6821952bcdb8d399db2aea069a1c7c4ff0dea6a5
2 * Copyright (c) International Business Machines Corp., 2006
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.
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.
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
18 * Authors: Artem Bityutskiy (Битюцкий Артём), Thomas Gleixner
22 * UBI wear-leveling sub-system.
24 * This sub-system is responsible for wear-leveling. It works in terms of
25 * physical* eraseblocks and erase counters and knows nothing about logical
26 * eraseblocks, volumes, etc. From this sub-system's perspective all physical
27 * eraseblocks are of two types - used and free. Used physical eraseblocks are
28 * those that were "get" by the 'ubi_wl_get_peb()' function, and free physical
29 * eraseblocks are those that were put by the 'ubi_wl_put_peb()' function.
31 * Physical eraseblocks returned by 'ubi_wl_get_peb()' have only erase counter
32 * header. The rest of the physical eraseblock contains only %0xFF bytes.
34 * When physical eraseblocks are returned to the WL sub-system by means of the
35 * 'ubi_wl_put_peb()' function, they are scheduled for erasure. The erasure is
36 * done asynchronously in context of the per-UBI device background thread,
37 * which is also managed by the WL sub-system.
39 * The wear-leveling is ensured by means of moving the contents of used
40 * physical eraseblocks with low erase counter to free physical eraseblocks
41 * with high erase counter.
43 * The 'ubi_wl_get_peb()' function accepts data type hints which help to pick
44 * an "optimal" physical eraseblock. For example, when it is known that the
45 * physical eraseblock will be "put" soon because it contains short-term data,
46 * the WL sub-system may pick a free physical eraseblock with low erase
47 * counter, and so forth.
49 * If the WL sub-system fails to erase a physical eraseblock, it marks it as
52 * This sub-system is also responsible for scrubbing. If a bit-flip is detected
53 * in a physical eraseblock, it has to be moved. Technically this is the same
54 * as moving it for wear-leveling reasons.
56 * As it was said, for the UBI sub-system all physical eraseblocks are either
57 * "free" or "used". Free eraseblock are kept in the @wl->free RB-tree, while
58 * used eraseblocks are kept in a set of different RB-trees: @wl->used,
59 * @wl->prot.pnum, @wl->prot.aec, and @wl->scrub.
61 * Note, in this implementation, we keep a small in-RAM object for each physical
62 * eraseblock. This is surely not a scalable solution. But it appears to be good
63 * enough for moderately large flashes and it is simple. In future, one may
64 * re-work this sub-system and make it more scalable.
66 * At the moment this sub-system does not utilize the sequence number, which
67 * was introduced relatively recently. But it would be wise to do this because
68 * the sequence number of a logical eraseblock characterizes how old is it. For
69 * example, when we move a PEB with low erase counter, and we need to pick the
70 * target PEB, we pick a PEB with the highest EC if our PEB is "old" and we
71 * pick target PEB with an average EC if our PEB is not very "old". This is a
72 * room for future re-works of the WL sub-system.
74 * Note: the stuff with protection trees looks too complex and is difficult to
75 * understand. Should be fixed.
78 #include <linux/slab.h>
79 #include <linux/crc32.h>
80 #include <linux/freezer.h>
81 #include <linux/kthread.h>
84 /* Number of physical eraseblocks reserved for wear-leveling purposes */
85 #define WL_RESERVED_PEBS 1
88 * How many erase cycles are short term, unknown, and long term physical
89 * eraseblocks protected.
91 #define ST_PROTECTION 16
92 #define U_PROTECTION 10
93 #define LT_PROTECTION 4
96 * Maximum difference between two erase counters. If this threshold is
97 * exceeded, the WL sub-system starts moving data from used physical
98 * eraseblocks with low erase counter to free physical eraseblocks with high
101 #define UBI_WL_THRESHOLD CONFIG_MTD_UBI_WL_THRESHOLD
104 * When a physical eraseblock is moved, the WL sub-system has to pick the target
105 * physical eraseblock to move to. The simplest way would be just to pick the
106 * one with the highest erase counter. But in certain workloads this could lead
107 * to an unlimited wear of one or few physical eraseblock. Indeed, imagine a
108 * situation when the picked physical eraseblock is constantly erased after the
109 * data is written to it. So, we have a constant which limits the highest erase
110 * counter of the free physical eraseblock to pick. Namely, the WL sub-system
111 * does not pick eraseblocks with erase counter greater then the lowest erase
112 * counter plus %WL_FREE_MAX_DIFF.
114 #define WL_FREE_MAX_DIFF (2*UBI_WL_THRESHOLD)
117 * Maximum number of consecutive background thread failures which is enough to
118 * switch to read-only mode.
120 #define WL_MAX_FAILURES 32
123 * struct ubi_wl_prot_entry - PEB protection entry.
124 * @rb_pnum: link in the @wl->prot.pnum RB-tree
125 * @rb_aec: link in the @wl->prot.aec RB-tree
126 * @abs_ec: the absolute erase counter value when the protection ends
127 * @e: the wear-leveling entry of the physical eraseblock under protection
129 * When the WL sub-system returns a physical eraseblock, the physical
130 * eraseblock is protected from being moved for some "time". For this reason,
131 * the physical eraseblock is not directly moved from the @wl->free tree to the
132 * @wl->used tree. There is one more tree in between where this physical
133 * eraseblock is temporarily stored (@wl->prot).
135 * All this protection stuff is needed because:
136 * o we don't want to move physical eraseblocks just after we have given them
137 * to the user; instead, we first want to let users fill them up with data;
139 * o there is a chance that the user will put the physical eraseblock very
140 * soon, so it makes sense not to move it for some time, but wait; this is
141 * especially important in case of "short term" physical eraseblocks.
143 * Physical eraseblocks stay protected only for limited time. But the "time" is
144 * measured in erase cycles in this case. This is implemented with help of the
145 * absolute erase counter (@wl->abs_ec). When it reaches certain value, the
146 * physical eraseblocks are moved from the protection trees (@wl->prot.*) to
147 * the @wl->used tree.
149 * Protected physical eraseblocks are searched by physical eraseblock number
150 * (when they are put) and by the absolute erase counter (to check if it is
151 * time to move them to the @wl->used tree). So there are actually 2 RB-trees
152 * storing the protected physical eraseblocks: @wl->prot.pnum and
153 * @wl->prot.aec. They are referred to as the "protection" trees. The
154 * first one is indexed by the physical eraseblock number. The second one is
155 * indexed by the absolute erase counter. Both trees store
156 * &struct ubi_wl_prot_entry objects.
