1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (c) International Business Machines Corp., 2006
4 * Copyright (c) Nokia Corporation, 2007
6 * Author: Artem Bityutskiy (Битюцкий Артём),
11 * This file includes UBI initialization and building of UBI devices.
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".
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>
34 /* Maximum length of the 'mtd=' parameter */
35 #define MTD_PARAM_LEN_MAX 64
37 /* Maximum number of comma-separated items in the 'mtd=' parameter */
38 #define MTD_PARAM_MAX_COUNT 4
40 /* Maximum value for the number of bad PEBs per 1024 PEBs */
41 #define MAX_MTD_UBI_BEB_LIMIT 768
43 #ifdef CONFIG_MTD_UBI_MODULE
44 #define ubi_is_module() 1
46 #define ubi_is_module() 0
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
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
57 struct mtd_dev_param {
58 char name[MTD_PARAM_LEN_MAX];
64 /* Numbers of elements set in the @mtd_dev_param array */
67 /* MTD devices specification parameters */
68 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
69 #ifdef CONFIG_MTD_UBI_FASTMAP
70 /* UBI module parameter to enable fastmap automatically on non-fastmap images */
71 static bool fm_autoconvert;
75 /* Slab cache for wear-leveling entries */
76 struct kmem_cache *ubi_wl_entry_slab;
78 /* UBI control character device */
79 static struct miscdevice ubi_ctrl_cdev = {
80 .minor = MISC_DYNAMIC_MINOR,
82 .fops = &ubi_ctrl_cdev_operations,
85 /* All UBI devices in system */
86 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
88 /* Serializes UBI devices creations and removals */
89 DEFINE_MUTEX(ubi_devices_mutex);
91 /* Protects @ubi_devices and @ubi->ref_count */
92 static DEFINE_SPINLOCK(ubi_devices_lock);
94 /* "Show" method for files in '/<sysfs>/class/ubi/' */
95 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
96 static ssize_t version_show(struct class *class, struct class_attribute *attr,
99 return sprintf(buf, "%d\n", UBI_VERSION);
101 static CLASS_ATTR_RO(version);
103 static struct attribute *ubi_class_attrs[] = {
104 &class_attr_version.attr,
107 ATTRIBUTE_GROUPS(ubi_class);
109 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
110 struct class ubi_class = {
111 .name = UBI_NAME_STR,
112 .owner = THIS_MODULE,
113 .class_groups = ubi_class_groups,
116 static ssize_t dev_attribute_show(struct device *dev,
117 struct device_attribute *attr, char *buf);
119 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
120 static struct device_attribute dev_eraseblock_size =
121 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
122 static struct device_attribute dev_avail_eraseblocks =
123 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
124 static struct device_attribute dev_total_eraseblocks =
125 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
126 static struct device_attribute dev_volumes_count =
127 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
128 static struct device_attribute dev_max_ec =
129 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
130 static struct device_attribute dev_reserved_for_bad =
131 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
132 static struct device_attribute dev_bad_peb_count =
133 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
134 static struct device_attribute dev_max_vol_count =
135 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
136 static struct device_attribute dev_min_io_size =
137 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
138 static struct device_attribute dev_bgt_enabled =
139 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
140 static struct device_attribute dev_mtd_num =
141 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
142 static struct device_attribute dev_ro_mode =
143 __ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
146 * ubi_volume_notify - send a volume change notification.
147 * @ubi: UBI device description object
148 * @vol: volume description object of the changed volume
149 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
151 * This is a helper function which notifies all subscribers about a volume
152 * change event (creation, removal, re-sizing, re-naming, updating). Returns
153 * zero in case of success and a negative error code in case of failure.
155 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
158 struct ubi_notification nt;
160 ubi_do_get_device_info(ubi, &nt.di);
161 ubi_do_get_volume_info(ubi, vol, &nt.vi);
164 case UBI_VOLUME_ADDED:
165 case UBI_VOLUME_REMOVED:
166 case UBI_VOLUME_RESIZED:
167 case UBI_VOLUME_RENAMED:
168 ret = ubi_update_fastmap(ubi);
170 ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
173 return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
177 * ubi_notify_all - send a notification to all volumes.
178 * @ubi: UBI device description object
179 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
180 * @nb: the notifier to call
182 * This function walks all volumes of UBI device @ubi and sends the @ntype
183 * notification for each volume. If @nb is %NULL, then all registered notifiers
184 * are called, otherwise only the @nb notifier is called. Returns the number of
185 * sent notifications.
