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>
30 int vfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
36 if (dentry
->d_sb
->s_op
->statfs
) {
37 memset(buf
, 0, sizeof(*buf
));
38 retval
= security_sb_statfs(dentry
);
41 retval
= dentry
->d_sb
->s_op
->statfs(dentry
, buf
);
42 if (retval
== 0 && buf
->f_frsize
== 0)
43 buf
->f_frsize
= buf
->f_bsize
;
49 EXPORT_SYMBOL(vfs_statfs
);
51 static int vfs_statfs_native(struct dentry
*dentry
, struct statfs
*buf
)
56 retval
= vfs_statfs(dentry
, &st
);
60 if (sizeof(*buf
) == sizeof(st
))
61 memcpy(buf
, &st
, sizeof(st
));
63 if (sizeof buf
->f_blocks
== 4) {
64 if ((st
.f_blocks
| st
.f_bfree
| st
.f_bavail
) &
65 0xffffffff00000000ULL
)
68 * f_files and f_ffree may be -1; it's okay to stuff
71 if (st
.f_files
!= -1 &&
72 (st
.f_files
& 0xffffffff00000000ULL
))
74 if (st
.f_ffree
!= -1 &&
75 (st
.f_ffree
& 0xffffffff00000000ULL
))
79 buf
->f_type
= st
.f_type
;
80 buf
->f_bsize
= st
.f_bsize
;
81 buf
->f_blocks
= st
.f_blocks
;
82 buf
->f_bfree
= st
.f_bfree
;
83 buf
->f_bavail
= st
.f_bavail
;
84 buf
->f_files
= st
.f_files
;
85 buf
->f_ffree
= st
.f_ffree
;
86 buf
->f_fsid
= st
.f_fsid
;
87 buf
->f_namelen
= st
.f_namelen
;
88 buf
->f_frsize
= st
.f_frsize
;
89 memset(buf
->f_spare
, 0, sizeof(buf
->f_spare
));
94 static int vfs_statfs64(struct dentry
*dentry
, struct statfs64
*buf
)
99 retval
= vfs_statfs(dentry
, &st
);
103 if (sizeof(*buf
) == sizeof(st
))
104 memcpy(buf
, &st
, sizeof(st
));
106 buf
->f_type
= st
.f_type
;
107 buf
->f_bsize
= st
.f_bsize
;
108 buf
->f_blocks
= st
.f_blocks
;
109 buf
->f_bfree
= st
.f_bfree
;
110 buf
->f_bavail
= st
.f_bavail
;
111 buf
->f_files
= st
.f_files
;
112 buf
->f_ffree
= st
.f_ffree
;
113 buf
->f_fsid
= st
.f_fsid
;
114 buf
->f_namelen
= st
.f_namelen
;
115 buf
->f_frsize
= st
.f_frsize
;
116 memset(buf
->f_spare
, 0, sizeof(buf
->f_spare
));
121 asmlinkage
long sys_statfs(const char __user
* path
, struct statfs __user
* buf
)
126 error
= user_path_walk(path
, &nd
);
129 error
= vfs_statfs_native(nd
.dentry
, &tmp
);
130 if (!error
&& copy_to_user(buf
, &tmp
, sizeof(tmp
)))
138 asmlinkage
long sys_statfs64(const char __user
*path
, size_t sz
, struct statfs64 __user
*buf
)
143 if (sz
!= sizeof(*buf
))
145 error
= user_path_walk(path
, &nd
);
148 error
= vfs_statfs64(nd
.dentry
, &tmp
);
149 if (!error
&& copy_to_user(buf
, &tmp
, sizeof(tmp
)))
157 asmlinkage
long sys_fstatfs(unsigned int fd
, struct statfs __user
* buf
)
167 error
= vfs_statfs_native(file
->f_path
.dentry
, &tmp
);
168 if (!error
&& copy_to_user(buf
, &tmp
, sizeof(tmp
)))
175 asmlinkage
long sys_fstatfs64(unsigned int fd
, size_t sz
, struct statfs64 __user
*buf
)
181 if (sz
!= sizeof(*buf
))
188 error
= vfs_statfs64(file
->f_path
.dentry
, &tmp
);
189 if (!error
&& copy_to_user(buf
, &tmp
, sizeof(tmp
)))
196 int do_truncate(struct dentry
*dentry
, loff_t length
