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 5
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 * @enable_fm: enable fastmap when value is non-zero
57 */
58 struct mtd_dev_param {
59 char name[MTD_PARAM_LEN_MAX];
60 int ubi_num;
61 int vid_hdr_offs;
62 int max_beb_per1024;
63 int enable_fm;
64 };
65
66 /* Numbers of elements set in the @mtd_dev_param array */
67 static int mtd_devs;
68
69 /* MTD devices specification parameters */
70 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
71 #ifdef CONFIG_MTD_UBI_FASTMAP
72 /* UBI module parameter to enable fastmap automatically on non-fastmap images */
73 static bool fm_autoconvert;
74 static bool fm_debug;
75 #endif
76
77 /* Slab cache for wear-leveling entries */
78 struct kmem_cache *ubi_wl_entry_slab;
79
80 /* UBI control character device */
81 static struct miscdevice ubi_ctrl_cdev = {
82 .minor = MISC_DYNAMIC_MINOR,
83 .name = "ubi_ctrl",
84 .fops = &ubi_ctrl_cdev_operations,
85 };
86
87 /* All UBI devices in system */
88 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
89
90 /* Serializes UBI devices creations and removals */
91 DEFINE_MUTEX(ubi_devices_mutex);
92
93 /* Protects @ubi_devices and @ubi->ref_count */
94 static DEFINE_SPINLOCK(ubi_devices_lock);
95
96 /* "Show" method for files in '/<sysfs>/class/ubi/' */
97 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
version_show(const struct class * class,const struct class_attribute * attr,char * buf)98 static ssize_t version_show(const struct class *class, const struct class_attribute *attr,
99 char *buf)
100 {
101 return sprintf(buf, "%d\n", UBI_VERSION);
102 }
103 static CLASS_ATTR_RO(version);
104
105 static struct attribute *ubi_class_attrs[] = {
106 &class_attr_version.attr,
107 NULL,
108 };
109 ATTRIBUTE_GROUPS(ubi_class);
110
111 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
112 struct class ubi_class = {
113 .name = UBI_NAME_STR,
114 .class_groups = ubi_class_groups,
115 };
116
117 static ssize_t dev_attribute_show(struct device *dev,
118 struct device_attribute *attr, char *buf);
119
120 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
121 static struct device_attribute dev_eraseblock_size =
122 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
123 static struct device_attribute dev_avail_eraseblocks =
124 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
125 static struct device_attribute dev_total_eraseblocks =
126 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
127 static struct device_attribute dev_volumes_count =
128 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
129 static struct device_attribute dev_max_ec =
130 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
131 static struct device_attribute dev_reserved_for_bad =
132 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
133 static struct device_attribute dev_bad_peb_count =
134 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
135 static struct device_attribute dev_max_vol_count =
136 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
137 static struct device_attribute dev_min_io_size =
138 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
139 static struct device_attribute dev_bgt_enabled =
140 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
141 static struct device_attribute dev_mtd_num =
142 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
143 static struct device_attribute dev_ro_mode =
144 __ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
145
146 /**
147 * ubi_volume_notify - send a volume change notification.
148 * @ubi: UBI device description object
149 * @vol: volume description object of the changed volume
150 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
151 *
152 * This is a helper function which notifies all subscribers about a volume
153 * change event (creation, removal, re-sizing, re-naming, updating). Returns
154 * zero in case of success and a negative error code in case of failure.
155 */
ubi_volume_notify(struct ubi_device * ubi,struct ubi_volume * vol,int ntype)156 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
157 {
158 int ret;
159 struct ubi_notification nt;
160
161 ubi_do_get_device_info(ubi, &nt.di);
162 ubi_do_get_volume_info(ubi, vol, &nt.vi);
163
164 switch (ntype) {
165 case UBI_VOLUME_ADDED:
166 case UBI_VOLUME_REMOVED:
167 case UBI_VOLUME_RESIZED:
168 case UBI_VOLUME_RENAMED:
169 ret = ubi_update_fastmap(ubi);
170 if (ret)
171 ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
172 }
173
174 return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
175 }
176
177 /**
178 * ubi_notify_all - send a notification to all volumes.
179 * @ubi: UBI device description object
180 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
181 * @nb: the notifier to call
182 *
183 * This function walks all volumes of UBI device @ubi and sends the @ntype
184 * notification for each volume. If @nb is %NULL, then all registered notifiers
185 * are called, otherwise only the @nb notifier is called. Returns the number of
186 * sent notifications.
187 */
ubi_notify_all(struct ubi_device * ubi,int ntype,struct notifier_block * nb)188 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
189 {
190 struct ubi_notification nt;
191 int i, count = 0;
192
193 ubi_do_get_device_info(ubi, &nt.di);
194
195 mutex_lock(&ubi->device_mutex);
196 for (i = 0; i < ubi->vtbl_slots; i++) {
197 /*
198 * Since the @ubi->device is locked, and we are not going to
199 * change @ubi->volumes, we do not have to lock
200 * @ubi->volumes_lock.
201 */
202 if (!ubi->volumes[i])
203 continue;
204
205 ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
206 if (nb)
207 nb->notifier_call(nb, ntype, &nt);
208 else
209 blocking_notifier_call_chain(&ubi_notifiers, ntype,
210 &nt);
211 count += 1;
212 }
213 mutex_unlock(&ubi->device_mutex);
214
215 return count;
216 }
217
218 /**
219 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
220 * @nb: the notifier to call
221 *
222 * This function walks all UBI devices and volumes and sends the
223 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
224 * registered notifiers are called, otherwise only the @nb notifier is called.
225 * Returns the number of sent notifications.
226 */
ubi_enumerate_volumes(struct notifier_block * nb)227 int ubi_enumerate_volumes(struct notifier_block *nb)
228 {
229 int i, count = 0;
230
231 /*
232 * Since the @ubi_devices_mutex is locked, and we are not going to
233 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
234 */
235 for (i = 0; i < UBI_MAX_DEVICES; i++) {
236 struct ubi_device *ubi = ubi_devices[i];
237
238 if (!ubi)
239 continue;
240 count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
241 }
242
243 return count;
244 }
245
246 /**
247 * ubi_get_device - get UBI device.
