Merge branch 'sh/for-2.6.29' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal...
[linux-2.6] / 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/compat.h>
44 #include <linux/math64.h>
45 #include <mtd/ubi-user.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
199         dbg_gen("read %zd bytes from offset %lld of volume %d",
200                 count, *offp, vol->vol_id);
201
202         if (vol->updating) {
203                 dbg_err("updating");
204                 return -EBUSY;
205         }
206         if (vol->upd_marker) {
207                 dbg_err("damaged volume, update marker is set");
208                 return -EBADF;
209         }
210         if (*offp == vol->used_bytes || count == 0)
211                 return 0;
212
213         if (vol->corrupted)
214                 dbg_gen("read from corrupted volume %d", vol->vol_id);
215
216         if (*offp + count > vol->used_bytes)
217                 count_save = count = vol->used_bytes - *offp;
218
219         tbuf_size = vol->usable_leb_size;
220         if (count < tbuf_size)
221                 tbuf_size = ALIGN(count, ubi->min_io_size);
222         tbuf = vmalloc(tbuf_size);
223         if (!tbuf)
224                 return -ENOMEM;
225
226         len = count > tbuf_size ? tbuf_size : count;
227         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
228
229         do {
230                 cond_resched();
231
232                 if (off + len >= vol->usable_leb_size)
233                         len = vol->usable_leb_size - off;
234
235                 err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
236                 if (err)
237                         break;
238
239                 off += len;
240                 if (off == vol->usable_leb_size) {
241                         lnum += 1;
242                         off -= vol->usable_leb_size;
243                 }
244
245                 count -= len;
246                 *offp += len;
247
248                 err = copy_to_user(buf, tbuf, len);
249                 if (err) {
250                         err = -EFAULT;
251                         break;
252                 }
253
254                 buf += len;
255                 len = count > tbuf_size ? tbuf_size : count;
256         } while (count);
257
258         vfree(tbuf);
259         return err ? err : count_save - count;
260 }
261
262 /*
263  * This function allows to directly write to dynamic UBI volumes, without
264  * issuing the volume update operation.
265  */
266 static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
267                                      size_t count, loff_t *offp)
268 {
269         struct ubi_volume_desc *desc = file->private_data;
270         struct ubi_volume *vol = desc->vol;
271         struct ubi_device *ubi = vol->ubi;
272         int lnum, off, len, tbuf_size, err = 0;
273         size_t count_save = count;
274         char *tbuf;
275
276         if (!vol->direct_writes)
277                 return -EPERM;
278
279         dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
280                 count, *offp, vol->vol_id);
281
282         if (vol->vol_type == UBI_STATIC_VOLUME)
283                 return -EROFS;
284
285         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
286         if (off & (ubi->min_io_size - 1)) {
287                 dbg_err("unaligned position");
288                 return -EINVAL;
289         }
290
291         if (*offp + count > vol->used_bytes)
292                 count_save = count = vol->used_bytes - *offp;
293
294         /* We can write only in fractions of the minimum I/O unit */
295         if (count & (ubi->min_io_size - 1)) {
296                 dbg_err("unaligned write length");
297                 return -EINVAL;
298         }
299
300         tbuf_size = vol->usable_leb_size;
301         if (count < tbuf_size)
302                 tbuf_size = ALIGN(count, ubi->min_io_size);
303         tbuf = vmalloc(tbuf_size);
304         if (!tbuf)
305                 return -ENOMEM;
306
307         len = count > tbuf_size ? tbuf_size : count;
308
309         while (count) {
310                 cond_resched();
311
312                 if (off + len >= vol->usable_leb_size)
313                         len = vol->usable_leb_size - off;
314
315                 err = copy_from_user(tbuf, buf, len);
316                 if (err) {
317                         err = -EFAULT;
318                         break;
319                 }
320
321                 err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len,
322                                         UBI_UNKNOWN);
323                 if (err)
324                         break;
325
326                 off += len;
327                 if (off == vol->usable_leb_size) {
328                         lnum += 1;
329                         off -= vol->usable_leb_size;
330                 }
331
332                 count -= len;
333                 *offp += len;
334                 buf += len;
335                 len = count > tbuf_size ? tbuf_size : count;
336         }
337
338         vfree(tbuf);
339         return err ? err : count_save - count;
340 }
341
342 static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
343                               size_t count, loff_t *offp)
344 {
345         int err = 0;
346         struct ubi_volume_desc *desc = file->private_data;
347         struct ubi_volume *vol = desc->vol;
348         struct ubi_device *ubi = vol->ubi;
349
350         if (!vol->updating && !vol->changing_leb)
351                 return vol_cdev_direct_write(file, buf, count, offp);
352
353         if (vol->updating)
354                 err = ubi_more_update_data(ubi, vol, buf, count);
355         else
356                 err = ubi_more_leb_change_data(ubi, vol, buf, count);
357
358         if (err < 0) {
359                 ubi_err("cannot accept more %zd bytes of data, error %d",
360                         count, err);
361                 return err;
362         }
363
364         if (err) {
365                 /*
366                  * The operation is finished, @err contains number of actually
367                  * written bytes.
