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-rw-r--r--drivers/mtd/ubi/eba.c1241
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diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
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1/*
2 * Copyright (c) International Business Machines Corp., 2006
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12 * the GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Author: Artem Bityutskiy (Битюцкий Артём)
19 */
20
21/*
22 * The UBI Eraseblock Association (EBA) unit.
23 *
24 * This unit is responsible for I/O to/from logical eraseblock.
25 *
26 * Although in this implementation the EBA table is fully kept and managed in
27 * RAM, which assumes poor scalability, it might be (partially) maintained on
28 * flash in future implementations.
29 *
30 * The EBA unit implements per-logical eraseblock locking. Before accessing a
31 * logical eraseblock it is locked for reading or writing. The per-logical
32 * eraseblock locking is implemented by means of the lock tree. The lock tree
33 * is an RB-tree which refers all the currently locked logical eraseblocks. The
34 * lock tree elements are &struct ltree_entry objects. They are indexed by
35 * (@vol_id, @lnum) pairs.
36 *
37 * EBA also maintains the global sequence counter which is incremented each
38 * time a logical eraseblock is mapped to a physical eraseblock and it is
39 * stored in the volume identifier header. This means that each VID header has
40 * a unique sequence number. The sequence number is only increased an we assume
41 * 64 bits is enough to never overflow.
42 */
43
44#include <linux/slab.h>
45#include <linux/crc32.h>
46#include <linux/err.h>
47#include "ubi.h"
48
49/**
50 * struct ltree_entry - an entry in the lock tree.
51 * @rb: links RB-tree nodes
52 * @vol_id: volume ID of the locked logical eraseblock
53 * @lnum: locked logical eraseblock number
54 * @users: how many tasks are using this logical eraseblock or wait for it
55 * @mutex: read/write mutex to implement read/write access serialization to
56 * the (@vol_id, @lnum) logical eraseblock
57 *
58 * When a logical eraseblock is being locked - corresponding &struct ltree_entry
59 * object is inserted to the lock tree (@ubi->ltree).
60 */
61struct ltree_entry {
62 struct rb_node rb;
63 int vol_id;
64 int lnum;
65 int users;
66 struct rw_semaphore mutex;
67};
68
69/* Slab cache for lock-tree entries */
70static struct kmem_cache *ltree_slab;
71
72/**
73 * next_sqnum - get next sequence number.
74 * @ubi: UBI device description object
75 *
76 * This function returns next sequence number to use, which is just the current
77 * global sequence counter value. It also increases the global sequence
78 * counter.
79 */
80static unsigned long long next_sqnum(struct ubi_device *ubi)
81{
82 unsigned long long sqnum;
83
84 spin_lock(&ubi->ltree_lock);
85 sqnum = ubi->global_sqnum++;
86 spin_unlock(&ubi->ltree_lock);
87
88 return sqnum;
89}
90
91/**
92 * ubi_get_compat - get compatibility flags of a volume.
93 * @ubi: UBI device description object
94 * @vol_id: volume ID
95 *
96 * This function returns compatibility flags for an internal volume. User
97 * volumes have no compatibility flags, so %0 is returned.
98 */
99static int ubi_get_compat(const struct ubi_device *ubi, int vol_id)
100{
101 if (vol_id == UBI_LAYOUT_VOL_ID)
102 return UBI_LAYOUT_VOLUME_COMPAT;
103 return 0;
104}
105
106/**
107 * ltree_lookup - look up the lock tree.
108 * @ubi: UBI device description object
109 * @vol_id: volume ID
110 * @lnum: logical eraseblock number
111 *
112 * This function returns a pointer to the corresponding &struct ltree_entry
113 * object if the logical eraseblock is locked and %NULL if it is not.
114 * @ubi->ltree_lock has to be locked.
115 */
116static struct ltree_entry *ltree_lookup(struct ubi_device *ubi, int vol_id,
117 int lnum)
118{
119 struct rb_node *p;
120
121 p = ubi->ltree.rb_node;
122 while (p) {
123 struct ltree_entry *le;
124
125 le = rb_entry(p, struct ltree_entry, rb);
126
127 if (vol_id < le->vol_id)
128 p = p->rb_left;
129 else if (vol_id > le->vol_id)
130 p = p->rb_right;
131 else {
132 if (lnum < le->lnum)
133 p = p->rb_left;
134 else if (lnum > le->lnum)
135 p = p->rb_right;
136 else
137 return le;
138 }
139 }
140
141 return NULL;
142}
143
144/**
145 * ltree_add_entry - add new entry to the lock tree.
146 * @ubi: UBI device description object
147 * @vol_id: volume ID
148 * @lnum: logical eraseblock number
149 *
150 * This function adds new entry for logical eraseblock (@vol_id, @lnum) to the
151 * lock tree. If such entry is already there, its usage counter is increased.
152 * Returns pointer to the lock tree entry or %-ENOMEM if memory allocation
153 * failed.
154 */
155static struct ltree_entry *ltree_add_entry(struct ubi_device *ubi, int vol_id,
156 int lnum)
157{
158 struct ltree_entry *le, *le1, *le_free;
159
160 le = kmem_cache_alloc(ltree_slab, GFP_KERNEL);
161 if (!le)
162 return ERR_PTR(-ENOMEM);
163
164 le->vol_id = vol_id;
165 le->lnum = lnum;
166
167 spin_lock(&ubi->ltree_lock);
168 le1 = ltree_lookup(ubi, vol_id, lnum);
169
170 if (le1) {
171 /*
172 * This logical eraseblock is already locked. The newly
173 * allocated lock entry is not needed.
