4 * Copyright (C) 1991, 1992 Linus Torvalds
7 #include <linux/string.h>
9 #include <linux/file.h>
10 #include <linux/smp_lock.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/security.h>
20 #include <linux/mount.h>
21 #include <linux/vfs.h>
22 #include <linux/fcntl.h>
23 #include <asm/uaccess.h>
25 #include <linux/personality.h>
26 #include <linux/pagemap.h>
27 #include <linux/syscalls.h>
28 #include <linux/rcupdate.h>
29 #include <linux/audit.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
.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
.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 mutex_lock(&dentry
->d_inode
->i_mutex
);
215 err
= notify_change(dentry
, &newattrs
);
216 mutex_unlock(&dentry
->d_inode
->i_mutex
);
220 static long do_sys_truncate(const char __user
* path
, loff_t length
)
223 struct inode
* inode
;
227 if (length
< 0) /* sorry, but loff_t says... */
230 error
= user_path_walk(path
, &nd
);
233 inode
= nd
.dentry
->d_inode
;
235 /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
237 if (S_ISDIR(inode
->i_mode
))
241 if (!S_ISREG(inode
->i_mode
))
244 error
= vfs_permission(&nd
, MAY_WRITE
);
249 if (IS_RDONLY(inode
))
253 if (IS_IMMUTABLE(inode
) || IS_APPEND(inode
))
257 * Make sure that there are no leases.
259 error
= break_lease(inode
, FMODE_WRITE
);
263 error
= get_write_access(inode
);
267 error
= locks_verify_truncate(inode
, NULL
, length
);
270 error
= do_truncate(nd
.dentry
, length
, 0, NULL
);
272 put_write_access(inode
);
280 asmlinkage
long sys_truncate(const char __user
* path
, unsigned long length
)
282 /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */
283 return do_sys_truncate(path
, (long)length
);
286 static long do_sys_ftruncate(unsigned int fd
, loff_t length
, int small
)
288 struct inode
* inode
;
289 struct dentry
*dentry
;
301 /* explicitly opened as large or we are on 64-bit box */
302 if (file
->f_flags
& O_LARGEFILE
)
305 dentry
= file
->f_path
.dentry
;
306 inode
= dentry
->d_inode
;
308 if (!S_ISREG(inode
->i_mode
) || !(file
->f_mode
& FMODE_WRITE
))
312 /* Cannot ftruncate over 2^31 bytes without large file support */
313 if (small
&& length
> MAX_NON_LFS
)
317 if (IS_APPEND(inode
))
320 error
= locks_verify_truncate(inode
, file
, length
);
322 error
= do_truncate(dentry
, length
, ATTR_MTIME
|ATTR_CTIME
, file
);
329 asmlinkage
long sys_ftruncate(unsigned int fd
, unsigned long length
)
331 long ret
= do_sys_ftruncate(fd
, length
, 1);
332 /* avoid REGPARM breakage on x86: */
333 prevent_tail_call(ret
);
337 /* LFS versions of truncate are only needed on 32 bit machines */
338 #if BITS_PER_LONG == 32
339 asmlinkage
long sys_truncate64(const char __user
* path
, loff_t length
)
341 return do_sys_truncate(path
, length
);
344 asmlinkage
long sys_ftruncate64(unsigned int fd
, loff_t length
)
346 long ret
= do_sys_ftruncate(fd
, length
, 0);
347 /* avoid REGPARM breakage on x86: */
348 prevent_tail_call(ret
);
354 * access() needs to use the real uid/gid, not the effective uid/gid.
355 * We do this by temporarily clearing all FS-related capabilities and
356 * switching the fsuid/fsgid around to the real ones.
