1 #include <linux/compiler.h>
2 #include <linux/file.h>
4 #include <linux/linkage.h>
5 #include <linux/mount.h>
6 #include <linux/namei.h>
7 #include <linux/sched.h>
8 #include <linux/stat.h>
9 #include <linux/utime.h>
10 #include <linux/syscalls.h>
11 #include <asm/uaccess.h>
12 #include <asm/unistd.h>
14 #ifdef __ARCH_WANT_SYS_UTIME
17 * sys_utime() can be implemented in user-level using sys_utimes().
18 * Is this for backwards compatibility? If so, why not move it
19 * into the appropriate arch directory (for those architectures that
23 /* If times==NULL, set access and modification to current time,
24 * must be owner or have write permission.
25 * Else, update from *times, must be owner or super user.
27 SYSCALL_DEFINE2(utime
, char __user
*, filename
, struct utimbuf __user
*, times
)
29 struct timespec tv
[2];
32 if (get_user(tv
[0].tv_sec
, ×
->actime
) ||
33 get_user(tv
[1].tv_sec
, ×
->modtime
))
38 return do_utimes(AT_FDCWD
, filename
, times
? tv
: NULL
, 0);
43 static bool nsec_valid(long nsec
)
45 if (nsec
== UTIME_OMIT
|| nsec
== UTIME_NOW
)
48 return nsec
>= 0 && nsec
<= 999999999;
51 static int utimes_common(struct path
*path
, struct timespec
*times
)
54 struct iattr newattrs
;
55 struct inode
*inode
= path
->dentry
->d_inode
;
57 error
= mnt_want_write(path
->mnt
);
61 if (times
&& times
[0].tv_nsec
== UTIME_NOW
&&
62 times
[1].tv_nsec
== UTIME_NOW
)
65 newattrs
.ia_valid
= ATTR_CTIME
| ATTR_MTIME
| ATTR_ATIME
;
67 if (times
[0].tv_nsec
== UTIME_OMIT
)
68 newattrs
.ia_valid
&= ~ATTR_ATIME
;
69 else if (times
[0].tv_nsec
!= UTIME_NOW
) {
70 newattrs
.ia_atime
.tv_sec
= times
[0].tv_sec
;
71 newattrs
.ia_atime
.tv_nsec
= times
[0].tv_nsec
;
72 newattrs
.ia_valid
|= ATTR_ATIME_SET
;
75 if (times
[1].tv_nsec
== UTIME_OMIT
)
76 newattrs
.ia_valid
&= ~ATTR_MTIME
;
77 else if (times
[1].tv_nsec
!= UTIME_NOW
) {
78 newattrs
.ia_mtime
.tv_sec
= times
[1].tv_sec
;
79 newattrs
.ia_mtime
.tv_nsec
= times
[1].tv_nsec
;
80 newattrs
.ia_valid
|= ATTR_MTIME_SET
;
83 * Tell inode_change_ok(), that this is an explicit time
84 * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
87 newattrs
.ia_valid
|= ATTR_TIMES_SET
;
90 * If times is NULL (or both times are UTIME_NOW),
91 * then we need to check permissions, because
92 * inode_change_ok() won't do it.
95 if (IS_IMMUTABLE(inode
))
96 goto mnt_drop_write_and_out
;
98 if (!is_owner_or_cap(inode
)) {
99 error
= inode_permission(inode
, MAY_WRITE
);
101 goto mnt_drop_write_and_out
;
104 mutex_lock(&inode
->i_mutex
);
105 error
= notify_change(path
->dentry
, &newattrs
);
106 mutex_unlock(&inode
->i_mutex
);
108 mnt_drop_write_and_out
:
109 mnt_drop_write(path
->mnt
);
115 * do_utimes - change times on filename or file descriptor
116 * @dfd: open file descriptor, -1 or AT_FDCWD
117 * @filename: path name or NULL
118 * @times: new times or NULL
119 * @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
121 * If filename is NULL and dfd refers to an open file, then operate on
122 * the file. Otherwise look up filename, possibly using dfd as a
125 * If times==NULL, set access and modification to current time,
126 * must be owner or have write permission.
127 * Else, update from *times, must be owner or super user.
129 long do_utimes(int dfd
, const char __user
*filename
, struct timespec
*times
,
134 if (times
&& (!nsec_valid(times
[0].tv_nsec
) ||
135 !nsec_valid(times
[1].tv_nsec
))) {
139 if (flags
& ~AT_SYMLINK_NOFOLLOW
)
142 if (filename
== NULL
&& dfd
!= AT_FDCWD
) {
145 if (flags
& AT_SYMLINK_NOFOLLOW
)
153 error
= utimes_common(&file
->f_path
, times
);
157 int lookup_flags
= 0;
159 if (!(flags
& AT_SYMLINK_NOFOLLOW
))
160 lookup_flags
|= LOOKUP_FOLLOW
;
162 error
= user_path_at(dfd
, filename
, lookup_flags
, &path
);
166 error
= utimes_common(&path
, times
);
174 SYSCALL_DEFINE4(utimensat
, int, dfd
, const char __user
*, filename
,
175 struct timespec __user
*, utimes
, int, flags
)
177 struct timespec tstimes
[2];
180 if (copy_from_user(&tstimes
, utimes
, sizeof(tstimes
)))
183 /* Nothing to do, we must not even check the path. */
184 if (tstimes
[0].tv_nsec
== UTIME_OMIT
&&
185 tstimes
[1].tv_nsec
== UTIME_OMIT
)
189 return do_utimes(dfd
, filename
, utimes
? tstimes
: NULL
, flags
);
192 SYSCALL_DEFINE3(futimesat
, int, dfd
, const char __user
*, filename
,
193 struct timeval __user
*, utimes
)
195 struct timeval times
[2];
196 struct timespec tstimes
[2];
199 if (copy_from_user(×
, utimes
, sizeof(times
)))
202 /* This test is needed to catch all invalid values. If we
203 would test only in do_utimes we would miss those invalid
204 values truncated by the multiplication with 1000. Note
205 that we also catch UTIME_{NOW,OMIT} here which are only
206 valid for utimensat. */
207 if (times
[0].tv_usec
>= 1000000 || times
[0].tv_usec
< 0 ||
208 times
[1].tv_usec
>= 1000000 || times
[1].tv_usec
< 0)
211 tstimes
[0].tv_sec
= times
[0].tv_sec
;
212 tstimes
[0].tv_nsec
= 1000 * times
[0].tv_usec
;
213 tstimes
[1].tv_sec
= times
[1].tv_sec
;
214 tstimes
[1].tv_nsec
= 1000 * times
[1].tv_usec
;
217 return do_utimes(dfd
, filename
, utimes
? tstimes
: NULL
, 0);
220 SYSCALL_DEFINE2(utimes
, char __user
*, filename
,
221 struct timeval __user
*, utimes
)
223 return sys_futimesat(AT_FDCWD
, filename
, utimes
);
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