174 */
175 le_free = le;
176 le = le1;
177 } else {
178 struct rb_node **p, *parent = NULL;
179
180 /*
181 * No lock entry, add the newly allocated one to the
182 * @ubi->ltree RB-tree.
183 */
184 le_free = NULL;
185
186 p = &ubi->ltree.rb_node;
187 while (*p) {
188 parent = *p;
189 le1 = rb_entry(parent, struct ltree_entry, rb);
190
191 if (vol_id < le1->vol_id)
192 p = &(*p)->rb_left;
193 else if (vol_id > le1->vol_id)
194 p = &(*p)->rb_right;
195 else {
196 ubi_assert(lnum != le1->lnum);
197 if (lnum < le1->lnum)
198 p = &(*p)->rb_left;
199 else
200 p = &(*p)->rb_right;
201 }
202 }
203
204 rb_link_node(&le->rb, parent, p);
205 rb_insert_color(&le->rb, &ubi->ltree);
206 }
207 le->users += 1;
208 spin_unlock(&ubi->ltree_lock);
209
210 if (le_free)
211 kmem_cache_free(ltree_slab, le_free);
212
213 return le;
214}
215
216/**
217 * leb_read_lock - lock logical eraseblock for reading.
218 * @ubi: UBI device description object
219 * @vol_id: volume ID
220 * @lnum: logical eraseblock number
221 *
222 * This function locks a logical eraseblock for reading. Returns zero in case
223 * of success and a negative error code in case of failure.
224 */
225static int leb_read_lock(struct ubi_device *ubi, int vol_id, int lnum)
226{
227 struct ltree_entry *le;
228
229 le = ltree_add_entry(ubi, vol_id, lnum);
230 if (IS_ERR(le))
231 return PTR_ERR(le);
232 down_read(&le->mutex);
233 return 0;
234}
235
236/**
237 * leb_read_unlock - unlock logical eraseblock.
238 * @ubi: UBI device description object
239 * @vol_id: volume ID
240 * @lnum: logical eraseblock number
241 */
242static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum)
243{
244 int free = 0;
245 struct ltree_entry *le;
246
247 spin_lock(&ubi->ltree_lock);
248 le = ltree_lookup(ubi, vol_id, lnum);
249 le->users -= 1;
250 ubi_assert(le->users >= 0);
251 if (le->users == 0) {
252 rb_erase(&le->rb, &ubi->ltree);
253 free = 1;
254 }
255 spin_unlock(&ubi->ltree_lock);
256
257 up_read(&le->mutex);
258 if (free)
259 kmem_cache_free(ltree_slab, le);
260}
261
262/**
263 * leb_write_lock - lock logical eraseblock for writing.
264 * @ubi: UBI device description object
265 * @vol_id: volume ID
266 * @lnum: logical eraseblock number
267 *
268 * This function locks a logical eraseblock for writing. Returns zero in case
269 * of success and a negative error code in case of failure.
270 */
271static int leb_write_lock(struct ubi_device *ubi, int vol_id, int lnum)
272{
273 struct ltree_entry *le;
274
275 le = ltree_add_entry(ubi, vol_id, lnum);
276 if (IS_ERR(le))
277 return PTR_ERR(le);
278 down_write(&le->mutex);
279 return 0;
280}
281
282/**
283 * leb_write_unlock - unlock logical eraseblock.
284 * @ubi: UBI device description object
285 * @vol_id: volume ID
286 * @lnum: logical eraseblock number
287 */
288static void leb_write_unlock(struct ubi_device *ubi, int vol_id, int lnum)
289{
290 int free;
291 struct ltree_entry *le;
292
293 spin_lock(&ubi->ltree_lock);
294 le = ltree_lookup(ubi, vol_id, lnum);
295 le->users -= 1;
296 ubi_assert(le->users >= 0);
297 if (le->users == 0) {
298 rb_erase(&le->rb, &ubi->ltree);
299 free = 1;
300 } else
301 free = 0;
302 spin_unlock(&ubi->ltree_lock);
303
304 up_write(&le->mutex);
305 if (free)
306 kmem_cache_free(ltree_slab, le);
307}
308
309/**
310 * ubi_eba_unmap_leb - un-map logical eraseblock.
311 * @ubi: UBI device description object
312 * @vol_id: volume ID
313 * @lnum: logical eraseblock number
314 *
315 * This function un-maps logical eraseblock @lnum and schedules corresponding
316 * physical eraseblock for erasure. Returns zero in case of success and a
317 * negative error code in case of failure.
318 */
319int ubi_eba_unmap_leb(struct ubi_device *ubi, int vol_id, int lnum)
320{
321 int idx = vol_id2idx(ubi, vol_id), err, pnum;
322 struct ubi_volume *vol = ubi->volumes[idx];
323
324 if (ubi->ro_mode)
325 return -EROFS;
326
327 err = leb_write_lock(ubi, vol_id, lnum);
328 if (err)
329 return err;
330
331 pnum = vol->eba_tbl[lnum];
332 if (pnum < 0)
333 /* This logical eraseblock is already unmapped */
334 goto out_unlock;
335
336 dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum);
337
338 vol->eba_tbl[lnum] = UBI_LEB_UNMAPPED;
339 err = ubi_wl_put_peb(ubi, pnum, 0);
340
341out_unlock:
342 leb_write_unlock(ubi, vol_id, lnum);
343 return err;
344}
345
346/**
347 * ubi_eba_read_leb - read data.
