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UBI: fix nameless volumes handling
[~shefty/rdma-dev.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/slab.h>
41 #include <linux/ioctl.h>
42 #include <linux/capability.h>
43 #include <linux/uaccess.h>
44 #include <linux/compat.h>
45 #include <linux/math64.h>
46 #include <mtd/ubi-user.h>
47 #include "ubi.h"
48
49 /**
50  * get_exclusive - get exclusive access to an UBI volume.
51  * @desc: volume descriptor
52  *
53  * This function changes UBI volume open mode to "exclusive". Returns previous
54  * mode value (positive integer) in case of success and a negative error code
55  * in case of failure.
56  */
57 static int get_exclusive(struct ubi_volume_desc *desc)
58 {
59         int users, err;
60         struct ubi_volume *vol = desc->vol;
61
62         spin_lock(&vol->ubi->volumes_lock);
63         users = vol->readers + vol->writers + vol->exclusive;
64         ubi_assert(users > 0);
65         if (users > 1) {
66                 dbg_err("%d users for volume %d", users, vol->vol_id);
67                 err = -EBUSY;
68         } else {
69                 vol->readers = vol->writers = 0;
70                 vol->exclusive = 1;
71                 err = desc->mode;
72                 desc->mode = UBI_EXCLUSIVE;
73         }
74         spin_unlock(&vol->ubi->volumes_lock);
75
76         return err;
77 }
78
79 /**
80  * revoke_exclusive - revoke exclusive mode.
81  * @desc: volume descriptor
82  * @mode: new mode to switch to
83  */
84 static void revoke_exclusive(struct ubi_volume_desc *desc, int mode)
85 {
86         struct ubi_volume *vol = desc->vol;
87
88         spin_lock(&vol->ubi->volumes_lock);
89         ubi_assert(vol->readers == 0 && vol->writers == 0);
90         ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE);
91         vol->exclusive = 0;
92         if (mode == UBI_READONLY)
93                 vol->readers = 1;
94         else if (mode == UBI_READWRITE)
95                 vol->writers = 1;
96         else
97                 vol->exclusive = 1;
98         spin_unlock(&vol->ubi->volumes_lock);
99
100         desc->mode = mode;
101 }
102
103 static int vol_cdev_open(struct inode *inode, struct file *file)
104 {
105         struct ubi_volume_desc *desc;
106         int vol_id = iminor(inode) - 1, mode, ubi_num;
107
108         ubi_num = ubi_major2num(imajor(inode));
109         if (ubi_num < 0)
110                 return ubi_num;
111
112         if (file->f_mode & FMODE_WRITE)
113                 mode = UBI_READWRITE;
114         else
115                 mode = UBI_READONLY;
116
117         dbg_gen("open device %d, volume %d, mode %d",
118                 ubi_num, vol_id, mode);
119
120         desc = ubi_open_volume(ubi_num, vol_id, mode);
121         if (IS_ERR(desc))
122                 return PTR_ERR(desc);
123
124         file->private_data = desc;
125         return 0;
126 }
127
128 static int vol_cdev_release(struct inode *inode, struct file *file)
129 {
130         struct ubi_volume_desc *desc = file->private_data;
131         struct ubi_volume *vol = desc->vol;
132
133         dbg_gen("release device %d, volume %d, mode %d",
134                 vol->ubi->ubi_num, vol->vol_id, desc->mode);
135
136         if (vol->updating) {
137                 ubi_warn("update of volume %d not finished, volume is damaged",
138                          vol->vol_id);
139                 ubi_assert(!vol->changing_leb);
140                 vol->updating = 0;
141                 vfree(vol->upd_buf);
142         } else if (vol->changing_leb) {
143                 dbg_gen("only %lld of %lld bytes received for atomic LEB change"
144                         " for volume %d:%d, cancel", vol->upd_received,
145                         vol->upd_bytes, vol->ubi->ubi_num, vol->vol_id);
146                 vol->changing_leb = 0;
147                 vfree(vol->upd_buf);
148         }
149
150         ubi_close_volume(desc);
151         return 0;
152 }
153
154 static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin)
155 {
156         struct ubi_volume_desc *desc = file->private_data;
157         struct ubi_volume *vol = desc->vol;
