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b47aab39c0572242c607495c37c15928fbf8290c
4 * Copyright (C) 1991, 1992 Linus Torvalds
7 #include <linux/string.h>
9 #include <linux/file.h>
10 #include <linux/fdtable.h>
11 #include <linux/fsnotify.h>
12 #include <linux/module.h>
13 #include <linux/tty.h>
14 #include <linux/namei.h>
15 #include <linux/backing-dev.h>
16 #include <linux/capability.h>
17 #include <linux/securebits.h>
18 #include <linux/security.h>
19 #include <linux/mount.h>
20 #include <linux/fcntl.h>
21 #include <linux/slab.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>
30 #include <linux/fs_struct.h>
31 #include <linux/ima.h>
32 #include <linux/dnotify.h>
36 int do_truncate(struct dentry
*dentry
, loff_t length
, unsigned int time_attrs
,
40 struct iattr newattrs
;
42 /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */
46 newattrs
.ia_size
= length
;
47 newattrs
.ia_valid
= ATTR_SIZE
| time_attrs
;
49 newattrs
.ia_file
= filp
;
50 newattrs
.ia_valid
|= ATTR_FILE
;
53 /* Remove suid/sgid on truncate too */
54 ret
= should_remove_suid(dentry
);
56 newattrs
.ia_valid
|= ret
| ATTR_FORCE
;
58 mutex_lock(&dentry
->d_inode
->i_mutex
);
59 ret
= notify_change(dentry
, &newattrs
);
60 mutex_unlock(&dentry
->d_inode
->i_mutex
);
64 static long do_sys_truncate(const char __user
*pathname
, loff_t length
)
71 if (length
< 0) /* sorry, but loff_t says... */
74 error
= user_path(pathname
, &path
);
77 inode
= path
.dentry
->d_inode
;
79 /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
81 if (S_ISDIR(inode
->i_mode
))
85 if (!S_ISREG(inode
->i_mode
))
88 error
= mnt_want_write(path
.mnt
);
92 error
= inode_permission(inode
, MAY_WRITE
);
94 goto mnt_drop_write_and_out
;
98 goto mnt_drop_write_and_out
;
100 error
= get_write_access(inode
);
102 goto mnt_drop_write_and_out
;
105 * Make sure that there are no leases. get_write_access() protects
106 * against the truncate racing with a lease-granting setlease().
108 error
= break_lease(inode
, O_WRONLY
);
110 goto put_write_and_out
;
112 error
= locks_verify_truncate(inode
, NULL
, length
);
114 error
= security_path_truncate(&path
);
116 error
= do_truncate(path
.dentry
, length
, 0, NULL
);
119 put_write_access(inode
);
120 mnt_drop_write_and_out
:
121 mnt_drop_write(path
.mnt
);
128 SYSCALL_DEFINE2(truncate
, const char __user
*, path
, long, length
)
130 return do_sys_truncate(path
, length
);
133 static long do_sys_ftruncate(unsigned int fd
, loff_t length
, int small
)
135 struct inode
* inode
;
136 struct dentry
*dentry
;
148 /* explicitly opened as large or we are on 64-bit box */
149 if (file
->f_flags
& O_LARGEFILE
)
152 dentry
= file
->f_path
.dentry
;
153 inode
= dentry
->d_inode
;
155 if (!S_ISREG(inode
->i_mode
) || !(file
->f_mode
& FMODE_WRITE
))
159 /* Cannot ftruncate over 2^31 bytes without large file support */
160 if (small
&& length
> MAX_NON_LFS
)
164 if (IS_APPEND(inode
))
167 error
= locks_verify_truncate(inode
, file
, length
);
169 error
= security_path_truncate(&file
->f_path
);
171 error
= do_truncate(dentry
, length
, ATTR_MTIME
|ATTR_CTIME
, file
);
178 SYSCALL_DEFINE2(ftruncate
, unsigned int, fd
, unsigned long, length
)
180 long ret
= do_sys_ftruncate(fd
, length
, 1);
181 /* avoid REGPARM breakage on x86: */
182 asmlinkage_protect(2, ret
, fd
, length
);
186 /* LFS versions of truncate are only needed on 32 bit machines */
187 #if BITS_PER_LONG == 32
188 SYSCALL_DEFINE(truncate64
)(const char __user
* path
, loff_t length
)
190 return do_sys_truncate(path
, length
);
192 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
193 asmlinkage
long SyS_truncate64(long path
, loff_t length
)
195 return SYSC_truncate64((const char __user
*) path
, length