158 * Each physical eraseblock has 2 main states: free and used. The former state
159 * corresponds to the @wl->free tree. The latter state is split up on several
161 * o the WL movement is allowed (@wl->used tree);
162 * o the WL movement is temporarily prohibited (@wl->prot.pnum and
163 * @wl->prot.aec trees);
164 * o scrubbing is needed (@wl->scrub tree).
166 * Depending on the sub-state, wear-leveling entries of the used physical
167 * eraseblocks may be kept in one of those trees.
169 struct ubi_wl_prot_entry
{
170 struct rb_node rb_pnum
;
171 struct rb_node rb_aec
;
172 unsigned long long abs_ec
;
173 struct ubi_wl_entry
*e
;
177 * struct ubi_work - UBI work description data structure.
178 * @list: a link in the list of pending works
179 * @func: worker function
180 * @priv: private data of the worker function
181 * @e: physical eraseblock to erase
182 * @torture: if the physical eraseblock has to be tortured
184 * The @func pointer points to the worker function. If the @cancel argument is
185 * not zero, the worker has to free the resources and exit immediately. The
186 * worker has to return zero in case of success and a negative error code in
190 struct list_head list
;
191 int (*func
)(struct ubi_device
*ubi
, struct ubi_work
*wrk
, int cancel
);
192 /* The below fields are only relevant to erasure works */
193 struct ubi_wl_entry
*e
;
197 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
198 static int paranoid_check_ec(struct ubi_device
*ubi
, int pnum
, int ec
);
199 static int paranoid_check_in_wl_tree(struct ubi_wl_entry
*e
,
200 struct rb_root
*root
);
202 #define paranoid_check_ec(ubi, pnum, ec) 0
203 #define paranoid_check_in_wl_tree(e, root)
207 * wl_tree_add - add a wear-leveling entry to a WL RB-tree.
208 * @e: the wear-leveling entry to add
209 * @root: the root of the tree
211 * Note, we use (erase counter, physical eraseblock number) pairs as keys in
212 * the @ubi->used and @ubi->free RB-trees.
214 static void wl_tree_add(struct ubi_wl_entry
*e
, struct rb_root
*root
)
216 struct rb_node
**p
, *parent
= NULL
;
220 struct ubi_wl_entry
*e1
;
223 e1
= rb_entry(parent
, struct ubi_wl_entry
, rb
);
227 else if (e
->ec
> e1
->ec
)
230 ubi_assert(e
->pnum
!= e1
->pnum
);
231 if (e
->pnum
< e1
->pnum
)
238 rb_link_node(&e
->rb
, parent
, p
);
239 rb_insert_color(&e
->rb
, root
);
243 * do_work - do one pending work.
244 * @ubi: UBI device description object
246 * This function returns zero in case of success and a negative error code in
249 static int do_work(struct ubi_device
*ubi
)
252 struct ubi_work
*wrk
;
257 * @ubi->work_sem is used to synchronize with the workers. Workers take
258 * it in read mode, so many of them may be doing works at a time. But
259 * the queue flush code has to be sure the whole queue of works is
260 * done, and it takes the mutex in write mode.
262 down_read(&ubi
->work_sem
);
263 spin_lock(&ubi
->wl_lock
);
264 if (list_empty(&ubi
->works
)) {
265 spin_unlock(&ubi
->wl_lock
);
266 up_read(&ubi
->work_sem
);
270 wrk
= list_entry(ubi
->works
.next
, struct ubi_work
, list
);
271 list_del(&wrk
->list
);
272 ubi
->works_count
-= 1;
273 ubi_assert(ubi
->works_count
>= 0);
274 spin_unlock(&ubi
->wl_lock
);
277 * Call the worker function. Do not touch the work structure
278 * after this call as it will have been freed or reused by that
279 * time by the worker function.
281 err
= wrk
->func(ubi
, wrk
, 0);
283 ubi_err("work failed with error code %d", err
);
284 up_read(&ubi
->work_sem
);
290 * produce_free_peb - produce a free physical eraseblock.
291 * @ubi: UBI device description object
293 * This function tries to make a free PEB by means of synchronous execution of
294 * pending works. This may be needed if, for example the background thread is
295 * disabled. Returns zero in case of success and a negative error code in case
298 static int produce_free_peb(struct ubi_device
*ubi
)
302 spin_lock(&ubi
->wl_lock
);
303 while (!ubi
->free
.rb_node
) {
304 spin_unlock(&ubi
->wl_lock
);
306 dbg_wl("do one work synchronously");
311 spin_lock(&ubi
->wl_lock
);
313 spin_unlock(&ubi
->wl_lock
);
319 * in_wl_tree - check if wear-leveling entry is present in a WL RB-tree.
320 * @e: the wear-leveling entry to check
321 * @root: the root of the tree
323 * This function returns non-zero if @e is in the @root RB-tree and zero if it
326 static int in_wl_tree(struct ubi_wl_entry
*e
, struct rb_root
*root
)
332 struct ubi_wl_entry
*e1
;
334 e1
= rb_entry(p
, struct ubi_wl_entry
, rb
);
336 if (e
->pnum
== e1
->pnum
) {
343 else if (e
->ec
> e1
->ec
)
346 ubi_assert(e
->pnum
!= e1
->pnum
);
347 if (e
->pnum
< e1
->pnum
)
358 * prot_tree_add - add physical eraseblock to protection trees.
359 * @ubi: UBI device description object
360 * @e: the physical eraseblock to add
361 * @pe: protection entry object to use
362 * @abs_ec: absolute erase counter value when this physical eraseblock has
363 * to be removed from the protection trees.
365 * @wl->lock has to be locked.
