]>
git.ipfire.org Git - thirdparty/u-boot.git/blob - drivers/mtd/ubi/wl.c
2 * Copyright (c) International Business Machines Corp., 2006
4 * SPDX-License-Identifier: GPL-2.0+
6 * Authors: Artem Bityutskiy (Битюцкий Артём), Thomas Gleixner
10 * UBI wear-leveling unit.
12 * This unit is responsible for wear-leveling. It works in terms of physical
13 * eraseblocks and erase counters and knows nothing about logical eraseblocks,
14 * volumes, etc. From this unit's perspective all physical eraseblocks are of
15 * two types - used and free. Used physical eraseblocks are those that were
16 * "get" by the 'ubi_wl_get_peb()' function, and free physical eraseblocks are
17 * those that were put by the 'ubi_wl_put_peb()' function.
19 * Physical eraseblocks returned by 'ubi_wl_get_peb()' have only erase counter
20 * header. The rest of the physical eraseblock contains only 0xFF bytes.
22 * When physical eraseblocks are returned to the WL unit by means of the
23 * 'ubi_wl_put_peb()' function, they are scheduled for erasure. The erasure is
24 * done asynchronously in context of the per-UBI device background thread,
25 * which is also managed by the WL unit.
27 * The wear-leveling is ensured by means of moving the contents of used
28 * physical eraseblocks with low erase counter to free physical eraseblocks
29 * with high erase counter.
31 * The 'ubi_wl_get_peb()' function accepts data type hints which help to pick
32 * an "optimal" physical eraseblock. For example, when it is known that the
33 * physical eraseblock will be "put" soon because it contains short-term data,
34 * the WL unit may pick a free physical eraseblock with low erase counter, and
37 * If the WL unit fails to erase a physical eraseblock, it marks it as bad.
39 * This unit is also responsible for scrubbing. If a bit-flip is detected in a
40 * physical eraseblock, it has to be moved. Technically this is the same as
41 * moving it for wear-leveling reasons.
43 * As it was said, for the UBI unit all physical eraseblocks are either "free"
44 * or "used". Free eraseblock are kept in the @wl->free RB-tree, while used
45 * eraseblocks are kept in a set of different RB-trees: @wl->used,
46 * @wl->prot.pnum, @wl->prot.aec, and @wl->scrub.
48 * Note, in this implementation, we keep a small in-RAM object for each physical
49 * eraseblock. This is surely not a scalable solution. But it appears to be good
50 * enough for moderately large flashes and it is simple. In future, one may
51 * re-work this unit and make it more scalable.
53 * At the moment this unit does not utilize the sequence number, which was
54 * introduced relatively recently. But it would be wise to do this because the
55 * sequence number of a logical eraseblock characterizes how old is it. For
56 * example, when we move a PEB with low erase counter, and we need to pick the
57 * target PEB, we pick a PEB with the highest EC if our PEB is "old" and we
58 * pick target PEB with an average EC if our PEB is not very "old". This is a
59 * room for future re-works of the WL unit.
61 * FIXME: looks too complex, should be simplified (later).
65 #include <linux/slab.h>
66 #include <linux/crc32.h>
67 #include <linux/freezer.h>
68 #include <linux/kthread.h>
71 #include <ubi_uboot.h>
74 /* Number of physical eraseblocks reserved for wear-leveling purposes */
75 #define WL_RESERVED_PEBS 1
78 * How many erase cycles are short term, unknown, and long term physical
79 * eraseblocks protected.
81 #define ST_PROTECTION 16
82 #define U_PROTECTION 10
83 #define LT_PROTECTION 4
86 * Maximum difference between two erase counters. If this threshold is
87 * exceeded, the WL unit starts moving data from used physical eraseblocks with
88 * low erase counter to free physical eraseblocks with high erase counter.
90 #define UBI_WL_THRESHOLD CONFIG_MTD_UBI_WL_THRESHOLD
93 * When a physical eraseblock is moved, the WL unit has to pick the target
94 * physical eraseblock to move to. The simplest way would be just to pick the
95 * one with the highest erase counter. But in certain workloads this could lead
96 * to an unlimited wear of one or few physical eraseblock. Indeed, imagine a
97 * situation when the picked physical eraseblock is constantly erased after the
98 * data is written to it. So, we have a constant which limits the highest erase
99 * counter of the free physical eraseblock to pick. Namely, the WL unit does
100 * not pick eraseblocks with erase counter greater then the lowest erase
101 * counter plus %WL_FREE_MAX_DIFF.
103 #define WL_FREE_MAX_DIFF (2*UBI_WL_THRESHOLD)
106 * Maximum number of consecutive background thread failures which is enough to
107 * switch to read-only mode.
109 #define WL_MAX_FAILURES 32
112 * struct ubi_wl_prot_entry - PEB protection entry.
113 * @rb_pnum: link in the @wl->prot.pnum RB-tree
114 * @rb_aec: link in the @wl->prot.aec RB-tree
115 * @abs_ec: the absolute erase counter value when the protection ends
116 * @e: the wear-leveling entry of the physical eraseblock under protection
118 * When the WL unit returns a physical eraseblock, the physical eraseblock is
119 * protected from being moved for some "time". For this reason, the physical
120 * eraseblock is not directly moved from the @wl->free tree to the @wl->used
121 * tree. There is one more tree in between where this physical eraseblock is
122 * temporarily stored (@wl->prot).
124 * All this protection stuff is needed because:
125 * o we don't want to move physical eraseblocks just after we have given them
126 * to the user; instead, we first want to let users fill them up with data;
128 * o there is a chance that the user will put the physical eraseblock very
129 * soon, so it makes sense not to move it for some time, but wait; this is
130 * especially important in case of "short term" physical eraseblocks.
132 * Physical eraseblocks stay protected only for limited time. But the "time" is
133 * measured in erase cycles in this case. This is implemented with help of the
134 * absolute erase counter (@wl->abs_ec). When it reaches certain value, the
135 * physical eraseblocks are moved from the protection trees (@wl->prot.*) to
136 * the @wl->used tree.
138 * Protected physical eraseblocks are searched by physical eraseblock number
139 * (when they are put) and by the absolute erase counter (to check if it is
140 * time to move them to the @wl->used tree). So there are actually 2 RB-trees
141 * storing the protected physical eraseblocks: @wl->prot.pnum and
142 * @wl->prot.aec. They are referred to as the "protection" trees. The
143 * first one is indexed by the physical eraseblock number. The second one is
144 * indexed by the absolute erase counter. Both trees store
145 * &struct ubi_wl_prot_entry objects.
