct inode *inode = path->dentry->d_inode; |
| 683 | int error; |
| 684 | struct iattr newattrs; |
| 685 | |
| 686 | newattrs.ia_valid = ATTR_CTIME; |
| 687 | if (user != (uid_t) -1) { |
| 688 | newattrs.ia_valid |= ATTR_UID; |
| 689 | newattrs.ia_uid = user; |
| 690 | } |
| 691 | if (group != (gid_t) -1) { |
| 692 | newattrs.ia_valid |= ATTR_GID; |
| 693 | newattrs.ia_gid = group; |
| 694 | } |
| 695 | if (!S_ISDIR(inode->i_mode)) |
| 696 | newattrs.ia_valid |= |
| 697 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; |
| 698 | mutex_lock(&inode->i_mutex); |
| 699 | error = security_path_chown(path, user, group); |
| 700 | if (!error) |
| 701 | error = notify_change(path->dentry, &newattrs); |
| 702 | mutex_unlock(&inode->i_mutex); |
| 703 | |
| 704 | return error; |
| 705 | } |
| 706 | |
| 707 | SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) |
| 708 | { |
| 709 | struct path path; |
| 710 | int error; |
| 711 | |
| 712 | error = user_path(filename, &path); |
| 713 | if (error) |
| 714 | goto out; |
| 715 | error = mnt_want_write(path.mnt); |
| 716 | if (error) |
| 717 | goto out_release; |
| 718 | error = chown_common(&path, user, group); |
| 719 | mnt_drop_write(path.mnt); |
| 720 | out_release: |
| 721 | path_put(&path); |
| 722 | out: |
| 723 | return error; |
| 724 | } |
| 725 | |
| 726 | SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, |
| 727 | gid_t, group, int, flag) |
| 728 | { |
| 729 | struct path path; |
| 730 | int error = -EINVAL; |
| 731 | int follow; |
| 732 | |
| 733 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) |
| 734 | goto out; |
| 735 | |
| 736 | follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; |
| 737 | error = user_path_at(dfd, filename, follow, &path); |
| 738 | if (error) |
| 739 | goto out; |
| 740 | error = mnt_want_write(path.mnt); |
| 741 | if (error) |
| 742 | goto out_release; |
| 743 | error = chown_common(&path, user, group); |
| 744 | mnt_drop_write(path.mnt); |
| 745 | out_release: |
| 746 | path_put(&path); |
| 747 | out: |
| 748 | return error; |
| 749 | } |
| 750 | |
| 751 | SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) |
| 752 | { |
| 753 | struct path path; |
| 754 | int error; |
| 755 | |
| 756 | error = user_lpath(filename, &path); |
| 757 | if (error) |
| 758 | goto out; |
| 759 | error = mnt_want_write(path.mnt); |
| 760 | if (error) |
| 761 | goto out_release; |
| 762 | error = chown_common(&path, user, group); |
| 763 | mnt_drop_write(path.mnt); |
| 764 | out_release: |
| 765 | path_put(&path); |
| 766 | out: |
| 767 | return error; |
| 768 | } |
| 769 | |
| 770 | SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) |
| 771 | { |
| 772 | struct file * file; |
| 773 | int error = -EBADF; |
| 774 | struct dentry * dentry; |
| 775 | |
| 776 | file = fget(fd); |
| 777 | if (!file) |
| 778 | goto out; |
| 779 | |
| 780 | error = mnt_want_write_file(file); |
| 781 | if (error) |
| 782 | goto out_fput; |
| 783 | dentry = file->f_path.dentry; |
| 784 | audit_inode(NULL, dentry); |
| 785 | error = chown_common(&file->f_path, user, group); |
| 786 | mnt_drop_write(file->f_path.mnt); |
| 787 | out_fput: |
| 788 | fput(file); |
| 789 | out: |
| 790 | return error; |
| 791 | } |
| 792 | |
| 793 | /* |
| 794 | * You have to be very careful that these write |
| 795 | * counts get cleaned up in error cases and |
| 796 | * upon __fput(). This should probably never |
