UBI: add ioctl for map operation
[linux-3.10.git] / drivers / mtd / ubi / cdev.c
1 /*
2  * Copyright (c) International Business Machines Corp., 2006
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12  * the GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17  *
18  * Author: Artem Bityutskiy (Битюцкий Артём)
19  */
20
21 /*
22  * This file includes implementation of UBI character device operations.
23  *
24  * There are two kinds of character devices in UBI: UBI character devices and
25  * UBI volume character devices. UBI character devices allow users to
26  * manipulate whole volumes: create, remove, and re-size them. Volume character
27  * devices provide volume I/O capabilities.
28  *
29  * Major and minor numbers are assigned dynamically to both UBI and volume
30  * character devices.
31  *
32  * Well, there is the third kind of character devices - the UBI control
33  * character device, which allows to manipulate by UBI devices - create and
34  * delete them. In other words, it is used for attaching and detaching MTD
35  * devices.
36  */
37
38 #include <linux/module.h>
39 #include <linux/stat.h>
40 #include <linux/ioctl.h>
41 #include <linux/capability.h>
42 #include <linux/uaccess.h>
43 #include <linux/smp_lock.h>
44 #include <mtd/ubi-user.h>
45 #include <asm/div64.h>
46 #include "ubi.h"
47
48 /**
49  * get_exclusive - get exclusive access to an UBI volume.
50  * @desc: volume descriptor
51  *
52  * This function changes UBI volume open mode to "exclusive". Returns previous
53  * mode value (positive integer) in case of success and a negative error code
54  * in case of failure.
55  */
56 static int get_exclusive(struct ubi_volume_desc *desc)
57 {
58         int users, err;
59         struct ubi_volume *vol = desc->vol;
60
61         spin_lock(&vol->ubi->volumes_lock);
62         users = vol->readers + vol->writers + vol->exclusive;
63         ubi_assert(users > 0);
64         if (users > 1) {
65                 dbg_err("%d users for volume %d", users, vol->vol_id);
66                 err = -EBUSY;
67         } else {
68                 vol->readers = vol->writers = 0;
69                 vol->exclusive = 1;
70                 err = desc->mode;
71                 desc->mode = UBI_EXCLUSIVE;
72         }
73         spin_unlock(&vol->ubi->volumes_lock);
74
75         return err;
76 }
77
78 /**
79  * revoke_exclusive - revoke exclusive mode.
80  * @desc: volume descriptor
81  * @mode: new mode to switch to
82  */
83 static void revoke_exclusive(struct ubi_volume_desc *desc, int mode)
84 {
85         struct ubi_volume *vol = desc->vol;
86
87         spin_lock(&vol->ubi->volumes_lock);
88         ubi_assert(vol->readers == 0 && vol->writers == 0);
89         ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE);
90         vol->exclusive = 0;
91         if (mode == UBI_READONLY)
92                 vol->readers = 1;
93         else if (mode == UBI_READWRITE)
94                 vol->writers = 1;
95         else
96                 vol->exclusive = 1;
97         spin_unlock(&vol->ubi->volumes_lock);
98
99         desc->mode = mode;
100 }
101
102 static int vol_cdev_open(struct inode *inode, struct file *file)
103 {
104         struct ubi_volume_desc *desc;
105         int vol_id = iminor(inode) - 1, mode, ubi_num;
106
107         ubi_num = ubi_major2num(imajor(inode));
108         if (ubi_num < 0)
109                 return ubi_num;
110
111         if (file->f_mode & FMODE_WRITE)
112                 mode = UBI_READWRITE;
113         else
114                 mode = UBI_READONLY;
115
116         dbg_gen("open volume %d, mode %d", vol_id, mode);
117
118         desc = ubi_open_volume(ubi_num, vol_id, mode);
119         if (IS_ERR(desc))
120                 return PTR_ERR(desc);
121
122         file->private_data = desc;
123         return 0;
124 }
125
126 static int vol_cdev_release(struct inode *inode, struct file *file)
127 {
128         struct ubi_volume_desc *desc = file->private_data;
129         struct ubi_volume *vol = desc->vol;
130
131         dbg_gen("release volume %d, mode %d", vol->vol_id, desc->mode);
132
133         if (vol->updating) {
134                 ubi_warn("update of volume %d not finished, volume is damaged",
135                          vol->vol_id);
136                 ubi_assert(!vol->changing_leb);
137                 vol->updating = 0;
138                 vfree(vol->upd_buf);
139         } else if (vol->changing_leb) {