368                  */
369                 count = err;
370
371                 if (vol->changing_leb) {
372                         revoke_exclusive(desc, UBI_READWRITE);
373                         return count;
374                 }
375
376                 err = ubi_check_volume(ubi, vol->vol_id);
377                 if (err < 0)
378                         return err;
379
380                 if (err) {
381                         ubi_warn("volume %d on UBI device %d is corrupted",
382                                  vol->vol_id, ubi->ubi_num);
383                         vol->corrupted = 1;
384                 }
385                 vol->checked = 1;
386                 ubi_gluebi_updated(vol);
387                 revoke_exclusive(desc, UBI_READWRITE);
388         }
389
390         return count;
391 }
392
393 static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
394                            unsigned long arg)
395 {
396         int err = 0;
397         struct ubi_volume_desc *desc = file->private_data;
398         struct ubi_volume *vol = desc->vol;
399         struct ubi_device *ubi = vol->ubi;
400         void __user *argp = (void __user *)arg;
401
402         switch (cmd) {
403         /* Volume update command */
404         case UBI_IOCVOLUP:
405         {
406                 int64_t bytes, rsvd_bytes;
407
408                 if (!capable(CAP_SYS_RESOURCE)) {
409                         err = -EPERM;
410                         break;
411                 }
412
413                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
414                 if (err) {
415                         err = -EFAULT;
416                         break;
417                 }
418
419                 if (desc->mode == UBI_READONLY) {
420                         err = -EROFS;
421                         break;
422                 }
423
424                 rsvd_bytes = (long long)vol->reserved_pebs *
425                                         ubi->leb_size-vol->data_pad;
426                 if (bytes < 0 || bytes > rsvd_bytes) {
427                         err = -EINVAL;
428                         break;
429                 }
430
431                 err = get_exclusive(desc);
432                 if (err < 0)
433                         break;
434
435                 err = ubi_start_update(ubi, vol, bytes);
436                 if (bytes == 0)
437                         revoke_exclusive(desc, UBI_READWRITE);
438                 break;
439         }
440
441         /* Atomic logical eraseblock change command */
442         case UBI_IOCEBCH:
443         {
444                 struct ubi_leb_change_req req;
445
446                 err = copy_from_user(&req, argp,
447                                      sizeof(struct ubi_leb_change_req));
448                 if (err) {
449                         err = -EFAULT;
450                         break;
451                 }
452
453                 if (desc->mode == UBI_READONLY ||
454                     vol->vol_type == UBI_STATIC_VOLUME) {
455                         err = -EROFS;
456                         break;
457                 }
458
459                 /* Validate the request */
460                 err = -EINVAL;
461                 if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
462                     req.bytes < 0 || req.lnum >= vol->usable_leb_size)
463                         break;
464                 if (req.dtype != UBI_LONGTERM && req.dtype != UBI_SHORTTERM &&
465                     req.dtype != UBI_UNKNOWN)
466                         break;
467
468                 err = get_exclusive(desc);
469                 if (err < 0)
470                         break;
471
472                 err = ubi_start_leb_change(ubi, vol, &req);
473                 if (req.bytes == 0)
474                         revoke_exclusive(desc, UBI_READWRITE);
475                 break;
476         }
477
478         /* Logical eraseblock erasure command */
479         case UBI_IOCEBER:
480         {
481                 int32_t lnum;
482
483                 err = get_user(lnum, (__user int32_t *)argp);
484                 if (err) {
485                         err = -EFAULT;
486                         break;
487                 }
488
489                 if (desc->mode == UBI_READONLY ||
490                     vol->vol_type == UBI_STATIC_VOLUME) {
491                         err = -EROFS;
492                         break;
493                 }
494
495                 if (lnum < 0 || lnum >= vol->reserved_pebs) {
496                         err = -EINVAL;
497                         break;
498                 }
499
500                 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
501                 err = ubi_eba_unmap_leb(ubi, vol, lnum);
502                 if (err)
503                         break;
504
505                 err = ubi_wl_flush(ubi);
506                 break;
507         }
508