158         loff_t new_offset;
159
160         if (vol->updating) {
161                 /* Update is in progress, seeking is prohibited */
162                 dbg_err("updating");
163                 return -EBUSY;
164         }
165
166         switch (origin) {
167         case 0: /* SEEK_SET */
168                 new_offset = offset;
169                 break;
170         case 1: /* SEEK_CUR */
171                 new_offset = file->f_pos + offset;
172                 break;
173         case 2: /* SEEK_END */
174                 new_offset = vol->used_bytes + offset;
175                 break;
176         default:
177                 return -EINVAL;
178         }
179
180         if (new_offset < 0 || new_offset > vol->used_bytes) {
181                 dbg_err("bad seek %lld", new_offset);
182                 return -EINVAL;
183         }
184
185         dbg_gen("seek volume %d, offset %lld, origin %d, new offset %lld",
186                 vol->vol_id, offset, origin, new_offset);
187
188         file->f_pos = new_offset;
189         return new_offset;
190 }
191
192 static int vol_cdev_fsync(struct file *file, loff_t start, loff_t end, int datasync)
193 {
194         struct ubi_volume_desc *desc = file->private_data;
195         struct ubi_device *ubi = desc->vol->ubi;
196         struct inode *inode = file->f_path.dentry->d_inode;
197         int err;
198         mutex_lock(&inode->i_mutex);
199         err = ubi_sync(ubi->ubi_num);
200         mutex_unlock(&inode->i_mutex);
201         return err;
202 }
203
204
205 static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
206                              loff_t *offp)
207 {
208         struct ubi_volume_desc *desc = file->private_data;
209         struct ubi_volume *vol = desc->vol;
210         struct ubi_device *ubi = vol->ubi;
211         int err, lnum, off, len,  tbuf_size;
212         size_t count_save = count;
213         void *tbuf;
214
215         dbg_gen("read %zd bytes from offset %lld of volume %d",
216                 count, *offp, vol->vol_id);
217
218         if (vol->updating) {
219                 dbg_err("updating");
220                 return -EBUSY;
221         }
222         if (vol->upd_marker) {
223                 dbg_err("damaged volume, update marker is set");
224                 return -EBADF;
225         }
226         if (*offp == vol->used_bytes || count == 0)
227                 return 0;
228
229         if (vol->corrupted)
230                 dbg_gen("read from corrupted volume %d", vol->vol_id);
231
232         if (*offp + count > vol->used_bytes)
233                 count_save = count = vol->used_bytes - *offp;
234
235         tbuf_size = vol->usable_leb_size;
236         if (count < tbuf_size)
237                 tbuf_size = ALIGN(count, ubi->min_io_size);
238         tbuf = vmalloc(tbuf_size);
239         if (!tbuf)
240                 return -ENOMEM;
241
242         len = count > tbuf_size ? tbuf_size : count;
243         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
244
245         do {
246                 cond_resched();
247
248                 if (off + len >= vol->usable_leb_size)
249                         len = vol->usable_leb_size - off;
250
251                 err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
252                 if (err)
253                         break;
254
255                 off += len;
256                 if (off == vol->usable_leb_size) {
257                         lnum += 1;
258                         off -= vol->usable_leb_size;
259                 }
260
261                 count -= len;
262                 *offp += len;
263
264                 err = copy_to_user(buf, tbuf, len);
265                 if (err) {
266                         err = -EFAULT;
267                         break;
268                 }
269
270                 buf += len;
271                 len = count > tbuf_size ? tbuf_size : count;
272         } while (count);
273
274         vfree(tbuf);
275         return err ? err : count_save - count;
276 }
277
278 /*
279  * This function allows to directly write to dynamic UBI volumes, without
280  * issuing the volume update operation.