187 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
189 struct ubi_notification nt;
192 ubi_do_get_device_info(ubi, &nt.di);
194 mutex_lock(&ubi->device_mutex);
195 for (i = 0; i < ubi->vtbl_slots; i++) {
197 * Since the @ubi->device is locked, and we are not going to
198 * change @ubi->volumes, we do not have to lock
199 * @ubi->volumes_lock.
201 if (!ubi->volumes[i])
204 ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
206 nb->notifier_call(nb, ntype, &nt);
208 blocking_notifier_call_chain(&ubi_notifiers, ntype,
212 mutex_unlock(&ubi->device_mutex);
218 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
219 * @nb: the notifier to call
221 * This function walks all UBI devices and volumes and sends the
222 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
223 * registered notifiers are called, otherwise only the @nb notifier is called.
224 * Returns the number of sent notifications.
226 int ubi_enumerate_volumes(struct notifier_block *nb)
231 * Since the @ubi_devices_mutex is locked, and we are not going to
232 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
234 for (i = 0; i < UBI_MAX_DEVICES; i++) {
235 struct ubi_device *ubi = ubi_devices[i];
239 count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
246 * ubi_get_device - get UBI device.
247 * @ubi_num: UBI device number
249 * This function returns UBI device description object for UBI device number
250 * @ubi_num, or %NULL if the device does not exist. This function increases the
251 * device reference count to prevent removal of the device. In other words, the
252 * device cannot be removed if its reference count is not zero.
254 struct ubi_device *ubi_get_device(int ubi_num)
256 struct ubi_device *ubi;
258 spin_lock(&ubi_devices_lock);
259 ubi = ubi_devices[ubi_num];
261 ubi_assert(ubi->ref_count >= 0);
263 get_device(&ubi->dev);
265 spin_unlock(&ubi_devices_lock);
271 * ubi_put_device - drop an UBI device reference.
272 * @ubi: UBI device description object
274 void ubi_put_device(struct ubi_device *ubi)
276 spin_lock(&ubi_devices_lock);
278 put_device(&ubi->dev);
279 spin_unlock(&ubi_devices_lock);
283 * ubi_get_by_major - get UBI device by character device major number.
284 * @major: major number
286 * This function is similar to 'ubi_get_device()', but it searches the device
287 * by its major number.
289 struct ubi_device *ubi_get_by_major(int major)
292 struct ubi_device *ubi;
294 spin_lock(&ubi_devices_lock);
295 for (i = 0; i < UBI_MAX_DEVICES; i++) {
296 ubi = ubi_devices[i];
297 if (ubi && MAJOR(ubi->cdev.dev) == major) {
298 ubi_assert(ubi->ref_count >= 0);
300 get_device(&ubi->dev);
301 spin_unlock(&ubi_devices_lock);
305 spin_unlock(&ubi_devices_lock);
311 * ubi_major2num - get UBI device number by character device major number.
312 * @major: major number
314 * This function searches UBI device number object by its major number. If UBI
315 * device was not found, this function returns -ENODEV, otherwise the UBI device
316 * number is returned.
318 int ubi_major2num(int major)
320 int i, ubi_num = -ENODEV;
322 spin_lock(&ubi_devices_lock);
323 for (i = 0; i < UBI_MAX_DEVICES; i++) {
324 struct ubi_device *ubi = ubi_devices[i];
326 if (ubi && MAJOR(ubi->cdev.dev) == major) {
327 ubi_num = ubi->ubi_num;
331 spin_unlock(&ubi_devices_lock);
336 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
337 static ssize_t dev_attribute_show(struct device *dev,
338 struct device_attribute *attr, char *buf)
341 struct ubi_device *ubi;
344 * The below code looks weird, but it actually makes sense. We get the
345 * UBI device reference from the contained 'struct ubi_device'. But it
346 * is unclear if the device was removed or not yet. Indeed, if the
347 * device was removed before we increased its reference count,
348 * 'ubi_get_device()' will return -ENODEV and we fail.
350 * Remember, 'struct ubi_device' is freed in the release function, so
351 * we still can use 'ubi->ubi_num'.