147 * Each physical eraseblock has 2 main states: free and used. The former state
148 * corresponds to the @wl->free tree. The latter state is split up on several
150 * o the WL movement is allowed (@wl->used tree);
151 * o the WL movement is temporarily prohibited (@wl->prot.pnum and
152 * @wl->prot.aec trees);
153 * o scrubbing is needed (@wl->scrub tree).
155 * Depending on the sub-state, wear-leveling entries of the used physical
156 * eraseblocks may be kept in one of those trees.
158 struct ubi_wl_prot_entry
{
159 struct rb_node rb_pnum
;
160 struct rb_node rb_aec
;
161 unsigned long long abs_ec
;
162 struct ubi_wl_entry
*e
;
166 * struct ubi_work - UBI work description data structure.
167 * @list: a link in the list of pending works
168 * @func: worker function
169 * @priv: private data of the worker function
171 * @e: physical eraseblock to erase
172 * @torture: if the physical eraseblock has to be tortured
174 * The @func pointer points to the worker function. If the @cancel argument is
175 * not zero, the worker has to free the resources and exit immediately. The
176 * worker has to return zero in case of success and a negative error code in
180 struct list_head list
;
181 int (*func
)(struct ubi_device
*ubi
, struct ubi_work
*wrk
, int cancel
);
182 /* The below fields are only relevant to erasure works */
183 struct ubi_wl_entry
*e
;
187 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
188 static int paranoid_check_ec(struct ubi_device
*ubi
, int pnum
, int ec
);
189 static int paranoid_check_in_wl_tree(struct ubi_wl_entry
*e
,
190 struct rb_root
*root
);
192 #define paranoid_check_ec(ubi, pnum, ec) 0
193 #define paranoid_check_in_wl_tree(e, root)
197 * wl_tree_add - add a wear-leveling entry to a WL RB-tree.
198 * @e: the wear-leveling entry to add
199 * @root: the root of the tree
201 * Note, we use (erase counter, physical eraseblock number) pairs as keys in
202 * the @ubi->used and @ubi->free RB-trees.
204 static void wl_tree_add(struct ubi_wl_entry
*e
, struct rb_root
*root
)
206 struct rb_node
**p
, *parent
= NULL
;
210 struct ubi_wl_entry
*e1
;
213 e1
= rb_entry(parent
, struct ubi_wl_entry
, rb
);
217 else if (e
->ec
> e1
->ec
)
220 ubi_assert(e
->pnum
!= e1
->pnum
);
221 if (e
->pnum
< e1
->pnum
)
228 rb_link_node(&e
->rb
, parent
, p
);
229 rb_insert_color(&e
->rb
, root
);
233 * do_work - do one pending work.
234 * @ubi: UBI device description object
236 * This function returns zero in case of success and a negative error code in
239 static int do_work(struct ubi_device
*ubi
)
242 struct ubi_work
*wrk
;
247 * @ubi->work_sem is used to synchronize with the workers. Workers take
248 * it in read mode, so many of them may be doing works at a time. But
249 * the queue flush code has to be sure the whole queue of works is
250 * done, and it takes the mutex in write mode.
252 down_read(&ubi
->work_sem
);
253 spin_lock(&ubi
->wl_lock
);
254 if (list_empty(&ubi
->works
)) {
255 spin_unlock(&ubi
->wl_lock
);
256 up_read(&ubi
->work_sem
);
260 wrk
= list_entry(ubi
->works
.next
, struct ubi_work
, list
);
261 list_del(&wrk
->list
);
262 ubi
->works_count
-= 1;
263 ubi_assert(ubi
->works_count
>= 0);
264 spin_unlock(&ubi
->wl_lock
);
267 * Call the worker function. Do not touch the work structure
268 * after this call as it will have been freed or reused by that
269 * time by the worker function.
271 err
= wrk
->func(ubi
, wrk
, 0);
273 ubi_err("work failed with error code %d", err
);
274 up_read(&ubi
->work_sem
);
280 * produce_free_peb - produce a free physical eraseblock.
281 * @ubi: UBI device description object
283 * This function tries to make a free PEB by means of synchronous execution of
284 * pending works. This may be needed if, for example the background thread is
285 * disabled. Returns zero in case of success and a negative error code in case
288 static int produce_free_peb(struct ubi_device
*ubi
)
292 spin_lock(&ubi
->wl_lock
);
293 while (!ubi
->free
.rb_node
) {
294 spin_unlock(&ubi
->wl_lock
);
296 dbg_wl("do one work synchronously");
301 spin_lock(&ubi
->wl_lock
);
303 spin_unlock(&ubi
->wl_lock
);
309 * in_wl_tree - check if wear-leveling entry is present in a WL RB-tree.
310 * @e: the wear-leveling entry to check
311 * @root: the root of the tree
313 * This function returns non-zero if @e is in the @root RB-tree and zero if it
316 static int in_wl_tree(struct ubi_wl_entry
*e
, struct rb_root
*root
)
322 struct ubi_wl_entry
*e1
;
324 e1
= rb_entry(p
, struct ubi_wl_entry
, rb
);
326 if (e
->pnum
== e1
->pnum
) {
333 else if (e
->ec
> e1
->ec
)
336 ubi_assert(e
->pnum
!= e1
->pnum
);
337 if (e
->pnum
< e1
->pnum
)
348 * prot_tree_add - add physical eraseblock to protection trees.
349 * @ubi: UBI device description object
350 * @e: the physical eraseblock to add
351 * @pe: protection entry object to use
352 * @abs_ec: absolute erase counter value when this physical eraseblock has
353 * to be removed from the protection trees.
355 * @wl->lock has to be locked.