281  */
282 static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
283                                      size_t count, loff_t *offp)
284 {
285         struct ubi_volume_desc *desc = file->private_data;
286         struct ubi_volume *vol = desc->vol;
287         struct ubi_device *ubi = vol->ubi;
288         int lnum, off, len, tbuf_size, err = 0;
289         size_t count_save = count;
290         char *tbuf;
291
292         if (!vol->direct_writes)
293                 return -EPERM;
294
295         dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
296                 count, *offp, vol->vol_id);
297
298         if (vol->vol_type == UBI_STATIC_VOLUME)
299                 return -EROFS;
300
301         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
302         if (off & (ubi->min_io_size - 1)) {
303                 dbg_err("unaligned position");
304                 return -EINVAL;
305         }
306
307         if (*offp + count > vol->used_bytes)
308                 count_save = count = vol->used_bytes - *offp;
309
310         /* We can write only in fractions of the minimum I/O unit */
311         if (count & (ubi->min_io_size - 1)) {
312                 dbg_err("unaligned write length");
313                 return -EINVAL;
314         }
315
316         tbuf_size = vol->usable_leb_size;
317         if (count < tbuf_size)
318                 tbuf_size = ALIGN(count, ubi->min_io_size);
319         tbuf = vmalloc(tbuf_size);
320         if (!tbuf)
321                 return -ENOMEM;
322
323         len = count > tbuf_size ? tbuf_size : count;
324
325         while (count) {
326                 cond_resched();
327
328                 if (off + len >= vol->usable_leb_size)
329                         len = vol->usable_leb_size - off;
330
331                 err = copy_from_user(tbuf, buf, len);
332                 if (err) {
333                         err = -EFAULT;
334                         break;
335                 }
336
337                 err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len,
338                                         UBI_UNKNOWN);
339                 if (err)
340                         break;
341
342                 off += len;
343                 if (off == vol->usable_leb_size) {
344                         lnum += 1;
345                         off -= vol->usable_leb_size;
346                 }
347
348                 count -= len;
349                 *offp += len;
350                 buf += len;
351                 len = count > tbuf_size ? tbuf_size : count;
352         }
353
354         vfree(tbuf);
355         return err ? err : count_save - count;
356 }
357
358 static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
359                               size_t count, loff_t *offp)
360 {
361         int err = 0;
362         struct ubi_volume_desc *desc = file->private_data;
363         struct ubi_volume *vol = desc->vol;
364         struct ubi_device *ubi = vol->ubi;
365
366         if (!vol->updating && !vol->changing_leb)
367                 return vol_cdev_direct_write(file, buf, count, offp);
368
369         if (vol->updating)
370                 err = ubi_more_update_data(ubi, vol, buf, count);
371         else
372                 err = ubi_more_leb_change_data(ubi, vol, buf, count);
373
374         if (err < 0) {
375                 ubi_err("cannot accept more %zd bytes of data, error %d",
376                         count, err);
377                 return err;
378         }
379
380         if (err) {
381                 /*
382                  * The operation is finished, @err contains number of actually
383                  * written bytes.