);
197 SYSCALL_ALIAS(sys_truncate64
, SyS_truncate64
);
200 SYSCALL_DEFINE(ftruncate64
)(unsigned int fd
, loff_t length
)
202 long ret
= do_sys_ftruncate(fd
, length
, 0);
203 /* avoid REGPARM breakage on x86: */
204 asmlinkage_protect(2, ret
, fd
, length
);
207 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
208 asmlinkage
long SyS_ftruncate64(long fd
, loff_t length
)
210 return SYSC_ftruncate64((unsigned int) fd
, length
);
212 SYSCALL_ALIAS(sys_ftruncate64
, SyS_ftruncate64
);
214 #endif /* BITS_PER_LONG == 32 */
217 int do_fallocate(struct file
*file
, int mode
, loff_t offset
, loff_t len
)
219 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
222 if (offset
< 0 || len
<= 0)
225 /* Return error if mode is not supported */
226 if (mode
& ~(FALLOC_FL_KEEP_SIZE
| FALLOC_FL_PUNCH_HOLE
))
229 /* Punch hole must have keep size set */
230 if ((mode
& FALLOC_FL_PUNCH_HOLE
) &&
231 !(mode
& FALLOC_FL_KEEP_SIZE
))
234 if (!(file
->f_mode
& FMODE_WRITE
))
237 /* It's not possible punch hole on append only file */
238 if (mode
& FALLOC_FL_PUNCH_HOLE
&& IS_APPEND(inode
))
241 if (IS_IMMUTABLE(inode
))
245 * Revalidate the write permissions, in case security policy has
246 * changed since the files were opened.
248 ret
= security_file_permission(file
, MAY_WRITE
);
252 if (S_ISFIFO(inode
->i_mode
))
256 * Let individual file system decide if it supports preallocation
257 * for directories or not.
259 if (!S_ISREG(inode
->i_mode
) && !S_ISDIR(inode
->i_mode
))
262 /* Check for wrap through zero too */
263 if (((offset
+ len
) > inode
->i_sb
->s_maxbytes
) || ((offset
+ len
) < 0))
266 if (!file
->f_op
->fallocate
)
269 return file
->f_op
->fallocate(file
, mode
, offset
, len
);
272 SYSCALL_DEFINE(fallocate
)(int fd
, int mode
, loff_t offset
, loff_t len
)
279 error
= do_fallocate(file
, mode
, offset
, len
);
286 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
287 asmlinkage
long SyS_fallocate(long fd
, long mode
, loff_t offset
, loff_t len
)
289 return SYSC_fallocate((int)fd
, (int)mode
, offset
, len
);
291 SYSCALL_ALIAS(sys_fallocate
, SyS_fallocate
);
295 * access() needs to use the real uid/gid, not the effective uid/gid.
296 * We do this by temporarily clearing all FS-related capabilities and
297 * switching the fsuid/fsgid around to the real ones.
299 SYSCALL_DEFINE3(faccessat
, int, dfd
, const char __user
*, filename
, int, mode
)
301 const struct cred
*old_cred
;
302 struct cred
*override_cred
;
307 if (mode
& ~S_IRWXO
) /* where's F_OK, X_OK, W_OK, R_OK? */
310 override_cred
= prepare_creds();
314 override_cred
->fsuid
= override_cred
->uid
;
315 override_cred
->fsgid
= override_cred
->gid
;
317 if (!issecure(SECURE_NO_SETUID_FIXUP
)) {
318 /* Clear the capabilities if we switch to a non-root user */
319 if (override_cred
->uid
)
320 cap_clear(override_cred
->cap_effective
);
322 override_cred
->cap_effective
=
323 override_cred
->cap_permitted
;
326 old_cred
= override_creds(override_cred
);
328 res
= user_path_at(dfd
, filename
, LOOKUP_FOLLOW
, &path
);
332 inode
= path
.dentry
->d_inode
;
334 if ((mode
& MAY_EXEC
) && S_ISREG(inode
->i_mode
)) {
336 * MAY_EXEC on regular files is denied if the fs is mounted
337 * with the "noexec" flag.
340 if (path
.mnt
->mnt_flags
& MNT_NOEXEC
)
341 goto out_path_release
;
344 res
= inode_permission(inode
, mode
| MAY_ACCESS
);
345 /* SuS v2 requires we report a read only fs too */
346 if (res
|| !(mode
& S_IWOTH
) || special_file(inode
->i_mode
))
347 goto out_path_release
;
349 * This is a rare case where using __mnt_is_readonly()
350 * is OK without a mnt_want/drop_write() pair. Since
351 * no actual write to the fs is performed here, we do
352 * not need to telegraph to that to anyone.
