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/of.h>
31 #include <linux/slab.h>
32 #include <linux/major.h>
33 #include "ubi.h"
34
35 /* Maximum length of the 'mtd=' parameter */
36 #define MTD_PARAM_LEN_MAX 64
37
38 /* Maximum number of comma-separated items in the 'mtd=' parameter */
39 #define MTD_PARAM_MAX_COUNT 6
40
41 /* Maximum value for the number of bad PEBs per 1024 PEBs */
42 #define MAX_MTD_UBI_BEB_LIMIT 768
43
44 #ifdef CONFIG_MTD_UBI_MODULE
45 #define ubi_is_module() 1
46 #else
47 #define ubi_is_module() 0
48 #endif
49
50 /**
51 * struct mtd_dev_param - MTD device parameter description data structure.
52 * @name: MTD character device node path, MTD device name, or MTD device number
53 * string
54 * @ubi_num: UBI number
55 * @vid_hdr_offs: VID header offset
56 * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
57 * @enable_fm: enable fastmap when value is non-zero
58 * @need_resv_pool: reserve pool->max_size pebs when value is none-zero
59 */
60 struct mtd_dev_param {
61 char name[MTD_PARAM_LEN_MAX];
62 int ubi_num;
63 int vid_hdr_offs;
64 int max_beb_per1024;
65 int enable_fm;
66 int need_resv_pool;
67 };
68
69 /* Numbers of elements set in the @mtd_dev_param array */
70 static int mtd_devs;
71
72 /* MTD devices specification parameters */
73 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
74 #ifdef CONFIG_MTD_UBI_FASTMAP
75 /* UBI module parameter to enable fastmap automatically on non-fastmap images */
76 static bool fm_autoconvert;
77 static bool fm_debug;
78 #endif
79
80 /* Slab cache for wear-leveling entries */
81 struct kmem_cache *ubi_wl_entry_slab;
82
83 /* UBI control character device */
84 static struct miscdevice ubi_ctrl_cdev = {
85 .minor = MISC_DYNAMIC_MINOR,
86 .name = "ubi_ctrl",
87 .fops = &ubi_ctrl_cdev_operations,
88 };
89
90 /* All UBI devices in system */
91 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
92
93 /* Serializes UBI devices creations and removals */
94 DEFINE_MUTEX(ubi_devices_mutex);
95
96 /* Protects @ubi_devices, @ubi->ref_count and @ubi->is_dead */
97 static DEFINE_SPINLOCK(ubi_devices_lock);
98
99 /* "Show" method for files in '/<sysfs>/class/ubi/' */
100 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
version_show(const struct class * class,const struct class_attribute * attr,char * buf)101 static ssize_t version_show(const struct class *class, const struct class_attribute *attr,
102 char *buf)
103 {
104 return sprintf(buf, "%d\n", UBI_VERSION);
105 }
106 static CLASS_ATTR_RO(version);
107
108 static struct attribute *ubi_class_attrs[] = {
109 &class_attr_version.attr,
110 NULL,
111 };
112 ATTRIBUTE_GROUPS(ubi_class);
113
114 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
115 const struct class ubi_class = {
116 .name = UBI_NAME_STR,
117 .class_groups = ubi_class_groups,
118 };
119
120 static ssize_t dev_attribute_show(struct device *dev,
121 struct device_attribute *attr, char *buf);
122
123 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
124 static struct device_attribute dev_eraseblock_size =
125 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
126 static struct device_attribute dev_avail_eraseblocks =
127 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
128 static struct device_attribute dev_total_eraseblocks =
129 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
130 static struct device_attribute dev_volumes_count =
131 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
132 static struct device_attribute dev_max_ec =
133 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
134 static struct device_attribute dev_reserved_for_bad =
135 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
136 static struct device_attribute dev_bad_peb_count =
137 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
138 static struct device_attribute dev_max_vol_count =
139 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
140 static struct device_attribute dev_min_io_size =
141 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
142 static struct device_attribute dev_bgt_enabled =
143 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
144 static struct device_attribute dev_mtd_num =
145 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
146 static struct device_attribute dev_ro_mode =
147 __ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
148
149 /**
150 * ubi_volume_notify - send a volume change notification.
151 * @ubi: UBI device description object
152 * @vol: volume description object of the changed volume
153 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
154 *
155 * This is a helper function which notifies all subscribers about a volume
156 * change event (creation, removal, re-sizing, re-naming, updating). Returns
157 * zero in case of success and a negative error code in case of failure.
158 */
ubi_volume_notify(struct ubi_device * ubi,struct ubi_volume * vol,int ntype)159 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
160 {
161 int ret;
162 struct ubi_notification nt;
163
164 ubi_do_get_device_info(ubi, &nt.di);
165 ubi_do_get_volume_info(ubi, vol, &nt.vi);
166
167 switch (ntype) {
168 case UBI_VOLUME_ADDED:
169 case UBI_VOLUME_REMOVED:
170 case UBI_VOLUME_RESIZED:
171 case UBI_VOLUME_RENAMED:
172 ret = ubi_update_fastmap(ubi);
173 if (ret)
174 ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
175 }
176
177 return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
178 }
179
180 /**
181 * ubi_notify_all - send a notification to all volumes.
182 * @ubi: UBI device description object
183 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
184 * @nb: the notifier to call
185 *
186 * This function walks all volumes of UBI device @ubi and sends the @ntype
187 * notification for each volume. If @nb is %NULL, then all registered notifiers
188 * are called, otherwise only the @nb notifier is called. Returns the number of
189 * sent notifications.
190 */
ubi_notify_all(struct ubi_device * ubi,int ntype,struct notifier_block * nb)191 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
192 {
193 struct ubi_notification nt;
194 int i, count = 0;
195
196 ubi_do_get_device_info(ubi, &nt.di);
197
198 mutex_lock(&ubi->device_mutex);
199 for (i = 0; i < ubi->vtbl_slots; i++) {
200 /*
201 * Since the @ubi->device is locked, and we are not going to
202 * change @ubi->volumes, we do not have to lock
203 * @ubi->volumes_lock.
204 */
205 if (!ubi->volumes[i])
206 continue;
207
208 ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
209 if (nb)
210 nb->notifier_call(nb, ntype, &nt);
211 else
212 blocking_notifier_call_chain(&ubi_notifiers, ntype,
213 &nt);
214 count += 1;
215 }
216 mutex_unlock(&ubi->device_mutex);
217
218 return count;
219 }
220
221 /**
222 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
223 * @nb: the notifier to call
224 *
225 * This function walks all UBI devices and volumes and sends the
226 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
227 * registered notifiers are called, otherwise only the @nb notifier is called.
