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 = vfs_permission(&nd, MAY_WRITE);
252 if (IS_RDONLY(inode))
256 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
259 error = get_write_access(inode);
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);
285 asmlinkage long sys_truncate(const char __user * path, unsigned long length)
287 /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */
288 return do_sys_truncate(path, (long)length);
291 static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
293 struct inode * inode;
294 struct dentry *dentry;
306 /* explicitly opened as large or we are on 64-bit box */
307 if (file->f_flags & O_LARGEFILE)
310 dentry = file->f_path.dentry;
311 inode = dentry->d_inode;
313 if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
317 /* Cannot ftruncate over 2^31 bytes without large file support */
318 if (small && length > MAX_NON_LFS)
322 if (IS_APPEND(inode))
325 error = locks_verify_truncate(inode, file, length);
327 error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file);
334 asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length)
336 long ret = do_sys_ftruncate(fd, length, 1);
337 /* avoid REGPARM breakage on x86: */
338 asmlinkage_protect(2, ret, fd, length);
342 /* LFS versions of truncate are only needed on 32 bit machines */
343 #if BITS_PER_LONG == 32
344 asmlinkage long sys_truncate64(const char __user * path, loff_t length)
346 return do_sys_truncate(path, length);
349 asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length)
351 long ret = do_sys_ftruncate(fd, length, 0);
352 /* avoid REGPARM breakage on x86: */
353 asmlinkage_protect(2, ret, fd, length);
358 asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len)
364 if (offset < 0 || len <= 0)
367 /* Return error if mode is not supported */
369 if (mode && !(mode & FALLOC_FL_KEEP_SIZE))
376 if (!(file->f_mode & FMODE_WRITE))
379 * Revalidate the write permissions, in case security policy has
380 * changed since the files were opened.
382 ret = security_file_permission(file, MAY_WRITE);
386 inode = file->f_path.dentry->d_inode;
389 if (S_ISFIFO(inode->i_mode))
394 * Let individual file system decide if it supports preallocation
395 * for directories or not.
397 if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
401 /* Check for wrap through zero too */
402 if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
405 if (inode->i_op && inode->i_op->fallocate)
406 ret = inode->i_op->fallocate(inode, mode, offset, len);
417 * access() needs to use the real uid/gid, not the effective uid/gid.
418 * We do this by temporarily clearing all FS-related capabilities and
419 * switching the fsuid/fsgid around to the real ones.
421 asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
424 int old_fsuid, old_fsgid;
425 kernel_cap_t old_cap;
428 if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */
431 old_fsuid = current->fsuid;
432 old_fsgid = current->fsgid;
433 old_cap = current->cap_effective;
435 current->fsuid = current->uid;
436 current->fsgid = current->gid;
439 * Clear the capabilities if we switch to a non-root user
441 * FIXME: There is a race here against sys_capset. The
442 * capabilities can change yet we will restore the old
443 * value below. We should hold task_capabilities_lock,
444 * but we cannot because user_path_walk can sleep.
447 cap_clear(current->cap_effective);
449 current->cap_effective = current->cap_permitted;
451 res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
455 res = vfs_permission(&nd, mode);
456 /* SuS v2 requires we report a read only fs too */
457 if(res || !(mode & S_IWOTH) ||
458 special_file(nd.path.dentry->d_inode->i_mode))
459 goto out_path_release;
461 if(IS_RDONLY(nd.path.dentry->d_inode))
467 current->fsuid = old_fsuid;
468 current->fsgid = old_fsgid;
469 current->cap_effective = old_cap;
474 asmlinkage long sys_access(const char __user *filename, int mode)
476 return sys_faccessat(AT_FDCWD, filename, mode);
479 asmlinkage long sys_chdir(const char __user * filename)
484 error = __user_walk(filename,
485 LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_CHDIR, &nd);
489 error = vfs_permission(&nd, MAY_EXEC);