, unsigned int time_attrs
,
200 struct iattr newattrs
;
202 /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */
206 newattrs
.ia_size
= length
;
207 newattrs
.ia_valid
= ATTR_SIZE
| time_attrs
;
209 newattrs
.ia_file
= filp
;
210 newattrs
.ia_valid
|= ATTR_FILE
;
213 /* Remove suid/sgid on truncate too */
214 newattrs
.ia_valid
|= should_remove_suid(dentry
);
216 mutex_lock(&dentry
->d_inode
->i_mutex
);
217 err
= notify_change(dentry
, &newattrs
);
218 mutex_unlock(&dentry
->d_inode
->i_mutex
);
222 static long do_sys_truncate(const char __user
* path
, loff_t length
)
225 struct inode
* inode
;
229 if (length
< 0) /* sorry, but loff_t says... */
232 error
= user_path_walk(path
, &nd
);
235 inode
= nd
.dentry
->d_inode
;
237 /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
239 if (S_ISDIR(inode
->i_mode
))
243 if (!S_ISREG(inode
->i_mode
))
246 error
= vfs_permission(&nd
, MAY_WRITE
);
251 if (IS_RDONLY(inode
))
255 if (IS_IMMUTABLE(inode
) || IS_APPEND(inode
))
259 * Make sure that there are no leases.
261 error
= break_lease(inode
, FMODE_WRITE
);
265 error
= get_write_access(inode
);
269 error
= locks_verify_truncate(inode
, NULL
, length
);
272 error
= do_truncate(nd
.dentry
, length
, 0, NULL
);
274 put_write_access(inode
);
282 asmlinkage
long sys_truncate(const char __user
* path
, unsigned long length
)
284 /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */
285 return do_sys_truncate(path
, (long)length
);
288 static long do_sys_ftruncate(unsigned int fd
, loff_t length
, int small
)
290 struct inode
* inode
;
291 struct dentry
*dentry
;
303 /* explicitly opened as large or we are on 64-bit box */
304 if (file
->f_flags
& O_LARGEFILE
)
307 dentry
= file
->f_path
.dentry
;
308 inode
= dentry
->d_inode
;
310 if (!S_ISREG(inode
->i_mode
) || !(file
->f_mode
& FMODE_WRITE
))
314 /* Cannot ftruncate over 2^31 bytes without large file support */
315 if (small
&& length
> MAX_NON_LFS
)
319 if (IS_APPEND(inode
))
322 error
= locks_verify_truncate(inode
, file
, length
);
324 error
= do_truncate(dentry
, length
, ATTR_MTIME
|ATTR_CTIME
, file
);
331 asmlinkage
long sys_ftruncate(unsigned int fd
, unsigned long length
)
333 long ret
= do_sys_ftruncate(fd
, length
, 1);
334 /* avoid REGPARM breakage on x86: */
335 prevent_tail_call(ret
);
339 /* LFS versions of truncate are only needed on 32 bit machines */
340 #if BITS_PER_LONG == 32
341 asmlinkage
long sys_truncate64(const char __user
* path
, loff_t length
)
343 return do_sys_truncate(path
, length
);
346 asmlinkage
long sys_ftruncate64(unsigned int fd
, loff_t length
)
348 long ret
= do_sys_ftruncate(fd
, length
, 0);
349 /* avoid REGPARM breakage on x86: */
350 prevent_tail_call(ret
);
356 * access() needs to use the real uid/gid, not the effective uid/gid.
357 * We do this by temporarily clearing all FS-related capabilities and
358 * switching the fsuid/fsgid around to the real ones.
