blob: af059d5cb485df8289eda123380f4937c0c7b77c [file] [log] [blame]
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 */
Ulrich Drepper1c710c82007-05-08 00:33:25 -070027asmlinkage long sys_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 Szeredi02c6be62008-05-01 04:34:45 -070043static bool nsec_special(long nsec)
44{
45 return nsec == UTIME_OMIT || nsec == UTIME_NOW;
46}
47
Miklos Szeredi043f46f2007-10-16 23:27:07 -070048static bool nsec_valid(long nsec)
49{
Miklos Szeredi02c6be62008-05-01 04:34:45 -070050 if (nsec_special(nsec))
Miklos Szeredi043f46f2007-10-16 23:27:07 -070051 return true;
52
53 return nsec >= 0 && nsec <= 999999999;
54}
55
Alexey Dobriyan82b05472006-09-30 23:27:22 -070056/* 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.
59 */
Ulrich Drepper1c710c82007-05-08 00:33:25 -070060long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags)
Alexey Dobriyan82b05472006-09-30 23:27:22 -070061{
62 int error;
63 struct nameidata nd;
Ulrich Drepper1c710c82007-05-08 00:33:25 -070064 struct dentry *dentry;
65 struct inode *inode;
Alexey Dobriyan82b05472006-09-30 23:27:22 -070066 struct iattr newattrs;
Ulrich Drepper1c710c82007-05-08 00:33:25 -070067 struct file *f = NULL;
Dave Hansen74f9fdf2008-02-15 14:37:42 -080068 struct vfsmount *mnt;
Alexey Dobriyan82b05472006-09-30 23:27:22 -070069
Ulrich Drepper1c710c82007-05-08 00:33:25 -070070 error = -EINVAL;
Miklos Szeredi043f46f2007-10-16 23:27:07 -070071 if (times && (!nsec_valid(times[0].tv_nsec) ||
72 !nsec_valid(times[1].tv_nsec))) {
73 goto out;
74 }
75
Ulrich Drepper1c710c82007-05-08 00:33:25 -070076 if (flags & ~AT_SYMLINK_NOFOLLOW)
Alexey Dobriyan82b05472006-09-30 23:27:22 -070077 goto out;
Ulrich Drepper1c710c82007-05-08 00:33:25 -070078
79 if (filename == NULL && dfd != AT_FDCWD) {
80 error = -EINVAL;
81 if (flags & AT_SYMLINK_NOFOLLOW)
82 goto out;
83
84 error = -EBADF;
85 f = fget(dfd);
86 if (!f)
87 goto out;
88 dentry = f->f_path.dentry;
Dave Hansen74f9fdf2008-02-15 14:37:42 -080089 mnt = f->f_path.mnt;
Ulrich Drepper1c710c82007-05-08 00:33:25 -070090 } else {
91 error = __user_walk_fd(dfd, filename, (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW, &nd);
92 if (error)
93 goto out;
94
Jan Blunck4ac91372008-02-14 19:34:32 -080095 dentry = nd.path.dentry;
Dave Hansen74f9fdf2008-02-15 14:37:42 -080096 mnt = nd.path.mnt;
Ulrich Drepper1c710c82007-05-08 00:33:25 -070097 }
98
99 inode = dentry->d_inode;
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700100
Dave Hansen74f9fdf2008-02-15 14:37:42 -0800101 error = mnt_want_write(mnt);
102 if (error)
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700103 goto dput_and_out;
104
105 /* Don't worry, the checks are done in inode_change_ok() */
106 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
107 if (times) {
108 error = -EPERM;
109 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
Dave Hansen74f9fdf2008-02-15 14:37:42 -0800110 goto mnt_drop_write_and_out;
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700111
Ulrich Drepper1c710c82007-05-08 00:33:25 -0700112 if (times[0].tv_nsec == UTIME_OMIT)
113 newattrs.ia_valid &= ~ATTR_ATIME;
114 else if (times[0].tv_nsec != UTIME_NOW) {
115 newattrs.ia_atime.tv_sec = times[0].tv_sec;
116 newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
117 newattrs.ia_valid |= ATTR_ATIME_SET;
118 }
119
120 if (times[1].tv_nsec == UTIME_OMIT)
121 newattrs.ia_valid &= ~ATTR_MTIME;
122 else if (times[1].tv_nsec != UTIME_NOW) {
123 newattrs.ia_mtime.tv_sec = times[1].tv_sec;
124 newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
125 newattrs.ia_valid |= ATTR_MTIME_SET;
126 }
Miklos Szeredi02c6be62008-05-01 04:34:45 -0700127 }
128
129 /*
130 * If times is NULL or both times are either UTIME_OMIT or
131 * UTIME_NOW, then need to check permissions, because
132 * inode_change_ok() won't do it.