367 static void prot_tree_add(struct ubi_device
*ubi
, struct ubi_wl_entry
*e
,
368 struct ubi_wl_prot_entry
*pe
, int abs_ec
)
370 struct rb_node
**p
, *parent
= NULL
;
371 struct ubi_wl_prot_entry
*pe1
;
374 pe
->abs_ec
= ubi
->abs_ec
+ abs_ec
;
376 p
= &ubi
->prot
.pnum
.rb_node
;
379 pe1
= rb_entry(parent
, struct ubi_wl_prot_entry
, rb_pnum
);
381 if (e
->pnum
< pe1
->e
->pnum
)
386 rb_link_node(&pe
->rb_pnum
, parent
, p
);
387 rb_insert_color(&pe
->rb_pnum
, &ubi
->prot
.pnum
);
389 p
= &ubi
->prot
.aec
.rb_node
;
393 pe1
= rb_entry(parent
, struct ubi_wl_prot_entry
, rb_aec
);
395 if (pe
->abs_ec
< pe1
->abs_ec
)
400 rb_link_node(&pe
->rb_aec
, parent
, p
);
401 rb_insert_color(&pe
->rb_aec
, &ubi
->prot
.aec
);
405 * find_wl_entry - find wear-leveling entry closest to certain erase counter.
406 * @root: the RB-tree where to look for
407 * @max: highest possible erase counter
409 * This function looks for a wear leveling entry with erase counter closest to
410 * @max and less then @max.
412 static struct ubi_wl_entry
*find_wl_entry(struct rb_root
*root
, int max
)
415 struct ubi_wl_entry
*e
;
417 e
= rb_entry(rb_first(root
), struct ubi_wl_entry
, rb
);
422 struct ubi_wl_entry
*e1
;
424 e1
= rb_entry(p
, struct ubi_wl_entry
, rb
);
437 * ubi_wl_get_peb - get a physical eraseblock.
438 * @ubi: UBI device description object
439 * @dtype: type of data which will be stored in this physical eraseblock
441 * This function returns a physical eraseblock in case of success and a
442 * negative error code in case of failure. Might sleep.
444 int ubi_wl_get_peb(struct ubi_device
*ubi
, int dtype
)
446 int err
, protect
, medium_ec
;
447 struct ubi_wl_entry
*e
, *first
, *last
;
448 struct ubi_wl_prot_entry
*pe
;
450 ubi_assert(dtype
== UBI_LONGTERM
|| dtype
== UBI_SHORTTERM
||
451 dtype
== UBI_UNKNOWN
);
453 pe
= kmalloc(sizeof(struct ubi_wl_prot_entry
), GFP_NOFS
);
458 spin_lock(&ubi
->wl_lock
);
459 if (!ubi
->free
.rb_node
) {
460 if (ubi
->works_count
== 0) {
461 ubi_assert(list_empty(&ubi
->works
));
462 ubi_err("no free eraseblocks");
463 spin_unlock(&ubi
->wl_lock
);
467 spin_unlock(&ubi
->wl_lock
);
469 err
= produce_free_peb(ubi
);
480 * For long term data we pick a physical eraseblock
481 * with high erase counter. But the highest erase
482 * counter we can pick is bounded by the the lowest
483 * erase counter plus %WL_FREE_MAX_DIFF.
485 e
= find_wl_entry(&ubi
->free
, WL_FREE_MAX_DIFF
);
486 protect
= LT_PROTECTION
;
490 * For unknown data we pick a physical eraseblock with
491 * medium erase counter. But we by no means can pick a
492 * physical eraseblock with erase counter greater or
493 * equivalent than the lowest erase counter plus
496 first
= rb_entry(rb_first(&ubi
->free
),
497 struct ubi_wl_entry
, rb
);
498 last
= rb_entry(rb_last(&ubi
->free
),
499 struct ubi_wl_entry
, rb
);
501 if (last
->ec
- first
->ec
< WL_FREE_MAX_DIFF
)
502 e
= rb_entry(ubi
->free
.rb_node
,
503 struct ubi_wl_entry
, rb
);
505 medium_ec
= (first
->ec
+ WL_FREE_MAX_DIFF
)/2;
506 e
= find_wl_entry(&ubi
->free
, medium_ec
);
508 protect
= U_PROTECTION
;
512 * For short term data we pick a physical eraseblock
513 * with the lowest erase counter as we expect it will
516 e
= rb_entry(rb_first(&ubi
->free
),
517 struct ubi_wl_entry
, rb
);
518 protect
= ST_PROTECTION
;
527 * Move the physical eraseblock to the protection trees where it will
528 * be protected from being moved for some time.
530 paranoid_check_in_wl_tree(e
, &ubi
->free
);
531 rb_erase(&e
->rb
, &ubi
->free
);
532 prot_tree_add(ubi
, e
, pe
, protect
);
534 dbg_wl("PEB %d EC %d, protection %d", e
->pnum
, e
->ec
, protect
);
535 spin_unlock(&ubi
->wl_lock
);
541 * prot_tree_del - remove a physical eraseblock from the protection trees
542 * @ubi: UBI device description object
543 * @pnum: the physical eraseblock to remove
545 * This function returns PEB @pnum from the protection trees and returns zero
546 * in case of success and %-ENODEV if the PEB was not found in the protection
549 static int prot_tree_del(struct ubi_device
*ubi
, int pnum
)
552 struct ubi_wl_prot_entry
*pe
= NULL
;
554 p
= ubi
->prot
.pnum
.rb_node
;
557 pe
= rb_entry(p
, struct ubi_wl_prot_entry
, rb_pnum
);
559 if (pnum
== pe
->e
->pnum
)
562 if (pnum
< pe
->e
->pnum
)
571 ubi_assert(pe
->e
->pnum
== pnum
);
572 rb_erase(&pe
->rb_aec
, &ubi
->prot
.aec
);
573 rb_erase(&pe
->rb_pnum
, &ubi
->prot
.pnum
);
579 * sync_erase - synchronously erase a physical eraseblock.
580 * @ubi: UBI device description object
581 * @e: the the physical eraseblock to erase
582 * @torture: if the physical eraseblock has to be tortured
584 * This function returns zero in case of success and a negative error code in
587 static int sync_erase(struct ubi_device
*ubi
, struct ubi_wl_entry
*e
, int torture
)
590 struct ubi_ec_hdr
*ec_hdr
;
591 unsigned long long ec
= e
->ec
;
593 dbg_wl("erase PEB %d, old EC %llu", e
->pnum
, ec
);
595 err
= paranoid_check_ec(ubi
, e
->pnum
, e
->ec
);
599 ec_hdr
= kzalloc(ubi
->ec_hdr_alsize
, GFP_NOFS
);
603 err
= ubi_io_sync_erase(ubi
, e
->pnum
, torture
);
608 if (ec
> UBI_MAX_ERASECOUNTER
) {
610 * Erase counter overflow. Upgrade UBI and use 64-bit
611 * erase counters internally.
