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/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>
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>
36 int vfs_statfs(struct dentry *dentry, struct kstatfs *buf)
42 if (dentry->d_sb->s_op->statfs) {
43 memset(buf, 0, sizeof(*buf));
44 retval = security_sb_statfs(dentry);
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;
55 EXPORT_SYMBOL(vfs_statfs);
57 static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf)
62 retval = vfs_statfs(dentry, &st);
66 if (sizeof(*buf) == sizeof(st))
67 memcpy(buf, &st, sizeof(st));
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)
75 * f_files and f_ffree may be -1; it's okay to stuff
78 if (st.f_files != -1 &&
79 (st.f_files & 0xffffffff00000000ULL))
81 if (st.f_ffree != -1 &&
82 (st.f_ffree & 0xffffffff00000000ULL))
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));
101 static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf)
106 retval = vfs_statfs(dentry, &st);
110 if (sizeof(*buf) == sizeof(st))
111 memcpy(buf, &st, sizeof(st));
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));
128 SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, buf)
133 error = user_path(pathname, &path);
136 error = vfs_statfs_native(path.dentry, &tmp);
137 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
144 SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct statfs64 __user *, buf)
149 if (sz != sizeof(*buf))
151 error = user_path(pathname, &path);
154 error = vfs_statfs64(path.dentry, &tmp);
155 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
162 SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf)
172 error = vfs_statfs_native(file->f_path.dentry, &tmp);
173 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
180 SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf)
186 if (sz != sizeof(*buf))
193 error = vfs_statfs64(file->f_path.dentry, &tmp);
194 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
201 int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
205 struct iattr newattrs;
207 /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */
211 newattrs.ia_size = length;
212 newattrs.ia_valid = ATTR_SIZE | time_attrs;
214 newattrs.ia_file = filp;
215 newattrs.ia_valid |= ATTR_FILE;
218 /* Remove suid/sgid on truncate too */
219 ret = should_remove_suid(dentry);
221 newattrs.ia_valid |= ret | ATTR_FORCE;
223 mutex_lock(&dentry->d_inode->i_mutex);
224 ret = notify_change(dentry, &newattrs);
225 mutex_unlock(&dentry->d_inode->i_mutex);
229 static long do_sys_truncate(const char __user *pathname, loff_t length)
236 if (length < 0) /* sorry, but loff_t says... */
239 error = user_path(pathname, &path);
242 inode = path.dentry->d_inode;
244 /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
246 if (S_ISDIR(inode->i_mode))
250 if (!S_ISREG(inode->i_mode))
253 error = mnt_want_write(path.mnt);
257 error = inode_permission(inode, MAY_WRITE);
259 goto mnt_drop_write_and_out;
262 if (IS_APPEND(inode))
263 goto mnt_drop_write_and_out;
265 error = get_write_access(inode);
267 goto mnt_drop_write_and_out;
270 * Make sure that there are no leases. get_write_access() protects
271 * against the truncate racing with a lease-granting setlease().