358 asmlinkage
long sys_faccessat(int dfd
, const char __user
*filename
, int mode
)
361 int old_fsuid
, old_fsgid
;
362 kernel_cap_t old_cap
;
365 if (mode
& ~S_IRWXO
) /* where's F_OK, X_OK, W_OK, R_OK? */
368 old_fsuid
= current
->fsuid
;
369 old_fsgid
= current
->fsgid
;
370 old_cap
= current
->cap_effective
;
372 current
->fsuid
= current
->uid
;
373 current
->fsgid
= current
->gid
;
376 * Clear the capabilities if we switch to a non-root user
378 * FIXME: There is a race here against sys_capset. The
379 * capabilities can change yet we will restore the old
380 * value below. We should hold task_capabilities_lock,
381 * but we cannot because user_path_walk can sleep.
384 cap_clear(current
->cap_effective
);
386 current
->cap_effective
= current
->cap_permitted
;
388 res
= __user_walk_fd(dfd
, filename
, LOOKUP_FOLLOW
|LOOKUP_ACCESS
, &nd
);
392 res
= vfs_permission(&nd
, mode
);
393 /* SuS v2 requires we report a read only fs too */
394 if(res
|| !(mode
& S_IWOTH
) ||
395 special_file(nd
.dentry
->d_inode
->i_mode
))
396 goto out_path_release
;
398 if(IS_RDONLY(nd
.dentry
->d_inode
))
404 current
->fsuid
= old_fsuid
;
405 current
->fsgid
= old_fsgid
;
406 current
->cap_effective
= old_cap
;
411 asmlinkage
long sys_access(const char __user
*filename
, int mode
)
413 return sys_faccessat(AT_FDCWD
, filename
, mode
);
416 asmlinkage
long sys_chdir(const char __user
* filename
)
421 error
= __user_walk(filename
,
422 LOOKUP_FOLLOW
|LOOKUP_DIRECTORY
|LOOKUP_CHDIR
, &nd
);
426 error
= vfs_permission(&nd
, MAY_EXEC
);
430 set_fs_pwd(current
->fs
, nd
.mnt
, nd
.dentry
);
438 asmlinkage
long sys_fchdir(unsigned int fd
)
441 struct dentry
*dentry
;
443 struct vfsmount
*mnt
;
451 dentry
= file
->f_path
.dentry
;
452 mnt
= file
->f_path
.mnt
;
453 inode
= dentry
->d_inode
;
456 if (!S_ISDIR(inode
->i_mode
))
459 error
= file_permission(file
, MAY_EXEC
);
461 set_fs_pwd(current
->fs
, mnt
, dentry
);
468 asmlinkage
long sys_chroot(const char __user
* filename
)
473 error
= __user_walk(filename
, LOOKUP_FOLLOW
| LOOKUP_DIRECTORY
| LOOKUP_NOALT
, &nd
);
477 error
= vfs_permission(&nd
, MAY_EXEC
);
482 if (!capable(CAP_SYS_CHROOT
))
485 set_fs_root(current
->fs
, nd
.mnt
, nd
.dentry
);
494 asmlinkage
long sys_fchmod(unsigned int fd
, mode_t mode
)
496 struct inode
* inode
;
497 struct dentry
* dentry
;
500 struct iattr newattrs
;
506 dentry
= file
->f_path
.dentry
;
507 inode
= dentry
->d_inode
;
509 audit_inode(NULL
, inode
);
512 if (IS_RDONLY(inode
))
515 if (IS_IMMUTABLE(inode
) || IS_APPEND(inode
))
517 mutex_lock(&inode
->i_mutex
);
518 if (mode
== (mode_t
) -1)
519 mode
= inode
->i_mode
;
520 newattrs
.ia_mode
= (mode
& S_IALLUGO
) | (inode
->i_mode
& ~S_IALLUGO
);
521 newattrs
.ia_valid
= ATTR_MODE
| ATTR_CTIME
;
522 err
= notify_change(dentry
, &newattrs
);
523 mutex_unlock(&inode
->i_mutex
);
531 asmlinkage