509         /* Logical eraseblock map command */
510         case UBI_IOCEBMAP:
511         {
512                 struct ubi_map_req req;
513
514                 err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
515                 if (err) {
516                         err = -EFAULT;
517                         break;
518                 }
519                 err = ubi_leb_map(desc, req.lnum, req.dtype);
520                 break;
521         }
522
523         /* Logical eraseblock un-map command */
524         case UBI_IOCEBUNMAP:
525         {
526                 int32_t lnum;
527
528                 err = get_user(lnum, (__user int32_t *)argp);
529                 if (err) {
530                         err = -EFAULT;
531                         break;
532                 }
533                 err = ubi_leb_unmap(desc, lnum);
534                 break;
535         }
536
537         /* Check if logical eraseblock is mapped command */
538         case UBI_IOCEBISMAP:
539         {
540                 int32_t lnum;
541
542                 err = get_user(lnum, (__user int32_t *)argp);
543                 if (err) {
544                         err = -EFAULT;
545                         break;
546                 }
547                 err = ubi_is_mapped(desc, lnum);
548                 break;
549         }
550
551         /* Set volume property command*/
552         case UBI_IOCSETPROP:
553         {
554                 struct ubi_set_prop_req req;
555
556                 err = copy_from_user(&req, argp,
557                                 sizeof(struct ubi_set_prop_req));
558                 if (err) {
559                         err = -EFAULT;
560                         break;
561                 }
562                 switch (req.property) {
563                 case UBI_PROP_DIRECT_WRITE:
564                         mutex_lock(&ubi->volumes_mutex);
565                         desc->vol->direct_writes = !!req.value;
566                         mutex_unlock(&ubi->volumes_mutex);
567                         break;
568                 default:
569                         err = -EINVAL;
570                         break;
571                 }
572                 break;
573         }
574
575         default:
576                 err = -ENOTTY;
577                 break;
578         }
579         return err;
580 }
581
582 /**
583  * verify_mkvol_req - verify volume creation request.
584  * @ubi: UBI device description object
585  * @req: the request to check
586  *
587  * This function zero if the request is correct, and %-EINVAL if not.
588  */
589 static int verify_mkvol_req(const struct ubi_device *ubi,
590                             const struct ubi_mkvol_req *req)
591 {
592         int n, err = -EINVAL;
593
594         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
595             req->name_len < 0)
596                 goto bad;
597
598         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
599             req->vol_id != UBI_VOL_NUM_AUTO)
600                 goto bad;
601
602         if (req->alignment == 0)
603                 goto bad;
604
605         if (req->bytes == 0)
606                 goto bad;
607
608         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
609             req->vol_type != UBI_STATIC_VOLUME)
610                 goto bad;
611
612         if (req->alignment > ubi->leb_size)
613                 goto bad;
614
615         n = req->alignment & (ubi->min_io_size - 1);
616         if (req->alignment != 1 && n)
617                 goto bad;
618
619         if (req->name_len > UBI_VOL_NAME_MAX) {
620                 err = -ENAMETOOLONG;
621                 goto bad;
622         }
623
624         n = strnlen(req->name, req->name_len + 1);
625         if (n != req->name_len)
626                 goto bad;
627
628         return 0;
629
630 bad:
631         dbg_err("bad volume creation request");
632         ubi_dbg_dump_mkvol_req(req);
633         return err;
634 }
635
636 /**
637  * verify_rsvol_req - verify volume re-size request.
638  * @ubi: UBI device description object
639  * @req: the request to check
640  *
641  * This function returns zero if the request is correct, and %-EINVAL if not.
642  */
643 static int verify_rsvol_req(const struct ubi_device *ubi,
644                             const struct ubi_rsvol_req *req)
645 {
646         if (req->bytes <= 0)
647                 return -EINVAL;
648
649         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
650                 return -EINVAL;
651
652         return 0;
653 }
654
655 /**
656  * rename_volumes - rename UBI volumes.
657  * @ubi: UBI device description object
658  * @req: volumes re-name request
659  *
660  * This is a helper function for the volume re-name IOCTL which validates the
661  * the request, opens the volume and calls corresponding volumes management
662  * function. Returns zero in case of success and a negative error code in case
663  * of failure.
