aboutsummaryrefslogtreecommitdiff
path: root/drivers/mtd/ubi/ubi.h
blob: 0ba8b0a288381f80bf0aedfed61e9b3933baa604 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
/*
 * Copyright (c) International Business Machines Corp., 2006
 * Copyright (c) Nokia Corporation, 2006, 2007
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
 * the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Author: Artem Bityutskiy (Битюцкий Артём)
 */

#ifndef __UBI_UBI_H__
#define __UBI_UBI_H__

#include <linux/init.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/spinlock.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
#include <linux/notifier.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/ubi.h>
#include <asm/pgtable.h>

#include "ubi-media.h"

/* Maximum number of supported UBI devices */
#define UBI_MAX_DEVICES 32

/* UBI name used for character devices, sysfs, etc */
#define UBI_NAME_STR "ubi"

/* Normal UBI messages */
#define ubi_msg(fmt, ...) pr_notice("UBI: " fmt "\n", ##__VA_ARGS__)
/* UBI warning messages */
#define ubi_warn(fmt, ...) pr_warn("UBI warning: %s: " fmt "\n",  \
				   __func__, ##__VA_ARGS__)
/* UBI error messages */
#define ubi_err(fmt, ...) pr_err("UBI error: %s: " fmt "\n",      \
				 __func__, ##__VA_ARGS__)

/* Background thread name pattern */
#define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"

/*
 * This marker in the EBA table means that the LEB is um-mapped.
 * NOTE! It has to have the same value as %UBI_ALL.
 */
#define UBI_LEB_UNMAPPED -1

/*
 * In case of errors, UBI tries to repeat the operation several times before
 * returning error. The below constant defines how many times UBI re-tries.
 */
#define UBI_IO_RETRIES 3

/*
 * Length of the protection queue. The length is effectively equivalent to the
 * number of (global) erase cycles PEBs are protected from the wear-leveling
 * worker.
 */
#define UBI_PROT_QUEUE_LEN 10

/* The volume ID/LEB number/erase counter is unknown */
#define UBI_UNKNOWN -1

/*
 * The UBI debugfs directory name pattern and maximum name length (3 for "ubi"
 * + 2 for the number plus 1 for the trailing zero byte.
 */
#define UBI_DFS_DIR_NAME "ubi%d"
#define UBI_DFS_DIR_LEN  (3 + 2 + 1)

/*
 * Error codes returned by the I/O sub-system.
 *
 * UBI_IO_FF: the read region of flash contains only 0xFFs
 * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
 *                     integrity error reported by the MTD driver
 *                     (uncorrectable ECC error in case of NAND)
 * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
 * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
 *                         data integrity error reported by the MTD driver
 *                         (uncorrectable ECC error in case of NAND)
 * UBI_IO_BITFLIPS: bit-flips were detected and corrected
 *
 * Note, it is probably better to have bit-flip and ebadmsg as flags which can
 * be or'ed with other error code. But this is a big change because there are
 * may callers, so it does not worth the risk of introducing a bug
 */
enum {
	UBI_IO_FF = 1,
	UBI_IO_FF_BITFLIPS,
	UBI_IO_BAD_HDR,
	UBI_IO_BAD_HDR_EBADMSG,
	UBI_IO_BITFLIPS,
};

/*
 * Return codes of the 'ubi_eba_copy_leb()' function.
 *
 * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
 *                   PEB was put meanwhile, or there is I/O on the source PEB
 * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
 *                     PEB
 * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
 *                     PEB
 * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
 *                     PEB
 * MOVE_TARGET_BITFLIPS: canceled because a bit-flip was detected in the
 *                       target PEB
 * MOVE_RETRY: retry scrubbing the PEB
 */
enum {
	MOVE_CANCEL_RACE = 1,
	MOVE_SOURCE_RD_ERR,
	MOVE_TARGET_RD_ERR,
	MOVE_TARGET_WR_ERR,
	MOVE_TARGET_BITFLIPS,
	MOVE_RETRY,
};