long sys_fchmodat(int dfd
, const char __user
*filename
,
535 struct inode
* inode
;
537 struct iattr newattrs
;
539 error
= __user_walk_fd(dfd
, filename
, LOOKUP_FOLLOW
, &nd
);
542 inode
= nd
.dentry
->d_inode
;
545 if (IS_RDONLY(inode
))
549 if (IS_IMMUTABLE(inode
) || IS_APPEND(inode
))
552 mutex_lock(&inode
->i_mutex
);
553 if (mode
== (mode_t
) -1)
554 mode
= inode
->i_mode
;
555 newattrs
.ia_mode
= (mode
& S_IALLUGO
) | (inode
->i_mode
& ~S_IALLUGO
);
556 newattrs
.ia_valid
= ATTR_MODE
| ATTR_CTIME
;
557 error
= notify_change(nd
.dentry
, &newattrs
);
558 mutex_unlock(&inode
->i_mutex
);
566 asmlinkage
long sys_chmod(const char __user
*filename
, mode_t mode
)
568 return sys_fchmodat(AT_FDCWD
, filename
, mode
);
571 static int chown_common(struct dentry
* dentry
, uid_t user
, gid_t group
)
573 struct inode
* inode
;
575 struct iattr newattrs
;
578 if (!(inode
= dentry
->d_inode
)) {
579 printk(KERN_ERR
"chown_common: NULL inode\n");
583 if (IS_RDONLY(inode
))
586 if (IS_IMMUTABLE(inode
) || IS_APPEND(inode
))
588 newattrs
.ia_valid
= ATTR_CTIME
;
589 if (user
!= (uid_t
) -1) {
590 newattrs
.ia_valid
|= ATTR_UID
;
591 newattrs
.ia_uid
= user
;
593 if (group
!= (gid_t
) -1) {
594 newattrs
.ia_valid
|= ATTR_GID
;
595 newattrs
.ia_gid
= group
;
597 if (!S_ISDIR(inode
->i_mode
))
598 newattrs
.ia_valid
|= ATTR_KILL_SUID
|ATTR_KILL_SGID
;
599 mutex_lock(&inode
->i_mutex
);
600 error
= notify_change(dentry
, &newattrs
);
601 mutex_unlock(&inode
->i_mutex
);
606 asmlinkage
long sys_chown(const char __user
* filename
, uid_t user
, gid_t group
)
611 error
= user_path_walk(filename
, &nd
);
614 error
= chown_common(nd
.dentry
, user
, group
);
620 asmlinkage
long sys_fchownat(int dfd
, const char __user
*filename
, uid_t user
,
621 gid_t group
, int flag
)
627 if ((flag
& ~AT_SYMLINK_NOFOLLOW
) != 0)
630 follow
= (flag
& AT_SYMLINK_NOFOLLOW
) ? 0 : LOOKUP_FOLLOW
;
631 error
= __user_walk_fd(dfd
, filename
, follow
, &nd
);
634 error
= chown_common(nd
.dentry
, user
, group
);
640 asmlinkage
long sys_lchown(const char __user
* filename
, uid_t user
, gid_t group
)
645 error
= user_path_walk_link(filename
, &nd
);
648 error
= chown_common(nd
.dentry
, user
, group
);
655 asmlinkage
long sys_fchown(unsigned int fd
, uid_t user
, gid_t group
)
659 struct dentry
* dentry
;
665 dentry
= file
->f_path
.dentry
;
666 audit_inode(NULL
, dentry
->d_inode
);
667 error
= chown_common(dentry
, user
, group
);
673 static struct file
*__dentry_open(struct dentry
*dentry
, struct vfsmount
*mnt
,
674 int flags
, struct file
*f
,
675 int (*open
)(struct inode
*, struct file
*))
681 f
->f_mode
= ((flags
+1) & O_ACCMODE
) | FMODE_LSEEK
|
682 FMODE_PREAD
| FMODE_PWRITE
;
683 inode
= dentry
->d_inode
;
684 if (f
->f_mode
& FMODE_WRITE
) {
685 error
= get_write_access(inode
);
690 f
->f_mapping
= inode
->i_mapping
;
691 f
->f_path
.dentry
= dentry
