File: /usr/src/linux/fs/umsdos/ioctl.c
1 /*
2 * linux/fs/umsdos/ioctl.c
3 *
4 * Written 1993 by Jacques Gelinas
5 *
6 * Extended MS-DOS ioctl directory handling functions
7 */
8
9 #include <asm/uaccess.h>
10 #include <linux/errno.h>
11 #include <linux/mm.h>
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/fs.h>
15 #include <linux/msdos_fs.h>
16 #include <linux/umsdos_fs.h>
17
18 struct UMSDOS_DIR_ONCE {
19 struct dirent *ent;
20 int count;
21 };
22
23 /*
24 * Record a single entry the first call.
25 * Return -EINVAL the next one.
26 */
27 static int umsdos_ioctl_fill (
28 void *buf,
29 const char *name,
30 int name_len,
31 loff_t offset,
32 ino_t ino,
33 unsigned type)
34 {
35 int ret = -EINVAL;
36 struct UMSDOS_DIR_ONCE *d = (struct UMSDOS_DIR_ONCE *) buf;
37
38 if (d->count == 0) {
39 copy_to_user (d->ent->d_name, name, name_len);
40 put_user ('\0', d->ent->d_name + name_len);
41 put_user (name_len, &d->ent->d_reclen);
42 put_user (ino, &d->ent->d_ino);
43 put_user (offset, &d->ent->d_off);
44 d->count = 1;
45 ret = 0;
46 }
47 return ret;
48 }
49
50
51 /*
52 * Perform special function on a directory
53 */
54 /* #Specification: ioctl / prototypes
55 * The official prototype for the umsdos ioctl on directory
56 * is:
57 *
58 * int ioctl (
59 * int fd, // File handle of the directory
60 * int cmd, // command
61 * struct umsdos_ioctl *data)
62 *
63 * The struct and the commands are defined in linux/umsdos_fs.h.
64 *
65 * umsdos_progs/umsdosio.c provide an interface in C++ to all
66 * these ioctl. umsdos_progs/udosctl is a small utility showing
67 * all this.
68 *
69 * These ioctl generally allow one to work on the EMD or the
70 * DOS directory independently. These are essential to implement
71 * the synchronise.
72 */
73 int UMSDOS_ioctl_dir(struct inode *dir, struct file *filp, unsigned int cmd,
74 unsigned long data_ptr)
75 {
76 struct dentry *dentry = filp->f_dentry;
77 struct umsdos_ioctl *idata = (struct umsdos_ioctl *) data_ptr;
78 int ret;
79 struct umsdos_ioctl data;
80
81 Printk(("UMSDOS_ioctl_dir: %s/%s, cmd=%d, data=%08lx\n",
82 dentry->d_parent->d_name.name, dentry->d_name.name, cmd, data_ptr));
83
84 /* forward non-umsdos ioctls - this hopefully doesn't cause conflicts */
85 if (cmd != UMSDOS_GETVERSION
86 && cmd != UMSDOS_READDIR_DOS
87 && cmd != UMSDOS_READDIR_EMD
88 && cmd != UMSDOS_INIT_EMD
89 && cmd != UMSDOS_CREAT_EMD
90 && cmd != UMSDOS_RENAME_DOS
91 && cmd != UMSDOS_UNLINK_EMD
92 && cmd != UMSDOS_UNLINK_DOS
93 && cmd != UMSDOS_RMDIR_DOS
94 && cmd != UMSDOS_STAT_DOS
95 && cmd != UMSDOS_DOS_SETUP)
96 return fat_dir_ioctl (dir, filp, cmd, data_ptr);
97
98 /* #Specification: ioctl / access
99 * Only root (effective id) is allowed to do IOCTL on directory
100 * in UMSDOS. EPERM is returned for other user.
101 */
102 /*
103 * Well, not all cases require write access, but it simplifies
104 * the code, and let's face it, there is only one client (umssync)
105 * for all this.