353 ubi = container_of(dev, struct ubi_device, dev);
355 if (attr == &dev_eraseblock_size)
356 ret = sprintf(buf, "%d\n", ubi->leb_size);
357 else if (attr == &dev_avail_eraseblocks)
358 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
359 else if (attr == &dev_total_eraseblocks)
360 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
361 else if (attr == &dev_volumes_count)
362 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
363 else if (attr == &dev_max_ec)
364 ret = sprintf(buf, "%d\n", ubi->max_ec);
365 else if (attr == &dev_reserved_for_bad)
366 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
367 else if (attr == &dev_bad_peb_count)
368 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
369 else if (attr == &dev_max_vol_count)
370 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
371 else if (attr == &dev_min_io_size)
372 ret = sprintf(buf, "%d\n", ubi->min_io_size);
373 else if (attr == &dev_bgt_enabled)
374 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
375 else if (attr == &dev_mtd_num)
376 ret = sprintf(buf, "%d\n", ubi->mtd->index);
377 else if (attr == &dev_ro_mode)
378 ret = sprintf(buf, "%d\n", ubi->ro_mode);
385 static struct attribute *ubi_dev_attrs[] = {
386 &dev_eraseblock_size.attr,
387 &dev_avail_eraseblocks.attr,
388 &dev_total_eraseblocks.attr,
389 &dev_volumes_count.attr,
391 &dev_reserved_for_bad.attr,
392 &dev_bad_peb_count.attr,
393 &dev_max_vol_count.attr,
394 &dev_min_io_size.attr,
395 &dev_bgt_enabled.attr,
400 ATTRIBUTE_GROUPS(ubi_dev);
402 static void dev_release(struct device *dev)
404 struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
410 * kill_volumes - destroy all user volumes.
411 * @ubi: UBI device description object
413 static void kill_volumes(struct ubi_device *ubi)
417 for (i = 0; i < ubi->vtbl_slots; i++)
419 ubi_free_volume(ubi, ubi->volumes[i]);
423 * uif_init - initialize user interfaces for an UBI device.
424 * @ubi: UBI device description object
426 * This function initializes various user interfaces for an UBI device. If the
427 * initialization fails at an early stage, this function frees all the
428 * resources it allocated, returns an error.
430 * This function returns zero in case of success and a negative error code in
433 static int uif_init(struct ubi_device *ubi)
438 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
441 * Major numbers for the UBI character devices are allocated
442 * dynamically. Major numbers of volume character devices are
443 * equivalent to ones of the corresponding UBI character device. Minor
444 * numbers of UBI character devices are 0, while minor numbers of
445 * volume character devices start from 1. Thus, we allocate one major
446 * number and ubi->vtbl_slots + 1 minor numbers.
448 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
450 ubi_err(ubi, "cannot register UBI character devices");
456 ubi_assert(MINOR(dev) == 0);
457 cdev_init(&ubi->cdev, &ubi_cdev_operations);
458 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
459 ubi->cdev.owner = THIS_MODULE;
461 dev_set_name(&ubi->dev, UBI_NAME_STR "%d", ubi->ubi_num);
462 err = cdev_device_add(&ubi->cdev, &ubi->dev);
466 for (i = 0; i < ubi->vtbl_slots; i++)
467 if (ubi->volumes[i]) {
468 err = ubi_add_volume(ubi, ubi->volumes[i]);
470 ubi_err(ubi, "cannot add volume %d", i);
479 cdev_device_del(&ubi->cdev, &ubi->dev);
481 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
482 ubi_err(ubi, "cannot initialize UBI %s, error %d",
488 * uif_close - close user interfaces for an UBI device.
489 * @ubi: UBI device description object
491 * Note, since this function un-registers UBI volume device objects (@vol->dev),
492 * the memory allocated voe the volumes is freed as well (in the release
495 static void uif_close(struct ubi_device *ubi)
498 cdev_device_del(&ubi->cdev, &ubi->dev);
499 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
503 * ubi_free_volumes_from - free volumes from specific index.
504 * @ubi: UBI device description object
505 * @from: the start index used for volume free.
507 static void ubi_free_volumes_from(struct ubi_device *ubi, int from)
511 for (i = from; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
512 if (!ubi->volumes[i])
514 ubi_eba_replace_table(ubi->volumes[i], NULL);
515 ubi_fastmap_destroy_checkmap(ubi->volumes[i]);
516 kfree(ubi->volumes[i]);
517 ubi->volumes[i] = NULL;
522 * ubi_free_all_volumes - free all volumes.
523 * @ubi: UBI device description object
525 void ubi_free_all_volumes(struct ubi_device *ubi)
527 ubi_free_volumes_from(ubi, 0);
531 * ubi_free_internal_volumes - free internal volumes.