| 797 | * be called outside of __dentry_open(). |
| 798 | */ |
| 799 | static inline int __get_file_write_access(struct inode *inode, |
| 800 | struct vfsmount *mnt) |
| 801 | { |
| 802 | int error; |
| 803 | error = get_write_access(inode); |
| 804 | if (error) |
| 805 | return error; |
| 806 | /* |
| 807 | * Do not take mount writer counts on |
| 808 | * special files since no writes to |
| 809 | * the mount itself will occur. |
| 810 | */ |
| 811 | if (!special_file(inode->i_mode)) { |
| 812 | /* |
| 813 | * Balanced in __fput() |
| 814 | */ |
| 815 | error = mnt_want_write(mnt); |
| 816 | if (error) |
| 817 | put_write_access(inode); |
| 818 | } |
| 819 | return error; |
| 820 | } |
| 821 | |
| 822 | static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
| 823 | int flags, struct file *f, |
| 824 | int (*open)(struct inode *, struct file *), |
| 825 | const struct cred *cred) |
| 826 | { |
| 827 | struct inode *inode; |
| 828 | int error; |
| 829 | |
| 830 | f->f_flags = flags; |
| 831 | f->f_mode = (__force fmode_t)((flags+1) & O_ACCMODE) | FMODE_LSEEK | |
| 832 | FMODE_PREAD | FMODE_PWRITE; |
| 833 | inode = dentry->d_inode; |
| 834 | if (f->f_mode & FMODE_WRITE) { |
| 835 | error = __get_file_write_access(inode, mnt); |
| 836 | if (error) |
| 837 | goto cleanup_file; |
| 838 | if (!special_file(inode->i_mode)) |
| 839 | file_take_write(f); |
| 840 | } |
| 841 | |
| 842 | f->f_mapping = inode->i_mapping; |
| 843 | f->f_path.dentry = dentry; |
| 844 | f->f_path.mnt = mnt; |
| 845 | f->f_pos = 0; |
| 846 | f->f_op = fops_get(inode->i_fop); |
| 847 | file_move(f, &inode->i_sb->s_files); |
| 848 | |
| 849 | error = security_dentry_open(f, cred); |
| 850 | if (error) |
| 851 | goto cleanup_all; |
| 852 | |
| 853 | if (!open && f->f_op) |
| 854 | open = f->f_op->open; |
| 855 | if (open) { |
| 856 | error = open(inode, f); |
| 857 | if (error) |
| 858 | goto cleanup_all; |
| 859 | } |
| 860 | |
| 861 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
| 862 | |
| 863 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); |
| 864 | |
| 865 | /* NB: we're sure to have correct a_ops only after f_op->open */ |
| 866 | if (f->f_flags & O_DIRECT) { |
| 867 | if (!f->f_mapping->a_ops || |
| 868 | ((!f->f_mapping->a_ops->direct_IO) && |
| 869 | (!f->f_mapping->a_ops->get_xip_mem))) { |
| 870 | fput(f); |
| 871 | f = ERR_PTR(-EINVAL); |
| 872 | } |
| 873 | } |
| 874 | |
| 875 | return f; |
| 876 | |
| 877 | cleanup_all: |
| 878 | fops_put(f->f_op); |
| 879 | if (f->f_mode & FMODE_WRITE) { |
| 880 | put_write_access(inode); |
| 881 | if (!special_file(inode->i_mode)) { |
| 882 | /* |
| 883 | * We don't consider this a real |
| 884 | * mnt_want/drop_write() pair |
| 885 | * because it all happenend right |
| 886 | * here, so just reset the state. |
| 887 | */ |
| 888 | file_reset_write(f); |
| 889 | mnt_drop_write(mnt); |
| 890 | } |
| 891 | } |
| 892 | file_kill(f); |
| 893 | f->f_path.dentry = NULL; |
| 894 | f->f_path.mnt = NULL; |
| 895 | cleanup_file: |
| 896 | put_filp(f); |
| 897 | dput(dentry); |
| 898 | mntput(mnt); |
| 899 | return ERR_PTR(error); |
| 900 | } |
| 901 | |
| 902 | /** |
| 903 | * lookup_instantiate_filp - instantiates the open intent filp |
| 904 | * @nd: pointer to nameidata |
| 905 | * @dentry: pointer to dentry |
| 906 | * @open: open callback |
| 907 | * |
| 908 | * Helper for filesystems that want to use lookup open intents and pass back |