106 */
107 ret = verify_area (VERIFY_WRITE, (void *) data_ptr,
108 sizeof (struct umsdos_ioctl));
109 if (ret < 0)
110 goto out;
111
112 ret = -EPERM;
113 if (current->euid != 0 && cmd != UMSDOS_GETVERSION)
114 goto out;
115
116 ret = -EINVAL;
117 if (cmd == UMSDOS_GETVERSION) {
118 /* #Specification: ioctl / UMSDOS_GETVERSION
119 * The field version and release of the structure
120 * umsdos_ioctl are filled with the version and release
121 * number of the fs code in the kernel. This will allow
122 * some form of checking. Users won't be able to run
123 * incompatible utility such as the synchroniser (umssync).
124 * umsdos_progs/umsdosio.c enforce this checking.
125 *
126 * Return always 0.
127 */
128 put_user (UMSDOS_VERSION, &idata->version);
129 put_user (UMSDOS_RELEASE, &idata->release);
130 ret = 0;
131 goto out;
132 }
133 if (cmd == UMSDOS_READDIR_DOS) {
134 /* #Specification: ioctl / UMSDOS_READDIR_DOS
135 * One entry is read from the DOS directory at the current
136 * file position. The entry is put as is in the dos_dirent
137 * field of struct umsdos_ioctl.
138 *
139 * Return > 0 if success.
140 */
141 struct UMSDOS_DIR_ONCE bufk;
142
143 bufk.count = 0;
144 bufk.ent = &idata->dos_dirent;
145
146 fat_readdir (filp, &bufk, umsdos_ioctl_fill);
147
148 ret = bufk.count == 1 ? 1 : 0;
149 goto out;
150 }
151 if (cmd == UMSDOS_READDIR_EMD) {
152 /* #Specification: ioctl / UMSDOS_READDIR_EMD
153 * One entry is read from the EMD at the current
154 * file position. The entry is put as is in the umsdos_dirent
155 * field of struct umsdos_ioctl. The corresponding mangled
156 * DOS entry name is put in the dos_dirent field.
157 *
158 * All entries are read including hidden links. Blank
159 * entries are skipped.
160 *
161 * Return > 0 if success.
162 */
163 struct dentry *demd;
164 loff_t pos = filp->f_pos;
165
166 /* The absence of the EMD is simply seen as an EOF */
167 demd = umsdos_get_emd_dentry(dentry);
168 ret = PTR_ERR(demd);
169 if (IS_ERR(demd))
170 goto out;
171 ret = 0;
172 if (!demd->d_inode)
173 goto read_dput;
174
175 while (pos < demd->d_inode->i_size) {
176 off_t f_pos = pos;
177 struct umsdos_dirent entry;
178 struct umsdos_info info;
179
180 ret = umsdos_emd_dir_readentry (demd, &pos, &entry);
181
182 if (ret == -ENAMETOOLONG) {
183 printk (KERN_INFO "Fixing EMD entry with invalid size -- zeroing out\n");
184 memset (&info, 0, sizeof (info));
185 info.f_pos = f_pos;
186 info.recsize = UMSDOS_REC_SIZE;
187 ret = umsdos_writeentry (dentry, &info, 1);
188 continue;
189 }
190
191 if (ret)
192 break;
193 if (entry.name_len <= 0)
194 continue;
195
196 umsdos_parse (entry.name, entry.name_len, &info);
197 info.f_pos = f_pos;
198 umsdos_manglename (&info);
199 ret = -EFAULT;
200 if (copy_to_user (&idata->umsdos_dirent, &entry,
201 sizeof (entry)))
202 break;
203 if (copy_to_user (&idata->dos_dirent.d_name,
204 info.fake.fname,
205 info.fake.len + 1))
206 break;
207 ret = entry.name_len;
208 break;
209 }
210 /* update the original f_pos */
211 filp->f_pos = pos;
212 read_dput:
213 d_drop(demd);
214 dput(demd);
215 goto out;
216 }
217 if (cmd == UMSDOS_INIT_EMD) {
218 /* #Specification: ioctl / UMSDOS_INIT_EMD
219 * The UMSDOS_INIT_EMD command makes sure the EMD
220 * exists for a directory. If it does not, it is
221 * created. Also, it makes sure the directory function
222 * table (struct inode_operations) is set to the UMSDOS
223 * semantic. This mean that umssync may be applied to
224 * an "opened" msdos directory, and it will change behavior
225 * on the fly.
226 *
227 * Return 0 if success.
