4 * Copyright (C) 1991, 1992 Linus Torvalds
7 #include <linux/string.h>
9 #include <linux/file.h>
10 #include <linux/fdtable.h>
11 #include <linux/fsnotify.h>
12 #include <linux/module.h>
13 #include <linux/tty.h>
14 #include <linux/namei.h>
15 #include <linux/backing-dev.h>
16 #include <linux/capability.h>
17 #include <linux/securebits.h>
18 #include <linux/security.h>
19 #include <linux/mount.h>
20 #include <linux/fcntl.h>
21 #include <linux/slab.h>
22 #include <asm/uaccess.h>
24 #include <linux/personality.h>
25 #include <linux/pagemap.h>
26 #include <linux/syscalls.h>
27 #include <linux/rcupdate.h>
28 #include <linux/audit.h>
29 #include <linux/falloc.h>
30 #include <linux/fs_struct.h>
31 #include <linux/ima.h>
32 #include <linux/dnotify.h>
33 #include <linux/compat.h>
37 int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
41 struct iattr newattrs;
43 /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */
47 newattrs.ia_size = length;
48 newattrs.ia_valid = ATTR_SIZE | time_attrs;
50 newattrs.ia_file = filp;
51 newattrs.ia_valid |= ATTR_FILE;
54 /* Remove suid/sgid on truncate too */
55 ret = should_remove_suid(dentry);
57 newattrs.ia_valid |= ret | ATTR_FORCE;
59 mutex_lock(&dentry->d_inode->i_mutex);
60 /* Note any delegations or leases have already been broken: */
61 ret = notify_change(dentry, &newattrs, NULL);
62 mutex_unlock(&dentry->d_inode->i_mutex);
66 long vfs_truncate(struct path *path, loff_t length)
71 inode = path->dentry->d_inode;
73 /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
74 if (S_ISDIR(inode->i_mode))
76 if (!S_ISREG(inode->i_mode))
79 error = mnt_want_write(path->mnt);
83 error = inode_permission(inode, MAY_WRITE);
85 goto mnt_drop_write_and_out;
89 goto mnt_drop_write_and_out;
91 error = get_write_access(inode);
93 goto mnt_drop_write_and_out;
96 * Make sure that there are no leases. get_write_access() protects
97 * against the truncate racing with a lease-granting setlease().
99 error = break_lease(inode, O_WRONLY);
101 goto put_write_and_out;
103 error = locks_verify_truncate(inode, NULL, length);
105 error = security_path_truncate(path);
107 error = do_truncate(path->dentry, length, 0, NULL);
110 put_write_access(inode);
111 mnt_drop_write_and_out:
112 mnt_drop_write(path->mnt);
116 EXPORT_SYMBOL_GPL(vfs_truncate);
118 static long do_sys_truncate(const char __user *pathname, loff_t length)
120 unsigned int lookup_flags = LOOKUP_FOLLOW;
124 if (length < 0) /* sorry, but loff_t says... */
128 error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
130 error = vfs_truncate(&path, length);
133 if (retry_estale(error, lookup_flags)) {
134 lookup_flags |= LOOKUP_REVAL;
140 SYSCALL_DEFINE2(truncate, const char __user *, path, long, length)
142 return do_sys_truncate(path, length);
146 COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length)
148 return do_sys_truncate(path, length);
152 static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
155 struct dentry *dentry;
167 /* explicitly opened as large or we are on 64-bit box */
168 if (f.file->f_flags & O_LARGEFILE)
171 dentry = f.file->f_path.dentry;
172 inode = dentry->d_inode;
174 if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE))
178 /* Cannot ftruncate over 2^31 bytes without large file support */
179 if (small && length > MAX_NON_LFS)
183 if (IS_APPEND(inode))
186 sb_start_write(inode->i_sb);
187 error = locks_verify_truncate(inode, f.file, length);
189 error = security_path_truncate(&f.file->f_path);
191 error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, f.file);
192 sb_end_write(inode->i_sb);
199 SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length)
201 return do_sys_ftruncate(fd, length, 1);
205 COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length)
207 return do_sys_ftruncate(fd, length, 1);
211 /* LFS versions of truncate are only needed on 32 bit machines */
212 #if BITS_PER_LONG == 32
213 SYSCALL_DEFINE2(truncate64, const char __user *, path, loff_t, length)
215 return do_sys_truncate(path, length);
218 SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length)
220 return do_sys_ftruncate(fd, length, 0);
222 #endif /* BITS_PER_LONG == 32 */
225 int do_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
227 struct inode *inode = file_inode(file);
230 if (offset < 0 || len <= 0)
233 /* Return error if mode is not supported */
234 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
237 /* Punch hole must have keep size set */
238 if ((mode & FALLOC_FL_PUNCH_HOLE) &&
239 !(mode & FALLOC_FL_KEEP_SIZE))
242 if (!(file->f_mode & FMODE_WRITE))
245 /* It's not possible punch hole on append only file */
246 if (mode & FALLOC_FL_PUNCH_HOLE && IS_APPEND(inode))
249 if (IS_IMMUTABLE(inode))
253 * Revalidate the write permissions, in case security policy has
254 * changed since the files were opened.