| 909 | * a fully instantiated struct file to the caller. |
| 910 | * This function is meant to be called from within a filesystem's |
| 911 | * lookup method. |
| 912 | * Beware of calling it for non-regular files! Those ->open methods might block |
| 913 | * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, |
| 914 | * leading to a deadlock, as nobody can open that fifo anymore, because |
| 915 | * another process to open fifo will block on locked parent when doing lookup). |
| 916 | * Note that in case of error, nd->intent.open.file is destroyed, but the |
| 917 | * path information remains valid. |
| 918 | * If the open callback is set to NULL, then the standard f_op->open() |
| 919 | * filesystem callback is substituted. |
| 920 | */ |
| 921 | struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, |
| 922 | int (*open)(struct inode *, struct file *)) |
| 923 | { |
| 924 | const struct cred *cred = current_cred(); |
| 925 | |
| 926 | if (IS_ERR(nd->intent.open.file)) |
| 927 | goto out; |
| 928 | if (IS_ERR(dentry)) |
| 929 | goto out_err; |
| 930 | nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt), |
| 931 | nd->intent.open.flags - 1, |
| 932 | nd->intent.open.file, |
| 933 | open, cred); |
| 934 | out: |
| 935 | return nd->intent.open.file; |
| 936 | out_err: |
| 937 | release_open_intent(nd); |
| 938 | nd->intent.open.file = (struct file *)dentry; |
| 939 | goto out; |
| 940 | } |
| 941 | EXPORT_SYMBOL_GPL(lookup_instantiate_filp); |
| 942 | |
| 943 | /** |
| 944 | * nameidata_to_filp - convert a nameidata to an open filp. |
| 945 | * @nd: pointer to nameidata |
| 946 | * @flags: open flags |
| 947 | * |
| 948 | * Note that this function destroys the original nameidata |
| 949 | */ |
| 950 | struct file *nameidata_to_filp(struct nameidata *nd, int flags) |
| 951 | { |
| 952 | const struct cred *cred = current_cred(); |
| 953 | struct file *filp; |
| 954 | |
| 955 | /* Pick up the filp from the open intent */ |
| 956 | filp = nd->intent.open.file; |
| 957 | /* Has the filesystem initialised the file for us? */ |
| 958 | if (filp->f_path.dentry == NULL) |
| 959 | filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp, |
| 960 | NULL, cred); |
| 961 | else |
| 962 | path_put(&nd->path); |
| 963 | return filp; |
| 964 | } |
| 965 | |
| 966 | /* |
| 967 | * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an |
| 968 | * error. |
| 969 | */ |
| 970 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, |
| 971 | const struct cred *cred) |
| 972 | { |
| 973 | int error; |
| 974 | struct file *f; |
| 975 | |
| 976 | validate_creds(cred); |
| 977 | |
| 978 | /* |
| 979 | * We must always pass in a valid mount pointer. Historically |
| 980 | * callers got away with not passing it, but we must enforce this at |
| 981 | * the earliest possible point now to avoid strange problems deep in the |
| 982 | * filesystem stack. |
| 983 | */ |
| 984 | if (!mnt) { |
| 985 | printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__); |
| 986 | dump_stack(); |
| 987 | return ERR_PTR(-EINVAL); |
| 988 | } |
| 989 | |
| 990 | error = -ENFILE; |
| 991 | f = get_empty_filp(); |
| 992 | if (f == NULL) { |
| 993 | dput(dentry); |
| 994 | mntput(mnt); |
| 995 | return ERR_PTR(error); |
| 996 | } |
| 997 | |
| 998 | return __dentry_open(dentry, mnt, flags, f, NULL, cred); |
| 999 | } |
| 1000 | EXPORT_SYMBOL(dentry_open); |
| 1001 | |
| 1002 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
