UBI: fix checkpatch.pl warnings
[linux-2.6.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 #endif
522
523         default:
524                 err = -ENOTTY;
525                 break;
526         }
527
528         return err;
529 }
530
531 /**
532  * verify_mkvol_req - verify volume creation request.
533  * @ubi: UBI device description object
534  * @req: the request to check
535  *
536  * This function zero if the request is correct, and %-EINVAL if not.
537  */
538 static int verify_mkvol_req(const struct ubi_device *ubi,
539                             const struct ubi_mkvol_req *req)
540 {
541         int n, err = -EINVAL;
542
543         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
544             req->name_len < 0)
545                 goto bad;
546
547         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
548             req->vol_id != UBI_VOL_NUM_AUTO)
549                 goto bad;
550
551         if (req->alignment == 0)
552                 goto bad;
553
554         if (req->bytes == 0)
555                 goto bad;
556
557         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
558             req->vol_type != UBI_STATIC_VOLUME)
559                 goto bad;
560
561         if (req->alignment > ubi->leb_size)
562                 goto bad;
563
564         n = req->alignment & (ubi->min_io_size - 1);
565         if (req->alignment != 1 && n)
566                 goto bad;
567
568         if (req->name_len > UBI_VOL_NAME_MAX) {
569                 err = -ENAMETOOLONG;
570                 goto bad;
571         }
572
573         n = strnlen(req->name, req->name_len + 1);
574         if (n != req->name_len)
575                 goto bad;
576
577         return 0;
578
579 bad:
580         dbg_err("bad volume creation request");
581         ubi_dbg_dump_mkvol_req(req);
582         return err;
583 }
584
585 /**
586  * verify_rsvol_req - verify volume re-size request.
587  * @ubi: UBI device description object
588  * @req: the request to check
589  *
590  * This function returns zero if the request is correct, and %-EINVAL if not.
591  */
592 static int verify_rsvol_req(const struct ubi_device *ubi,
593                             const struct ubi_rsvol_req *req)
594 {
595         if (req->bytes <= 0)
596                 return -EINVAL;
597
598         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
599                 return -EINVAL;
600
601         return 0;
602 }
603
604 /**
605  * rename_volumes - rename UBI volumes.
606  * @ubi: UBI device description object
607  * @req: volumes re-name request
608  *
609  * This is a helper function for the volume re-name IOCTL which validates the
610  * the request, opens the volume and calls corresponding volumes management
611  * function. Returns zero in case of success and a negative error code in case
612  * of failure.
613  */
614 static int rename_volumes(struct ubi_device *ubi,
615                           struct ubi_rnvol_req *req)
616 {
617         int i, n, err;
618         struct list_head rename_list;
619         struct ubi_rename_entry *re, *re1;
620
621         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
622                 return -EINVAL;
623
624         if (req->count == 0)
625                 return 0;
626
627         /* Validate volume IDs and names in the request */
628         for (i = 0; i < req->count; i++) {
629                 if (req->ents[i].vol_id < 0 ||
630                     req->ents[i].vol_id >= ubi->vtbl_slots)
631                         return -EINVAL;
632                 if (req->ents[i].name_len < 0)
633                         return -EINVAL;
634                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
635                         return -ENAMETOOLONG;
636                 req->ents[i].name[req->ents[i].name_len] = '\0';
637                 n = strlen(req->ents[i].name);
638                 if (n != req->ents[i].name_len)
639                         err = -EINVAL;
640         }
641
642         /* Make sure volume IDs and names are unique */
643         for (i = 0; i < req->count - 1; i++) {
644                 for (n = i + 1; n < req->count; n++) {
645                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
646                                 dbg_err("duplicated volume id %d",
647                                         req->ents[i].vol_id);
648                                 return -EINVAL;
649                         }
650                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
651                                 dbg_err("duplicated volume name \"%s\"",
652                                         req->ents[i].name);
653                                 return -EINVAL;
654                         }
655                 }
656         }
657
658         /* Create the re-name list */
659         INIT_LIST_HEAD(&rename_list);
660         for (i = 0; i < req->count; i++) {
661                 int vol_id = req->ents[i].vol_id;
662                 int name_len = req->ents[i].name_len;
663                 const char *name = req->ents[i].name;
664
665                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
666                 if (!re) {
667                         err = -ENOMEM;
668                         goto out_free;
669                 }
670
671                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
672                 if (IS_ERR(re->desc)) {
673                         err = PTR_ERR(re->desc);
674                         dbg_err("cannot open volume %d, error %d", vol_id, err);
675                         kfree(re);
676                         goto out_free;
677                 }
678
679                 /* Skip this re-naming if the name does not really change */
680                 if (re->desc->vol->name_len == name_len &&
681                     !memcmp(re->desc->vol->name, name, name_len)) {
682                         ubi_close_volume(re->desc);
683                         kfree(re);
684                         continue;
685                 }
686
687                 re->new_name_len = name_len;
688                 memcpy(re->new_name, name, name_len);
689                 list_add_tail(&re->list, &rename_list);
690                 dbg_msg("will rename volume %d from \"%s\" to \"%s\"",
691                         vol_id, re->desc->vol->name, name);
692         }
693
694         if (list_empty(&rename_list))
695                 return 0;
696
697         /* Find out the volumes which have to be removed */
698         list_for_each_entry(re, &rename_list, list) {
699                 struct ubi_volume_desc *desc;
700                 int no_remove_needed = 0;
701
702                 /*
703                  * Volume @re->vol_id is going to be re-named to
704                  * @re->new_name, while its current name is @name. If a volume
705                  * with name @re->new_name currently exists, it has to be
706                  * removed, unless it is also re-named in the request (@req).