/*
 * Return codes of the fastmap sub-system
 *
 * UBI_NO_FASTMAP: No fastmap super block was found
 * UBI_BAD_FASTMAP: A fastmap was found but it's unusable
 */
enum {
	UBI_NO_FASTMAP = 1,
	UBI_BAD_FASTMAP,
};

/**
 * struct ubi_wl_entry - wear-leveling entry.
 * @u.rb: link in the corresponding (free/used) RB-tree
 * @u.list: link in the protection queue
 * @ec: erase counter
 * @pnum: physical eraseblock number
 *
 * This data structure is used in the WL sub-system. Each physical eraseblock
 * has a corresponding &struct wl_entry object which may be kept in different
 * RB-trees. See WL sub-system for details.
 */
struct ubi_wl_entry {
	union {
		struct rb_node rb;
		struct list_head list;
	} u;
	int ec;
	int pnum;
};

/**
 * struct ubi_ltree_entry - an entry in the lock tree.
 * @rb: links RB-tree nodes
 * @vol_id: volume ID of the locked logical eraseblock
 * @lnum: locked logical eraseblock number
 * @users: how many tasks are using this logical eraseblock or wait for it
 * @mutex: read/write mutex to implement read/write access serialization to
 *         the (@vol_id, @lnum) logical eraseblock
 *
 * This data structure is used in the EBA sub-system to implement per-LEB
 * locking. When a logical eraseblock is being locked - corresponding
 * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
 * See EBA sub-system for details.
 */
struct ubi_ltree_entry {
	struct rb_node rb;
	int vol_id;
	int lnum;
	int users;
	struct rw_semaphore mutex;
};

/**
 * struct ubi_rename_entry - volume re-name description data structure.
 * @new_name_len: new volume name length
 * @new_name: new volume name
 * @remove: if not zero, this volume should be removed, not re-named
 * @desc: descriptor of the volume
 * @list: links re-name entries into a list
 *
 * This data structure is utilized in the multiple volume re-name code. Namely,
 * UBI first creates a list of &struct ubi_rename_entry objects from the
 * &struct ubi_rnvol_req request object, and then utilizes this list to do all
 * the job.
 */
struct ubi_rename_entry {
	int new_name_len;
	char new_name[UBI_VOL_NAME_MAX + 1];
	int remove;
	struct ubi_volume_desc *desc;
	struct list_head list;
};

struct ubi_volume_desc;

/**
 * struct ubi_fastmap_layout - in-memory fastmap data structure.
 * @e: PEBs used by the current fastmap
 * @to_be_tortured: if non-zero tortured this PEB
 * @used_blocks: number of used PEBs
 * @max_pool_size: maximal size of the user pool
 * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
 */
struct ubi_fastmap_layout {
	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
	int to_be_tortured[UBI_FM_MAX_BLOCKS];
	int used_blocks;
	int max_pool_size;
	int max_wl_pool_size;
};

/**
 * struct ubi_fm_pool - in-memory fastmap pool
 * @pebs: PEBs in this pool
 * @used: number of used PEBs
 * @size: total number of PEBs in this pool
 * @max_size: maximal size of the pool
 *
 * A pool gets filled with up to max_size.
 * If all PEBs within the pool are used a new fastmap will be written
 * to the flash and the pool gets refilled with empty PEBs.
 *
 */
struct ubi_fm_pool {
	int pebs[UBI_FM_MAX_POOL_SIZE];
	int used;
	int size;
	int max_size;
};