664  */
665 static int rename_volumes(struct ubi_device *ubi,
666                           struct ubi_rnvol_req *req)
667 {
668         int i, n, err;
669         struct list_head rename_list;
670         struct ubi_rename_entry *re, *re1;
671
672         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
673                 return -EINVAL;
674
675         if (req->count == 0)
676                 return 0;
677
678         /* Validate volume IDs and names in the request */
679         for (i = 0; i < req->count; i++) {
680                 if (req->ents[i].vol_id < 0 ||
681                     req->ents[i].vol_id >= ubi->vtbl_slots)
682                         return -EINVAL;
683                 if (req->ents[i].name_len < 0)
684                         return -EINVAL;
685                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
686                         return -ENAMETOOLONG;
687                 req->ents[i].name[req->ents[i].name_len] = '\0';
688                 n = strlen(req->ents[i].name);
689                 if (n != req->ents[i].name_len)
690                         err = -EINVAL;
691         }
692
693         /* Make sure volume IDs and names are unique */
694         for (i = 0; i < req->count - 1; i++) {
695                 for (n = i + 1; n < req->count; n++) {
696                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
697                                 dbg_err("duplicated volume id %d",
698                                         req->ents[i].vol_id);
699                                 return -EINVAL;
700                         }
701                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
702                                 dbg_err("duplicated volume name \"%s\"",
703                                         req->ents[i].name);
704                                 return -EINVAL;
705                         }
706                 }
707         }
708
709         /* Create the re-name list */
710         INIT_LIST_HEAD(&rename_list);
711         for (i = 0; i < req->count; i++) {
712                 int vol_id = req->ents[i].vol_id;
713                 int name_len = req->ents[i].name_len;
714                 const char *name = req->ents[i].name;
715
716                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
717                 if (!re) {
718                         err = -ENOMEM;
719                         goto out_free;
720                 }
721
722                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
723                 if (IS_ERR(re->desc)) {
724                         err = PTR_ERR(re->desc);
725                         dbg_err("cannot open volume %d, error %d", vol_id, err);
726                         kfree(re);
727                         goto out_free;
728                 }
729
730                 /* Skip this re-naming if the name does not really change */
731                 if (re->desc->vol->name_len == name_len &&
732                     !memcmp(re->desc->vol->name, name, name_len)) {
733                         ubi_close_volume(re->desc);
734                         kfree(re);
735                         continue;
736                 }
737
738                 re->new_name_len = name_len;
739                 memcpy(re->new_name, name, name_len);
740                 list_add_tail(&re->list, &rename_list);
741                 dbg_msg("will rename volume %d from \"%s\" to \"%s\"",
742                         vol_id, re->desc->vol->name, name);
743         }
744
745         if (list_empty(&rename_list))
746                 return 0;
747
748         /* Find out the volumes which have to be removed */
749         list_for_each_entry(re, &rename_list, list) {
750                 struct ubi_volume_desc *desc;
751                 int no_remove_needed = 0;
752
753                 /*
754                  * Volume @re->vol_id is going to be re-named to
755                  * @re->new_name, while its current name is @name. If a volume
756                  * with name @re->new_name currently exists, it has to be
757                  * removed, unless it is also re-named in the request (@req).
758                  */
759                 list_for_each_entry(re1, &rename_list, list) {
760                         if (re->new_name_len == re1->desc->vol->name_len &&
761                             !memcmp(re->new_name, re1->desc->vol->name,
762                                     re1->desc->vol->name_len)) {
763                                 no_remove_needed = 1;
764                                 break;
765                         }
766                 }
767
768                 if (no_remove_needed)
769                         continue;
770
771                 /*
772                  * It seems we need to remove volume with name @re->new_name,
773                  * if it exists.