228 */
229
230 ret = umsdos_make_emd(dentry);
231 Printk(("UMSDOS_ioctl_dir: INIT_EMD %s/%s, ret=%d\n",
232 dentry->d_parent->d_name.name, dentry->d_name.name, ret));
233 umsdos_setup_dir (dentry);
234 goto out;
235 }
236
237 ret = -EFAULT;
238 if (copy_from_user (&data, idata, sizeof (data)))
239 goto out;
240
241 if (cmd == UMSDOS_CREAT_EMD) {
242 /* #Specification: ioctl / UMSDOS_CREAT_EMD
243 * The umsdos_dirent field of the struct umsdos_ioctl is used
244 * as is to create a new entry in the EMD of the directory.
245 * The DOS directory is not modified.
246 * No validation is done (yet).
247 *
248 * Return 0 if success.
249 */
250 struct umsdos_info info;
251
252 /* This makes sure info.entry and info in general
253 * is correctly initialised
254 */
255 memcpy (&info.entry, &data.umsdos_dirent,
256 sizeof (data.umsdos_dirent));
257 umsdos_parse (data.umsdos_dirent.name
258 ,data.umsdos_dirent.name_len, &info);
259 ret = umsdos_newentry (dentry, &info);
260 goto out;
261 }
262 else if (cmd == UMSDOS_RENAME_DOS) {
263 struct dentry *old_dentry, *new_dentry; /* FIXME */
264
265 /* #Specification: ioctl / UMSDOS_RENAME_DOS
266 * A file or directory is renamed in a DOS directory
267 * (not moved across directory). The source name
268 * is in the dos_dirent.name field and the destination
269 * is in umsdos_dirent.name field.
270 *
271 * This ioctl allows umssync to rename a mangled file
272 * name before syncing it back in the EMD.
273 */
274 old_dentry = umsdos_lookup_dentry (dentry,
275 data.dos_dirent.d_name,
276 data.dos_dirent.d_reclen ,1);
277 ret = PTR_ERR(old_dentry);
278 if (IS_ERR(old_dentry))
279 goto out;
280 new_dentry = umsdos_lookup_dentry (dentry,
281 data.umsdos_dirent.name,
282 data.umsdos_dirent.name_len, 1);
283 ret = PTR_ERR(new_dentry);
284 if (!IS_ERR(new_dentry)) {
285 printk("umsdos_ioctl: renaming %s/%s to %s/%s\n",
286 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
287 new_dentry->d_parent->d_name.name, new_dentry->d_name.name);
288 ret = msdos_rename (dir, old_dentry, dir, new_dentry);
289 d_drop(new_dentry);
290 d_drop(old_dentry);
291 dput(new_dentry);
292 }
293 dput(old_dentry);
294 goto out;
295 }
296 else if (cmd == UMSDOS_UNLINK_EMD) {
297 /* #Specification: ioctl / UMSDOS_UNLINK_EMD
298 * The umsdos_dirent field of the struct umsdos_ioctl is used
299 * as is to remove an entry from the EMD of the directory.
300 * No validation is done (yet). The mode field is used
301 * to validate S_ISDIR or S_ISREG.
302 *
303 * Return 0 if success.
304 */
305 struct umsdos_info info;
306
307 /* This makes sure info.entry and info in general
308 * is correctly initialised
309 */
310 memcpy (&info.entry, &data.umsdos_dirent,
311 sizeof (data.umsdos_dirent));
312 umsdos_parse (data.umsdos_dirent.name,
313 data.umsdos_dirent.name_len, &info);
314 ret = umsdos_delentry (dentry, &info,
315 S_ISDIR (data.umsdos_dirent.mode));
316 if (ret) {
317 printk(KERN_WARNING
318 "umsdos_ioctl: delentry %s/%s failed, ret=%d\n",
319 dentry->d_name.name, info.entry.name, ret);
320 }
321 goto out;
322 }
323 else if (cmd == UMSDOS_UNLINK_DOS) {
324 struct dentry *temp;
325
326 /* #Specification: ioctl / UMSDOS_UNLINK_DOS
327 * The dos_dirent field of the struct umsdos_ioctl is used to
328 * execute a msdos_unlink operation. The d_name and d_reclen
329 * fields are used.
330 *
331 * Return 0 if success.