493 set_fs_pwd(current->fs, &nd.path);
501 asmlinkage long sys_fchdir(unsigned int fd)
512 inode = file->f_path.dentry->d_inode;
515 if (!S_ISDIR(inode->i_mode))
518 error = file_permission(file, MAY_EXEC);
520 set_fs_pwd(current->fs, &file->f_path);
527 asmlinkage long sys_chroot(const char __user * filename)
532 error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
536 error = vfs_permission(&nd, MAY_EXEC);
541 if (!capable(CAP_SYS_CHROOT))
544 set_fs_root(current->fs, &nd.path);
553 asmlinkage long sys_fchmod(unsigned int fd, mode_t mode)
555 struct inode * inode;
556 struct dentry * dentry;
559 struct iattr newattrs;
565 dentry = file->f_path.dentry;
566 inode = dentry->d_inode;
568 audit_inode(NULL, dentry);
570 err = mnt_want_write(file->f_path.mnt);
574 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
576 mutex_lock(&inode->i_mutex);
577 if (mode == (mode_t) -1)
578 mode = inode->i_mode;
579 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
580 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
581 err = notify_change(dentry, &newattrs);
582 mutex_unlock(&inode->i_mutex);
585 mnt_drop_write(file->f_path.mnt);
592 asmlinkage long sys_fchmodat(int dfd, const char __user *filename,
596 struct inode * inode;
598 struct iattr newattrs;
600 error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd);
603 inode = nd.path.dentry->d_inode;
605 error = mnt_want_write(nd.path.mnt);
610 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
613 mutex_lock(&inode->i_mutex);
614 if (mode == (mode_t) -1)
615 mode = inode->i_mode;
616 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
617 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
618 error = notify_change(nd.path.dentry, &newattrs);
619 mutex_unlock(&inode->i_mutex);
622 mnt_drop_write(nd.path.mnt);
629 asmlinkage long sys_chmod(const char __user *filename, mode_t mode)
631 return sys_fchmodat(AT_FDCWD, filename, mode);
634 static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
636 struct inode * inode;
638 struct iattr newattrs;
641 if (!(inode = dentry->d_inode)) {
642 printk(KERN_ERR "chown_common: NULL inode\n");
646 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
648 newattrs.ia_valid = ATTR_CTIME;
649 if (user != (uid_t) -1) {
650 newattrs.ia_valid |= ATTR_UID;
651 newattrs.ia_uid = user;
653 if (group != (gid_t) -1) {
654 newattrs.ia_valid |= ATTR_GID;
655 newattrs.ia_gid = group;
657 if (!S_ISDIR(inode->i_mode))
659 ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
660 mutex_lock(&inode->i_mutex);
661 error = notify_change(dentry, &newattrs);
662 mutex_unlock(&inode->i_mutex);
667 asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group)
672 error = user_path_walk(filename, &nd);
675 error = mnt_want_write(nd.path.mnt);
678 error = chown_common(nd.path.dentry, user, group);
679 mnt_drop_write(nd.path.mnt);
686 asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user,
687 gid_t group, int flag)
693 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
696 follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
697 error = __user_walk_fd(dfd, filename, follow, &nd);
700 error = mnt_want_write(nd.path.mnt);
703 error = chown_common(nd.path.dentry, user, group);
704 mnt_drop_write(nd.path.mnt);
711 asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group)
716 error = user_path_walk_link(filename, &nd);
719 error = mnt_want_write(nd.path.mnt);
722 error = chown_common(nd.path.dentry, user, group);
723 mnt_drop_write(nd.path.mnt);
731 asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
735 struct dentry * dentry;
741 error = mnt_want_write(file->f_path.mnt);
744 dentry = file->f_path.dentry;
745 audit_inode(NULL, dentry);
746 error = chown_common(dentry, user, group);
747 mnt_drop_write(file->f_path.mnt);
755 * You have to be very careful that these write
756 * counts get cleaned up in error cases and
757 * upon __fput(). This should probably never
758 * be called outside of __dentry_open().
760 static inline int __get_file_write_access(struct inode *inode,
761 struct vfsmount *mnt)
764 error = get_write_access(inode);
768 * Do not take mount writer counts on
769 * special files since no writes to
770 * the mount itself will occur.