248 * @ubi_num: UBI device number
249 *
250 * This function returns UBI device description object for UBI device number
251 * @ubi_num, or %NULL if the device does not exist. This function increases the
252 * device reference count to prevent removal of the device. In other words, the
253 * device cannot be removed if its reference count is not zero.
254 */
ubi_get_device(int ubi_num)255 struct ubi_device *ubi_get_device(int ubi_num)
256 {
257 struct ubi_device *ubi;
258
259 spin_lock(&ubi_devices_lock);
260 ubi = ubi_devices[ubi_num];
261 if (ubi) {
262 ubi_assert(ubi->ref_count >= 0);
263 ubi->ref_count += 1;
264 get_device(&ubi->dev);
265 }
266 spin_unlock(&ubi_devices_lock);
267
268 return ubi;
269 }
270
271 /**
272 * ubi_put_device - drop an UBI device reference.
273 * @ubi: UBI device description object
274 */
ubi_put_device(struct ubi_device * ubi)275 void ubi_put_device(struct ubi_device *ubi)
276 {
277 spin_lock(&ubi_devices_lock);
278 ubi->ref_count -= 1;
279 put_device(&ubi->dev);
280 spin_unlock(&ubi_devices_lock);
281 }
282
283 /**
284 * ubi_get_by_major - get UBI device by character device major number.
285 * @major: major number
286 *
287 * This function is similar to 'ubi_get_device()', but it searches the device
288 * by its major number.
289 */
ubi_get_by_major(int major)290 struct ubi_device *ubi_get_by_major(int major)
291 {
292 int i;
293 struct ubi_device *ubi;
294
295 spin_lock(&ubi_devices_lock);
296 for (i = 0; i < UBI_MAX_DEVICES; i++) {
297 ubi = ubi_devices[i];
298 if (ubi && MAJOR(ubi->cdev.dev) == major) {
299 ubi_assert(ubi->ref_count >= 0);
300 ubi->ref_count += 1;
301 get_device(&ubi->dev);
302 spin_unlock(&ubi_devices_lock);
303 return ubi;
304 }
305 }
306 spin_unlock(&ubi_devices_lock);
307
308 return NULL;
309 }
310
311 /**
312 * ubi_major2num - get UBI device number by character device major number.
313 * @major: major number
314 *
315 * This function searches UBI device number object by its major number. If UBI
316 * device was not found, this function returns -ENODEV, otherwise the UBI device
317 * number is returned.
318 */
ubi_major2num(int major)319 int ubi_major2num(int major)
320 {
321 int i, ubi_num = -ENODEV;
322
323 spin_lock(&ubi_devices_lock);
324 for (i = 0; i < UBI_MAX_DEVICES; i++) {
325 struct ubi_device *ubi = ubi_devices[i];
326
327 if (ubi && MAJOR(ubi->cdev.dev) == major) {
328 ubi_num = ubi->ubi_num;
329 break;
330 }
331 }
332 spin_unlock(&ubi_devices_lock);
333
334 return ubi_num;
335 }
336
337 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
dev_attribute_show(struct device * dev,struct device_attribute * attr,char * buf)338 static ssize_t dev_attribute_show(struct device *dev,
339 struct device_attribute *attr, char *buf)
340 {
341 ssize_t ret;
342 struct ubi_device *ubi;
343
344 /*
345 * The below code looks weird, but it actually makes sense. We get the
346 * UBI device reference from the contained 'struct ubi_device'. But it
347 * is unclear if the device was removed or not yet. Indeed, if the
348 * device was removed before we increased its reference count,
349 * 'ubi_get_device()' will return -ENODEV and we fail.
350 *
351 * Remember, 'struct ubi_device' is freed in the release function, so
352 * we still can use 'ubi->ubi_num'.
353 */
354 ubi = container_of(dev, struct ubi_device, dev);
355
356 if (attr == &dev_eraseblock_size)
357 ret = sprintf(buf, "%d\n", ubi->leb_size);
358 else if (attr == &dev_avail_eraseblocks)
359 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
360 else if (attr == &dev_total_eraseblocks)
361 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
362 else if (attr == &dev_volumes_count)
363 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
364 else if (attr == &dev_max_ec)
365 ret = sprintf(buf, "%d\n", ubi->max_ec);
366 else if (attr == &dev_reserved_for_bad)
367 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
368 else if (attr == &dev_bad_peb_count)
369 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
370 else if (attr == &dev_max_vol_count)
371 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
372 else if (attr == &dev_min_io_size)
373 ret = sprintf(buf, "%d\n", ubi->min_io_size);
374 else if (attr == &dev_bgt_enabled)
375 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
376 else if (attr == &dev_mtd_num)
377 ret = sprintf(buf, "%d\n", ubi->mtd->index);
378 else if (attr == &dev_ro_mode)
379 ret = sprintf(buf, "%d\n", ubi->ro_mode);
380 else
381 ret = -EINVAL;
382
383 return ret;
384 }
385
386 static struct attribute *ubi_dev_attrs[] = {
387 &dev_eraseblock_size.attr,
388 &dev_avail_eraseblocks.attr,
389 &dev_total_eraseblocks.attr,
390 &dev_volumes_count.attr,
391 &dev_max_ec.attr,
392 &dev_reserved_for_bad.attr,
393 &dev_bad_peb_count.attr,
394 &dev_max_vol_count.attr,
395 &dev_min_io_size.attr,
396 &dev_bgt_enabled.attr,
397 &dev_mtd_num.attr,
398 &dev_ro_mode.attr,
399 NULL
400 };
401 ATTRIBUTE_GROUPS(ubi_dev);
402
dev_release(struct device * dev)403 static void dev_release(struct device *dev)
404 {
405 struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
406
407 kfree(ubi);
408 }
409
410 /**
411 * kill_volumes - destroy all user volumes.
412 * @ubi: UBI device description object
413 */
kill_volumes(struct ubi_device * ubi)414 static void kill_volumes(struct ubi_device *ubi)
415 {
416 int i;
417
418 for (i = 0; i < ubi->vtbl_slots; i++)
419 if (ubi->volumes[i])
420 ubi_free_volume(ubi, ubi->volumes[i]);
421 }
422
423 /**
424 * uif_init - initialize user interfaces for an UBI device.