348 * @ubi: UBI device description object
349 * @vol_id: volume ID
350 * @lnum: logical eraseblock number
351 * @buf: buffer to store the read data
352 * @offset: offset from where to read
353 * @len: how many bytes to read
354 * @check: data CRC check flag
355 *
356 * If the logical eraseblock @lnum is unmapped, @buf is filled with 0xFF
357 * bytes. The @check flag only makes sense for static volumes and forces
358 * eraseblock data CRC checking.
359 *
360 * In case of success this function returns zero. In case of a static volume,
361 * if data CRC mismatches - %-EBADMSG is returned. %-EBADMSG may also be
362 * returned for any volume type if an ECC error was detected by the MTD device
363 * driver. Other negative error cored may be returned in case of other errors.
364 */
365int ubi_eba_read_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf,
366 int offset, int len, int check)
367{
368 int err, pnum, scrub = 0, idx = vol_id2idx(ubi, vol_id);
369 struct ubi_vid_hdr *vid_hdr;
370 struct ubi_volume *vol = ubi->volumes[idx];
371 uint32_t crc, crc1;
372
373 err = leb_read_lock(ubi, vol_id, lnum);
374 if (err)
375 return err;
376
377 pnum = vol->eba_tbl[lnum];
378 if (pnum < 0) {
379 /*
380 * The logical eraseblock is not mapped, fill the whole buffer
381 * with 0xFF bytes. The exception is static volumes for which
382 * it is an error to read unmapped logical eraseblocks.
383 */
384 dbg_eba("read %d bytes from offset %d of LEB %d:%d (unmapped)",
385 len, offset, vol_id, lnum);
386 leb_read_unlock(ubi, vol_id, lnum);
387 ubi_assert(vol->vol_type != UBI_STATIC_VOLUME);
388 memset(buf, 0xFF, len);
389 return 0;
390 }
391
392 dbg_eba("read %d bytes from offset %d of LEB %d:%d, PEB %d",
393 len, offset, vol_id, lnum, pnum);
394
395 if (vol->vol_type == UBI_DYNAMIC_VOLUME)
396 check = 0;
397
398retry:
399 if (check) {
400 vid_hdr = ubi_zalloc_vid_hdr(ubi);
401 if (!vid_hdr) {
402 err = -ENOMEM;
403 goto out_unlock;
404 }
405
406 err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
407 if (err && err != UBI_IO_BITFLIPS) {
408 if (err > 0) {
409 /*
410 * The header is either absent or corrupted.
411 * The former case means there is a bug -
412 * switch to read-only mode just in case.
413 * The latter case means a real corruption - we
414 * may try to recover data. FIXME: but this is
415 * not implemented.
416 */
417 if (err == UBI_IO_BAD_VID_HDR) {
418 ubi_warn("bad VID header at PEB %d, LEB"
419 "%d:%d", pnum, vol_id, lnum);
420 err = -EBADMSG;
421 } else
422 ubi_ro_mode(ubi);
423 }
424 goto out_free;
425 } else if (err == UBI_IO_BITFLIPS)
426 scrub = 1;
427
428 ubi_assert(lnum < ubi32_to_cpu(vid_hdr->used_ebs));
429 ubi_assert(len == ubi32_to_cpu(vid_hdr->data_size));
430
431 crc = ubi32_to_cpu(vid_hdr->data_crc);
432 ubi_free_vid_hdr(ubi, vid_hdr);
433 }
434
435 err = ubi_io_read_data(ubi, buf, pnum, offset, len);
436 if (err) {
437 if (err == UBI_IO_BITFLIPS) {
438 scrub = 1;
439 err = 0;
440 } else if (err == -EBADMSG) {
441 if (vol->vol_type == UBI_DYNAMIC_VOLUME)
442 goto out_unlock;
443 scrub = 1;
444 if (!check) {
445 ubi_msg("force data checking");
446 check = 1;
447 goto retry;
448 }
449 } else
450 goto out_unlock;
451 }
452
453 if (check) {
454 crc1 = crc32(UBI_CRC32_INIT, buf, len);
455 if (crc1 != crc) {
456 ubi_warn("CRC error: calculated %#08x, must be %#08x",
457 crc1, crc);
458 err = -EBADMSG;
459 goto out_unlock;
460 }
461 }
462
463 if (scrub)
464 err = ubi_wl_scrub_peb(ubi, pnum);
465
466 leb_read_unlock(ubi, vol_id, lnum);
467 return err;
468
469out_free:
470 ubi_free_vid_hdr(ubi, vid_hdr);
471out_unlock:
472 leb_read_unlock(ubi, vol_id, lnum);
473 return err;
474}
475
476/**
477 * recover_peb - recover from write failure.
478 * @ubi: UBI device description object
479 * @pnum: the physical eraseblock to recover
480 * @vol_id: volume ID
481 * @lnum: logical eraseblock number
482 * @buf: data which was not written because of the write failure
483 * @offset: offset of the failed write
484 * @len: how many bytes should have been written
485 *
486 * This function is called in case of a write failure and moves all good data
487 * from the potentially bad physical eraseblock to a good physical eraseblock.
488 * This function also writes the data which was not written due to the failure.
489 * Returns new physical eraseblock number in case of success, and a negative
490 * error code in case of failure.