772 if (!special_file(inode->i_mode)) {
774 * Balanced in __fput()
776 error = mnt_want_write(mnt);
778 put_write_access(inode);
783 static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
784 int flags, struct file *f,
785 int (*open)(struct inode *, struct file *))
791 f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK |
792 FMODE_PREAD | FMODE_PWRITE;
793 inode = dentry->d_inode;
794 if (f->f_mode & FMODE_WRITE) {
795 error = __get_file_write_access(inode, mnt);
800 f->f_mapping = inode->i_mapping;
801 f->f_path.dentry = dentry;
804 f->f_op = fops_get(inode->i_fop);
805 file_move(f, &inode->i_sb->s_files);
807 error = security_dentry_open(f);
811 if (!open && f->f_op)
812 open = f->f_op->open;
814 error = open(inode, f);
819 f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
821 file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
823 /* NB: we're sure to have correct a_ops only after f_op->open */
824 if (f->f_flags & O_DIRECT) {
825 if (!f->f_mapping->a_ops ||
826 ((!f->f_mapping->a_ops->direct_IO) &&
827 (!f->f_mapping->a_ops->get_xip_page))) {
829 f = ERR_PTR(-EINVAL);
837 if (f->f_mode & FMODE_WRITE) {
838 put_write_access(inode);
839 if (!special_file(inode->i_mode))
843 f->f_path.dentry = NULL;
844 f->f_path.mnt = NULL;
849 return ERR_PTR(error);
853 * lookup_instantiate_filp - instantiates the open intent filp
854 * @nd: pointer to nameidata
855 * @dentry: pointer to dentry
856 * @open: open callback
858 * Helper for filesystems that want to use lookup open intents and pass back
859 * a fully instantiated struct file to the caller.
860 * This function is meant to be called from within a filesystem's
862 * Beware of calling it for non-regular files! Those ->open methods might block
863 * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo,
864 * leading to a deadlock, as nobody can open that fifo anymore, because
865 * another process to open fifo will block on locked parent when doing lookup).
866 * Note that in case of error, nd->intent.open.file is destroyed, but the
867 * path information remains valid.
868 * If the open callback is set to NULL, then the standard f_op->open()
869 * filesystem callback is substituted.
871 struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
872 int (*open)(struct inode *, struct file *))
874 if (IS_ERR(nd->intent.open.file))
878 nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt),
879 nd->intent.open.flags - 1,
880 nd->intent.open.file,
883 return nd->intent.open.file;
885 release_open_intent(nd);
886 nd->intent.open.file = (struct file *)dentry;
889 EXPORT_SYMBOL_GPL(lookup_instantiate_filp);
892 * nameidata_to_filp - convert a nameidata to an open filp.
893 * @nd: pointer to nameidata
896 * Note that this function destroys the original nameidata
898 struct file *nameidata_to_filp(struct nameidata *nd, int flags)
902 /* Pick up the filp from the open intent */
903 filp = nd->intent.open.file;
904 /* Has the filesystem initialised the file for us? */
905 if (filp->f_path.dentry == NULL)
906 filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp,
914 * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
917 struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
923 * We must always pass in a valid mount pointer. Historically
924 * callers got away with not passing it, but we must enforce this at
925 * the earliest possible point now to avoid strange problems deep in the
929 printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__);
931 return ERR_PTR(-EINVAL);
935 f = get_empty_filp();
939 return ERR_PTR(error);
942 return __dentry_open(dentry, mnt, flags, f, NULL);
944 EXPORT_SYMBOL(dentry_open);
947 * Find an empty file descriptor entry, and mark it busy.
949 int get_unused_fd_flags(int flags)
951 struct files_struct * files = current->files;
956 spin_lock(&files->file_lock);
959 fdt = files_fdtable(files);
960 fd = find_next_zero_bit(fdt->open_fds->fds_bits, fdt->max_fds,
964 * N.B. For clone tasks sharing a files structure, this test
965 * will limit the total number of files that can be opened.
967 if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
970 /* Do we need to expand the fd array or fd set? */
971 error = expand_files(files, fd);
977 * If we needed to expand the fs array we
978 * might have blocked - try again.
984 FD_SET(fd, fdt->open_fds);
985 if (flags & O_CLOEXEC)
986 FD_SET(fd, fdt->close_on_exec);
988 FD_CLR(fd, fdt->close_on_exec);
989 files->next_fd = fd + 1;
992 if (fdt->fd[fd] != NULL) {
993 printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd);
1000 spin_unlock(&files->file_lock);
1004 int get_unused_fd(void)
1006 return get_unused_fd_flags(0);
1009 EXPORT_SYMBOL(get_unused_fd);
1011 static void __put_unused_fd(struct files_struct *files, unsigned int fd)
1013 struct fdtable *fdt = files_fdtable(files);
1014 __FD_CLR(fd, fdt->open_fds);
1015 if (fd < files->next_fd)
1016 files->next_fd = fd;
1019 void put_unused_fd(unsigned int fd)
1021 struct files_struct *files = current->files;
1022 spin_lock(&files->file_lock);
1023 __put_unused_fd(files, fd);
1024 spin_unlock(&files->file_lock);
1027 EXPORT_SYMBOL(put_unused_fd);
1030 * Install a file pointer in the fd array.