357 static void prot_tree_add(struct ubi_device
*ubi
, struct ubi_wl_entry
*e
,
358 struct ubi_wl_prot_entry
*pe
, int abs_ec
)
360 struct rb_node
**p
, *parent
= NULL
;
361 struct ubi_wl_prot_entry
*pe1
;
364 pe
->abs_ec
= ubi
->abs_ec
+ abs_ec
;
366 p
= &ubi
->prot
.pnum
.rb_node
;
369 pe1
= rb_entry(parent
, struct ubi_wl_prot_entry
, rb_pnum
);
371 if (e
->pnum
< pe1
->e
->pnum
)
376 rb_link_node(&pe
->rb_pnum
, parent
, p
);
377 rb_insert_color(&pe
->rb_pnum
, &ubi
->prot
.pnum
);
379 p
= &ubi
->prot
.aec
.rb_node
;
383 pe1
= rb_entry(parent
, struct ubi_wl_prot_entry
, rb_aec
);
385 if (pe
->abs_ec
< pe1
->abs_ec
)
390 rb_link_node(&pe
->rb_aec
, parent
, p
);
391 rb_insert_color(&pe
->rb_aec
, &ubi
->prot
.aec
);
395 * find_wl_entry - find wear-leveling entry closest to certain erase counter.
396 * @root: the RB-tree where to look for
397 * @max: highest possible erase counter
399 * This function looks for a wear leveling entry with erase counter closest to
400 * @max and less then @max.
402 static struct ubi_wl_entry
*find_wl_entry(struct rb_root
*root
, int max
)
405 struct ubi_wl_entry
*e
;
407 e
= rb_entry(rb_first(root
), struct ubi_wl_entry
, rb
);
412 struct ubi_wl_entry
*e1
;
414 e1
= rb_entry(p
, struct ubi_wl_entry
, rb
);
427 * ubi_wl_get_peb - get a physical eraseblock.
428 * @ubi: UBI device description object
429 * @dtype: type of data which will be stored in this physical eraseblock
431 * This function returns a physical eraseblock in case of success and a
432 * negative error code in case of failure. Might sleep.
434 int ubi_wl_get_peb(struct ubi_device
*ubi
, int dtype
)
436 int err
, protect
, medium_ec
;
437 struct ubi_wl_entry
*e
, *first
, *last
;
438 struct ubi_wl_prot_entry
*pe
;
440 ubi_assert(dtype
== UBI_LONGTERM
|| dtype
== UBI_SHORTTERM
||
441 dtype
== UBI_UNKNOWN
);
443 pe
= kmalloc(sizeof(struct ubi_wl_prot_entry
), GFP_NOFS
);
448 spin_lock(&ubi
->wl_lock
);
449 if (!ubi
->free
.rb_node
) {
450 if (ubi
->works_count
== 0) {
451 ubi_assert(list_empty(&ubi
->works
));
452 ubi_err("no free eraseblocks");
453 spin_unlock(&ubi
->wl_lock
);
457 spin_unlock(&ubi
->wl_lock
);
459 err
= produce_free_peb(ubi
);
470 * For long term data we pick a physical eraseblock
471 * with high erase counter. But the highest erase
472 * counter we can pick is bounded by the the lowest
473 * erase counter plus %WL_FREE_MAX_DIFF.
475 e
= find_wl_entry(&ubi
->free
, WL_FREE_MAX_DIFF
);
476 protect
= LT_PROTECTION
;
480 * For unknown data we pick a physical eraseblock with
481 * medium erase counter. But we by no means can pick a
482 * physical eraseblock with erase counter greater or
483 * equivalent than the lowest erase counter plus
486 first
= rb_entry(rb_first(&ubi
->free
),
487 struct ubi_wl_entry
, rb
);
488 last
= rb_entry(rb_last(&ubi
->free
),
489 struct ubi_wl_entry
, rb
);
491 if (last
->ec
- first
->ec
< WL_FREE_MAX_DIFF
)
492 e
= rb_entry(ubi
->free
.rb_node
,
493 struct ubi_wl_entry
, rb
);
495 medium_ec
= (first
->ec
+ WL_FREE_MAX_DIFF
)/2;
496 e
= find_wl_entry(&ubi
->free
, medium_ec
);
498 protect
= U_PROTECTION
;
502 * For short term data we pick a physical eraseblock
503 * with the lowest erase counter as we expect it will
506 e
= rb_entry(rb_first(&ubi
->free
),
507 struct ubi_wl_entry
, rb
);
508 protect
= ST_PROTECTION
;
517 * Move the physical eraseblock to the protection trees where it will
518 * be protected from being moved for some time.
520 paranoid_check_in_wl_tree(e
, &ubi
->free
);
521 rb_erase(&e
->rb
, &ubi
->free
);
522 prot_tree_add(ubi
, e
, pe
, protect
);
524 dbg_wl("PEB %d EC %d, protection %d", e
->pnum
, e
->ec
, protect
);
525 spin_unlock(&ubi
->wl_lock
);
531 * prot_tree_del - remove a physical eraseblock from the protection trees
532 * @ubi: UBI device description object
533 * @pnum: the physical eraseblock to remove
535 * This function returns PEB @pnum from the protection trees and returns zero
536 * in case of success and %-ENODEV if the PEB was not found in the protection
539 static int prot_tree_del(struct ubi_device
*ubi
, int pnum
)
542 struct ubi_wl_prot_entry
*pe
= NULL
;
544 p
= ubi
->prot
.pnum
.rb_node
;
547 pe
= rb_entry(p
, struct ubi_wl_prot_entry
, rb_pnum
);
549 if (pnum
== pe
->e
->pnum
)
552 if (pnum
< pe
->e
->pnum
)
561 ubi_assert(pe
->e
->pnum
== pnum
);
562 rb_erase(&pe
->rb_aec
, &ubi
->prot
.aec
);
563 rb_erase(&pe
->rb_pnum
, &ubi
->prot
.pnum
);
569 * sync_erase - synchronously erase a physical eraseblock.
570 * @ubi: UBI device description object
571 * @e: the the physical eraseblock to erase
572 * @torture: if the physical eraseblock has to be tortured
574 * This function returns zero in case of success and a negative error code in
577 static int sync_erase(struct ubi_device
*ubi
, struct ubi_wl_entry
*e
, int torture
)
580 struct ubi_ec_hdr
*ec_hdr
;
581 unsigned long long ec
= e
->ec
;
583 dbg_wl("erase PEB %d, old EC %llu", e
->pnum
, ec
);
585 err
= paranoid_check_ec(ubi
, e
->pnum
, e
->ec
);
589 ec_hdr
= kzalloc(ubi
->ec_hdr_alsize
, GFP_NOFS
);
593 err
= ubi_io_sync_erase(ubi
, e
->pnum
, torture
);
598 if (ec
> UBI_MAX_ERASECOUNTER
) {
600 * Erase counter overflow. Upgrade UBI and use 64-bit
601 * erase counters internally.
