blob: fe4da1e96c52a67b1b79676ff281e1e4f6162b8b [file] [log] [blame]
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +04001/*
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
33#include <linux/module.h>
34#include <linux/stat.h>
35#include <linux/ioctl.h>
36#include <linux/capability.h>
37#include <mtd/ubi-user.h>
38#include <asm/uaccess.h>
39#include <asm/div64.h>
40#include "ubi.h"
41
42/*
43 * Maximum sequence numbers of UBI and volume character device IOCTLs (direct
44 * logical eraseblock erase is a debug-only feature).
45 */
46#define UBI_CDEV_IOC_MAX_SEQ 2
47#ifndef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
48#define VOL_CDEV_IOC_MAX_SEQ 1
49#else
50#define VOL_CDEV_IOC_MAX_SEQ 2
51#endif
52
53/**
54 * major_to_device - get UBI device object by character device major number.
55 * @major: major number
56 *
57 * This function returns a pointer to the UBI device object.
58 */
59static struct ubi_device *major_to_device(int major)
60{
61 int i;
62
63 for (i = 0; i < ubi_devices_cnt; i++)
64 if (ubi_devices[i] && ubi_devices[i]->major == major)
65 return ubi_devices[i];
66 BUG();
Paul Mundtadd0b432007-07-18 18:39:45 +090067 return NULL;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040068}
69
70/**
71 * get_exclusive - get exclusive access to an UBI volume.
72 * @desc: volume descriptor
73 *
74 * This function changes UBI volume open mode to "exclusive". Returns previous
75 * mode value (positive integer) in case of success and a negative error code
76 * in case of failure.
77 */
78static int get_exclusive(struct ubi_volume_desc *desc)
79{
80 int users, err;
81 struct ubi_volume *vol = desc->vol;
82
83 spin_lock(&vol->ubi->volumes_lock);
84 users = vol->readers + vol->writers + vol->exclusive;
85 ubi_assert(users > 0);
86 if (users > 1) {
87 dbg_err("%d users for volume %d", users, vol->vol_id);
88 err = -EBUSY;
89 } else {
90 vol->readers = vol->writers = 0;
91 vol->exclusive = 1;
92 err = desc->mode;
93 desc->mode = UBI_EXCLUSIVE;
94 }
95 spin_unlock(&vol->ubi->volumes_lock);
96
97 return err;
98}
99
100/**
101 * revoke_exclusive - revoke exclusive mode.
102 * @desc: volume descriptor
103 * @mode: new mode to switch to
104 */
105static void revoke_exclusive(struct ubi_volume_desc *desc, int mode)
106{
107 struct ubi_volume *vol = desc->vol;
108
109 spin_lock(&vol->ubi->volumes_lock);
110 ubi_assert(vol->readers == 0 && vol->writers == 0);
111 ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE);
112 vol->exclusive = 0;
113 if (mode == UBI_READONLY)
114 vol->readers = 1;
115 else if (mode == UBI_READWRITE)
116 vol->writers = 1;
117 else
118 vol->exclusive = 1;
119 spin_unlock(&vol->ubi->volumes_lock);
120
121 desc->mode = mode;
122}
123
124static int vol_cdev_open(struct inode *inode, struct file *file)
125{
126 struct ubi_volume_desc *desc;
127 const struct ubi_device *ubi = major_to_device(imajor(inode));
128 int vol_id = iminor(inode) - 1;
129 int mode;
130
131 if (file->f_mode & FMODE_WRITE)
132 mode = UBI_READWRITE;
133 else
134 mode = UBI_READONLY;
135
136 dbg_msg("open volume %d, mode %d", vol_id, mode);
137
138 desc = ubi_open_volume(ubi->ubi_num, vol_id, mode);
139 if (IS_ERR(desc))
140 return PTR_ERR(desc);
141
142 file->private_data = desc;
143 return 0;
144}
145
146static int vol_cdev_release(struct inode *inode, struct file *file)
147{
148 struct ubi_volume_desc *desc = file->private_data;
149 struct ubi_volume *vol = desc->vol;
150
151 dbg_msg("release volume %d, mode %d", vol->vol_id, desc->mode);
152
153 if (vol->updating) {
154 ubi_warn("update of volume %d not finished, volume is damaged",
155 vol->vol_id);
156 vol->updating = 0;
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300157 vfree(vol->upd_buf);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400158 }
159
160 ubi_close_volume(desc);
161 return 0;
162}
163
164static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin)
165{
166 struct ubi_volume_desc *desc = file->private_data;
167 struct ubi_volume *vol = desc->vol;
168 loff_t new_offset;
169
170 if (vol->updating) {
171 /* Update is in progress, seeking is prohibited */
172 dbg_err("updating");
173 return -EBUSY;
174 }
175
176 switch (origin) {
177 case 0: /* SEEK_SET */
178 new_offset = offset;
179 break;
180 case 1: /* SEEK_CUR */
181 new_offset = file->f_pos + offset;
182 break;
183 case 2: /* SEEK_END */
184 new_offset = vol->used_bytes + offset;
