4 * Copyright (C) 1991, 1992 Linus Torvalds
7 #include <linux/string.h>
9 #include <linux/file.h>
10 #include <linux/quotaops.h>
11 #include <linux/fsnotify.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/tty.h>
15 #include <linux/namei.h>
16 #include <linux/backing-dev.h>
17 #include <linux/capability.h>
18 #include <linux/security.h>
19 #include <linux/mount.h>
20 #include <linux/vfs.h>
21 #include <linux/fcntl.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>
31 int vfs_statfs(struct dentry *dentry, struct kstatfs *buf)
37 if (dentry->d_sb->s_op->statfs) {
38 memset(buf, 0, sizeof(*buf));
39 retval = security_sb_statfs(dentry);
42 retval = dentry->d_sb->s_op->statfs(dentry, buf);
43 if (retval == 0 && buf->f_frsize == 0)
44 buf->f_frsize = buf->f_bsize;
50 EXPORT_SYMBOL(vfs_statfs);
52 static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf)
57 retval = vfs_statfs(dentry, &st);
61 if (sizeof(*buf) == sizeof(st))
62 memcpy(buf, &st, sizeof(st));
64 if (sizeof buf->f_blocks == 4) {
65 if ((st.f_blocks | st.f_bfree | st.f_bavail) &
66 0xffffffff00000000ULL)
69 * f_files and f_ffree may be -1; it's okay to stuff
72 if (st.f_files != -1 &&
73 (st.f_files & 0xffffffff00000000ULL))
75 if (st.f_ffree != -1 &&
76 (st.f_ffree & 0xffffffff00000000ULL))
80 buf->f_type = st.f_type;
81 buf->f_bsize = st.f_bsize;
82 buf->f_blocks = st.f_blocks;
83 buf->f_bfree = st.f_bfree;
84 buf->f_bavail = st.f_bavail;
85 buf->f_files = st.f_files;
86 buf->f_ffree = st.f_ffree;
87 buf->f_fsid = st.f_fsid;
88 buf->f_namelen = st.f_namelen;
89 buf->f_frsize = st.f_frsize;
90 memset(buf->f_spare, 0, sizeof(buf->f_spare));
95 static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf)
100 retval = vfs_statfs(dentry, &st);
104 if (sizeof(*buf) == sizeof(st))
105 memcpy(buf, &st, sizeof(st));
107 buf->f_type = st.f_type;
108 buf->f_bsize = st.f_bsize;
109 buf->f_blocks = st.f_blocks;
110 buf->f_bfree = st.f_bfree;
111 buf->f_bavail = st.f_bavail;
112 buf->f_files = st.f_files;
113 buf->f_ffree = st.f_ffree;
114 buf->f_fsid = st.f_fsid;
115 buf->f_namelen = st.f_namelen;
116 buf->f_frsize = st.f_frsize;
117 memset(buf->f_spare, 0, sizeof(buf->f_spare));
122 asmlinkage long sys_statfs(const char __user * path, struct statfs __user * buf)
127 error = user_path_walk(path, &nd);
130 error = vfs_statfs_native(nd.path.dentry, &tmp);
131 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
139 asmlinkage long sys_statfs64(const char __user *path, size_t sz, struct statfs64 __user *buf)
144 if (sz != sizeof(*buf))
146 error = user_path_walk(path, &nd);
149 error = vfs_statfs64(nd.path.dentry, &tmp);
150 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
158 asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf)
168 error = vfs_statfs_native(file->f_path.dentry, &tmp);
169 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
176 asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf)
182 if (sz != sizeof(*buf))
189 error = vfs_statfs64(file->f_path.dentry, &tmp);
190 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
197 int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
201 struct iattr newattrs;
203 /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */
207 newattrs.ia_size = length;
208 newattrs.ia_valid = ATTR_SIZE | time_attrs;
210 newattrs.ia_file = filp;
211 newattrs.ia_valid |= ATTR_FILE;
214 /* Remove suid/sgid on truncate too */
215 newattrs.ia_valid |= should_remove_suid(dentry);
217 mutex_lock(&dentry->d_inode->i_mutex);
218 err = notify_change(dentry, &newattrs);
219 mutex_unlock(&dentry->d_inode->i_mutex);
223 static long do_sys_truncate(const char __user * path, loff_t length)
226 struct inode * inode;
230 if (length < 0) /* sorry, but loff_t says... */
233 error = user_path_walk(path, &nd);
236 inode = nd.path.dentry->d_inode;
238 /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
240 if (S_ISDIR(inode->i_mode))
244 if (!S_ISREG(inode->i_mode))
247 error = mnt_want_write(nd.path.mnt);
251 error = vfs_permission(&nd, MAY_WRITE);
253 goto mnt_drop_write_and_out;
256 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
257 goto mnt_drop_write_and_out;
259 error = get_write_access(inode);
261 goto mnt_drop_write_and_out;
264 * Make sure that there are no leases. get_write_access() protects
265 * against the truncate racing with a lease-granting setlease().