384                  */
385                 count = err;
386
387                 if (vol->changing_leb) {
388                         revoke_exclusive(desc, UBI_READWRITE);
389                         return count;
390                 }
391
392                 err = ubi_check_volume(ubi, vol->vol_id);
393                 if (err < 0)
394                         return err;
395
396                 if (err) {
397                         ubi_warn("volume %d on UBI device %d is corrupted",
398                                  vol->vol_id, ubi->ubi_num);
399                         vol->corrupted = 1;
400                 }
401                 vol->checked = 1;
402                 ubi_volume_notify(ubi, vol, UBI_VOLUME_UPDATED);
403                 revoke_exclusive(desc, UBI_READWRITE);
404         }
405
406         return count;
407 }
408
409 static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
410                            unsigned long arg)
411 {
412         int err = 0;
413         struct ubi_volume_desc *desc = file->private_data;
414         struct ubi_volume *vol = desc->vol;
415         struct ubi_device *ubi = vol->ubi;
416         void __user *argp = (void __user *)arg;
417
418         switch (cmd) {
419         /* Volume update command */
420         case UBI_IOCVOLUP:
421         {
422                 int64_t bytes, rsvd_bytes;
423
424                 if (!capable(CAP_SYS_RESOURCE)) {
425                         err = -EPERM;
426                         break;
427                 }
428
429                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
430                 if (err) {
431                         err = -EFAULT;
432                         break;
433                 }
434
435                 if (desc->mode == UBI_READONLY) {
436                         err = -EROFS;
437                         break;
438                 }
439
440                 rsvd_bytes = (long long)vol->reserved_pebs *
441                                         ubi->leb_size-vol->data_pad;
442                 if (bytes < 0 || bytes > rsvd_bytes) {
443                         err = -EINVAL;
444                         break;
445                 }
446
447                 err = get_exclusive(desc);
448                 if (err < 0)
449                         break;
450
451                 err = ubi_start_update(ubi, vol, bytes);
452                 if (bytes == 0)
453                         revoke_exclusive(desc, UBI_READWRITE);
454                 break;
455         }
456
457         /* Atomic logical eraseblock change command */
458         case UBI_IOCEBCH:
459         {
460                 struct ubi_leb_change_req req;
461
462                 err = copy_from_user(&req, argp,
463                                      sizeof(struct ubi_leb_change_req));
464                 if (err) {
465                         err = -EFAULT;
466                         break;
467                 }
468
469                 if (desc->mode == UBI_READONLY ||
470                     vol->vol_type == UBI_STATIC_VOLUME) {
471                         err = -EROFS;
472                         break;
473                 }
474
475                 /* Validate the request */
476                 err = -EINVAL;
477                 if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
478                     req.bytes < 0 || req.lnum >= vol->usable_leb_size)
479                         break;
480                 if (req.dtype != UBI_LONGTERM && req.dtype != UBI_SHORTTERM &&
481                     req.dtype != UBI_UNKNOWN)
482                         break;
483
484                 err = get_exclusive(desc);
485                 if (err < 0)
486                         break;
487
488                 err = ubi_start_leb_change(ubi, vol, &req);
489                 if (req.bytes == 0)
490                         revoke_exclusive(desc, UBI_READWRITE);
491                 break;
492         }
493
494         /* Logical eraseblock erasure command */
495         case UBI_IOCEBER:
496         {
497                 int32_t lnum;
498
499                 err = get_user(lnum, (__user int32_t *)argp);
500                 if (err) {
501                         err = -EFAULT;
502                         break;
503                 }
504
505                 if (desc->mode == UBI_READONLY ||
506                     vol->vol_type == UBI_STATIC_VOLUME) {
507                         err = -EROFS;
508                         break;
509                 }
510
511                 if (lnum < 0 || lnum >= vol->reserved_pebs) {
512                         err = -EINVAL;
513                         break;
514                 }
515
516                 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
517                 err = ubi_eba_unmap_leb(ubi, vol, lnum);
518                 if (err)
519                         break;
520
521                 err = ubi_wl_flush(ubi);
522                 break;
523         }
524
525         /* Logical eraseblock map command */
526         case UBI_IOCEBMAP:
527         {
528                 struct ubi_map_req req;
529
530                 err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
531                 if (err) {
532                         err = -EFAULT;
533                         break;
534                 }
535                 err = ubi_leb_map(desc, req.lnum, req.dtype);
536                 break;
537         }
538
539         /* Logical eraseblock un-map command */
540         case UBI_IOCEBUNMAP:
541         {
542                 int32_t lnum;
543
544                 err = get_user(lnum, (__user int32_t *)argp);
545                 if (err) {
546                         err = -EFAULT;
547                         break;
548                 }
549                 err = ubi_leb_unmap(desc, lnum);
550                 break;
551         }
552
553         /* Check if logical eraseblock is mapped command */
554         case UBI_IOCEBISMAP:
555         {
556                 int32_t lnum;
557
558                 err = get_user(lnum, (__user int32_t *)argp);
559                 if (err) {
560                         err = -EFAULT;
561                         break;
562                 }
563                 err = ubi_is_mapped(desc, lnum);
564                 break;
565         }
566
567         /* Set volume property command */
568         case UBI_IOCSETVOLPROP:
569         {
570                 struct ubi_set_vol_prop_req req;
571
572                 err = copy_from_user(&req, argp,
573                                      sizeof(struct ubi_set_vol_prop_req));
574                 if (err) {
575                         err = -EFAULT;
576                         break;
577                 }
578                 switch (req.property) {
579                 case UBI_VOL_PROP_DIRECT_WRITE:
580                         mutex_lock(&ubi->device_mutex);
581                         desc->vol->direct_writes = !!req.value;
582                         mutex_unlock(&ubi->device_mutex);
583                         break;
584                 default:
585                         err = -EINVAL;
586                         break;
587                 }
588                 break;
589         }
590
591         default:
592                 err = -ENOTTY;
593                 break;
594         }
595         return err;
596 }
597
598 /**
599  * verify_mkvol_req - verify volume creation request.