/**
 * struct ubi_volume - UBI volume description data structure.
 * @dev: device object to make use of the the Linux device model
 * @cdev: character device object to create character device
 * @ubi: reference to the UBI device description object
 * @vol_id: volume ID
 * @ref_count: volume reference count
 * @readers: number of users holding this volume in read-only mode
 * @writers: number of users holding this volume in read-write mode
 * @exclusive: whether somebody holds this volume in exclusive mode
 *
 * @reserved_pebs: how many physical eraseblocks are reserved for this volume
 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
 * @usable_leb_size: logical eraseblock size without padding
 * @used_ebs: how many logical eraseblocks in this volume contain data
 * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
 * @used_bytes: how many bytes of data this volume contains
 * @alignment: volume alignment
 * @data_pad: how many bytes are not used at the end of physical eraseblocks to
 *            satisfy the requested alignment
 * @name_len: volume name length
 * @name: volume name
 *
 * @upd_ebs: how many eraseblocks are expected to be updated
 * @ch_lnum: LEB number which is being changing by the atomic LEB change
 *           operation
 * @upd_bytes: how many bytes are expected to be received for volume update or
 *             atomic LEB change
 * @upd_received: how many bytes were already received for volume update or
 *                atomic LEB change
 * @upd_buf: update buffer which is used to collect update data or data for
 *           atomic LEB change
 *
 * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
 * @checked: %1 if this static volume was checked
 * @corrupted: %1 if the volume is corrupted (static volumes only)
 * @upd_marker: %1 if the update marker is set for this volume
 * @updating: %1 if the volume is being updated
 * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
 * @direct_writes: %1 if direct writes are enabled for this volume
 *
 * The @corrupted field indicates that the volume's contents is corrupted.
 * Since UBI protects only static volumes, this field is not relevant to
 * dynamic volumes - it is user's responsibility to assure their data
 * integrity.
 *
 * The @upd_marker flag indicates that this volume is either being updated at
 * the moment or is damaged because of an unclean reboot.
 */
struct ubi_volume {
	struct device dev;
	struct cdev cdev;
	struct ubi_device *ubi;
	int vol_id;
	int ref_count;
	int readers;
	int writers;
	int exclusive;

	int reserved_pebs;
	int vol_type;
	int usable_leb_size;
	int used_ebs;
	int last_eb_bytes;
	long long used_bytes;
	int alignment;
	int data_pad;
	int name_len;
	char name[UBI_VOL_NAME_MAX + 1];

	int upd_ebs;
	int ch_lnum;
	long long upd_bytes;
	long long upd_received;
	void *upd_buf;

	int *eba_tbl;
	unsigned int checked:1;
	unsigned int corrupted:1;
	unsigned int upd_marker:1;
	unsigned int updating:1;
	unsigned int changing_leb:1;
	unsigned int direct_writes:1;
};

/**
 * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
 * @vol: reference to the corresponding volume description object
 * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
 */
struct ubi_volume_desc {
	struct ubi_volume *vol;
	int mode;
};

struct ubi_wl_entry;

/**
 * struct ubi_debug_info - debugging information for an UBI device.
 *
 * @chk_gen: if UBI general extra checks are enabled
 * @chk_io: if UBI I/O extra checks are enabled
 * @disable_bgt: disable the background task for testing purposes
 * @emulate_bitflips: emulate bit-flips for testing purposes
 * @emulate_io_failures: emulate write/erase failures for testing purposes
 * @dfs_dir_name: name of debugfs directory containing files of this UBI device
 * @dfs_dir: direntry object of the UBI device debugfs directory
 * @dfs_chk_gen: debugfs knob to enable UBI general extra checks
 * @dfs_chk_io: debugfs knob to enable UBI I/O extra checks
 * @dfs_disable_bgt: debugfs knob to disable the background task
 * @dfs_emulate_bitflips: debugfs knob to emulate bit-flips
 * @dfs_emulate_io_failures: debugfs knob to emulate write/erase failures
 */
struct ubi_debug_info {
	unsigned int chk_gen:1;
	unsigned int chk_io:1;
	unsigned int disable_bgt:1;
	unsigned int emulate_bitflips:1;
	unsigned int emulate_io_failures:1;
	char dfs_dir_name[UBI_DFS_DIR_LEN + 1];
	struct dentry *dfs_dir;
	struct dentry *dfs_chk_gen;
	struct dentry *dfs_chk_io;
	struct dentry *dfs_disable_bgt;
	struct dentry *dfs_emulate_bitflips;
	struct dentry *dfs_emulate_io_failures;
};

