]>
git.ipfire.org Git - people/ms/linux.git/blob - fs/open.c
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
);
571 if (IS_RDONLY(inode
))
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
);
590 asmlinkage
long sys_fchmodat(int dfd
, const char __user
*filename
,
594 struct inode
* inode
;
596 struct iattr newattrs
;
598 error
= __user_walk_fd(dfd
, filename
, LOOKUP_FOLLOW
, &nd
);
601 inode
= nd
.path
.dentry
->d_inode
;
604 if (IS_RDONLY(inode
))
608 if (IS_IMMUTABLE(inode
) || IS_APPEND(inode
))
611 mutex_lock(&inode
->i_mutex
);
612 if (mode
== (mode_t
) -1)
613 mode
= inode
->i_mode
;
614 newattrs
.ia_mode
= (mode
& S_IALLUGO
) | (inode
->i_mode
& ~S_IALLUGO
);
615 newattrs
.ia_valid
= ATTR_MODE
| ATTR_CTIME
;
616 error
= notify_change(nd
.path
.dentry
, &newattrs
);
617 mutex_unlock(&inode
->i_mutex
);
625 asmlinkage
long sys_chmod(const char __user
*filename
, mode_t mode
)
627 return sys_fchmodat(AT_FDCWD
, filename
, mode
);
630 static int chown_common(struct dentry
* dentry
, uid_t user
, gid_t group
)
632 struct inode
* inode
;
634 struct iattr newattrs
;
637 if (!(inode
= dentry
->d_inode
)) {
638 printk(KERN_ERR
"chown_common: NULL inode\n");
642 if (IS_RDONLY(inode
))
645 if (IS_IMMUTABLE(inode
) || IS_APPEND(inode
))
647 newattrs
.ia_valid
= ATTR_CTIME
;
648 if (user
!= (uid_t
) -1) {
649 newattrs
.ia_valid
|= ATTR_UID
;
650 newattrs
.ia_uid
= user
;
652 if (group
!= (gid_t
) -1) {
653 newattrs
.ia_valid
|= ATTR_GID
;
654 newattrs
.ia_gid
= group
;
656 if (!S_ISDIR(inode
->i_mode
))
658 ATTR_KILL_SUID
| ATTR_KILL_SGID
| ATTR_KILL_PRIV
;
659 mutex_lock(&inode
->i_mutex
);
660 error
= notify_change(dentry
, &newattrs
);
661 mutex_unlock(&inode
->i_mutex
);
666 asmlinkage
long sys_chown(const char __user
* filename
, uid_t user
, gid_t group
)
671 error
= user_path_walk(filename
, &nd
);
674 error
= chown_common(nd
.path
.dentry
, user
, group
);
680 asmlinkage
long sys_fchownat(int dfd
, const char __user
*filename
, uid_t user
,
681 gid_t group
, int flag
)
687 if ((flag
& ~AT_SYMLINK_NOFOLLOW
) != 0)
690 follow
= (flag
& AT_SYMLINK_NOFOLLOW
) ? 0 : LOOKUP_FOLLOW
;
691 error
= __user_walk_fd(dfd
, filename
, follow
, &nd
);
694 error
= chown_common(nd
.path
.dentry
, user
, group
);
700 asmlinkage
long sys_lchown(const char __user
* filename
, uid_t user
, gid_t group
)
705 error
= user_path_walk_link(filename
, &nd
);
708 error
= chown_common(nd
.path
.dentry
, user
, group
);
715 asmlinkage
long sys_fchown(unsigned int fd
, uid_t user
, gid_t group
)
719 struct dentry
* dentry
;
725 dentry
= file
->f_path
.dentry
;
726 audit_inode(NULL
, dentry
);
727 error
= chown_common(dentry
, user
, group
);
734 * You have to be very careful that these write
735 * counts get cleaned up in error cases and
736 * upon __fput(). This should probably never
737 * be called outside of __dentry_open().
739 static inline int __get_file_write_access(struct inode
*inode
,
740 struct vfsmount
*mnt
)
743 error
= get_write_access(inode
);
747 * Do not take mount writer counts on
748 * special files since no writes to
749 * the mount itself will occur.