600  * @ubi: UBI device description object
601  * @req: the request to check
602  *
603  * This function zero if the request is correct, and %-EINVAL if not.
604  */
605 static int verify_mkvol_req(const struct ubi_device *ubi,
606                             const struct ubi_mkvol_req *req)
607 {
608         int n, err = -EINVAL;
609
610         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
611             req->name_len < 0)
612                 goto bad;
613
614         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
615             req->vol_id != UBI_VOL_NUM_AUTO)
616                 goto bad;
617
618         if (req->alignment == 0)
619                 goto bad;
620
621         if (req->bytes == 0)
622                 goto bad;
623
624         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
625             req->vol_type != UBI_STATIC_VOLUME)
626                 goto bad;
627
628         if (req->alignment > ubi->leb_size)
629                 goto bad;
630
631         n = req->alignment & (ubi->min_io_size - 1);
632         if (req->alignment != 1 && n)
633                 goto bad;
634
635         if (!req->name[0] || !req->name_len)
636                 goto bad;
637
638         if (req->name_len > UBI_VOL_NAME_MAX) {
639                 err = -ENAMETOOLONG;
640                 goto bad;
641         }
642
643         n = strnlen(req->name, req->name_len + 1);
644         if (n != req->name_len)
645                 goto bad;
646
647         return 0;
648
649 bad:
650         dbg_err("bad volume creation request");
651         ubi_dbg_dump_mkvol_req(req);
652         return err;
653 }
654
655 /**
656  * verify_rsvol_req - verify volume re-size request.
657  * @ubi: UBI device description object
658  * @req: the request to check
659  *
660  * This function returns zero if the request is correct, and %-EINVAL if not.
661  */
662 static int verify_rsvol_req(const struct ubi_device *ubi,
663                             const struct ubi_rsvol_req *req)
664 {
665         if (req->bytes <= 0)
666                 return -EINVAL;
667
668         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
669                 return -EINVAL;
670
671         return 0;
672 }
673
674 /**
675  * rename_volumes - rename UBI volumes.
676  * @ubi: UBI device description object
677  * @req: volumes re-name request
678  *
679  * This is a helper function for the volume re-name IOCTL which validates the
680  * the request, opens the volume and calls corresponding volumes management
681  * function. Returns zero in case of success and a negative error code in case
682  * of failure.