491 */
492static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
493 const void *buf, int offset, int len)
494{
495 int err, idx = vol_id2idx(ubi, vol_id), new_pnum, data_size, tries = 0;
496 struct ubi_volume *vol = ubi->volumes[idx];
497 struct ubi_vid_hdr *vid_hdr;
498 unsigned char *new_buf;
499
500 vid_hdr = ubi_zalloc_vid_hdr(ubi);
501 if (!vid_hdr) {
502 return -ENOMEM;
503 }
504
505retry:
506 new_pnum = ubi_wl_get_peb(ubi, UBI_UNKNOWN);
507 if (new_pnum < 0) {
508 ubi_free_vid_hdr(ubi, vid_hdr);
509 return new_pnum;
510 }
511
512 ubi_msg("recover PEB %d, move data to PEB %d", pnum, new_pnum);
513
514 err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
515 if (err && err != UBI_IO_BITFLIPS) {
516 if (err > 0)
517 err = -EIO;
518 goto out_put;
519 }
520
521 vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi));
522 err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr);
523 if (err)
524 goto write_error;
525
526 data_size = offset + len;
527 new_buf = kmalloc(data_size, GFP_KERNEL);
528 if (!new_buf) {
529 err = -ENOMEM;
530 goto out_put;
531 }
532 memset(new_buf + offset, 0xFF, len);
533
534 /* Read everything before the area where the write failure happened */
535 if (offset > 0) {
536 err = ubi_io_read_data(ubi, new_buf, pnum, 0, offset);
537 if (err && err != UBI_IO_BITFLIPS) {
538 kfree(new_buf);
539 goto out_put;
540 }
541 }
542
543 memcpy(new_buf + offset, buf, len);
544
545 err = ubi_io_write_data(ubi, new_buf, new_pnum, 0, data_size);
546 if (err) {
547 kfree(new_buf);
548 goto write_error;
549 }
550
551 kfree(new_buf);
552 ubi_free_vid_hdr(ubi, vid_hdr);
553
554 vol->eba_tbl[lnum] = new_pnum;
555 ubi_wl_put_peb(ubi, pnum, 1);
556
557 ubi_msg("data was successfully recovered");
558 return 0;
559
560out_put:
561 ubi_wl_put_peb(ubi, new_pnum, 1);
562 ubi_free_vid_hdr(ubi, vid_hdr);
563 return err;
564
565write_error:
566 /*
567 * Bad luck? This physical eraseblock is bad too? Crud. Let's try to
568 * get another one.
569 */
570 ubi_warn("failed to write to PEB %d", new_pnum);
571 ubi_wl_put_peb(ubi, new_pnum, 1);
572 if (++tries > UBI_IO_RETRIES) {
573 ubi_free_vid_hdr(ubi, vid_hdr);
574 return err;
575 }
576 ubi_msg("try again");
577 goto retry;
578}
579
580/**
581 * ubi_eba_write_leb - write data to dynamic volume.
582 * @ubi: UBI device description object
583 * @vol_id: volume ID
584 * @lnum: logical eraseblock number
585 * @buf: the data to write
586 * @offset: offset within the logical eraseblock where to write
587 * @len: how many bytes to write
588 * @dtype: data type
589 *
590 * This function writes data to logical eraseblock @lnum of a dynamic volume
591 * @vol_id. Returns zero in case of success and a negative error code in case
592 * of failure. In case of error, it is possible that something was still
593 * written to the flash media, but may be some garbage.
594 */
595int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum,
596 const void *buf, int offset, int len, int dtype)
597{
598 int idx = vol_id2idx(ubi, vol_id), err, pnum, tries = 0;
599 struct ubi_volume *vol = ubi->volumes[idx];
600 struct ubi_vid_hdr *vid_hdr;
601
602 if (ubi->ro_mode)
603 return -EROFS;
604
605 err = leb_write_lock(ubi, vol_id, lnum);
606 if (err)
607 return err;
608
609 pnum = vol->eba_tbl[lnum];
610 if (pnum >= 0) {
611 dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d",
612 len, offset, vol_id, lnum, pnum);
613
614 err = ubi_io_write_data(ubi, buf, pnum, offset, len);
615 if (err) {
616 ubi_warn("failed to write data to PEB %d", pnum);
617 if (err == -EIO && ubi->bad_allowed)
618 err = recover_peb(ubi, pnum, vol_id, lnum, buf, offset, len);
619 if (err)
620 ubi_ro_mode(ubi);
621 }
622 leb_write_unlock(ubi, vol_id, lnum);
623 return err;
624 }
625
626 /*
627 * The logical eraseblock is not mapped. We have to get a free physical
628 * eraseblock and write the volume identifier header there first.