532 * @ubi: UBI device description object
534 void ubi_free_internal_volumes(struct ubi_device *ubi)
536 ubi_free_volumes_from(ubi, ubi->vtbl_slots);
539 static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
541 int limit, device_pebs;
542 uint64_t device_size;
544 if (!max_beb_per1024) {
546 * Since max_beb_per1024 has not been set by the user in either
547 * the cmdline or Kconfig, use mtd_max_bad_blocks to set the
548 * limit if it is supported by the device.
550 limit = mtd_max_bad_blocks(ubi->mtd, 0, ubi->mtd->size);
557 * Here we are using size of the entire flash chip and
558 * not just the MTD partition size because the maximum
559 * number of bad eraseblocks is a percentage of the
560 * whole device and bad eraseblocks are not fairly
561 * distributed over the flash chip. So the worst case
562 * is that all the bad eraseblocks of the chip are in
563 * the MTD partition we are attaching (ubi->mtd).
565 device_size = mtd_get_device_size(ubi->mtd);
566 device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
567 limit = mult_frac(device_pebs, max_beb_per1024, 1024);
570 if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
577 * io_init - initialize I/O sub-system for a given UBI device.
578 * @ubi: UBI device description object
579 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
581 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
583 * o EC header is always at offset zero - this cannot be changed;
584 * o VID header starts just after the EC header at the closest address
585 * aligned to @io->hdrs_min_io_size;
586 * o data starts just after the VID header at the closest address aligned to
589 * This function returns zero in case of success and a negative error code in
592 static int io_init(struct ubi_device *ubi, int max_beb_per1024)
594 dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
595 dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
597 if (ubi->mtd->numeraseregions != 0) {
599 * Some flashes have several erase regions. Different regions
600 * may have different eraseblock size and other
601 * characteristics. It looks like mostly multi-region flashes
602 * have one "main" region and one or more small regions to
603 * store boot loader code or boot parameters or whatever. I
604 * guess we should just pick the largest region. But this is
607 ubi_err(ubi, "multiple regions, not implemented");
611 if (ubi->vid_hdr_offset < 0)
615 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
616 * physical eraseblocks maximum.
619 ubi->peb_size = ubi->mtd->erasesize;
620 ubi->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
621 ubi->flash_size = ubi->mtd->size;
623 if (mtd_can_have_bb(ubi->mtd)) {
624 ubi->bad_allowed = 1;
625 ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
628 if (ubi->mtd->type == MTD_NORFLASH)
631 ubi->min_io_size = ubi->mtd->writesize;
632 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
635 * Make sure minimal I/O unit is power of 2. Note, there is no
636 * fundamental reason for this assumption. It is just an optimization
637 * which allows us to avoid costly division operations.
639 if (!is_power_of_2(ubi->min_io_size)) {
640 ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
645 ubi_assert(ubi->hdrs_min_io_size > 0);
646 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
647 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
649 ubi->max_write_size = ubi->mtd->writebufsize;
651 * Maximum write size has to be greater or equivalent to min. I/O
652 * size, and be multiple of min. I/O size.
654 if (ubi->max_write_size < ubi->min_io_size ||
655 ubi->max_write_size % ubi->min_io_size ||
656 !is_power_of_2(ubi->max_write_size)) {
657 ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
658 ubi->max_write_size, ubi->min_io_size);
662 /* Calculate default aligned sizes of EC and VID headers */
663 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
664 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
666 dbg_gen("min_io_size %d", ubi->min_io_size);
667 dbg_gen("max_write_size %d", ubi->max_write_size);
668 dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
669 dbg_gen("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
670 dbg_gen("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
672 if (ubi->vid_hdr_offset == 0)
674 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
677 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
678 ~(ubi->hdrs_min_io_size - 1);
679 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
680 ubi->vid_hdr_aloffset;
683 /* Similar for the data offset */
684 ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
685 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
687 dbg_gen("vid_hdr_offset %d", ubi->vid_hdr_offset);
688 dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
689 dbg_gen("vid_hdr_shift %d", ubi->vid_hdr_shift);
690 dbg_gen("leb_start %d", ubi->leb_start);
692 /* The shift must be aligned to 32-bit boundary */
693 if (ubi->vid_hdr_shift % 4) {
694 ubi_err(ubi, "unaligned VID header shift %d",
700 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
701 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
702 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
703 ubi->leb_start & (ubi->min_io_size - 1)) {
704 ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
705 ubi->vid_hdr_offset, ubi->leb_start);
710 * Set maximum amount of physical erroneous eraseblocks to be 10%.