603 ubi_err("erase counter overflow at PEB %d, EC %llu",
609 dbg_wl("erased PEB %d, new EC %llu", e
->pnum
, ec
);
611 ec_hdr
->ec
= cpu_to_be64(ec
);
613 err
= ubi_io_write_ec_hdr(ubi
, e
->pnum
, ec_hdr
);
618 spin_lock(&ubi
->wl_lock
);
619 if (e
->ec
> ubi
->max_ec
)
621 spin_unlock(&ubi
->wl_lock
);
629 * check_protection_over - check if it is time to stop protecting some
630 * physical eraseblocks.
631 * @ubi: UBI device description object
633 * This function is called after each erase operation, when the absolute erase
634 * counter is incremented, to check if some physical eraseblock have not to be
635 * protected any longer. These physical eraseblocks are moved from the
636 * protection trees to the used tree.
638 static void check_protection_over(struct ubi_device
*ubi
)
640 struct ubi_wl_prot_entry
*pe
;
643 * There may be several protected physical eraseblock to remove,
647 spin_lock(&ubi
->wl_lock
);
648 if (!ubi
->prot
.aec
.rb_node
) {
649 spin_unlock(&ubi
->wl_lock
);
653 pe
= rb_entry(rb_first(&ubi
->prot
.aec
),
654 struct ubi_wl_prot_entry
, rb_aec
);
656 if (pe
->abs_ec
> ubi
->abs_ec
) {
657 spin_unlock(&ubi
->wl_lock
);
661 dbg_wl("PEB %d protection over, abs_ec %llu, PEB abs_ec %llu",
662 pe
->e
->pnum
, ubi
->abs_ec
, pe
->abs_ec
);
663 rb_erase(&pe
->rb_aec
, &ubi
->prot
.aec
);
664 rb_erase(&pe
->rb_pnum
, &ubi
->prot
.pnum
);
665 wl_tree_add(pe
->e
, &ubi
->used
);
666 spin_unlock(&ubi
->wl_lock
);
674 * schedule_ubi_work - schedule a work.
675 * @ubi: UBI device description object
676 * @wrk: the work to schedule
678 * This function enqueues a work defined by @wrk to the tail of the pending
681 static void schedule_ubi_work(struct ubi_device
*ubi
, struct ubi_work
*wrk
)
683 spin_lock(&ubi
->wl_lock
);
684 list_add_tail(&wrk
->list
, &ubi
->works
);
685 ubi_assert(ubi
->works_count
>= 0);
686 ubi
->works_count
+= 1;
689 * U-Boot special: We have no bgt_thread in U-Boot!
690 * So just call do_work() here directly.
694 spin_unlock(&ubi
->wl_lock
);
697 static int erase_worker(struct ubi_device
*ubi
, struct ubi_work
*wl_wrk
,
701 * schedule_erase - schedule an erase work.
702 * @ubi: UBI device description object
703 * @e: the WL entry of the physical eraseblock to erase
704 * @torture: if the physical eraseblock has to be tortured
706 * This function returns zero in case of success and a %-ENOMEM in case of
709 static int schedule_erase(struct ubi_device
*ubi
, struct ubi_wl_entry
*e
,
712 struct ubi_work
*wl_wrk
;
714 dbg_wl("schedule erasure of PEB %d, EC %d, torture %d",
715 e
->pnum
, e
->ec
, torture
);
717 wl_wrk
= kmalloc(sizeof(struct ubi_work
), GFP_NOFS
);
721 wl_wrk
->func
= &erase_worker
;
723 wl_wrk
->torture
= torture
;
725 schedule_ubi_work(ubi
, wl_wrk
);
730 * wear_leveling_worker - wear-leveling worker function.
731 * @ubi: UBI device description object
732 * @wrk: the work object
733 * @cancel: non-zero if the worker has to free memory and exit
735 * This function copies a more worn out physical eraseblock to a less worn out
736 * one. Returns zero in case of success and a negative error code in case of
739 static int wear_leveling_worker(struct ubi_device
*ubi
, struct ubi_work
*wrk
,
742 int err
, put
= 0, scrubbing
= 0, protect
= 0;
743 struct ubi_wl_prot_entry
*uninitialized_var(pe
);
744 struct ubi_wl_entry
*e1
, *e2
;
745 struct ubi_vid_hdr
*vid_hdr
;
752 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
756 mutex_lock(&ubi
->move_mutex
);
757 spin_lock(&ubi
->wl_lock
);
758 ubi_assert(!ubi
->move_from
&& !ubi
->move_to
);
759 ubi_assert(!ubi
->move_to_put
);
761 if (!ubi
->free
.rb_node
||
762 (!ubi
->used
.rb_node
&& !ubi
->scrub
.rb_node
)) {
764 * No free physical eraseblocks? Well, they must be waiting in
765 * the queue to be erased. Cancel movement - it will be
766 * triggered again when a free physical eraseblock appears.
768 * No used physical eraseblocks? They must be temporarily
769 * protected from being moved. They will be moved to the
770 * @ubi->used tree later and the wear-leveling will be
773 dbg_wl("cancel WL, a list is empty: free %d, used %d",
774 !ubi
->free
.rb_node
, !ubi
->used
.rb_node
);
778 if (!ubi
->scrub
.rb_node
) {
780 * Now pick the least worn-out used physical eraseblock and a
781 * highly worn-out free physical eraseblock. If the erase
782 * counters differ much enough, start wear-leveling.
784 e1
= rb_entry(rb_first(&ubi
->used
), struct ubi_wl_entry
, rb
);
785 e2
= find_wl_entry(&ubi
->free
, WL_FREE_MAX_DIFF
);
787 if (!(e2
->ec
- e1
->ec
>= UBI_WL_THRESHOLD
)) {
788 dbg_wl("no WL needed: min used EC %d, max free EC %d",
792 paranoid_check_in_wl_tree(e1
, &ubi
->used
);
793 rb_erase(&e1
->rb
, &ubi
->used
);
794 dbg_wl("move PEB %d EC %d to PEB %d EC %d",
795 e1
->pnum
, e1
->ec
, e2
->pnum
, e2
->ec
);
797 /* Perform scrubbing */
799 e1
= rb_entry(rb_first(&ubi
->scrub
), struct ubi_wl_entry
, rb
);
800 e2
= find_wl_entry(&ubi
->free
, WL_FREE_MAX_DIFF
);
801 paranoid_check_in_wl_tree(e1
, &ubi
->scrub
);
802 rb_erase(&e1
->rb
, &ubi
->scrub
);
803 dbg_wl("scrub PEB %d to PEB %d", e1
->pnum
, e2
->pnum
);
806 paranoid_check_in_wl_tree(e2
, &ubi
->free
);
807 rb_erase(&e2
->rb
, &ubi
->free
);
810 spin_unlock(&ubi
->wl_lock
);
813 * Now we are going to copy physical eraseblock @e1->pnum to @e2->pnum.