751 if (!special_file(inode
->i_mode
)) {
753 * Balanced in __fput()
755 error
= mnt_want_write(mnt
);
757 put_write_access(inode
);
762 static struct file
*__dentry_open(struct dentry
*dentry
, struct vfsmount
*mnt
,
763 int flags
, struct file
*f
,
764 int (*open
)(struct inode
*, struct file
*))
770 f
->f_mode
= ((flags
+1) & O_ACCMODE
) | FMODE_LSEEK
|
771 FMODE_PREAD
| FMODE_PWRITE
;
772 inode
= dentry
->d_inode
;
773 if (f
->f_mode
& FMODE_WRITE
) {
774 error
= __get_file_write_access(inode
, mnt
);
779 f
->f_mapping
= inode
->i_mapping
;
780 f
->f_path
.dentry
= dentry
;
783 f
->f_op
= fops_get(inode
->i_fop
);
784 file_move(f
, &inode
->i_sb
->s_files
);
786 error
= security_dentry_open(f
);
790 if (!open
&& f
->f_op
)
791 open
= f
->f_op
->open
;
793 error
= open(inode
, f
);
798 f
->f_flags
&= ~(O_CREAT
| O_EXCL
| O_NOCTTY
| O_TRUNC
);
800 file_ra_state_init(&f
->f_ra
, f
->f_mapping
->host
->i_mapping
);
802 /* NB: we're sure to have correct a_ops only after f_op->open */
803 if (f
->f_flags
& O_DIRECT
) {
804 if (!f
->f_mapping
->a_ops
||
805 ((!f
->f_mapping
->a_ops
->direct_IO
) &&
806 (!f
->f_mapping
->a_ops
->get_xip_page
))) {
808 f
= ERR_PTR(-EINVAL
);
816 if (f
->f_mode
& FMODE_WRITE
) {
817 put_write_access(inode
);
818 if (!special_file(inode
->i_mode
))
822 f
->f_path
.dentry
= NULL
;
823 f
->f_path
.mnt
= NULL
;
828 return ERR_PTR(error
);
832 * lookup_instantiate_filp - instantiates the open intent filp
833 * @nd: pointer to nameidata
834 * @dentry: pointer to dentry
835 * @open: open callback
837 * Helper for filesystems that want to use lookup open intents and pass back
838 * a fully instantiated struct file to the caller.
839 * This function is meant to be called from within a filesystem's
841 * Beware of calling it for non-regular files! Those ->open methods might block
842 * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo,
843 * leading to a deadlock, as nobody can open that fifo anymore, because
844 * another process to open fifo will block on locked parent when doing lookup).
845 * Note that in case of error, nd->intent.open.file is destroyed, but the
846 * path information remains valid.
847 * If the open callback is set to NULL, then the standard f_op->open()
848 * filesystem callback is substituted.
850 struct file
*lookup_instantiate_filp(struct nameidata
*nd
, struct dentry
*dentry
,
851 int (*open
)(struct inode
*, struct file
*))
853 if (IS_ERR(nd
->intent
.open
.file
))
857 nd
->intent
.open
.file
= __dentry_open(dget(dentry
), mntget(nd
->path
.mnt
),
858 nd
->intent
.open
.flags
- 1,
859 nd
->intent
.open
.file
,
862 return nd
->intent
.open
.file
;
864 release_open_intent(nd
);
865 nd
->intent
.open
.file
= (struct file
*)dentry
;
868 EXPORT_SYMBOL_GPL(lookup_instantiate_filp
);
871 * nameidata_to_filp - convert a nameidata to an open filp.
