staging: gasket: remove TODO item about SPDX usage
[linux-2.6/btrfs-unstable.git] / fs / utimes.c
blob69d4b6ba1bfb685489e27f06b21d94c95aa7f2a0
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/file.h>
3 #include <linux/mount.h>
4 #include <linux/namei.h>
5 #include <linux/utime.h>
6 #include <linux/syscalls.h>
7 #include <linux/uaccess.h>
8 #include <linux/compat.h>
9 #include <asm/unistd.h>
11 #ifdef __ARCH_WANT_SYS_UTIME
14 * sys_utime() can be implemented in user-level using sys_utimes().
15 * Is this for backwards compatibility? If so, why not move it
16 * into the appropriate arch directory (for those architectures that
17 * need it).
20 /* If times==NULL, set access and modification to current time,
21 * must be owner or have write permission.
22 * Else, update from *times, must be owner or super user.
24 SYSCALL_DEFINE2(utime, char __user *, filename, struct utimbuf __user *, times)
26 struct timespec64 tv[2];
28 if (times) {
29 if (get_user(tv[0].tv_sec, &times->actime) ||
30 get_user(tv[1].tv_sec, &times->modtime))
31 return -EFAULT;
32 tv[0].tv_nsec = 0;
33 tv[1].tv_nsec = 0;
35 return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
38 #endif
40 static bool nsec_valid(long nsec)
42 if (nsec == UTIME_OMIT || nsec == UTIME_NOW)
43 return true;
45 return nsec >= 0 && nsec <= 999999999;
48 static int utimes_common(const struct path *path, struct timespec64 *times)
50 int error;
51 struct iattr newattrs;
52 struct inode *inode = path->dentry->d_inode;
53 struct inode *delegated_inode = NULL;
55 error = mnt_want_write(path->mnt);
56 if (error)
57 goto out;
59 if (times && times[0].tv_nsec == UTIME_NOW &&
60 times[1].tv_nsec == UTIME_NOW)
61 times = NULL;
63 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
64 if (times) {
65 if (times[0].tv_nsec == UTIME_OMIT)
66 newattrs.ia_valid &= ~ATTR_ATIME;
67 else if (times[0].tv_nsec != UTIME_NOW) {
68 newattrs.ia_atime.tv_sec = times[0].tv_sec;
69 newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
70 newattrs.ia_valid |= ATTR_ATIME_SET;
73 if (times[1].tv_nsec == UTIME_OMIT)
74 newattrs.ia_valid &= ~ATTR_MTIME;
75 else if (times[1].tv_nsec != UTIME_NOW) {
76 newattrs.ia_mtime.tv_sec = times[1].tv_sec;
77 newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
78 newattrs.ia_valid |= ATTR_MTIME_SET;
81 * Tell setattr_prepare(), that this is an explicit time
82 * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
83 * were used.
85 newattrs.ia_valid |= ATTR_TIMES_SET;
86 } else {
87 newattrs.ia_valid |= ATTR_TOUCH;
89 retry_deleg:
90 inode_lock(inode);
91 error = notify_change(path->dentry, &newattrs, &delegated_inode);
92 inode_unlock(inode);
93 if (delegated_inode) {
94 error = break_deleg_wait(&delegated_inode);
95 if (!error)
96 goto retry_deleg;
99 mnt_drop_write(path->mnt);
100 out:
101 return error;
105 * do_utimes - change times on filename or file descriptor
106 * @dfd: open file descriptor, -1 or AT_FDCWD
107 * @filename: path name or NULL
108 * @times: new times or NULL
109 * @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
111 * If filename is NULL and dfd refers to an open file, then operate on
112 * the file. Otherwise look up filename, possibly using dfd as a
113 * starting point.
115 * If times==NULL, set access and modification to current time,
116 * must be owner or have write permission.
117 * Else, update from *times, must be owner or super user.