707                  */
708                 list_for_each_entry(re1, &rename_list, list) {
709                         if (re->new_name_len == re1->desc->vol->name_len &&
710                             !memcmp(re->new_name, re1->desc->vol->name,
711                                     re1->desc->vol->name_len)) {
712                                 no_remove_needed = 1;
713                                 break;
714                         }
715                 }
716
717                 if (no_remove_needed)
718                         continue;
719
720                 /*
721                  * It seems we need to remove volume with name @re->new_name,
722                  * if it exists.
723                  */
724                 desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
725                                           UBI_EXCLUSIVE);
726                 if (IS_ERR(desc)) {
727                         err = PTR_ERR(desc);
728                         if (err == -ENODEV)
729                                 /* Re-naming into a non-existing volume name */
730                                 continue;
731
732                         /* The volume exists but busy, or an error occurred */
733                         dbg_err("cannot open volume \"%s\", error %d",
734                                 re->new_name, err);
735                         goto out_free;
736                 }
737
738                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
739                 if (!re) {
740                         err = -ENOMEM;
741                         ubi_close_volume(desc);
742                         goto out_free;
743                 }
744
745                 re->remove = 1;
746                 re->desc = desc;
747                 list_add(&re->list, &rename_list);
748                 dbg_msg("will remove volume %d, name \"%s\"",
749                         re->desc->vol->vol_id, re->desc->vol->name);
750         }
751
752         mutex_lock(&ubi->volumes_mutex);
753         err = ubi_rename_volumes(ubi, &rename_list);
754         mutex_unlock(&ubi->volumes_mutex);
755
756 out_free:
757         list_for_each_entry_safe(re, re1, &rename_list, list) {
758                 ubi_close_volume(re->desc);
759                 list_del(&re->list);
760                 kfree(re);
761         }
762         return err;
763 }
764
765 static int ubi_cdev_ioctl(struct inode *inode, struct file *file,
766                           unsigned int cmd, unsigned long arg)
767 {
768         int err = 0;
769         struct ubi_device *ubi;
770         struct ubi_volume_desc *desc;
771         void __user *argp = (void __user *)arg;
772
773         if (!capable(CAP_SYS_RESOURCE))
774                 return -EPERM;
775
776         ubi = ubi_get_by_major(imajor(inode));
777         if (!ubi)
778                 return -ENODEV;
779
780         switch (cmd) {
781         /* Create volume command */
782         case UBI_IOCMKVOL:
783         {
784                 struct ubi_mkvol_req req;
785
786                 dbg_gen("create volume");
787                 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
788                 if (err) {
789                         err = -EFAULT;
790                         break;
791                 }
792
793                 req.name[req.name_len] = '\0';
794                 err = verify_mkvol_req(ubi, &req);
795                 if (err)
796                         break;
797
798                 mutex_lock(&ubi->volumes_mutex);
799                 err = ubi_create_volume(ubi, &req);
800                 mutex_unlock(&ubi->volumes_mutex);
801                 if (err)
802                         break;
803
804                 err = put_user(req.vol_id, (__user int32_t *)argp);
805                 if (err)
806                         err = -EFAULT;
807
808                 break;
809         }
810
811         /* Remove volume command */
812         case UBI_IOCRMVOL:
813         {
814                 int vol_id;
815
816                 dbg_gen("remove volume");
817                 err = get_user(vol_id, (__user int32_t *)argp);
818                 if (err) {
819                         err = -EFAULT;
820                         break;
821                 }
822
823                 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
824                 if (IS_ERR(desc)) {
825                         err = PTR_ERR(desc);
826                         break;
827                 }
828
829                 mutex_lock(&ubi->volumes_mutex);
830                 err = ubi_remove_volume(desc, 0);
831                 mutex_unlock(&ubi->volumes_mutex);
832
833                 /*
834                  * The volume is deleted (unless an error occurred), and the
835                  * 'struct ubi_volume' object will be freed when
836                  * 'ubi_close_volume()' will call 'put_device()'.