774                  */
775                 desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
776                                           UBI_EXCLUSIVE);
777                 if (IS_ERR(desc)) {
778                         err = PTR_ERR(desc);
779                         if (err == -ENODEV)
780                                 /* Re-naming into a non-existing volume name */
781                                 continue;
782
783                         /* The volume exists but busy, or an error occurred */
784                         dbg_err("cannot open volume \"%s\", error %d",
785                                 re->new_name, err);
786                         goto out_free;
787                 }
788
789                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
790                 if (!re) {
791                         err = -ENOMEM;
792                         ubi_close_volume(desc);
793                         goto out_free;
794                 }
795
796                 re->remove = 1;
797                 re->desc = desc;
798                 list_add(&re->list, &rename_list);
799                 dbg_msg("will remove volume %d, name \"%s\"",
800                         re->desc->vol->vol_id, re->desc->vol->name);
801         }
802
803         mutex_lock(&ubi->volumes_mutex);
804         err = ubi_rename_volumes(ubi, &rename_list);
805         mutex_unlock(&ubi->volumes_mutex);
806
807 out_free:
808         list_for_each_entry_safe(re, re1, &rename_list, list) {
809                 ubi_close_volume(re->desc);
810                 list_del(&re->list);
811                 kfree(re);
812         }
813         return err;
814 }
815
816 static long ubi_cdev_ioctl(struct file *file, unsigned int cmd,
817                            unsigned long arg)
818 {
819         int err = 0;
820         struct ubi_device *ubi;
821         struct ubi_volume_desc *desc;
822         void __user *argp = (void __user *)arg;
823
824         if (!capable(CAP_SYS_RESOURCE))
825                 return -EPERM;
826
827         ubi = ubi_get_by_major(imajor(file->f_mapping->host));
828         if (!ubi)
829                 return -ENODEV;
830
831         switch (cmd) {
832         /* Create volume command */
833         case UBI_IOCMKVOL:
834         {
835                 struct ubi_mkvol_req req;
836
837                 dbg_gen("create volume");
838                 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
839                 if (err) {
840                         err = -EFAULT;
841                         break;
842                 }
843
844                 req.name[req.name_len] = '\0';
845                 err = verify_mkvol_req(ubi, &req);
846                 if (err)
847                         break;
848
849                 mutex_lock(&ubi->volumes_mutex);
850                 err = ubi_create_volume(ubi, &req);
851                 mutex_unlock(&ubi->volumes_mutex);
852                 if (err)
853                         break;
854
855                 err = put_user(req.vol_id, (__user int32_t *)argp);
856                 if (err)
857                         err = -EFAULT;
858
859                 break;
860         }
861
862         /* Remove volume command */
863         case UBI_IOCRMVOL:
864         {
865                 int vol_id;
866
867                 dbg_gen("remove volume");
868                 err = get_user(vol_id, (__user int32_t *)argp);
869                 if (err) {
870                         err = -EFAULT;
871                         break;
872                 }
873
874                 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
875                 if (IS_ERR(desc)) {
876                         err = PTR_ERR(desc);
877                         break;
878                 }
879
880                 mutex_lock(&ubi->volumes_mutex);
881                 err = ubi_remove_volume(desc, 0);
882                 mutex_unlock(&ubi->volumes_mutex);
883
884                 /*
885                  * The volume is deleted (unless an error occurred), and the
886                  * 'struct ubi_volume' object will be freed when
887                  * 'ubi_close_volume()' will call 'put_device()'.
888                  */
889                 ubi_close_volume(desc);
890                 break;
891         }
892
893         /* Re-size volume command */
894         case UBI_IOCRSVOL:
895         {
896                 int pebs;
897                 struct ubi_rsvol_req req;
898
899                 dbg_gen("re-size volume");
900                 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
901                 if (err) {
902                         err = -EFAULT;
903                         break;
904                 }
905
906                 err = verify_rsvol_req(ubi, &req);
907                 if (err)
908                         break;
909
910                 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
911                 if (IS_ERR(desc)) {
912                         err = PTR_ERR(desc);
913                         break;
914                 }
915
916                 pebs = div_u64(req.bytes + desc->vol->usable_leb_size - 1,
917                                desc->vol->usable_leb_size);
918
919                 mutex_lock(&ubi->volumes_mutex);
920                 err = ubi_resize_volume(desc, pebs);
921                 mutex_unlock(&ubi->volumes_mutex);
922                 ubi_close_volume(desc);
923                 break;
924         }
925
926         /* Re-name volumes command */
927         case UBI_IOCRNVOL:
928         {
929                 struct ubi_rnvol_req *req;
930
931                 dbg_msg("re-name volumes");
932                 req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
933                 if (!req) {
934                         err = -ENOMEM;
935                         break;
936                 };
937
938                 err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
939                 if (err) {
940                         err = -EFAULT;
941                         kfree(req);
942                         break;
943                 }
944
945                 mutex_lock(&ubi->mult_mutex);
946                 err = rename_volumes(ubi, req);
947                 mutex_unlock(&ubi->mult_mutex);
948                 kfree(req);
949                 break;
950         }
951
952         default:
953                 err = -ENOTTY;
954                 break;
955         }
956
957         ubi_put_device(ubi);
958         return err;
959 }
960
961 static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd,
962                             unsigned long arg)
963 {
964         int err = 0;
965         void __user *argp = (void __user *)arg;
966
967         if (!capable(CAP_SYS_RESOURCE))
968                 return -EPERM;
969
970         switch (cmd) {
971         /* Attach an MTD device command */
972         case UBI_IOCATT:
973         {
974                 struct ubi_attach_req req;
975                 struct mtd_info *mtd;
976
977                 dbg_gen("attach MTD device");
978                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
979                 if (err) {
980                         err = -EFAULT;
981                         break;
982                 }
983
984                 if (req.mtd_num < 0 ||
985                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
986                         err = -EINVAL;
987                         break;
988                 }
989
990                 mtd = get_mtd_device(NULL, req.mtd_num);
991                 if (IS_ERR(mtd)) {
992                         err = PTR_ERR(mtd);
993                         break;
994                 }
995
996                 /*
997                  * Note, further request verification is done by
998                  * 'ubi_attach_mtd_dev()'.