;
694 f
->f_op
= fops_get(inode
->i_fop
);
695 file_move(f
, &inode
->i_sb
->s_files
);
697 if (!open
&& f
->f_op
)
698 open
= f
->f_op
->open
;
700 error
= open(inode
, f
);
705 f
->f_flags
&= ~(O_CREAT
| O_EXCL
| O_NOCTTY
| O_TRUNC
);
707 file_ra_state_init(&f
->f_ra
, f
->f_mapping
->host
->i_mapping
);
709 /* NB: we're sure to have correct a_ops only after f_op->open */
710 if (f
->f_flags
& O_DIRECT
) {
711 if (!f
->f_mapping
->a_ops
||
712 ((!f
->f_mapping
->a_ops
->direct_IO
) &&
713 (!f
->f_mapping
->a_ops
->get_xip_page
))) {
715 f
= ERR_PTR(-EINVAL
);
723 if (f
->f_mode
& FMODE_WRITE
)
724 put_write_access(inode
);
726 f
->f_path
.dentry
= NULL
;
727 f
->f_path
.mnt
= NULL
;
732 return ERR_PTR(error
);
736 * Note that while the flag value (low two bits) for sys_open means:
742 * 00 - no permissions needed
743 * 01 - read-permission
744 * 10 - write-permission
746 * for the internal routines (ie open_namei()/follow_link() etc). 00 is
749 static struct file
*do_filp_open(int dfd
, const char *filename
, int flags
,
752 int namei_flags
, error
;
756 if ((namei_flags
+1) & O_ACCMODE
)
759 error
= open_namei(dfd
, filename
, namei_flags
, mode
, &nd
);
761 return nameidata_to_filp(&nd
, flags
);
763 return ERR_PTR(error
);
766 struct file
*filp_open(const char *filename
, int flags
, int mode
)
768 return do_filp_open(AT_FDCWD
, filename
, flags
, mode
);
770 EXPORT_SYMBOL(filp_open
);
773 * lookup_instantiate_filp - instantiates the open intent filp
774 * @nd: pointer to nameidata
775 * @dentry: pointer to dentry
776 * @open: open callback
778 * Helper for filesystems that want to use lookup open intents and pass back
779 * a fully instantiated struct file to the caller.
780 * This function is meant to be called from within a filesystem's
782 * Beware of calling it for non-regular files! Those ->open methods might block
783 * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo,
784 * leading to a deadlock, as nobody can open that fifo anymore, because
785 * another process to open fifo will block on locked parent when doing lookup).
786 * Note that in case of error, nd->intent.open.file is destroyed, but the
787 * path information remains valid.
788 * If the open callback is set to NULL, then the standard f_op->open()
789 * filesystem callback is substituted.
791 struct file
*lookup_instantiate_filp(struct nameidata
*nd
, struct dentry
*dentry
,
792 int (*open
)(struct inode
*, struct file
*))
794 if (IS_ERR(nd
->intent
.open
.file
))
798 nd
->intent
.open
.file
= __dentry_open(dget(dentry
), mntget(nd
->mnt
),
799 nd
->intent
.open
.flags
- 1,
800 nd
->intent
.open
.file
,
803 return nd
->intent
.open
.file
;
805 release_open_intent(nd
);
806 nd
->intent
.open
.file
= (struct file
*)dentry
;
809 EXPORT_SYMBOL_GPL(lookup_instantiate_filp
);
812 * nameidata_to_filp - convert a nameidata to an open filp.