185 break;
186 default:
187 return -EINVAL;
188 }
189
190 if (new_offset < 0 || new_offset > vol->used_bytes) {
191 dbg_err("bad seek %lld", new_offset);
192 return -EINVAL;
193 }
194
195 dbg_msg("seek volume %d, offset %lld, origin %d, new offset %lld",
196 vol->vol_id, offset, origin, new_offset);
197
198 file->f_pos = new_offset;
199 return new_offset;
200}
201
202static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
203 loff_t *offp)
204{
205 struct ubi_volume_desc *desc = file->private_data;
206 struct ubi_volume *vol = desc->vol;
207 struct ubi_device *ubi = vol->ubi;
208 int err, lnum, off, len, vol_id = desc->vol->vol_id, tbuf_size;
209 size_t count_save = count;
210 void *tbuf;
211 uint64_t tmp;
212
213 dbg_msg("read %zd bytes from offset %lld of volume %d",
214 count, *offp, vol_id);
215
216 if (vol->updating) {
217 dbg_err("updating");
218 return -EBUSY;
219 }
220 if (vol->upd_marker) {
221 dbg_err("damaged volume, update marker is set");
222 return -EBADF;
223 }
224 if (*offp == vol->used_bytes || count == 0)
225 return 0;
226
227 if (vol->corrupted)
228 dbg_msg("read from corrupted volume %d", vol_id);
229
230 if (*offp + count > vol->used_bytes)
231 count_save = count = vol->used_bytes - *offp;
232
233 tbuf_size = vol->usable_leb_size;
234 if (count < tbuf_size)
235 tbuf_size = ALIGN(count, ubi->min_io_size);
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300236 tbuf = vmalloc(tbuf_size);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400237 if (!tbuf)
238 return -ENOMEM;
239
240 len = count > tbuf_size ? tbuf_size : count;
241
242 tmp = *offp;
243 off = do_div(tmp, vol->usable_leb_size);
244 lnum = tmp;
245
246 do {
247 cond_resched();
248
249 if (off + len >= vol->usable_leb_size)
250 len = vol->usable_leb_size - off;
251
252 err = ubi_eba_read_leb(ubi, vol_id, lnum, tbuf, off, len, 0);
253 if (err)
254 break;
255
256 off += len;
257 if (off == vol->usable_leb_size) {
258 lnum += 1;
259 off -= vol->usable_leb_size;
260 }
261
262 count -= len;
263 *offp += len;
264
265 err = copy_to_user(buf, tbuf, len);
266 if (err) {
267 err = -EFAULT;
268 break;
269 }
270
271 buf += len;
272 len = count > tbuf_size ? tbuf_size : count;
273 } while (count);
274
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300275 vfree(tbuf);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400276 return err ? err : count_save - count;
277}
278
279#ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
280
281/*
282 * This function allows to directly write to dynamic UBI volumes, without
283 * issuing the volume update operation. Available only as a debugging feature.
284 * Very useful for testing UBI.
285 */
286static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
287 size_t count, loff_t *offp)
288{
289 struct ubi_volume_desc *desc = file->private_data;
290 struct ubi_volume *vol = desc->vol;
291 struct ubi_device *ubi = vol->ubi;
292 int lnum, off, len, tbuf_size, vol_id = vol->vol_id, err = 0;
293 size_t count_save = count;
294 char *tbuf;
295 uint64_t tmp;
296
297 dbg_msg("requested: write %zd bytes to offset %lld of volume %u",
298 count, *offp, desc->vol->vol_id);
299
300 if (vol->vol_type == UBI_STATIC_VOLUME)
301 return -EROFS;
302
303 tmp = *offp;
304 off = do_div(tmp, vol->usable_leb_size);
305 lnum = tmp;
306
307 if (off % ubi->min_io_size) {
308 dbg_err("unaligned position");
309 return -EINVAL;
310 }
311
312 if (*offp + count > vol->used_bytes)
313 count_save = count = vol->used_bytes - *offp;
314
315 /* We can write only in fractions of the minimum I/O unit */
316 if (count % ubi->min_io_size) {
317 dbg_err("unaligned write length");
318 return -EINVAL;
319 }
320
321 tbuf_size = vol->usable_leb_size;
322 if (count < tbuf_size)
323 tbuf_size = ALIGN(count, ubi->min_io_size);
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300324 tbuf = vmalloc(tbuf_size);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400325 if (!tbuf)
326 return -ENOMEM;
327
328 len = count > tbuf_size ? tbuf_size : count;
329
330 while (count) {
331 cond_resched();
332
333 if (off + len >= vol->usable_leb_size)
334 len = vol->usable_leb_size - off;
335
336 err = copy_from_user(tbuf, buf, len);
337 if (err) {
338 err = -EFAULT;
339 break;
340 }
341
342 err = ubi_eba_write_leb(ubi, vol_id, lnum, tbuf, off, len,
343 UBI_UNKNOWN);
344 if (err)
345 break;
346
347 off += len;
348 if (off == vol->usable_leb_size) {