273 error = break_lease(inode, FMODE_WRITE);
275 goto put_write_and_out;
277 error = locks_verify_truncate(inode, NULL, length);
279 error = security_path_truncate(&path, length, 0);
282 error = do_truncate(path.dentry, length, 0, NULL);
286 put_write_access(inode);
287 mnt_drop_write_and_out:
288 mnt_drop_write(path.mnt);
295 SYSCALL_DEFINE2(truncate, const char __user *, path, long, length)
297 return do_sys_truncate(path, length);
300 static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
302 struct inode * inode;
303 struct dentry *dentry;
315 /* explicitly opened as large or we are on 64-bit box */
316 if (file->f_flags & O_LARGEFILE)
319 dentry = file->f_path.dentry;
320 inode = dentry->d_inode;
322 if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
326 /* Cannot ftruncate over 2^31 bytes without large file support */
327 if (small && length > MAX_NON_LFS)
331 if (IS_APPEND(inode))
334 error = locks_verify_truncate(inode, file, length);
336 error = security_path_truncate(&file->f_path, length,
337 ATTR_MTIME|ATTR_CTIME);
339 error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file);
346 SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length)
348 long ret = do_sys_ftruncate(fd, length, 1);
349 /* avoid REGPARM breakage on x86: */
350 asmlinkage_protect(2, ret, fd, length);
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)
358 return do_sys_truncate(path, length);
360 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
361 asmlinkage long SyS_truncate64(long path, loff_t length)
363 return SYSC_truncate64((const char __user *) path, length);
365 SYSCALL_ALIAS(sys_truncate64, SyS_truncate64);
368 SYSCALL_DEFINE(ftruncate64)(unsigned int fd, loff_t length)
370 long ret = do_sys_ftruncate(fd, length, 0);
371 /* avoid REGPARM breakage on x86: */
372 asmlinkage_protect(2, ret, fd, length);
375 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
376 asmlinkage long SyS_ftruncate64(long fd, loff_t length)
378 return SYSC_ftruncate64((unsigned int) fd, length);
380 SYSCALL_ALIAS(sys_ftruncate64, SyS_ftruncate64);
382 #endif /* BITS_PER_LONG == 32 */
385 int do_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
387 struct inode *inode = file->f_path.dentry->d_inode;
390 if (offset < 0 || len <= 0)
393 /* Return error if mode is not supported */
394 if (mode && !(mode & FALLOC_FL_KEEP_SIZE))
397 if (!(file->f_mode & FMODE_WRITE))
400 * Revalidate the write permissions, in case security policy has
401 * changed since the files were opened.
403 ret = security_file_permission(file, MAY_WRITE);
407 if (S_ISFIFO(inode->i_mode))
411 * Let individual file system decide if it supports preallocation
412 * for directories or not.
414 if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
417 /* Check for wrap through zero too */
418 if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
421 if (!inode->i_op->fallocate)
424 return inode->i_op->fallocate(inode, mode, offset, len);
427 SYSCALL_DEFINE(fallocate)(int fd, int mode, loff_t offset, loff_t len)
434 error = do_fallocate(file, mode, offset, len);
441 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
442 asmlinkage long SyS_fallocate(long fd, long mode, loff_t offset, loff_t len)
444 return SYSC_fallocate((int)fd, (int)mode, offset, len);
446 SYSCALL_ALIAS(sys_fallocate, SyS_fallocate);
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.
454 SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
456 const struct cred *old_cred;
457 struct cred *override_cred;
462 if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */
465 override_cred = prepare_creds();
469 override_cred->fsuid = override_cred->uid;
470 override_cred->fsgid = override_cred->gid;
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);
477 override_cred->cap_effective =
478 override_cred->cap_permitted;
481 old_cred = override_creds(override_cred);
483 res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path);
487 inode = path.dentry->d_inode;
489 if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) {
491 * MAY_EXEC on regular files is denied if the fs is mounted
492 * with the "noexec" flag.
495 if (path.mnt->mnt_flags & MNT_NOEXEC)
496 goto out_path_release;
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;
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.
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.