813 * @nd: pointer to nameidata
816 * Note that this function destroys the original nameidata
818 struct file
*nameidata_to_filp(struct nameidata
*nd
, int flags
)
822 /* Pick up the filp from the open intent */
823 filp
= nd
->intent
.open
.file
;
824 /* Has the filesystem initialised the file for us? */
825 if (filp
->f_path
.dentry
== NULL
)
826 filp
= __dentry_open(nd
->dentry
, nd
->mnt
, flags
, filp
, NULL
);
833 * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
836 struct file
*dentry_open(struct dentry
*dentry
, struct vfsmount
*mnt
, int flags
)
842 f
= get_empty_filp();
846 return ERR_PTR(error
);
849 return __dentry_open(dentry
, mnt
, flags
, f
, NULL
);
851 EXPORT_SYMBOL(dentry_open
);
854 * Find an empty file descriptor entry, and mark it busy.
856 int get_unused_fd(void)
858 struct files_struct
* files
= current
->files
;
863 spin_lock(&files
->file_lock
);
866 fdt
= files_fdtable(files
);
867 fd
= find_next_zero_bit(fdt
->open_fds
->fds_bits
,
872 * N.B. For clone tasks sharing a files structure, this test
873 * will limit the total number of files that can be opened.
875 if (fd
>= current
->signal
->rlim
[RLIMIT_NOFILE
].rlim_cur
)
878 /* Do we need to expand the fd array or fd set? */
879 error
= expand_files(files
, fd
);
885 * If we needed to expand the fs array we
886 * might have blocked - try again.
892 FD_SET(fd
, fdt
->open_fds
);
893 FD_CLR(fd
, fdt
->close_on_exec
);
894 files
->next_fd
= fd
+ 1;
897 if (fdt
->fd
[fd
] != NULL
) {
898 printk(KERN_WARNING
"get_unused_fd: slot %d not NULL!\n", fd
);
905 spin_unlock(&files
->file_lock
);
909 EXPORT_SYMBOL(get_unused_fd
);
911 static void __put_unused_fd(struct files_struct
*files
, unsigned int fd
)
913 struct fdtable
*fdt
= files_fdtable(files
);
914 __FD_CLR(fd
, fdt
->open_fds
);
915 if (fd
< files
->next_fd
)
919 void fastcall
put_unused_fd(unsigned int fd
)
921 struct files_struct
*files
= current
->files
;
922 spin_lock(&files
->file_lock
);
923 __put_unused_fd(files
, fd
);
924 spin_unlock(&files
->file_lock
);
927 EXPORT_SYMBOL(put_unused_fd
);
930 * Install a file pointer in the fd array.
932 * The VFS is full of places where we drop the files lock between
933 * setting the open_fds bitmap and installing the file in the file
934 * array. At any such point, we are vulnerable to a dup2() race
935 * installing a file in the array before us. We need to detect this and
936 * fput() the struct file we are about to overwrite in this case.
938 * It should never happen - if we allow dup2() do it, _really_ bad things
942 void fastcall
fd_install(unsigned int fd
, struct file
* file
)
944 struct files_struct
*files
= current
->files
;
946 spin_lock(&files
->file_lock
);
947 fdt
= files_fdtable(files
);
948 BUG_ON(fdt
->fd
[fd
] != NULL
);
949 rcu_assign_pointer(fdt
->fd
[fd
], file
);
950 spin_unlock(&files
->file_lock
);
953 EXPORT_SYMBOL(fd_install
);
955 long do_sys_open(int dfd
, const char __user
*filename
, int flags
, int mode
)
957 char *tmp
= getname(filename
);
958 int fd
= PTR_ERR(tmp
);
961 fd
= get_unused_fd();
963 struct file
*f
= do_filp_open(dfd
, tmp
, flags
, mode
);
968 fsnotify_open(f
->f_path
.dentry
);
977 asmlinkage
long sys_open(const char __user
*filename
, int flags
, int mode
)
981 if (force_o_largefile())
982 flags
|= O_LARGEFILE
;
984 ret
= do_sys_open(AT_FDCWD
, filename
, flags
, mode
);
985 /* avoid REGPARM breakage on x86: */
986 prevent_tail_call(ret
);
989 EXPORT_SYMBOL_GPL(sys_open
);
991 asmlinkage
long sys_openat(int dfd
, const char __user
*filename
, int flags
,
996 if (force_o_largefile())
997 flags
|= O_LARGEFILE
;
999 ret
= do_sys_open(dfd
, filename
, flags
, mode
);
1000 /* avoid REGPARM breakage on x86: */
1001 prevent_tail_call(ret
);
1008 * For backward compatibility? Maybe this should be moved
1009 * into arch/i386 instead?