629 */
630 vid_hdr = ubi_zalloc_vid_hdr(ubi);
631 if (!vid_hdr) {
632 leb_write_unlock(ubi, vol_id, lnum);
633 return -ENOMEM;
634 }
635
636 vid_hdr->vol_type = UBI_VID_DYNAMIC;
637 vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi));
638 vid_hdr->vol_id = cpu_to_ubi32(vol_id);
639 vid_hdr->lnum = cpu_to_ubi32(lnum);
640 vid_hdr->compat = ubi_get_compat(ubi, vol_id);
641 vid_hdr->data_pad = cpu_to_ubi32(vol->data_pad);
642
643retry:
644 pnum = ubi_wl_get_peb(ubi, dtype);
645 if (pnum < 0) {
646 ubi_free_vid_hdr(ubi, vid_hdr);
647 leb_write_unlock(ubi, vol_id, lnum);
648 return pnum;
649 }
650
651 dbg_eba("write VID hdr and %d bytes at offset %d of LEB %d:%d, PEB %d",
652 len, offset, vol_id, lnum, pnum);
653
654 err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
655 if (err) {
656 ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
657 vol_id, lnum, pnum);
658 goto write_error;
659 }
660
661 err = ubi_io_write_data(ubi, buf, pnum, offset, len);
662 if (err) {
663 ubi_warn("failed to write %d bytes at offset %d of LEB %d:%d, "
664 "PEB %d", len, offset, vol_id, lnum, pnum);
665 goto write_error;
666 }
667
668 vol->eba_tbl[lnum] = pnum;
669
670 leb_write_unlock(ubi, vol_id, lnum);
671 ubi_free_vid_hdr(ubi, vid_hdr);
672 return 0;
673
674write_error:
675 if (err != -EIO || !ubi->bad_allowed) {
676 ubi_ro_mode(ubi);
677 leb_write_unlock(ubi, vol_id, lnum);
678 ubi_free_vid_hdr(ubi, vid_hdr);
679 return err;
680 }
681
682 /*
683 * Fortunately, this is the first write operation to this physical
684 * eraseblock, so just put it and request a new one. We assume that if
685 * this physical eraseblock went bad, the erase code will handle that.
686 */
687 err = ubi_wl_put_peb(ubi, pnum, 1);
688 if (err || ++tries > UBI_IO_RETRIES) {
689 ubi_ro_mode(ubi);
690 leb_write_unlock(ubi, vol_id, lnum);
691 ubi_free_vid_hdr(ubi, vid_hdr);
692 return err;
693 }
694
695 vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi));
696 ubi_msg("try another PEB");
697 goto retry;
698}
699
700/**
701 * ubi_eba_write_leb_st - write data to static volume.
702 * @ubi: UBI device description object
703 * @vol_id: volume ID
704 * @lnum: logical eraseblock number
705 * @buf: data to write
706 * @len: how many bytes to write
707 * @dtype: data type
708 * @used_ebs: how many logical eraseblocks will this volume contain
709 *
710 * This function writes data to logical eraseblock @lnum of static volume
711 * @vol_id. The @used_ebs argument should contain total number of logical
712 * eraseblock in this static volume.
713 *
714 * When writing to the last logical eraseblock, the @len argument doesn't have
715 * to be aligned to the minimal I/O unit size. Instead, it has to be equivalent
716 * to the real data size, although the @buf buffer has to contain the
717 * alignment. In all other cases, @len has to be aligned.
718 *
719 * It is prohibited to write more then once to logical eraseblocks of static
720 * volumes. This function returns zero in case of success and a negative error
721 * code in case of failure.
722 */
723int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum,
724 const void *buf, int len, int dtype, int used_ebs)
725{
726 int err, pnum, tries = 0, data_size = len;
727 int idx = vol_id2idx(ubi, vol_id);
728 struct ubi_volume *vol = ubi->volumes[idx];
729 struct ubi_vid_hdr *vid_hdr;
730 uint32_t crc;
731
732 if (ubi->ro_mode)
733 return -EROFS;
734
735 if (lnum == used_ebs - 1)
736 /* If this is the last LEB @len may be unaligned */
737 len = ALIGN(data_size, ubi->min_io_size);
738 else
739 ubi_assert(len % ubi->min_io_size == 0);
740
741 vid_hdr = ubi_zalloc_vid_hdr(ubi);
742 if (!vid_hdr)
743 return -ENOMEM;
744
745 err = leb_write_lock(ubi, vol_id, lnum);
746 if (err) {
747 ubi_free_vid_hdr(ubi, vid_hdr);
748 return err;
749 }
750
751 vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi));
752 vid_hdr->vol_id = cpu_to_ubi32(vol_id);
753 vid_hdr->lnum = cpu_to_ubi32(lnum);
754 vid_hdr->compat = ubi_get_compat(ubi, vol_id);
755 vid_hdr->data_pad = cpu_to_ubi32(vol->data_pad);
756
757 crc = crc32(UBI_CRC32_INIT, buf, data_size);
758 vid_hdr->vol_type = UBI_VID_STATIC;
759 vid_hdr->data_size = cpu_to_ubi32(data_size);
760 vid_hdr->used_ebs = cpu_to_ubi32(used_ebs);
761 vid_hdr->data_crc = cpu_to_ubi32(crc);
762
763retry:
764 pnum = ubi_wl_get_peb(ubi, dtype);
765 if (pnum < 0) {
766 ubi_free_vid_hdr(ubi, vid_hdr);
767 leb_write_unlock(ubi, vol_id, lnum);
768 return pnum;
769 }
770
771 dbg_eba("write VID hdr and %d bytes at LEB %d:%d, PEB %d, used_ebs %d",
772 len, vol_id, lnum, pnum, used_ebs);
773
774 err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
775 if (err) {
776 ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
777 vol_id, lnum, pnum);
778 goto write_error;
779 }
780
781 err = ubi_io_write_data(ubi, buf, pnum, 0, len);
782 if (err) {
783 ubi_warn("failed to write %d bytes of data to PEB %d",
784 len, pnum);
785 goto write_error;
786 }
787
788 ubi_assert(vol->eba_tbl[lnum] < 0);
789 vol->eba_tbl[lnum] = pnum;
790
791 leb_write_unlock(ubi, vol_id, lnum);
792 ubi_free_vid_hdr(ubi, vid_hdr);
793 return 0;
794
795write_error:
796 if (err != -EIO || !ubi->bad_allowed) {
797 /*
798 * This flash device does not admit of bad eraseblocks or
799 * something nasty and unexpected happened. Switch to read-only
800 * mode just in case.