613 ubi_err("erase counter overflow at PEB %d, EC %llu",
619 dbg_wl("erased PEB %d, new EC %llu", e
->pnum
, ec
);
621 ec_hdr
->ec
= cpu_to_be64(ec
);
623 err
= ubi_io_write_ec_hdr(ubi
, e
->pnum
, ec_hdr
);
628 spin_lock(&ubi
->wl_lock
);
629 if (e
->ec
> ubi
->max_ec
)
631 spin_unlock(&ubi
->wl_lock
);
639 * check_protection_over - check if it is time to stop protecting some
640 * physical eraseblocks.
641 * @ubi: UBI device description object
643 * This function is called after each erase operation, when the absolute erase
644 * counter is incremented, to check if some physical eraseblock have not to be
645 * protected any longer. These physical eraseblocks are moved from the
646 * protection trees to the used tree.
648 static void check_protection_over(struct ubi_device
*ubi
)
650 struct ubi_wl_prot_entry
*pe
;
653 * There may be several protected physical eraseblock to remove,
657 spin_lock(&ubi
->wl_lock
);
658 if (!ubi
->prot
.aec
.rb_node
) {
659 spin_unlock(&ubi
->wl_lock
);
663 pe
= rb_entry(rb_first(&ubi
->prot
.aec
),
664 struct ubi_wl_prot_entry
, rb_aec
);
666 if (pe
->abs_ec
> ubi
->abs_ec
) {
667 spin_unlock(&ubi
->wl_lock
);
671 dbg_wl("PEB %d protection over, abs_ec %llu, PEB abs_ec %llu",
672 pe
->e
->pnum
, ubi
->abs_ec
, pe
->abs_ec
);
673 rb_erase(&pe
->rb_aec
, &ubi
->prot
.aec
);
674 rb_erase(&pe
->rb_pnum
, &ubi
->prot
.pnum
);
675 wl_tree_add(pe
->e
, &ubi
->used
);
676 spin_unlock(&ubi
->wl_lock
);
684 * schedule_ubi_work - schedule a work.
685 * @ubi: UBI device description object
686 * @wrk: the work to schedule
688 * This function enqueues a work defined by @wrk to the tail of the pending
691 static void schedule_ubi_work(struct ubi_device
*ubi
, struct ubi_work
*wrk
)
693 spin_lock(&ubi
->wl_lock
);
694 list_add_tail(&wrk
->list
, &ubi
->works
);
695 ubi_assert(ubi
->works_count
>= 0);
696 ubi
->works_count
+= 1;
697 if (ubi
->thread_enabled
)
698 wake_up_process(ubi
->bgt_thread
);
699 spin_unlock(&ubi
->wl_lock
);
702 static int erase_worker(struct ubi_device
*ubi
, struct ubi_work
*wl_wrk
,
706 * schedule_erase - schedule an erase work.
707 * @ubi: UBI device description object
708 * @e: the WL entry of the physical eraseblock to erase
709 * @torture: if the physical eraseblock has to be tortured
711 * This function returns zero in case of success and a %-ENOMEM in case of
714 static int schedule_erase(struct ubi_device
*ubi
, struct ubi_wl_entry
*e
,
717 struct ubi_work
*wl_wrk
;
719 dbg_wl("schedule erasure of PEB %d, EC %d, torture %d",
720 e
->pnum
, e
->ec
, torture
);
722 wl_wrk
= kmalloc(sizeof(struct ubi_work
), GFP_NOFS
);
726 wl_wrk
->func
= &erase_worker
;
728 wl_wrk
->torture
= torture
;
730 schedule_ubi_work(ubi
, wl_wrk
);
735 * wear_leveling_worker - wear-leveling worker function.
736 * @ubi: UBI device description object
737 * @wrk: the work object
738 * @cancel: non-zero if the worker has to free memory and exit
740 * This function copies a more worn out physical eraseblock to a less worn out
741 * one. Returns zero in case of success and a negative error code in case of
744 static int wear_leveling_worker(struct ubi_device
*ubi
, struct ubi_work
*wrk
,
747 int err
, put
= 0, scrubbing
= 0, protect
= 0;
748 struct ubi_wl_prot_entry
*uninitialized_var(pe
);
749 struct ubi_wl_entry
*e1
, *e2
;
750 struct ubi_vid_hdr
*vid_hdr
;
757 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
761 mutex_lock(&ubi
->move_mutex
);
762 spin_lock(&ubi
->wl_lock
);
763 ubi_assert(!ubi
->move_from
&& !ubi
->move_to
);
764 ubi_assert(!ubi
->move_to_put
);
766 if (!ubi
->free
.rb_node
||
767 (!ubi
->used
.rb_node
&& !ubi
->scrub
.rb_node
)) {
769 * No free physical eraseblocks? Well, they must be waiting in
770 * the queue to be erased. Cancel movement - it will be
771 * triggered again when a free physical eraseblock appears.
773 * No used physical eraseblocks? They must be temporarily
774 * protected from being moved. They will be moved to the
775 * @ubi->used tree later and the wear-leveling will be
778 dbg_wl("cancel WL, a list is empty: free %d, used %d",
779 !ubi
->free
.rb_node
, !ubi
->used
.rb_node
);
783 if (!ubi
->scrub
.rb_node
) {
785 * Now pick the least worn-out used physical eraseblock and a
786 * highly worn-out free physical eraseblock. If the erase
787 * counters differ much enough, start wear-leveling.
789 e1
= rb_entry(rb_first(&ubi
->used
), struct ubi_wl_entry
, rb
);
790 e2
= find_wl_entry(&ubi
->free
, WL_FREE_MAX_DIFF
);
792 if (!(e2
->ec
- e1
->ec
>= UBI_WL_THRESHOLD
)) {
793 dbg_wl("no WL needed: min used EC %d, max free EC %d",
797 paranoid_check_in_wl_tree(e1
, &ubi
->used
);
798 rb_erase(&e1
->rb
, &ubi
->used
);
799 dbg_wl("move PEB %d EC %d to PEB %d EC %d",
800 e1
->pnum
, e1
->ec
, e2
->pnum
, e2
->ec
);
802 /* Perform scrubbing */
804 e1
= rb_entry(rb_first(&ubi
->scrub
), struct ubi_wl_entry
, rb
);
805 e2
= find_wl_entry(&ubi
->free
, WL_FREE_MAX_DIFF
);
806 paranoid_check_in_wl_tree(e1
, &ubi
->scrub
);
807 rb_erase(&e1
->rb
, &ubi
->scrub
);
808 dbg_wl("scrub PEB %d to PEB %d", e1
->pnum
, e2
->pnum
);
811 paranoid_check_in_wl_tree(e2
, &ubi
->free
);
812 rb_erase(&e2
->rb
, &ubi
->free
);
815 spin_unlock(&ubi
->wl_lock
);
818 * Now we are going to copy physical eraseblock @e1->pnum to @e2->pnum.