/**
 * struct ubi_device - UBI device description structure
 * @dev: UBI device object to use the the Linux device model
 * @cdev: character device object to create character device
 * @ubi_num: UBI device number
 * @ubi_name: UBI device name
 * @vol_count: number of volumes in this UBI device
 * @volumes: volumes of this UBI device
 * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
 *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
 *                @vol->readers, @vol->writers, @vol->exclusive,
 *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
 * @ref_count: count of references on the UBI device
 * @image_seq: image sequence number recorded on EC headers
 *
 * @rsvd_pebs: count of reserved physical eraseblocks
 * @avail_pebs: count of available physical eraseblocks
 * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
 *                 handling
 * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
 *
 * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
 *                     of UBI initialization
 * @vtbl_slots: how many slots are available in the volume table
 * @vtbl_size: size of the volume table in bytes
 * @vtbl: in-RAM volume table copy
 * @device_mutex: protects on-flash volume table and serializes volume
 *                creation, deletion, update, re-size, re-name and set
 *                property
 *
 * @max_ec: current highest erase counter value
 * @mean_ec: current mean erase counter value
 *
 * @global_sqnum: global sequence number
 * @ltree_lock: protects the lock tree and @global_sqnum
 * @ltree: the lock tree
 * @alc_mutex: serializes "atomic LEB change" operations
 *
 * @fm_disabled: non-zero if fastmap is disabled (default)
 * @fm: in-memory data structure of the currently used fastmap
 * @fm_pool: in-memory data structure of the fastmap pool
 * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
 *		sub-system
 * @fm_mutex: serializes ubi_update_fastmap() and protects @fm_buf
 * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
 * @fm_size: fastmap size in bytes
 * @fm_sem: allows ubi_update_fastmap() to block EBA table changes
 * @fm_work: fastmap work queue
 *
 * @used: RB-tree of used physical eraseblocks
 * @erroneous: RB-tree of erroneous used physical eraseblocks
 * @free: RB-tree of free physical eraseblocks
 * @free_count: Contains the number of elements in @free
 * @scrub: RB-tree of physical eraseblocks which need scrubbing
 * @pq: protection queue (contain physical eraseblocks which are temporarily
 *      protected from the wear-leveling worker)
 * @pq_head: protection queue head
 * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
 *	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
 *	     @erroneous, and @erroneous_peb_count fields
 * @move_mutex: serializes eraseblock moves
 * @work_sem: synchronizes the WL worker with use tasks
 * @wl_scheduled: non-zero if the wear-leveling was scheduled
 * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
 *             physical eraseblock
 * @move_from: physical eraseblock from where the data is being moved
 * @move_to: physical eraseblock where the data is being moved to
 * @move_to_put: if the "to" PEB was put
 * @works: list of pending works
 * @works_count: count of pending works
 * @bgt_thread: background thread description object
 * @thread_enabled: if the background thread is enabled
 * @bgt_name: background thread name
 *
 * @flash_size: underlying MTD device size (in bytes)
 * @peb_count: count of physical eraseblocks on the MTD device
 * @peb_size: physical eraseblock size
 * @bad_peb_limit: top limit of expected bad physical eraseblocks
 * @bad_peb_count: count of bad physical eraseblocks
 * @good_peb_count: count of good physical eraseblocks
 * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
 *                  used by UBI)
 * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
 * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
 * @min_io_size: minimal input/output unit size of the underlying MTD device
 * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
 * @ro_mode: if the UBI device is in read-only mode
 * @leb_size: logical eraseblock size
 * @leb_start: starting offset of logical eraseblocks within physical
 *             eraseblocks
 * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
 * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
 * @vid_hdr_offset: starting offset of the volume identifier header (might be
 *                  unaligned)
 * @vid_hdr_aloffset: starting offset of the VID header aligned to
 * @hdrs_min_io_size
 * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
 * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
 *               not
 * @nor_flash: non-zero if working on top of NOR flash
 * @max_write_size: maximum amount of bytes the underlying flash can write at a
 *                  time (MTD write buffer size)
 * @mtd: MTD device descriptor
 *
 * @peb_buf: a buffer of PEB size used for different purposes
 * @buf_mutex: protects @peb_buf
 * @ckvol_mutex: serializes static volume checking when opening
 *
 * @dbg: debugging information for this UBI device
 */
struct ubi_device {
	struct cdev cdev;
	struct device dev;
	int ubi_num;
	char ubi_name[sizeof(UBI_NAME_STR)+5];
	int vol_count;
	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
	spinlock_t volumes_lock;
	int ref_count;
	int image_seq;