711 * Erroneous PEB are those which have read errors.
713 ubi->max_erroneous = ubi->peb_count / 10;
714 if (ubi->max_erroneous < 16)
715 ubi->max_erroneous = 16;
716 dbg_gen("max_erroneous %d", ubi->max_erroneous);
719 * It may happen that EC and VID headers are situated in one minimal
720 * I/O unit. In this case we can only accept this UBI image in
723 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
724 ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
728 ubi->leb_size = ubi->peb_size - ubi->leb_start;
730 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
731 ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
737 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
738 * unfortunately, MTD does not provide this information. We should loop
739 * over all physical eraseblocks and invoke mtd->block_is_bad() for
740 * each physical eraseblock. So, we leave @ubi->bad_peb_count
741 * uninitialized so far.
748 * autoresize - re-size the volume which has the "auto-resize" flag set.
749 * @ubi: UBI device description object
750 * @vol_id: ID of the volume to re-size
752 * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
753 * the volume table to the largest possible size. See comments in ubi-header.h
754 * for more description of the flag. Returns zero in case of success and a
755 * negative error code in case of failure.
757 static int autoresize(struct ubi_device *ubi, int vol_id)
759 struct ubi_volume_desc desc;
760 struct ubi_volume *vol = ubi->volumes[vol_id];
761 int err, old_reserved_pebs = vol->reserved_pebs;
764 ubi_warn(ubi, "skip auto-resize because of R/O mode");
769 * Clear the auto-resize flag in the volume in-memory copy of the
770 * volume table, and 'ubi_resize_volume()' will propagate this change
773 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
775 if (ubi->avail_pebs == 0) {
776 struct ubi_vtbl_record vtbl_rec;
779 * No available PEBs to re-size the volume, clear the flag on
782 vtbl_rec = ubi->vtbl[vol_id];
783 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
785 ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
789 err = ubi_resize_volume(&desc,
790 old_reserved_pebs + ubi->avail_pebs);
792 ubi_err(ubi, "cannot auto-resize volume %d",
799 ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
800 vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
805 * ubi_attach_mtd_dev - attach an MTD device.
806 * @mtd: MTD device description object
807 * @ubi_num: number to assign to the new UBI device
808 * @vid_hdr_offset: VID header offset
809 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
811 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
812 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
813 * which case this function finds a vacant device number and assigns it
814 * automatically. Returns the new UBI device number in case of success and a
815 * negative error code in case of failure.
817 * Note, the invocations of this function has to be serialized by the
818 * @ubi_devices_mutex.
820 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
821 int vid_hdr_offset, int max_beb_per1024)
823 struct ubi_device *ubi;
826 if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
829 if (!max_beb_per1024)
830 max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
833 * Check if we already have the same MTD device attached.
835 * Note, this function assumes that UBI devices creations and deletions
836 * are serialized, so it does not take the &ubi_devices_lock.
838 for (i = 0; i < UBI_MAX_DEVICES; i++) {
839 ubi = ubi_devices[i];
840 if (ubi && mtd->index == ubi->mtd->index) {
841 pr_err("ubi: mtd%d is already attached to ubi%d\n",
848 * Make sure this MTD device is not emulated on top of an UBI volume
849 * already. Well, generally this recursion works fine, but there are
850 * different problems like the UBI module takes a reference to itself
851 * by attaching (and thus, opening) the emulated MTD device. This
852 * results in inability to unload the module. And in general it makes
853 * no sense to attach emulated MTD devices, so we prohibit this.
855 if (mtd->type == MTD_UBIVOLUME) {
856 pr_err("ubi: refuse attaching mtd%d - it is already emulated on top of UBI\n",
862 * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes.
863 * MLC NAND is different and needs special care, otherwise UBI or UBIFS
864 * will die soon and you will lose all your data.