140                 dbg_gen("only %lld of %lld bytes received for atomic LEB change"
141                         " for volume %d:%d, cancel", vol->upd_received,
142                         vol->upd_bytes, vol->ubi->ubi_num, vol->vol_id);
143                 vol->changing_leb = 0;
144                 vfree(vol->upd_buf);
145         }
146
147         ubi_close_volume(desc);
148         return 0;
149 }
150
151 static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin)
152 {
153         struct ubi_volume_desc *desc = file->private_data;
154         struct ubi_volume *vol = desc->vol;
155         loff_t new_offset;
156
157         if (vol->updating) {
158                  /* Update is in progress, seeking is prohibited */
159                 dbg_err("updating");
160                 return -EBUSY;
161         }
162
163         switch (origin) {
164         case 0: /* SEEK_SET */
165                 new_offset = offset;
166                 break;
167         case 1: /* SEEK_CUR */
168                 new_offset = file->f_pos + offset;
169                 break;
170         case 2: /* SEEK_END */
171                 new_offset = vol->used_bytes + offset;
172                 break;
173         default:
174                 return -EINVAL;
175         }
176
177         if (new_offset < 0 || new_offset > vol->used_bytes) {
178                 dbg_err("bad seek %lld", new_offset);
179                 return -EINVAL;
180         }
181
182         dbg_gen("seek volume %d, offset %lld, origin %d, new offset %lld",
183                 vol->vol_id, offset, origin, new_offset);
184
185         file->f_pos = new_offset;
186         return new_offset;
187 }
188
189 static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
190                              loff_t *offp)
191 {
192         struct ubi_volume_desc *desc = file->private_data;
193         struct ubi_volume *vol = desc->vol;
194         struct ubi_device *ubi = vol->ubi;
195         int err, lnum, off, len,  tbuf_size;
196         size_t count_save = count;
197         void *tbuf;
198         uint64_t tmp;
199
200         dbg_gen("read %zd bytes from offset %lld of volume %d",
201                 count, *offp, vol->vol_id);
202
203         if (vol->updating) {
204                 dbg_err("updating");
205                 return -EBUSY;
206         }
207         if (vol->upd_marker) {
208                 dbg_err("damaged volume, update marker is set");
209                 return -EBADF;
210         }
211         if (*offp == vol->used_bytes || count == 0)
212                 return 0;
213
214         if (vol->corrupted)
215                 dbg_gen("read from corrupted volume %d", vol->vol_id);
216
217         if (*offp + count > vol->used_bytes)
218                 count_save = count = vol->used_bytes - *offp;
219
220         tbuf_size = vol->usable_leb_size;
221         if (count < tbuf_size)
222                 tbuf_size = ALIGN(count, ubi->min_io_size);
223         tbuf = vmalloc(tbuf_size);
224         if (!tbuf)
225                 return -ENOMEM;
226
227         len = count > tbuf_size ? tbuf_size : count;
228
229         tmp = *offp;
230         off = do_div(tmp, vol->usable_leb_size);
231         lnum = tmp;
232
233         do {
234                 cond_resched();
235
236                 if (off + len >= vol->usable_leb_size)
237                         len = vol->usable_leb_size - off;
238
239                 err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
240                 if (err)
241                         break;
242
243                 off += len;
244                 if (off == vol->usable_leb_size) {
245                         lnum += 1;
246                         off -= vol->usable_leb_size;
247                 }
248
249                 count -= len;
250                 *offp += len;
251
252                 err = copy_to_user(buf, tbuf, len);
253                 if (err) {
254                         err = -EFAULT;
255                         break;
256                 }
257
258                 buf += len;
259                 len = count > tbuf_size ? tbuf_size : count;
260         } while (count);
261
262         vfree(tbuf);
263         return err ? err : count_save - count;
264 }
265
266 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
267
268 /*
269  * This function allows to directly write to dynamic UBI volumes, without
270  * issuing the volume update operation. Available only as a debugging feature.
271  * Very useful for testing UBI.