425 * @ubi: UBI device description object
426 *
427 * This function initializes various user interfaces for an UBI device. If the
428 * initialization fails at an early stage, this function frees all the
429 * resources it allocated, returns an error.
430 *
431 * This function returns zero in case of success and a negative error code in
432 * case of failure.
433 */
uif_init(struct ubi_device * ubi)434 static int uif_init(struct ubi_device *ubi)
435 {
436 int i, err;
437 dev_t dev;
438
439 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
440
441 /*
442 * Major numbers for the UBI character devices are allocated
443 * dynamically. Major numbers of volume character devices are
444 * equivalent to ones of the corresponding UBI character device. Minor
445 * numbers of UBI character devices are 0, while minor numbers of
446 * volume character devices start from 1. Thus, we allocate one major
447 * number and ubi->vtbl_slots + 1 minor numbers.
448 */
449 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
450 if (err) {
451 ubi_err(ubi, "cannot register UBI character devices");
452 return err;
453 }
454
455 ubi->dev.devt = dev;
456
457 ubi_assert(MINOR(dev) == 0);
458 cdev_init(&ubi->cdev, &ubi_cdev_operations);
459 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
460 ubi->cdev.owner = THIS_MODULE;
461
462 dev_set_name(&ubi->dev, UBI_NAME_STR "%d", ubi->ubi_num);
463 err = cdev_device_add(&ubi->cdev, &ubi->dev);
464 if (err)
465 goto out_unreg;
466
467 for (i = 0; i < ubi->vtbl_slots; i++)
468 if (ubi->volumes[i]) {
469 err = ubi_add_volume(ubi, ubi->volumes[i]);
470 if (err) {
471 ubi_err(ubi, "cannot add volume %d", i);
472 ubi->volumes[i] = NULL;
473 goto out_volumes;
474 }
475 }
476
477 return 0;
478
479 out_volumes:
480 kill_volumes(ubi);
481 cdev_device_del(&ubi->cdev, &ubi->dev);
482 out_unreg:
483 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
484 ubi_err(ubi, "cannot initialize UBI %s, error %d",
485 ubi->ubi_name, err);
486 return err;
487 }
488
489 /**
490 * uif_close - close user interfaces for an UBI device.
491 * @ubi: UBI device description object
492 *
493 * Note, since this function un-registers UBI volume device objects (@vol->dev),
494 * the memory allocated voe the volumes is freed as well (in the release
495 * function).
496 */
uif_close(struct ubi_device * ubi)497 static void uif_close(struct ubi_device *ubi)
498 {
499 kill_volumes(ubi);
500 cdev_device_del(&ubi->cdev, &ubi->dev);
501 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
502 }
503
504 /**
505 * ubi_free_volumes_from - free volumes from specific index.
506 * @ubi: UBI device description object
507 * @from: the start index used for volume free.
508 */
ubi_free_volumes_from(struct ubi_device * ubi,int from)509 static void ubi_free_volumes_from(struct ubi_device *ubi, int from)
510 {
511 int i;
512
513 for (i = from; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
514 if (!ubi->volumes[i])
515 continue;
516 ubi_eba_replace_table(ubi->volumes[i], NULL);
517 ubi_fastmap_destroy_checkmap(ubi->volumes[i]);
518 kfree(ubi->volumes[i]);
519 ubi->volumes[i] = NULL;
520 }
521 }
522
523 /**
524 * ubi_free_all_volumes - free all volumes.
525 * @ubi: UBI device description object
526 */
ubi_free_all_volumes(struct ubi_device * ubi)527 void ubi_free_all_volumes(struct ubi_device *ubi)
528 {
529 ubi_free_volumes_from(ubi, 0);
530 }
531
532 /**
533 * ubi_free_internal_volumes - free internal volumes.
534 * @ubi: UBI device description object
535 */
ubi_free_internal_volumes(struct ubi_device * ubi)536 void ubi_free_internal_volumes(struct ubi_device *ubi)
537 {
538 ubi_free_volumes_from(ubi, ubi->vtbl_slots);
539 }
540
get_bad_peb_limit(const struct ubi_device * ubi,int max_beb_per1024)541 static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
542 {
543 int limit, device_pebs;
544 uint64_t device_size;
545
546 if (!max_beb_per1024) {
547 /*
548 * Since max_beb_per1024 has not been set by the user in either
549 * the cmdline or Kconfig, use mtd_max_bad_blocks to set the
550 * limit if it is supported by the device.
551 */
552 limit = mtd_max_bad_blocks(ubi->mtd, 0, ubi->mtd->size);
553 if (limit < 0)
554 return 0;
555 return limit;
556 }
557
558 /*
559 * Here we are using size of the entire flash chip and
560 * not just the MTD partition size because the maximum
561 * number of bad eraseblocks is a percentage of the
562 * whole device and bad eraseblocks are not fairly
563 * distributed over the flash chip. So the worst case
564 * is that all the bad eraseblocks of the chip are in
565 * the MTD partition we are attaching (ubi->mtd).
566 */
567 device_size = mtd_get_device_size(ubi->mtd);
568 device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
569 limit = mult_frac(device_pebs, max_beb_per1024, 1024);
570
571 /* Round it up */
572 if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
573 limit += 1;
574
575 return limit;
576 }
577
578 /**
579 * io_init - initialize I/O sub-system for a given UBI device.
580 * @ubi: UBI device description object
581 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
582 *
583 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
584 * assumed:
585 * o EC header is always at offset zero - this cannot be changed;
586 * o VID header starts just after the EC header at the closest address
587 * aligned to @io->hdrs_min_io_size;
588 * o data starts just after the VID header at the closest address aligned to
589 * @io->min_io_size
590 *
591 * This function returns zero in case of success and a negative error code in
592 * case of failure.