228 * Returns the number of sent notifications.
229 */
ubi_enumerate_volumes(struct notifier_block * nb)230 int ubi_enumerate_volumes(struct notifier_block *nb)
231 {
232 int i, count = 0;
233
234 /*
235 * Since the @ubi_devices_mutex is locked, and we are not going to
236 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
237 */
238 for (i = 0; i < UBI_MAX_DEVICES; i++) {
239 struct ubi_device *ubi = ubi_devices[i];
240
241 if (!ubi)
242 continue;
243 count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
244 }
245
246 return count;
247 }
248
249 /**
250 * ubi_get_device - get UBI device.
251 * @ubi_num: UBI device number
252 *
253 * This function returns UBI device description object for UBI device number
254 * @ubi_num, or %NULL if the device does not exist. This function increases the
255 * device reference count to prevent removal of the device. In other words, the
256 * device cannot be removed if its reference count is not zero.
257 */
ubi_get_device(int ubi_num)258 struct ubi_device *ubi_get_device(int ubi_num)
259 {
260 struct ubi_device *ubi;
261
262 spin_lock(&ubi_devices_lock);
263 ubi = ubi_devices[ubi_num];
264 if (ubi && ubi->is_dead)
265 ubi = NULL;
266
267 if (ubi) {
268 ubi_assert(ubi->ref_count >= 0);
269 ubi->ref_count += 1;
270 get_device(&ubi->dev);
271 }
272 spin_unlock(&ubi_devices_lock);
273
274 return ubi;
275 }
276
277 /**
278 * ubi_put_device - drop an UBI device reference.
279 * @ubi: UBI device description object
280 */
ubi_put_device(struct ubi_device * ubi)281 void ubi_put_device(struct ubi_device *ubi)
282 {
283 spin_lock(&ubi_devices_lock);
284 ubi->ref_count -= 1;
285 put_device(&ubi->dev);
286 spin_unlock(&ubi_devices_lock);
287 }
288
289 /**
290 * ubi_get_by_major - get UBI device by character device major number.
291 * @major: major number
292 *
293 * This function is similar to 'ubi_get_device()', but it searches the device
294 * by its major number.
295 */
ubi_get_by_major(int major)296 struct ubi_device *ubi_get_by_major(int major)
297 {
298 int i;
299 struct ubi_device *ubi;
300
301 spin_lock(&ubi_devices_lock);
302 for (i = 0; i < UBI_MAX_DEVICES; i++) {
303 ubi = ubi_devices[i];
304 if (ubi && !ubi->is_dead && MAJOR(ubi->cdev.dev) == major) {
305 ubi_assert(ubi->ref_count >= 0);
306 ubi->ref_count += 1;
307 get_device(&ubi->dev);
308 spin_unlock(&ubi_devices_lock);
309 return ubi;
310 }
311 }
312 spin_unlock(&ubi_devices_lock);
313
314 return NULL;
315 }
316
317 /**
318 * ubi_major2num - get UBI device number by character device major number.
319 * @major: major number
320 *
321 * This function searches UBI device number object by its major number. If UBI
322 * device was not found, this function returns -ENODEV, otherwise the UBI device
323 * number is returned.
324 */
ubi_major2num(int major)325 int ubi_major2num(int major)
326 {
327 int i, ubi_num = -ENODEV;
328
329 spin_lock(&ubi_devices_lock);
330 for (i = 0; i < UBI_MAX_DEVICES; i++) {
331 struct ubi_device *ubi = ubi_devices[i];
332
333 if (ubi && !ubi->is_dead && MAJOR(ubi->cdev.dev) == major) {
334 ubi_num = ubi->ubi_num;
335 break;
336 }
337 }
338 spin_unlock(&ubi_devices_lock);
339
340 return ubi_num;
341 }
342
343 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
dev_attribute_show(struct device * dev,struct device_attribute * attr,char * buf)344 static ssize_t dev_attribute_show(struct device *dev,
345 struct device_attribute *attr, char *buf)
346 {
347 ssize_t ret;
348 struct ubi_device *ubi;
349
350 /*
351 * The below code looks weird, but it actually makes sense. We get the
352 * UBI device reference from the contained 'struct ubi_device'. But it
353 * is unclear if the device was removed or not yet. Indeed, if the
354 * device was removed before we increased its reference count,
355 * 'ubi_get_device()' will return -ENODEV and we fail.
356 *
357 * Remember, 'struct ubi_device' is freed in the release function, so
358 * we still can use 'ubi->ubi_num'.
359 */
360 ubi = container_of(dev, struct ubi_device, dev);
361
362 if (attr == &dev_eraseblock_size)
363 ret = sprintf(buf, "%d\n", ubi->leb_size);
364 else if (attr == &dev_avail_eraseblocks)
365 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
366 else if (attr == &dev_total_eraseblocks)
367 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
368 else if (attr == &dev_volumes_count)
369 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
370 else if (attr == &dev_max_ec)
371 ret = sprintf(buf, "%d\n", ubi->max_ec);
372 else if (attr == &dev_reserved_for_bad)
373 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
374 else if (attr == &dev_bad_peb_count)
375 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
376 else if (attr == &dev_max_vol_count)
377 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
378 else if (attr == &dev_min_io_size)
379 ret = sprintf(buf, "%d\n", ubi->min_io_size);
380 else if (attr == &dev_bgt_enabled)
381 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
382 else if (attr == &dev_mtd_num)
383 ret = sprintf(buf, "%d\n", ubi->mtd->index);
384 else if (attr == &dev_ro_mode)
385 ret = sprintf(buf, "%d\n", ubi->ro_mode);
386 else
387 ret = -EINVAL;
388
389 return ret;
390 }
391
392 static struct attribute *ubi_dev_attrs[] = {
393 &dev_eraseblock_size.attr,
394 &dev_avail_eraseblocks.attr,
395 &dev_total_eraseblocks.attr,
396 &dev_volumes_count.attr,
397 &dev_max_ec.attr,
398 &dev_reserved_for_bad.attr,
399 &dev_bad_peb_count.attr,
400 &dev_max_vol_count.attr,
401 &dev_min_io_size.attr,
402 &dev_bgt_enabled.attr,
403 &dev_mtd_num.attr,
404 &dev_ro_mode.attr,
405 NULL
406 };
407 ATTRIBUTE_GROUPS(ubi_dev);
408
dev_release(struct device * dev)409 static void dev_release(struct device *dev)
410 {
411 struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
412
413 kfree(ubi);
414 }
415
416 /**
417 * kill_volumes - destroy all user volumes.