272  */
273 static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
274                                      size_t count, loff_t *offp)
275 {
276         struct ubi_volume_desc *desc = file->private_data;
277         struct ubi_volume *vol = desc->vol;
278         struct ubi_device *ubi = vol->ubi;
279         int lnum, off, len, tbuf_size, err = 0;
280         size_t count_save = count;
281         char *tbuf;
282         uint64_t tmp;
283
284         dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
285                 count, *offp, vol->vol_id);
286
287         if (vol->vol_type == UBI_STATIC_VOLUME)
288                 return -EROFS;
289
290         tmp = *offp;
291         off = do_div(tmp, vol->usable_leb_size);
292         lnum = tmp;
293
294         if (off & (ubi->min_io_size - 1)) {
295                 dbg_err("unaligned position");
296                 return -EINVAL;
297         }
298
299         if (*offp + count > vol->used_bytes)
300                 count_save = count = vol->used_bytes - *offp;
301
302         /* We can write only in fractions of the minimum I/O unit */
303         if (count & (ubi->min_io_size - 1)) {
304                 dbg_err("unaligned write length");
305                 return -EINVAL;
306         }
307
308         tbuf_size = vol->usable_leb_size;
309         if (count < tbuf_size)
310                 tbuf_size = ALIGN(count, ubi->min_io_size);
311         tbuf = vmalloc(tbuf_size);
312         if (!tbuf)
313                 return -ENOMEM;
314
315         len = count > tbuf_size ? tbuf_size : count;
316
317         while (count) {
318                 cond_resched();
319
320                 if (off + len >= vol->usable_leb_size)
321                         len = vol->usable_leb_size - off;
322
323                 err = copy_from_user(tbuf, buf, len);
324                 if (err) {
325                         err = -EFAULT;
326                         break;
327                 }
328
329                 err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len,
330                                         UBI_UNKNOWN);
331                 if (err)
332                         break;
333
334                 off += len;
335                 if (off == vol->usable_leb_size) {
336                         lnum += 1;
337                         off -= vol->usable_leb_size;
338                 }
339
340                 count -= len;
341                 *offp += len;
342                 buf += len;
343                 len = count > tbuf_size ? tbuf_size : count;
344         }
345
346         vfree(tbuf);
347         return err ? err : count_save - count;
348 }
349
350 #else
351 #define vol_cdev_direct_write(file, buf, count, offp) (-EPERM)
352 #endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */
353
354 static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
355                               size_t count, loff_t *offp)
356 {
357         int err = 0;
358         struct ubi_volume_desc *desc = file->private_data;
359         struct ubi_volume *vol = desc->vol;
360         struct ubi_device *ubi = vol->ubi;
361
362         if (!vol->updating && !vol->changing_leb)
363                 return vol_cdev_direct_write(file, buf, count, offp);
364
365         if (vol->updating)
366                 err = ubi_more_update_data(ubi, vol, buf, count);
367         else
368                 err = ubi_more_leb_change_data(ubi, vol, buf, count);
369
370         if (err < 0) {
371                 ubi_err("cannot accept more %zd bytes of data, error %d",
372                         count, err);
373                 return err;
374         }
375
376         if (err) {
377                 /*
378                  * The operation is finished, @err contains number of actually
379                  * written bytes.
380                  */
381                 count = err;
382
383                 if (vol->changing_leb) {
384                         revoke_exclusive(desc, UBI_READWRITE);
385                         return count;
386                 }
387
388                 err = ubi_check_volume(ubi, vol->vol_id);
389                 if (err < 0)
390                         return err;
391
392                 if (err) {
393                         ubi_warn("volume %d on UBI device %d is corrupted",
394                                  vol->vol_id, ubi->ubi_num);
395                         vol->corrupted = 1;
396                 }
397                 vol->checked = 1;
398                 ubi_gluebi_updated(vol);
399                 revoke_exclusive(desc, UBI_READWRITE);
400         }
401
402         return count;
403 }
404
405 static int vol_cdev_ioctl(struct inode *inode, struct file *file,
406                           unsigned int cmd, unsigned long arg)
407 {
408         int err = 0;
409         struct ubi_volume_desc *desc = file->private_data;
410         struct ubi_volume *vol = desc->vol;
411         struct ubi_device *ubi = vol->ubi;
412         void __user *argp = (void __user *)arg;
413
414         switch (cmd) {
415         /* Volume update command */
416         case UBI_IOCVOLUP:
417         {
418                 int64_t bytes, rsvd_bytes;
419
420                 if (!capable(CAP_SYS_RESOURCE)) {
421                         err = -EPERM;
422                         break;
423                 }
424
425                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
426                 if (err) {
427                         err = -EFAULT;
428                         break;
429                 }
430