683  */
684 static int rename_volumes(struct ubi_device *ubi,
685                           struct ubi_rnvol_req *req)
686 {
687         int i, n, err;
688         struct list_head rename_list;
689         struct ubi_rename_entry *re, *re1;
690
691         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
692                 return -EINVAL;
693
694         if (req->count == 0)
695                 return 0;
696
697         /* Validate volume IDs and names in the request */
698         for (i = 0; i < req->count; i++) {
699                 if (req->ents[i].vol_id < 0 ||
700                     req->ents[i].vol_id >= ubi->vtbl_slots)
701                         return -EINVAL;
702                 if (req->ents[i].name_len < 0)
703                         return -EINVAL;
704                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
705                         return -ENAMETOOLONG;
706                 req->ents[i].name[req->ents[i].name_len] = '\0';
707                 n = strlen(req->ents[i].name);
708                 if (n != req->ents[i].name_len)
709                         err = -EINVAL;
710         }
711
712         /* Make sure volume IDs and names are unique */
713         for (i = 0; i < req->count - 1; i++) {
714                 for (n = i + 1; n < req->count; n++) {
715                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
716                                 dbg_err("duplicated volume id %d",
717                                         req->ents[i].vol_id);
718                                 return -EINVAL;
719                         }
720                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
721                                 dbg_err("duplicated volume name \"%s\"",
722                                         req->ents[i].name);
723                                 return -EINVAL;
724                         }
725                 }
726         }
727
728         /* Create the re-name list */
729         INIT_LIST_HEAD(&rename_list);
730         for (i = 0; i < req->count; i++) {
731                 int vol_id = req->ents[i].vol_id;
732                 int name_len = req->ents[i].name_len;
733                 const char *name = req->ents[i].name;
734
735                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
736                 if (!re) {
737                         err = -ENOMEM;
738                         goto out_free;
739                 }
740
741                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
742                 if (IS_ERR(re->desc)) {
743                         err = PTR_ERR(re->desc);
744                         dbg_err("cannot open volume %d, error %d", vol_id, err);
745                         kfree(re);
746                         goto out_free;
747                 }
748
749                 /* Skip this re-naming if the name does not really change */
750                 if (re->desc->vol->name_len == name_len &&
751                     !memcmp(re->desc->vol->name, name, name_len)) {
752                         ubi_close_volume(re->desc);
753                         kfree(re);
754                         continue;
755                 }
756
757                 re->new_name_len = name_len;
758                 memcpy(re->new_name, name, name_len);
759                 list_add_tail(&re->list, &rename_list);
760                 dbg_msg("will rename volume %d from \"%s\" to \"%s\"",
761                         vol_id, re->desc->vol->name, name);
762         }
763
764         if (list_empty(&rename_list))
765                 return 0;
766
767         /* Find out the volumes which have to be removed */
768         list_for_each_entry(re, &rename_list, list) {
769                 struct ubi_volume_desc *desc;
770                 int no_remove_needed = 0;
771
772                 /*
773                  * Volume @re->vol_id is going to be re-named to
774                  * @re->new_name, while its current name is @name. If a volume
775                  * with name @re->new_name currently exists, it has to be
776                  * removed, unless it is also re-named in the request (@req).
777                  */
778                 list_for_each_entry(re1, &rename_list, list) {
779                         if (re->new_name_len == re1->desc->vol->name_len &&
780                             !memcmp(re->new_name, re1->desc->vol->name,
781                                     re1->desc->vol->name_len)) {
782                                 no_remove_needed = 1;
783                                 break;
784                         }
785                 }
786
787                 if (no_remove_needed)
788                         continue;
789
790                 /*
791                  * It seems we need to remove volume with name @re->new_name,
792                  * if it exists.