360 asmlinkage
long sys_faccessat(int dfd
, const char __user
*filename
, int mode
)
363 int old_fsuid
, old_fsgid
;
364 kernel_cap_t old_cap
;
367 if (mode
& ~S_IRWXO
) /* where's F_OK, X_OK, W_OK, R_OK? */
370 old_fsuid
= current
->fsuid
;
371 old_fsgid
= current
->fsgid
;
372 old_cap
= current
->cap_effective
;
374 current
->fsuid
= current
->uid
;
375 current
->fsgid
= current
->gid
;
378 * Clear the capabilities if we switch to a non-root user
380 * FIXME: There is a race here against sys_capset. The
381 * capabilities can change yet we will restore the old
382 * value below. We should hold task_capabilities_lock,
383 * but we cannot because user_path_walk can sleep.
386 cap_clear(current
->cap_effective
);
388 current
->cap_effective
= current
->cap_permitted
;
390 res
= __user_walk_fd(dfd
, filename
, LOOKUP_FOLLOW
|LOOKUP_ACCESS
, &nd
);
394 res
= vfs_permission(&nd
, mode
);
395 /* SuS v2 requires we report a read only fs too */
396 if(res
|| !(mode
& S_IWOTH
) ||
397 special_file(nd
.dentry
->d_inode
->i_mode
))
398 goto out_path_release
;
400 if(IS_RDONLY(nd
.dentry
->d_inode
))
406 current
->fsuid
= old_fsuid
;
407 current
->fsgid
= old_fsgid
;
408 current
->cap_effective
= old_cap
;
413 asmlinkage
long sys_access(const char __user
*filename
, int mode
)
415 return sys_faccessat(AT_FDCWD
, filename
, mode
);
418 asmlinkage
long sys_chdir(const char __user
* filename
)
423 error
= __user_walk(filename
,
424 LOOKUP_FOLLOW
|LOOKUP_DIRECTORY
|LOOKUP_CHDIR
, &nd
);
428 error
= vfs_permission(&nd
, MAY_EXEC
);
432 set_fs_pwd(current
->fs
, nd
.mnt
, nd
.dentry
);
440 asmlinkage
long sys_fchdir(unsigned int fd
)
443 struct dentry
*dentry
;
445 struct vfsmount
*mnt
;
453 dentry
= file
->f_path
.dentry
;
454 mnt
= file
->f_path
.mnt
;
455 inode
= dentry
->d_inode
;
458 if (!S_ISDIR(inode
->i_mode
))
461 error
= file_permission(file
, MAY_EXEC
);
463 set_fs_pwd(current
->fs
, mnt
, dentry
);
470 asmlinkage
long sys_chroot(const char __user
* filename
)
475 error
= __user_walk(filename
, LOOKUP_FOLLOW
| LOOKUP_DIRECTORY
| LOOKUP_NOALT
, &nd
);
479 error
= vfs_permission(&nd
, MAY_EXEC
);
484 if (!capable(CAP_SYS_CHROOT
))
487 set_fs_root(current
->fs
, nd
.mnt
, nd
.dentry
);
496 asmlinkage
long sys_fchmod(unsigned int fd
, mode_t mode
)
498 struct inode
* inode
;
499 struct dentry
* dentry
;
502 struct iattr newattrs
;
508 dentry
= file
->f_path
.dentry
;
509 inode
= dentry
->d_inode
;
511 audit_inode(NULL
, inode
);
514 if (IS_RDONLY(inode
))
517 if (IS_IMMUTABLE(inode
) || IS_APPEND(inode
))
519 mutex_lock(&inode
->i_mutex
);
520 if (mode
== (mode_t
) -1)
521 mode
= inode
->i_mode
;
522 newattrs
.ia_mode
= (mode
& S_IALLUGO
) | (inode
->i_mode
& ~S_IALLUGO
);
523 newattrs
.ia_valid
= ATTR_MODE
| ATTR_CTIME
;
524 err
= notify_change(dentry
, &newattrs
);
525 mutex_unlock(&inode
->i_mutex
);
533 asmlinkage