133 */
134 if (!times || (nsec_special(times[0].tv_nsec) &&
135 nsec_special(times[1].tv_nsec))) {
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700136 error = -EACCES;
137 if (IS_IMMUTABLE(inode))
Dave Hansen74f9fdf2008-02-15 14:37:42 -0800138 goto mnt_drop_write_and_out;
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700139
Satyam Sharma3bd858a2007-07-17 15:00:08 +0530140 if (!is_owner_or_cap(inode)) {
Linus Torvalds1e5de282007-07-08 12:02:55 -0700141 if (f) {
142 if (!(f->f_mode & FMODE_WRITE))
Dave Hansen74f9fdf2008-02-15 14:37:42 -0800143 goto mnt_drop_write_and_out;
Linus Torvalds1e5de282007-07-08 12:02:55 -0700144 } else {
145 error = vfs_permission(&nd, MAY_WRITE);
146 if (error)
Dave Hansen74f9fdf2008-02-15 14:37:42 -0800147 goto mnt_drop_write_and_out;
Linus Torvalds1e5de282007-07-08 12:02:55 -0700148 }
149 }
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700150 }
151 mutex_lock(&inode->i_mutex);
Ulrich Drepper1c710c82007-05-08 00:33:25 -0700152 error = notify_change(dentry, &newattrs);
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700153 mutex_unlock(&inode->i_mutex);
Dave Hansen74f9fdf2008-02-15 14:37:42 -0800154mnt_drop_write_and_out:
155 mnt_drop_write(mnt);
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700156dput_and_out:
Ulrich Drepper1c710c82007-05-08 00:33:25 -0700157 if (f)
158 fput(f);
159 else
Jan Blunck1d957f92008-02-14 19:34:35 -0800160 path_put(&nd.path);
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700161out:
162 return error;
163}
164
Ulrich Drepper1c710c82007-05-08 00:33:25 -0700165asmlinkage long sys_utimensat(int dfd, char __user *filename, struct timespec __user *utimes, int flags)
166{
167 struct timespec tstimes[2];
168
169 if (utimes) {
170 if (copy_from_user(&tstimes, utimes, sizeof(tstimes)))
171 return -EFAULT;
172 if ((tstimes[0].tv_nsec == UTIME_OMIT ||
173 tstimes[0].tv_nsec == UTIME_NOW) &&
174 tstimes[0].tv_sec != 0)
175 return -EINVAL;
176 if ((tstimes[1].tv_nsec == UTIME_OMIT ||
177 tstimes[1].tv_nsec == UTIME_NOW) &&
178 tstimes[1].tv_sec != 0)
179 return -EINVAL;
180
181 /* Nothing to do, we must not even check the path. */
182 if (tstimes[0].tv_nsec == UTIME_OMIT &&
183 tstimes[1].tv_nsec == UTIME_OMIT)
184 return 0;
185 }
186
187 return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
188}
189
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700190asmlinkage long sys_futimesat(int dfd, char __user *filename, struct timeval __user *utimes)
191{
192 struct timeval times[2];
Ulrich Drepper1c710c82007-05-08 00:33:25 -0700193 struct timespec tstimes[2];
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700194
Ulrich Drepper1c710c82007-05-08 00:33:25 -0700195 if (utimes) {
196 if (copy_from_user(&times, utimes, sizeof(times)))
197 return -EFAULT;
198
199 /* This test is needed to catch all invalid values. If we
200 would test only in do_utimes we would miss those invalid
201 values truncated by the multiplication with 1000. Note
202 that we also catch UTIME_{NOW,OMIT} here which are only
203 valid for utimensat. */
204 if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
205 times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
206 return -EINVAL;
207
208 tstimes[0].tv_sec = times[0].tv_sec;
209 tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
210 tstimes[1].tv_sec = times[1].tv_sec;
211 tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
212 }
213
214 return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
Alexey Dobriyan82b05472006-09-30 23:27:22 -0700215}
216
217asmlinkage long sys_utimes(char __user *filename, struct timeval __user *utimes)
218{
219 return sys_futimesat(AT_FDCWD, filename, utimes);
220}