593 */
io_init(struct ubi_device * ubi,int max_beb_per1024)594 static int io_init(struct ubi_device *ubi, int max_beb_per1024)
595 {
596 dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
597 dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
598
599 if (ubi->mtd->numeraseregions != 0) {
600 /*
601 * Some flashes have several erase regions. Different regions
602 * may have different eraseblock size and other
603 * characteristics. It looks like mostly multi-region flashes
604 * have one "main" region and one or more small regions to
605 * store boot loader code or boot parameters or whatever. I
606 * guess we should just pick the largest region. But this is
607 * not implemented.
608 */
609 ubi_err(ubi, "multiple regions, not implemented");
610 return -EINVAL;
611 }
612
613 if (ubi->vid_hdr_offset < 0)
614 return -EINVAL;
615
616 /*
617 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
618 * physical eraseblocks maximum.
619 */
620
621 ubi->peb_size = ubi->mtd->erasesize;
622 ubi->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
623 ubi->flash_size = ubi->mtd->size;
624
625 if (mtd_can_have_bb(ubi->mtd)) {
626 ubi->bad_allowed = 1;
627 ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
628 }
629
630 if (ubi->mtd->type == MTD_NORFLASH)
631 ubi->nor_flash = 1;
632
633 ubi->min_io_size = ubi->mtd->writesize;
634 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
635
636 /*
637 * Make sure minimal I/O unit is power of 2. Note, there is no
638 * fundamental reason for this assumption. It is just an optimization
639 * which allows us to avoid costly division operations.
640 */
641 if (!is_power_of_2(ubi->min_io_size)) {
642 ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
643 ubi->min_io_size);
644 return -EINVAL;
645 }
646
647 ubi_assert(ubi->hdrs_min_io_size > 0);
648 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
649 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
650
651 ubi->max_write_size = ubi->mtd->writebufsize;
652 /*
653 * Maximum write size has to be greater or equivalent to min. I/O
654 * size, and be multiple of min. I/O size.
655 */
656 if (ubi->max_write_size < ubi->min_io_size ||
657 ubi->max_write_size % ubi->min_io_size ||
658 !is_power_of_2(ubi->max_write_size)) {
659 ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
660 ubi->max_write_size, ubi->min_io_size);
661 return -EINVAL;
662 }
663
664 /* Calculate default aligned sizes of EC and VID headers */
665 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
666 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
667
668 dbg_gen("min_io_size %d", ubi->min_io_size);
669 dbg_gen("max_write_size %d", ubi->max_write_size);
670 dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
671 dbg_gen("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
672 dbg_gen("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
673
674 if (ubi->vid_hdr_offset == 0)
675 /* Default offset */
676 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
677 ubi->ec_hdr_alsize;
678 else {
679 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
680 ~(ubi->hdrs_min_io_size - 1);
681 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
682 ubi->vid_hdr_aloffset;
683 }
684
685 /*
686 * Memory allocation for VID header is ubi->vid_hdr_alsize
687 * which is described in comments in io.c.
688 * Make sure VID header shift + UBI_VID_HDR_SIZE not exceeds
689 * ubi->vid_hdr_alsize, so that all vid header operations
690 * won't access memory out of bounds.
691 */
692 if ((ubi->vid_hdr_shift + UBI_VID_HDR_SIZE) > ubi->vid_hdr_alsize) {
693 ubi_err(ubi, "Invalid VID header offset %d, VID header shift(%d)"
694 " + VID header size(%zu) > VID header aligned size(%d).",
695 ubi->vid_hdr_offset, ubi->vid_hdr_shift,
696 UBI_VID_HDR_SIZE, ubi->vid_hdr_alsize);
697 return -EINVAL;
698 }
699
700 /* Similar for the data offset */
701 ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
702 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
703
704 dbg_gen("vid_hdr_offset %d", ubi->vid_hdr_offset);
705 dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
706 dbg_gen("vid_hdr_shift %d", ubi->vid_hdr_shift);
707 dbg_gen("leb_start %d", ubi->leb_start);
708
709 /* The shift must be aligned to 32-bit boundary */
710 if (ubi->vid_hdr_shift % 4) {
711 ubi_err(ubi, "unaligned VID header shift %d",
712 ubi->vid_hdr_shift);
713 return -EINVAL;
714 }
715
716 /* Check sanity */
717 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
718 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
719 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
720 ubi->leb_start & (ubi->min_io_size - 1)) {
721 ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
722 ubi->vid_hdr_offset, ubi->leb_start);
723 return -EINVAL;
724 }
725
726 /*
727 * Set maximum amount of physical erroneous eraseblocks to be 10%.
728 * Erroneous PEB are those which have read errors.
729 */
730 ubi->max_erroneous = ubi->peb_count / 10;
731 if (ubi->max_erroneous < 16)
732 ubi->max_erroneous = 16;
733 dbg_gen("max_erroneous %d", ubi->max_erroneous);
734
735 /*
736 * It may happen that EC and VID headers are situated in one minimal
737 * I/O unit. In this case we can only accept this UBI image in
738 * read-only mode.
739 */
740 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
741 ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
742 ubi->ro_mode = 1;
743 }
744
745 ubi->leb_size = ubi->peb_size - ubi->leb_start;
746
747 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
748 ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
749 ubi->mtd->index);
750 ubi->ro_mode = 1;
751 }
752
753 /*
754 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
755 * unfortunately, MTD does not provide this information. We should loop
756 * over all physical eraseblocks and invoke mtd->block_is_bad() for
757 * each physical eraseblock. So, we leave @ubi->bad_peb_count
758 * uninitialized so far.
759 */
760
761 return 0;
762 }
763
764 /**
765 * autoresize - re-size the volume which has the "auto-resize" flag set.
766 * @ubi: UBI device description object
767 * @vol_id: ID of the volume to re-size
768 *
769 * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
770 * the volume table to the largest possible size. See comments in ubi-header.h
771 * for more description of the flag. Returns zero in case of success and a
772 * negative error code in case of failure.