256 ret = security_file_permission(file, MAY_WRITE);
260 if (S_ISFIFO(inode->i_mode))
264 * Let individual file system decide if it supports preallocation
265 * for directories or not.
267 if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
270 /* Check for wrap through zero too */
271 if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
274 if (!file->f_op->fallocate)
277 sb_start_write(inode->i_sb);
278 ret = file->f_op->fallocate(file, mode, offset, len);
279 sb_end_write(inode->i_sb);
283 SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
285 struct fd f = fdget(fd);
289 error = do_fallocate(f.file, mode, offset, len);
296 * access() needs to use the real uid/gid, not the effective uid/gid.
297 * We do this by temporarily clearing all FS-related capabilities and
298 * switching the fsuid/fsgid around to the real ones.
300 SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
302 const struct cred *old_cred;
303 struct cred *override_cred;
307 unsigned int lookup_flags = LOOKUP_FOLLOW;
309 if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */
312 override_cred = prepare_creds();
316 override_cred->fsuid = override_cred->uid;
317 override_cred->fsgid = override_cred->gid;
319 if (!issecure(SECURE_NO_SETUID_FIXUP)) {
320 /* Clear the capabilities if we switch to a non-root user */
321 kuid_t root_uid = make_kuid(override_cred->user_ns, 0);
322 if (!uid_eq(override_cred->uid, root_uid))
323 cap_clear(override_cred->cap_effective);
325 override_cred->cap_effective =
326 override_cred->cap_permitted;
329 old_cred = override_creds(override_cred);
331 res = user_path_at(dfd, filename, lookup_flags, &path);
335 inode = path.dentry->d_inode;
337 if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) {
339 * MAY_EXEC on regular files is denied if the fs is mounted
340 * with the "noexec" flag.
343 if (path.mnt->mnt_flags & MNT_NOEXEC)
344 goto out_path_release;
347 res = inode_permission(inode, mode | MAY_ACCESS);
348 /* SuS v2 requires we report a read only fs too */
349 if (res || !(mode & S_IWOTH) || special_file(inode->i_mode))
350 goto out_path_release;
352 * This is a rare case where using __mnt_is_readonly()
353 * is OK without a mnt_want/drop_write() pair. Since
354 * no actual write to the fs is performed here, we do
355 * not need to telegraph to that to anyone.
357 * By doing this, we accept that this access is
358 * inherently racy and know that the fs may change
359 * state before we even see this result.
361 if (__mnt_is_readonly(path.mnt))
366 if (retry_estale(res, lookup_flags)) {
367 lookup_flags |= LOOKUP_REVAL;
371 revert_creds(old_cred);
372 put_cred(override_cred);
376 SYSCALL_DEFINE2(access, const char __user *, filename, int, mode)
378 return sys_faccessat(AT_FDCWD, filename, mode);
381 SYSCALL_DEFINE1(chdir, const char __user *, filename)
385 unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
387 error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
391 error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
395 set_fs_pwd(current->fs, &path);
399 if (retry_estale(error, lookup_flags)) {
400 lookup_flags |= LOOKUP_REVAL;
407 SYSCALL_DEFINE1(fchdir, unsigned int, fd)
409 struct fd f = fdget_raw(fd);
417 inode = file_inode(f.file);
420 if (!S_ISDIR(inode->i_mode))
423 error = inode_permission(inode, MAY_EXEC | MAY_CHDIR);
425 set_fs_pwd(current->fs, &f.file->f_path);
432 SYSCALL_DEFINE1(chroot, const char __user *, filename)
436 unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
438 error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
442 error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
447 if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT))
449 error = security_path_chroot(&path);
453 set_fs_root(current->fs, &path);
457 if (retry_estale(error, lookup_flags)) {
458 lookup_flags |= LOOKUP_REVAL;
465 static int chmod_common(struct path *path, umode_t mode)
467 struct inode *inode = path->dentry->d_inode;
468 struct inode *delegated_inode = NULL;
469 struct iattr newattrs;
472 error = mnt_want_write(path->mnt);
476 mutex_lock(&inode->i_mutex);
477 error = security_path_chmod(path, mode);
480 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
481 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
482 error = notify_change(path->dentry, &newattrs, &delegated_inode);
484 mutex_unlock(&inode->i_mutex);
485 if (delegated_inode) {
486 error = break_deleg_wait(&delegated_inode);
490 mnt_drop_write(path->mnt);