	int rsvd_pebs;
	int avail_pebs;
	int beb_rsvd_pebs;
	int beb_rsvd_level;
	int bad_peb_limit;

	int autoresize_vol_id;
	int vtbl_slots;
	int vtbl_size;
	struct ubi_vtbl_record *vtbl;
	struct mutex device_mutex;

	int max_ec;
	/* Note, mean_ec is not updated run-time - should be fixed */
	int mean_ec;

	/* EBA sub-system's stuff */
	unsigned long long global_sqnum;
	spinlock_t ltree_lock;
	struct rb_root ltree;
	struct mutex alc_mutex;

	/* Fastmap stuff */
	int fm_disabled;
	struct ubi_fastmap_layout *fm;
	struct ubi_fm_pool fm_pool;
	struct ubi_fm_pool fm_wl_pool;
	struct rw_semaphore fm_sem;
	struct mutex fm_mutex;
	void *fm_buf;
	size_t fm_size;
	struct work_struct fm_work;

	/* Wear-leveling sub-system's stuff */
	struct rb_root used;
	struct rb_root erroneous;
	struct rb_root free;
	int free_count;
	struct rb_root scrub;
	struct list_head pq[UBI_PROT_QUEUE_LEN];
	int pq_head;
	spinlock_t wl_lock;
	struct mutex move_mutex;
	struct rw_semaphore work_sem;
	int wl_scheduled;
	struct ubi_wl_entry **lookuptbl;
	struct ubi_wl_entry *move_from;
	struct ubi_wl_entry *move_to;
	int move_to_put;
	struct list_head works;
	int works_count;
	struct task_struct *bgt_thread;
	int thread_enabled;
	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];

	/* I/O sub-system's stuff */
	long long flash_size;
	int peb_count;
	int peb_size;
	int bad_peb_count;
	int good_peb_count;
	int corr_peb_count;
	int erroneous_peb_count;
	int max_erroneous;
	int min_io_size;
	int hdrs_min_io_size;
	int ro_mode;
	int leb_size;
	int leb_start;
	int ec_hdr_alsize;
	int vid_hdr_alsize;
	int vid_hdr_offset;
	int vid_hdr_aloffset;
	int vid_hdr_shift;
	unsigned int bad_allowed:1;
	unsigned int nor_flash:1;
	int max_write_size;
	struct mtd_info *mtd;

	void *peb_buf;
	struct mutex buf_mutex;
	struct mutex ckvol_mutex;

	struct ubi_debug_info dbg;
};