773 */
autoresize(struct ubi_device * ubi,int vol_id)774 static int autoresize(struct ubi_device *ubi, int vol_id)
775 {
776 struct ubi_volume_desc desc;
777 struct ubi_volume *vol = ubi->volumes[vol_id];
778 int err, old_reserved_pebs = vol->reserved_pebs;
779
780 if (ubi->ro_mode) {
781 ubi_warn(ubi, "skip auto-resize because of R/O mode");
782 return 0;
783 }
784
785 /*
786 * Clear the auto-resize flag in the volume in-memory copy of the
787 * volume table, and 'ubi_resize_volume()' will propagate this change
788 * to the flash.
789 */
790 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
791
792 if (ubi->avail_pebs == 0) {
793 struct ubi_vtbl_record vtbl_rec;
794
795 /*
796 * No available PEBs to re-size the volume, clear the flag on
797 * flash and exit.
798 */
799 vtbl_rec = ubi->vtbl[vol_id];
800 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
801 if (err)
802 ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
803 vol_id);
804 } else {
805 desc.vol = vol;
806 err = ubi_resize_volume(&desc,
807 old_reserved_pebs + ubi->avail_pebs);
808 if (err)
809 ubi_err(ubi, "cannot auto-resize volume %d",
810 vol_id);
811 }
812
813 if (err)
814 return err;
815
816 ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
817 vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
818 return 0;
819 }
820
821 /**
822 * ubi_attach_mtd_dev - attach an MTD device.
823 * @mtd: MTD device description object
824 * @ubi_num: number to assign to the new UBI device
825 * @vid_hdr_offset: VID header offset
826 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
827 * @disable_fm: whether disable fastmap
828 *
829 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
830 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
831 * which case this function finds a vacant device number and assigns it
832 * automatically. Returns the new UBI device number in case of success and a
833 * negative error code in case of failure.
834 *
835 * If @disable_fm is true, ubi doesn't create new fastmap even the module param
836 * 'fm_autoconvert' is set, and existed old fastmap will be destroyed after
837 * doing full scanning.
838 *
839 * Note, the invocations of this function has to be serialized by the
840 * @ubi_devices_mutex.
841 */
ubi_attach_mtd_dev(struct mtd_info * mtd,int ubi_num,int vid_hdr_offset,int max_beb_per1024,bool disable_fm)842 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
843 int vid_hdr_offset, int max_beb_per1024, bool disable_fm)
844 {
845 struct ubi_device *ubi;
846 int i, err;
847
848 if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
849 return -EINVAL;
850
851 if (!max_beb_per1024)
852 max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
853
854 /*
855 * Check if we already have the same MTD device attached.
856 *
857 * Note, this function assumes that UBI devices creations and deletions
858 * are serialized, so it does not take the &ubi_devices_lock.
859 */
860 for (i = 0; i < UBI_MAX_DEVICES; i++) {
861 ubi = ubi_devices[i];
862 if (ubi && mtd->index == ubi->mtd->index) {
863 pr_err("ubi: mtd%d is already attached to ubi%d\n",
864 mtd->index, i);
865 return -EEXIST;
866 }
867 }
868
869 /*
870 * Make sure this MTD device is not emulated on top of an UBI volume
871 * already. Well, generally this recursion works fine, but there are
872 * different problems like the UBI module takes a reference to itself
873 * by attaching (and thus, opening) the emulated MTD device. This
874 * results in inability to unload the module. And in general it makes
875 * no sense to attach emulated MTD devices, so we prohibit this.
876 */
877 if (mtd->type == MTD_UBIVOLUME) {
878 pr_err("ubi: refuse attaching mtd%d - it is already emulated on top of UBI\n",
879 mtd->index);
880 return -EINVAL;
881 }
882
883 /*
884 * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes.
885 * MLC NAND is different and needs special care, otherwise UBI or UBIFS
886 * will die soon and you will lose all your data.
887 * Relax this rule if the partition we're attaching to operates in SLC
888 * mode.
889 */
890 if (mtd->type == MTD_MLCNANDFLASH &&
891 !(mtd->flags & MTD_SLC_ON_MLC_EMULATION)) {
892 pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n",
893 mtd->index);
894 return -EINVAL;
895 }
896
897 /* UBI cannot work on flashes with zero erasesize. */
898 if (!mtd->erasesize) {
899 pr_err("ubi: refuse attaching mtd%d - zero erasesize flash is not supported\n",
900 mtd->index);
901 return -EINVAL;
902 }
903
904 if (ubi_num == UBI_DEV_NUM_AUTO) {
905 /* Search for an empty slot in the @ubi_devices array */
906 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
907 if (!ubi_devices[ubi_num])
908 break;
909 if (ubi_num == UBI_MAX_DEVICES) {
910 pr_err("ubi: only %d UBI devices may be created\n",
911 UBI_MAX_DEVICES);
912 return -ENFILE;
913 }
914 } else {
915 if (ubi_num >= UBI_MAX_DEVICES)
916 return -EINVAL;
917
918 /* Make sure ubi_num is not busy */
919 if (ubi_devices[ubi_num]) {
920 pr_err("ubi: ubi%i already exists\n", ubi_num);
921 return -EEXIST;
922 }
923 }
924
925 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
926 if (!ubi)
927 return -ENOMEM;
928
929 device_initialize(&ubi->dev);
930 ubi->dev.release = dev_release;
931 ubi->dev.class = &ubi_class;
932 ubi->dev.groups = ubi_dev_groups;
933 ubi->dev.parent = &mtd->dev;
934
935 ubi->mtd = mtd;
936 ubi->ubi_num = ubi_num;
937 ubi->vid_hdr_offset = vid_hdr_offset;
938 ubi->autoresize_vol_id = -1;
939
940 #ifdef CONFIG_MTD_UBI_FASTMAP
941 ubi->fm_pool.used = ubi->fm_pool.size = 0;
942 ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
943
944 /*
945 * fm_pool.max_size is 5% of the total number of PEBs but it's also
946 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
947 */
948 ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
949 ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
950 ubi->fm_pool.max_size = max(ubi->fm_pool.max_size,
951 UBI_FM_MIN_POOL_SIZE);
952
953 ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