814 * We so far do not know which logical eraseblock our physical
815 * eraseblock (@e1) belongs to. We have to read the volume identifier
818 * Note, we are protected from this PEB being unmapped and erased. The
819 * 'ubi_wl_put_peb()' would wait for moving to be finished if the PEB
820 * which is being moved was unmapped.
823 err
= ubi_io_read_vid_hdr(ubi
, e1
->pnum
, vid_hdr
, 0);
824 if (err
&& err
!= UBI_IO_BITFLIPS
) {
825 if (err
== UBI_IO_PEB_FREE
) {
827 * We are trying to move PEB without a VID header. UBI
828 * always write VID headers shortly after the PEB was
829 * given, so we have a situation when it did not have
830 * chance to write it down because it was preempted.
831 * Just re-schedule the work, so that next time it will
832 * likely have the VID header in place.
834 dbg_wl("PEB %d has no VID header", e1
->pnum
);
838 ubi_err("error %d while reading VID header from PEB %d",
845 err
= ubi_eba_copy_leb(ubi
, e1
->pnum
, e2
->pnum
, vid_hdr
);
854 * For some reason the LEB was not moved - it might be because
855 * the volume is being deleted. We should prevent this PEB from
856 * being selected for wear-levelling movement for some "time",
857 * so put it to the protection tree.
860 dbg_wl("cancelled moving PEB %d", e1
->pnum
);
861 pe
= kmalloc(sizeof(struct ubi_wl_prot_entry
), GFP_NOFS
);
870 ubi_free_vid_hdr(ubi
, vid_hdr
);
871 spin_lock(&ubi
->wl_lock
);
873 prot_tree_add(ubi
, e1
, pe
, protect
);
874 if (!ubi
->move_to_put
)
875 wl_tree_add(e2
, &ubi
->used
);
878 ubi
->move_from
= ubi
->move_to
= NULL
;
879 ubi
->move_to_put
= ubi
->wl_scheduled
= 0;
880 spin_unlock(&ubi
->wl_lock
);
884 * Well, the target PEB was put meanwhile, schedule it for
887 dbg_wl("PEB %d was put meanwhile, erase", e2
->pnum
);
888 err
= schedule_erase(ubi
, e2
, 0);
894 err
= schedule_erase(ubi
, e1
, 0);
901 mutex_unlock(&ubi
->move_mutex
);
905 * For some reasons the LEB was not moved, might be an error, might be
906 * something else. @e1 was not changed, so return it back. @e2 might
907 * be changed, schedule it for erasure.
910 ubi_free_vid_hdr(ubi
, vid_hdr
);
911 spin_lock(&ubi
->wl_lock
);
913 wl_tree_add(e1
, &ubi
->scrub
);
915 wl_tree_add(e1
, &ubi
->used
);
916 ubi
->move_from
= ubi
->move_to
= NULL
;
917 ubi
->move_to_put
= ubi
->wl_scheduled
= 0;
918 spin_unlock(&ubi
->wl_lock
);
920 err
= schedule_erase(ubi
, e2
, 0);
924 mutex_unlock(&ubi
->move_mutex
);
928 ubi_err("error %d while moving PEB %d to PEB %d",
929 err
, e1
->pnum
, e2
->pnum
);
931 ubi_free_vid_hdr(ubi
, vid_hdr
);
932 spin_lock(&ubi
->wl_lock
);
933 ubi
->move_from
= ubi
->move_to
= NULL
;
934 ubi
->move_to_put
= ubi
->wl_scheduled
= 0;
935 spin_unlock(&ubi
->wl_lock
);
937 kmem_cache_free(ubi_wl_entry_slab
, e1
);
938 kmem_cache_free(ubi_wl_entry_slab
, e2
);
941 mutex_unlock(&ubi
->move_mutex
);
945 ubi
->wl_scheduled
= 0;
946 spin_unlock(&ubi
->wl_lock
);
947 mutex_unlock(&ubi
->move_mutex
);
948 ubi_free_vid_hdr(ubi
, vid_hdr
);
953 * ensure_wear_leveling - schedule wear-leveling if it is needed.
954 * @ubi: UBI device description object
956 * This function checks if it is time to start wear-leveling and schedules it
957 * if yes. This function returns zero in case of success and a negative error
958 * code in case of failure.
960 static int ensure_wear_leveling(struct ubi_device
*ubi
)
963 struct ubi_wl_entry
*e1
;
964 struct ubi_wl_entry
*e2
;
965 struct ubi_work
*wrk
;
967 spin_lock(&ubi
->wl_lock
);
968 if (ubi
->wl_scheduled
)
969 /* Wear-leveling is already in the work queue */
973 * If the ubi->scrub tree is not empty, scrubbing is needed, and the
974 * the WL worker has to be scheduled anyway.
976 if (!ubi
->scrub
.rb_node
) {
977 if (!ubi
->used
.rb_node
|| !ubi
->free
.rb_node
)
978 /* No physical eraseblocks - no deal */
982 * We schedule wear-leveling only if the difference between the
983 * lowest erase counter of used physical eraseblocks and a high
984 * erase counter of free physical eraseblocks is greater then
987 e1
= rb_entry(rb_first(&ubi
->used
), struct ubi_wl_entry
, rb
);
988 e2
= find_wl_entry(&ubi
->free
, WL_FREE_MAX_DIFF
);
990 if (!(e2
->ec
- e1
->ec
>= UBI_WL_THRESHOLD
))
992 dbg_wl("schedule wear-leveling");
994 dbg_wl("schedule scrubbing");
996 ubi
->wl_scheduled
= 1;
997 spin_unlock(&ubi
->wl_lock
);
999 wrk
= kmalloc(sizeof(struct ubi_work
), GFP_NOFS
);
1005 wrk
->func
= &wear_leveling_worker
;
1006 schedule_ubi_work(ubi
, wrk
);
1010 spin_lock(&ubi
->wl_lock
);
1011 ubi
->wl_scheduled
= 0;
1013 spin_unlock(&ubi
->wl_lock
);
1018 * erase_worker - physical eraseblock erase worker function.