119 long do_utimes(int dfd, const char __user *filename, struct timespec64 *times,
120 int flags)
122 int error = -EINVAL;
124 if (times && (!nsec_valid(times[0].tv_nsec) ||
125 !nsec_valid(times[1].tv_nsec))) {
126 goto out;
129 if (flags & ~AT_SYMLINK_NOFOLLOW)
130 goto out;
132 if (filename == NULL && dfd != AT_FDCWD) {
133 struct fd f;
135 if (flags & AT_SYMLINK_NOFOLLOW)
136 goto out;
138 f = fdget(dfd);
139 error = -EBADF;
140 if (!f.file)
141 goto out;
143 error = utimes_common(&f.file->f_path, times);
144 fdput(f);
145 } else {
146 struct path path;
147 int lookup_flags = 0;
149 if (!(flags & AT_SYMLINK_NOFOLLOW))
150 lookup_flags |= LOOKUP_FOLLOW;
151 retry:
152 error = user_path_at(dfd, filename, lookup_flags, &path);
153 if (error)
154 goto out;
156 error = utimes_common(&path, times);
157 path_put(&path);
158 if (retry_estale(error, lookup_flags)) {
159 lookup_flags |= LOOKUP_REVAL;
160 goto retry;
164 out:
165 return error;
168 SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
169 struct timespec __user *, utimes, int, flags)
171 struct timespec64 tstimes[2];
173 if (utimes) {
174 if ((get_timespec64(&tstimes[0], &utimes[0]) ||
175 get_timespec64(&tstimes[1], &utimes[1])))
176 return -EFAULT;
178 /* Nothing to do, we must not even check the path. */
179 if (tstimes[0].tv_nsec == UTIME_OMIT &&
180 tstimes[1].tv_nsec == UTIME_OMIT)
181 return 0;
184 return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
187 static long do_futimesat(int dfd, const char __user *filename,
188 struct timeval __user *utimes)
190 struct timeval times[2];
191 struct timespec64 tstimes[2];
193 if (utimes) {
194 if (copy_from_user(&times, utimes, sizeof(times)))
195 return -EFAULT;
197 /* This test is needed to catch all invalid values. If we
198 would test only in do_utimes we would miss those invalid
199 values truncated by the multiplication with 1000. Note
200 that we also catch UTIME_{NOW,OMIT} here which are only
201 valid for utimensat. */
202 if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
203 times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
204 return -EINVAL;
206 tstimes[0].tv_sec = times[0].tv_sec;
207 tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
208 tstimes[1].tv_sec = times[1].tv_sec;
209 tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
212 return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
216 SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
217 struct timeval __user *, utimes)
219 return do_futimesat(dfd, filename, utimes);
222 SYSCALL_DEFINE2(utimes, char __user *, filename,
223 struct timeval __user *, utimes)
225 return do_futimesat(AT_FDCWD, filename, utimes);
228 #ifdef CONFIG_COMPAT
230 * Not all architectures have sys_utime, so implement this in terms
231 * of sys_utimes.
233 COMPAT_SYSCALL_DEFINE2(utime, const char __user *, filename,
234 struct compat_utimbuf __user *, t)
236 struct timespec64 tv[2];
238 if (t) {
239 if (get_user(tv[0].tv_sec, &t->actime) ||
240 get_user(tv[1].tv_sec, &t->modtime))
241 return -EFAULT;
242 tv[0].tv_nsec = 0;
243 tv[1].tv_nsec = 0;
245 return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
248 COMPAT_SYSCALL_DEFINE4(utimensat, unsigned int, dfd, const char __user *, filename, struct compat_timespec __user *, t, int, flags)
250 struct timespec64 tv[2];
252 if (t) {
253 if (compat_get_timespec64(&tv[0], &t[0]) ||
254 compat_get_timespec64(&tv[1], &t[1]))
255 return -EFAULT;
257 if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
258 return 0;
260 return do_utimes(dfd, filename, t ? tv : NULL, flags);
263 static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
264 struct compat_timeval __user *t)
266 struct timespec64 tv[2];
268 if (t) {
269 if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
270 get_user(tv[0].tv_nsec, &t[0].tv_usec) ||
271 get_user(tv[1].tv_sec, &t[1].tv_sec) ||
272 get_user(tv[1].tv_nsec, &t[1].tv_usec))
273 return -EFAULT;
274 if (tv[0].tv_nsec >= 1000000 || tv[0].tv_nsec < 0 ||
275 tv[1].tv_nsec >= 1000000 || tv[1].tv_nsec < 0)
276 return -EINVAL;
277 tv[0].tv_nsec *= 1000;
278 tv[1].tv_nsec *= 1000;
280 return do_utimes(dfd, filename, t ? tv : NULL, 0);
283 COMPAT_SYSCALL_DEFINE3(futimesat, unsigned int, dfd,
284 const char __user *, filename,
285 struct compat_timeval __user *, t)
287 return do_compat_futimesat(dfd, filename, t);
290 COMPAT_SYSCALL_DEFINE2(utimes, const char __user *, filename, struct compat_timeval __user *, t)
292 return do_compat_futimesat(AT_FDCWD, filename, t);
294 #endif