418 * @ubi: UBI device description object
419 */
kill_volumes(struct ubi_device * ubi)420 static void kill_volumes(struct ubi_device *ubi)
421 {
422 int i;
423
424 for (i = 0; i < ubi->vtbl_slots; i++)
425 if (ubi->volumes[i])
426 ubi_free_volume(ubi, ubi->volumes[i]);
427 }
428
429 /**
430 * uif_init - initialize user interfaces for an UBI device.
431 * @ubi: UBI device description object
432 *
433 * This function initializes various user interfaces for an UBI device. If the
434 * initialization fails at an early stage, this function frees all the
435 * resources it allocated, returns an error.
436 *
437 * This function returns zero in case of success and a negative error code in
438 * case of failure.
439 */
uif_init(struct ubi_device * ubi)440 static int uif_init(struct ubi_device *ubi)
441 {
442 int i, err;
443 dev_t dev;
444
445 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
446
447 /*
448 * Major numbers for the UBI character devices are allocated
449 * dynamically. Major numbers of volume character devices are
450 * equivalent to ones of the corresponding UBI character device. Minor
451 * numbers of UBI character devices are 0, while minor numbers of
452 * volume character devices start from 1. Thus, we allocate one major
453 * number and ubi->vtbl_slots + 1 minor numbers.
454 */
455 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
456 if (err) {
457 ubi_err(ubi, "cannot register UBI character devices");
458 return err;
459 }
460
461 ubi->dev.devt = dev;
462
463 ubi_assert(MINOR(dev) == 0);
464 cdev_init(&ubi->cdev, &ubi_cdev_operations);
465 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
466 ubi->cdev.owner = THIS_MODULE;
467
468 dev_set_name(&ubi->dev, UBI_NAME_STR "%d", ubi->ubi_num);
469 err = cdev_device_add(&ubi->cdev, &ubi->dev);
470 if (err)
471 goto out_unreg;
472
473 for (i = 0; i < ubi->vtbl_slots; i++)
474 if (ubi->volumes[i]) {
475 err = ubi_add_volume(ubi, ubi->volumes[i]);
476 if (err) {
477 ubi_err(ubi, "cannot add volume %d", i);
478 ubi->volumes[i] = NULL;
479 goto out_volumes;
480 }
481 }
482
483 return 0;
484
485 out_volumes:
486 kill_volumes(ubi);
487 cdev_device_del(&ubi->cdev, &ubi->dev);
488 out_unreg:
489 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
490 ubi_err(ubi, "cannot initialize UBI %s, error %d",
491 ubi->ubi_name, err);
492 return err;
493 }
494
495 /**
496 * uif_close - close user interfaces for an UBI device.
497 * @ubi: UBI device description object
498 *
499 * Note, since this function un-registers UBI volume device objects (@vol->dev),
500 * the memory allocated voe the volumes is freed as well (in the release
501 * function).
502 */
uif_close(struct ubi_device * ubi)503 static void uif_close(struct ubi_device *ubi)
504 {
505 kill_volumes(ubi);
506 cdev_device_del(&ubi->cdev, &ubi->dev);
507 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
508 }
509
510 /**
511 * ubi_free_volumes_from - free volumes from specific index.
512 * @ubi: UBI device description object
513 * @from: the start index used for volume free.
514 */
ubi_free_volumes_from(struct ubi_device * ubi,int from)515 static void ubi_free_volumes_from(struct ubi_device *ubi, int from)
516 {
517 int i;
518
519 for (i = from; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
520 if (!ubi->volumes[i] || ubi->volumes[i]->is_dead)
521 continue;
522 ubi_eba_replace_table(ubi->volumes[i], NULL);
523 ubi_fastmap_destroy_checkmap(ubi->volumes[i]);
524 kfree(ubi->volumes[i]);
525 ubi->volumes[i] = NULL;
526 }
527 }
528
529 /**
530 * ubi_free_all_volumes - free all volumes.
531 * @ubi: UBI device description object
532 */
ubi_free_all_volumes(struct ubi_device * ubi)533 void ubi_free_all_volumes(struct ubi_device *ubi)
534 {
535 ubi_free_volumes_from(ubi, 0);
536 }
537
538 /**
539 * ubi_free_internal_volumes - free internal volumes.
540 * @ubi: UBI device description object
541 */
ubi_free_internal_volumes(struct ubi_device * ubi)542 void ubi_free_internal_volumes(struct ubi_device *ubi)
543 {
544 ubi_free_volumes_from(ubi, ubi->vtbl_slots);
545 }
546
get_bad_peb_limit(const struct ubi_device * ubi,int max_beb_per1024)547 static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
548 {
549 int limit, device_pebs;
550 uint64_t device_size;
551
552 if (!max_beb_per1024) {
553 /*
554 * Since max_beb_per1024 has not been set by the user in either
555 * the cmdline or Kconfig, use mtd_max_bad_blocks to set the
556 * limit if it is supported by the device.
557 */
558 limit = mtd_max_bad_blocks(ubi->mtd, 0, ubi->mtd->size);
559 if (limit < 0)
560 return 0;
561 return limit;
562 }
563
564 /*
565 * Here we are using size of the entire flash chip and
566 * not just the MTD partition size because the maximum
567 * number of bad eraseblocks is a percentage of the
568 * whole device and bad eraseblocks are not fairly
569 * distributed over the flash chip. So the worst case
570 * is that all the bad eraseblocks of the chip are in
571 * the MTD partition we are attaching (ubi->mtd).
572 */
573 device_size = mtd_get_device_size(ubi->mtd);
574 device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
575 limit = mult_frac(device_pebs, max_beb_per1024, 1024);
576
577 /* Round it up */
578 if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
579 limit += 1;
580
581 return limit;
582 }
583
584 /**
585 * io_init - initialize I/O sub-system for a given UBI device.
586 * @ubi: UBI device description object
587 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
588 *
589 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
590 * assumed:
591 * o EC header is always at offset zero - this cannot be changed;
592 * o VID header starts just after the EC header at the closest address
593 * aligned to @io->hdrs_min_io_size;
594 * o data starts just after the VID header at the closest address aligned to
595 * @io->min_io_size
596 *
597 * This function returns zero in case of success and a negative error code in
598 * case of failure.
599 */
io_init(struct ubi_device * ubi,int max_beb_per1024)600 static int io_init(struct ubi_device *ubi, int max_beb_per1024)
601 {
602 dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
603 dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
604
605 if (ubi->mtd->numeraseregions != 0) {
606 /*
607 * Some flashes have several erase regions. Different regions
608 * may have different eraseblock size and other
609 * characteristics. It looks like mostly multi-region flashes
610 * have one "main" region and one or more small regions to
611 * store boot loader code or boot parameters or whatever. I
612 * guess we should just pick the largest region. But this is
613 * not implemented.