865 * Relax this rule if the partition we're attaching to operates in SLC
868 if (mtd->type == MTD_MLCNANDFLASH &&
869 !(mtd->flags & MTD_SLC_ON_MLC_EMULATION)) {
870 pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n",
875 if (ubi_num == UBI_DEV_NUM_AUTO) {
876 /* Search for an empty slot in the @ubi_devices array */
877 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
878 if (!ubi_devices[ubi_num])
880 if (ubi_num == UBI_MAX_DEVICES) {
881 pr_err("ubi: only %d UBI devices may be created\n",
886 if (ubi_num >= UBI_MAX_DEVICES)
889 /* Make sure ubi_num is not busy */
890 if (ubi_devices[ubi_num]) {
891 pr_err("ubi: ubi%i already exists\n", ubi_num);
896 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
900 device_initialize(&ubi->dev);
901 ubi->dev.release = dev_release;
902 ubi->dev.class = &ubi_class;
903 ubi->dev.groups = ubi_dev_groups;
906 ubi->ubi_num = ubi_num;
907 ubi->vid_hdr_offset = vid_hdr_offset;
908 ubi->autoresize_vol_id = -1;
910 #ifdef CONFIG_MTD_UBI_FASTMAP
911 ubi->fm_pool.used = ubi->fm_pool.size = 0;
912 ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
915 * fm_pool.max_size is 5% of the total number of PEBs but it's also
916 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
918 ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
919 ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
920 ubi->fm_pool.max_size = max(ubi->fm_pool.max_size,
921 UBI_FM_MIN_POOL_SIZE);
923 ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
924 ubi->fm_disabled = !fm_autoconvert;
926 ubi_enable_dbg_chk_fastmap(ubi);
928 if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
929 <= UBI_FM_MAX_START) {
930 ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
932 ubi->fm_disabled = 1;
935 ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
936 ubi_msg(ubi, "default fastmap WL pool size: %d",
937 ubi->fm_wl_pool.max_size);
939 ubi->fm_disabled = 1;
941 mutex_init(&ubi->buf_mutex);
942 mutex_init(&ubi->ckvol_mutex);
943 mutex_init(&ubi->device_mutex);
944 spin_lock_init(&ubi->volumes_lock);
945 init_rwsem(&ubi->fm_protect);
946 init_rwsem(&ubi->fm_eba_sem);
948 ubi_msg(ubi, "attaching mtd%d", mtd->index);
950 err = io_init(ubi, max_beb_per1024);
955 ubi->peb_buf = vmalloc(ubi->peb_size);
959 #ifdef CONFIG_MTD_UBI_FASTMAP
960 ubi->fm_size = ubi_calc_fm_size(ubi);
961 ubi->fm_buf = vzalloc(ubi->fm_size);
965 err = ubi_attach(ubi, 0);
967 ubi_err(ubi, "failed to attach mtd%d, error %d",
972 if (ubi->autoresize_vol_id != -1) {
973 err = autoresize(ubi, ubi->autoresize_vol_id);
982 err = ubi_debugfs_init_dev(ubi);
986 ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
987 if (IS_ERR(ubi->bgt_thread)) {
988 err = PTR_ERR(ubi->bgt_thread);
989 ubi_err(ubi, "cannot spawn \"%s\", error %d",
994 ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
995 mtd->index, mtd->name, ubi->flash_size >> 20);
996 ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
997 ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
998 ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
999 ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
1000 ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
1001 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
1002 ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
1003 ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
1004 ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
1005 ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
1007 ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
1008 ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
1010 ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
1011 ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
1014 * The below lock makes sure we do not race with 'ubi_thread()' which
1015 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1017 spin_lock(&ubi->wl_lock);
1018 ubi->thread_enabled = 1;
1019 wake_up_process(ubi->bgt_thread);
1020 spin_unlock(&ubi->wl_lock);
1022 ubi_devices[ubi_num] = ubi;
1023 ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1027 ubi_debugfs_exit_dev(ubi);
1032 ubi_free_all_volumes(ubi);
1035 vfree(ubi->peb_buf);
1037 put_device(&ubi->dev);
1042 * ubi_detach_mtd_dev - detach an MTD device.
1043 * @ubi_num: UBI device number to detach from
1044 * @anyway: detach MTD even if device reference count is not zero
1046 * This function destroys an UBI device number @ubi_num and detaches the
1047 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1048 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1051 * Note, the invocations of this function has to be serialized by the
1052 * @ubi_devices_mutex.