954 ubi->fm_disabled = (!fm_autoconvert || disable_fm) ? 1 : 0;
955 if (fm_debug)
956 ubi_enable_dbg_chk_fastmap(ubi);
957
958 if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
959 <= UBI_FM_MAX_START) {
960 ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
961 UBI_FM_MAX_START);
962 ubi->fm_disabled = 1;
963 }
964
965 ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
966 ubi_msg(ubi, "default fastmap WL pool size: %d",
967 ubi->fm_wl_pool.max_size);
968 #else
969 ubi->fm_disabled = 1;
970 #endif
971 mutex_init(&ubi->buf_mutex);
972 mutex_init(&ubi->ckvol_mutex);
973 mutex_init(&ubi->device_mutex);
974 spin_lock_init(&ubi->volumes_lock);
975 init_rwsem(&ubi->fm_protect);
976 init_rwsem(&ubi->fm_eba_sem);
977
978 ubi_msg(ubi, "attaching mtd%d", mtd->index);
979
980 err = io_init(ubi, max_beb_per1024);
981 if (err)
982 goto out_free;
983
984 err = -ENOMEM;
985 ubi->peb_buf = vmalloc(ubi->peb_size);
986 if (!ubi->peb_buf)
987 goto out_free;
988
989 #ifdef CONFIG_MTD_UBI_FASTMAP
990 ubi->fm_size = ubi_calc_fm_size(ubi);
991 ubi->fm_buf = vzalloc(ubi->fm_size);
992 if (!ubi->fm_buf)
993 goto out_free;
994 #endif
995 err = ubi_attach(ubi, disable_fm ? 1 : 0);
996 if (err) {
997 ubi_err(ubi, "failed to attach mtd%d, error %d",
998 mtd->index, err);
999 goto out_free;
1000 }
1001
1002 if (ubi->autoresize_vol_id != -1) {
1003 err = autoresize(ubi, ubi->autoresize_vol_id);
1004 if (err)
1005 goto out_detach;
1006 }
1007
1008 err = uif_init(ubi);
1009 if (err)
1010 goto out_detach;
1011
1012 err = ubi_debugfs_init_dev(ubi);
1013 if (err)
1014 goto out_uif;
1015
1016 ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
1017 if (IS_ERR(ubi->bgt_thread)) {
1018 err = PTR_ERR(ubi->bgt_thread);
1019 ubi_err(ubi, "cannot spawn \"%s\", error %d",
1020 ubi->bgt_name, err);
1021 goto out_debugfs;
1022 }
1023
1024 ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
1025 mtd->index, mtd->name, ubi->flash_size >> 20);
1026 ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
1027 ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
1028 ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
1029 ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
1030 ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
1031 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
1032 ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
1033 ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
1034 ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
1035 ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
1036 ubi->vtbl_slots);
1037 ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
1038 ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
1039 ubi->image_seq);
1040 ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
1041 ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
1042
1043 /*
1044 * The below lock makes sure we do not race with 'ubi_thread()' which
1045 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1046 */
1047 spin_lock(&ubi->wl_lock);
1048 ubi->thread_enabled = 1;
1049 wake_up_process(ubi->bgt_thread);
1050 spin_unlock(&ubi->wl_lock);
1051
1052 ubi_devices[ubi_num] = ubi;
1053 ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1054 return ubi_num;
1055
1056 out_debugfs:
1057 ubi_debugfs_exit_dev(ubi);
1058 out_uif:
1059 uif_close(ubi);
1060 out_detach:
1061 ubi_wl_close(ubi);
1062 ubi_free_all_volumes(ubi);
1063 vfree(ubi->vtbl);
1064 out_free:
1065 vfree(ubi->peb_buf);
1066 vfree(ubi->fm_buf);
1067 put_device(&ubi->dev);
1068 return err;
1069 }
1070
1071 /**
1072 * ubi_detach_mtd_dev - detach an MTD device.
1073 * @ubi_num: UBI device number to detach from
1074 * @anyway: detach MTD even if device reference count is not zero
1075 *
1076 * This function destroys an UBI device number @ubi_num and detaches the
1077 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1078 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1079 * exist.
1080 *
1081 * Note, the invocations of this function has to be serialized by the
1082 * @ubi_devices_mutex.
1083 */
ubi_detach_mtd_dev(int ubi_num,int anyway)1084 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1085 {
1086 struct ubi_device *ubi;
1087
1088 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1089 return -EINVAL;
1090
1091 ubi = ubi_get_device(ubi_num);
1092 if (!ubi)
1093 return -EINVAL;
1094
1095 spin_lock(&ubi_devices_lock);
1096 put_device(&ubi->dev);
1097 ubi->ref_count -= 1;
1098 if (ubi->ref_count) {
1099 if (!anyway) {
1100 spin_unlock(&ubi_devices_lock);
1101 return -EBUSY;
1102 }
1103 /* This may only happen if there is a bug */
1104 ubi_err(ubi, "%s reference count %d, destroy anyway",
1105 ubi->ubi_name, ubi->ref_count);
1106 }
1107 ubi_devices[ubi_num] = NULL;
1108 spin_unlock(&ubi_devices_lock);
1109
1110 ubi_assert(ubi_num == ubi->ubi_num);
1111 ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1112 ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
1113 #ifdef CONFIG_MTD_UBI_FASTMAP
1114 /* If we don't write a new fastmap at detach time we lose all
1115 * EC updates that have been made since the last written fastmap.
1116 * In case of fastmap debugging we omit the update to simulate an
1117 * unclean shutdown. */
1118 if (!ubi_dbg_chk_fastmap(ubi))
1119 ubi_update_fastmap(ubi);
1120 #endif
1121 /*
1122 * Before freeing anything, we have to stop the background thread to
1123 * prevent it from doing anything on this device while we are freeing.
1124 */
1125 if (ubi->bgt_thread)
1126 kthread_stop(ubi->bgt_thread);
1127
1128 #ifdef CONFIG_MTD_UBI_FASTMAP
1129 cancel_work_sync(&ubi->fm_work);
1130 #endif
1131 ubi_debugfs_exit_dev(ubi);
1132 uif_close(ubi);
1133
1134 ubi_wl_close(ubi);
1135 ubi_free_internal_volumes(ubi);
1136 vfree(ubi->vtbl);
1137 vfree(ubi->peb_buf);
1138 vfree(ubi->fm_buf);
1139 ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1140 put_mtd_device(ubi->mtd);
1141 put_device(&ubi->dev);
1142 return 0;
1143 }
1144
1145 /**
1146 * open_mtd_by_chdev - open an MTD device by its character device node path.