614 */
615 ubi_err(ubi, "multiple regions, not implemented");
616 return -EINVAL;
617 }
618
619 if (ubi->vid_hdr_offset < 0)
620 return -EINVAL;
621
622 /*
623 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
624 * physical eraseblocks maximum.
625 */
626
627 ubi->peb_size = ubi->mtd->erasesize;
628 ubi->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
629 ubi->flash_size = ubi->mtd->size;
630
631 if (mtd_can_have_bb(ubi->mtd)) {
632 ubi->bad_allowed = 1;
633 ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
634 }
635
636 if (ubi->mtd->type == MTD_NORFLASH)
637 ubi->nor_flash = 1;
638
639 ubi->min_io_size = ubi->mtd->writesize;
640 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
641
642 /*
643 * Make sure minimal I/O unit is power of 2. Note, there is no
644 * fundamental reason for this assumption. It is just an optimization
645 * which allows us to avoid costly division operations.
646 */
647 if (!is_power_of_2(ubi->min_io_size)) {
648 ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
649 ubi->min_io_size);
650 return -EINVAL;
651 }
652
653 ubi_assert(ubi->hdrs_min_io_size > 0);
654 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
655 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
656
657 ubi->max_write_size = ubi->mtd->writebufsize;
658 /*
659 * Maximum write size has to be greater or equivalent to min. I/O
660 * size, and be multiple of min. I/O size.
661 */
662 if (ubi->max_write_size < ubi->min_io_size ||
663 ubi->max_write_size % ubi->min_io_size ||
664 !is_power_of_2(ubi->max_write_size)) {
665 ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
666 ubi->max_write_size, ubi->min_io_size);
667 return -EINVAL;
668 }
669
670 /* Calculate default aligned sizes of EC and VID headers */
671 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
672 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
673
674 dbg_gen("min_io_size %d", ubi->min_io_size);
675 dbg_gen("max_write_size %d", ubi->max_write_size);
676 dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
677 dbg_gen("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
678 dbg_gen("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
679
680 if (ubi->vid_hdr_offset == 0)
681 /* Default offset */
682 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
683 ubi->ec_hdr_alsize;
684 else {
685 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
686 ~(ubi->hdrs_min_io_size - 1);
687 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
688 ubi->vid_hdr_aloffset;
689 }
690
691 /*
692 * Memory allocation for VID header is ubi->vid_hdr_alsize
693 * which is described in comments in io.c.
694 * Make sure VID header shift + UBI_VID_HDR_SIZE not exceeds
695 * ubi->vid_hdr_alsize, so that all vid header operations
696 * won't access memory out of bounds.
697 */
698 if ((ubi->vid_hdr_shift + UBI_VID_HDR_SIZE) > ubi->vid_hdr_alsize) {
699 ubi_err(ubi, "Invalid VID header offset %d, VID header shift(%d)"
700 " + VID header size(%zu) > VID header aligned size(%d).",
701 ubi->vid_hdr_offset, ubi->vid_hdr_shift,
702 UBI_VID_HDR_SIZE, ubi->vid_hdr_alsize);
703 return -EINVAL;
704 }
705
706 /* Similar for the data offset */
707 ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
708 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
709
710 dbg_gen("vid_hdr_offset %d", ubi->vid_hdr_offset);
711 dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
712 dbg_gen("vid_hdr_shift %d", ubi->vid_hdr_shift);
713 dbg_gen("leb_start %d", ubi->leb_start);
714
715 /* The shift must be aligned to 32-bit boundary */
716 if (ubi->vid_hdr_shift % 4) {
717 ubi_err(ubi, "unaligned VID header shift %d",
718 ubi->vid_hdr_shift);
719 return -EINVAL;
720 }
721
722 /* Check sanity */
723 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
724 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
725 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
726 ubi->leb_start & (ubi->min_io_size - 1)) {
727 ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
728 ubi->vid_hdr_offset, ubi->leb_start);
729 return -EINVAL;
730 }
731
732 /*
733 * Set maximum amount of physical erroneous eraseblocks to be 10%.
734 * Erroneous PEB are those which have read errors.
735 */
736 ubi->max_erroneous = ubi->peb_count / 10;
737 if (ubi->max_erroneous < 16)
738 ubi->max_erroneous = 16;
739 dbg_gen("max_erroneous %d", ubi->max_erroneous);
740
741 /*
742 * It may happen that EC and VID headers are situated in one minimal
743 * I/O unit. In this case we can only accept this UBI image in
744 * read-only mode.
745 */
746 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
747 ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
748 ubi->ro_mode = 1;
749 }
750
751 ubi->leb_size = ubi->peb_size - ubi->leb_start;
752
753 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
754 ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
755 ubi->mtd->index);
756 ubi->ro_mode = 1;
757 }
758
759 /*
760 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
761 * unfortunately, MTD does not provide this information. We should loop
762 * over all physical eraseblocks and invoke mtd->block_is_bad() for
763 * each physical eraseblock. So, we leave @ubi->bad_peb_count
764 * uninitialized so far.
765 */
766
767 return 0;
768 }
769
770 /**
771 * autoresize - re-size the volume which has the "auto-resize" flag set.
772 * @ubi: UBI device description object
773 * @vol_id: ID of the volume to re-size
774 *
775 * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
776 * the volume table to the largest possible size. See comments in ubi-header.h
777 * for more description of the flag. Returns zero in case of success and a
778 * negative error code in case of failure.
779 */
autoresize(struct ubi_device * ubi,int vol_id)780 static int autoresize(struct ubi_device *ubi, int vol_id)
781 {
782 struct ubi_volume_desc desc;
783 struct ubi_volume *vol = ubi->volumes[vol_id];
784 int err, old_reserved_pebs = vol->reserved_pebs;
785
786 if (ubi->ro_mode) {
787 ubi_warn(ubi, "skip auto-resize because of R/O mode");
788 return 0;
789 }
790
791 /*
792 * Clear the auto-resize flag in the volume in-memory copy of the
793 * volume table, and 'ubi_resize_volume()' will propagate this change
794 * to the flash.
795 */
796 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
797
798 if (ubi->avail_pebs == 0) {
799 struct ubi_vtbl_record vtbl_rec;
800
801 /*
802 * No available PEBs to re-size the volume, clear the flag on
803 * flash and exit.