| 1003 | { |
| 1004 | struct fdtable *fdt = files_fdtable(files); |
| 1005 | __FD_CLR(fd, fdt->open_fds); |
| 1006 | if (fd < files->next_fd) |
| 1007 | files->next_fd = fd; |
| 1008 | } |
| 1009 | |
| 1010 | void put_unused_fd(unsigned int fd) |
| 1011 | { |
| 1012 | struct files_struct *files = current->files; |
| 1013 | spin_lock(&files->file_lock); |
| 1014 | __put_unused_fd(files, fd); |
| 1015 | spin_unlock(&files->file_lock); |
| 1016 | } |
| 1017 | |
| 1018 | EXPORT_SYMBOL(put_unused_fd); |
| 1019 | |
| 1020 | /* |
| 1021 | * Install a file pointer in the fd array. |
| 1022 | * |
| 1023 | * The VFS is full of places where we drop the files lock between |
| 1024 | * setting the open_fds bitmap and installing the file in the file |
| 1025 | * array. At any such point, we are vulnerable to a dup2() race |
| 1026 | * installing a file in the array before us. We need to detect this and |
| 1027 | * fput() the struct file we are about to overwrite in this case. |
| 1028 | * |
| 1029 | * It should never happen - if we allow dup2() do it, _really_ bad things |
| 1030 | * will follow. |
| 1031 | */ |
| 1032 | |
| 1033 | void fd_install(unsigned int fd, struct file *file) |
| 1034 | { |
| 1035 | struct files_struct *files = current->files; |
| 1036 | struct fdtable *fdt; |
| 1037 | spin_lock(&files->file_lock); |
| 1038 | fdt = files_fdtable(files); |
| 1039 | BUG_ON(fdt->fd[fd] != NULL); |
| 1040 | rcu_assign_pointer(fdt->fd[fd], file); |
| 1041 | spin_unlock(&files->file_lock); |
| 1042 | } |
| 1043 | |
| 1044 | EXPORT_SYMBOL(fd_install); |
| 1045 | |
| 1046 | long do_sys_open(int dfd, const char __user *filename, int flags, int mode) |
| 1047 | { |
| 1048 | char *tmp = getname(filename); |
| 1049 | int fd = PTR_ERR(tmp); |
| 1050 | |
| 1051 | if (!IS_ERR(tmp)) { |
| 1052 | fd = get_unused_fd_flags(flags); |
| 1053 | if (fd >= 0) { |
| 1054 | struct file *f = do_filp_open(dfd, tmp, flags, mode, 0); |
| 1055 | if (IS_ERR(f)) { |
| 1056 | put_unused_fd(fd); |
| 1057 | fd = PTR_ERR(f); |
| 1058 | } else { |
| 1059 | fsnotify_open(f->f_path.dentry); |
| 1060 | fd_install(fd, f); |
| 1061 | } |
| 1062 | } |
| 1063 | putname(tmp); |
| 1064 | } |
| 1065 | return fd; |
| 1066 | } |
| 1067 | |
| 1068 | SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, int, mode) |
| 1069 | { |
| 1070 | long ret; |
| 1071 | |
| 1072 | if (force_o_largefile()) |
| 1073 | flags |= O_LARGEFILE; |
| 1074 | |
| 1075 | ret = do_sys_open(AT_FDCWD, filename, flags, mode); |
| 1076 | /* avoid REGPARM breakage on x86: */ |
| 1077 | asmlinkage_protect(3, ret, filename, flags, mode); |
| 1078 | return ret; |
| 1079 | } |
| 1080 | |
| 1081 | SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, |
| 1082 | int, mode) |
| 1083 | { |
| 1084 | long ret; |
| 1085 | |
| 1086 | if (force_o_largefile()) |
| 1087 | flags |= O_LARGEFILE; |
| 1088 | |
| 1089 | ret = do_sys_open(dfd, filename, flags, mode); |
| 1090 | /* avoid REGPARM breakage on x86: */ |
| 1091 | asmlinkage_protect(4, ret, dfd, filename, flags, mode); |
| 1092 | return ret; |
| 1093 | } |
| 1094 | |
| 1095 | #ifndef __alpha__ |
| 1096 | |
| 1097 | /* |
| 1098 | * For backward compatibility? Maybe this should be moved |
| 1099 | * into arch/i386 instead? |
| 1100 | */ |
| 1101 | SYSCALL_DEFINE2(creat, const char __user *, pathname, int, mode) |
| 1102 | { |
| 1103 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); |