349 lnum += 1;
350 off -= vol->usable_leb_size;
351 }
352
353 count -= len;
354 *offp += len;
355 buf += len;
356 len = count > tbuf_size ? tbuf_size : count;
357 }
358
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300359 vfree(tbuf);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400360 return err ? err : count_save - count;
361}
362
363#else
364#define vol_cdev_direct_write(file, buf, count, offp) -EPERM
365#endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */
366
367static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
368 size_t count, loff_t *offp)
369{
370 int err = 0;
371 struct ubi_volume_desc *desc = file->private_data;
372 struct ubi_volume *vol = desc->vol;
373 struct ubi_device *ubi = vol->ubi;
374
375 if (!vol->updating)
376 return vol_cdev_direct_write(file, buf, count, offp);
377
378 err = ubi_more_update_data(ubi, vol->vol_id, buf, count);
379 if (err < 0) {
380 ubi_err("cannot write %zd bytes of update data", count);
381 return err;
382 }
383
384 if (err) {
385 /*
386 * Update is finished, @err contains number of actually written
387 * bytes now.
388 */
389 count = err;
390
391 err = ubi_check_volume(ubi, vol->vol_id);
392 if (err < 0)
393 return err;
394
395 if (err) {
396 ubi_warn("volume %d on UBI device %d is corrupted",
397 vol->vol_id, ubi->ubi_num);
398 vol->corrupted = 1;
399 }
400 vol->checked = 1;
Artem Bityutskiy941dfb02007-05-05 16:33:13 +0300401 ubi_gluebi_updated(vol);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400402 revoke_exclusive(desc, UBI_READWRITE);
403 }
404
405 *offp += count;
406 return count;
407}
408
409static int vol_cdev_ioctl(struct inode *inode, struct file *file,
410 unsigned int cmd, 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
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400418 switch (cmd) {
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400419 /* 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 = vol->reserved_pebs * (ubi->leb_size-vol->data_pad);
441 if (bytes < 0 || bytes > rsvd_bytes) {
442 err = -EINVAL;
443 break;
444 }
445
446 err = get_exclusive(desc);
447 if (err < 0)
448 break;
449
450 err = ubi_start_update(ubi, vol->vol_id, bytes);
451 if (bytes == 0)
452 revoke_exclusive(desc, UBI_READWRITE);
453
454 file->f_pos = 0;
455 break;
456 }
457
458#ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
459 /* Logical eraseblock erasure command */
460 case UBI_IOCEBER:
461 {
462 int32_t lnum;
463
Christoph Hellwigbf078032007-05-17 16:32:10 +0200464 err = get_user(lnum, (__user int32_t *)argp);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400465 if (err) {
466 err = -EFAULT;
467 break;
468 }
469
470 if (desc->mode == UBI_READONLY) {
471 err = -EROFS;
472 break;
473 }
474
475 if (lnum < 0 || lnum >= vol->reserved_pebs) {
476 err = -EINVAL;
477 break;
478 }
479
480 if (vol->vol_type != UBI_DYNAMIC_VOLUME) {
481 err = -EROFS;
482 break;
483 }
484
485 dbg_msg("erase LEB %d:%d", vol->vol_id, lnum);
486 err = ubi_eba_unmap_leb(ubi, vol->vol_id, lnum);
487 if (err)
488 break;
489
490 err = ubi_wl_flush(ubi);
491 break;
492 }
493#endif
494
495 default:
496 err = -ENOTTY;
497 break;
498 }
499
500 return err;
501}
502
503/**
504 * verify_mkvol_req - verify volume creation request.
505 * @ubi: UBI device description object
506 * @req: the request to check
507 *
508 * This function zero if the request is correct, and %-EINVAL if not.
509 */
510static int verify_mkvol_req(const struct ubi_device *ubi,
511 const struct ubi_mkvol_req *req)
512{
513 int n, err = -EINVAL;
514
515 if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
516 req->name_len < 0)
517 goto bad;
518
519 if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
520 req->vol_id != UBI_VOL_NUM_AUTO)
521 goto bad;
522
523 if (req->alignment == 0)
524 goto bad;
525
526 if (req->bytes == 0)
527 goto bad;
528
529 if (req->vol_type != UBI_DYNAMIC_VOLUME &&
530 req->vol_type != UBI_STATIC_VOLUME)
531 goto bad;
532
533 if (req->alignment > ubi->leb_size)
534 goto bad;
535
536 n = req->alignment % ubi->min_io_size;
537 if (req->alignment != 1 && n)
538 goto bad;
539
540 if (req->name_len > UBI_VOL_NAME_MAX) {
541 err = -ENAMETOOLONG;
542 goto bad;
543 }
544
545 return 0;
546
547bad:
548 dbg_err("bad volume creation request");
549 ubi_dbg_dump_mkvol_req(req);
550 return err;
551}
552
553/**
554 * verify_rsvol_req - verify volume re-size request.