267 error = break_lease(inode, FMODE_WRITE);
269 goto put_write_and_out;
271 error = locks_verify_truncate(inode, NULL, length);
274 error = do_truncate(nd.path.dentry, length, 0, NULL);
278 put_write_access(inode);
279 mnt_drop_write_and_out:
280 mnt_drop_write(nd.path.mnt);
287 asmlinkage long sys_truncate(const char __user * path, unsigned long length)
289 /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */
290 return do_sys_truncate(path, (long)length);
293 static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
295 struct inode * inode;
296 struct dentry *dentry;
308 /* explicitly opened as large or we are on 64-bit box */
309 if (file->f_flags & O_LARGEFILE)
312 dentry = file->f_path.dentry;
313 inode = dentry->d_inode;
315 if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
319 /* Cannot ftruncate over 2^31 bytes without large file support */
320 if (small && length > MAX_NON_LFS)
324 if (IS_APPEND(inode))
327 error = locks_verify_truncate(inode, file, length);
329 error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file);
336 asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length)
338 long ret = do_sys_ftruncate(fd, length, 1);
339 /* avoid REGPARM breakage on x86: */
340 asmlinkage_protect(2, ret, fd, length);
344 /* LFS versions of truncate are only needed on 32 bit machines */
345 #if BITS_PER_LONG == 32
346 asmlinkage long sys_truncate64(const char __user * path, loff_t length)
348 return do_sys_truncate(path, length);
351 asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length)
353 long ret = do_sys_ftruncate(fd, length, 0);
354 /* avoid REGPARM breakage on x86: */
355 asmlinkage_protect(2, ret, fd, length);
360 asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len)
366 if (offset < 0 || len <= 0)
369 /* Return error if mode is not supported */
371 if (mode && !(mode & FALLOC_FL_KEEP_SIZE))
378 if (!(file->f_mode & FMODE_WRITE))
381 * Revalidate the write permissions, in case security policy has
382 * changed since the files were opened.
384 ret = security_file_permission(file, MAY_WRITE);
388 inode = file->f_path.dentry->d_inode;
391 if (S_ISFIFO(inode->i_mode))
396 * Let individual file system decide if it supports preallocation
397 * for directories or not.
399 if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
403 /* Check for wrap through zero too */
404 if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
407 if (inode->i_op && inode->i_op->fallocate)
408 ret = inode->i_op->fallocate(inode, mode, offset, len);
419 * access() needs to use the real uid/gid, not the effective uid/gid.
420 * We do this by temporarily clearing all FS-related capabilities and
421 * switching the fsuid/fsgid around to the real ones.
423 asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
426 int old_fsuid, old_fsgid;
427 kernel_cap_t old_cap;
430 if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */
433 old_fsuid = current->fsuid;
434 old_fsgid = current->fsgid;
435 old_cap = current->cap_effective;
437 current->fsuid = current->uid;
438 current->fsgid = current->gid;
441 * Clear the capabilities if we switch to a non-root user
443 * FIXME: There is a race here against sys_capset. The
444 * capabilities can change yet we will restore the old
445 * value below. We should hold task_capabilities_lock,
446 * but we cannot because user_path_walk can sleep.