/**
 * struct ubi_ainf_peb - attach information about a physical eraseblock.
 * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
 * @pnum: physical eraseblock number
 * @vol_id: ID of the volume this LEB belongs to
 * @lnum: logical eraseblock number
 * @scrub: if this physical eraseblock needs scrubbing
 * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
 * @sqnum: sequence number
 * @u: unions RB-tree or @list links
 * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
 * @u.list: link in one of the eraseblock lists
 *
 * One object of this type is allocated for each physical eraseblock when
 * attaching an MTD device. Note, if this PEB does not belong to any LEB /
 * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
 */
struct ubi_ainf_peb {
	int ec;
	int pnum;
	int vol_id;
	int lnum;
	unsigned int scrub:1;
	unsigned int copy_flag:1;
	unsigned long long sqnum;
	union {
		struct rb_node rb;
		struct list_head list;
	} u;
};

/**
 * struct ubi_ainf_volume - attaching information about a volume.
 * @vol_id: volume ID
 * @highest_lnum: highest logical eraseblock number in this volume
 * @leb_count: number of logical eraseblocks in this volume
 * @vol_type: volume type
 * @used_ebs: number of used logical eraseblocks in this volume (only for
 *            static volumes)
 * @last_data_size: amount of data in the last logical eraseblock of this
 *                  volume (always equivalent to the usable logical eraseblock
 *                  size in case of dynamic volumes)
 * @data_pad: how many bytes at the end of logical eraseblocks of this volume
 *            are not used (due to volume alignment)
 * @compat: compatibility flags of this volume
 * @rb: link in the volume RB-tree
 * @root: root of the RB-tree containing all the eraseblock belonging to this
 *        volume (&struct ubi_ainf_peb objects)
 *
 * One object of this type is allocated for each volume when attaching an MTD
 * device.
 */
struct ubi_ainf_volume {
	int vol_id;
	int highest_lnum;
	int leb_count;
	int vol_type;
	int used_ebs;
	int last_data_size;
	int data_pad;
	int compat;
	struct rb_node rb;
	struct rb_root root;
};

/**
 * struct ubi_attach_info - MTD device attaching information.
 * @volumes: root of the volume RB-tree
 * @corr: list of corrupted physical eraseblocks
 * @free: list of free physical eraseblocks
 * @erase: list of physical eraseblocks which have to be erased
 * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
 *         those belonging to "preserve"-compatible internal volumes)
 * @corr_peb_count: count of PEBs in the @corr list
 * @empty_peb_count: count of PEBs which are presumably empty (contain only
 *                   0xFF bytes)
 * @alien_peb_count: count of PEBs in the @alien list
 * @bad_peb_count: count of bad physical eraseblocks
 * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
 *                       as bad yet, but which look like bad
 * @vols_found: number of volumes found
 * @highest_vol_id: highest volume ID
 * @is_empty: flag indicating whether the MTD device is empty or not
 * @min_ec: lowest erase counter value
 * @max_ec: highest erase counter value
 * @max_sqnum: highest sequence number value
 * @mean_ec: mean erase counter value
 * @ec_sum: a temporary variable used when calculating @mean_ec
 * @ec_count: a temporary variable used when calculating @mean_ec
 * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
 *
 * This data structure contains the result of attaching an MTD device and may
 * be used by other UBI sub-systems to build final UBI data structures, further
 * error-recovery and so on.
 */
struct ubi_attach_info {
	struct rb_root volumes;
	struct list_head corr;
	struct list_head free;
	struct list_head erase;
	struct list_head alien;
	int corr_peb_count;
	int empty_peb_count;
	int alien_peb_count;
	int bad_peb_count;
	int maybe_bad_peb_count;
	int vols_found;
	int highest_vol_id;
	int is_empty;
	int min_ec;
	int max_ec;
	unsigned long long max_sqnum;
	int mean_ec;
	uint64_t ec_sum;
	int ec_count;
	struct kmem_cache *aeb_slab_cache;
};