494 SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode)
496 struct fd f = fdget(fd);
500 audit_inode(NULL, f.file->f_path.dentry, 0);
501 err = chmod_common(&f.file->f_path, mode);
507 SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, umode_t, mode)
511 unsigned int lookup_flags = LOOKUP_FOLLOW;
513 error = user_path_at(dfd, filename, lookup_flags, &path);
515 error = chmod_common(&path, mode);
517 if (retry_estale(error, lookup_flags)) {
518 lookup_flags |= LOOKUP_REVAL;
525 SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode)
527 return sys_fchmodat(AT_FDCWD, filename, mode);
530 static int chown_common(struct path *path, uid_t user, gid_t group)
532 struct inode *inode = path->dentry->d_inode;
533 struct inode *delegated_inode = NULL;
535 struct iattr newattrs;
539 uid = make_kuid(current_user_ns(), user);
540 gid = make_kgid(current_user_ns(), group);
542 newattrs.ia_valid = ATTR_CTIME;
543 if (user != (uid_t) -1) {
546 newattrs.ia_valid |= ATTR_UID;
547 newattrs.ia_uid = uid;
549 if (group != (gid_t) -1) {
552 newattrs.ia_valid |= ATTR_GID;
553 newattrs.ia_gid = gid;
555 if (!S_ISDIR(inode->i_mode))
557 ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
559 mutex_lock(&inode->i_mutex);
560 error = security_path_chown(path, uid, gid);
562 error = notify_change(path->dentry, &newattrs, &delegated_inode);
563 mutex_unlock(&inode->i_mutex);
564 if (delegated_inode) {
565 error = break_deleg_wait(&delegated_inode);
572 SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user,
573 gid_t, group, int, flag)
579 if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
582 lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
583 if (flag & AT_EMPTY_PATH)
584 lookup_flags |= LOOKUP_EMPTY;
586 error = user_path_at(dfd, filename, lookup_flags, &path);
589 error = mnt_want_write(path.mnt);
592 error = chown_common(&path, user, group);
593 mnt_drop_write(path.mnt);
596 if (retry_estale(error, lookup_flags)) {
597 lookup_flags |= LOOKUP_REVAL;
604 SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group)
606 return sys_fchownat(AT_FDCWD, filename, user, group, 0);
609 SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group)
611 return sys_fchownat(AT_FDCWD, filename, user, group,
612 AT_SYMLINK_NOFOLLOW);
615 SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)
617 struct fd f = fdget(fd);
623 error = mnt_want_write_file(f.file);
626 audit_inode(NULL, f.file->f_path.dentry, 0);
627 error = chown_common(&f.file->f_path, user, group);
628 mnt_drop_write_file(f.file);
635 int open_check_o_direct(struct file *f)
637 /* NB: we're sure to have correct a_ops only after f_op->open */
638 if (f->f_flags & O_DIRECT) {
639 if (!f->f_mapping->a_ops ||
640 ((!f->f_mapping->a_ops->direct_IO) &&
641 (!f->f_mapping->a_ops->get_xip_mem))) {
648 static int do_dentry_open(struct file *f,
649 int (*open)(struct inode *, struct file *),
650 const struct cred *cred)
652 static const struct file_operations empty_fops = {};
656 f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK |
657 FMODE_PREAD | FMODE_PWRITE;
659 path_get(&f->f_path);
660 inode = f->f_inode = f->f_path.dentry->d_inode;
661 f->f_mapping = inode->i_mapping;
663 if (unlikely(f->f_flags & O_PATH)) {
664 f->f_mode = FMODE_PATH;
665 f->f_op = &empty_fops;
669 if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) {
670 error = get_write_access(inode);
673 error = __mnt_want_write(f->f_path.mnt);
674 if (unlikely(error)) {
675 put_write_access(inode);
678 f->f_mode |= FMODE_WRITER;
681 /* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */
682 if (S_ISREG(inode->i_mode))
683 f->f_mode |= FMODE_ATOMIC_POS;
685 f->f_op = fops_get(inode->i_fop);
686 if (unlikely(WARN_ON(!f->f_op))) {
691 error = security_file_open(f, cred);
695 error = break_lease(inode, f->f_flags);
700 open = f->f_op->open;
702 error = open(inode, f);
706 if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
707 i_readcount_inc(inode);
709 f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
711 file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
717 if (f->f_mode & FMODE_WRITER) {
718 put_write_access(inode);
719 __mnt_drop_write(f->f_path.mnt);
722 path_put(&f->f_path);
723 f->f_path.mnt = NULL;
724 f->f_path.dentry = NULL;
730 * finish_open - finish opening a file
731 * @file: file pointer
732 * @dentry: pointer to dentry
733 * @open: open callback
734 * @opened: state of open
736 * This can be used to finish opening a file passed to i_op->atomic_open().