449 cap_clear(current->cap_effective);
451 current->cap_effective = current->cap_permitted;
453 res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
457 res = vfs_permission(&nd, mode);
458 /* SuS v2 requires we report a read only fs too */
459 if(res || !(mode & S_IWOTH) ||
460 special_file(nd.path.dentry->d_inode->i_mode))
461 goto out_path_release;
463 if(IS_RDONLY(nd.path.dentry->d_inode))
469 current->fsuid = old_fsuid;
470 current->fsgid = old_fsgid;
471 current->cap_effective = old_cap;
476 asmlinkage long sys_access(const char __user *filename, int mode)
478 return sys_faccessat(AT_FDCWD, filename, mode);
481 asmlinkage long sys_chdir(const char __user * filename)
486 error = __user_walk(filename,
487 LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_CHDIR, &nd);
491 error = vfs_permission(&nd, MAY_EXEC);
495 set_fs_pwd(current->fs, &nd.path);
503 asmlinkage long sys_fchdir(unsigned int fd)
514 inode = file->f_path.dentry->d_inode;
517 if (!S_ISDIR(inode->i_mode))
520 error = file_permission(file, MAY_EXEC);
522 set_fs_pwd(current->fs, &file->f_path);
529 asmlinkage long sys_chroot(const char __user * filename)
534 error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
538 error = vfs_permission(&nd, MAY_EXEC);
543 if (!capable(CAP_SYS_CHROOT))
546 set_fs_root(current->fs, &nd.path);
555 asmlinkage long sys_fchmod(unsigned int fd, mode_t mode)
557 struct inode * inode;
558 struct dentry * dentry;
561 struct iattr newattrs;
567 dentry = file->f_path.dentry;
568 inode = dentry->d_inode;
570 audit_inode(NULL, dentry);
572 err = mnt_want_write(file->f_path.mnt);
576 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
578 mutex_lock(&inode->i_mutex);
579 if (mode == (mode_t) -1)
580 mode = inode->i_mode;
581 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
582 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
583 err = notify_change(dentry, &newattrs);
584 mutex_unlock(&inode->i_mutex);
587 mnt_drop_write(file->f_path.mnt);
594 asmlinkage long sys_fchmodat(int dfd, const char __user *filename,
598 struct inode * inode;
600 struct iattr newattrs;
602 error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd);
605 inode = nd.path.dentry->d_inode;
607 error = mnt_want_write(nd.path.mnt);
612 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
615 mutex_lock(&inode->i_mutex);
616 if (mode == (mode_t) -1)
617 mode = inode->i_mode;
618 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
619 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
620 error = notify_change(nd.path.dentry, &newattrs);
621 mutex_unlock(&inode->i_mutex);
624 mnt_drop_write(nd.path.mnt);
631 asmlinkage long sys_chmod(const char __user *filename, mode_t mode)
633 return sys_fchmodat(AT_FDCWD, filename, mode);
636 static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
638 struct inode * inode;
640 struct iattr newattrs;
643 if (!(inode = dentry->d_inode)) {
644 printk(KERN_ERR "chown_common: NULL inode\n");
648 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
650 newattrs.ia_valid = ATTR_CTIME;
651 if (user != (uid_t) -1) {
652 newattrs.ia_valid |= ATTR_UID;
653 newattrs.ia_uid = user;
655 if (group != (gid_t) -1) {
656 newattrs.ia_valid |= ATTR_GID;
657 newattrs.ia_gid = group;
659 if (!S_ISDIR(inode->i_mode))
661 ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
662 mutex_lock(&inode->i_mutex);
663 error = notify_change(dentry, &newattrs);
664 mutex_unlock(&inode->i_mutex);
669 asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group)
674 error = user_path_walk(filename, &nd);
677 error = mnt_want_write(nd.path.mnt);
680 error = chown_common(nd.path.dentry, user, group);
681 mnt_drop_write(nd.path.mnt);
688 asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user,
689 gid_t group, int flag)
695 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
698 follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
699 error = __user_walk_fd(dfd, filename, follow, &nd);
702 error = mnt_want_write(nd.path.mnt);
705 error = chown_common(nd.path.dentry, user, group);
706 mnt_drop_write(nd.path.mnt);
713 asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group)
718 error = user_path_walk_link(filename, &nd);
721 error = mnt_want_write(nd.path.mnt);
724 error = chown_common(nd.path.dentry, user, group);
725 mnt_drop_write(nd.path.mnt);
733 asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
737 struct dentry * dentry;
743 error = mnt_want_write(file->f_path.mnt);
746 dentry = file->f_path.dentry;
747 audit_inode(NULL, dentry);
748 error = chown_common(dentry, user, group);
749 mnt_drop_write(file->f_path.mnt);
757 * You have to be very careful that these write
758 * counts get cleaned up in error cases and
759 * upon __fput(). This should probably never
760 * be called outside of __dentry_open().
762 static inline int __get_file_write_access(struct inode *inode,
763 struct vfsmount *mnt)
766 error = get_write_access(inode);
770 * Do not take mount writer counts on
771 * special files since no writes to
772 * the mount itself will occur.