801 */
802 ubi_ro_mode(ubi);
803 leb_write_unlock(ubi, vol_id, lnum);
804 ubi_free_vid_hdr(ubi, vid_hdr);
805 return err;
806 }
807
808 err = ubi_wl_put_peb(ubi, pnum, 1);
809 if (err || ++tries > UBI_IO_RETRIES) {
810 ubi_ro_mode(ubi);
811 leb_write_unlock(ubi, vol_id, lnum);
812 ubi_free_vid_hdr(ubi, vid_hdr);
813 return err;
814 }
815
816 vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi));
817 ubi_msg("try another PEB");
818 goto retry;
819}
820
821/*
822 * ubi_eba_atomic_leb_change - change logical eraseblock atomically.
823 * @ubi: UBI device description object
824 * @vol_id: volume ID
825 * @lnum: logical eraseblock number
826 * @buf: data to write
827 * @len: how many bytes to write
828 * @dtype: data type
829 *
830 * This function changes the contents of a logical eraseblock atomically. @buf
831 * has to contain new logical eraseblock data, and @len - the length of the
832 * data, which has to be aligned. This function guarantees that in case of an
833 * unclean reboot the old contents is preserved. Returns zero in case of
834 * success and a negative error code in case of failure.
835 */
836int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum,
837 const void *buf, int len, int dtype)
838{
839 int err, pnum, tries = 0, idx = vol_id2idx(ubi, vol_id);
840 struct ubi_volume *vol = ubi->volumes[idx];
841 struct ubi_vid_hdr *vid_hdr;
842 uint32_t crc;
843
844 if (ubi->ro_mode)
845 return -EROFS;
846
847 vid_hdr = ubi_zalloc_vid_hdr(ubi);
848 if (!vid_hdr)
849 return -ENOMEM;
850
851 err = leb_write_lock(ubi, vol_id, lnum);
852 if (err) {
853 ubi_free_vid_hdr(ubi, vid_hdr);
854 return err;
855 }
856
857 vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi));
858 vid_hdr->vol_id = cpu_to_ubi32(vol_id);
859 vid_hdr->lnum = cpu_to_ubi32(lnum);
860 vid_hdr->compat = ubi_get_compat(ubi, vol_id);
861 vid_hdr->data_pad = cpu_to_ubi32(vol->data_pad);
862
863 crc = crc32(UBI_CRC32_INIT, buf, len);
864 vid_hdr->vol_type = UBI_VID_STATIC;
865 vid_hdr->data_size = cpu_to_ubi32(len);
866 vid_hdr->copy_flag = 1;
867 vid_hdr->data_crc = cpu_to_ubi32(crc);
868
869retry:
870 pnum = ubi_wl_get_peb(ubi, dtype);
871 if (pnum < 0) {
872 ubi_free_vid_hdr(ubi, vid_hdr);
873 leb_write_unlock(ubi, vol_id, lnum);
874 return pnum;
875 }
876
877 dbg_eba("change LEB %d:%d, PEB %d, write VID hdr to PEB %d",
878 vol_id, lnum, vol->eba_tbl[lnum], pnum);
879
880 err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
881 if (err) {
882 ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
883 vol_id, lnum, pnum);
884 goto write_error;
885 }
886
887 err = ubi_io_write_data(ubi, buf, pnum, 0, len);
888 if (err) {
889 ubi_warn("failed to write %d bytes of data to PEB %d",
890 len, pnum);
891 goto write_error;
892 }
893
894 err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 1);
895 if (err) {
896 ubi_free_vid_hdr(ubi, vid_hdr);
897 leb_write_unlock(ubi, vol_id, lnum);
898 return err;
899 }
900
901 vol->eba_tbl[lnum] = pnum;
902 leb_write_unlock(ubi, vol_id, lnum);
903 ubi_free_vid_hdr(ubi, vid_hdr);
904 return 0;
905
906write_error:
907 if (err != -EIO || !ubi->bad_allowed) {
908 /*
909 * This flash device does not admit of bad eraseblocks or
910 * something nasty and unexpected happened. Switch to read-only
911 * mode just in case.
912 */
913 ubi_ro_mode(ubi);
914 leb_write_unlock(ubi, vol_id, lnum);
915 ubi_free_vid_hdr(ubi, vid_hdr);
916 return err;
917 }
918
919 err = ubi_wl_put_peb(ubi, pnum, 1);
920 if (err || ++tries > UBI_IO_RETRIES) {
921 ubi_ro_mode(ubi);
922 leb_write_unlock(ubi, vol_id, lnum);
923 ubi_free_vid_hdr(ubi, vid_hdr);
924 return err;
925 }
926
927 vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi));
928 ubi_msg("try another PEB");
929 goto retry;
930}
931
932/**
933 * ltree_entry_ctor - lock tree entries slab cache constructor.
934 * @obj: the lock-tree entry to construct
935 * @cache: the lock tree entry slab cache
936 * @flags: constructor flags
937 */
938static void ltree_entry_ctor(void *obj, struct kmem_cache *cache,
939 unsigned long flags)
940{
941 struct ltree_entry *le = obj;
942
943 if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) !=
944 SLAB_CTOR_CONSTRUCTOR)
945 return;
946
947 le->users = 0;
948 init_rwsem(&le->mutex);
949}
950
951/**
952 * ubi_eba_copy_leb - copy logical eraseblock.