738 * If the open callback is set to NULL, then the standard f_op->open()
739 * filesystem callback is substituted.
741 * NB: the dentry reference is _not_ consumed. If, for example, the dentry is
742 * the return value of d_splice_alias(), then the caller needs to perform dput()
743 * on it after finish_open().
745 * On successful return @file is a fully instantiated open file. After this, if
746 * an error occurs in ->atomic_open(), it needs to clean up with fput().
748 * Returns zero on success or -errno if the open failed.
750 int finish_open(struct file *file, struct dentry *dentry,
751 int (*open)(struct inode *, struct file *),
755 BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */
757 file->f_path.dentry = dentry;
758 error = do_dentry_open(file, open, current_cred());
760 *opened |= FILE_OPENED;
764 EXPORT_SYMBOL(finish_open);
767 * finish_no_open - finish ->atomic_open() without opening the file
769 * @file: file pointer
770 * @dentry: dentry or NULL (as returned from ->lookup())
772 * This can be used to set the result of a successful lookup in ->atomic_open().
774 * NB: unlike finish_open() this function does consume the dentry reference and
775 * the caller need not dput() it.
777 * Returns "1" which must be the return value of ->atomic_open() after having
778 * called this function.
780 int finish_no_open(struct file *file, struct dentry *dentry)
782 file->f_path.dentry = dentry;
785 EXPORT_SYMBOL(finish_no_open);
787 struct file *dentry_open(const struct path *path, int flags,
788 const struct cred *cred)
793 validate_creds(cred);
795 /* We must always pass in a valid mount pointer. */
798 f = get_empty_filp();
802 error = do_dentry_open(f, NULL, cred);
804 /* from now on we need fput() to dispose of f */
805 error = open_check_o_direct(f);
817 EXPORT_SYMBOL(dentry_open);
819 static inline int build_open_flags(int flags, umode_t mode, struct open_flags *op)
821 int lookup_flags = 0;
824 if (flags & (O_CREAT | __O_TMPFILE))
825 op->mode = (mode & S_IALLUGO) | S_IFREG;
829 /* Must never be set by userspace */
830 flags &= ~FMODE_NONOTIFY & ~O_CLOEXEC;
833 * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only
834 * check for O_DSYNC if the need any syncing at all we enforce it's
835 * always set instead of having to deal with possibly weird behaviour
836 * for malicious applications setting only __O_SYNC.
838 if (flags & __O_SYNC)
841 if (flags & __O_TMPFILE) {
842 if ((flags & O_TMPFILE_MASK) != O_TMPFILE)
844 acc_mode = MAY_OPEN | ACC_MODE(flags);
845 if (!(acc_mode & MAY_WRITE))
847 } else if (flags & O_PATH) {
849 * If we have O_PATH in the open flag. Then we
850 * cannot have anything other than the below set of flags
852 flags &= O_DIRECTORY | O_NOFOLLOW | O_PATH;
855 acc_mode = MAY_OPEN | ACC_MODE(flags);
858 op->open_flag = flags;
860 /* O_TRUNC implies we need access checks for write permissions */
862 acc_mode |= MAY_WRITE;
864 /* Allow the LSM permission hook to distinguish append
865 access from general write access. */
866 if (flags & O_APPEND)
867 acc_mode |= MAY_APPEND;
869 op->acc_mode = acc_mode;
871 op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN;
873 if (flags & O_CREAT) {
874 op->intent |= LOOKUP_CREATE;
876 op->intent |= LOOKUP_EXCL;
879 if (flags & O_DIRECTORY)
880 lookup_flags |= LOOKUP_DIRECTORY;
881 if (!(flags & O_NOFOLLOW))
882 lookup_flags |= LOOKUP_FOLLOW;
883 op->lookup_flags = lookup_flags;
888 * file_open_name - open file and return file pointer
890 * @name: struct filename containing path to open
891 * @flags: open flags as per the open(2) second argument
892 * @mode: mode for the new file if O_CREAT is set, else ignored
894 * This is the helper to open a file from kernelspace if you really
895 * have to. But in generally you should not do this, so please move
896 * along, nothing to see here..