1054 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1056 struct ubi_device *ubi;
1058 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1061 ubi = ubi_get_device(ubi_num);
1065 spin_lock(&ubi_devices_lock);
1066 put_device(&ubi->dev);
1067 ubi->ref_count -= 1;
1068 if (ubi->ref_count) {
1070 spin_unlock(&ubi_devices_lock);
1073 /* This may only happen if there is a bug */
1074 ubi_err(ubi, "%s reference count %d, destroy anyway",
1075 ubi->ubi_name, ubi->ref_count);
1077 ubi_devices[ubi_num] = NULL;
1078 spin_unlock(&ubi_devices_lock);
1080 ubi_assert(ubi_num == ubi->ubi_num);
1081 ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1082 ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
1083 #ifdef CONFIG_MTD_UBI_FASTMAP
1084 /* If we don't write a new fastmap at detach time we lose all
1085 * EC updates that have been made since the last written fastmap.
1086 * In case of fastmap debugging we omit the update to simulate an
1087 * unclean shutdown. */
1088 if (!ubi_dbg_chk_fastmap(ubi))
1089 ubi_update_fastmap(ubi);
1092 * Before freeing anything, we have to stop the background thread to
1093 * prevent it from doing anything on this device while we are freeing.
1095 if (ubi->bgt_thread)
1096 kthread_stop(ubi->bgt_thread);
1098 #ifdef CONFIG_MTD_UBI_FASTMAP
1099 cancel_work_sync(&ubi->fm_work);
1101 ubi_debugfs_exit_dev(ubi);
1105 ubi_free_internal_volumes(ubi);
1107 vfree(ubi->peb_buf);
1109 ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1110 put_mtd_device(ubi->mtd);
1111 put_device(&ubi->dev);
1116 * open_mtd_by_chdev - open an MTD device by its character device node path.
1117 * @mtd_dev: MTD character device node path
1119 * This helper function opens an MTD device by its character node device path.
1120 * Returns MTD device description object in case of success and a negative
1121 * error code in case of failure.
1123 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1129 /* Probably this is an MTD character device node path */
1130 err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1132 return ERR_PTR(err);
1134 err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
1137 return ERR_PTR(err);
1139 /* MTD device number is defined by the major / minor numbers */
1140 if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))
1141 return ERR_PTR(-EINVAL);
1143 minor = MINOR(stat.rdev);
1147 * Just do not think the "/dev/mtdrX" devices support is need,
1148 * so do not support them to avoid doing extra work.
1150 return ERR_PTR(-EINVAL);
1152 return get_mtd_device(NULL, minor / 2);
1156 * open_mtd_device - open MTD device by name, character device path, or number.
1157 * @mtd_dev: name, character device node path, or MTD device device number
1159 * This function tries to open and MTD device described by @mtd_dev string,
1160 * which is first treated as ASCII MTD device number, and if it is not true, it
1161 * is treated as MTD device name, and if that is also not true, it is treated
1162 * as MTD character device node path. Returns MTD device description object in
1163 * case of success and a negative error code in case of failure.
1165 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1167 struct mtd_info *mtd;
1171 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1172 if (*endp != '\0' || mtd_dev == endp) {
1174 * This does not look like an ASCII integer, probably this is
1177 mtd = get_mtd_device_nm(mtd_dev);
1178 if (PTR_ERR(mtd) == -ENODEV)
1179 /* Probably this is an MTD character device node path */
1180 mtd = open_mtd_by_chdev(mtd_dev);
1182 mtd = get_mtd_device(NULL, mtd_num);
1187 static int __init ubi_init(void)
1191 /* Ensure that EC and VID headers have correct size */
1192 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1193 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1195 if (mtd_devs > UBI_MAX_DEVICES) {
1196 pr_err("UBI error: too many MTD devices, maximum is %d\n",
1201 /* Create base sysfs directory and sysfs files */
1202 err = class_register(&ubi_class);
1206 err = misc_register(&ubi_ctrl_cdev);
1208 pr_err("UBI error: cannot register device\n");
1212 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1213 sizeof(struct ubi_wl_entry),
1215 if (!ubi_wl_entry_slab) {
1220 err = ubi_debugfs_init();
1225 /* Attach MTD devices */
1226 for (i = 0; i < mtd_devs; i++) {
1227 struct mtd_dev_param *p = &mtd_dev_param[i];
1228 struct mtd_info *mtd;
1232 mtd = open_mtd_device(p->name);
1235 pr_err("UBI error: cannot open mtd %s, error %d\n",
1237 /* See comment below re-ubi_is_module(). */
1238 if (ubi_is_module())
1243 mutex_lock(&ubi_devices_mutex);
1244 err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1245 p->vid_hdr_offs, p->max_beb_per1024);
1246 mutex_unlock(&ubi_devices_mutex);
1248 pr_err("UBI error: cannot attach mtd%d\n",
1250 put_mtd_device(mtd);
1253 * Originally UBI stopped initializing on any error.