1019 * @ubi: UBI device description object
1020 * @wl_wrk: the work object
1021 * @cancel: non-zero if the worker has to free memory and exit
1023 * This function erases a physical eraseblock and perform torture testing if
1024 * needed. It also takes care about marking the physical eraseblock bad if
1025 * needed. Returns zero in case of success and a negative error code in case of
1028 static int erase_worker(struct ubi_device
*ubi
, struct ubi_work
*wl_wrk
,
1031 struct ubi_wl_entry
*e
= wl_wrk
->e
;
1032 int pnum
= e
->pnum
, err
, need
;
1035 dbg_wl("cancel erasure of PEB %d EC %d", pnum
, e
->ec
);
1037 kmem_cache_free(ubi_wl_entry_slab
, e
);
1041 dbg_wl("erase PEB %d EC %d", pnum
, e
->ec
);
1043 err
= sync_erase(ubi
, e
, wl_wrk
->torture
);
1045 /* Fine, we've erased it successfully */
1048 spin_lock(&ubi
->wl_lock
);
1050 wl_tree_add(e
, &ubi
->free
);
1051 spin_unlock(&ubi
->wl_lock
);
1054 * One more erase operation has happened, take care about protected
1055 * physical eraseblocks.
1057 check_protection_over(ubi
);
1059 /* And take care about wear-leveling */
1060 err
= ensure_wear_leveling(ubi
);
1064 ubi_err("failed to erase PEB %d, error %d", pnum
, err
);
1066 kmem_cache_free(ubi_wl_entry_slab
, e
);
1068 if (err
== -EINTR
|| err
== -ENOMEM
|| err
== -EAGAIN
||
1072 /* Re-schedule the LEB for erasure */
1073 err1
= schedule_erase(ubi
, e
, 0);
1079 } else if (err
!= -EIO
) {
1081 * If this is not %-EIO, we have no idea what to do. Scheduling
1082 * this physical eraseblock for erasure again would cause
1083 * errors again and again. Well, lets switch to RO mode.
1088 /* It is %-EIO, the PEB went bad */
1090 if (!ubi
->bad_allowed
) {
1091 ubi_err("bad physical eraseblock %d detected", pnum
);
1095 spin_lock(&ubi
->volumes_lock
);
1096 need
= ubi
->beb_rsvd_level
- ubi
->beb_rsvd_pebs
+ 1;
1098 need
= ubi
->avail_pebs
>= need
? need
: ubi
->avail_pebs
;
1099 ubi
->avail_pebs
-= need
;
1100 ubi
->rsvd_pebs
+= need
;
1101 ubi
->beb_rsvd_pebs
+= need
;
1103 ubi_msg("reserve more %d PEBs", need
);
1106 if (ubi
->beb_rsvd_pebs
== 0) {
1107 spin_unlock(&ubi
->volumes_lock
);
1108 ubi_err("no reserved physical eraseblocks");
1112 spin_unlock(&ubi
->volumes_lock
);
1113 ubi_msg("mark PEB %d as bad", pnum
);
1115 err
= ubi_io_mark_bad(ubi
, pnum
);
1119 spin_lock(&ubi
->volumes_lock
);
1120 ubi
->beb_rsvd_pebs
-= 1;
1121 ubi
->bad_peb_count
+= 1;
1122 ubi
->good_peb_count
-= 1;
1123 ubi_calculate_reserved(ubi
);
1124 if (ubi
->beb_rsvd_pebs
== 0)
1125 ubi_warn("last PEB from the reserved pool was used");
1126 spin_unlock(&ubi
->volumes_lock
);
1136 * ubi_wl_put_peb - return a physical eraseblock to the wear-leveling unit.
1137 * @ubi: UBI device description object
1138 * @pnum: physical eraseblock to return
1139 * @torture: if this physical eraseblock has to be tortured
1141 * This function is called to return physical eraseblock @pnum to the pool of
1142 * free physical eraseblocks. The @torture flag has to be set if an I/O error
1143 * occurred to this @pnum and it has to be tested. This function returns zero
1144 * in case of success, and a negative error code in case of failure.
1146 int ubi_wl_put_peb(struct ubi_device
*ubi
, int pnum
, int torture
)
1149 struct ubi_wl_entry
*e
;
1151 dbg_wl("PEB %d", pnum
);
1152 ubi_assert(pnum
>= 0);
1153 ubi_assert(pnum
< ubi
->peb_count
);
1156 spin_lock(&ubi
->wl_lock
);
1157 e
= ubi
->lookuptbl
[pnum
];
1158 if (e
== ubi
->move_from
) {
1160 * User is putting the physical eraseblock which was selected to
1161 * be moved. It will be scheduled for erasure in the
1162 * wear-leveling worker.
1164 dbg_wl("PEB %d is being moved, wait", pnum
);
1165 spin_unlock(&ubi
->wl_lock
);
1167 /* Wait for the WL worker by taking the @ubi->move_mutex */
1168 mutex_lock(&ubi
->move_mutex
);
1169 mutex_unlock(&ubi
->move_mutex
);
1171 } else if (e
== ubi
->move_to
) {
1173 * User is putting the physical eraseblock which was selected
1174 * as the target the data is moved to. It may happen if the EBA
1175 * unit already re-mapped the LEB in 'ubi_eba_copy_leb()' but
1176 * the WL unit has not put the PEB to the "used" tree yet, but
1177 * it is about to do this. So we just set a flag which will
1178 * tell the WL worker that the PEB is not needed anymore and
1179 * should be scheduled for erasure.
1181 dbg_wl("PEB %d is the target of data moving", pnum
);
1182 ubi_assert(!ubi
->move_to_put
);
1183 ubi
->move_to_put
= 1;
1184 spin_unlock(&ubi
->wl_lock
);
1187 if (in_wl_tree(e
, &ubi
->used
)) {
1188 paranoid_check_in_wl_tree(e
, &ubi
->used
);
1189 rb_erase(&e
->rb
, &ubi
->used
);
1190 } else if (in_wl_tree(e
, &ubi
->scrub
)) {
1191 paranoid_check_in_wl_tree(e
, &ubi
->scrub
);
1192 rb_erase(&e
->rb
, &ubi
->scrub
);
1194 err
= prot_tree_del(ubi
, e
->pnum
);
1196 ubi_err("PEB %d not found", pnum
);
1198 spin_unlock(&ubi
->wl_lock
);
1203 spin_unlock(&ubi
->wl_lock
);
1205 err
= schedule_erase(ubi
, e
, torture
);
1207 spin_lock(&ubi
->wl_lock
);
1208 wl_tree_add(e
, &ubi
->used
);
1209 spin_unlock(&ubi
->wl_lock
);
1216 * ubi_wl_scrub_peb - schedule a physical eraseblock for scrubbing.