/**
 * struct ubi_work - UBI work description data structure.
 * @list: a link in the list of pending works
 * @func: worker function
 * @e: physical eraseblock to erase
 * @vol_id: the volume ID on which this erasure is being performed
 * @lnum: the logical eraseblock number
 * @torture: if the physical eraseblock has to be tortured
 * @anchor: produce a anchor PEB to by used by fastmap
 *
 * The @func pointer points to the worker function. If the @cancel argument is
 * not zero, the worker has to free the resources and exit immediately. The
 * worker has to return zero in case of success and a negative error code in
 * case of failure.
 */
struct ubi_work {
	struct list_head list;
	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int cancel);
	/* The below fields are only relevant to erasure works */
	struct ubi_wl_entry *e;
	int vol_id;
	int lnum;
	int torture;
	int anchor;
};

#include "debug.h"

extern struct kmem_cache *ubi_wl_entry_slab;
extern const struct file_operations ubi_ctrl_cdev_operations;
extern const struct file_operations ubi_cdev_operations;
extern const struct file_operations ubi_vol_cdev_operations;
extern struct class *ubi_class;
extern struct mutex ubi_devices_mutex;
extern struct blocking_notifier_head ubi_notifiers;

/* attach.c */
int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
				    int vol_id);
void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
				       struct ubi_attach_info *ai);
int ubi_attach(struct ubi_device *ubi, int force_scan);
void ubi_destroy_ai(struct ubi_attach_info *ai);

/* vtbl.c */
int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
			   struct ubi_vtbl_record *vtbl_rec);
int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
			    struct list_head *rename_list);
int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);

/* vmt.c */
int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);

/* upd.c */
int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
		     long long bytes);
int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
			 const void __user *buf, int count);
int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
			 const struct ubi_leb_change_req *req);
int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
			     const void __user *buf, int count);

/* misc.c */
int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
		      int length);
int ubi_check_volume(struct ubi_device *ubi, int vol_id);
void ubi_update_reserved(struct ubi_device *ubi);
void ubi_calculate_reserved(struct ubi_device *ubi);
int ubi_check_pattern(const void *buf, uint8_t patt, int size);

/* eba.c */
int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
		      int lnum);
int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
		     void *buf, int offset, int len, int check);
int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
		      const void *buf, int offset, int len);
int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
			 int lnum, const void *buf, int len, int used_ebs);
int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
			      int lnum, const void *buf, int len);
int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
		     struct ubi_vid_hdr *vid_hdr);
int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
		   struct ubi_attach_info *ai_scan);

/* wl.c */
int ubi_wl_get_peb(struct ubi_device *ubi);
int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
		   int pnum, int torture);
int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
void ubi_wl_close(struct ubi_device *ubi);
int ubi_thread(void *u);
struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
		      int lnum, int torture);
int ubi_is_erase_work(struct ubi_work *wrk);
void ubi_refill_pools(struct ubi_device *ubi);
int ubi_ensure_anchor_pebs(struct ubi_device *ubi);

/* io.c */
int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
		int len);
int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
		 int len);
int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
		       struct ubi_ec_hdr *ec_hdr, int verbose);
int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
			struct ubi_ec_hdr *ec_hdr);
int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
			struct ubi_vid_hdr *vid_hdr, int verbose);
int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
			 struct ubi_vid_hdr *vid_hdr);

/* build.c */
int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
		       int vid_hdr_offset, int max_beb_per1024);
int ubi_detach_mtd_dev(int ubi_num, int anyway);
struct ubi_device *ubi_get_device(int ubi_num);
void ubi_put_device(struct ubi_device *ubi);
struct ubi_device *ubi_get_by_major(int major);
int ubi_major2num(int major);
int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
		      int ntype);
int ubi_notify_all(struct ubi_device *ubi, int ntype,
		   struct notifier_block *nb);
int ubi_enumerate_volumes(struct notifier_block *nb);
void ubi_free_internal_volumes(struct ubi_device *ubi);

/* kapi.c */
void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
			    struct ubi_volume_info *vi);
/* scan.c */
int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
		      int pnum, const struct ubi_vid_hdr *vid_hdr);

/* fastmap.c */
size_t ubi_calc_fm_size(struct ubi_device *ubi);
int ubi_update_fastmap(struct ubi_device *ubi);
int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
		     int fm_anchor);