774 if (!special_file(inode->i_mode)) {
776 * Balanced in __fput()
778 error = mnt_want_write(mnt);
780 put_write_access(inode);
785 static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
786 int flags, struct file *f,
787 int (*open)(struct inode *, struct file *))
793 f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK |
794 FMODE_PREAD | FMODE_PWRITE;
795 inode = dentry->d_inode;
796 if (f->f_mode & FMODE_WRITE) {
797 error = __get_file_write_access(inode, mnt);
802 f->f_mapping = inode->i_mapping;
803 f->f_path.dentry = dentry;
806 f->f_op = fops_get(inode->i_fop);
807 file_move(f, &inode->i_sb->s_files);
809 error = security_dentry_open(f);
813 if (!open && f->f_op)
814 open = f->f_op->open;
816 error = open(inode, f);
821 f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
823 file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
825 /* NB: we're sure to have correct a_ops only after f_op->open */
826 if (f->f_flags & O_DIRECT) {
827 if (!f->f_mapping->a_ops ||
828 ((!f->f_mapping->a_ops->direct_IO) &&
829 (!f->f_mapping->a_ops->get_xip_page))) {
831 f = ERR_PTR(-EINVAL);
839 if (f->f_mode & FMODE_WRITE) {
840 put_write_access(inode);
841 if (!special_file(inode->i_mode))
845 f->f_path.dentry = NULL;
846 f->f_path.mnt = NULL;
851 return ERR_PTR(error);
855 * lookup_instantiate_filp - instantiates the open intent filp
856 * @nd: pointer to nameidata
857 * @dentry: pointer to dentry
858 * @open: open callback
860 * Helper for filesystems that want to use lookup open intents and pass back
861 * a fully instantiated struct file to the caller.
862 * This function is meant to be called from within a filesystem's
864 * Beware of calling it for non-regular files! Those ->open methods might block
865 * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo,
866 * leading to a deadlock, as nobody can open that fifo anymore, because
867 * another process to open fifo will block on locked parent when doing lookup).
868 * Note that in case of error, nd->intent.open.file is destroyed, but the
869 * path information remains valid.
870 * If the open callback is set to NULL, then the standard f_op->open()
871 * filesystem callback is substituted.
873 struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
874 int (*open)(struct inode *, struct file *))
876 if (IS_ERR(nd->intent.open.file))
880 nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt),
881 nd->intent.open.flags - 1,
882 nd->intent.open.file,
885 return nd->intent.open.file;
887 release_open_intent(nd);
888 nd->intent.open.file = (struct file *)dentry;
891 EXPORT_SYMBOL_GPL(lookup_instantiate_filp);
894 * nameidata_to_filp - convert a nameidata to an open filp.
895 * @nd: pointer to nameidata
898 * Note that this function destroys the original nameidata
900 struct file *nameidata_to_filp(struct nameidata *nd, int flags)
904 /* Pick up the filp from the open intent */
905 filp = nd->intent.open.file;
906 /* Has the filesystem initialised the file for us? */
907 if (filp->f_path.dentry == NULL)
908 filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp,
916 * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
919 struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
925 * We must always pass in a valid mount pointer. Historically
926 * callers got away with not passing it, but we must enforce this at
927 * the earliest possible point now to avoid strange problems deep in the
931 printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__);
933 return ERR_PTR(-EINVAL);
937 f = get_empty_filp();
941 return ERR_PTR(error);
944 return __dentry_open(dentry, mnt, flags, f, NULL);
946 EXPORT_SYMBOL(dentry_open);
949 * Find an empty file descriptor entry, and mark it busy.
951 int get_unused_fd_flags(int flags)
953 struct files_struct * files = current->files;
958 spin_lock(&files->file_lock);
961 fdt = files_fdtable(files);
962 fd = find_next_zero_bit(fdt->open_fds->fds_bits, fdt->max_fds,
966 * N.B. For clone tasks sharing a files structure, this test
967 * will limit the total number of files that can be opened.
969 if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
972 /* Do we need to expand the fd array or fd set? */
973 error = expand_files(files, fd);
979 * If we needed to expand the fs array we
980 * might have blocked - try again.
986 FD_SET(fd, fdt->open_fds);
987 if (flags & O_CLOEXEC)
988 FD_SET(fd, fdt->close_on_exec);
990 FD_CLR(fd, fdt->close_on_exec);
991 files->next_fd = fd + 1;
994 if (fdt->fd[fd] != NULL) {
995 printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd);
1002 spin_unlock(&files->file_lock);
1006 int get_unused_fd(void)
1008 return get_unused_fd_flags(0);
1011 EXPORT_SYMBOL(get_unused_fd);
1013 static void __put_unused_fd(struct files_struct *files, unsigned int fd)
1015 struct fdtable *fdt = files_fdtable(files);
1016 __FD_CLR(fd, fdt->open_fds);
1017 if (fd < files->next_fd)
1018 files->next_fd = fd;
1021 void put_unused_fd(unsigned int fd)
1023 struct files_struct *files = current->files;
1024 spin_lock(&files->file_lock);
1025 __put_unused_fd(files, fd);
1026 spin_unlock(&files->file_lock);
1029 EXPORT_SYMBOL(put_unused_fd);
1032 * Install a file pointer in the fd array.