354 * By doing this, we accept that this access is
355 * inherently racy and know that the fs may change
356 * state before we even see this result.
358 if (__mnt_is_readonly(path
.mnt
))
364 revert_creds(old_cred
);
365 put_cred(override_cred
);
369 SYSCALL_DEFINE2(access
, const char __user
*, filename
, int, mode
)
371 return sys_faccessat(AT_FDCWD
, filename
, mode
);
374 SYSCALL_DEFINE1(chdir
, const char __user
*, filename
)
379 error
= user_path_dir(filename
, &path
);
383 error
= inode_permission(path
.dentry
->d_inode
, MAY_EXEC
| MAY_CHDIR
);
387 set_fs_pwd(current
->fs
, &path
);
395 SYSCALL_DEFINE1(fchdir
, unsigned int, fd
)
406 inode
= file
->f_path
.dentry
->d_inode
;
409 if (!S_ISDIR(inode
->i_mode
))
412 error
= inode_permission(inode
, MAY_EXEC
| MAY_CHDIR
);
414 set_fs_pwd(current
->fs
, &file
->f_path
);
421 SYSCALL_DEFINE1(chroot
, const char __user
*, filename
)
426 error
= user_path_dir(filename
, &path
);
430 error
= inode_permission(path
.dentry
->d_inode
, MAY_EXEC
| MAY_CHDIR
);
435 if (!capable(CAP_SYS_CHROOT
))
437 error
= security_path_chroot(&path
);
441 set_fs_root(current
->fs
, &path
);
449 SYSCALL_DEFINE2(fchmod
, unsigned int, fd
, mode_t
, mode
)
451 struct inode
* inode
;
452 struct dentry
* dentry
;
455 struct iattr newattrs
;
461 dentry
= file
->f_path
.dentry
;
462 inode
= dentry
->d_inode
;
464 audit_inode(NULL
, dentry
);
466 err
= mnt_want_write_file(file
);
469 mutex_lock(&inode
->i_mutex
);
470 err
= security_path_chmod(dentry
, file
->f_vfsmnt
, mode
);
473 if (mode
== (mode_t
) -1)
474 mode
= inode
->i_mode
;
475 newattrs
.ia_mode
= (mode
& S_IALLUGO
) | (inode
->i_mode
& ~S_IALLUGO
);
476 newattrs
.ia_valid
= ATTR_MODE
| ATTR_CTIME
;
477 err
= notify_change(dentry
, &newattrs
);
479 mutex_unlock(&inode
->i_mutex
);
480 mnt_drop_write(file
->f_path
.mnt
);
487 SYSCALL_DEFINE3(fchmodat
, int, dfd
, const char __user
*, filename
, mode_t
, mode
)
492 struct iattr newattrs
;
494 error
= user_path_at(dfd
, filename
, LOOKUP_FOLLOW
, &path
);
497 inode
= path
.dentry
->d_inode
;
499 error
= mnt_want_write(path
.mnt
);
502 mutex_lock(&inode
->i_mutex
);
503 error
= security_path_chmod(path
.dentry
, path
.mnt
, mode
);
506 if (mode
== (mode_t
) -1)
507 mode
= inode
->i_mode
;
508 newattrs
.ia_mode
= (mode
& S_IALLUGO
) | (inode
->i_mode
& ~S_IALLUGO
);
509 newattrs
.ia_valid
= ATTR_MODE
| ATTR_CTIME
;
510 error
= notify_change(path
.dentry
, &newattrs
);
512 mutex_unlock(&inode
->i_mutex
);
513 mnt_drop_write(path
.mnt
);
520 SYSCALL_DEFINE2(chmod
, const char __user
*, filename
, mode_t
, mode
)
522 return sys_fchmodat(AT_FDCWD
, filename
, mode
);
525 static int chown_common(struct path
*path
, uid_t user
, gid_t group
)
527 struct inode
*inode
= path
->dentry
->d_inode
;
529 struct iattr newattrs
;
531 newattrs
.ia_valid
= ATTR_CTIME
;
532 if (user
!= (uid_t
) -1) {
533 newattrs
.ia_valid
|= ATTR_UID
;
534 newattrs
.ia_uid
= user
;
536 if (group
!= (gid_t
) -1) {
537 newattrs
.ia_valid
|= ATTR_GID
;
538 newattrs
.ia_gid
= group
;
540 if (!S_ISDIR(inode
->i_mode
))
542 ATTR_KILL_SUID
| ATTR_KILL_SGID
| ATTR_KILL_PRIV
;
543 mutex_lock(&inode
->i_mutex
);
544 error
= security_path_chown(path
, user
, group
);
546 error
