1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) International Business Machines Corp., 2006
4 * Copyright (c) Nokia Corporation, 2007
5 *
6 * Author: Artem Bityutskiy (Битюцкий Артём),
7 * Frank Haverkamp
8 */
9
10 /*
11 * This file includes UBI initialization and building of UBI devices.
12 *
13 * When UBI is initialized, it attaches all the MTD devices specified as the
14 * module load parameters or the kernel boot parameters. If MTD devices were
15 * specified, UBI does not attach any MTD device, but it is possible to do
16 * later using the "UBI control device".
17 */
18
19 #include <linux/err.h>
20 #include <linux/module.h>
21 #include <linux/moduleparam.h>
22 #include <linux/stringify.h>
23 #include <linux/namei.h>
24 #include <linux/stat.h>
25 #include <linux/miscdevice.h>
26 #include <linux/mtd/partitions.h>
27 #include <linux/log2.h>
28 #include <linux/kthread.h>
29 #include <linux/kernel.h>
30 #include <linux/slab.h>
31 #include <linux/major.h>
32 #include "ubi.h"
33
34 /* Maximum length of the 'mtd=' parameter */
35 #define MTD_PARAM_LEN_MAX 64
36
37 /* Maximum number of comma-separated items in the 'mtd=' parameter */
38 #define MTD_PARAM_MAX_COUNT 4
39
40 /* Maximum value for the number of bad PEBs per 1024 PEBs */
41 #define MAX_MTD_UBI_BEB_LIMIT 768
42
43 #ifdef CONFIG_MTD_UBI_MODULE
44 #define ubi_is_module() 1
45 #else
46 #define ubi_is_module() 0
47 #endif
48
49 /**
50 * struct mtd_dev_param - MTD device parameter description data structure.
51 * @name: MTD character device node path, MTD device name, or MTD device number
52 * string
53 * @ubi_num: UBI number
54 * @vid_hdr_offs: VID header offset
55 * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
56 */
57 struct mtd_dev_param {
58 char name[MTD_PARAM_LEN_MAX];
59 int ubi_num;
60 int vid_hdr_offs;
61 int max_beb_per1024;
62 };
63
64 /* Numbers of elements set in the @mtd_dev_param array */
65 static int mtd_devs;
66
67 /* MTD devices specification parameters */
68 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
69 #ifdef CONFIG_MTD_UBI_FASTMAP
70 /* UBI module parameter to enable fastmap automatically on non-fastmap images */
71 static bool fm_autoconvert;
72 static bool fm_debug;
73 #endif
74
75 /* Slab cache for wear-leveling entries */
76 struct kmem_cache *ubi_wl_entry_slab;
77
78 /* UBI control character device */
79 static struct miscdevice ubi_ctrl_cdev = {
80 .minor = MISC_DYNAMIC_MINOR,
81 .name = "ubi_ctrl",
82 .fops = &ubi_ctrl_cdev_operations,
83 };
84
85 /* All UBI devices in system */
86 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
87
88 /* Serializes UBI devices creations and removals */
89 DEFINE_MUTEX(ubi_devices_mutex);
90
91 /* Protects @ubi_devices and @ubi->ref_count */
92 static DEFINE_SPINLOCK(ubi_devices_lock);
93
94 /* "Show" method for files in '/<sysfs>/class/ubi/' */
95 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
version_show(struct class * class,struct class_attribute * attr,char * buf)96 static ssize_t version_show(struct class *class, struct class_attribute *attr,
97 char *buf)
98 {
99 return sprintf(buf, "%d\n", UBI_VERSION);
100 }
101 static CLASS_ATTR_RO(version);
102
103 static struct attribute *ubi_class_attrs[] = {
104 &class_attr_version.attr,
105 NULL,
106 };
107 ATTRIBUTE_GROUPS(ubi_class);
108
109 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
110 struct class ubi_class = {
111 .name = UBI_NAME_STR,
112 .owner = THIS_MODULE,
113 .class_groups = ubi_class_groups,
114 };
115
116 static ssize_t dev_attribute_show(struct device *dev,
117 struct device_attribute *attr, char *buf);
118
119 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
120 static struct device_attribute dev_eraseblock_size =
121 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
122 static struct device_attribute dev_avail_eraseblocks =
123 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
124 static struct device_attribute dev_total_eraseblocks =
125 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
126 static struct device_attribute dev_volumes_count =
127 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
128 static struct device_attribute dev_max_ec =
129 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
130 static struct device_attribute dev_reserved_for_bad =
131 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
132 static struct device_attribute dev_bad_peb_count =
133 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
134 static struct device_attribute dev_max_vol_count =
135 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
136 static struct device_attribute dev_min_io_size =
137 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
138 static struct device_attribute dev_bgt_enabled =
139 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
140 static struct device_attribute dev_mtd_num =
141 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
142 static struct device_attribute dev_ro_mode =
143 __ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
144
145 /**
146 * ubi_volume_notify - send a volume change notification.
147 * @ubi: UBI device description object
148 * @vol: volume description object of the changed volume
149 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
150 *
151 * This is a helper function which notifies all subscribers about a volume
152 * change event (creation, removal, re-sizing, re-naming, updating). Returns
153 * zero in case of success and a negative error code in case of failure.
154 */
ubi_volume_notify(struct ubi_device * ubi,struct ubi_volume * vol,int ntype)155 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
156 {
157 int ret;
158 struct ubi_notification nt;
159
160 ubi_do_get_device_info(ubi, &nt.di);
161 ubi_do_get_volume_info(ubi, vol, &nt.vi);
162
163 switch (ntype) {
164 case UBI_VOLUME_ADDED:
165 case UBI_VOLUME_REMOVED:
166 case UBI_VOLUME_RESIZED:
167 case UBI_VOLUME_RENAMED:
168 ret = ubi_update_fastmap(ubi);
169 if (ret)
170 ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
171 }
172
173 return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
174 }
175
176 /**
177 * ubi_notify_all - send a notification to all volumes.
178 * @ubi: UBI device description object
179 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
180 * @nb: the notifier to call
181 *
182 * This function walks all volumes of UBI device @ubi and sends the @ntype
183 * notification for each volume. If @nb is %NULL, then all registered notifiers
184 * are called, otherwise only the @nb notifier is called. Returns the number of
185 * sent notifications.
