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 asmlinkage long sys_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_special(long nsec)
45 return nsec == UTIME_OMIT || nsec == UTIME_NOW;
48 static bool nsec_valid(long nsec)
50 if (nsec_special(nsec))
53 return nsec >= 0 && nsec <= 999999999;
56 /* If times==NULL, set access and modification to current time,
57 * must be owner or have write permission.
58 * Else, update from *times, must be owner or super user.
60 long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags)
64 struct dentry *dentry;
66 struct iattr newattrs;
67 struct file *f = NULL;
71 if (times && (!nsec_valid(times[0].tv_nsec) ||
72 !nsec_valid(times[1].tv_nsec))) {
76 if (flags & ~AT_SYMLINK_NOFOLLOW)
79 if (filename == NULL && dfd != AT_FDCWD) {
81 if (flags & AT_SYMLINK_NOFOLLOW)
88 dentry = f->f_path.dentry;
91 error = __user_walk_fd(dfd, filename, (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW, &nd);
95 dentry = nd.path.dentry;
99 inode = dentry->d_inode;
101 error = mnt_want_write(mnt);
105 if (times && times[0].tv_nsec == UTIME_NOW &&
106 times[1].tv_nsec == UTIME_NOW)
109 /* Don't worry, the checks are done in inode_change_ok() */
110 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
113 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
114 goto mnt_drop_write_and_out;
116 if (times[0].tv_nsec == UTIME_OMIT)
117 newattrs.ia_valid &= ~ATTR_ATIME;
118 else if (times[0].tv_nsec != UTIME_NOW) {
119 newattrs.ia_atime.tv_sec = times[0].tv_sec;
120 newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
121 newattrs.ia_valid |= ATTR_ATIME_SET;
124 if (times[1].tv_nsec == UTIME_OMIT)
125 newattrs.ia_valid &= ~ATTR_MTIME;
126 else if (times[1].tv_nsec != UTIME_NOW) {
127 newattrs.ia_mtime.tv_sec = times[1].tv_sec;
128 newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
129 newattrs.ia_valid |= ATTR_MTIME_SET;
134 * If times is NULL or both times are either UTIME_OMIT or
135 * UTIME_NOW, then need to check permissions, because
136 * inode_change_ok() won't do it.
138 if (!times || (nsec_special(times[0].tv_nsec) &&
139 nsec_special(times[1].tv_nsec))) {
141 if (IS_IMMUTABLE(inode))
142 goto mnt_drop_write_and_out;
144 if (!is_owner_or_cap(inode)) {
146 if (!(f->f_mode & FMODE_WRITE))
147 goto mnt_drop_write_and_out;
149 error = vfs_permission(&nd, MAY_WRITE);
151 goto mnt_drop_write_and_out;
155 mutex_lock(&inode->i_mutex);
156 error = notify_change(dentry, &newattrs);
157 mutex_unlock(&inode->i_mutex);
158 mnt_drop_write_and_out:
169 asmlinkage long sys_utimensat(int dfd, char __user *filename, struct timespec __user *utimes, int flags)
171 struct timespec tstimes[2];
174 if (copy_from_user(&tstimes, utimes, sizeof(tstimes)))
176 if ((tstimes[0].tv_nsec == UTIME_OMIT ||
177 tstimes[0].tv_nsec == UTIME_NOW) &&
178 tstimes[0].tv_sec != 0)
180 if ((tstimes[1].tv_nsec == UTIME_OMIT ||
181 tstimes[1].tv_nsec == UTIME_NOW) &&
182 tstimes[1].tv_sec != 0)
185 /* Nothing to do, we must not even check the path. */
186 if (tstimes[0].tv_nsec == UTIME_OMIT &&
187 tstimes[1].tv_nsec == UTIME_OMIT)
191 return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
194 asmlinkage long sys_futimesat(int dfd, char __user *filename, struct timeval __user *utimes)
196 struct timeval times[2];
197 struct timespec tstimes[2];
200 if (copy_from_user(×, utimes, sizeof(times)))
203 /* This test is needed to catch all invalid values. If we
204 would test only in do_utimes we would miss those invalid
205 values truncated by the multiplication with 1000. Note
206 that we also catch UTIME_{NOW,OMIT} here which are only
207 valid for utimensat. */
208 if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
209 times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
212 tstimes[0].tv_sec = times[0].tv_sec;
213 tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
214 tstimes[1].tv_sec = times[1].tv_sec;
215 tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
218 return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
221 asmlinkage long sys_utimes(char __user *filename, struct timeval __user *utimes)
223 return sys_futimesat(AT_FDCWD, filename, utimes);