819 * We so far do not know which logical eraseblock our physical
820 * eraseblock (@e1) belongs to. We have to read the volume identifier
823 * Note, we are protected from this PEB being unmapped and erased. The
824 * 'ubi_wl_put_peb()' would wait for moving to be finished if the PEB
825 * which is being moved was unmapped.
828 err
= ubi_io_read_vid_hdr(ubi
, e1
->pnum
, vid_hdr
, 0);
829 if (err
&& err
!= UBI_IO_BITFLIPS
) {
830 if (err
== UBI_IO_PEB_FREE
) {
832 * We are trying to move PEB without a VID header. UBI
833 * always write VID headers shortly after the PEB was
834 * given, so we have a situation when it did not have
835 * chance to write it down because it was preempted.
836 * Just re-schedule the work, so that next time it will
837 * likely have the VID header in place.
839 dbg_wl("PEB %d has no VID header", e1
->pnum
);
843 ubi_err("error %d while reading VID header from PEB %d",
850 err
= ubi_eba_copy_leb(ubi
, e1
->pnum
, e2
->pnum
, vid_hdr
);
859 * For some reason the LEB was not moved - it might be because
860 * the volume is being deleted. We should prevent this PEB from
861 * being selected for wear-levelling movement for some "time",
862 * so put it to the protection tree.
865 dbg_wl("cancelled moving PEB %d", e1
->pnum
);
866 pe
= kmalloc(sizeof(struct ubi_wl_prot_entry
), GFP_NOFS
);
875 ubi_free_vid_hdr(ubi
, vid_hdr
);
876 if (scrubbing
&& !protect
)
877 ubi_msg("scrubbed PEB %d, data moved to PEB %d",
880 spin_lock(&ubi
->wl_lock
);
882 prot_tree_add(ubi
, e1
, pe
, protect
);
883 if (!ubi
->move_to_put
)
884 wl_tree_add(e2
, &ubi
->used
);
887 ubi
->move_from
= ubi
->move_to
= NULL
;
888 ubi
->move_to_put
= ubi
->wl_scheduled
= 0;
889 spin_unlock(&ubi
->wl_lock
);
893 * Well, the target PEB was put meanwhile, schedule it for
896 dbg_wl("PEB %d was put meanwhile, erase", e2
->pnum
);
897 err
= schedule_erase(ubi
, e2
, 0);
903 err
= schedule_erase(ubi
, e1
, 0);
910 mutex_unlock(&ubi
->move_mutex
);
914 * For some reasons the LEB was not moved, might be an error, might be
915 * something else. @e1 was not changed, so return it back. @e2 might
916 * be changed, schedule it for erasure.
919 ubi_free_vid_hdr(ubi
, vid_hdr
);
920 spin_lock(&ubi
->wl_lock
);
922 wl_tree_add(e1
, &ubi
->scrub
);
924 wl_tree_add(e1
, &ubi
->used
);
925 ubi
->move_from
= ubi
->move_to
= NULL
;
926 ubi
->move_to_put
= ubi
->wl_scheduled
= 0;
927 spin_unlock(&ubi
->wl_lock
);
929 err
= schedule_erase(ubi
, e2
, 0);
933 mutex_unlock(&ubi
->move_mutex
);
937 ubi_err("error %d while moving PEB %d to PEB %d",
938 err
, e1
->pnum
, e2
->pnum
);
940 ubi_free_vid_hdr(ubi
, vid_hdr
);
941 spin_lock(&ubi
->wl_lock
);
942 ubi
->move_from
= ubi
->move_to
= NULL
;
943 ubi
->move_to_put
= ubi
->wl_scheduled
= 0;
944 spin_unlock(&ubi
->wl_lock
);
946 kmem_cache_free(ubi_wl_entry_slab
, e1
);
947 kmem_cache_free(ubi_wl_entry_slab
, e2
);
950 mutex_unlock(&ubi
->move_mutex
);
954 ubi
->wl_scheduled
= 0;
955 spin_unlock(&ubi
->wl_lock
);
956 mutex_unlock(&ubi
->move_mutex
);
957 ubi_free_vid_hdr(ubi
, vid_hdr
);
962 * ensure_wear_leveling - schedule wear-leveling if it is needed.
963 * @ubi: UBI device description object
965 * This function checks if it is time to start wear-leveling and schedules it
966 * if yes. This function returns zero in case of success and a negative error
967 * code in case of failure.
969 static int ensure_wear_leveling(struct ubi_device
*ubi
)
972 struct ubi_wl_entry
*e1
;
973 struct ubi_wl_entry
*e2
;
974 struct ubi_work
*wrk
;
976 spin_lock(&ubi
->wl_lock
);
977 if (ubi
->wl_scheduled
)
978 /* Wear-leveling is already in the work queue */
982 * If the ubi->scrub tree is not empty, scrubbing is needed, and the
983 * the WL worker has to be scheduled anyway.
985 if (!ubi
->scrub
.rb_node
) {
986 if (!ubi
->used
.rb_node
|| !ubi
->free
.rb_node
)
987 /* No physical eraseblocks - no deal */
991 * We schedule wear-leveling only if the difference between the
992 * lowest erase counter of used physical eraseblocks and a high
993 * erase counter of free physical eraseblocks is greater then
996 e1
= rb_entry(rb_first(&ubi
->used
), struct ubi_wl_entry
, rb
);
997 e2
= find_wl_entry(&ubi
->free
, WL_FREE_MAX_DIFF
);
999 if (!(e2
->ec
- e1
->ec
>= UBI_WL_THRESHOLD
))
1001 dbg_wl("schedule wear-leveling");
1003 dbg_wl("schedule scrubbing");
1005 ubi
->wl_scheduled
= 1;
1006 spin_unlock(&ubi
->wl_lock
);
1008 wrk
= kmalloc(sizeof(struct ubi_work
), GFP_NOFS
);
1014 wrk
->func
= &wear_leveling_worker
;
1015 schedule_ubi_work(ubi
, wrk
);
1019 spin_lock(&ubi
->wl_lock
);
1020 ubi
->wl_scheduled
= 0;
1022 spin_unlock(&ubi
->wl_lock
);
1027 * erase_worker - physical eraseblock erase worker function.