431                 if (desc->mode == UBI_READONLY) {
432                         err = -EROFS;
433                         break;
434                 }
435
436                 rsvd_bytes = (long long)vol->reserved_pebs *
437                                         ubi->leb_size-vol->data_pad;
438                 if (bytes < 0 || bytes > rsvd_bytes) {
439                         err = -EINVAL;
440                         break;
441                 }
442
443                 err = get_exclusive(desc);
444                 if (err < 0)
445                         break;
446
447                 err = ubi_start_update(ubi, vol, bytes);
448                 if (bytes == 0)
449                         revoke_exclusive(desc, UBI_READWRITE);
450                 break;
451         }
452
453         /* Atomic logical eraseblock change command */
454         case UBI_IOCEBCH:
455         {
456                 struct ubi_leb_change_req req;
457
458                 err = copy_from_user(&req, argp,
459                                      sizeof(struct ubi_leb_change_req));
460                 if (err) {
461                         err = -EFAULT;
462                         break;
463                 }
464
465                 if (desc->mode == UBI_READONLY ||
466                     vol->vol_type == UBI_STATIC_VOLUME) {
467                         err = -EROFS;
468                         break;
469                 }
470
471                 /* Validate the request */
472                 err = -EINVAL;
473                 if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
474                     req.bytes < 0 || req.lnum >= vol->usable_leb_size)
475                         break;
476                 if (req.dtype != UBI_LONGTERM && req.dtype != UBI_SHORTTERM &&
477                     req.dtype != UBI_UNKNOWN)
478                         break;
479
480                 err = get_exclusive(desc);
481                 if (err < 0)
482                         break;
483
484                 err = ubi_start_leb_change(ubi, vol, &req);
485                 if (req.bytes == 0)
486                         revoke_exclusive(desc, UBI_READWRITE);
487                 break;
488         }
489
490 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
491         /* Logical eraseblock erasure command */
492         case UBI_IOCEBER:
493         {
494                 int32_t lnum;
495
496                 err = get_user(lnum, (__user int32_t *)argp);
497                 if (err) {
498                         err = -EFAULT;
499                         break;
500                 }
501
502                 if (desc->mode == UBI_READONLY ||
503                     vol->vol_type == UBI_STATIC_VOLUME) {
504                         err = -EROFS;
505                         break;
506                 }
507
508                 if (lnum < 0 || lnum >= vol->reserved_pebs) {
509                         err = -EINVAL;
510                         break;
511                 }
512
513                 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
514                 err = ubi_eba_unmap_leb(ubi, vol, lnum);
515                 if (err)
516                         break;
517
518                 err = ubi_wl_flush(ubi);
519                 break;
520         }
521
522         /* Logical eraseblock map command */
523         case UBI_IOCEBMAP:
524         {
525                 struct ubi_map_req req;
526
527                 err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
528                 if (err) {
529                         err = -EFAULT;
530                         break;
531                 }
532                 err = ubi_leb_map(desc, req.lnum, req.dtype);
533                 break;
534         }
535 #endif
536
537         default:
538                 err = -ENOTTY;
539                 break;
540         }
541
542         return err;
543 }
544
545 /**
546  * verify_mkvol_req - verify volume creation request.
547  * @ubi: UBI device description object
548  * @req: the request to check
549  *
550  * This function zero if the request is correct, and %-EINVAL if not.
551  */
552 static int verify_mkvol_req(const struct ubi_device *ubi,
553                             const struct ubi_mkvol_req *req)
554 {
555         int n, err = -EINVAL;
556
557         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
558             req->name_len < 0)
559                 goto bad;
560
561         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
562             req->vol_id != UBI_VOL_NUM_AUTO)
563                 goto bad;
564
565         if (req->alignment == 0)
566                 goto bad;
567
568         if (req->bytes == 0)
569                 goto bad;
570
571         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
572             req->vol_type != UBI_STATIC_VOLUME)
573                 goto bad;
574
575         if (req->alignment > ubi->leb_size)
576                 goto bad;
577
578         n = req->alignment & (ubi->min_io_size - 1);
579         if (req->alignment != 1 && n)
580                 goto bad;
581
582         if (req->name_len > UBI_VOL_NAME_MAX) {
583                 err = -ENAMETOOLONG;
584                 goto bad;
585         }
586
587         n = strnlen(req->name, req->name_len + 1);
588         if (n != req->name_len)
589                 goto bad;
590
591         return 0;
592
593 bad:
594         dbg_err("bad volume creation request");
595         ubi_dbg_dump_mkvol_req(req);
596         return err;
597 }
598
599 /**
600  * verify_rsvol_req - verify volume re-size request.