long sys_fchmodat(int dfd
, const char __user
*filename
,
537 struct inode
* inode
;
539 struct iattr newattrs
;
541 error
= __user_walk_fd(dfd
, filename
, LOOKUP_FOLLOW
, &nd
);
544 inode
= nd
.dentry
->d_inode
;
547 if (IS_RDONLY(inode
))
551 if (IS_IMMUTABLE(inode
) || IS_APPEND(inode
))
554 mutex_lock(&inode
->i_mutex
);
555 if (mode
== (mode_t
) -1)
556 mode
= inode
->i_mode
;
557 newattrs
.ia_mode
= (mode
& S_IALLUGO
) | (inode
->i_mode
& ~S_IALLUGO
);
558 newattrs
.ia_valid
= ATTR_MODE
| ATTR_CTIME
;
559 error
= notify_change(nd
.dentry
, &newattrs
);
560 mutex_unlock(&inode
->i_mutex
);
568 asmlinkage
long sys_chmod(const char __user
*filename
, mode_t mode
)
570 return sys_fchmodat(AT_FDCWD
, filename
, mode
);
573 static int chown_common(struct dentry
* dentry
, uid_t user
, gid_t group
)
575 struct inode
* inode
;
577 struct iattr newattrs
;
580 if (!(inode
= dentry
->d_inode
)) {
581 printk(KERN_ERR
"chown_common: NULL inode\n");
585 if (IS_RDONLY(inode
))
588 if (IS_IMMUTABLE(inode
) || IS_APPEND(inode
))
590 newattrs
.ia_valid
= ATTR_CTIME
;
591 if (user
!= (uid_t
) -1) {
592 newattrs
.ia_valid
|= ATTR_UID
;
593 newattrs
.ia_uid
= user
;
595 if (group
!= (gid_t
) -1) {
596 newattrs
.ia_valid
|= ATTR_GID
;
597 newattrs
.ia_gid
= group
;
599 if (!S_ISDIR(inode
->i_mode
))
600 newattrs
.ia_valid
|= ATTR_KILL_SUID
|ATTR_KILL_SGID
;
601 mutex_lock(&inode
->i_mutex
);
602 error
= notify_change(dentry
, &newattrs
);
603 mutex_unlock(&inode
->i_mutex
);
608 asmlinkage
long sys_chown(const char __user
* filename
, uid_t user
, gid_t group
)
613 error
= user_path_walk(filename
, &nd
);
616 error
= chown_common(nd
.dentry
, user
, group
);
622 asmlinkage
long sys_fchownat(int dfd
, const char __user
*filename
, uid_t user
,
623 gid_t group
, int flag
)
629 if ((flag
& ~AT_SYMLINK_NOFOLLOW
) != 0)
632 follow
= (flag
& AT_SYMLINK_NOFOLLOW
) ? 0 : LOOKUP_FOLLOW
;
633 error
= __user_walk_fd(dfd
, filename
, follow
, &nd
);
636 error
= chown_common(nd
.dentry
, user
, group
);
642 asmlinkage
long sys_lchown(const char __user
* filename
, uid_t user
, gid_t group
)
647 error
= user_path_walk_link(filename
, &nd
);
650 error
= chown_common(nd
.dentry
, user
, group
);
657 asmlinkage
long sys_fchown(unsigned int fd
, uid_t user
, gid_t group
)
661 struct dentry
* dentry
;
667 dentry
= file
->f_path
.dentry
;
668 audit_inode(NULL
, dentry
->d_inode
);
669 error
= chown_common(dentry
, user
, group
);
675 static struct file
*__dentry_open(struct dentry
*dentry
, struct vfsmount
*mnt
,
676 int flags
, struct file
*f
,
677 int (*open
)(struct inode
*, struct file
*))
683 f
->f_mode
= ((flags
+1) & O_ACCMODE
) | FMODE_LSEEK
|
684 FMODE_PREAD
| FMODE_PWRITE
;
685 inode
= dentry
->d_inode
;
686 if (f
->f_mode
& FMODE_WRITE
) {
687 error
= get_write_access(inode
);
692 f
->f_mapping
= inode
->i_mapping
;
693 f
->f_path
.dentry
= dentry