1028 * @ubi: UBI device description object
1029 * @wl_wrk: the work object
1030 * @cancel: non-zero if the worker has to free memory and exit
1032 * This function erases a physical eraseblock and perform torture testing if
1033 * needed. It also takes care about marking the physical eraseblock bad if
1034 * needed. Returns zero in case of success and a negative error code in case of
1037 static int erase_worker(struct ubi_device
*ubi
, struct ubi_work
*wl_wrk
,
1040 struct ubi_wl_entry
*e
= wl_wrk
->e
;
1041 int pnum
= e
->pnum
, err
, need
;
1044 dbg_wl("cancel erasure of PEB %d EC %d", pnum
, e
->ec
);
1046 kmem_cache_free(ubi_wl_entry_slab
, e
);
1050 dbg_wl("erase PEB %d EC %d", pnum
, e
->ec
);
1052 err
= sync_erase(ubi
, e
, wl_wrk
->torture
);
1054 /* Fine, we've erased it successfully */
1057 spin_lock(&ubi
->wl_lock
);
1059 wl_tree_add(e
, &ubi
->free
);
1060 spin_unlock(&ubi
->wl_lock
);
1063 * One more erase operation has happened, take care about protected
1064 * physical eraseblocks.
1066 check_protection_over(ubi
);
1068 /* And take care about wear-leveling */
1069 err
= ensure_wear_leveling(ubi
);
1073 ubi_err("failed to erase PEB %d, error %d", pnum
, err
);
1075 kmem_cache_free(ubi_wl_entry_slab
, e
);
1077 if (err
== -EINTR
|| err
== -ENOMEM
|| err
== -EAGAIN
||
1081 /* Re-schedule the LEB for erasure */
1082 err1
= schedule_erase(ubi
, e
, 0);
1088 } else if (err
!= -EIO
) {
1090 * If this is not %-EIO, we have no idea what to do. Scheduling
1091 * this physical eraseblock for erasure again would cause
1092 * errors again and again. Well, lets switch to RO mode.
1097 /* It is %-EIO, the PEB went bad */
1099 if (!ubi
->bad_allowed
) {
1100 ubi_err("bad physical eraseblock %d detected", pnum
);
1104 spin_lock(&ubi
->volumes_lock
);
1105 need
= ubi
->beb_rsvd_level
- ubi
->beb_rsvd_pebs
+ 1;
1107 need
= ubi
->avail_pebs
>= need
? need
: ubi
->avail_pebs
;
1108 ubi
->avail_pebs
-= need
;
1109 ubi
->rsvd_pebs
+= need
;
1110 ubi
->beb_rsvd_pebs
+= need
;
1112 ubi_msg("reserve more %d PEBs", need
);
1115 if (ubi
->beb_rsvd_pebs
== 0) {
1116 spin_unlock(&ubi
->volumes_lock
);
1117 ubi_err("no reserved physical eraseblocks");
1121 spin_unlock(&ubi
->volumes_lock
);
1122 ubi_msg("mark PEB %d as bad", pnum
);
1124 err
= ubi_io_mark_bad(ubi
, pnum
);
1128 spin_lock(&ubi
->volumes_lock
);
1129 ubi
->beb_rsvd_pebs
-= 1;
1130 ubi
->bad_peb_count
+= 1;
1131 ubi
->good_peb_count
-= 1;
1132 ubi_calculate_reserved(ubi
);
1133 if (ubi
->beb_rsvd_pebs
== 0)
1134 ubi_warn("last PEB from the reserved pool was used");
1135 spin_unlock(&ubi
->volumes_lock
);
1145 * ubi_wl_put_peb - return a PEB to the wear-leveling sub-system.
1146 * @ubi: UBI device description object
1147 * @pnum: physical eraseblock to return
1148 * @torture: if this physical eraseblock has to be tortured
1150 * This function is called to return physical eraseblock @pnum to the pool of
1151 * free physical eraseblocks. The @torture flag has to be set if an I/O error
1152 * occurred to this @pnum and it has to be tested. This function returns zero
1153 * in case of success, and a negative error code in case of failure.
1155 int ubi_wl_put_peb(struct ubi_device
*ubi
, int pnum
, int torture
)
1158 struct ubi_wl_entry
*e
;
1160 dbg_wl("PEB %d", pnum
);
1161 ubi_assert(pnum
>= 0);
1162 ubi_assert(pnum
< ubi
->peb_count
);
1165 spin_lock(&ubi
->wl_lock
);
1166 e
= ubi
->lookuptbl
[pnum
];
1167 if (e
== ubi
->move_from
) {
1169 * User is putting the physical eraseblock which was selected to
1170 * be moved. It will be scheduled for erasure in the
1171 * wear-leveling worker.
1173 dbg_wl("PEB %d is being moved, wait", pnum
);
1174 spin_unlock(&ubi
->wl_lock
);
1176 /* Wait for the WL worker by taking the @ubi->move_mutex */
1177 mutex_lock(&ubi
->move_mutex
);
1178 mutex_unlock(&ubi
->move_mutex
);
1180 } else if (e
== ubi
->move_to
) {
1182 * User is putting the physical eraseblock which was selected
1183 * as the target the data is moved to. It may happen if the EBA
1184 * sub-system already re-mapped the LEB in 'ubi_eba_copy_leb()'
1185 * but the WL sub-system has not put the PEB to the "used" tree
1186 * yet, but it is about to do this. So we just set a flag which
1187 * will tell the WL worker that the PEB is not needed anymore
1188 * and should be scheduled for erasure.
1190 dbg_wl("PEB %d is the target of data moving", pnum
);
1191 ubi_assert(!ubi
->move_to_put
);
1192 ubi
->move_to_put
= 1;
1193 spin_unlock(&ubi
->wl_lock
);
1196 if (in_wl_tree(e
, &ubi
->used
)) {
1197 paranoid_check_in_wl_tree(e
, &ubi
->used
);
1198 rb_erase(&e
->rb
, &ubi
->used
);
1199 } else if (in_wl_tree(e
, &ubi
->scrub
)) {
1200 paranoid_check_in_wl_tree(e
, &ubi
->scrub
);
1201 rb_erase(&e
->rb
, &ubi
->scrub
);
1203 err
= prot_tree_del(ubi
, e
->pnum
);
1205 ubi_err("PEB %d not found", pnum
);
1207 spin_unlock(&ubi
->wl_lock
);
1212 spin_unlock(&ubi
->wl_lock
);
1214 err
= schedule_erase(ubi
, e
, torture
);
1216 spin_lock(&ubi
->wl_lock
);
1217 wl_tree_add(e
, &ubi
->used
);
1218 spin_unlock(&ubi
->wl_lock
);
1225 * ubi_wl_scrub_peb - schedule a physical eraseblock for scrubbing.