513 if (__mnt_is_readonly(path.mnt))
519 revert_creds(old_cred);
520 put_cred(override_cred);
524 SYSCALL_DEFINE2(access, const char __user *, filename, int, mode)
526 return sys_faccessat(AT_FDCWD, filename, mode);
529 SYSCALL_DEFINE1(chdir, const char __user *, filename)
534 error = user_path_dir(filename, &path);
538 error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS);
542 set_fs_pwd(current->fs, &path);
550 SYSCALL_DEFINE1(fchdir, unsigned int, fd)
561 inode = file->f_path.dentry->d_inode;
564 if (!S_ISDIR(inode->i_mode))
567 error = inode_permission(inode, MAY_EXEC | MAY_ACCESS);
569 set_fs_pwd(current->fs, &file->f_path);
576 SYSCALL_DEFINE1(chroot, const char __user *, filename)
581 error = user_path_dir(filename, &path);
585 error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS);
590 if (!capable(CAP_SYS_CHROOT))
592 error = security_path_chroot(&path);
596 set_fs_root(current->fs, &path);
604 SYSCALL_DEFINE2(fchmod, unsigned int, fd, mode_t, mode)
606 struct inode * inode;
607 struct dentry * dentry;
610 struct iattr newattrs;
616 dentry = file->f_path.dentry;
617 inode = dentry->d_inode;
619 audit_inode(NULL, dentry);
621 err = mnt_want_write_file(file);
624 mutex_lock(&inode->i_mutex);
625 err = security_path_chmod(dentry, file->f_vfsmnt, mode);
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);
634 mutex_unlock(&inode->i_mutex);
635 mnt_drop_write(file->f_path.mnt);
642 SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, mode_t, mode)
647 struct iattr newattrs;
649 error = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path);
652 inode = path.dentry->d_inode;
654 error = mnt_want_write(path.mnt);
657 mutex_lock(&inode->i_mutex);
658 error = security_path_chmod(path.dentry, path.mnt, mode);
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);
667 mutex_unlock(&inode->i_mutex);
668 mnt_drop_write(path.mnt);
675 SYSCALL_DEFINE2(chmod, const char __user *, filename, mode_t, mode)
677 return sys_fchmodat(AT_FDCWD, filename, mode);
680 static int chown_common(struct path *path, uid_t user, gid_t group)
682 struct inode *inode = path->dentry->d_inode;
684 struct iattr newattrs;
686 newattrs.ia_valid = ATTR_CTIME;
687 if (user != (uid_t) -1) {
688 newattrs.ia_valid |= ATTR_UID;
689 newattrs.ia_uid = user;
691 if (group != (gid_t) -1) {
692 newattrs.ia_valid |= ATTR_GID;
693 newattrs.ia_gid = group;
695 if (!S_ISDIR(inode->i_mode))
697 ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
698 mutex_lock(&inode->i_mutex);
699 error = security_path_chown(path, user, group);
701 error = notify_change(path->dentry, &newattrs);
702 mutex_unlock(&inode->i_mutex);
707 SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group)
712 error = user_path(filename, &path);
715 error = mnt_want_write(path.mnt);
718 error = chown_common(&path, user, group);
719 mnt_drop_write(path.mnt);
726 SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user,
727 gid_t, group, int, flag)
733 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
736 follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
737 error = user_path_at(dfd, filename, follow, &path);
740 error = mnt_want_write(path.mnt);
743 error = chown_common(&path, user, group);
744 mnt_drop_write(path.mnt);
751 SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group)
756 error = user_lpath(filename, &path);
759 error = mnt_want_write(path.mnt);
762 error = chown_common(&path, user, group);
763 mnt_drop_write(path.mnt);
770 SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)
774 struct dentry * dentry;
780 error = mnt_want_write_file(file);
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);
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().
799 static inline int __get_file_write_access(struct inode *inode,
800 struct vfsmount *mnt)
803 error = get_write_access(inode);
807 * Do not take mount writer counts on
808 * special files since no writes to
809 * the mount itself will occur.
811 if (!special_file(inode->i_mode)) {
813 * Balanced in __fput()
815 error = mnt_want_write(mnt);
817 put_write_access(inode);
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)
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);
838 if (!special_file(inode->i_mode))
842 f->f_mapping = inode->i_mapping;
843 f->f_path.dentry = dentry;
846 f->f_op = fops_get(inode->i_fop);
847 file_move(f, &inode->i_sb->s_files);
849 error = security_dentry_open(f, cred);
853 if (!open && f->f_op)
854 open = f->f_op->open;
856 error = open(inode, f);
861 f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
863 file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
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))) {
871 f = ERR_PTR(-EINVAL);
879 if (f->f_mode & FMODE_WRITE) {
880 put_write_access(inode);
881 if (!special_file(inode->i_mode)) {
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.
893 f->f_path.dentry = NULL;
894 f->f_path.mnt = NULL;
899 return ERR_PTR(error);
903 * lookup_instantiate_filp - instantiates the open intent filp
904 * @nd: pointer to nameidata
905 * @dentry: pointer to dentry
906 * @open: open callback
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
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.