186 */
ubi_notify_all(struct ubi_device * ubi,int ntype,struct notifier_block * nb)187 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
188 {
189 struct ubi_notification nt;
190 int i, count = 0;
191
192 ubi_do_get_device_info(ubi, &nt.di);
193
194 mutex_lock(&ubi->device_mutex);
195 for (i = 0; i < ubi->vtbl_slots; i++) {
196 /*
197 * Since the @ubi->device is locked, and we are not going to
198 * change @ubi->volumes, we do not have to lock
199 * @ubi->volumes_lock.
200 */
201 if (!ubi->volumes[i])
202 continue;
203
204 ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
205 if (nb)
206 nb->notifier_call(nb, ntype, &nt);
207 else
208 blocking_notifier_call_chain(&ubi_notifiers, ntype,
209 &nt);
210 count += 1;
211 }
212 mutex_unlock(&ubi->device_mutex);
213
214 return count;
215 }
216
217 /**
218 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
219 * @nb: the notifier to call
220 *
221 * This function walks all UBI devices and volumes and sends the
222 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
223 * registered notifiers are called, otherwise only the @nb notifier is called.
224 * Returns the number of sent notifications.
225 */
ubi_enumerate_volumes(struct notifier_block * nb)226 int ubi_enumerate_volumes(struct notifier_block *nb)
227 {
228 int i, count = 0;
229
230 /*
231 * Since the @ubi_devices_mutex is locked, and we are not going to
232 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
233 */
234 for (i = 0; i < UBI_MAX_DEVICES; i++) {
235 struct ubi_device *ubi = ubi_devices[i];
236
237 if (!ubi)
238 continue;
239 count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
240 }
241
242 return count;
243 }
244
245 /**
246 * ubi_get_device - get UBI device.
247 * @ubi_num: UBI device number
248 *
249 * This function returns UBI device description object for UBI device number
250 * @ubi_num, or %NULL if the device does not exist. This function increases the
251 * device reference count to prevent removal of the device. In other words, the
252 * device cannot be removed if its reference count is not zero.
253 */
ubi_get_device(int ubi_num)254 struct ubi_device *ubi_get_device(int ubi_num)
255 {
256 struct ubi_device *ubi;
257
258 spin_lock(&ubi_devices_lock);
259 ubi = ubi_devices[ubi_num];
260 if (ubi) {
261 ubi_assert(ubi->ref_count >= 0);
262 ubi->ref_count += 1;
263 get_device(&ubi->dev);
264 }
265 spin_unlock(&ubi_devices_lock);
266
267 return ubi;
268 }
269
270 /**
271 * ubi_put_device - drop an UBI device reference.
272 * @ubi: UBI device description object
273 */
ubi_put_device(struct ubi_device * ubi)274 void ubi_put_device(struct ubi_device *ubi)
275 {
276 spin_lock(&ubi_devices_lock);
277 ubi->ref_count -= 1;
278 put_device(&ubi->dev);
279 spin_unlock(&ubi_devices_lock);
280 }
281
282 /**
283 * ubi_get_by_major - get UBI device by character device major number.
284 * @major: major number
285 *
286 * This function is similar to 'ubi_get_device()', but it searches the device
287 * by its major number.
288 */
ubi_get_by_major(int major)289 struct ubi_device *ubi_get_by_major(int major)
290 {
291 int i;
292 struct ubi_device *ubi;
293
294 spin_lock(&ubi_devices_lock);
295 for (i = 0; i < UBI_MAX_DEVICES; i++) {
296 ubi = ubi_devices[i];
297 if (ubi && MAJOR(ubi->cdev.dev) == major) {
298 ubi_assert(ubi->ref_count >= 0);
299 ubi->ref_count += 1;
300 get_device(&ubi->dev);
301 spin_unlock(&ubi_devices_lock);
302 return ubi;
303 }
304 }
305 spin_unlock(&ubi_devices_lock);
306
307 return NULL;
308 }
309
310 /**
311 * ubi_major2num - get UBI device number by character device major number.
312 * @major: major number
313 *
314 * This function searches UBI device number object by its major number. If UBI
315 * device was not found, this function returns -ENODEV, otherwise the UBI device
316 * number is returned.
317 */
ubi_major2num(int major)318 int ubi_major2num(int major)
319 {
320 int i, ubi_num = -ENODEV;
321
322 spin_lock(&ubi_devices_lock);
323 for (i = 0; i < UBI_MAX_DEVICES; i++) {
324 struct ubi_device *ubi = ubi_devices[i];
325
326 if (ubi && MAJOR(ubi->cdev.dev) == major) {
327 ubi_num = ubi->ubi_num;
328 break;
329 }
330 }
331 spin_unlock(&ubi_devices_lock);
332
333 return ubi_num;
334 }
335
336 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
dev_attribute_show(struct device * dev,struct device_attribute * attr,char * buf)337 static ssize_t dev_attribute_show(struct device *dev,
338 struct device_attribute *attr, char *buf)
339 {
340 ssize_t ret;
341 struct ubi_device *ubi;
342
343 /*
344 * The below code looks weird, but it actually makes sense. We get the
345 * UBI device reference from the contained 'struct ubi_device'. But it
346 * is unclear if the device was removed or not yet. Indeed, if the
347 * device was removed before we increased its reference count,
348 * 'ubi_get_device()' will return -ENODEV and we fail.
349 *
350 * Remember, 'struct ubi_device' is freed in the release function, so
351 * we still can use 'ubi->ubi_num'.