;
696 f
->f_op
= fops_get(inode
->i_fop
);
697 file_move(f
, &inode
->i_sb
->s_files
);
699 if (!open
&& f
->f_op
)
700 open
= f
->f_op
->open
;
702 error
= open(inode
, f
);
707 f
->f_flags
&= ~(O_CREAT
| O_EXCL
| O_NOCTTY
| O_TRUNC
);
709 file_ra_state_init(&f
->f_ra
, f
->f_mapping
->host
->i_mapping
);
711 /* NB: we're sure to have correct a_ops only after f_op->open */
712 if (f
->f_flags
& O_DIRECT
) {
713 if (!f
->f_mapping
->a_ops
||
714 ((!f
->f_mapping
->a_ops
->direct_IO
) &&
715 (!f
->f_mapping
->a_ops
->get_xip_page
))) {
717 f
= ERR_PTR(-EINVAL
);
725 if (f
->f_mode
& FMODE_WRITE
)
726 put_write_access(inode
);
728 f
->f_path
.dentry
= NULL
;
729 f
->f_path
.mnt
= NULL
;
734 return ERR_PTR(error
);
738 * Note that while the flag value (low two bits) for sys_open means:
744 * 00 - no permissions needed
745 * 01 - read-permission
746 * 10 - write-permission
748 * for the internal routines (ie open_namei()/follow_link() etc). 00 is
751 static struct file
*do_filp_open(int dfd
, const char *filename
, int flags
,
754 int namei_flags
, error
;
758 if ((namei_flags
+1) & O_ACCMODE
)
761 error
= open_namei(dfd
, filename
, namei_flags
, mode
, &nd
);
763 return nameidata_to_filp(&nd
, flags
);
765 return ERR_PTR(error
);
768 struct file
*filp_open(const char *filename
, int flags
, int mode
)
770 return do_filp_open(AT_FDCWD
, filename
, flags
, mode
);
772 EXPORT_SYMBOL(filp_open
);
775 * lookup_instantiate_filp - instantiates the open intent filp
776 * @nd: pointer to nameidata
777 * @dentry: pointer to dentry
778 * @open: open callback
780 * Helper for filesystems that want to use lookup open intents and pass back
781 * a fully instantiated struct file to the caller.
782 * This function is meant to be called from within a filesystem's
784 * Beware of calling it for non-regular files! Those ->open methods might block
785 * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo,
786 * leading to a deadlock, as nobody can open that fifo anymore, because
787 * another process to open fifo will block on locked parent when doing lookup).
788 * Note that in case of error, nd->intent.open.file is destroyed, but the
789 * path information remains valid.
790 * If the open callback is set to NULL, then the standard f_op->open()
791 * filesystem callback is substituted.
793 struct file
*lookup_instantiate_filp(struct nameidata
*nd
, struct dentry
*dentry
,
794 int (*open
)(struct inode
*, struct file
*))
796 if (IS_ERR(nd
->intent
.open
.file
))
800 nd
->intent
.open
.file
= __dentry_open(dget(dentry
), mntget(nd
->mnt
),
801 nd
->intent
.open
.flags
- 1,
802 nd
->intent
.open
.file
,
805 return nd
->intent
.open
.file
;
807 release_open_intent(nd
);
808 nd
->intent
.open
.file
= (struct file
*)dentry
;
811 EXPORT_SYMBOL_GPL(lookup_instantiate_filp
);
814 * nameidata_to_filp - convert a nameidata to an open filp.