1217 * @ubi: UBI device description object
1218 * @pnum: the physical eraseblock to schedule
1220 * If a bit-flip in a physical eraseblock is detected, this physical eraseblock
1221 * needs scrubbing. This function schedules a physical eraseblock for
1222 * scrubbing which is done in background. This function returns zero in case of
1223 * success and a negative error code in case of failure.
1225 int ubi_wl_scrub_peb(struct ubi_device
*ubi
, int pnum
)
1227 struct ubi_wl_entry
*e
;
1229 ubi_msg("schedule PEB %d for scrubbing", pnum
);
1232 spin_lock(&ubi
->wl_lock
);
1233 e
= ubi
->lookuptbl
[pnum
];
1234 if (e
== ubi
->move_from
|| in_wl_tree(e
, &ubi
->scrub
)) {
1235 spin_unlock(&ubi
->wl_lock
);
1239 if (e
== ubi
->move_to
) {
1241 * This physical eraseblock was used to move data to. The data
1242 * was moved but the PEB was not yet inserted to the proper
1243 * tree. We should just wait a little and let the WL worker
1246 spin_unlock(&ubi
->wl_lock
);
1247 dbg_wl("the PEB %d is not in proper tree, retry", pnum
);
1252 if (in_wl_tree(e
, &ubi
->used
)) {
1253 paranoid_check_in_wl_tree(e
, &ubi
->used
);
1254 rb_erase(&e
->rb
, &ubi
->used
);
1258 err
= prot_tree_del(ubi
, e
->pnum
);
1260 ubi_err("PEB %d not found", pnum
);
1262 spin_unlock(&ubi
->wl_lock
);
1267 wl_tree_add(e
, &ubi
->scrub
);
1268 spin_unlock(&ubi
->wl_lock
);
1271 * Technically scrubbing is the same as wear-leveling, so it is done
1274 return ensure_wear_leveling(ubi
);
1278 * ubi_wl_flush - flush all pending works.
1279 * @ubi: UBI device description object
1281 * This function returns zero in case of success and a negative error code in
1284 int ubi_wl_flush(struct ubi_device
*ubi
)
1289 * Erase while the pending works queue is not empty, but not more then
1290 * the number of currently pending works.
1292 dbg_wl("flush (%d pending works)", ubi
->works_count
);
1293 while (ubi
->works_count
) {
1300 * Make sure all the works which have been done in parallel are
1303 down_write(&ubi
->work_sem
);
1304 up_write(&ubi
->work_sem
);
1307 * And in case last was the WL worker and it cancelled the LEB
1308 * movement, flush again.
1310 while (ubi
->works_count
) {
1311 dbg_wl("flush more (%d pending works)", ubi
->works_count
);
1321 * tree_destroy - destroy an RB-tree.
1322 * @root: the root of the tree to destroy
1324 static void tree_destroy(struct rb_root
*root
)
1327 struct ubi_wl_entry
*e
;
1333 else if (rb
->rb_right
)
1336 e
= rb_entry(rb
, struct ubi_wl_entry
, rb
);
1340 if (rb
->rb_left
== &e
->rb
)
1343 rb
->rb_right
= NULL
;
1346 kmem_cache_free(ubi_wl_entry_slab
, e
);
1352 * ubi_thread - UBI background thread.
1353 * @u: the UBI device description object pointer
1355 int ubi_thread(void *u
)
1358 struct ubi_device
*ubi
= u
;
1360 ubi_msg("background thread \"%s\" started, PID %d",
1361 ubi
->bgt_name
, task_pid_nr(current
));
1367 if (kthread_should_stop())
1370 if (try_to_freeze())
1373 spin_lock(&ubi
->wl_lock
);
1374 if (list_empty(&ubi
->works
) || ubi
->ro_mode
||
1375 !ubi
->thread_enabled
) {
1376 set_current_state(TASK_INTERRUPTIBLE
);
1377 spin_unlock(&ubi
->wl_lock
);
1381 spin_unlock(&ubi
->wl_lock
);
1385 ubi_err("%s: work failed with error code %d",
1386 ubi
->bgt_name
, err
);
1387 if (failures
++ > WL_MAX_FAILURES
) {
1389 * Too many failures, disable the thread and
1390 * switch to read-only mode.
1392 ubi_msg("%s: %d consecutive failures",
1393 ubi
->bgt_name
, WL_MAX_FAILURES
);
1403 dbg_wl("background thread \"%s\" is killed", ubi
->bgt_name
);
1408 * cancel_pending - cancel all pending works.