953 * @ubi: UBI device description object
954 * @from: physical eraseblock number from where to copy
955 * @to: physical eraseblock number where to copy
956 * @vid_hdr: VID header of the @from physical eraseblock
957 *
958 * This function copies logical eraseblock from physical eraseblock @from to
959 * physical eraseblock @to. The @vid_hdr buffer may be changed by this
960 * function. Returns zero in case of success, %UBI_IO_BITFLIPS if the operation
961 * was canceled because bit-flips were detected at the target PEB, and a
962 * negative error code in case of failure.
963 */
964int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
965 struct ubi_vid_hdr *vid_hdr)
966{
967 int err, vol_id, lnum, data_size, aldata_size, pnum, idx;
968 struct ubi_volume *vol;
969 uint32_t crc;
970 void *buf, *buf1 = NULL;
971
972 vol_id = ubi32_to_cpu(vid_hdr->vol_id);
973 lnum = ubi32_to_cpu(vid_hdr->lnum);
974
975 dbg_eba("copy LEB %d:%d, PEB %d to PEB %d", vol_id, lnum, from, to);
976
977 if (vid_hdr->vol_type == UBI_VID_STATIC) {
978 data_size = ubi32_to_cpu(vid_hdr->data_size);
979 aldata_size = ALIGN(data_size, ubi->min_io_size);
980 } else
981 data_size = aldata_size =
982 ubi->leb_size - ubi32_to_cpu(vid_hdr->data_pad);
983
984 buf = kmalloc(aldata_size, GFP_KERNEL);
985 if (!buf)
986 return -ENOMEM;
987
988 /*
989 * We do not want anybody to write to this logical eraseblock while we
990 * are moving it, so we lock it.
991 */
992 err = leb_write_lock(ubi, vol_id, lnum);
993 if (err) {
994 kfree(buf);
995 return err;
996 }
997
998 /*
999 * But the logical eraseblock might have been put by this time.
1000 * Cancel if it is true.
1001 */
1002 idx = vol_id2idx(ubi, vol_id);
1003
1004 /*
1005 * We may race with volume deletion/re-size, so we have to hold
1006 * @ubi->volumes_lock.
1007 */
1008 spin_lock(&ubi->volumes_lock);
1009 vol = ubi->volumes[idx];
1010 if (!vol) {
1011 dbg_eba("volume %d was removed meanwhile", vol_id);
1012 spin_unlock(&ubi->volumes_lock);
1013 goto out_unlock;
1014 }
1015
1016 pnum = vol->eba_tbl[lnum];
1017 if (pnum != from) {
1018 dbg_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to "
1019 "PEB %d, cancel", vol_id, lnum, from, pnum);
1020 spin_unlock(&ubi->volumes_lock);
1021 goto out_unlock;
1022 }
1023 spin_unlock(&ubi->volumes_lock);
1024
1025 /* OK, now the LEB is locked and we can safely start moving it */
1026
1027 dbg_eba("read %d bytes of data", aldata_size);
1028 err = ubi_io_read_data(ubi, buf, from, 0, aldata_size);
1029 if (err && err != UBI_IO_BITFLIPS) {
1030 ubi_warn("error %d while reading data from PEB %d",
1031 err, from);
1032 goto out_unlock;
1033 }
1034
1035 /*
1036 * Now we have got to calculate how much data we have to to copy. In
1037 * case of a static volume it is fairly easy - the VID header contains
1038 * the data size. In case of a dynamic volume it is more difficult - we
1039 * have to read the contents, cut 0xFF bytes from the end and copy only
1040 * the first part. We must do this to avoid writing 0xFF bytes as it
1041 * may have some side-effects. And not only this. It is important not
1042 * to include those 0xFFs to CRC because later the they may be filled
1043 * by data.
1044 */
1045 if (vid_hdr->vol_type == UBI_VID_DYNAMIC)
1046 aldata_size = data_size =
1047 ubi_calc_data_len(ubi, buf, data_size);
1048
1049 cond_resched();
1050 crc = crc32(UBI_CRC32_INIT, buf, data_size);
1051 cond_resched();
1052
1053 /*
1054 * It may turn out to me that the whole @from physical eraseblock
1055 * contains only 0xFF bytes. Then we have to only write the VID header
1056 * and do not write any data. This also means we should not set
1057 * @vid_hdr->copy_flag, @vid_hdr->data_size, and @vid_hdr->data_crc.
1058 */
1059 if (data_size > 0) {
1060 vid_hdr->copy_flag = 1;
1061 vid_hdr->data_size = cpu_to_ubi32(data_size);
1062 vid_hdr->data_crc = cpu_to_ubi32(crc);
1063 }
1064 vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi));
1065
1066 err = ubi_io_write_vid_hdr(ubi, to, vid_hdr);
1067 if (err)
1068 goto out_unlock;
1069
1070 cond_resched();
1071
1072 /* Read the VID header back and check if it was written correctly */
1073 err = ubi_io_read_vid_hdr(ubi, to, vid_hdr, 1);
1074 if (err) {
1075 if (err != UBI_IO_BITFLIPS)
1076 ubi_warn("cannot read VID header back from PEB %d", to);
1077 goto out_unlock;
1078 }
1079
1080 if (data_size > 0) {
1081 err = ubi_io_write_data(ubi, buf, to, 0, aldata_size);
1082 if (err)
1083 goto out_unlock;
1084
1085 /*
1086 * We've written the data and are going to read it back to make
1087 * sure it was written correctly.