1254 * However, later on it was found out that this
1255 * behavior is not very good when UBI is compiled into
1256 * the kernel and the MTD devices to attach are passed
1257 * through the command line. Indeed, UBI failure
1258 * stopped whole boot sequence.
1260 * To fix this, we changed the behavior for the
1261 * non-module case, but preserved the old behavior for
1262 * the module case, just for compatibility. This is a
1263 * little inconsistent, though.
1265 if (ubi_is_module())
1270 err = ubiblock_init();
1272 pr_err("UBI error: block: cannot initialize, error %d\n", err);
1274 /* See comment above re-ubi_is_module(). */
1275 if (ubi_is_module())
1282 for (k = 0; k < i; k++)
1283 if (ubi_devices[k]) {
1284 mutex_lock(&ubi_devices_mutex);
1285 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1286 mutex_unlock(&ubi_devices_mutex);
1290 kmem_cache_destroy(ubi_wl_entry_slab);
1292 misc_deregister(&ubi_ctrl_cdev);
1294 class_unregister(&ubi_class);
1295 pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1298 late_initcall(ubi_init);
1300 static void __exit ubi_exit(void)
1306 for (i = 0; i < UBI_MAX_DEVICES; i++)
1307 if (ubi_devices[i]) {
1308 mutex_lock(&ubi_devices_mutex);
1309 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1310 mutex_unlock(&ubi_devices_mutex);
1313 kmem_cache_destroy(ubi_wl_entry_slab);
1314 misc_deregister(&ubi_ctrl_cdev);
1315 class_unregister(&ubi_class);
1317 module_exit(ubi_exit);
1320 * bytes_str_to_int - convert a number of bytes string into an integer.
1321 * @str: the string to convert
1323 * This function returns positive resulting integer in case of success and a
1324 * negative error code in case of failure.
1326 static int bytes_str_to_int(const char *str)
1329 unsigned long result;
1331 result = simple_strtoul(str, &endp, 0);
1332 if (str == endp || result >= INT_MAX) {
1333 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1350 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1358 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1359 * @val: the parameter value to parse
1362 * This function returns zero in case of success and a negative error code in
1365 static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp)
1368 struct mtd_dev_param *p;
1369 char buf[MTD_PARAM_LEN_MAX];
1370 char *pbuf = &buf[0];
1371 char *tokens[MTD_PARAM_MAX_COUNT], *token;
1376 if (mtd_devs == UBI_MAX_DEVICES) {
1377 pr_err("UBI error: too many parameters, max. is %d\n",
1382 len = strnlen(val, MTD_PARAM_LEN_MAX);
1383 if (len == MTD_PARAM_LEN_MAX) {
1384 pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1385 val, MTD_PARAM_LEN_MAX);
1390 pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1396 /* Get rid of the final newline */
1397 if (buf[len - 1] == '\n')
1398 buf[len - 1] = '\0';
1400 for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1401 tokens[i] = strsep(&pbuf, ",");
1404 pr_err("UBI error: too many arguments at \"%s\"\n", val);
1408 p = &mtd_dev_param[mtd_devs];
1409 strcpy(&p->name[0], tokens[0]);
1413 p->vid_hdr_offs = bytes_str_to_int(token);
1415 if (p->vid_hdr_offs < 0)
1416 return p->vid_hdr_offs;
1421 int err = kstrtoint(token, 10, &p->max_beb_per1024);
1424 pr_err("UBI error: bad value for max_beb_per1024 parameter: %s",
1432 int err = kstrtoint(token, 10, &p->ubi_num);
1435 pr_err("UBI error: bad value for ubi_num parameter: %s",
1440 p->ubi_num = UBI_DEV_NUM_AUTO;
1446 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 0400);
1447 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1448 "Multiple \"mtd\" parameters may be specified.\n"
1449 "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1450 "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1451 "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1452 __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1453 "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1455 "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1456 "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"
1457 "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"
1458 "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"
1459 "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1460 #ifdef CONFIG_MTD_UBI_FASTMAP
1461 module_param(fm_autoconvert, bool, 0644);
1462 MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1463 module_param(fm_debug, bool, 0);
1464 MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1466 MODULE_VERSION(__stringify(UBI_VERSION));
1467 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1468 MODULE_AUTHOR("Artem Bityutskiy");
1469 MODULE_LICENSE("GPL");