837                  */
838                 ubi_close_volume(desc);
839                 break;
840         }
841
842         /* Re-size volume command */
843         case UBI_IOCRSVOL:
844         {
845                 int pebs;
846                 uint64_t tmp;
847                 struct ubi_rsvol_req req;
848
849                 dbg_gen("re-size volume");
850                 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
851                 if (err) {
852                         err = -EFAULT;
853                         break;
854                 }
855
856                 err = verify_rsvol_req(ubi, &req);
857                 if (err)
858                         break;
859
860                 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
861                 if (IS_ERR(desc)) {
862                         err = PTR_ERR(desc);
863                         break;
864                 }
865
866                 tmp = req.bytes;
867                 pebs = !!do_div(tmp, desc->vol->usable_leb_size);
868                 pebs += tmp;
869
870                 mutex_lock(&ubi->volumes_mutex);
871                 err = ubi_resize_volume(desc, pebs);
872                 mutex_unlock(&ubi->volumes_mutex);
873                 ubi_close_volume(desc);
874                 break;
875         }
876
877         /* Re-name volumes command */
878         case UBI_IOCRNVOL:
879         {
880                 struct ubi_rnvol_req *req;
881
882                 dbg_msg("re-name volumes");
883                 req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
884                 if (!req) {
885                         err = -ENOMEM;
886                         break;
887                 };
888
889                 err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
890                 if (err) {
891                         err = -EFAULT;
892                         kfree(req);
893                         break;
894                 }
895
896                 mutex_lock(&ubi->mult_mutex);
897                 err = rename_volumes(ubi, req);
898                 mutex_unlock(&ubi->mult_mutex);
899                 kfree(req);
900                 break;
901         }
902
903         default:
904                 err = -ENOTTY;
905                 break;
906         }
907
908         ubi_put_device(ubi);
909         return err;
910 }
911
912 static int ctrl_cdev_ioctl(struct inode *inode, struct file *file,
913                            unsigned int cmd, unsigned long arg)
914 {
915         int err = 0;
916         void __user *argp = (void __user *)arg;
917
918         if (!capable(CAP_SYS_RESOURCE))
919                 return -EPERM;
920
921         switch (cmd) {
922         /* Attach an MTD device command */
923         case UBI_IOCATT:
924         {
925                 struct ubi_attach_req req;
926                 struct mtd_info *mtd;
927
928                 dbg_gen("attach MTD device");
929                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
930                 if (err) {
931                         err = -EFAULT;
932                         break;
933                 }
934
935                 if (req.mtd_num < 0 ||
936                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
937                         err = -EINVAL;
938                         break;
939                 }
940
941                 mtd = get_mtd_device(NULL, req.mtd_num);
942                 if (IS_ERR(mtd)) {
943                         err = PTR_ERR(mtd);
944                         break;
945                 }
946
947                 /*
948                  * Note, further request verification is done by
949                  * 'ubi_attach_mtd_dev()'.
950                  */
951                 mutex_lock(&ubi_devices_mutex);
952                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
953                 mutex_unlock(&ubi_devices_mutex);
954                 if (err < 0)
955                         put_mtd_device(mtd);
956                 else
957                         /* @err contains UBI device number */
958                         err = put_user(err, (__user int32_t *)argp);
959
960                 break;
961         }
962
963         /* Detach an MTD device command */
964         case UBI_IOCDET:
965         {
966                 int ubi_num;
967
968                 dbg_gen("dettach MTD device");
969                 err = get_user(ubi_num, (__user int32_t *)argp);
970                 if (err) {
971                         err = -EFAULT;
972                         break;
973                 }
974
975                 mutex_lock(&ubi_devices_mutex);
976                 err = ubi_detach_mtd_dev(ubi_num, 0);
977                 mutex_unlock(&ubi_devices_mutex);
978                 break;
979         }
980
981         default:
982                 err = -ENOTTY;
983                 break;
984         }
985
986         return err;
987 }
988
989 /* UBI control character device operations */
990 struct file_operations ubi_ctrl_cdev_operations = {
991         .ioctl = ctrl_cdev_ioctl,
992         .owner = THIS_MODULE,
993 };
994
995 /* UBI character device operations */
996 struct file_operations ubi_cdev_operations = {
997         .owner = THIS_MODULE,
998         .ioctl = ubi_cdev_ioctl,
999         .llseek = no_llseek,
1000 };
1001
1002 /* UBI volume character device operations */
1003 struct file_operations ubi_vol_cdev_operations = {
1004         .owner   = THIS_MODULE,
1005         .open    = vol_cdev_open,
1006         .release = vol_cdev_release,
1007         .llseek  = vol_cdev_llseek,
1008         .read    = vol_cdev_read,
1009         .write   = vol_cdev_write,
1010         .ioctl   = vol_cdev_ioctl,
1011 };