793                  */
794                 desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
795                                           UBI_EXCLUSIVE);
796                 if (IS_ERR(desc)) {
797                         err = PTR_ERR(desc);
798                         if (err == -ENODEV)
799                                 /* Re-naming into a non-existing volume name */
800                                 continue;
801
802                         /* The volume exists but busy, or an error occurred */
803                         dbg_err("cannot open volume \"%s\", error %d",
804                                 re->new_name, err);
805                         goto out_free;
806                 }
807
808                 re1 = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
809                 if (!re1) {
810                         err = -ENOMEM;
811                         ubi_close_volume(desc);
812                         goto out_free;
813                 }
814
815                 re1->remove = 1;
816                 re1->desc = desc;
817                 list_add(&re1->list, &rename_list);
818                 dbg_msg("will remove volume %d, name \"%s\"",
819                         re1->desc->vol->vol_id, re1->desc->vol->name);
820         }
821
822         mutex_lock(&ubi->device_mutex);
823         err = ubi_rename_volumes(ubi, &rename_list);
824         mutex_unlock(&ubi->device_mutex);
825
826 out_free:
827         list_for_each_entry_safe(re, re1, &rename_list, list) {
828                 ubi_close_volume(re->desc);
829                 list_del(&re->list);
830                 kfree(re);
831         }
832         return err;
833 }
834
835 static long ubi_cdev_ioctl(struct file *file, unsigned int cmd,
836                            unsigned long arg)
837 {
838         int err = 0;
839         struct ubi_device *ubi;
840         struct ubi_volume_desc *desc;
841         void __user *argp = (void __user *)arg;
842
843         if (!capable(CAP_SYS_RESOURCE))
844                 return -EPERM;
845
846         ubi = ubi_get_by_major(imajor(file->f_mapping->host));
847         if (!ubi)
848                 return -ENODEV;
849
850         switch (cmd) {
851         /* Create volume command */
852         case UBI_IOCMKVOL:
853         {
854                 struct ubi_mkvol_req req;
855
856                 dbg_gen("create volume");
857                 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
858                 if (err) {
859                         err = -EFAULT;
860                         break;
861                 }
862
863                 err = verify_mkvol_req(ubi, &req);
864                 if (err)
865                         break;
866
867                 mutex_lock(&ubi->device_mutex);
868                 err = ubi_create_volume(ubi, &req);
869                 mutex_unlock(&ubi->device_mutex);
870                 if (err)
871                         break;
872
873                 err = put_user(req.vol_id, (__user int32_t *)argp);
874                 if (err)
875                         err = -EFAULT;
876
877                 break;
878         }
879
880         /* Remove volume command */
881         case UBI_IOCRMVOL:
882         {
883                 int vol_id;
884
885                 dbg_gen("remove volume");
886                 err = get_user(vol_id, (__user int32_t *)argp);
887                 if (err) {
888                         err = -EFAULT;
889                         break;
890                 }
891
892                 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
893                 if (IS_ERR(desc)) {
894                         err = PTR_ERR(desc);
895                         break;
896                 }
897
898                 mutex_lock(&ubi->device_mutex);
899                 err = ubi_remove_volume(desc, 0);
900                 mutex_unlock(&ubi->device_mutex);
901
902                 /*
903                  * The volume is deleted (unless an error occurred), and the
904                  * 'struct ubi_volume' object will be freed when
905                  * 'ubi_close_volume()' will call 'put_device()'.
906                  */
907                 ubi_close_volume(desc);
908                 break;
909         }
910
911         /* Re-size volume command */
912         case UBI_IOCRSVOL:
913         {
914                 int pebs;
915                 struct ubi_rsvol_req req;
916
917                 dbg_gen("re-size volume");
918                 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
919                 if (err) {
920                         err = -EFAULT;
921                         break;
922                 }
923
924                 err = verify_rsvol_req(ubi, &req);
925                 if (err)
926                         break;
927
928                 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
929                 if (IS_ERR(desc)) {
930                         err = PTR_ERR(desc);
931                         break;
932                 }
933
934                 pebs = div_u64(req.bytes + desc->vol->usable_leb_size - 1,
935                                desc->vol->usable_leb_size);
936
937                 mutex_lock(&ubi->device_mutex);
938                 err = ubi_resize_volume(desc, pebs);
939                 mutex_unlock(&ubi->device_mutex);
940                 ubi_close_volume(desc);
941                 break;
942         }
943
944         /* Re-name volumes command */
945         case UBI_IOCRNVOL:
946         {
947                 struct ubi_rnvol_req *req;
948
949                 dbg_msg("re-name volumes");
950                 req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
951                 if (!req) {
952                         err = -ENOMEM;
953                         break;
954                 };
955
956                 err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
957                 if (err) {
958                         err = -EFAULT;
959                         kfree(req);
960                         break;
961                 }
962
963                 err = rename_volumes(ubi, req);
964                 kfree(req);
965                 break;
966         }
967
968         default:
969                 err = -ENOTTY;
970                 break;
971         }
972
973         ubi_put_device(ubi);
974         return err;
975 }
976
977 static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd,
978                             unsigned long arg)
979 {
980         int err = 0;
981         void __user *argp = (void __user *)arg;
982
983         if (!capable(CAP_SYS_RESOURCE))
984                 return -EPERM;
985
986         switch (cmd) {
987         /* Attach an MTD device command */
988         case UBI_IOCATT:
989         {
990                 struct ubi_attach_req req;
991                 struct mtd_info *mtd;
992
993                 dbg_gen("attach MTD device");
994                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
995                 if (err) {
996                         err = -EFAULT;
997                         break;
998                 }
999
1000                 if (req.mtd_num < 0 ||
1001                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
1002                         err = -EINVAL;
1003                         break;
1004                 }
1005
1006                 mtd = get_mtd_device(NULL, req.mtd_num);
1007                 if (IS_ERR(mtd)) {
1008                         err = PTR_ERR(mtd);
1009                         break;
1010                 }
1011
1012                 /*
1013                  * Note, further request verification is done by
1014                  * 'ubi_attach_mtd_dev()'.