332 */
333 temp = umsdos_lookup_dentry(dentry, data.dos_dirent.d_name,
334 data.dos_dirent.d_reclen, 1);
335 ret = PTR_ERR(temp);
336 if (IS_ERR(temp))
337 goto out;
338 ret = -ENOENT;
339 if (temp->d_inode) {
340 ret = -EISDIR;
341 if (!S_ISDIR(temp->d_inode->i_mode))
342 ret = msdos_unlink (dir, temp);
343 if (!ret)
344 d_delete(temp);
345 }
346 dput (temp);
347 goto out;
348 }
349 else if (cmd == UMSDOS_RMDIR_DOS) {
350 struct dentry *temp;
351
352 /* #Specification: ioctl / UMSDOS_RMDIR_DOS
353 * The dos_dirent field of the struct umsdos_ioctl is used to
354 * execute a msdos_rmdir operation. The d_name and d_reclen
355 * fields are used.
356 *
357 * Return 0 if success.
358 */
359 temp = umsdos_lookup_dentry(dentry, data.dos_dirent.d_name,
360 data.dos_dirent.d_reclen, 1);
361 ret = PTR_ERR(temp);
362 if (IS_ERR(temp))
363 goto out;
364 ret = -ENOENT;
365 if (temp->d_inode) {
366 ret = -ENOTDIR;
367 if (S_ISDIR(temp->d_inode->i_mode))
368 ret = msdos_rmdir (dir, temp);
369 if (!ret)
370 d_delete(temp);
371 }
372 dput (temp);
373 goto out;
374
375 } else if (cmd == UMSDOS_STAT_DOS) {
376 /* #Specification: ioctl / UMSDOS_STAT_DOS
377 * The dos_dirent field of the struct umsdos_ioctl is
378 * used to execute a stat operation in the DOS directory.
379 * The d_name and d_reclen fields are used.
380 *
381 * The following field of umsdos_ioctl.stat are filled.
382 *
383 * st_ino,st_mode,st_size,st_atime,st_mtime,st_ctime,
384 * Return 0 if success.
385 */
386 struct dentry *dret;
387 struct inode *inode;
388
389 dret = umsdos_lookup_dentry(dentry, data.dos_dirent.d_name,
390 data.dos_dirent.d_reclen, 1);
391 ret = PTR_ERR(dret);
392 if (IS_ERR(dret))
393 goto out;
394 ret = -ENOENT;
395 inode = dret->d_inode;
396 if (inode) {
397 data.stat.st_ino = inode->i_ino;
398 data.stat.st_mode = inode->i_mode;
399 data.stat.st_size = inode->i_size;
400 data.stat.st_atime = inode->i_atime;
401 data.stat.st_ctime = inode->i_ctime;
402 data.stat.st_mtime = inode->i_mtime;
403 ret = -EFAULT;
404 if (!copy_to_user (&idata->stat, &data.stat,
405 sizeof (data.stat)))
406 ret = 0;
407 }
408 dput(dret);
409 goto out;
410 }
411 else if (cmd == UMSDOS_DOS_SETUP) {
412 /* #Specification: ioctl / UMSDOS_DOS_SETUP
413 * The UMSDOS_DOS_SETUP ioctl allow changing the
414 * default permission of the MS-DOS filesystem driver
415 * on the fly. The MS-DOS driver applies global permissions
416 * to every file and directory. Normally these permissions
417 * are controlled by a mount option. This is not
418 * available for root partition, so a special utility
419 * (umssetup) is provided to do this, normally in
420 * /etc/rc.local.
421 *
422 * Be aware that this applies ONLY to MS-DOS directories
423 * (those without EMD --linux-.---). Umsdos directory
424 * have independent (standard) permission for each
425 * and every file.
426 *
427 * The field umsdos_dirent provide the information needed.
428 * umsdos_dirent.uid and gid sets the owner and group.
429 * umsdos_dirent.mode set the permissions flags.
430 */
431 dir->i_sb->u.msdos_sb.options.fs_uid = data.umsdos_dirent.uid;
432 dir->i_sb->u.msdos_sb.options.fs_gid = data.umsdos_dirent.gid;
433 dir->i_sb->u.msdos_sb.options.fs_umask = data.umsdos_dirent.mode;
434 ret = 0;
435 }
436 out:
437 Printk (("ioctl %d, returning %d\n", cmd, ret));
438 return ret;
439 }
440