1032 * The VFS is full of places where we drop the files lock between
1033 * setting the open_fds bitmap and installing the file in the file
1034 * array. At any such point, we are vulnerable to a dup2() race
1035 * installing a file in the array before us. We need to detect this and
1036 * fput() the struct file we are about to overwrite in this case.
1038 * It should never happen - if we allow dup2() do it, _really_ bad things
1042 void fd_install(unsigned int fd, struct file *file)
1044 struct files_struct *files = current->files;
1045 struct fdtable *fdt;
1046 spin_lock(&files->file_lock);
1047 fdt = files_fdtable(files);
1048 BUG_ON(fdt->fd[fd] != NULL);
1049 rcu_assign_pointer(fdt->fd[fd], file);
1050 spin_unlock(&files->file_lock);
1053 EXPORT_SYMBOL(fd_install);
1055 long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
1057 char *tmp = getname(filename);
1058 int fd = PTR_ERR(tmp);
1061 fd = get_unused_fd_flags(flags);
1063 struct file *f = do_filp_open(dfd, tmp, flags, mode);
1068 fsnotify_open(f->f_path.dentry);
1077 asmlinkage long sys_open(const char __user *filename, int flags, int mode)
1081 if (force_o_largefile())
1082 flags |= O_LARGEFILE;
1084 ret = do_sys_open(AT_FDCWD, filename, flags, mode);
1085 /* avoid REGPARM breakage on x86: */
1086 asmlinkage_protect(3, ret, filename, flags, mode);
1090 asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
1095 if (force_o_largefile())
1096 flags |= O_LARGEFILE;
1098 ret = do_sys_open(dfd, filename, flags, mode);
1099 /* avoid REGPARM breakage on x86: */
1100 asmlinkage_protect(4, ret, dfd, filename, flags, mode);
1107 * For backward compatibility? Maybe this should be moved
1108 * into arch/i386 instead?
1110 asmlinkage long sys_creat(const char __user * pathname, int mode)
1112 return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
1118 * "id" is the POSIX thread ID. We use the
1119 * files pointer for this..
1121 int filp_close(struct file *filp, fl_owner_t id)
1125 if (!file_count(filp)) {
1126 printk(KERN_ERR "VFS: Close: file count is 0\n");
1130 if (filp->f_op && filp->f_op->flush)
1131 retval = filp->f_op->flush(filp, id);
1133 dnotify_flush(filp, id);
1134 locks_remove_posix(filp, id);
1139 EXPORT_SYMBOL(filp_close);
1142 * Careful here! We test whether the file pointer is NULL before
1143 * releasing the fd. This ensures that one clone task can't release
1144 * an fd while another clone is opening it.
1146 asmlinkage long sys_close(unsigned int fd)
1149 struct files_struct *files = current->files;
1150 struct fdtable *fdt;
1153 spin_lock(&files->file_lock);
1154 fdt = files_fdtable(files);
1155 if (fd >= fdt->max_fds)
1160 rcu_assign_pointer(fdt->fd[fd], NULL);
1161 FD_CLR(fd, fdt->close_on_exec);
1162 __put_unused_fd(files, fd);
1163 spin_unlock(&files->file_lock);
1164 retval = filp_close(filp, files);
1166 /* can't restart close syscall because file table entry was cleared */
1167 if (unlikely(retval == -ERESTARTSYS ||
1168 retval == -ERESTARTNOINTR ||
1169 retval == -ERESTARTNOHAND ||
1170 retval == -ERESTART_RESTARTBLOCK))
1176 spin_unlock(&files->file_lock);
1180 EXPORT_SYMBOL(sys_close);
1183 * This routine simulates a hangup on the tty, to arrange that users
1184 * are given clean terminals at login time.
1186 asmlinkage long sys_vhangup(void)
1188 if (capable(CAP_SYS_TTY_CONFIG)) {
1189 /* XXX: this needs locking */
1190 tty_vhangup(current->signal->tty);
1197 * Called when an inode is about to be open.
1198 * We use this to disallow opening large files on 32bit systems if
1199 * the caller didn't specify O_LARGEFILE. On 64bit systems we force
1200 * on this flag in sys_open.
1202 int generic_file_open(struct inode * inode, struct file * filp)
1204 if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1209 EXPORT_SYMBOL(generic_file_open);
1212 * This is used by subsystems that don't want seekable
1215 int nonseekable_open(struct inode *inode, struct file *filp)
1217 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1221 EXPORT_SYMBOL(nonseekable_open);