= notify_change(path
->dentry
, &newattrs
);
547 mutex_unlock(&inode
->i_mutex
);
552 SYSCALL_DEFINE3(chown
, const char __user
*, filename
, uid_t
, user
, gid_t
, group
)
557 error
= user_path(filename
, &path
);
560 error
= mnt_want_write(path
.mnt
);
563 error
= chown_common(&path
, user
, group
);
564 mnt_drop_write(path
.mnt
);
571 SYSCALL_DEFINE5(fchownat
, int, dfd
, const char __user
*, filename
, uid_t
, user
,
572 gid_t
, group
, int, flag
)
578 if ((flag
& ~AT_SYMLINK_NOFOLLOW
) != 0)
581 follow
= (flag
& AT_SYMLINK_NOFOLLOW
) ? 0 : LOOKUP_FOLLOW
;
582 error
= user_path_at(dfd
, filename
, follow
, &path
);
585 error
= mnt_want_write(path
.mnt
);
588 error
= chown_common(&path
, user
, group
);
589 mnt_drop_write(path
.mnt
);
596 SYSCALL_DEFINE3(lchown
, const char __user
*, filename
, uid_t
, user
, gid_t
, group
)
601 error
= user_lpath(filename
, &path
);
604 error
= mnt_want_write(path
.mnt
);
607 error
= chown_common(&path
, user
, group
);
608 mnt_drop_write(path
.mnt
);
615 SYSCALL_DEFINE3(fchown
, unsigned int, fd
, uid_t
, user
, gid_t
, group
)
619 struct dentry
* dentry
;
625 error
= mnt_want_write_file(file
);
628 dentry
= file
->f_path
.dentry
;
629 audit_inode(NULL
, dentry
);
630 error
= chown_common(&file
->f_path
, user
, group
);
631 mnt_drop_write(file
->f_path
.mnt
);
639 * You have to be very careful that these write
640 * counts get cleaned up in error cases and
641 * upon __fput(). This should probably never
642 * be called outside of __dentry_open().
644 static inline int __get_file_write_access(struct inode
*inode
,
645 struct vfsmount
*mnt
)
648 error
= get_write_access(inode
);
652 * Do not take mount writer counts on
653 * special files since no writes to
654 * the mount itself will occur.
656 if (!special_file(inode
->i_mode
)) {
658 * Balanced in __fput()
660 error
= mnt_want_write(mnt
);
662 put_write_access(inode
);
667 static struct file
*__dentry_open(struct dentry
*dentry
, struct vfsmount
*mnt
,
669 int (*open
)(struct inode
*, struct file
*),
670 const struct cred
*cred
)
675 f
->f_mode
= OPEN_FMODE(f
->f_flags
) | FMODE_LSEEK
|
676 FMODE_PREAD
| FMODE_PWRITE
;
677 inode
= dentry
->d_inode
;
678 if (f
->f_mode
& FMODE_WRITE
) {
679 error
= __get_file_write_access(inode
, mnt
);
682 if (!special_file(inode
->i_mode
))
686 f
->f_mapping
= inode
->i_mapping
;
687 f
->f_path
.dentry
= dentry
;
690 f
->f_op
= fops_get(inode
->i_fop
);
691 file_sb_list_add(f
, inode
->i_sb
);
693 error
= security_dentry_open(f
, cred
);
697 if (!open
&& f
->f_op
)
698 open
= f
->f_op
->open
;
700 error
= open(inode
, f
);
706 f
->f_flags
&= ~(O_CREAT
| O_EXCL
| O_NOCTTY
| O_TRUNC
);
708 file_ra_state_init(&f
->f_ra
, f
->f_mapping
->host
->i_mapping
);
710 /* NB: we're sure to have correct a_ops only after f_op->open */
711 if (f
->f_flags
& O_DIRECT
) {
712 if (!f
->f_mapping
->a_ops
||
713 ((!f
->f_mapping
->a_ops
->direct_IO
) &&
714 (!f
->f_mapping
->a_ops
->get_xip_mem
))) {
716 f
= ERR_PTR(-EINVAL
);
724 if (f
->f_mode
& FMODE_WRITE
) {
725 put_write_access(inode
);
726 if (!special_file(inode
->i_mode
)) {
728 * We don't consider this a real
729 * mnt_want/drop_write() pair
730 * because it all happenend right
731 * here, so just reset the state.