352 */
353 ubi = container_of(dev, struct ubi_device, dev);
354
355 if (attr == &dev_eraseblock_size)
356 ret = sprintf(buf, "%d\n", ubi->leb_size);
357 else if (attr == &dev_avail_eraseblocks)
358 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
359 else if (attr == &dev_total_eraseblocks)
360 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
361 else if (attr == &dev_volumes_count)
362 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
363 else if (attr == &dev_max_ec)
364 ret = sprintf(buf, "%d\n", ubi->max_ec);
365 else if (attr == &dev_reserved_for_bad)
366 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
367 else if (attr == &dev_bad_peb_count)
368 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
369 else if (attr == &dev_max_vol_count)
370 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
371 else if (attr == &dev_min_io_size)
372 ret = sprintf(buf, "%d\n", ubi->min_io_size);
373 else if (attr == &dev_bgt_enabled)
374 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
375 else if (attr == &dev_mtd_num)
376 ret = sprintf(buf, "%d\n", ubi->mtd->index);
377 else if (attr == &dev_ro_mode)
378 ret = sprintf(buf, "%d\n", ubi->ro_mode);
379 else
380 ret = -EINVAL;
381
382 return ret;
383 }
384
385 static struct attribute *ubi_dev_attrs[] = {
386 &dev_eraseblock_size.attr,
387 &dev_avail_eraseblocks.attr,
388 &dev_total_eraseblocks.attr,
389 &dev_volumes_count.attr,
390 &dev_max_ec.attr,
391 &dev_reserved_for_bad.attr,
392 &dev_bad_peb_count.attr,
393 &dev_max_vol_count.attr,
394 &dev_min_io_size.attr,
395 &dev_bgt_enabled.attr,
396 &dev_mtd_num.attr,
397 &dev_ro_mode.attr,
398 NULL
399 };
400 ATTRIBUTE_GROUPS(ubi_dev);
401
dev_release(struct device * dev)402 static void dev_release(struct device *dev)
403 {
404 struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
405
406 kfree(ubi);
407 }
408
409 /**
410 * kill_volumes - destroy all user volumes.
411 * @ubi: UBI device description object
412 */
kill_volumes(struct ubi_device * ubi)413 static void kill_volumes(struct ubi_device *ubi)
414 {
415 int i;
416
417 for (i = 0; i < ubi->vtbl_slots; i++)
418 if (ubi->volumes[i])
419 ubi_free_volume(ubi, ubi->volumes[i]);
420 }
421
422 /**
423 * uif_init - initialize user interfaces for an UBI device.
424 * @ubi: UBI device description object
425 *
426 * This function initializes various user interfaces for an UBI device. If the
427 * initialization fails at an early stage, this function frees all the
428 * resources it allocated, returns an error.
429 *
430 * This function returns zero in case of success and a negative error code in
431 * case of failure.
432 */
uif_init(struct ubi_device * ubi)433 static int uif_init(struct ubi_device *ubi)
434 {
435 int i, err;
436 dev_t dev;
437
438 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
439
440 /*
441 * Major numbers for the UBI character devices are allocated
442 * dynamically. Major numbers of volume character devices are
443 * equivalent to ones of the corresponding UBI character device. Minor
444 * numbers of UBI character devices are 0, while minor numbers of
445 * volume character devices start from 1. Thus, we allocate one major
446 * number and ubi->vtbl_slots + 1 minor numbers.
447 */
448 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
449 if (err) {
450 ubi_err(ubi, "cannot register UBI character devices");
451 return err;
452 }
453
454 ubi->dev.devt = dev;
455
456 ubi_assert(MINOR(dev) == 0);
457 cdev_init(&ubi->cdev, &ubi_cdev_operations);
458 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
459 ubi->cdev.owner = THIS_MODULE;
460
461 dev_set_name(&ubi->dev, UBI_NAME_STR "%d", ubi->ubi_num);
462 err = cdev_device_add(&ubi->cdev, &ubi->dev);
463 if (err)
464 goto out_unreg;
465
466 for (i = 0; i < ubi->vtbl_slots; i++)
467 if (ubi->volumes[i]) {
468 err = ubi_add_volume(ubi, ubi->volumes[i]);
469 if (err) {
470 ubi_err(ubi, "cannot add volume %d", i);
471 ubi->volumes[i] = NULL;
472 goto out_volumes;
473 }
474 }
475
476 return 0;
477
478 out_volumes:
479 kill_volumes(ubi);
480 cdev_device_del(&ubi->cdev, &ubi->dev);
481 out_unreg:
482 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
483 ubi_err(ubi, "cannot initialize UBI %s, error %d",
484 ubi->ubi_name, err);
485 return err;
486 }
487
488 /**
489 * uif_close - close user interfaces for an UBI device.
490 * @ubi: UBI device description object
491 *
492 * Note, since this function un-registers UBI volume device objects (@vol->dev),
493 * the memory allocated voe the volumes is freed as well (in the release
494 * function).
495 */
uif_close(struct ubi_device * ubi)496 static void uif_close(struct ubi_device *ubi)
497 {
498 kill_volumes(ubi);
499 cdev_device_del(&ubi->cdev, &ubi->dev);
500 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
501 }
502
503 /**
504 * ubi_free_volumes_from - free volumes from specific index.
505 * @ubi: UBI device description object
506 * @from: the start index used for volume free.
507 */
ubi_free_volumes_from(struct ubi_device * ubi,int from)508 static void ubi_free_volumes_from(struct ubi_device *ubi, int from)
509 {
510 int i;
511
512 for (i = from; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
513 if (!ubi->volumes[i])
514 continue;
515 ubi_eba_replace_table(ubi->volumes[i], NULL);
516 ubi_fastmap_destroy_checkmap(ubi->volumes[i]);
517 kfree(ubi->volumes[i]);
518 ubi->volumes[i] = NULL;
519 }
520 }
521
522 /**
523 * ubi_free_all_volumes - free all volumes.
524 * @ubi: UBI device description object
525 */
ubi_free_all_volumes(struct ubi_device * ubi)526 void ubi_free_all_volumes(struct ubi_device *ubi)
527 {
528 ubi_free_volumes_from(ubi, 0);
529 }
530
531 /**
532 * ubi_free_internal_volumes - free internal volumes.
533 * @ubi: UBI device description object
534 */
ubi_free_internal_volumes(struct ubi_device * ubi)535 void ubi_free_internal_volumes(struct ubi_device *ubi)
536 {
537 ubi_free_volumes_from(ubi, ubi->vtbl_slots);
538 }
539
get_bad_peb_limit(const struct ubi_device * ubi,int max_beb_per1024)540 static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
541 {
542 int limit, device_pebs;
543 uint64_t device_size;
544
545 if (!max_beb_per1024) {
546 /*
547 * Since max_beb_per1024 has not been set by the user in either
548 * the cmdline or Kconfig, use mtd_max_bad_blocks to set the
549 * limit if it is supported by the device.