/* block.c */
#ifdef CONFIG_MTD_UBI_BLOCK
int ubiblock_init(void);
void ubiblock_exit(void);
int ubiblock_create(struct ubi_volume_info *vi);
int ubiblock_remove(struct ubi_volume_info *vi);
#else
static inline int ubiblock_init(void) { return 0; }
static inline void ubiblock_exit(void) {}
static inline int ubiblock_create(struct ubi_volume_info *vi)
{
	return -ENOSYS;
}
static inline int ubiblock_remove(struct ubi_volume_info *vi)
{
	return -ENOSYS;
}
#endif


/*
 * ubi_rb_for_each_entry - walk an RB-tree.
 * @rb: a pointer to type 'struct rb_node' to use as a loop counter
 * @pos: a pointer to RB-tree entry type to use as a loop counter
 * @root: RB-tree's root
 * @member: the name of the 'struct rb_node' within the RB-tree entry
 */
#define ubi_rb_for_each_entry(rb, pos, root, member)                         \
	for (rb = rb_first(root),                                            \
	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
	     rb;                                                             \
	     rb = rb_next(rb),                                               \
	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))

/*
 * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
 *
 * @av: volume attaching information
 * @aeb: attaching eraseblock information
 * @list: the list to move to
 */
static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
					 struct ubi_ainf_peb *aeb,
					 struct list_head *list)
{
		rb_erase(&aeb->u.rb, &av->root);
		list_add_tail(&aeb->u.list, list);
}

/**
 * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
 * @ubi: UBI device description object
 * @gfp_flags: GFP flags to allocate with
 *
 * This function returns a pointer to the newly allocated and zero-filled
 * volume identifier header object in case of success and %NULL in case of
 * failure.
 */
static inline struct ubi_vid_hdr *
ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
{
	void *vid_hdr;

	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
	if (!vid_hdr)
		return NULL;

	/*
	 * VID headers may be stored at un-aligned flash offsets, so we shift
	 * the pointer.
	 */
	return vid_hdr + ubi->vid_hdr_shift;
}

/**
 * ubi_free_vid_hdr - free a volume identifier header object.
 * @ubi: UBI device description object
 * @vid_hdr: the object to free
 */
static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
				    struct ubi_vid_hdr *vid_hdr)
{
	void *p = vid_hdr;

	if (!p)
		return;

	kfree(p - ubi->vid_hdr_shift);
}

/*
 * This function is equivalent to 'ubi_io_read()', but @offset is relative to
 * the beginning of the logical eraseblock, not to the beginning of the
 * physical eraseblock.
 */
static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
				   int pnum, int offset, int len)
{
	ubi_assert(offset >= 0);
	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
}

/*
 * This function is equivalent to 'ubi_io_write()', but @offset is relative to
 * the beginning of the logical eraseblock, not to the beginning of the
 * physical eraseblock.
 */
static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
				    int pnum, int offset, int len)
{
	ubi_assert(offset >= 0);
	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
}

/**
 * ubi_ro_mode - switch to read-only mode.
 * @ubi: UBI device description object
 */
static inline void ubi_ro_mode(struct ubi_device *ubi)
{
	if (!ubi->ro_mode) {
		ubi->ro_mode = 1;
		ubi_warn("switch to read-only mode");
		dump_stack();
	}
}

/**
 * vol_id2idx - get table index by volume ID.
 * @ubi: UBI device description object
 * @vol_id: volume ID
 */
static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
{
	if (vol_id >= UBI_INTERNAL_VOL_START)
		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
	else
		return vol_id;
}

/**
 * idx2vol_id - get volume ID by table index.
 * @ubi: UBI device description object
 * @idx: table index
 */
static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
{
	if (idx >= ubi->vtbl_slots)
		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
	else
		return idx;
}

#endif /* !__UBI_UBI_H__ */