| 1104 | } |
| 1105 | |
| 1106 | #endif |
| 1107 | |
| 1108 | /* |
| 1109 | * "id" is the POSIX thread ID. We use the |
| 1110 | * files pointer for this.. |
| 1111 | */ |
| 1112 | int filp_close(struct file *filp, fl_owner_t id) |
| 1113 | { |
| 1114 | int retval = 0; |
| 1115 | |
| 1116 | if (!file_count(filp)) { |
| 1117 | printk(KERN_ERR "VFS: Close: file count is 0\n"); |
| 1118 | return 0; |
| 1119 | } |
| 1120 | |
| 1121 | if (filp->f_op && filp->f_op->flush) |
| 1122 | retval = filp->f_op->flush(filp, id); |
| 1123 | |
| 1124 | dnotify_flush(filp, id); |
| 1125 | locks_remove_posix(filp, id); |
| 1126 | fput(filp); |
| 1127 | return retval; |
| 1128 | } |
| 1129 | |
| 1130 | EXPORT_SYMBOL(filp_close); |
| 1131 | |
| 1132 | /* |
| 1133 | * Careful here! We test whether the file pointer is NULL before |
| 1134 | * releasing the fd. This ensures that one clone task can't release |
| 1135 | * an fd while another clone is opening it. |
| 1136 | */ |
| 1137 | SYSCALL_DEFINE1(close, unsigned int, fd) |
| 1138 | { |
| 1139 | struct file * filp; |
| 1140 | struct files_struct *files = current->files; |
| 1141 | struct fdtable *fdt; |
| 1142 | int retval; |
| 1143 | |
| 1144 | spin_lock(&files->file_lock); |
| 1145 | fdt = files_fdtable(files); |
| 1146 | if (fd >= fdt->max_fds) |
| 1147 | goto out_unlock; |
| 1148 | filp = fdt->fd[fd]; |
| 1149 | if (!filp) |
| 1150 | goto out_unlock; |
| 1151 | rcu_assign_pointer(fdt->fd[fd], NULL); |
| 1152 | FD_CLR(fd, fdt->close_on_exec); |
| 1153 | __put_unused_fd(files, fd); |
| 1154 | spin_unlock(&files->file_lock); |
| 1155 | retval = filp_close(filp, files); |
| 1156 | |
| 1157 | /* can't restart close syscall because file table entry was cleared */ |
| 1158 | if (unlikely(retval == -ERESTARTSYS || |
| 1159 | retval == -ERESTARTNOINTR || |
| 1160 | retval == -ERESTARTNOHAND || |
| 1161 | retval == -ERESTART_RESTARTBLOCK)) |
| 1162 | retval = -EINTR; |
| 1163 | |
| 1164 | return retval; |
| 1165 | |
| 1166 | out_unlock: |
| 1167 | spin_unlock(&files->file_lock); |
| 1168 | return -EBADF; |
| 1169 | } |
| 1170 | EXPORT_SYMBOL(sys_close); |
| 1171 | |
| 1172 | /* |
| 1173 | * This routine simulates a hangup on the tty, to arrange that users |
| 1174 | * are given clean terminals at login time. |
| 1175 | */ |
| 1176 | SYSCALL_DEFINE0(vhangup) |
| 1177 | { |
| 1178 | if (capable(CAP_SYS_TTY_CONFIG)) { |
| 1179 | tty_vhangup_self(); |
| 1180 | return 0; |
| 1181 | } |
| 1182 | return -EPERM; |
| 1183 | } |
| 1184 | |
| 1185 | /* |
| 1186 | * Called when an inode is about to be open. |
| 1187 | * We use this to disallow opening large files on 32bit systems if |
| 1188 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force |
| 1189 | * on this flag in sys_open. |
| 1190 | */ |
| 1191 | int generic_file_open(struct inode * inode, struct file * filp) |
| 1192 | { |
| 1193 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) |
| 1194 | return -EOVERFLOW; |
| 1195 | return 0; |
| 1196 | } |
| 1197 | |
| 1198 | EXPORT_SYMBOL(generic_file_open); |
| 1199 | |
| 1200 | /* |
| 1201 | * This is used by subsystems that don't want seekable |
| 1202 | * file descriptors |
| 1203 | */ |
| 1204 | int nonseekable_open(struct inode *inode, struct file *filp) |
| 1205 | { |
| 1206 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); |
| 1207 | return 0; |
| 1208 | } |
| 1209 | |
| 1210 | EXPORT_SYMBOL(nonseekable_open); |