804 */
805 vtbl_rec = ubi->vtbl[vol_id];
806 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
807 if (err)
808 ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
809 vol_id);
810 } else {
811 desc.vol = vol;
812 err = ubi_resize_volume(&desc,
813 old_reserved_pebs + ubi->avail_pebs);
814 if (err)
815 ubi_err(ubi, "cannot auto-resize volume %d",
816 vol_id);
817 }
818
819 if (err)
820 return err;
821
822 ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
823 vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
824 return 0;
825 }
826
827 /**
828 * ubi_attach_mtd_dev - attach an MTD device.
829 * @mtd: MTD device description object
830 * @ubi_num: number to assign to the new UBI device
831 * @vid_hdr_offset: VID header offset
832 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
833 * @disable_fm: whether disable fastmap
834 * @need_resv_pool: whether reserve pebs to fill fm_pool
835 *
836 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
837 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
838 * which case this function finds a vacant device number and assigns it
839 * automatically. Returns the new UBI device number in case of success and a
840 * negative error code in case of failure.
841 *
842 * If @disable_fm is true, ubi doesn't create new fastmap even the module param
843 * 'fm_autoconvert' is set, and existed old fastmap will be destroyed after
844 * doing full scanning.
845 *
846 * Note, the invocations of this function has to be serialized by the
847 * @ubi_devices_mutex.
848 */
ubi_attach_mtd_dev(struct mtd_info * mtd,int ubi_num,int vid_hdr_offset,int max_beb_per1024,bool disable_fm,bool need_resv_pool)849 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
850 int vid_hdr_offset, int max_beb_per1024, bool disable_fm,
851 bool need_resv_pool)
852 {
853 struct ubi_device *ubi;
854 int i, err;
855
856 if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
857 return -EINVAL;
858
859 if (!max_beb_per1024)
860 max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
861
862 /*
863 * Check if we already have the same MTD device attached.
864 *
865 * Note, this function assumes that UBI devices creations and deletions
866 * are serialized, so it does not take the &ubi_devices_lock.
867 */
868 for (i = 0; i < UBI_MAX_DEVICES; i++) {
869 ubi = ubi_devices[i];
870 if (ubi && mtd->index == ubi->mtd->index) {
871 pr_err("ubi: mtd%d is already attached to ubi%d\n",
872 mtd->index, i);
873 return -EEXIST;
874 }
875 }
876
877 /*
878 * Make sure this MTD device is not emulated on top of an UBI volume
879 * already. Well, generally this recursion works fine, but there are
880 * different problems like the UBI module takes a reference to itself
881 * by attaching (and thus, opening) the emulated MTD device. This
882 * results in inability to unload the module. And in general it makes
883 * no sense to attach emulated MTD devices, so we prohibit this.
884 */
885 if (mtd->type == MTD_UBIVOLUME) {
886 pr_err("ubi: refuse attaching mtd%d - it is already emulated on top of UBI\n",
887 mtd->index);
888 return -EINVAL;
889 }
890
891 /*
892 * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes.
893 * MLC NAND is different and needs special care, otherwise UBI or UBIFS
894 * will die soon and you will lose all your data.
895 * Relax this rule if the partition we're attaching to operates in SLC
896 * mode.
897 */
898 if (mtd->type == MTD_MLCNANDFLASH &&
899 !(mtd->flags & MTD_SLC_ON_MLC_EMULATION)) {
900 pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n",
901 mtd->index);
902 return -EINVAL;
903 }
904
905 /* UBI cannot work on flashes with zero erasesize. */
906 if (!mtd->erasesize) {
907 pr_err("ubi: refuse attaching mtd%d - zero erasesize flash is not supported\n",
908 mtd->index);
909 return -EINVAL;
910 }
911
912 if (ubi_num == UBI_DEV_NUM_AUTO) {
913 /* Search for an empty slot in the @ubi_devices array */
914 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
915 if (!ubi_devices[ubi_num])
916 break;
917 if (ubi_num == UBI_MAX_DEVICES) {
918 pr_err("ubi: only %d UBI devices may be created\n",
919 UBI_MAX_DEVICES);
920 return -ENFILE;
921 }
922 } else {
923 if (ubi_num >= UBI_MAX_DEVICES)
924 return -EINVAL;
925
926 /* Make sure ubi_num is not busy */
927 if (ubi_devices[ubi_num]) {
928 pr_err("ubi: ubi%i already exists\n", ubi_num);
929 return -EEXIST;
930 }
931 }
932
933 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
934 if (!ubi)
935 return -ENOMEM;
936
937 device_initialize(&ubi->dev);
938 ubi->dev.release = dev_release;
939 ubi->dev.class = &ubi_class;
940 ubi->dev.groups = ubi_dev_groups;
941 ubi->dev.parent = &mtd->dev;
942
943 ubi->mtd = mtd;
944 ubi->ubi_num = ubi_num;
945 ubi->vid_hdr_offset = vid_hdr_offset;
946 ubi->autoresize_vol_id = -1;
947
948 #ifdef CONFIG_MTD_UBI_FASTMAP
949 ubi->fm_pool.used = ubi->fm_pool.size = 0;
950 ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
951
952 /*
953 * fm_pool.max_size is 5% of the total number of PEBs but it's also
954 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
955 */
956 ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
957 ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
958 ubi->fm_pool.max_size = max(ubi->fm_pool.max_size,
959 UBI_FM_MIN_POOL_SIZE);
960
961 ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
962 ubi->fm_pool_rsv_cnt = need_resv_pool ? ubi->fm_pool.max_size : 0;
963 ubi->fm_disabled = (!fm_autoconvert || disable_fm) ? 1 : 0;
964 if (fm_debug)
965 ubi_enable_dbg_chk_fastmap(ubi);
966
967 if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
968 <= UBI_FM_MAX_START) {
969 ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
970 UBI_FM_MAX_START);
971 ubi->fm_disabled = 1;
972 }
973
974 ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
975 ubi_msg(ubi, "default fastmap WL pool size: %d",
976 ubi->fm_wl_pool.max_size);
977 #else
978 ubi->fm_disabled = 1;
979 #endif
980 mutex_init(&ubi->buf_mutex);
981 mutex_init(&ubi->ckvol_mutex);
982 mutex_init(&ubi->device_mutex);
983 spin_lock_init(&ubi->volumes_lock);
984 init_rwsem(&ubi->fm_protect);
985 init_rwsem(&ubi->fm_eba_sem);
986
987 ubi_msg(ubi, "attaching mtd%d", mtd->index);
988
989 err = io_init(ubi, max_beb_per1024);
990 if (err)
991 goto out_free;
992
993 err = -ENOMEM;
994 ubi->peb_buf = vmalloc(ubi->peb_size);
995 if (!ubi->peb_buf)