1147 * @mtd_dev: MTD character device node path
1148 *
1149 * This helper function opens an MTD device by its character node device path.
1150 * Returns MTD device description object in case of success and a negative
1151 * error code in case of failure.
1152 */
open_mtd_by_chdev(const char * mtd_dev)1153 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1154 {
1155 int err, minor;
1156 struct path path;
1157 struct kstat stat;
1158
1159 /* Probably this is an MTD character device node path */
1160 err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1161 if (err)
1162 return ERR_PTR(err);
1163
1164 err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
1165 path_put(&path);
1166 if (err)
1167 return ERR_PTR(err);
1168
1169 /* MTD device number is defined by the major / minor numbers */
1170 if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))
1171 return ERR_PTR(-EINVAL);
1172
1173 minor = MINOR(stat.rdev);
1174
1175 if (minor & 1)
1176 /*
1177 * Just do not think the "/dev/mtdrX" devices support is need,
1178 * so do not support them to avoid doing extra work.
1179 */
1180 return ERR_PTR(-EINVAL);
1181
1182 return get_mtd_device(NULL, minor / 2);
1183 }
1184
1185 /**
1186 * open_mtd_device - open MTD device by name, character device path, or number.
1187 * @mtd_dev: name, character device node path, or MTD device device number
1188 *
1189 * This function tries to open and MTD device described by @mtd_dev string,
1190 * which is first treated as ASCII MTD device number, and if it is not true, it
1191 * is treated as MTD device name, and if that is also not true, it is treated
1192 * as MTD character device node path. Returns MTD device description object in
1193 * case of success and a negative error code in case of failure.
1194 */
open_mtd_device(const char * mtd_dev)1195 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1196 {
1197 struct mtd_info *mtd;
1198 int mtd_num;
1199 char *endp;
1200
1201 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1202 if (*endp != '\0' || mtd_dev == endp) {
1203 /*
1204 * This does not look like an ASCII integer, probably this is
1205 * MTD device name.
1206 */
1207 mtd = get_mtd_device_nm(mtd_dev);
1208 if (PTR_ERR(mtd) == -ENODEV)
1209 /* Probably this is an MTD character device node path */
1210 mtd = open_mtd_by_chdev(mtd_dev);
1211 } else
1212 mtd = get_mtd_device(NULL, mtd_num);
1213
1214 return mtd;
1215 }
1216
ubi_init(void)1217 static int __init ubi_init(void)
1218 {
1219 int err, i, k;
1220
1221 /* Ensure that EC and VID headers have correct size */
1222 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1223 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1224
1225 if (mtd_devs > UBI_MAX_DEVICES) {
1226 pr_err("UBI error: too many MTD devices, maximum is %d\n",
1227 UBI_MAX_DEVICES);
1228 return -EINVAL;
1229 }
1230
1231 /* Create base sysfs directory and sysfs files */
1232 err = class_register(&ubi_class);
1233 if (err < 0)
1234 return err;
1235
1236 err = misc_register(&ubi_ctrl_cdev);
1237 if (err) {
1238 pr_err("UBI error: cannot register device\n");
1239 goto out;
1240 }
1241
1242 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1243 sizeof(struct ubi_wl_entry),
1244 0, 0, NULL);
1245 if (!ubi_wl_entry_slab) {
1246 err = -ENOMEM;
1247 goto out_dev_unreg;
1248 }
1249
1250 err = ubi_debugfs_init();
1251 if (err)
1252 goto out_slab;
1253
1254
1255 /* Attach MTD devices */
1256 for (i = 0; i < mtd_devs; i++) {
1257 struct mtd_dev_param *p = &mtd_dev_param[i];
1258 struct mtd_info *mtd;
1259
1260 cond_resched();
1261
1262 mtd = open_mtd_device(p->name);
1263 if (IS_ERR(mtd)) {
1264 err = PTR_ERR(mtd);
1265 pr_err("UBI error: cannot open mtd %s, error %d\n",
1266 p->name, err);
1267 /* See comment below re-ubi_is_module(). */
1268 if (ubi_is_module())
1269 goto out_detach;
1270 continue;
1271 }
1272
1273 mutex_lock(&ubi_devices_mutex);
1274 err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1275 p->vid_hdr_offs, p->max_beb_per1024,
1276 p->enable_fm == 0);
1277 mutex_unlock(&ubi_devices_mutex);
1278 if (err < 0) {
1279 pr_err("UBI error: cannot attach mtd%d\n",
1280 mtd->index);
1281 put_mtd_device(mtd);
1282
1283 /*
1284 * Originally UBI stopped initializing on any error.
1285 * However, later on it was found out that this
1286 * behavior is not very good when UBI is compiled into
1287 * the kernel and the MTD devices to attach are passed
1288 * through the command line. Indeed, UBI failure
1289 * stopped whole boot sequence.
1290 *
1291 * To fix this, we changed the behavior for the
1292 * non-module case, but preserved the old behavior for
1293 * the module case, just for compatibility. This is a
1294 * little inconsistent, though.
1295 */
1296 if (ubi_is_module())
1297 goto out_detach;
1298 }
1299 }
1300
1301 err = ubiblock_init();
1302 if (err) {
1303 pr_err("UBI error: block: cannot initialize, error %d\n", err);
1304
1305 /* See comment above re-ubi_is_module(). */
1306 if (ubi_is_module())
1307 goto out_detach;
1308 }
1309
1310 return 0;
1311
1312 out_detach:
1313 for (k = 0; k < i; k++)
1314 if (ubi_devices[k]) {
1315 mutex_lock(&ubi_devices_mutex);
1316 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1317 mutex_unlock(&ubi_devices_mutex);
1318 }
1319 ubi_debugfs_exit();
1320 out_slab:
1321 kmem_cache_destroy(ubi_wl_entry_slab);
1322 out_dev_unreg:
1323 misc_deregister(&ubi_ctrl_cdev);
1324 out:
1325 class_unregister(&ubi_class);
1326 pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1327 return err;
1328 }
1329 late_initcall(ubi_init);
1330
ubi_exit(void)1331 static void __exit ubi_exit(void)
1332 {
1333 int i;
1334
1335 ubiblock_exit();
1336
1337 for (i = 0; i < UBI_MAX_DEVICES; i++)
1338 if (ubi_devices[i]) {
1339 mutex_lock(&ubi_devices_mutex);
1340 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1341 mutex_unlock(&ubi_devices_mutex);
1342 }
1343 ubi_debugfs_exit();
1344 kmem_cache_destroy(ubi_wl_entry_slab);
1345 misc_deregister(&ubi_ctrl_cdev);
1346 class_unregister(&ubi_class);
1347 }
1348 module_exit(ubi_exit);
1349
1350 /**
1351 * bytes_str_to_int - convert a number of bytes string into an integer.