738 f
->f_path
.dentry
= NULL
;
739 f
->f_path
.mnt
= NULL
;
744 return ERR_PTR(error
);
748 * lookup_instantiate_filp - instantiates the open intent filp
749 * @nd: pointer to nameidata
750 * @dentry: pointer to dentry
751 * @open: open callback
753 * Helper for filesystems that want to use lookup open intents and pass back
754 * a fully instantiated struct file to the caller.
755 * This function is meant to be called from within a filesystem's
757 * Beware of calling it for non-regular files! Those ->open methods might block
758 * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo,
759 * leading to a deadlock, as nobody can open that fifo anymore, because
760 * another process to open fifo will block on locked parent when doing lookup).
761 * Note that in case of error, nd->intent.open.file is destroyed, but the
762 * path information remains valid.
763 * If the open callback is set to NULL, then the standard f_op->open()
764 * filesystem callback is substituted.
766 struct file
*lookup_instantiate_filp(struct nameidata
*nd
, struct dentry
*dentry
,
767 int (*open
)(struct inode
*, struct file
*))
769 const struct cred
*cred
= current_cred();
771 if (IS_ERR(nd
->intent
.open
.file
))
775 nd
->intent
.open
.file
= __dentry_open(dget(dentry
), mntget(nd
->path
.mnt
),
776 nd
->intent
.open
.file
,
779 return nd
->intent
.open
.file
;
781 release_open_intent(nd
);
782 nd
->intent
.open
.file
= (struct file
*)dentry
;
785 EXPORT_SYMBOL_GPL(lookup_instantiate_filp
);
788 * nameidata_to_filp - convert a nameidata to an open filp.
789 * @nd: pointer to nameidata
792 * Note that this function destroys the original nameidata
794 struct file
*nameidata_to_filp(struct nameidata
*nd
)
796 const struct cred
*cred
= current_cred();
799 /* Pick up the filp from the open intent */
800 filp
= nd
->intent
.open
.file
;
801 nd
->intent
.open
.file
= NULL
;
803 /* Has the filesystem initialised the file for us? */
804 if (filp
->f_path
.dentry
== NULL
) {
806 filp
= __dentry_open(nd
->path
.dentry
, nd
->path
.mnt
, filp
,
813 * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
816 struct file
*dentry_open(struct dentry
*dentry
, struct vfsmount
*mnt
, int flags
,
817 const struct cred
*cred
)
822 validate_creds(cred
);
825 * We must always pass in a valid mount pointer. Historically
826 * callers got away with not passing it, but we must enforce this at
827 * the earliest possible point now to avoid strange problems deep in the
831 printk(KERN_WARNING
"%s called with NULL vfsmount\n", __func__
);
833 return ERR_PTR(-EINVAL
);
837 f
= get_empty_filp();
841 return ERR_PTR(error
);
845 return __dentry_open(dentry
, mnt
, f
, NULL
, cred
);
847 EXPORT_SYMBOL(dentry_open
);
849 static void __put_unused_fd(struct files_struct
*files
, unsigned int fd
)
851 struct fdtable
*fdt
= files_fdtable(files
);
852 __FD_CLR(fd
, fdt
->open_fds
);
853 if (fd
< files
->next_fd
)
857 void put_unused_fd(unsigned int fd
)
859 struct files_struct
*files
= current
->files
;
860 spin_lock(&files
->file_lock
);
861 __put_unused_fd(files
, fd
);
862 spin_unlock(&files
->file_lock
);
865 EXPORT_SYMBOL(put_unused_fd
);
868 * Install a file pointer in the fd array.
870 * The VFS is full of places where we drop the files lock between
871 * setting the open_fds bitmap and installing the file in the file
872 * array. At any such point, we are vulnerable to a dup2() race
873 * installing a file in the array before us. We need to detect this and
874 * fput() the struct file we are about to overwrite in this case.