996 goto out_free;
997
998 #ifdef CONFIG_MTD_UBI_FASTMAP
999 ubi->fm_size = ubi_calc_fm_size(ubi);
1000 ubi->fm_buf = vzalloc(ubi->fm_size);
1001 if (!ubi->fm_buf)
1002 goto out_free;
1003 #endif
1004 err = ubi_attach(ubi, disable_fm ? 1 : 0);
1005 if (err) {
1006 ubi_err(ubi, "failed to attach mtd%d, error %d",
1007 mtd->index, err);
1008 goto out_free;
1009 }
1010
1011 if (ubi->autoresize_vol_id != -1) {
1012 err = autoresize(ubi, ubi->autoresize_vol_id);
1013 if (err)
1014 goto out_detach;
1015 }
1016
1017 err = uif_init(ubi);
1018 if (err)
1019 goto out_detach;
1020
1021 err = ubi_debugfs_init_dev(ubi);
1022 if (err)
1023 goto out_uif;
1024
1025 ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
1026 if (IS_ERR(ubi->bgt_thread)) {
1027 err = PTR_ERR(ubi->bgt_thread);
1028 ubi_err(ubi, "cannot spawn \"%s\", error %d",
1029 ubi->bgt_name, err);
1030 goto out_debugfs;
1031 }
1032
1033 ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
1034 mtd->index, mtd->name, ubi->flash_size >> 20);
1035 ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
1036 ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
1037 ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
1038 ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
1039 ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
1040 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
1041 ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
1042 ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
1043 ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
1044 ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
1045 ubi->vtbl_slots);
1046 ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
1047 ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
1048 ubi->image_seq);
1049 ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
1050 ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
1051
1052 /*
1053 * The below lock makes sure we do not race with 'ubi_thread()' which
1054 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1055 */
1056 spin_lock(&ubi->wl_lock);
1057 ubi->thread_enabled = 1;
1058 wake_up_process(ubi->bgt_thread);
1059 spin_unlock(&ubi->wl_lock);
1060
1061 ubi_devices[ubi_num] = ubi;
1062 ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1063 return ubi_num;
1064
1065 out_debugfs:
1066 ubi_debugfs_exit_dev(ubi);
1067 out_uif:
1068 uif_close(ubi);
1069 out_detach:
1070 ubi_wl_close(ubi);
1071 ubi_free_all_volumes(ubi);
1072 vfree(ubi->vtbl);
1073 out_free:
1074 vfree(ubi->peb_buf);
1075 vfree(ubi->fm_buf);
1076 put_device(&ubi->dev);
1077 return err;
1078 }
1079
1080 /**
1081 * ubi_detach_mtd_dev - detach an MTD device.
1082 * @ubi_num: UBI device number to detach from
1083 * @anyway: detach MTD even if device reference count is not zero
1084 *
1085 * This function destroys an UBI device number @ubi_num and detaches the
1086 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1087 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1088 * exist.
1089 *
1090 * Note, the invocations of this function has to be serialized by the
1091 * @ubi_devices_mutex.
1092 */
ubi_detach_mtd_dev(int ubi_num,int anyway)1093 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1094 {
1095 struct ubi_device *ubi;
1096
1097 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1098 return -EINVAL;
1099
1100 ubi = ubi_get_device(ubi_num);
1101 if (!ubi)
1102 return -EINVAL;
1103
1104 spin_lock(&ubi_devices_lock);
1105 ubi->ref_count -= 1;
1106 if (ubi->ref_count) {
1107 if (!anyway) {
1108 spin_unlock(&ubi_devices_lock);
1109 return -EBUSY;
1110 }
1111 /* This may only happen if there is a bug */
1112 ubi_err(ubi, "%s reference count %d, destroy anyway",
1113 ubi->ubi_name, ubi->ref_count);
1114 }
1115 ubi->is_dead = true;
1116 spin_unlock(&ubi_devices_lock);
1117
1118 ubi_notify_all(ubi, UBI_VOLUME_SHUTDOWN, NULL);
1119
1120 spin_lock(&ubi_devices_lock);
1121 put_device(&ubi->dev);
1122 ubi_devices[ubi_num] = NULL;
1123 spin_unlock(&ubi_devices_lock);
1124
1125 ubi_assert(ubi_num == ubi->ubi_num);
1126 ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1127 ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
1128 #ifdef CONFIG_MTD_UBI_FASTMAP
1129 /* If we don't write a new fastmap at detach time we lose all
1130 * EC updates that have been made since the last written fastmap.
1131 * In case of fastmap debugging we omit the update to simulate an
1132 * unclean shutdown. */
1133 if (!ubi_dbg_chk_fastmap(ubi))
1134 ubi_update_fastmap(ubi);
1135 #endif
1136 /*
1137 * Before freeing anything, we have to stop the background thread to
1138 * prevent it from doing anything on this device while we are freeing.
1139 */
1140 if (ubi->bgt_thread)
1141 kthread_stop(ubi->bgt_thread);
1142
1143 #ifdef CONFIG_MTD_UBI_FASTMAP
1144 cancel_work_sync(&ubi->fm_work);
1145 #endif
1146 ubi_debugfs_exit_dev(ubi);
1147 uif_close(ubi);
1148
1149 ubi_wl_close(ubi);
1150 ubi_free_internal_volumes(ubi);
1151 vfree(ubi->vtbl);
1152 vfree(ubi->peb_buf);
1153 vfree(ubi->fm_buf);
1154 ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1155 put_mtd_device(ubi->mtd);
1156 put_device(&ubi->dev);
1157 return 0;
1158 }
1159
1160 /**
1161 * open_mtd_by_chdev - open an MTD device by its character device node path.
1162 * @mtd_dev: MTD character device node path
1163 *
1164 * This helper function opens an MTD device by its character node device path.
1165 * Returns MTD device description object in case of success and a negative
1166 * error code in case of failure.
1167 */
open_mtd_by_chdev(const char * mtd_dev)1168 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1169 {
1170 int err, minor;
1171 struct path path;
1172 struct kstat stat;
1173
1174 /* Probably this is an MTD character device node path */
1175 err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1176 if (err)
1177 return ERR_PTR(err);
1178
1179 err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
1180 path_put(&path);
1181 if (err)
1182 return ERR_PTR(err);
1183
1184 /* MTD device number is defined by the major / minor numbers */
1185 if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))
1186 return ERR_PTR(-EINVAL);
1187
1188 minor = MINOR(stat.rdev);
1189
1190 if (minor & 1)
1191 /*
1192 * Just do not think the "/dev/mtdrX" devices support is need,
1193 * so do not support them to avoid doing extra work.