550 */
551 limit = mtd_max_bad_blocks(ubi->mtd, 0, ubi->mtd->size);
552 if (limit < 0)
553 return 0;
554 return limit;
555 }
556
557 /*
558 * Here we are using size of the entire flash chip and
559 * not just the MTD partition size because the maximum
560 * number of bad eraseblocks is a percentage of the
561 * whole device and bad eraseblocks are not fairly
562 * distributed over the flash chip. So the worst case
563 * is that all the bad eraseblocks of the chip are in
564 * the MTD partition we are attaching (ubi->mtd).
565 */
566 device_size = mtd_get_device_size(ubi->mtd);
567 device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
568 limit = mult_frac(device_pebs, max_beb_per1024, 1024);
569
570 /* Round it up */
571 if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
572 limit += 1;
573
574 return limit;
575 }
576
577 /**
578 * io_init - initialize I/O sub-system for a given UBI device.
579 * @ubi: UBI device description object
580 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
581 *
582 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
583 * assumed:
584 * o EC header is always at offset zero - this cannot be changed;
585 * o VID header starts just after the EC header at the closest address
586 * aligned to @io->hdrs_min_io_size;
587 * o data starts just after the VID header at the closest address aligned to
588 * @io->min_io_size
589 *
590 * This function returns zero in case of success and a negative error code in
591 * case of failure.
592 */
io_init(struct ubi_device * ubi,int max_beb_per1024)593 static int io_init(struct ubi_device *ubi, int max_beb_per1024)
594 {
595 dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
596 dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
597
598 if (ubi->mtd->numeraseregions != 0) {
599 /*
600 * Some flashes have several erase regions. Different regions
601 * may have different eraseblock size and other
602 * characteristics. It looks like mostly multi-region flashes
603 * have one "main" region and one or more small regions to
604 * store boot loader code or boot parameters or whatever. I
605 * guess we should just pick the largest region. But this is
606 * not implemented.
607 */
608 ubi_err(ubi, "multiple regions, not implemented");
609 return -EINVAL;
610 }
611
612 if (ubi->vid_hdr_offset < 0)
613 return -EINVAL;
614
615 /*
616 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
617 * physical eraseblocks maximum.
618 */
619
620 ubi->peb_size = ubi->mtd->erasesize;
621 ubi->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
622 ubi->flash_size = ubi->mtd->size;
623
624 if (mtd_can_have_bb(ubi->mtd)) {
625 ubi->bad_allowed = 1;
626 ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
627 }
628
629 if (ubi->mtd->type == MTD_NORFLASH)
630 ubi->nor_flash = 1;
631
632 ubi->min_io_size = ubi->mtd->writesize;
633 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
634
635 /*
636 * Make sure minimal I/O unit is power of 2. Note, there is no
637 * fundamental reason for this assumption. It is just an optimization
638 * which allows us to avoid costly division operations.
639 */
640 if (!is_power_of_2(ubi->min_io_size)) {
641 ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
642 ubi->min_io_size);
643 return -EINVAL;
644 }
645
646 ubi_assert(ubi->hdrs_min_io_size > 0);
647 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
648 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
649
650 ubi->max_write_size = ubi->mtd->writebufsize;
651 /*
652 * Maximum write size has to be greater or equivalent to min. I/O
653 * size, and be multiple of min. I/O size.
654 */
655 if (ubi->max_write_size < ubi->min_io_size ||
656 ubi->max_write_size % ubi->min_io_size ||
657 !is_power_of_2(ubi->max_write_size)) {
658 ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
659 ubi->max_write_size, ubi->min_io_size);
660 return -EINVAL;
661 }
662
663 /* Calculate default aligned sizes of EC and VID headers */
664 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
665 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
666
667 dbg_gen("min_io_size %d", ubi->min_io_size);
668 dbg_gen("max_write_size %d", ubi->max_write_size);
669 dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
670 dbg_gen("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
671 dbg_gen("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
672
673 if (ubi->vid_hdr_offset == 0)
674 /* Default offset */
675 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
676 ubi->ec_hdr_alsize;
677 else {
678 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
679 ~(ubi->hdrs_min_io_size - 1);
680 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
681 ubi->vid_hdr_aloffset;
682 }
683
684 /*
685 * Memory allocation for VID header is ubi->vid_hdr_alsize
686 * which is described in comments in io.c.
687 * Make sure VID header shift + UBI_VID_HDR_SIZE not exceeds
688 * ubi->vid_hdr_alsize, so that all vid header operations
689 * won't access memory out of bounds.
690 */
691 if ((ubi->vid_hdr_shift + UBI_VID_HDR_SIZE) > ubi->vid_hdr_alsize) {
692 ubi_err(ubi, "Invalid VID header offset %d, VID header shift(%d)"
693 " + VID header size(%zu) > VID header aligned size(%d).",
694 ubi->vid_hdr_offset, ubi->vid_hdr_shift,
695 UBI_VID_HDR_SIZE, ubi->vid_hdr_alsize);
696 return -EINVAL;
697 }
698
699 /* Similar for the data offset */
700 ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
701 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
702
703 dbg_gen("vid_hdr_offset %d", ubi->vid_hdr_offset);
704 dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
705 dbg_gen("vid_hdr_shift %d", ubi->vid_hdr_shift);
706 dbg_gen("leb_start %d", ubi->leb_start);
707
708 /* The shift must be aligned to 32-bit boundary */
709 if (ubi->vid_hdr_shift % 4) {
710 ubi_err(ubi, "unaligned VID header shift %d",
711 ubi->vid_hdr_shift);
712 return -EINVAL;
713 }
714
715 /* Check sanity */
716 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
717 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
718 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
719 ubi->leb_start & (ubi->min_io_size - 1)) {
720 ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
721 ubi->vid_hdr_offset, ubi->leb_start);
722 return -EINVAL;
723 }
724
725 /*
726 * Set maximum amount of physical erroneous eraseblocks to be 10%.
727 * Erroneous PEB are those which have read errors.
728 */
729 ubi->max_erroneous = ubi->peb_count / 10;
730 if (ubi->max_erroneous < 16)
731 ubi->max_erroneous = 16;
732 dbg_gen("max_erroneous %d", ubi->max_erroneous);
733
734 /*
735 * It may happen that EC and VID headers are situated in one minimal
736 * I/O unit. In this case we can only accept this UBI image in
737 * read-only mode.