1088 */
1089 buf1 = kmalloc(aldata_size, GFP_KERNEL);
1090 if (!buf1) {
1091 err = -ENOMEM;
1092 goto out_unlock;
1093 }
1094
1095 cond_resched();
1096
1097 err = ubi_io_read_data(ubi, buf1, to, 0, aldata_size);
1098 if (err) {
1099 if (err != UBI_IO_BITFLIPS)
1100 ubi_warn("cannot read data back from PEB %d",
1101 to);
1102 goto out_unlock;
1103 }
1104
1105 cond_resched();
1106
1107 if (memcmp(buf, buf1, aldata_size)) {
1108 ubi_warn("read data back from PEB %d - it is different",
1109 to);
1110 goto out_unlock;
1111 }
1112 }
1113
1114 ubi_assert(vol->eba_tbl[lnum] == from);
1115 vol->eba_tbl[lnum] = to;
1116
1117 leb_write_unlock(ubi, vol_id, lnum);
1118 kfree(buf);
1119 kfree(buf1);
1120
1121 return 0;
1122
1123out_unlock:
1124 leb_write_unlock(ubi, vol_id, lnum);
1125 kfree(buf);
1126 kfree(buf1);
1127 return err;
1128}
1129
1130/**
1131 * ubi_eba_init_scan - initialize the EBA unit using scanning information.
1132 * @ubi: UBI device description object
1133 * @si: scanning information
1134 *
1135 * This function returns zero in case of success and a negative error code in
1136 * case of failure.
1137 */
1138int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
1139{
1140 int i, j, err, num_volumes;
1141 struct ubi_scan_volume *sv;
1142 struct ubi_volume *vol;
1143 struct ubi_scan_leb *seb;
1144 struct rb_node *rb;
1145
1146 dbg_eba("initialize EBA unit");
1147
1148 spin_lock_init(&ubi->ltree_lock);
1149 ubi->ltree = RB_ROOT;
1150
1151 if (ubi_devices_cnt == 0) {
1152 ltree_slab = kmem_cache_create("ubi_ltree_slab",
1153 sizeof(struct ltree_entry), 0,
1154 0, &ltree_entry_ctor, NULL);
1155 if (!ltree_slab)
1156 return -ENOMEM;
1157 }
1158
1159 ubi->global_sqnum = si->max_sqnum + 1;
1160 num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
1161
1162 for (i = 0; i < num_volumes; i++) {
1163 vol = ubi->volumes[i];
1164 if (!vol)
1165 continue;
1166
1167 cond_resched();
1168
1169 vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int),
1170 GFP_KERNEL);
1171 if (!vol->eba_tbl) {
1172 err = -ENOMEM;
1173 goto out_free;
1174 }
1175
1176 for (j = 0; j < vol->reserved_pebs; j++)
1177 vol->eba_tbl[j] = UBI_LEB_UNMAPPED;
1178
1179 sv = ubi_scan_find_sv(si, idx2vol_id(ubi, i));
1180 if (!sv)
1181 continue;
1182
1183 ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) {
1184 if (seb->lnum >= vol->reserved_pebs)
1185 /*
1186 * This may happen in case of an unclean reboot
1187 * during re-size.
1188 */
1189 ubi_scan_move_to_list(sv, seb, &si->erase);
1190 vol->eba_tbl[seb->lnum] = seb->pnum;
1191 }
1192 }
1193
1194 if (ubi->bad_allowed) {
1195 ubi_calculate_reserved(ubi);
1196
1197 if (ubi->avail_pebs < ubi->beb_rsvd_level) {
1198 /* No enough free physical eraseblocks */
1199 ubi->beb_rsvd_pebs = ubi->avail_pebs;
1200 ubi_warn("cannot reserve enough PEBs for bad PEB "
1201 "handling, reserved %d, need %d",
1202 ubi->beb_rsvd_pebs, ubi->beb_rsvd_level);
1203 } else
1204 ubi->beb_rsvd_pebs = ubi->beb_rsvd_level;
1205
1206 ubi->avail_pebs -= ubi->beb_rsvd_pebs;
1207 ubi->rsvd_pebs += ubi->beb_rsvd_pebs;
1208 }
1209
1210 dbg_eba("EBA unit is initialized");
1211 return 0;
1212
1213out_free:
1214 for (i = 0; i < num_volumes; i++) {
1215 if (!ubi->volumes[i])
1216 continue;
1217 kfree(ubi->volumes[i]->eba_tbl);
1218 }
1219 if (ubi_devices_cnt == 0)
1220 kmem_cache_destroy(ltree_slab);
1221 return err;
1222}
1223
1224/**
1225 * ubi_eba_close - close EBA unit.
1226 * @ubi: UBI device description object
1227 */
1228void ubi_eba_close(const struct ubi_device *ubi)
1229{
1230 int i, num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
1231
1232 dbg_eba("close EBA unit");
1233
1234 for (i = 0; i < num_volumes; i++) {
1235 if (!ubi->volumes[i])
1236 continue;
1237 kfree(ubi->volumes[i]->eba_tbl);
1238 }
1239 if (ubi_devices_cnt == 1)
1240 kmem_cache_destroy(ltree_slab);
1241}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-25 18:36:41 -0500