1194 */
1195 return ERR_PTR(-EINVAL);
1196
1197 return get_mtd_device(NULL, minor / 2);
1198 }
1199
1200 /**
1201 * open_mtd_device - open MTD device by name, character device path, or number.
1202 * @mtd_dev: name, character device node path, or MTD device device number
1203 *
1204 * This function tries to open and MTD device described by @mtd_dev string,
1205 * which is first treated as ASCII MTD device number, and if it is not true, it
1206 * is treated as MTD device name, and if that is also not true, it is treated
1207 * as MTD character device node path. Returns MTD device description object in
1208 * case of success and a negative error code in case of failure.
1209 */
open_mtd_device(const char * mtd_dev)1210 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1211 {
1212 struct mtd_info *mtd;
1213 int mtd_num;
1214 char *endp;
1215
1216 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1217 if (*endp != '\0' || mtd_dev == endp) {
1218 /*
1219 * This does not look like an ASCII integer, probably this is
1220 * MTD device name.
1221 */
1222 mtd = get_mtd_device_nm(mtd_dev);
1223 if (PTR_ERR(mtd) == -ENODEV)
1224 /* Probably this is an MTD character device node path */
1225 mtd = open_mtd_by_chdev(mtd_dev);
1226 } else
1227 mtd = get_mtd_device(NULL, mtd_num);
1228
1229 return mtd;
1230 }
1231
ubi_notify_add(struct mtd_info * mtd)1232 static void ubi_notify_add(struct mtd_info *mtd)
1233 {
1234 struct device_node *np = mtd_get_of_node(mtd);
1235 int err;
1236
1237 if (!of_device_is_compatible(np, "linux,ubi"))
1238 return;
1239
1240 /*
1241 * we are already holding &mtd_table_mutex, but still need
1242 * to bump refcount
1243 */
1244 err = __get_mtd_device(mtd);
1245 if (err)
1246 return;
1247
1248 /* called while holding mtd_table_mutex */
1249 mutex_lock_nested(&ubi_devices_mutex, SINGLE_DEPTH_NESTING);
1250 err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO, 0, 0, false, false);
1251 mutex_unlock(&ubi_devices_mutex);
1252 if (err < 0)
1253 __put_mtd_device(mtd);
1254 }
1255
ubi_notify_remove(struct mtd_info * mtd)1256 static void ubi_notify_remove(struct mtd_info *mtd)
1257 {
1258 /* do nothing for now */
1259 }
1260
1261 static struct mtd_notifier ubi_mtd_notifier = {
1262 .add = ubi_notify_add,
1263 .remove = ubi_notify_remove,
1264 };
1265
ubi_init_attach(void)1266 static int __init ubi_init_attach(void)
1267 {
1268 int err, i, k;
1269
1270 /* Attach MTD devices */
1271 for (i = 0; i < mtd_devs; i++) {
1272 struct mtd_dev_param *p = &mtd_dev_param[i];
1273 struct mtd_info *mtd;
1274
1275 cond_resched();
1276
1277 mtd = open_mtd_device(p->name);
1278 if (IS_ERR(mtd)) {
1279 err = PTR_ERR(mtd);
1280 pr_err("UBI error: cannot open mtd %s, error %d\n",
1281 p->name, err);
1282 /* See comment below re-ubi_is_module(). */
1283 if (ubi_is_module())
1284 goto out_detach;
1285 continue;
1286 }
1287
1288 mutex_lock(&ubi_devices_mutex);
1289 err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1290 p->vid_hdr_offs, p->max_beb_per1024,
1291 p->enable_fm == 0,
1292 p->need_resv_pool != 0);
1293 mutex_unlock(&ubi_devices_mutex);
1294 if (err < 0) {
1295 pr_err("UBI error: cannot attach mtd%d\n",
1296 mtd->index);
1297 put_mtd_device(mtd);
1298
1299 /*
1300 * Originally UBI stopped initializing on any error.
1301 * However, later on it was found out that this
1302 * behavior is not very good when UBI is compiled into
1303 * the kernel and the MTD devices to attach are passed
1304 * through the command line. Indeed, UBI failure
1305 * stopped whole boot sequence.
1306 *
1307 * To fix this, we changed the behavior for the
1308 * non-module case, but preserved the old behavior for
1309 * the module case, just for compatibility. This is a
1310 * little inconsistent, though.
1311 */
1312 if (ubi_is_module())
1313 goto out_detach;
1314 }
1315 }
1316
1317 return 0;
1318
1319 out_detach:
1320 for (k = 0; k < i; k++)
1321 if (ubi_devices[k]) {
1322 mutex_lock(&ubi_devices_mutex);
1323 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1324 mutex_unlock(&ubi_devices_mutex);
1325 }
1326 return err;
1327 }
1328 #ifndef CONFIG_MTD_UBI_MODULE
1329 late_initcall(ubi_init_attach);
1330 #endif
1331
ubi_init(void)1332 static int __init ubi_init(void)
1333 {
1334 int err;
1335
1336 /* Ensure that EC and VID headers have correct size */
1337 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1338 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1339
1340 if (mtd_devs > UBI_MAX_DEVICES) {
1341 pr_err("UBI error: too many MTD devices, maximum is %d\n",
1342 UBI_MAX_DEVICES);
1343 return -EINVAL;
1344 }
1345
1346 /* Create base sysfs directory and sysfs files */
1347 err = class_register(&ubi_class);
1348 if (err < 0)
1349 return err;
1350
1351 err = misc_register(&ubi_ctrl_cdev);
1352 if (err) {
1353 pr_err("UBI error: cannot register device\n");
1354 goto out;
1355 }
1356
1357 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1358 sizeof(struct ubi_wl_entry),
1359 0, 0, NULL);
1360 if (!ubi_wl_entry_slab) {
1361 err = -ENOMEM;
1362 goto out_dev_unreg;
1363 }
1364
1365 err = ubi_debugfs_init();
1366 if (err)
1367 goto out_slab;
1368
1369 err = ubiblock_init();
1370 if (err) {
1371 pr_err("UBI error: block: cannot initialize, error %d\n", err);
1372
1373 /* See comment above re-ubi_is_module(). */
1374 if (ubi_is_module())
1375 goto out_debugfs;
1376 }
1377
1378 register_mtd_user(&ubi_mtd_notifier);
1379
1380 if (ubi_is_module()) {
1381 err = ubi_init_attach();
1382 if (err)
1383 goto out_mtd_notifier;
1384 }
1385
1386 return 0;
1387
1388 out_mtd_notifier:
1389 unregister_mtd_user(&ubi_mtd_notifier);
1390 ubiblock_exit();
1391 out_debugfs:
1392 ubi_debugfs_exit();
1393 out_slab:
1394 kmem_cache_destroy(ubi_wl_entry_slab);
1395 out_dev_unreg:
1396 misc_deregister(&ubi_ctrl_cdev);
1397 out:
1398 class_unregister(&ubi_class);
1399 pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1400 return err;
1401 }
1402 device_initcall(ubi_init);
1403
1404
ubi_exit(void)1405 static void __exit ubi_exit(void)
1406 {
1407 int i;
1408
1409 ubiblock_exit();
1410 unregister_mtd_user(&ubi_mtd_notifier);
1411
1412 for (i = 0; i < UBI_MAX_DEVICES; i++)
1413 if (ubi_devices[i]) {
1414 mutex_lock(&ubi_devices_mutex);
1415 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1416 mutex_unlock(&ubi_devices_mutex);
1417 }
1418 ubi_debugfs_exit();
1419 kmem_cache_destroy(ubi_wl_entry_slab);
1420 misc_deregister(&ubi_ctrl_cdev);
1421 class_unregister(&ubi_class);
1422 }
1423 module_exit(ubi_exit);
1424
1425 /**
1426 * bytes_str_to_int - convert a number of bytes string into an integer.