921 struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
922 int (*open)(struct inode *, struct file *))
924 const struct cred *cred = current_cred();
926 if (IS_ERR(nd->intent.open.file))
930 nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt),
931 nd->intent.open.flags - 1,
932 nd->intent.open.file,
935 return nd->intent.open.file;
937 release_open_intent(nd);
938 nd->intent.open.file = (struct file *)dentry;
941 EXPORT_SYMBOL_GPL(lookup_instantiate_filp);
944 * nameidata_to_filp - convert a nameidata to an open filp.
945 * @nd: pointer to nameidata
948 * Note that this function destroys the original nameidata
950 struct file *nameidata_to_filp(struct nameidata *nd, int flags)
952 const struct cred *cred = current_cred();
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,
967 * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
970 struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags,
971 const struct cred *cred)
976 validate_creds(cred);
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
985 printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__);
987 return ERR_PTR(-EINVAL);
991 f = get_empty_filp();
995 return ERR_PTR(error);
998 return __dentry_open(dentry, mnt, flags, f, NULL, cred);
1000 EXPORT_SYMBOL(dentry_open);
1002 static void __put_unused_fd(struct files_struct *files, unsigned int fd)
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;
1010 void put_unused_fd(unsigned int fd)
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);
1018 EXPORT_SYMBOL(put_unused_fd);
1021 * Install a file pointer in the fd array.
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.
1029 * It should never happen - if we allow dup2() do it, _really_ bad things
1033 void fd_install(unsigned int fd, struct file *file)
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);
1044 EXPORT_SYMBOL(fd_install);
1046 long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
1048 char *tmp = getname(filename);
1049 int fd = PTR_ERR(tmp);
1052 fd = get_unused_fd_flags(flags);
1054 struct file *f = do_filp_open(dfd, tmp, flags, mode, 0);
1059 fsnotify_open(f->f_path.dentry);
1068 SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, int, mode)
1072 if (force_o_largefile())
1073 flags |= O_LARGEFILE;
1075 ret = do_sys_open(AT_FDCWD, filename, flags, mode);
1076 /* avoid REGPARM breakage on x86: */
1077 asmlinkage_protect(3, ret, filename, flags, mode);
1081 SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags,
1086 if (force_o_largefile())
1087 flags |= O_LARGEFILE;
1089 ret = do_sys_open(dfd, filename, flags, mode);
1090 /* avoid REGPARM breakage on x86: */
1091 asmlinkage_protect(4, ret, dfd, filename, flags, mode);
1098 * For backward compatibility? Maybe this should be moved
1099 * into arch/i386 instead?
1101 SYSCALL_DEFINE2(creat, const char __user *, pathname, int, mode)
1103 return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
1109 * "id" is the POSIX thread ID. We use the
1110 * files pointer for this..
1112 int filp_close(struct file *filp, fl_owner_t id)
1116 if (!file_count(filp)) {
1117 printk(KERN_ERR "VFS: Close: file count is 0\n");
1121 if (filp->f_op && filp->f_op->flush)
1122 retval = filp->f_op->flush(filp, id);
1124 dnotify_flush(filp, id);
1125 locks_remove_posix(filp, id);
1130 EXPORT_SYMBOL(filp_close);
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.
1137 SYSCALL_DEFINE1(close, unsigned int, fd)
1140 struct files_struct *files = current->files;
1141 struct fdtable *fdt;
1144 spin_lock(&files->file_lock);
1145 fdt = files_fdtable(files);
1146 if (fd >= fdt->max_fds)
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);
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))
1167 spin_unlock(&files->file_lock);
1170 EXPORT_SYMBOL(sys_close);
1173 * This routine simulates a hangup on the tty, to arrange that users
1174 * are given clean terminals at login time.
1176 SYSCALL_DEFINE0(vhangup)
1178 if (capable(CAP_SYS_TTY_CONFIG)) {
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.
1191 int generic_file_open(struct inode * inode, struct file * filp)
1193 if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1198 EXPORT_SYMBOL(generic_file_open);
1201 * This is used by subsystems that don't want seekable
1204 int nonseekable_open(struct inode *inode, struct file *filp)
1206 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1210 EXPORT_SYMBOL(nonseekable_open);