815 * @nd: pointer to nameidata
818 * Note that this function destroys the original nameidata
820 struct file
*nameidata_to_filp(struct nameidata
*nd
, int flags
)
824 /* Pick up the filp from the open intent */
825 filp
= nd
->intent
.open
.file
;
826 /* Has the filesystem initialised the file for us? */
827 if (filp
->f_path
.dentry
== NULL
)
828 filp
= __dentry_open(nd
->dentry
, nd
->mnt
, flags
, filp
, NULL
);
835 * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
838 struct file
*dentry_open(struct dentry
*dentry
, struct vfsmount
*mnt
, int flags
)
844 f
= get_empty_filp();
848 return ERR_PTR(error
);
851 return __dentry_open(dentry
, mnt
, flags
, f
, NULL
);
853 EXPORT_SYMBOL(dentry_open
);
856 * Find an empty file descriptor entry, and mark it busy.
858 int get_unused_fd(void)
860 struct files_struct
* files
= current
->files
;
865 spin_lock(&files
->file_lock
);
868 fdt
= files_fdtable(files
);
869 fd
= find_next_zero_bit(fdt
->open_fds
->fds_bits
, fdt
->max_fds
,
873 * N.B. For clone tasks sharing a files structure, this test
874 * will limit the total number of files that can be opened.
876 if (fd
>= current
->signal
->rlim
[RLIMIT_NOFILE
].rlim_cur
)
879 /* Do we need to expand the fd array or fd set? */
880 error
= expand_files(files
, fd
);
886 * If we needed to expand the fs array we
887 * might have blocked - try again.
893 FD_SET(fd
, fdt
->open_fds
);
894 FD_CLR(fd
, fdt
->close_on_exec
);
895 files
->next_fd
= fd
+ 1;
898 if (fdt
->fd
[fd
] != NULL
) {
899 printk(KERN_WARNING
"get_unused_fd: slot %d not NULL!\n", fd
);
906 spin_unlock(&files
->file_lock
);
910 EXPORT_SYMBOL(get_unused_fd
);
912 static void __put_unused_fd(struct files_struct
*files
, unsigned int fd
)
914 struct fdtable
*fdt
= files_fdtable(files
);
915 __FD_CLR(fd
, fdt
->open_fds
);
916 if (fd
< files
->next_fd
)
920 void fastcall
put_unused_fd(unsigned int fd
)
922 struct files_struct
*files
= current
->files
;
923 spin_lock(&files
->file_lock
);
924 __put_unused_fd(files
, fd
);
925 spin_unlock(&files
->file_lock
);
928 EXPORT_SYMBOL(put_unused_fd
);
931 * Install a file pointer in the fd array.
933 * The VFS is full of places where we drop the files lock between
934 * setting the open_fds bitmap and installing the file in the file
935 * array. At any such point, we are vulnerable to a dup2() race
936 * installing a file in the array before us. We need to detect this and
937 * fput() the struct file we are about to overwrite in this case.
939 * It should never happen - if we allow dup2() do it, _really_ bad things
943 void fastcall
fd_install(unsigned int fd
, struct file
* file
)
945 struct files_struct
*files
= current
->files
;
947 spin_lock(&files
->file_lock
);
948 fdt
= files_fdtable(files
);
949 BUG_ON(fdt
->fd
[fd
] != NULL
);
950 rcu_assign_pointer(fdt
->fd
[fd
], file
);
951 spin_unlock(&files
->file_lock
);
954 EXPORT_SYMBOL(fd_install
);
956 long do_sys_open(int dfd
, const char __user
*filename
, int flags
, int mode
)
958 char *tmp
= getname(filename
);
959 int fd
= PTR_ERR(tmp
);
962 fd
= get_unused_fd();
964 struct file
*f
= do_filp_open(dfd
, tmp
, flags
, mode
);
969 fsnotify_open(f
->f_path
.dentry
);
978 asmlinkage
long sys_open(const char __user
*filename
, int flags
, int mode
)
982 if (force_o_largefile())
983 flags
|= O_LARGEFILE
;
985 ret
= do_sys_open(AT_FDCWD
, filename
, flags
, mode
);
986 /* avoid REGPARM breakage on x86: */
987 prevent_tail_call(ret
);
990 EXPORT_SYMBOL_GPL(sys_open
);
992 asmlinkage
long sys_openat(int dfd
, const char __user
*filename
, int flags
,
997 if (force_o_largefile())
998 flags
|= O_LARGEFILE
;
1000 ret
= do_sys_open(dfd
, filename
, flags
, mode
);
1001 /* avoid REGPARM breakage on x86: */
1002 prevent_tail_call(ret
);
1009 * For backward compatibility? Maybe this should be moved
1010 * into arch/i386 instead?