1034 * The VFS is full of places where we drop the files lock between
1035 * setting the open_fds bitmap and installing the file in the file
1036 * array. At any such point, we are vulnerable to a dup2() race
1037 * installing a file in the array before us. We need to detect this and
1038 * fput() the struct file we are about to overwrite in this case.
1040 * It should never happen - if we allow dup2() do it, _really_ bad things
1044 void fd_install(unsigned int fd, struct file *file)
1046 struct files_struct *files = current->files;
1047 struct fdtable *fdt;
1048 spin_lock(&files->file_lock);
1049 fdt = files_fdtable(files);
1050 BUG_ON(fdt->fd[fd] != NULL);
1051 rcu_assign_pointer(fdt->fd[fd], file);
1052 spin_unlock(&files->file_lock);
1055 EXPORT_SYMBOL(fd_install);
1057 long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
1059 char *tmp = getname(filename);
1060 int fd = PTR_ERR(tmp);
1063 fd = get_unused_fd_flags(flags);
1065 struct file *f = do_filp_open(dfd, tmp, flags, mode);
1070 fsnotify_open(f->f_path.dentry);
1079 asmlinkage long sys_open(const char __user *filename, int flags, int mode)
1083 if (force_o_largefile())
1084 flags |= O_LARGEFILE;
1086 ret = do_sys_open(AT_FDCWD, filename, flags, mode);
1087 /* avoid REGPARM breakage on x86: */
1088 asmlinkage_protect(3, ret, filename, flags, mode);
1092 asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
1097 if (force_o_largefile())
1098 flags |= O_LARGEFILE;
1100 ret = do_sys_open(dfd, filename, flags, mode);
1101 /* avoid REGPARM breakage on x86: */
1102 asmlinkage_protect(4, ret, dfd, filename, flags, mode);
1109 * For backward compatibility? Maybe this should be moved
1110 * into arch/i386 instead?
1112 asmlinkage long sys_creat(const char __user * pathname, int mode)
1114 return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
1120 * "id" is the POSIX thread ID. We use the
1121 * files pointer for this..
1123 int filp_close(struct file *filp, fl_owner_t id)
1127 if (!file_count(filp)) {
1128 printk(KERN_ERR "VFS: Close: file count is 0\n");
1132 if (filp->f_op && filp->f_op->flush)
1133 retval = filp->f_op->flush(filp, id);
1135 dnotify_flush(filp, id);
1136 locks_remove_posix(filp, id);
1141 EXPORT_SYMBOL(filp_close);
1144 * Careful here! We test whether the file pointer is NULL before
1145 * releasing the fd. This ensures that one clone task can't release
1146 * an fd while another clone is opening it.
1148 asmlinkage long sys_close(unsigned int fd)
1151 struct files_struct *files = current->files;
1152 struct fdtable *fdt;
1155 spin_lock(&files->file_lock);
1156 fdt = files_fdtable(files);
1157 if (fd >= fdt->max_fds)
1162 rcu_assign_pointer(fdt->fd[fd], NULL);
1163 FD_CLR(fd, fdt->close_on_exec);
1164 __put_unused_fd(files, fd);
1165 spin_unlock(&files->file_lock);
1166 retval = filp_close(filp, files);
1168 /* can't restart close syscall because file table entry was cleared */
1169 if (unlikely(retval == -ERESTARTSYS ||
1170 retval == -ERESTARTNOINTR ||
1171 retval == -ERESTARTNOHAND ||
1172 retval == -ERESTART_RESTARTBLOCK))
1178 spin_unlock(&files->file_lock);
1182 EXPORT_SYMBOL(sys_close);
1185 * This routine simulates a hangup on the tty, to arrange that users
1186 * are given clean terminals at login time.
1188 asmlinkage long sys_vhangup(void)
1190 if (capable(CAP_SYS_TTY_CONFIG)) {
1191 /* XXX: this needs locking */
1192 tty_vhangup(current->signal->tty);
1199 * Called when an inode is about to be open.
1200 * We use this to disallow opening large files on 32bit systems if
1201 * the caller didn't specify O_LARGEFILE. On 64bit systems we force
1202 * on this flag in sys_open.
1204 int generic_file_open(struct inode * inode, struct file * filp)
1206 if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1211 EXPORT_SYMBOL(generic_file_open);
1214 * This is used by subsystems that don't want seekable
1217 int nonseekable_open(struct inode *inode, struct file *filp)
1219 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1223 EXPORT_SYMBOL(nonseekable_open);