1226 * @ubi: UBI device description object
1227 * @pnum: the physical eraseblock to schedule
1229 * If a bit-flip in a physical eraseblock is detected, this physical eraseblock
1230 * needs scrubbing. This function schedules a physical eraseblock for
1231 * scrubbing which is done in background. This function returns zero in case of
1232 * success and a negative error code in case of failure.
1234 int ubi_wl_scrub_peb(struct ubi_device
*ubi
, int pnum
)
1236 struct ubi_wl_entry
*e
;
1238 dbg_msg("schedule PEB %d for scrubbing", pnum
);
1241 spin_lock(&ubi
->wl_lock
);
1242 e
= ubi
->lookuptbl
[pnum
];
1243 if (e
== ubi
->move_from
|| in_wl_tree(e
, &ubi
->scrub
)) {
1244 spin_unlock(&ubi
->wl_lock
);
1248 if (e
== ubi
->move_to
) {
1250 * This physical eraseblock was used to move data to. The data
1251 * was moved but the PEB was not yet inserted to the proper
1252 * tree. We should just wait a little and let the WL worker
1255 spin_unlock(&ubi
->wl_lock
);
1256 dbg_wl("the PEB %d is not in proper tree, retry", pnum
);
1261 if (in_wl_tree(e
, &ubi
->used
)) {
1262 paranoid_check_in_wl_tree(e
, &ubi
->used
);
1263 rb_erase(&e
->rb
, &ubi
->used
);
1267 err
= prot_tree_del(ubi
, e
->pnum
);
1269 ubi_err("PEB %d not found", pnum
);
1271 spin_unlock(&ubi
->wl_lock
);
1276 wl_tree_add(e
, &ubi
->scrub
);
1277 spin_unlock(&ubi
->wl_lock
);
1280 * Technically scrubbing is the same as wear-leveling, so it is done
1283 return ensure_wear_leveling(ubi
);
1287 * ubi_wl_flush - flush all pending works.
1288 * @ubi: UBI device description object
1290 * This function returns zero in case of success and a negative error code in
1293 int ubi_wl_flush(struct ubi_device
*ubi
)
1298 * Erase while the pending works queue is not empty, but not more then
1299 * the number of currently pending works.
1301 dbg_wl("flush (%d pending works)", ubi
->works_count
);
1302 while (ubi
->works_count
) {
1309 * Make sure all the works which have been done in parallel are
1312 down_write(&ubi
->work_sem
);
1313 up_write(&ubi
->work_sem
);
1316 * And in case last was the WL worker and it cancelled the LEB
1317 * movement, flush again.
1319 while (ubi
->works_count
) {
1320 dbg_wl("flush more (%d pending works)", ubi
->works_count
);
1330 * tree_destroy - destroy an RB-tree.
1331 * @root: the root of the tree to destroy
1333 static void tree_destroy(struct rb_root
*root
)
1336 struct ubi_wl_entry
*e
;
1342 else if (rb
->rb_right
)
1345 e
= rb_entry(rb
, struct ubi_wl_entry
, rb
);
1349 if (rb
->rb_left
== &e
->rb
)
1352 rb
->rb_right
= NULL
;
1355 kmem_cache_free(ubi_wl_entry_slab
, e
);
1361 * ubi_thread - UBI background thread.
1362 * @u: the UBI device description object pointer
1364 int ubi_thread(void *u
)
1367 struct ubi_device
*ubi
= u
;
1369 ubi_msg("background thread \"%s\" started, PID %d",
1370 ubi
->bgt_name
, task_pid_nr(current
));
1376 if (kthread_should_stop())
1379 if (try_to_freeze())
1382 spin_lock(&ubi
->wl_lock
);
1383 if (list_empty(&ubi
->works
) || ubi
->ro_mode
||
1384 !ubi
->thread_enabled
) {
1385 set_current_state(TASK_INTERRUPTIBLE
);
1386 spin_unlock(&ubi
->wl_lock
);
1390 spin_unlock(&ubi
->wl_lock
);
1394 ubi_err("%s: work failed with error code %d",
1395 ubi
->bgt_name
, err
);
1396 if (failures
++ > WL_MAX_FAILURES
) {
1398 * Too many failures, disable the thread and
1399 * switch to read-only mode.
1401 ubi_msg("%s: %d consecutive failures",
1402 ubi
->bgt_name
, WL_MAX_FAILURES
);
1412 dbg_wl("background thread \"%s\" is killed", ubi
->bgt_name
);
1417 * cancel_pending - cancel all pending works.
1418 * @ubi: UBI device description object
1420 static void cancel_pending(struct ubi_device
*ubi
)
1422 while (!list_empty(&ubi
->works
)) {
1423 struct ubi_work
*wrk
;
1425 wrk
= list_entry(ubi
->works
.next
, struct ubi_work
, list
);
1426 list_del(&wrk
->list
);
1427 wrk
->func(ubi
, wrk
, 1);
1428 ubi
->works_count
-= 1;
1429 ubi_assert(ubi
->works_count
>= 0);
1434 * ubi_wl_init_scan - initialize the WL sub-system using scanning information.