738 */
739 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
740 ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
741 ubi->ro_mode = 1;
742 }
743
744 ubi->leb_size = ubi->peb_size - ubi->leb_start;
745
746 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
747 ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
748 ubi->mtd->index);
749 ubi->ro_mode = 1;
750 }
751
752 /*
753 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
754 * unfortunately, MTD does not provide this information. We should loop
755 * over all physical eraseblocks and invoke mtd->block_is_bad() for
756 * each physical eraseblock. So, we leave @ubi->bad_peb_count
757 * uninitialized so far.
758 */
759
760 return 0;
761 }
762
763 /**
764 * autoresize - re-size the volume which has the "auto-resize" flag set.
765 * @ubi: UBI device description object
766 * @vol_id: ID of the volume to re-size
767 *
768 * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
769 * the volume table to the largest possible size. See comments in ubi-header.h
770 * for more description of the flag. Returns zero in case of success and a
771 * negative error code in case of failure.
772 */
autoresize(struct ubi_device * ubi,int vol_id)773 static int autoresize(struct ubi_device *ubi, int vol_id)
774 {
775 struct ubi_volume_desc desc;
776 struct ubi_volume *vol = ubi->volumes[vol_id];
777 int err, old_reserved_pebs = vol->reserved_pebs;
778
779 if (ubi->ro_mode) {
780 ubi_warn(ubi, "skip auto-resize because of R/O mode");
781 return 0;
782 }
783
784 /*
785 * Clear the auto-resize flag in the volume in-memory copy of the
786 * volume table, and 'ubi_resize_volume()' will propagate this change
787 * to the flash.
788 */
789 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
790
791 if (ubi->avail_pebs == 0) {
792 struct ubi_vtbl_record vtbl_rec;
793
794 /*
795 * No available PEBs to re-size the volume, clear the flag on
796 * flash and exit.
797 */
798 vtbl_rec = ubi->vtbl[vol_id];
799 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
800 if (err)
801 ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
802 vol_id);
803 } else {
804 desc.vol = vol;
805 err = ubi_resize_volume(&desc,
806 old_reserved_pebs + ubi->avail_pebs);
807 if (err)
808 ubi_err(ubi, "cannot auto-resize volume %d",
809 vol_id);
810 }
811
812 if (err)
813 return err;
814
815 ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
816 vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
817 return 0;
818 }
819
820 /**
821 * ubi_attach_mtd_dev - attach an MTD device.
822 * @mtd: MTD device description object
823 * @ubi_num: number to assign to the new UBI device
824 * @vid_hdr_offset: VID header offset
825 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
826 * @disable_fm: whether disable fastmap
827 *
828 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
829 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
830 * which case this function finds a vacant device number and assigns it
831 * automatically. Returns the new UBI device number in case of success and a
832 * negative error code in case of failure.
833 *
834 * If @disable_fm is true, ubi doesn't create new fastmap even the module param
835 * 'fm_autoconvert' is set, and existed old fastmap will be destroyed after
836 * doing full scanning.
837 *
838 * Note, the invocations of this function has to be serialized by the
839 * @ubi_devices_mutex.
840 */
ubi_attach_mtd_dev(struct mtd_info * mtd,int ubi_num,int vid_hdr_offset,int max_beb_per1024,bool disable_fm)841 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
842 int vid_hdr_offset, int max_beb_per1024, bool disable_fm)
843 {
844 struct ubi_device *ubi;
845 int i, err;
846
847 if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
848 return -EINVAL;
849
850 if (!max_beb_per1024)
851 max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
852
853 /*
854 * Check if we already have the same MTD device attached.
855 *
856 * Note, this function assumes that UBI devices creations and deletions
857 * are serialized, so it does not take the &ubi_devices_lock.
858 */
859 for (i = 0; i < UBI_MAX_DEVICES; i++) {
860 ubi = ubi_devices[i];
861 if (ubi && mtd->index == ubi->mtd->index) {
862 pr_err("ubi: mtd%d is already attached to ubi%d\n",
863 mtd->index, i);
864 return -EEXIST;
865 }
866 }
867
868 /*
869 * Make sure this MTD device is not emulated on top of an UBI volume
870 * already. Well, generally this recursion works fine, but there are
871 * different problems like the UBI module takes a reference to itself
872 * by attaching (and thus, opening) the emulated MTD device. This
873 * results in inability to unload the module. And in general it makes
874 * no sense to attach emulated MTD devices, so we prohibit this.
875 */
876 if (mtd->type == MTD_UBIVOLUME) {
877 pr_err("ubi: refuse attaching mtd%d - it is already emulated on top of UBI\n",
878 mtd->index);
879 return -EINVAL;
880 }
881
882 /*
883 * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes.
884 * MLC NAND is different and needs special care, otherwise UBI or UBIFS
885 * will die soon and you will lose all your data.
886 * Relax this rule if the partition we're attaching to operates in SLC
887 * mode.