1352 * @str: the string to convert
1353 *
1354 * This function returns positive resulting integer in case of success and a
1355 * negative error code in case of failure.
1356 */
bytes_str_to_int(const char * str)1357 static int bytes_str_to_int(const char *str)
1358 {
1359 char *endp;
1360 unsigned long result;
1361
1362 result = simple_strtoul(str, &endp, 0);
1363 if (str == endp || result >= INT_MAX) {
1364 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1365 return -EINVAL;
1366 }
1367
1368 switch (*endp) {
1369 case 'G':
1370 result *= 1024;
1371 fallthrough;
1372 case 'M':
1373 result *= 1024;
1374 fallthrough;
1375 case 'K':
1376 result *= 1024;
1377 break;
1378 case '\0':
1379 break;
1380 default:
1381 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1382 return -EINVAL;
1383 }
1384
1385 return result;
1386 }
1387
1388 /**
1389 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1390 * @val: the parameter value to parse
1391 * @kp: not used
1392 *
1393 * This function returns zero in case of success and a negative error code in
1394 * case of error.
1395 */
ubi_mtd_param_parse(const char * val,const struct kernel_param * kp)1396 static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp)
1397 {
1398 int i, len;
1399 struct mtd_dev_param *p;
1400 char buf[MTD_PARAM_LEN_MAX];
1401 char *pbuf = &buf[0];
1402 char *tokens[MTD_PARAM_MAX_COUNT], *token;
1403
1404 if (!val)
1405 return -EINVAL;
1406
1407 if (mtd_devs == UBI_MAX_DEVICES) {
1408 pr_err("UBI error: too many parameters, max. is %d\n",
1409 UBI_MAX_DEVICES);
1410 return -EINVAL;
1411 }
1412
1413 len = strnlen(val, MTD_PARAM_LEN_MAX);
1414 if (len == MTD_PARAM_LEN_MAX) {
1415 pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1416 val, MTD_PARAM_LEN_MAX);
1417 return -EINVAL;
1418 }
1419
1420 if (len == 0) {
1421 pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1422 return 0;
1423 }
1424
1425 strcpy(buf, val);
1426
1427 /* Get rid of the final newline */
1428 if (buf[len - 1] == '\n')
1429 buf[len - 1] = '\0';
1430
1431 for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1432 tokens[i] = strsep(&pbuf, ",");
1433
1434 if (pbuf) {
1435 pr_err("UBI error: too many arguments at \"%s\"\n", val);
1436 return -EINVAL;
1437 }
1438
1439 p = &mtd_dev_param[mtd_devs];
1440 strcpy(&p->name[0], tokens[0]);
1441
1442 token = tokens[1];
1443 if (token) {
1444 p->vid_hdr_offs = bytes_str_to_int(token);
1445
1446 if (p->vid_hdr_offs < 0)
1447 return p->vid_hdr_offs;
1448 }
1449
1450 token = tokens[2];
1451 if (token) {
1452 int err = kstrtoint(token, 10, &p->max_beb_per1024);
1453
1454 if (err) {
1455 pr_err("UBI error: bad value for max_beb_per1024 parameter: %s\n",
1456 token);
1457 return -EINVAL;
1458 }
1459 }
1460
1461 token = tokens[3];
1462 if (token) {
1463 int err = kstrtoint(token, 10, &p->ubi_num);
1464
1465 if (err) {
1466 pr_err("UBI error: bad value for ubi_num parameter: %s\n",
1467 token);
1468 return -EINVAL;
1469 }
1470 } else
1471 p->ubi_num = UBI_DEV_NUM_AUTO;
1472
1473 token = tokens[4];
1474 if (token) {
1475 int err = kstrtoint(token, 10, &p->enable_fm);
1476
1477 if (err) {
1478 pr_err("UBI error: bad value for enable_fm parameter: %s\n",
1479 token);
1480 return -EINVAL;
1481 }
1482 } else
1483 p->enable_fm = 0;
1484
1485 mtd_devs += 1;
1486 return 0;
1487 }
1488
1489 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 0400);
1490 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1491 "Multiple \"mtd\" parameters may be specified.\n"
1492 "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1493 "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1494 "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1495 __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1496 "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1497 "Optional \"enable_fm\" parameter determines whether to enable fastmap during attach. If the value is non-zero, fastmap is enabled. Default value is 0.\n"
1498 "\n"
1499 "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1500 "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"
1501 "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"
1502 "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"
1503 "example 5: mtd=1,0,0,5 mtd=2,0,0,6,1 - attach MTD device /dev/mtd1 to UBI 5 and disable fastmap; attach MTD device /dev/mtd2 to UBI 6 and enable fastmap.(only works when fastmap is enabled and fm_autoconvert=Y).\n"
1504 "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1505 #ifdef CONFIG_MTD_UBI_FASTMAP
1506 module_param(fm_autoconvert, bool, 0644);
1507 MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1508 module_param(fm_debug, bool, 0);
1509 MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1510 #endif
1511 MODULE_VERSION(__stringify(UBI_VERSION));
1512 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1513 MODULE_AUTHOR("Artem Bityutskiy");
1514 MODULE_LICENSE("GPL");
1515 MODULE_IMPORT_NS(VFS_internal_I_am_really_a_filesystem_and_am_NOT_a_driver);
1516