555 * @ubi: UBI device description object
556 * @req: the request to check
557 *
558 * This function returns zero if the request is correct, and %-EINVAL if not.
559 */
560static int verify_rsvol_req(const struct ubi_device *ubi,
561 const struct ubi_rsvol_req *req)
562{
563 if (req->bytes <= 0)
564 return -EINVAL;
565
566 if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
567 return -EINVAL;
568
569 return 0;
570}
571
572static int ubi_cdev_ioctl(struct inode *inode, struct file *file,
573 unsigned int cmd, unsigned long arg)
574{
575 int err = 0;
576 struct ubi_device *ubi;
577 struct ubi_volume_desc *desc;
578 void __user *argp = (void __user *)arg;
579
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400580 if (!capable(CAP_SYS_RESOURCE))
581 return -EPERM;
582
583 ubi = major_to_device(imajor(inode));
584 if (IS_ERR(ubi))
585 return PTR_ERR(ubi);
586
587 switch (cmd) {
588 /* Create volume command */
589 case UBI_IOCMKVOL:
590 {
591 struct ubi_mkvol_req req;
592
593 dbg_msg("create volume");
Christoph Hellwigbf078032007-05-17 16:32:10 +0200594 err = copy_from_user(&req, argp,
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400595 sizeof(struct ubi_mkvol_req));
596 if (err) {
597 err = -EFAULT;
598 break;
599 }
600
601 err = verify_mkvol_req(ubi, &req);
602 if (err)
603 break;
604
605 req.name[req.name_len] = '\0';
606
607 err = ubi_create_volume(ubi, &req);
608 if (err)
609 break;
610
Christoph Hellwigbf078032007-05-17 16:32:10 +0200611 err = put_user(req.vol_id, (__user int32_t *)argp);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400612 if (err)
613 err = -EFAULT;
614
615 break;
616 }
617
618 /* Remove volume command */
619 case UBI_IOCRMVOL:
620 {
621 int vol_id;
622
623 dbg_msg("remove volume");
Christoph Hellwigbf078032007-05-17 16:32:10 +0200624 err = get_user(vol_id, (__user int32_t *)argp);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400625 if (err) {
626 err = -EFAULT;
627 break;
628 }
629
630 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
631 if (IS_ERR(desc)) {
632 err = PTR_ERR(desc);
633 break;
634 }
635
636 err = ubi_remove_volume(desc);
637 if (err)
638 ubi_close_volume(desc);
639
640 break;
641 }
642
643 /* Re-size volume command */
644 case UBI_IOCRSVOL:
645 {
646 int pebs;
647 uint64_t tmp;
648 struct ubi_rsvol_req req;
649
650 dbg_msg("re-size volume");
Christoph Hellwigbf078032007-05-17 16:32:10 +0200651 err = copy_from_user(&req, argp,
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400652 sizeof(struct ubi_rsvol_req));
653 if (err) {
654 err = -EFAULT;
655 break;
656 }
657
658 err = verify_rsvol_req(ubi, &req);
659 if (err)
660 break;
661
662 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
663 if (IS_ERR(desc)) {
664 err = PTR_ERR(desc);
665 break;
666 }
667
668 tmp = req.bytes;
669 pebs = !!do_div(tmp, desc->vol->usable_leb_size);
670 pebs += tmp;
671
672 err = ubi_resize_volume(desc, pebs);
673 ubi_close_volume(desc);
674 break;
675 }
676
677 default:
678 err = -ENOTTY;
679 break;
680 }
681
682 return err;
683}
684
685/* UBI character device operations */
686struct file_operations ubi_cdev_operations = {
687 .owner = THIS_MODULE,
688 .ioctl = ubi_cdev_ioctl,
Artem Bityutskiyf800f092007-05-06 16:45:43 +0300689 .llseek = no_llseek,
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400690};
691
692/* UBI volume character device operations */
693struct file_operations ubi_vol_cdev_operations = {
694 .owner = THIS_MODULE,
695 .open = vol_cdev_open,
696 .release = vol_cdev_release,
697 .llseek = vol_cdev_llseek,
698 .read = vol_cdev_read,
699 .write = vol_cdev_write,
Artem Bityutskiyf800f092007-05-06 16:45:43 +0300700 .ioctl = vol_cdev_ioctl,
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400701};