1427 * @str: the string to convert
1428 *
1429 * This function returns positive resulting integer in case of success and a
1430 * negative error code in case of failure.
1431 */
bytes_str_to_int(const char * str)1432 static int bytes_str_to_int(const char *str)
1433 {
1434 char *endp;
1435 unsigned long result;
1436
1437 result = simple_strtoul(str, &endp, 0);
1438 if (str == endp || result >= INT_MAX) {
1439 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1440 return -EINVAL;
1441 }
1442
1443 switch (*endp) {
1444 case 'G':
1445 result *= 1024;
1446 fallthrough;
1447 case 'M':
1448 result *= 1024;
1449 fallthrough;
1450 case 'K':
1451 result *= 1024;
1452 break;
1453 case '\0':
1454 break;
1455 default:
1456 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1457 return -EINVAL;
1458 }
1459
1460 return result;
1461 }
1462
1463 /**
1464 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1465 * @val: the parameter value to parse
1466 * @kp: not used
1467 *
1468 * This function returns zero in case of success and a negative error code in
1469 * case of error.
1470 */
ubi_mtd_param_parse(const char * val,const struct kernel_param * kp)1471 static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp)
1472 {
1473 int i, len;
1474 struct mtd_dev_param *p;
1475 char buf[MTD_PARAM_LEN_MAX];
1476 char *pbuf = &buf[0];
1477 char *tokens[MTD_PARAM_MAX_COUNT], *token;
1478
1479 if (!val)
1480 return -EINVAL;
1481
1482 if (mtd_devs == UBI_MAX_DEVICES) {
1483 pr_err("UBI error: too many parameters, max. is %d\n",
1484 UBI_MAX_DEVICES);
1485 return -EINVAL;
1486 }
1487
1488 len = strnlen(val, MTD_PARAM_LEN_MAX);
1489 if (len == MTD_PARAM_LEN_MAX) {
1490 pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1491 val, MTD_PARAM_LEN_MAX);
1492 return -EINVAL;
1493 }
1494
1495 if (len == 0) {
1496 pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1497 return 0;
1498 }
1499
1500 strcpy(buf, val);
1501
1502 /* Get rid of the final newline */
1503 if (buf[len - 1] == '\n')
1504 buf[len - 1] = '\0';
1505
1506 for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1507 tokens[i] = strsep(&pbuf, ",");
1508
1509 if (pbuf) {
1510 pr_err("UBI error: too many arguments at \"%s\"\n", val);
1511 return -EINVAL;
1512 }
1513
1514 p = &mtd_dev_param[mtd_devs];
1515 strcpy(&p->name[0], tokens[0]);
1516
1517 token = tokens[1];
1518 if (token) {
1519 p->vid_hdr_offs = bytes_str_to_int(token);
1520
1521 if (p->vid_hdr_offs < 0)
1522 return p->vid_hdr_offs;
1523 }
1524
1525 token = tokens[2];
1526 if (token) {
1527 int err = kstrtoint(token, 10, &p->max_beb_per1024);
1528
1529 if (err) {
1530 pr_err("UBI error: bad value for max_beb_per1024 parameter: %s\n",
1531 token);
1532 return -EINVAL;
1533 }
1534 }
1535
1536 token = tokens[3];
1537 if (token) {
1538 int err = kstrtoint(token, 10, &p->ubi_num);
1539
1540 if (err) {
1541 pr_err("UBI error: bad value for ubi_num parameter: %s\n",
1542 token);
1543 return -EINVAL;
1544 }
1545 } else
1546 p->ubi_num = UBI_DEV_NUM_AUTO;
1547
1548 token = tokens[4];
1549 if (token) {
1550 int err = kstrtoint(token, 10, &p->enable_fm);
1551
1552 if (err) {
1553 pr_err("UBI error: bad value for enable_fm parameter: %s\n",
1554 token);
1555 return -EINVAL;
1556 }
1557 } else
1558 p->enable_fm = 0;
1559
1560 token = tokens[5];
1561 if (token) {
1562 int err = kstrtoint(token, 10, &p->need_resv_pool);
1563
1564 if (err) {
1565 pr_err("UBI error: bad value for need_resv_pool parameter: %s\n",
1566 token);
1567 return -EINVAL;
1568 }
1569 } else
1570 p->need_resv_pool = 0;
1571
1572 mtd_devs += 1;
1573 return 0;
1574 }
1575
1576 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 0400);
1577 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1578 "Multiple \"mtd\" parameters may be specified.\n"
1579 "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1580 "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1581 "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1582 __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1583 "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1584 "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"
1585 "Optional \"need_resv_pool\" parameter determines whether to reserve pool->max_size pebs during attach. If the value is non-zero, peb reservation is enabled. Default value is 0.\n"
1586 "\n"
1587 "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1588 "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"
1589 "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"
1590 "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"
1591 "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"
1592 "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1593 #ifdef CONFIG_MTD_UBI_FASTMAP
1594 module_param(fm_autoconvert, bool, 0644);
1595 MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1596 module_param(fm_debug, bool, 0);
1597 MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1598 #endif
1599 MODULE_VERSION(__stringify(UBI_VERSION));
1600 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1601 MODULE_AUTHOR("Artem Bityutskiy");
1602 MODULE_LICENSE("GPL");
1603