1409 * @ubi: UBI device description object
1411 static void cancel_pending(struct ubi_device
*ubi
)
1413 while (!list_empty(&ubi
->works
)) {
1414 struct ubi_work
*wrk
;
1416 wrk
= list_entry(ubi
->works
.next
, struct ubi_work
, list
);
1417 list_del(&wrk
->list
);
1418 wrk
->func(ubi
, wrk
, 1);
1419 ubi
->works_count
-= 1;
1420 ubi_assert(ubi
->works_count
>= 0);
1425 * ubi_wl_init_scan - initialize the wear-leveling unit using scanning
1427 * @ubi: UBI device description object
1428 * @si: scanning information
1430 * This function returns zero in case of success, and a negative error code in
1433 int ubi_wl_init_scan(struct ubi_device
*ubi
, struct ubi_scan_info
*si
)
1436 struct rb_node
*rb1
, *rb2
;
1437 struct ubi_scan_volume
*sv
;
1438 struct ubi_scan_leb
*seb
, *tmp
;
1439 struct ubi_wl_entry
*e
;
1442 ubi
->used
= ubi
->free
= ubi
->scrub
= RB_ROOT
;
1443 ubi
->prot
.pnum
= ubi
->prot
.aec
= RB_ROOT
;
1444 spin_lock_init(&ubi
->wl_lock
);
1445 mutex_init(&ubi
->move_mutex
);
1446 init_rwsem(&ubi
->work_sem
);
1447 ubi
->max_ec
= si
->max_ec
;
1448 INIT_LIST_HEAD(&ubi
->works
);
1450 sprintf(ubi
->bgt_name
, UBI_BGT_NAME_PATTERN
, ubi
->ubi_num
);
1453 ubi
->lookuptbl
= kzalloc(ubi
->peb_count
* sizeof(void *), GFP_KERNEL
);
1454 if (!ubi
->lookuptbl
)
1457 list_for_each_entry_safe(seb
, tmp
, &si
->erase
, u
.list
) {
1460 e
= kmem_cache_alloc(ubi_wl_entry_slab
, GFP_KERNEL
);
1464 e
->pnum
= seb
->pnum
;
1466 ubi
->lookuptbl
[e
->pnum
] = e
;
1467 if (schedule_erase(ubi
, e
, 0)) {
1468 kmem_cache_free(ubi_wl_entry_slab
, e
);
1473 list_for_each_entry(seb
, &si
->free
, u
.list
) {
1476 e
= kmem_cache_alloc(ubi_wl_entry_slab
, GFP_KERNEL
);
1480 e
->pnum
= seb
->pnum
;
1482 ubi_assert(e
->ec
>= 0);
1483 wl_tree_add(e
, &ubi
->free
);
1484 ubi
->lookuptbl
[e
->pnum
] = e
;
1487 list_for_each_entry(seb
, &si
->corr
, u
.list
) {
1490 e
= kmem_cache_alloc(ubi_wl_entry_slab
, GFP_KERNEL
);
1494 e
->pnum
= seb
->pnum
;
1496 ubi
->lookuptbl
[e
->pnum
] = e
;
1497 if (schedule_erase(ubi
, e
, 0)) {
1498 kmem_cache_free(ubi_wl_entry_slab
, e
);
1503 ubi_rb_for_each_entry(rb1
, sv
, &si
->volumes
, rb
) {
1504 ubi_rb_for_each_entry(rb2
, seb
, &sv
->root
, u
.rb
) {
1507 e
= kmem_cache_alloc(ubi_wl_entry_slab
, GFP_KERNEL
);
1511 e
->pnum
= seb
->pnum
;
1513 ubi
->lookuptbl
[e
->pnum
] = e
;
1515 dbg_wl("add PEB %d EC %d to the used tree",
1517 wl_tree_add(e
, &ubi
->used
);
1519 dbg_wl("add PEB %d EC %d to the scrub tree",
1521 wl_tree_add(e
, &ubi
->scrub
);
1526 if (ubi
->avail_pebs
< WL_RESERVED_PEBS
) {
1527 ubi_err("no enough physical eraseblocks (%d, need %d)",
1528 ubi
->avail_pebs
, WL_RESERVED_PEBS
);
1532 ubi
->avail_pebs
-= WL_RESERVED_PEBS
;
1533 ubi
->rsvd_pebs
+= WL_RESERVED_PEBS
;
1535 /* Schedule wear-leveling if needed */
1536 err
= ensure_wear_leveling(ubi
);
1543 cancel_pending(ubi
);
1544 tree_destroy(&ubi
->used
);
1545 tree_destroy(&ubi
->free
);
1546 tree_destroy(&ubi
->scrub
);
1547 kfree(ubi
->lookuptbl
);
1552 * protection_trees_destroy - destroy the protection RB-trees.
1553 * @ubi: UBI device description object
1555 static void protection_trees_destroy(struct ubi_device
*ubi
)
1558 struct ubi_wl_prot_entry
*pe
;
1560 rb
= ubi
->prot
.aec
.rb_node
;
1564 else if (rb
->rb_right
)
1567 pe
= rb_entry(rb
, struct ubi_wl_prot_entry
, rb_aec
);
1571 if (rb
->rb_left
== &pe
->rb_aec
)
1574 rb
->rb_right
= NULL
;
1577 kmem_cache_free(ubi_wl_entry_slab
, pe
->e
);
1584 * ubi_wl_close - close the wear-leveling unit.
1585 * @ubi: UBI device description object
1587 void ubi_wl_close(struct ubi_device
*ubi
)
1589 dbg_wl("close the UBI wear-leveling unit");
1591 cancel_pending(ubi
);
1592 protection_trees_destroy(ubi
);
1593 tree_destroy(&ubi
->used
);
1594 tree_destroy(&ubi
->free
);
1595 tree_destroy(&ubi
->scrub
);
1596 kfree(ubi
->lookuptbl
);
1599 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1602 * paranoid_check_ec - make sure that the erase counter of a physical eraseblock
1604 * @ubi: UBI device description object
1605 * @pnum: the physical eraseblock number to check
1606 * @ec: the erase counter to check
1608 * This function returns zero if the erase counter of physical eraseblock @pnum
1609 * is equivalent to @ec, %1 if not, and a negative error code if an error
1612 static int paranoid_check_ec(struct ubi_device
*ubi
, int pnum
, int ec
)
1616 struct ubi_ec_hdr
*ec_hdr
;
1618 ec_hdr
= kzalloc(ubi
->ec_hdr_alsize
, GFP_NOFS
);
1622 err
= ubi_io_read_ec_hdr(ubi
, pnum
, ec_hdr
, 0);
1623 if (err
&& err
!= UBI_IO_BITFLIPS
) {
1624 /* The header does not have to exist */
1629 read_ec
= be64_to_cpu(ec_hdr
->ec
);
1630 if (ec
!= read_ec
) {
1631 ubi_err("paranoid check failed for PEB %d", pnum
);
1632 ubi_err("read EC is %lld, should be %d", read_ec
, ec
);
1633 ubi_dbg_dump_stack();
1644 * paranoid_check_in_wl_tree - make sure that a wear-leveling entry is present
1646 * @e: the wear-leveling entry to check
1647 * @root: the root of the tree
1649 * This function returns zero if @e is in the @root RB-tree and %1 if it
1652 static int paranoid_check_in_wl_tree(struct ubi_wl_entry
*e
,
1653 struct rb_root
*root
)
1655 if (in_wl_tree(e
, root
))
1658 ubi_err("paranoid check failed for PEB %d, EC %d, RB-tree %p ",
1659 e
->pnum
, e
->ec
, root
);
1660 ubi_dbg_dump_stack();
1664 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */