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Alexey Dobriyan82b05472006-09-30 23:27:22 -07001#include <linux/compiler.h>
Ulrich Drepper1c710c82007-05-08 00:33:25 -07002#include <linux/file.h>
Alexey Dobriyan82b05472006-09-30 23:27:22 -07003#include <linux/fs.h>
4#include <linux/linkage.h>
Dave Hansen74f9fdf2008-02-15 14:37:42 -08005#include <linux/mount.h>
Alexey Dobriyan82b05472006-09-30 23:27:22 -07006#include <linux/namei.h>
Al Viro914e2632006-10-18 13:55:46 -04007#include <linux/sched.h>
Ulrich Drepper1c710c82007-05-08 00:33:25 -07008#include <linux/stat.h>
Alexey Dobriyan82b05472006-09-30 23:27:22 -07009#include <linux/utime.h>
Adrian Bunk12c2ab52008-02-06 01:36:47 -080010#include <linux/syscalls.h>
Alexey Dobriyan82b05472006-09-30 23:27:22 -070011#include <asm/uaccess.h>
12#include <asm/unistd.h>
13
14#ifdef __ARCH_WANT_SYS_UTIME
15
16/*
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
20 * need it).
21 */
22
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.
26 */
Heiko Carstens003d7ab2009-01-14 14:14:21 +010027SYSCALL_DEFINE2(utime, char __user *, filename, struct utimbuf __user *, times)
Alexey Dobriyan82b05472006-09-30 23:27:22 -070028{
Ulrich Drepper1c710c82007-05-08 00:33:25 -070029 struct timespec tv[2];
Alexey Dobriyan82b05472006-09-30 23:27:22 -070030
Alexey Dobriyan82b05472006-09-30 23:27:22 -070031 if (times) {
Ulrich Drepper1c710c82007-05-08 00:33:25 -070032 if (get_user(tv[0].tv_sec, &times->actime) ||
33 get_user(tv[1].tv_sec, &times->modtime))
34 return -EFAULT;
35 tv[0].tv_nsec = 0;
36 tv[1].tv_nsec = 0;
Alexey Dobriyan82b05472006-09-30 23:27:22 -070037 }
Ulrich Drepper1c710c82007-05-08 00:33:25 -070038 return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
Alexey Dobriyan82b05472006-09-30 23:27:22 -070039}
40
41#endif
42
Miklos Szeredi043f46f2007-10-16 23:27:07 -070043static bool nsec_valid(long nsec)
44{
Michael Kerrisk4cca9222008-06-09 21:16:08 -070045 if (nsec == UTIME_OMIT || nsec == UTIME_NOW)
Miklos Szeredi043f46f2007-10-16 23:27:07 -070046 return true;
47
48 return nsec >= 0 && nsec <= 999999999;
49}
50
Miklos Szeredie9b76fe2008-07-01 15:01:27 +020051static int utimes_common(struct path *path, struct timespec *times)
Alexey Dobriyan82b05472006-09-30 23:27:22 -070052{
53 int error;
Alexey Dobriyan82b05472006-09-30 23:27:22 -070054 struct iattr newattrs;
Miklos Szeredie9b76fe2008-07-01 15:01:27 +020055 struct inode *inode = path->dentry->d_inode;
Alexey Dobriyan82b05472006-09-30 23:27:22 -070056
Miklos Szeredie9b76fe2008-07-01 15:01:27 +020057 error = mnt_want_write(path->mnt);
Dave Hansen74f9fdf2008-02-15 14:37:42 -080058 if (error)
Miklos Szeredie9b76fe2008-07-01 15:01:27 +020059 goto out;
Alexey Dobriyan82b05472006-09-30 23:27:22 -070060
Michael Kerrisk12fd0d32008-06-09 21:16:07 -070061 if (times && times[0].tv_nsec == UTIME_NOW &&
62 times[1].tv_nsec == UTIME_NOW)
63 times = NULL;
64
Alexey Dobriyan82b05472006-09-30 23:27:22 -070065 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
66 if (times) {
Ulrich Drepper1c710c82007-05-08 00:33:25 -070067 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;
73 }
74
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;
81 }
Michael Kerrisk4cca9222008-06-09 21:16:08 -070082 /*
Miklos Szeredi9767d742008-07-01 15:01:26 +020083 * Tell inode_change_ok(), that this is an explicit time
84 * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
85 * were used.
Michael Kerrisk4cca9222008-06-09 21:16:08 -070086 */
Miklos Szeredi9767d742008-07-01 15:01:26 +020087 newattrs.ia_valid |= ATTR_TIMES_SET;
Michael Kerrisk4cca9222008-06-09 21:16:08 -070088 } else {
Michael Kerrisk4cca9222008-06-09 21:16:08 -070089 /*
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.
93 */
Alexey Dobriyan82b05472006-09-30 23:27:22 -070094 error = -EACCES;
95 if (IS_IMMUTABLE(inode))
Dave Hansen74f9fdf2008-02-15 14:37:42 -080096 goto mnt_drop_write_and_out;
Alexey Dobriyan82b05472006-09-30 23:27:22 -070097
Serge E. Hallyn2e149672011-03-23 16:43:26 -070098 if (!inode_owner_or_capable(inode)) {
Al Virof419a2e2008-07-22 00:07:17 -040099 error = inode_permission(inode, MAY_WRITE);
Michael Kerriskc70f8442008-06-09 21:16:09 -0700100 if (error)
101 goto mnt_drop_write_and_out;
Linus Torvalds1e5de282007-07-08 12:02:55 -0700102 }
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700103 }
104 mutex_lock(&inode->i_mutex);
Miklos Szeredie9b76fe2008-07-01 15:01:27 +0200105 error = notify_change(path->dentry, &newattrs);
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700106 mutex_unlock(&inode->i_mutex);
Miklos Szeredie9b76fe2008-07-01 15:01:27 +0200107
Dave Hansen74f9fdf2008-02-15 14:37:42 -0800108mnt_drop_write_and_out:
Miklos Szeredie9b76fe2008-07-01 15:01:27 +0200109 mnt_drop_write(path->mnt);
110out:
111 return error;
112}
113
114/*
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)
120 *
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
123 * starting point.
124 *
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.
128 */
David Howellsc7887322010-08-11 11:26:22 +0100129long do_utimes(int dfd, const char __user *filename, struct timespec *times,
130 int flags)
Miklos Szeredie9b76fe2008-07-01 15:01:27 +0200131{
132 int error = -EINVAL;
133
134 if (times && (!nsec_valid(times[0].tv_nsec) ||
135 !nsec_valid(times[1].tv_nsec))) {
136 goto out;
137 }
138
139 if (flags & ~AT_SYMLINK_NOFOLLOW)
140 goto out;
141
142 if (filename == NULL && dfd != AT_FDCWD) {
Al Viro2903ff02012-08-28 12:52:22 -0400143 struct fd f;
Miklos Szeredie9b76fe2008-07-01 15:01:27 +0200144
145 if (flags & AT_SYMLINK_NOFOLLOW)
146 goto out;
147
Al Viro2903ff02012-08-28 12:52:22 -0400148 f = fdget(dfd);
Miklos Szeredie9b76fe2008-07-01 15:01:27 +0200149 error = -EBADF;
Al Viro2903ff02012-08-28 12:52:22 -0400150 if (!f.file)
Miklos Szeredie9b76fe2008-07-01 15:01:27 +0200151 goto out;
152
Al Viro2903ff02012-08-28 12:52:22 -0400153 error = utimes_common(&f.file->f_path, times);
154 fdput(f);
Miklos Szeredie9b76fe2008-07-01 15:01:27 +0200155 } else {
Al Viro2d8f3032008-07-22 09:59:21 -0400156 struct path path;
Miklos Szeredie9b76fe2008-07-01 15:01:27 +0200157 int lookup_flags = 0;
158
159 if (!(flags & AT_SYMLINK_NOFOLLOW))
160 lookup_flags |= LOOKUP_FOLLOW;
Jeff Laytona69201d2012-12-11 12:10:14 -0500161retry:
Al Viro2d8f3032008-07-22 09:59:21 -0400162 error = user_path_at(dfd, filename, lookup_flags, &path);
Miklos Szeredie9b76fe2008-07-01 15:01:27 +0200163 if (error)
164 goto out;
165
Al Viro2d8f3032008-07-22 09:59:21 -0400166 error = utimes_common(&path, times);
167 path_put(&path);
Jeff Laytona69201d2012-12-11 12:10:14 -0500168 if (retry_estale(error, lookup_flags)) {
169 lookup_flags |= LOOKUP_REVAL;
170 goto retry;
171 }
Miklos Szeredie9b76fe2008-07-01 15:01:27 +0200172 }
173
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700174out:
175 return error;
176}
177
David Howellsc7887322010-08-11 11:26:22 +0100178SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
Heiko Carstens6559eed82009-01-14 14:14:32 +0100179 struct timespec __user *, utimes, int, flags)
Ulrich Drepper1c710c82007-05-08 00:33:25 -0700180{
181 struct timespec tstimes[2];
182
183 if (utimes) {
184 if (copy_from_user(&tstimes, utimes, sizeof(tstimes)))
185 return -EFAULT;
Ulrich Drepper1c710c82007-05-08 00:33:25 -0700186
187 /* Nothing to do, we must not even check the path. */
188 if (tstimes[0].tv_nsec == UTIME_OMIT &&
189 tstimes[1].tv_nsec == UTIME_OMIT)
190 return 0;
191 }
192
193 return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
194}
195
David Howellsc7887322010-08-11 11:26:22 +0100196SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
Heiko Carstens6559eed82009-01-14 14:14:32 +0100197 struct timeval __user *, utimes)
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700198{
199 struct timeval times[2];
Ulrich Drepper1c710c82007-05-08 00:33:25 -0700200 struct timespec tstimes[2];
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700201
Ulrich Drepper1c710c82007-05-08 00:33:25 -0700202 if (utimes) {
203 if (copy_from_user(&times, utimes, sizeof(times)))
204 return -EFAULT;
205
206 /* This test is needed to catch all invalid values. If we
207 would test only in do_utimes we would miss those invalid
208 values truncated by the multiplication with 1000. Note
209 that we also catch UTIME_{NOW,OMIT} here which are only
210 valid for utimensat. */
211 if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
212 times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
213 return -EINVAL;
214
215 tstimes[0].tv_sec = times[0].tv_sec;
216 tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
217 tstimes[1].tv_sec = times[1].tv_sec;
218 tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
219 }
220
221 return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700222}
223
Heiko Carstens003d7ab2009-01-14 14:14:21 +0100224SYSCALL_DEFINE2(utimes, char __user *, filename,
225 struct timeval __user *, utimes)
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700226{
227 return sys_futimesat(AT_FDCWD, filename, utimes);
228}