1012 asmlinkage
long sys_creat(const char __user
* pathname
, int mode
)
1014 return sys_open(pathname
, O_CREAT
| O_WRONLY
| O_TRUNC
, mode
);
1020 * "id" is the POSIX thread ID. We use the
1021 * files pointer for this..
1023 int filp_close(struct file
*filp
, fl_owner_t id
)
1027 if (!file_count(filp
)) {
1028 printk(KERN_ERR
"VFS: Close: file count is 0\n");
1032 if (filp
->f_op
&& filp
->f_op
->flush
)
1033 retval
= filp
->f_op
->flush(filp
, id
);
1035 dnotify_flush(filp
, id
);
1036 locks_remove_posix(filp
, id
);
1041 EXPORT_SYMBOL(filp_close
);
1044 * Careful here! We test whether the file pointer is NULL before
1045 * releasing the fd. This ensures that one clone task can't release
1046 * an fd while another clone is opening it.
1048 asmlinkage
long sys_close(unsigned int fd
)
1051 struct files_struct
*files
= current
->files
;
1052 struct fdtable
*fdt
;
1055 spin_lock(&files
->file_lock
);
1056 fdt
= files_fdtable(files
);
1057 if (fd
>= fdt
->max_fds
)
1062 rcu_assign_pointer(fdt
->fd
[fd
], NULL
);
1063 FD_CLR(fd
, fdt
->close_on_exec
);
1064 __put_unused_fd(files
, fd
);
1065 spin_unlock(&files
->file_lock
);
1066 retval
= filp_close(filp
, files
);
1068 /* can't restart close syscall because file table entry was cleared */
1069 if (unlikely(retval
== -ERESTARTSYS
||
1070 retval
== -ERESTARTNOINTR
||
1071 retval
== -ERESTARTNOHAND
||
1072 retval
== -ERESTART_RESTARTBLOCK
))
1078 spin_unlock(&files
->file_lock
);
1082 EXPORT_SYMBOL(sys_close
);
1085 * This routine simulates a hangup on the tty, to arrange that users
1086 * are given clean terminals at login time.
1088 asmlinkage
long sys_vhangup(void)
1090 if (capable(CAP_SYS_TTY_CONFIG
)) {
1091 /* XXX: this needs locking */
1092 tty_vhangup(current
->signal
->tty
);
1099 * Called when an inode is about to be open.
1100 * We use this to disallow opening large files on 32bit systems if
1101 * the caller didn't specify O_LARGEFILE. On 64bit systems we force
1102 * on this flag in sys_open.
1104 int generic_file_open(struct inode
* inode
, struct file
* filp
)
1106 if (!(filp
->f_flags
& O_LARGEFILE
) && i_size_read(inode
) > MAX_NON_LFS
)
1111 EXPORT_SYMBOL(generic_file_open
);
1114 * This is used by subsystems that don't want seekable
1117 int nonseekable_open(struct inode
*inode
, struct file
*filp
)
1119 filp
->f_mode
&= ~(FMODE_LSEEK
| FMODE_PREAD
| FMODE_PWRITE
);
1123 EXPORT_SYMBOL(nonseekable_open
);
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