888 */
889 if (mtd->type == MTD_MLCNANDFLASH &&
890 !(mtd->flags & MTD_SLC_ON_MLC_EMULATION)) {
891 pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n",
892 mtd->index);
893 return -EINVAL;
894 }
895
896 /* UBI cannot work on flashes with zero erasesize. */
897 if (!mtd->erasesize) {
898 pr_err("ubi: refuse attaching mtd%d - zero erasesize flash is not supported\n",
899 mtd->index);
900 return -EINVAL;
901 }
902
903 if (ubi_num == UBI_DEV_NUM_AUTO) {
904 /* Search for an empty slot in the @ubi_devices array */
905 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
906 if (!ubi_devices[ubi_num])
907 break;
908 if (ubi_num == UBI_MAX_DEVICES) {
909 pr_err("ubi: only %d UBI devices may be created\n",
910 UBI_MAX_DEVICES);
911 return -ENFILE;
912 }
913 } else {
914 if (ubi_num >= UBI_MAX_DEVICES)
915 return -EINVAL;
916
917 /* Make sure ubi_num is not busy */
918 if (ubi_devices[ubi_num]) {
919 pr_err("ubi: ubi%i already exists\n", ubi_num);
920 return -EEXIST;
921 }
922 }
923
924 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
925 if (!ubi)
926 return -ENOMEM;
927
928 device_initialize(&ubi->dev);
929 ubi->dev.release = dev_release;
930 ubi->dev.class = &ubi_class;
931 ubi->dev.groups = ubi_dev_groups;
932
933 ubi->mtd = mtd;
934 ubi->ubi_num = ubi_num;
935 ubi->vid_hdr_offset = vid_hdr_offset;
936 ubi->autoresize_vol_id = -1;
937
938 #ifdef CONFIG_MTD_UBI_FASTMAP
939 ubi->fm_pool.used = ubi->fm_pool.size = 0;
940 ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
941
942 /*
943 * fm_pool.max_size is 5% of the total number of PEBs but it's also
944 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
945 */
946 ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
947 ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
948 ubi->fm_pool.max_size = max(ubi->fm_pool.max_size,
949 UBI_FM_MIN_POOL_SIZE);
950
951 ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
952 ubi->fm_disabled = (!fm_autoconvert || disable_fm) ? 1 : 0;
953 if (fm_debug)
954 ubi_enable_dbg_chk_fastmap(ubi);
955
956 if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
957 <= UBI_FM_MAX_START) {
958 ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
959 UBI_FM_MAX_START);
960 ubi->fm_disabled = 1;
961 }
962
963 ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
964 ubi_msg(ubi, "default fastmap WL pool size: %d",
965 ubi->fm_wl_pool.max_size);
966 #else
967 ubi->fm_disabled = 1;
968 #endif
969 mutex_init(&ubi->buf_mutex);
970 mutex_init(&ubi->ckvol_mutex);
971 mutex_init(&ubi->device_mutex);
972 spin_lock_init(&ubi->volumes_lock);
973 init_rwsem(&ubi->fm_protect);
974 init_rwsem(&ubi->fm_eba_sem);
975
976 ubi_msg(ubi, "attaching mtd%d", mtd->index);
977
978 err = io_init(ubi, max_beb_per1024);
979 if (err)
980 goto out_free;
981
982 err = -ENOMEM;
983 ubi->peb_buf = vmalloc(ubi->peb_size);
984 if (!ubi->peb_buf)
985 goto out_free;
986
987 #ifdef CONFIG_MTD_UBI_FASTMAP
988 ubi->fm_size = ubi_calc_fm_size(ubi);
989 ubi->fm_buf = vzalloc(ubi->fm_size);
990 if (!ubi->fm_buf)
991 goto out_free;
992 #endif
993 err = ubi_attach(ubi, disable_fm ? 1 : 0);
994 if (err) {
995 ubi_err(ubi, "failed to attach mtd%d, error %d",
996 mtd->index, err);
997 goto out_free;
998 }
999
1000 if (ubi->autoresize_vol_id != -1) {
1001 err = autoresize(ubi, ubi->autoresize_vol_id);
1002 if (err)
1003 goto out_detach;
1004 }
1005
1006 err = uif_init(ubi);
1007 if (err)
1008 goto out_detach;
1009
1010 err = ubi_debugfs_init_dev(ubi);
1011 if (err)
1012 goto out_uif;
1013
1014 ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
1015 if (IS_ERR(ubi->bgt_thread)) {
1016 err = PTR_ERR(ubi->bgt_thread);
1017 ubi_err(ubi, "cannot spawn \"%s\", error %d",
1018 ubi->bgt_name, err);
1019 goto out_debugfs;
1020 }
1021
1022 ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
1023 mtd->index, mtd->name, ubi->flash_size >> 20);
1024 ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
1025 ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
1026 ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
1027 ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
1028 ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
1029 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
1030 ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
1031 ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
1032 ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
1033 ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
1034 ubi->vtbl_slots);
1035 ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
1036 ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
1037 ubi->image_seq);
1038 ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
1039 ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
1040
1041 /*
1042 * The below lock makes sure we do not race with 'ubi_thread()' which
1043 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1044 */
1045 spin_lock(&ubi->wl_lock);
1046 ubi->thread_enabled = 1;
1047 wake_up_process(ubi->bgt_thread);
1048 spin_unlock(&ubi->wl_lock);
1049
1050 ubi_devices[ubi_num] = ubi;
1051 ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1052 return ubi_num;
1053
1054 out_debugfs:
1055 ubi_debugfs_exit_dev(ubi);
1056 out_uif:
1057 uif_close(ubi);
1058 out_detach:
1059 ubi_wl_close(ubi);
1060 ubi_free_all_volumes(ubi);
1061 vfree(ubi->vtbl);
1062 out_free:
1063 vfree(ubi->peb_buf);
1064 vfree(ubi->fm_buf);
1065 put_device(&ubi->dev);
1066 return err;
1067 }
1068
1069 /**
1070 * ubi_detach_mtd_dev - detach an MTD device.
1071 * @ubi_num: UBI device number to detach from
1072 * @anyway: detach MTD even if device reference count is not zero
1073 *
1074 * This function destroys an UBI device number @ubi_num and detaches the
1075 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1076 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1077 * exist.
1078 *
1079 * Note, the invocations of this function has to be serialized by the
1080 * @ubi_devices_mutex.
1081 */
ubi_detach_mtd_dev(int ubi_num,int anyway)1082 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1083 {
1084 struct ubi_device *ubi;
1085
1086 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1087 return -EINVAL;
1088
1089 ubi = ubi_get_device(ubi_num);
1090 if (!ubi)
1091 return -EINVAL;
1092
1093 spin_lock(&ubi_devices_lock);
1094 put_device(&ubi->dev);
1095 ubi->ref_count -= 1;
1096 if (ubi->ref_count) {
1097 if (!anyway) {
1098 spin_unlock(&ubi_devices_lock);
1099 return -EBUSY;
1100 }
1101 /* This may only happen if there is a bug */
1102 ubi_err(ubi, "%s reference count %d, destroy anyway",
1103 ubi->ubi_name, ubi->ref_count);
1104 }
1105 ubi_devices[ubi_num] = NULL;
1106 spin_unlock(&ubi_devices_lock);
1107
1108 ubi_assert(ubi_num == ubi->ubi_num);
1109 ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1110 ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
1111 #ifdef CONFIG_MTD_UBI_FASTMAP
1112 /* If we don't write a new fastmap at detach time we lose all
1113 * EC updates that have been made since the last written fastmap.
1114 * In case of fastmap debugging we omit the update to simulate an
1115 * unclean shutdown. */
1116 if (!ubi_dbg_chk_fastmap(ubi))
1117 ubi_update_fastmap(ubi);
1118 #endif
1119 /*
1120 * Before freeing anything, we have to stop the background thread to
1121 * prevent it from doing anything on this device while we are freeing.