999                  */
1000                 mutex_lock(&ubi_devices_mutex);
1001                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
1002                 mutex_unlock(&ubi_devices_mutex);
1003                 if (err < 0)
1004                         put_mtd_device(mtd);
1005                 else
1006                         /* @err contains UBI device number */
1007                         err = put_user(err, (__user int32_t *)argp);
1008
1009                 break;
1010         }
1011
1012         /* Detach an MTD device command */
1013         case UBI_IOCDET:
1014         {
1015                 int ubi_num;
1016
1017                 dbg_gen("dettach MTD device");
1018                 err = get_user(ubi_num, (__user int32_t *)argp);
1019                 if (err) {
1020                         err = -EFAULT;
1021                         break;
1022                 }
1023
1024                 mutex_lock(&ubi_devices_mutex);
1025                 err = ubi_detach_mtd_dev(ubi_num, 0);
1026                 mutex_unlock(&ubi_devices_mutex);
1027                 break;
1028         }
1029
1030         default:
1031                 err = -ENOTTY;
1032                 break;
1033         }
1034
1035         return err;
1036 }
1037
1038 #ifdef CONFIG_COMPAT
1039 static long vol_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1040                                   unsigned long arg)
1041 {
1042         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1043
1044         return vol_cdev_ioctl(file, cmd, translated_arg);
1045 }
1046
1047 static long ubi_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1048                                   unsigned long arg)
1049 {
1050         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1051
1052         return ubi_cdev_ioctl(file, cmd, translated_arg);
1053 }
1054
1055 static long ctrl_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1056                                    unsigned long arg)
1057 {
1058         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1059
1060         return ctrl_cdev_ioctl(file, cmd, translated_arg);
1061 }
1062 #else
1063 #define vol_cdev_compat_ioctl  NULL
1064 #define ubi_cdev_compat_ioctl  NULL
1065 #define ctrl_cdev_compat_ioctl NULL
1066 #endif
1067
1068 /* UBI volume character device operations */
1069 const struct file_operations ubi_vol_cdev_operations = {
1070         .owner          = THIS_MODULE,
1071         .open           = vol_cdev_open,
1072         .release        = vol_cdev_release,
1073         .llseek         = vol_cdev_llseek,
1074         .read           = vol_cdev_read,
1075         .write          = vol_cdev_write,
1076         .unlocked_ioctl = vol_cdev_ioctl,
1077         .compat_ioctl   = vol_cdev_compat_ioctl,
1078 };
1079
1080 /* UBI character device operations */
1081 const struct file_operations ubi_cdev_operations = {
1082         .owner          = THIS_MODULE,
1083         .llseek         = no_llseek,
1084         .unlocked_ioctl = ubi_cdev_ioctl,
1085         .compat_ioctl   = ubi_cdev_compat_ioctl,
1086 };
1087
1088 /* UBI control character device operations */
1089 const struct file_operations ubi_ctrl_cdev_operations = {
1090         .owner          = THIS_MODULE,
1091         .unlocked_ioctl = ctrl_cdev_ioctl,
1092         .compat_ioctl   = ctrl_cdev_compat_ioctl,
1093 };