872 * @nd: pointer to nameidata
875 * Note that this function destroys the original nameidata
877 struct file
*nameidata_to_filp(struct nameidata
*nd
, int flags
)
881 /* Pick up the filp from the open intent */
882 filp
= nd
->intent
.open
.file
;
883 /* Has the filesystem initialised the file for us? */
884 if (filp
->f_path
.dentry
== NULL
)
885 filp
= __dentry_open(nd
->path
.dentry
, nd
->path
.mnt
, flags
, filp
,
893 * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
896 struct file
*dentry_open(struct dentry
*dentry
, struct vfsmount
*mnt
, int flags
)
902 * We must always pass in a valid mount pointer. Historically
903 * callers got away with not passing it, but we must enforce this at
904 * the earliest possible point now to avoid strange problems deep in the
908 printk(KERN_WARNING
"%s called with NULL vfsmount\n", __func__
);
910 return ERR_PTR(-EINVAL
);
914 f
= get_empty_filp();
918 return ERR_PTR(error
);
921 return __dentry_open(dentry
, mnt
, flags
, f
, NULL
);
923 EXPORT_SYMBOL(dentry_open
);
926 * Find an empty file descriptor entry, and mark it busy.
928 int get_unused_fd_flags(int flags
)
930 struct files_struct
* files
= current
->files
;
935 spin_lock(&files
->file_lock
);
938 fdt
= files_fdtable(files
);
939 fd
= find_next_zero_bit(fdt
->open_fds
->fds_bits
, fdt
->max_fds
,
943 * N.B. For clone tasks sharing a files structure, this test
944 * will limit the total number of files that can be opened.
946 if (fd
>= current
->signal
->rlim
[RLIMIT_NOFILE
].rlim_cur
)
949 /* Do we need to expand the fd array or fd set? */
950 error
= expand_files(files
, fd
);
956 * If we needed to expand the fs array we
957 * might have blocked - try again.
963 FD_SET(fd
, fdt
->open_fds
);
964 if (flags
& O_CLOEXEC
)
965 FD_SET(fd
, fdt
->close_on_exec
);
967 FD_CLR(fd
, fdt
->close_on_exec
);
968 files
->next_fd
= fd
+ 1;
971 if (fdt
->fd
[fd
] != NULL
) {
972 printk(KERN_WARNING
"get_unused_fd: slot %d not NULL!\n", fd
);
979 spin_unlock(&files
->file_lock
);
983 int get_unused_fd(void)
985 return get_unused_fd_flags(0);
988 EXPORT_SYMBOL(get_unused_fd
);
990 static void __put_unused_fd(struct files_struct
*files
, unsigned int fd
)
992 struct fdtable
*fdt
= files_fdtable(files
);
993 __FD_CLR(fd
, fdt
->open_fds
);
994 if (fd
< files
->next_fd
)
998 void put_unused_fd(unsigned int fd
)
1000 struct files_struct
*files
= current
->files
;
1001 spin_lock(&files
->file_lock
);
1002 __put_unused_fd(files
, fd
);
1003 spin_unlock(&files
->file_lock
);
1006 EXPORT_SYMBOL(put_unused_fd
);
1009 * Install a file pointer in the fd array.
1011 * The VFS is full of places where we drop the files lock between
1012 * setting the open_fds bitmap and installing the file in the file
1013 * array. At any such point, we are vulnerable to a dup2() race
1014 * installing a file in the array before us. We need to detect this and
1015 * fput() the struct file we are about to overwrite in this case.
1017 * It should never happen - if we allow dup2() do it, _really_ bad things
1021 void fd_install(unsigned int fd
, struct file
*file
)
1023 struct files_struct
*files
= current
->files
;
1024 struct fdtable
*fdt
;
1025 spin_lock(&files
->file_lock
);
1026 fdt
= files_fdtable(files
);
1027 BUG_ON(fdt
->fd
[fd
] != NULL
);
1028 rcu_assign_pointer(fdt
->fd
[fd
], file
);
1029 spin_unlock(&files
->file_lock
);
1032 EXPORT_SYMBOL(fd_install
);
1034 long do_sys_open(int dfd
, const char __user
*filename
, int flags
, int mode
)
1036 char *tmp
= getname(filename
);
1037 int fd
= PTR_ERR(tmp
);
1040 fd
= get_unused_fd_flags(flags
);
1042 struct file
*f
= do_filp_open(dfd
, tmp
, flags
, mode
);
1047 fsnotify_open(f
->f_path
.dentry
);
1056 asmlinkage
long sys_open(const char __user
*filename
, int flags
, int mode
)
1060 if (force_o_largefile())
1061 flags
|= O_LARGEFILE
;
1063 ret
= do_sys_open(AT_FDCWD
, filename
, flags
, mode
);
1064 /* avoid REGPARM breakage on x86: */
1065 asmlinkage_protect(3, ret
, filename
, flags
, mode
);
1069 asmlinkage
long sys_openat(int dfd
, const char __user
*filename
, int flags
,
1074 if (force_o_largefile())
1075 flags
|= O_LARGEFILE
;
1077 ret
= do_sys_open(dfd
, filename
, flags
, mode
);
1078 /* avoid REGPARM breakage on x86: */
1079 asmlinkage_protect(4, ret
, dfd
, filename
, flags
, mode
);
1086 * For backward compatibility? Maybe this should be moved
1087 * into arch/i386 instead?
1089 asmlinkage
long sys_creat(const char __user
* pathname
, int mode
)
1091 return sys_open(pathname
, O_CREAT
| O_WRONLY
| O_TRUNC
, mode
);
1097 * "id" is the POSIX thread ID. We use the
1098 * files pointer for this..
1100 int filp_close(struct file
*filp
, fl_owner_t id
)
1104 if (!file_count(filp
)) {
1105 printk(KERN_ERR
"VFS: Close: file count is 0\n");
1109 if (filp
->f_op
&& filp
->f_op
->flush
)
1110 retval
= filp
->f_op
->flush(filp
, id
);
1112 dnotify_flush(filp
, id
);
1113 locks_remove_posix(filp
, id
);
1118 EXPORT_SYMBOL(filp_close
);
1121 * Careful here! We test whether the file pointer is NULL before
1122 * releasing the fd. This ensures that one clone task can't release
1123 * an fd while another clone is opening it.
1125 asmlinkage
long sys_close(unsigned int fd
)
1128 struct files_struct
*files
= current
->files
;
1129 struct fdtable
*fdt
;
1132 spin_lock(&files
->file_lock
);
1133 fdt
= files_fdtable(files
);
1134 if (fd
>= fdt
->max_fds
)
1139 rcu_assign_pointer(fdt
->fd
[fd
], NULL
);
1140 FD_CLR(fd
, fdt
->close_on_exec
);
1141 __put_unused_fd(files
, fd
);
1142 spin_unlock(&files
->file_lock
);
1143 retval
= filp_close(filp
, files
);
1145 /* can't restart close syscall because file table entry was cleared */
1146 if (unlikely(retval
== -ERESTARTSYS
||
1147 retval
== -ERESTARTNOINTR
||
1148 retval
== -ERESTARTNOHAND
||
1149 retval
== -ERESTART_RESTARTBLOCK
))
1155 spin_unlock(&files
->file_lock
);
1159 EXPORT_SYMBOL(sys_close
);
1162 * This routine simulates a hangup on the tty, to arrange that users
1163 * are given clean terminals at login time.
1165 asmlinkage
long sys_vhangup(void)
1167 if (capable(CAP_SYS_TTY_CONFIG
)) {
1168 /* XXX: this needs locking */
1169 tty_vhangup(current
->signal
->tty
);
1176 * Called when an inode is about to be open.
1177 * We use this to disallow opening large files on 32bit systems if
1178 * the caller didn't specify O_LARGEFILE. On 64bit systems we force
1179 * on this flag in sys_open.
1181 int generic_file_open(struct inode
* inode
, struct file
* filp
)
1183 if (!(filp
->f_flags
& O_LARGEFILE
) && i_size_read(inode
) > MAX_NON_LFS
)
1188 EXPORT_SYMBOL(generic_file_open
);
1191 * This is used by subsystems that don't want seekable
1194 int nonseekable_open(struct inode
*inode
, struct file
*filp
)
1196 filp
->f_mode
&= ~(FMODE_LSEEK
| FMODE_PREAD
| FMODE_PWRITE
);
1200 EXPORT_SYMBOL(nonseekable_open
);