898 struct file *file_open_name(struct filename *name, int flags, umode_t mode)
900 struct open_flags op;
901 int err = build_open_flags(flags, mode, &op);
902 return err ? ERR_PTR(err) : do_filp_open(AT_FDCWD, name, &op);
906 * filp_open - open file and return file pointer
908 * @filename: path to open
909 * @flags: open flags as per the open(2) second argument
910 * @mode: mode for the new file if O_CREAT is set, else ignored
912 * This is the helper to open a file from kernelspace if you really
913 * have to. But in generally you should not do this, so please move
914 * along, nothing to see here..
916 struct file *filp_open(const char *filename, int flags, umode_t mode)
918 struct filename name = {.name = filename};
919 return file_open_name(&name, flags, mode);
921 EXPORT_SYMBOL(filp_open);
923 struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt,
924 const char *filename, int flags)
926 struct open_flags op;
927 int err = build_open_flags(flags, 0, &op);
931 return ERR_PTR(-EINVAL);
932 if (!filename && (flags & O_DIRECTORY))
933 if (!dentry->d_inode->i_op->lookup)
934 return ERR_PTR(-ENOTDIR);
935 return do_file_open_root(dentry, mnt, filename, &op);
937 EXPORT_SYMBOL(file_open_root);
939 long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode)
941 struct open_flags op;
942 int fd = build_open_flags(flags, mode, &op);
943 struct filename *tmp;
948 tmp = getname(filename);
952 fd = get_unused_fd_flags(flags);
954 struct file *f = do_filp_open(dfd, tmp, &op);
967 SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode)
969 if (force_o_largefile())
970 flags |= O_LARGEFILE;
972 return do_sys_open(AT_FDCWD, filename, flags, mode);
975 SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags,
978 if (force_o_largefile())
979 flags |= O_LARGEFILE;
981 return do_sys_open(dfd, filename, flags, mode);
987 * For backward compatibility? Maybe this should be moved
988 * into arch/i386 instead?
990 SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode)
992 return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
998 * "id" is the POSIX thread ID. We use the
999 * files pointer for this..
1001 int filp_close(struct file *filp, fl_owner_t id)
1005 if (!file_count(filp)) {
1006 printk(KERN_ERR "VFS: Close: file count is 0\n");
1010 if (filp->f_op->flush)
1011 retval = filp->f_op->flush(filp, id);
1013 if (likely(!(filp->f_mode & FMODE_PATH))) {
1014 dnotify_flush(filp, id);
1015 locks_remove_posix(filp, id);
1021 EXPORT_SYMBOL(filp_close);
1024 * Careful here! We test whether the file pointer is NULL before
1025 * releasing the fd. This ensures that one clone task can't release
1026 * an fd while another clone is opening it.
1028 SYSCALL_DEFINE1(close, unsigned int, fd)
1030 int retval = __close_fd(current->files, fd);
1032 /* can't restart close syscall because file table entry was cleared */
1033 if (unlikely(retval == -ERESTARTSYS ||
1034 retval == -ERESTARTNOINTR ||
1035 retval == -ERESTARTNOHAND ||
1036 retval == -ERESTART_RESTARTBLOCK))
1041 EXPORT_SYMBOL(sys_close);
1044 * This routine simulates a hangup on the tty, to arrange that users
1045 * are given clean terminals at login time.
1047 SYSCALL_DEFINE0(vhangup)
1049 if (capable(CAP_SYS_TTY_CONFIG)) {
1057 * Called when an inode is about to be open.
1058 * We use this to disallow opening large files on 32bit systems if
1059 * the caller didn't specify O_LARGEFILE. On 64bit systems we force
1060 * on this flag in sys_open.
1062 int generic_file_open(struct inode * inode, struct file * filp)
1064 if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1069 EXPORT_SYMBOL(generic_file_open);
1072 * This is used by subsystems that don't want seekable
1073 * file descriptors. The function is not supposed to ever fail, the only
1074 * reason it returns an 'int' and not 'void' is so that it can be plugged
1075 * directly into file_operations structure.
1077 int nonseekable_open(struct inode *inode, struct file *filp)
1079 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1083 EXPORT_SYMBOL(nonseekable_open);