1011 asmlinkage
long sys_creat(const char __user
* pathname
, int mode
)
1013 return sys_open(pathname
, O_CREAT
| O_WRONLY
| O_TRUNC
, mode
);
1019 * "id" is the POSIX thread ID. We use the
1020 * files pointer for this..
1022 int filp_close(struct file
*filp
, fl_owner_t id
)
1026 if (!file_count(filp
)) {
1027 printk(KERN_ERR
"VFS: Close: file count is 0\n");
1031 if (filp
->f_op
&& filp
->f_op
->flush
)
1032 retval
= filp
->f_op
->flush(filp
, id
);
1034 dnotify_flush(filp
, id
);
1035 locks_remove_posix(filp
, id
);
1040 EXPORT_SYMBOL(filp_close
);
1043 * Careful here! We test whether the file pointer is NULL before
1044 * releasing the fd. This ensures that one clone task can't release
1045 * an fd while another clone is opening it.
1047 asmlinkage
long sys_close(unsigned int fd
)
1050 struct files_struct
*files
= current
->files
;
1051 struct fdtable
*fdt
;
1054 spin_lock(&files
->file_lock
);
1055 fdt
= files_fdtable(files
);
1056 if (fd
>= fdt
->max_fds
)
1061 rcu_assign_pointer(fdt
->fd
[fd
], NULL
);
1062 FD_CLR(fd
, fdt
->close_on_exec
);
1063 __put_unused_fd(files
, fd
);
1064 spin_unlock(&files
->file_lock
);
1065 retval
= filp_close(filp
, files
);
1067 /* can't restart close syscall because file table entry was cleared */
1068 if (unlikely(retval
== -ERESTARTSYS
||
1069 retval
== -ERESTARTNOINTR
||
1070 retval
== -ERESTARTNOHAND
||
1071 retval
== -ERESTART_RESTARTBLOCK
))
1077 spin_unlock(&files
->file_lock
);
1081 EXPORT_SYMBOL(sys_close
);
1084 * This routine simulates a hangup on the tty, to arrange that users
1085 * are given clean terminals at login time.
1087 asmlinkage
long sys_vhangup(void)
1089 if (capable(CAP_SYS_TTY_CONFIG
)) {
1090 /* XXX: this needs locking */
1091 tty_vhangup(current
->signal
->tty
);
1098 * Called when an inode is about to be open.
1099 * We use this to disallow opening large files on 32bit systems if
1100 * the caller didn't specify O_LARGEFILE. On 64bit systems we force
1101 * on this flag in sys_open.
1103 int generic_file_open(struct inode
* inode
, struct file
* filp
)
1105 if (!(filp
->f_flags
& O_LARGEFILE
) && i_size_read(inode
) > MAX_NON_LFS
)
1110 EXPORT_SYMBOL(generic_file_open
);
1113 * This is used by subsystems that don't want seekable
1116 int nonseekable_open(struct inode
*inode
, struct file
*filp
)
1118 filp
->f_mode
&= ~(FMODE_LSEEK
| FMODE_PREAD
| FMODE_PWRITE
);
1122 EXPORT_SYMBOL(nonseekable_open
);