1122 */
1123 if (ubi->bgt_thread)
1124 kthread_stop(ubi->bgt_thread);
1125
1126 #ifdef CONFIG_MTD_UBI_FASTMAP
1127 cancel_work_sync(&ubi->fm_work);
1128 #endif
1129 ubi_debugfs_exit_dev(ubi);
1130 uif_close(ubi);
1131
1132 ubi_wl_close(ubi);
1133 ubi_free_internal_volumes(ubi);
1134 vfree(ubi->vtbl);
1135 vfree(ubi->peb_buf);
1136 vfree(ubi->fm_buf);
1137 ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1138 put_mtd_device(ubi->mtd);
1139 put_device(&ubi->dev);
1140 return 0;
1141 }
1142
1143 /**
1144 * open_mtd_by_chdev - open an MTD device by its character device node path.
1145 * @mtd_dev: MTD character device node path
1146 *
1147 * This helper function opens an MTD device by its character node device path.
1148 * Returns MTD device description object in case of success and a negative
1149 * error code in case of failure.
1150 */
open_mtd_by_chdev(const char * mtd_dev)1151 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1152 {
1153 int err, minor;
1154 struct path path;
1155 struct kstat stat;
1156
1157 /* Probably this is an MTD character device node path */
1158 err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1159 if (err)
1160 return ERR_PTR(err);
1161
1162 err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
1163 path_put(&path);
1164 if (err)
1165 return ERR_PTR(err);
1166
1167 /* MTD device number is defined by the major / minor numbers */
1168 if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))
1169 return ERR_PTR(-EINVAL);
1170
1171 minor = MINOR(stat.rdev);
1172
1173 if (minor & 1)
1174 /*
1175 * Just do not think the "/dev/mtdrX" devices support is need,
1176 * so do not support them to avoid doing extra work.
1177 */
1178 return ERR_PTR(-EINVAL);
1179
1180 return get_mtd_device(NULL, minor / 2);
1181 }
1182
1183 /**
1184 * open_mtd_device - open MTD device by name, character device path, or number.
1185 * @mtd_dev: name, character device node path, or MTD device device number
1186 *
1187 * This function tries to open and MTD device described by @mtd_dev string,
1188 * which is first treated as ASCII MTD device number, and if it is not true, it
1189 * is treated as MTD device name, and if that is also not true, it is treated
1190 * as MTD character device node path. Returns MTD device description object in
1191 * case of success and a negative error code in case of failure.
1192 */
open_mtd_device(const char * mtd_dev)1193 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1194 {
1195 struct mtd_info *mtd;
1196 int mtd_num;
1197 char *endp;
1198
1199 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1200 if (*endp != '\0' || mtd_dev == endp) {
1201 /*
1202 * This does not look like an ASCII integer, probably this is
1203 * MTD device name.
1204 */
1205 mtd = get_mtd_device_nm(mtd_dev);
1206 if (PTR_ERR(mtd) == -ENODEV)
1207 /* Probably this is an MTD character device node path */
1208 mtd = open_mtd_by_chdev(mtd_dev);
1209 } else
1210 mtd = get_mtd_device(NULL, mtd_num);
1211
1212 return mtd;
1213 }
1214
ubi_init(void)1215 static int __init ubi_init(void)
1216 {
1217 int err, i, k;
1218
1219 /* Ensure that EC and VID headers have correct size */
1220 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1221 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1222
1223 if (mtd_devs > UBI_MAX_DEVICES) {
1224 pr_err("UBI error: too many MTD devices, maximum is %d\n",
1225 UBI_MAX_DEVICES);
1226 return -EINVAL;
1227 }
1228
1229 /* Create base sysfs directory and sysfs files */
1230 err = class_register(&ubi_class);
1231 if (err < 0)
1232 return err;
1233
1234 err = misc_register(&ubi_ctrl_cdev);
1235 if (err) {
1236 pr_err("UBI error: cannot register device\n");
1237 goto out;
1238 }
1239
1240 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1241 sizeof(struct ubi_wl_entry),
1242 0, 0, NULL);
1243 if (!ubi_wl_entry_slab) {
1244 err = -ENOMEM;
1245 goto out_dev_unreg;
1246 }
1247
1248 err = ubi_debugfs_init();
1249 if (err)
1250 goto out_slab;
1251
1252
1253 /* Attach MTD devices */
1254 for (i = 0; i < mtd_devs; i++) {
1255 struct mtd_dev_param *p = &mtd_dev_param[i];
1256 struct mtd_info *mtd;
1257
1258 cond_resched();
1259
1260 mtd = open_mtd_device(p->name);
1261 if (IS_ERR(mtd)) {
1262 err = PTR_ERR(mtd);
1263 pr_err("UBI error: cannot open mtd %s, error %d\n",
1264 p->name, err);
1265 /* See comment below re-ubi_is_module(). */
1266 if (ubi_is_module())
1267 goto out_detach;
1268 continue;
1269 }
1270
1271 mutex_lock(&ubi_devices_mutex);
1272 err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1273 p->vid_hdr_offs, p->max_beb_per1024,
1274 false);
1275 mutex_unlock(&ubi_devices_mutex);
1276 if (err < 0) {
1277 pr_err("UBI error: cannot attach mtd%d\n",
1278 mtd->index);
1279 put_mtd_device(mtd);
1280
1281 /*
1282 * Originally UBI stopped initializing on any error.
1283 * However, later on it was found out that this
1284 * behavior is not very good when UBI is compiled into
1285 * the kernel and the MTD devices to attach are passed
1286 * through the command line. Indeed, UBI failure
1287 * stopped whole boot sequence.
1288 *
1289 * To fix this, we changed the behavior for the
1290 * non-module case, but preserved the old behavior for
1291 * the module case, just for compatibility. This is a
1292 * little inconsistent, though.
1293 */
1294 if (ubi_is_module())
1295 goto out_detach;
1296 }
1297 }
1298
1299 err = ubiblock_init();
1300 if (err) {
1301 pr_err("UBI error: block: cannot initialize, error %d\n", err);
1302
1303 /* See comment above re-ubi_is_module(). */
1304 if (ubi_is_module())
1305 goto out_detach;
1306 }
1307
1308 return 0;
1309
1310 out_detach:
1311 for (k = 0; k < i; k++)
1312 if (ubi_devices[k]) {
1313 mutex_lock(&ubi_devices_mutex);
1314 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1315 mutex_unlock(&ubi_devices_mutex);
1316 }
1317 ubi_debugfs_exit();
1318 out_slab:
1319 kmem_cache_destroy(ubi_wl_entry_slab);
1320 out_dev_unreg:
1321 misc_deregister(&ubi_ctrl_cdev);
1322 out:
1323 class_unregister(&ubi_class);
1324 pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1325 return err;
1326 }
1327 late_initcall(ubi_init);
1328
ubi_exit(void)1329 static void __exit ubi_exit(void)
1330 {
1331 int i;
1332
1333 ubiblock_exit();
1334
1335 for (i = 0; i < UBI_MAX_DEVICES; i++)
1336 if (ubi_devices[i]) {
1337 mutex_lock(&ubi_devices_mutex);
1338 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1339 mutex_unlock(&ubi_devices_mutex);
1340 }
1341 ubi_debugfs_exit();
1342 kmem_cache_destroy(ubi_wl_entry_slab);
1343 misc_deregister(&ubi_ctrl_cdev);
1344 class_unregister(&ubi_class);
1345 }
1346 module_exit(ubi_exit);
1347
1348 /**
1349 * bytes_str_to_int - convert a number of bytes string into an integer.
1350 * @str: the string to convert
1351 *
1352 * This function returns positive resulting integer in case of success and a
1353 * negative error code in case of failure.
1354 */
bytes_str_to_int(const char * str)1355 static int bytes_str_to_int(const char *str)
1356 {
1357 char *endp;
1358 unsigned long result;
1359
1360 result = simple_strtoul(str, &endp, 0);
1361 if (str == endp || result >= INT_MAX) {
1362 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1363 return -EINVAL;
1364 }
1365
1366 switch (*endp) {
1367 case 'G':
1368 result *= 1024;
1369 fallthrough;
1370 case 'M':
1371 result *= 1024;
1372 fallthrough;
1373 case 'K':
1374 result *= 1024;
1375 break;
1376 case '\0':
1377 break;
1378 default:
1379 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1380 return -EINVAL;
1381 }
1382
1383 return result;
1384 }
1385
1386 /**
1387 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1388 * @val: the parameter value to parse
1389 * @kp: not used
1390 *
1391 * This function returns zero in case of success and a negative error code in
1392 * case of error.
1393 */
ubi_mtd_param_parse(const char * val,const struct kernel_param * kp)1394 static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp)
1395 {
1396 int i, len;
1397 struct mtd_dev_param *p;
1398 char buf[MTD_PARAM_LEN_MAX];
1399 char *pbuf = &buf[0];
1400 char *tokens[MTD_PARAM_MAX_COUNT], *token;
1401
1402 if (!val)
1403 return -EINVAL;
1404
1405 if (mtd_devs == UBI_MAX_DEVICES) {
1406 pr_err("UBI error: too many parameters, max. is %d\n",
1407 UBI_MAX_DEVICES);
1408 return -EINVAL;
1409 }
1410
1411 len = strnlen(val, MTD_PARAM_LEN_MAX);
1412 if (len == MTD_PARAM_LEN_MAX) {
1413 pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1414 val, MTD_PARAM_LEN_MAX);
1415 return -EINVAL;
1416 }
1417
1418 if (len == 0) {
1419 pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1420 return 0;
1421 }
1422
1423 strcpy(buf, val);
1424
1425 /* Get rid of the final newline */
1426 if (buf[len - 1] == '\n')
1427 buf[len - 1] = '\0';
1428
1429 for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1430 tokens[i] = strsep(&pbuf, ",");
1431
1432 if (pbuf) {
1433 pr_err("UBI error: too many arguments at \"%s\"\n", val);
1434 return -EINVAL;
1435 }
1436
1437 p = &mtd_dev_param[mtd_devs];
1438 strcpy(&p->name[0], tokens[0]);
1439
1440 token = tokens[1];
1441 if (token) {
1442 p->vid_hdr_offs = bytes_str_to_int(token);
1443
1444 if (p->vid_hdr_offs < 0)
1445 return p->vid_hdr_offs;
1446 }
1447
1448 token = tokens[2];
1449 if (token) {
1450 int err = kstrtoint(token, 10, &p->max_beb_per1024);
1451
1452 if (err) {
1453 pr_err("UBI error: bad value for max_beb_per1024 parameter: %s",
1454 token);
1455 return -EINVAL;
1456 }
1457 }
1458
1459 token = tokens[3];
1460 if (token) {
1461 int err = kstrtoint(token, 10, &p->ubi_num);
1462
1463 if (err) {
1464 pr_err("UBI error: bad value for ubi_num parameter: %s",
1465 token);
1466 return -EINVAL;
1467 }
1468 } else
1469 p->ubi_num = UBI_DEV_NUM_AUTO;
1470
1471 mtd_devs += 1;
1472 return 0;
1473 }
1474
1475 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 0400);
1476 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1477 "Multiple \"mtd\" parameters may be specified.\n"
1478 "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1479 "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1480 "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1481 __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1482 "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1483 "\n"
1484 "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1485 "Example 2: mtd=content,1984 mtd=4 - attach MTD device with name \"content\" using VID header offset 1984, and MTD device number 4 with default VID header offset.\n"
1486 "Example 3: mtd=/dev/mtd1,0,25 - attach MTD device /dev/mtd1 using default VID header offset and reserve 25*nand_size_in_blocks/1024 erase blocks for bad block handling.\n"
1487 "Example 4: mtd=/dev/mtd1,0,0,5 - attach MTD device /dev/mtd1 to UBI 5 and using default values for the other fields.\n"
1488 "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1489 #ifdef CONFIG_MTD_UBI_FASTMAP
1490 module_param(fm_autoconvert, bool, 0644);
1491 MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1492 module_param(fm_debug, bool, 0);
1493 MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1494 #endif
1495 MODULE_VERSION(__stringify(UBI_VERSION));
1496 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1497 MODULE_AUTHOR("Artem Bityutskiy");
1498 MODULE_LICENSE("GPL");
1499