1435 * @ubi: UBI device description object
1436 * @si: scanning information
1438 * This function returns zero in case of success, and a negative error code in
1441 int ubi_wl_init_scan(struct ubi_device
*ubi
, struct ubi_scan_info
*si
)
1444 struct rb_node
*rb1
, *rb2
;
1445 struct ubi_scan_volume
*sv
;
1446 struct ubi_scan_leb
*seb
, *tmp
;
1447 struct ubi_wl_entry
*e
;
1450 ubi
->used
= ubi
->free
= ubi
->scrub
= RB_ROOT
;
1451 ubi
->prot
.pnum
= ubi
->prot
.aec
= RB_ROOT
;
1452 spin_lock_init(&ubi
->wl_lock
);
1453 mutex_init(&ubi
->move_mutex
);
1454 init_rwsem(&ubi
->work_sem
);
1455 ubi
->max_ec
= si
->max_ec
;
1456 INIT_LIST_HEAD(&ubi
->works
);
1458 sprintf(ubi
->bgt_name
, UBI_BGT_NAME_PATTERN
, ubi
->ubi_num
);
1461 ubi
->lookuptbl
= kzalloc(ubi
->peb_count
* sizeof(void *), GFP_KERNEL
);
1462 if (!ubi
->lookuptbl
)
1465 list_for_each_entry_safe(seb
, tmp
, &si
->erase
, u
.list
) {
1468 e
= kmem_cache_alloc(ubi_wl_entry_slab
, GFP_KERNEL
);
1472 e
->pnum
= seb
->pnum
;
1474 ubi
->lookuptbl
[e
->pnum
] = e
;
1475 if (schedule_erase(ubi
, e
, 0)) {
1476 kmem_cache_free(ubi_wl_entry_slab
, e
);
1481 list_for_each_entry(seb
, &si
->free
, u
.list
) {
1484 e
= kmem_cache_alloc(ubi_wl_entry_slab
, GFP_KERNEL
);
1488 e
->pnum
= seb
->pnum
;
1490 ubi_assert(e
->ec
>= 0);
1491 wl_tree_add(e
, &ubi
->free
);
1492 ubi
->lookuptbl
[e
->pnum
] = e
;
1495 list_for_each_entry(seb
, &si
->corr
, u
.list
) {
1498 e
= kmem_cache_alloc(ubi_wl_entry_slab
, GFP_KERNEL
);
1502 e
->pnum
= seb
->pnum
;
1504 ubi
->lookuptbl
[e
->pnum
] = e
;
1505 if (schedule_erase(ubi
, e
, 0)) {
1506 kmem_cache_free(ubi_wl_entry_slab
, e
);
1511 ubi_rb_for_each_entry(rb1
, sv
, &si
->volumes
, rb
) {
1512 ubi_rb_for_each_entry(rb2
, seb
, &sv
->root
, u
.rb
) {
1515 e
= kmem_cache_alloc(ubi_wl_entry_slab
, GFP_KERNEL
);
1519 e
->pnum
= seb
->pnum
;
1521 ubi
->lookuptbl
[e
->pnum
] = e
;
1523 dbg_wl("add PEB %d EC %d to the used tree",
1525 wl_tree_add(e
, &ubi
->used
);
1527 dbg_wl("add PEB %d EC %d to the scrub tree",
1529 wl_tree_add(e
, &ubi
->scrub
);
1534 if (ubi
->avail_pebs
< WL_RESERVED_PEBS
) {
1535 ubi_err("no enough physical eraseblocks (%d, need %d)",
1536 ubi
->avail_pebs
, WL_RESERVED_PEBS
);
1539 ubi
->avail_pebs
-= WL_RESERVED_PEBS
;
1540 ubi
->rsvd_pebs
+= WL_RESERVED_PEBS
;
1542 /* Schedule wear-leveling if needed */
1543 err
= ensure_wear_leveling(ubi
);
1550 cancel_pending(ubi
);
1551 tree_destroy(&ubi
->used
);
1552 tree_destroy(&ubi
->free
);
1553 tree_destroy(&ubi
->scrub
);
1554 kfree(ubi
->lookuptbl
);
1559 * protection_trees_destroy - destroy the protection RB-trees.
1560 * @ubi: UBI device description object
1562 static void protection_trees_destroy(struct ubi_device
*ubi
)
1565 struct ubi_wl_prot_entry
*pe
;
1567 rb
= ubi
->prot
.aec
.rb_node
;
1571 else if (rb
->rb_right
)
1574 pe
= rb_entry(rb
, struct ubi_wl_prot_entry
, rb_aec
);
1578 if (rb
->rb_left
== &pe
->rb_aec
)
1581 rb
->rb_right
= NULL
;
1584 kmem_cache_free(ubi_wl_entry_slab
, pe
->e
);
1591 * ubi_wl_close - close the wear-leveling sub-system.
1592 * @ubi: UBI device description object
1594 void ubi_wl_close(struct ubi_device
*ubi
)
1596 dbg_wl("close the WL sub-system");
1597 cancel_pending(ubi
);
1598 protection_trees_destroy(ubi
);
1599 tree_destroy(&ubi
->used
);
1600 tree_destroy(&ubi
->free
);
1601 tree_destroy(&ubi
->scrub
);
1602 kfree(ubi
->lookuptbl
);
1605 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1608 * paranoid_check_ec - make sure that the erase counter of a physical eraseblock
1610 * @ubi: UBI device description object
1611 * @pnum: the physical eraseblock number to check
1612 * @ec: the erase counter to check
1614 * This function returns zero if the erase counter of physical eraseblock @pnum
1615 * is equivalent to @ec, %1 if not, and a negative error code if an error
1618 static int paranoid_check_ec(struct ubi_device
*ubi
, int pnum
, int ec
)
1622 struct ubi_ec_hdr
*ec_hdr
;
1624 ec_hdr
= kzalloc(ubi
->ec_hdr_alsize
, GFP_NOFS
);
1628 err
= ubi_io_read_ec_hdr(ubi
, pnum
, ec_hdr
, 0);
1629 if (err
&& err
!= UBI_IO_BITFLIPS
) {
1630 /* The header does not have to exist */
1635 read_ec
= be64_to_cpu(ec_hdr
->ec
);
1636 if (ec
!= read_ec
) {
1637 ubi_err("paranoid check failed for PEB %d", pnum
);
1638 ubi_err("read EC is %lld, should be %d", read_ec
, ec
);
1639 ubi_dbg_dump_stack();
1650 * paranoid_check_in_wl_tree - make sure that a wear-leveling entry is present
1652 * @e: the wear-leveling entry to check
1653 * @root: the root of the tree
1655 * This function returns zero if @e is in the @root RB-tree and %1 if it
1658 static int paranoid_check_in_wl_tree(struct ubi_wl_entry
*e
,
1659 struct rb_root
*root
)
1661 if (in_wl_tree(e
, root
))
1664 ubi_err("paranoid check failed for PEB %d, EC %d, RB-tree %p ",
1665 e
->pnum
, e
->ec
, root
);
1666 ubi_dbg_dump_stack();
1670 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */
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