601  * @ubi: UBI device description object
602  * @req: the request to check
603  *
604  * This function returns zero if the request is correct, and %-EINVAL if not.
605  */
606 static int verify_rsvol_req(const struct ubi_device *ubi,
607                             const struct ubi_rsvol_req *req)
608 {
609         if (req->bytes <= 0)
610                 return -EINVAL;
611
612         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
613                 return -EINVAL;
614
615         return 0;
616 }
617
618 /**
619  * rename_volumes - rename UBI volumes.
620  * @ubi: UBI device description object
621  * @req: volumes re-name request
622  *
623  * This is a helper function for the volume re-name IOCTL which validates the
624  * the request, opens the volume and calls corresponding volumes management
625  * function. Returns zero in case of success and a negative error code in case
626  * of failure.
627  */
628 static int rename_volumes(struct ubi_device *ubi,
629                           struct ubi_rnvol_req *req)
630 {
631         int i, n, err;
632         struct list_head rename_list;
633         struct ubi_rename_entry *re, *re1;
634
635         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
636                 return -EINVAL;
637
638         if (req->count == 0)
639                 return 0;
640
641         /* Validate volume IDs and names in the request */
642         for (i = 0; i < req->count; i++) {
643                 if (req->ents[i].vol_id < 0 ||
644                     req->ents[i].vol_id >= ubi->vtbl_slots)
645                         return -EINVAL;
646                 if (req->ents[i].name_len < 0)
647                         return -EINVAL;
648                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
649                         return -ENAMETOOLONG;
650                 req->ents[i].name[req->ents[i].name_len] = '\0';
651                 n = strlen(req->ents[i].name);
652                 if (n != req->ents[i].name_len)
653                         err = -EINVAL;
654         }
655
656         /* Make sure volume IDs and names are unique */
657         for (i = 0; i < req->count - 1; i++) {
658                 for (n = i + 1; n < req->count; n++) {
659                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
660                                 dbg_err("duplicated volume id %d",
661                                         req->ents[i].vol_id);
662                                 return -EINVAL;
663                         }
664                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
665                                 dbg_err("duplicated volume name \"%s\"",
666                                         req->ents[i].name);
667                                 return -EINVAL;
668                         }
669                 }
670         }
671
672         /* Create the re-name list */
673         INIT_LIST_HEAD(&rename_list);
674         for (i = 0; i < req->count; i++) {
675                 int vol_id = req->ents[i].vol_id;
676                 int name_len = req->ents[i].name_len;
677                 const char *name = req->ents[i].name;
678
679                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
680                 if (!re) {
681                         err = -ENOMEM;
682                         goto out_free;
683                 }
684
685                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
686                 if (IS_ERR(re->desc)) {
687                         err = PTR_ERR(re->desc);
688                         dbg_err("cannot open volume %d, error %d", vol_id, err);
689                         kfree(re);
690                         goto out_free;
691                 }
692
693                 /* Skip this re-naming if the name does not really change */
694                 if (re->desc->vol->name_len == name_len &&
695                     !memcmp(re->desc->vol->name, name, name_len)) {
696                         ubi_close_volume(re->desc);
697                         kfree(re);
698                         continue;
699                 }
700
701                 re->new_name_len = name_len;
702                 memcpy(re->new_name, name, name_len);
703                 list_add_tail(&re->list, &rename_list);
704                 dbg_msg("will rename volume %d from \"%s\" to \"%s\"",
705                         vol_id, re->desc->vol->name, name);
706         }
707
708         if (list_empty(&rename_list))
709                 return 0;
710
711         /* Find out the volumes which have to be removed */
712         list_for_each_entry(re, &rename_list, list) {
713                 struct ubi_volume_desc *desc;
714                 int no_remove_needed = 0;
715
716                 /*
717                  * Volume @re->vol_id is going to be re-named to
718                  * @re->new_name, while its current name is @name. If a volume
719                  * with name @re->new_name currently exists, it has to be
720                  * removed, unless it is also re-named in the request (@req).
721                  */
722                 list_for_each_entry(re1, &rename_list, list) {
723                         if (re->new_name_len == re1->desc->vol->name_len &&
724                             !memcmp(re->new_name, re1->desc->vol->name,
725                                     re1->desc->vol->name_len)) {
726                                 no_remove_needed = 1;
727                                 break;
728                         }
729                 }
730
731                 if (no_remove_needed)
732                         continue;
733
734                 /*
735                  * It seems we need to remove volume with name @re->new_name,
736                  * if it exists.
737                  */
738                 desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
739                                           UBI_EXCLUSIVE);
740                 if (IS_ERR(desc)) {
741                         err = PTR_ERR(desc);
742                         if (err == -ENODEV)
743                                 /* Re-naming into a non-existing volume name */
744                                 continue;
745
746                         /* The volume exists but busy, or an error occurred */
747                         dbg_err("cannot open volume \"%s\", error %d",
748                                 re->new_name, err);
749                         goto out_free;
750                 }
751
752                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
753                 if (!re) {
754                         err = -ENOMEM;
755                         ubi_close_volume(desc);
756                         goto out_free;
757                 }
758
759                 re->remove = 1;
760                 re->desc = desc;
761                 list_add(&re->list, &rename_list);
762                 dbg_msg("will remove volume %d, name \"%s\"",
763                         re->desc->vol->vol_id, re->desc->vol->name);
764         }
765
766         mutex_lock(&ubi->volumes_mutex);
767         err = ubi_rename_volumes(ubi, &rename_list);
768         mutex_unlock(&ubi->volumes_mutex);
769
770 out_free:
771         list_for_each_entry_safe(re, re1, &rename_list, list) {
772                 ubi_close_volume(re->desc);
773                 list_del(&re->list);
774                 kfree(re);
775         }
776         return err;
777 }
778
779 static int ubi_cdev_ioctl(struct inode *inode, struct file *file,
780                           unsigned int cmd, unsigned long arg)
781 {
782         int err = 0;
783         struct ubi_device *ubi;
784         struct ubi_volume_desc *desc;
785         void __user *argp = (void __user *)arg;
786
787         if (!capable(CAP_SYS_RESOURCE))
788                 return -EPERM;
789
790         ubi = ubi_get_by_major(imajor(inode));
791         if (!ubi)
792                 return -ENODEV;
793
794         switch (cmd) {
795         /* Create volume command */
796         case UBI_IOCMKVOL:
797         {
798                 struct ubi_mkvol_req req;
799
800                 dbg_gen("create volume");
801                 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
802                 if (err) {
803                         err = -EFAULT;
804                         break;
805                 }
806
807                 req.name[req.name_len] = '\0';
808                 err = verify_mkvol_req(ubi, &req);
809                 if (err)
810                         break;
811
812                 mutex_lock(&ubi->volumes_mutex);
813                 err = ubi_create_volume(ubi, &req);
814                 mutex_unlock(&ubi->volumes_mutex);
815                 if (err)
816                         break;
817
818                 err = put_user(req.vol_id, (__user int32_t *)argp);
819                 if (err)
820                         err = -EFAULT;
821
822                 break;
823         }
824
825         /* Remove volume command */
826         case UBI_IOCRMVOL:
827         {
828                 int vol_id;
829
830                 dbg_gen("remove volume");
831                 err = get_user(vol_id, (__user int32_t *)argp);
832                 if (err) {
833                         err = -EFAULT;
834                         break;
835                 }
836
837                 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
838                 if (IS_ERR(desc)) {
839                         err = PTR_ERR(desc);
840                         break;
841                 }
842
843                 mutex_lock(&ubi->volumes_mutex);
844                 err = ubi_remove_volume(desc, 0);
845                 mutex_unlock(&ubi->volumes_mutex);
846
847                 /*
848                  * The volume is deleted (unless an error occurred), and the
849                  * 'struct ubi_volume' object will be freed when
850                  * 'ubi_close_volume()' will call 'put_device()'.
851                  */
852                 ubi_close_volume(desc);
853                 break;
854         }
855
856         /* Re-size volume command */
857         case UBI_IOCRSVOL:
858         {
859                 int pebs;
860                 uint64_t tmp;
861                 struct ubi_rsvol_req req;
862
863                 dbg_gen("re-size volume");
864                 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
865                 if (err) {
866                         err = -EFAULT;
867                         break;
868                 }
869
870                 err = verify_rsvol_req(ubi, &req);
871                 if (err)
872                         break;
873
874                 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
875                 if (IS_ERR(desc)) {
876                         err = PTR_ERR(desc);
877                         break;
878                 }
879
880                 tmp = req.bytes;
881                 pebs = !!do_div(tmp, desc->vol->usable_leb_size);
882                 pebs += tmp;
883
884                 mutex_lock(&ubi->volumes_mutex);
885                 err = ubi_resize_volume(desc, pebs);
886                 mutex_unlock(&ubi->volumes_mutex);
887                 ubi_close_volume(desc);
888                 break;
889         }
890
891         /* Re-name volumes command */
892         case UBI_IOCRNVOL:
893         {
894                 struct ubi_rnvol_req *req;
895
896                 dbg_msg("re-name volumes");
897                 req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
898                 if (!req) {
899                         err = -ENOMEM;
900                         break;
901                 };
902
903                 err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
904                 if (err) {
905                         err = -EFAULT;
906                         kfree(req);
907                         break;
908                 }
909
910                 mutex_lock(&ubi->mult_mutex);
911                 err = rename_volumes(ubi, req);
912                 mutex_unlock(&ubi->mult_mutex);
913                 kfree(req);
914                 break;
915         }
916
917         default:
918                 err = -ENOTTY;
919                 break;
920         }
921
922         ubi_put_device(ubi);
923         return err;
924 }
925
926 static int ctrl_cdev_ioctl(struct inode *inode, struct file *file,
927                            unsigned int cmd, unsigned long arg)
928 {
929         int err = 0;
930         void __user *argp = (void __user *)arg;
931
932         if (!capable(CAP_SYS_RESOURCE))
933                 return -EPERM;
934
935         switch (cmd) {
936         /* Attach an MTD device command */
937         case UBI_IOCATT:
938         {
939                 struct ubi_attach_req req;
940                 struct mtd_info *mtd;
941
942                 dbg_gen("attach MTD device");
943                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
944                 if (err) {
945                         err = -EFAULT;
946                         break;
947                 }
948
949                 if (req.mtd_num < 0 ||
950                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
951                         err = -EINVAL;
952                         break;
953                 }
954
955                 mtd = get_mtd_device(NULL, req.mtd_num);
956                 if (IS_ERR(mtd)) {
957                         err = PTR_ERR(mtd);
958                         break;
959                 }
960
961                 /*
962                  * Note, further request verification is done by
963                  * 'ubi_attach_mtd_dev()'.
964                  */
965                 mutex_lock(&ubi_devices_mutex);
966                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
967                 mutex_unlock(&ubi_devices_mutex);
968                 if (err < 0)
969                         put_mtd_device(mtd);
970                 else
971                         /* @err contains UBI device number */
972                         err = put_user(err, (__user int32_t *)argp);
973
974                 break;
975         }
976
977         /* Detach an MTD device command */
978         case UBI_IOCDET:
979         {
980                 int ubi_num;
981
982                 dbg_gen("dettach MTD device");
983                 err = get_user(ubi_num, (__user int32_t *)argp);
984                 if (err) {
985                         err = -EFAULT;
986                         break;
987                 }
988
989                 mutex_lock(&ubi_devices_mutex);
990                 err = ubi_detach_mtd_dev(ubi_num, 0);
991                 mutex_unlock(&ubi_devices_mutex);
992                 break;
993         }
994
995         default:
996                 err = -ENOTTY;
997                 break;
998         }
999
1000         return err;
1001 }
1002
1003 /* UBI control character device operations */
1004 struct file_operations ubi_ctrl_cdev_operations = {
1005         .ioctl = ctrl_cdev_ioctl,
1006         .owner = THIS_MODULE,
1007 };
1008
1009 /* UBI character device operations */
1010 struct file_operations ubi_cdev_operations = {
1011         .owner = THIS_MODULE,
1012         .ioctl = ubi_cdev_ioctl,
1013         .llseek = no_llseek,
1014 };
1015
1016 /* UBI volume character device operations */
1017 struct file_operations ubi_vol_cdev_operations = {
1018         .owner   = THIS_MODULE,
1019         .open    = vol_cdev_open,
1020         .release = vol_cdev_release,
1021         .llseek  = vol_cdev_llseek,
1022         .read    = vol_cdev_read,
1023         .write   = vol_cdev_write,
1024         .ioctl   = vol_cdev_ioctl,
1025 };