1015                  */
1016                 mutex_lock(&ubi_devices_mutex);
1017                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
1018                 mutex_unlock(&ubi_devices_mutex);
1019                 if (err < 0)
1020                         put_mtd_device(mtd);
1021                 else
1022                         /* @err contains UBI device number */
1023                         err = put_user(err, (__user int32_t *)argp);
1024
1025                 break;
1026         }
1027
1028         /* Detach an MTD device command */
1029         case UBI_IOCDET:
1030         {
1031                 int ubi_num;
1032
1033                 dbg_gen("dettach MTD device");
1034                 err = get_user(ubi_num, (__user int32_t *)argp);
1035                 if (err) {
1036                         err = -EFAULT;
1037                         break;
1038                 }
1039
1040                 mutex_lock(&ubi_devices_mutex);
1041                 err = ubi_detach_mtd_dev(ubi_num, 0);
1042                 mutex_unlock(&ubi_devices_mutex);
1043                 break;
1044         }
1045
1046         default:
1047                 err = -ENOTTY;
1048                 break;
1049         }
1050
1051         return err;
1052 }
1053
1054 #ifdef CONFIG_COMPAT
1055 static long vol_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 vol_cdev_ioctl(file, cmd, translated_arg);
1061 }
1062
1063 static long ubi_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1064                                   unsigned long arg)
1065 {
1066         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1067
1068         return ubi_cdev_ioctl(file, cmd, translated_arg);
1069 }
1070
1071 static long ctrl_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1072                                    unsigned long arg)
1073 {
1074         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1075
1076         return ctrl_cdev_ioctl(file, cmd, translated_arg);
1077 }
1078 #else
1079 #define vol_cdev_compat_ioctl  NULL
1080 #define ubi_cdev_compat_ioctl  NULL
1081 #define ctrl_cdev_compat_ioctl NULL
1082 #endif
1083
1084 /* UBI volume character device operations */
1085 const struct file_operations ubi_vol_cdev_operations = {
1086         .owner          = THIS_MODULE,
1087         .open           = vol_cdev_open,
1088         .release        = vol_cdev_release,
1089         .llseek         = vol_cdev_llseek,
1090         .read           = vol_cdev_read,
1091         .write          = vol_cdev_write,
1092         .fsync          = vol_cdev_fsync,
1093         .unlocked_ioctl = vol_cdev_ioctl,
1094         .compat_ioctl   = vol_cdev_compat_ioctl,
1095 };
1096
1097 /* UBI character device operations */
1098 const struct file_operations ubi_cdev_operations = {
1099         .owner          = THIS_MODULE,
1100         .llseek         = no_llseek,
1101         .unlocked_ioctl = ubi_cdev_ioctl,
1102         .compat_ioctl   = ubi_cdev_compat_ioctl,
1103 };
1104
1105 /* UBI control character device operations */
1106 const struct file_operations ubi_ctrl_cdev_operations = {
1107         .owner          = THIS_MODULE,
1108         .unlocked_ioctl = ctrl_cdev_ioctl,
1109         .compat_ioctl   = ctrl_cdev_compat_ioctl,
1110         .llseek         = no_llseek,
1111 };