876 * It should never happen - if we allow dup2() do it, _really_ bad things
880 void fd_install(unsigned int fd
, struct file
*file
)
882 struct files_struct
*files
= current
->files
;
884 spin_lock(&files
->file_lock
);
885 fdt
= files_fdtable(files
);
886 BUG_ON(fdt
->fd
[fd
] != NULL
);
887 rcu_assign_pointer(fdt
->fd
[fd
], file
);
888 spin_unlock(&files
->file_lock
);
891 EXPORT_SYMBOL(fd_install
);
893 long do_sys_open(int dfd
, const char __user
*filename
, int flags
, int mode
)
895 char *tmp
= getname(filename
);
896 int fd
= PTR_ERR(tmp
);
899 fd
= get_unused_fd_flags(flags
);
901 struct file
*f
= do_filp_open(dfd
, tmp
, flags
, mode
, 0);
915 SYSCALL_DEFINE3(open
, const char __user
*, filename
, int, flags
, int, mode
)
919 if (force_o_largefile())
920 flags
|= O_LARGEFILE
;
922 ret
= do_sys_open(AT_FDCWD
, filename
, flags
, mode
);
923 /* avoid REGPARM breakage on x86: */
924 asmlinkage_protect(3, ret
, filename
, flags
, mode
);
928 SYSCALL_DEFINE4(openat
, int, dfd
, const char __user
*, filename
, int, flags
,
933 if (force_o_largefile())
934 flags
|= O_LARGEFILE
;
936 ret
= do_sys_open(dfd
, filename
, flags
, mode
);
937 /* avoid REGPARM breakage on x86: */
938 asmlinkage_protect(4, ret
, dfd
, filename
, flags
, mode
);
945 * For backward compatibility? Maybe this should be moved
946 * into arch/i386 instead?
948 SYSCALL_DEFINE2(creat
, const char __user
*, pathname
, int, mode
)
950 return sys_open(pathname
, O_CREAT
| O_WRONLY
| O_TRUNC
, mode
);
956 * "id" is the POSIX thread ID. We use the
957 * files pointer for this..
959 int filp_close(struct file
*filp
, fl_owner_t id
)
963 if (!file_count(filp
)) {
964 printk(KERN_ERR
"VFS: Close: file count is 0\n");
968 if (filp
->f_op
&& filp
->f_op
->flush
)
969 retval
= filp
->f_op
->flush(filp
, id
);
971 dnotify_flush(filp
, id
);
972 locks_remove_posix(filp
, id
);
977 EXPORT_SYMBOL(filp_close
);
980 * Careful here! We test whether the file pointer is NULL before
981 * releasing the fd. This ensures that one clone task can't release
982 * an fd while another clone is opening it.
984 SYSCALL_DEFINE1(close
, unsigned int, fd
)
987 struct files_struct
*files
= current
->files
;
991 spin_lock(&files
->file_lock
);
992 fdt
= files_fdtable(files
);
993 if (fd
>= fdt
->max_fds
)
998 rcu_assign_pointer(fdt
->fd
[fd
], NULL
);
999 FD_CLR(fd
, fdt
->close_on_exec
);
1000 __put_unused_fd(files
, fd
);
1001 spin_unlock(&files
->file_lock
);
1002 retval
= filp_close(filp
, files
);
1004 /* can't restart close syscall because file table entry was cleared */
1005 if (unlikely(retval
== -ERESTARTSYS
||
1006 retval
== -ERESTARTNOINTR
||
1007 retval
== -ERESTARTNOHAND
||
1008 retval
== -ERESTART_RESTARTBLOCK
))
1014 spin_unlock(&files
->file_lock
);
1017 EXPORT_SYMBOL(sys_close
);
1020 * This routine simulates a hangup on the tty, to arrange that users
1021 * are given clean terminals at login time.
1023 SYSCALL_DEFINE0(vhangup
)
1025 if (capable(CAP_SYS_TTY_CONFIG
)) {
1033 * Called when an inode is about to be open.
1034 * We use this to disallow opening large files on 32bit systems if
1035 * the caller didn't specify O_LARGEFILE. On 64bit systems we force
1036 * on this flag in sys_open.
1038 int generic_file_open(struct inode
* inode
, struct file
* filp
)
1040 if (!(filp
->f_flags
& O_LARGEFILE
) && i_size_read(inode
) > MAX_NON_LFS
)
1045 EXPORT_SYMBOL(generic_file_open
);
1048 * This is used by subsystems that don't want seekable
1049 * file descriptors. The function is not supposed to ever fail, the only
1050 * reason it returns an 'int' and not 'void' is so that it can be plugged
1051 * directly into file_operations structure.
1053 int nonseekable_open(struct inode
*inode
, struct file
*filp
)
1055 filp
->f_mode
&= ~(FMODE_LSEEK
| FMODE_PREAD
| FMODE_PWRITE
);
1059 EXPORT_SYMBOL(nonseekable_open
);