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 * Author: Artem Bityutskiy (Битюцкий Артём)
22 * The UBI Eraseblock Association (EBA) unit.
24 * This unit is responsible for I/O to/from logical eraseblock.
26 * Although in this implementation the EBA table is fully kept and managed in
27 * RAM, which assumes poor scalability, it might be (partially) maintained on
28 * flash in future implementations.
30 * The EBA unit implements per-logical eraseblock locking. Before accessing a
31 * logical eraseblock it is locked for reading or writing. The per-logical
32 * eraseblock locking is implemented by means of the lock tree. The lock tree
33 * is an RB-tree which refers all the currently locked logical eraseblocks. The
34 * lock tree elements are &struct ubi_ltree_entry objects. They are indexed by
35 * (@vol_id, @lnum) pairs.
37 * EBA also maintains the global sequence counter which is incremented each
38 * time a logical eraseblock is mapped to a physical eraseblock and it is
39 * stored in the volume identifier header. This means that each VID header has
40 * a unique sequence number. The sequence number is only increased an we assume
41 * 64 bits is enough to never overflow.
44 #include <linux/slab.h>
45 #include <linux/crc32.h>
46 #include <linux/err.h>
49 /* Number of physical eraseblocks reserved for atomic LEB change operation */
50 #define EBA_RESERVED_PEBS 1
53 * next_sqnum - get next sequence number.
54 * @ubi: UBI device description object
56 * This function returns next sequence number to use, which is just the current
57 * global sequence counter value. It also increases the global sequence
60 static unsigned long long next_sqnum(struct ubi_device
*ubi
)
62 unsigned long long sqnum
;
64 spin_lock(&ubi
->ltree_lock
);
65 sqnum
= ubi
->global_sqnum
++;
66 spin_unlock(&ubi
->ltree_lock
);
72 * ubi_get_compat - get compatibility flags of a volume.
73 * @ubi: UBI device description object
76 * This function returns compatibility flags for an internal volume. User
77 * volumes have no compatibility flags, so %0 is returned.
79 static int ubi_get_compat(const struct ubi_device
*ubi
, int vol_id
)
81 if (vol_id
== UBI_LAYOUT_VOL_ID
)
82 return UBI_LAYOUT_VOLUME_COMPAT
;
87 * ltree_lookup - look up the lock tree.
88 * @ubi: UBI device description object
90 * @lnum: logical eraseblock number
92 * This function returns a pointer to the corresponding &struct ubi_ltree_entry
93 * object if the logical eraseblock is locked and %NULL if it is not.
94 * @ubi->ltree_lock has to be locked.
96 static struct ubi_ltree_entry
*ltree_lookup(struct ubi_device
*ubi
, int vol_id
,
101 p
= ubi
->ltree
.rb_node
;
103 struct ubi_ltree_entry
*le
;
105 le
= rb_entry(p
, struct ubi_ltree_entry
, rb
);
107 if (vol_id
< le
->vol_id
)
109 else if (vol_id
> le
->vol_id
)
114 else if (lnum
> le
->lnum
)
125 * ltree_add_entry - add new entry to the lock tree.
126 * @ubi: UBI device description object
128 * @lnum: logical eraseblock number
130 * This function adds new entry for logical eraseblock (@vol_id, @lnum) to the
131 * lock tree. If such entry is already there, its usage counter is increased.
132 * Returns pointer to the lock tree entry or %-ENOMEM if memory allocation
135 static struct ubi_ltree_entry
*ltree_add_entry(struct ubi_device
*ubi
,
136 int vol_id
, int lnum
)
138 struct ubi_ltree_entry
*le
, *le1
, *le_free
;
140 le
= kmem_cache_alloc(ubi_ltree_slab
, GFP_NOFS
);
142 return ERR_PTR(-ENOMEM
);
147 spin_lock(&ubi
->ltree_lock
);
148 le1
= ltree_lookup(ubi
, vol_id
, lnum
);
152 * This logical eraseblock is already locked. The newly
153 * allocated lock entry is not needed.
158 struct rb_node
**p
, *parent
= NULL
;
161 * No lock entry, add the newly allocated one to the
162 * @ubi->ltree RB-tree.
166 p
= &ubi
->ltree
.rb_node
;
169 le1
= rb_entry(parent
, struct ubi_ltree_entry
, rb
);
171 if (vol_id
< le1
->vol_id
)
173 else if (vol_id
> le1
->vol_id
)
176 ubi_assert(lnum
!= le1
->lnum
);
177 if (lnum
< le1
->lnum
)
184 rb_link_node(&le
->rb
, parent
, p
);
185 rb_insert_color(&le
->rb
, &ubi
->ltree
);
188 spin_unlock(&ubi
->ltree_lock
);
191 kmem_cache_free(ubi_ltree_slab
, le_free
);
197 * leb_read_lock - lock logical eraseblock for reading.
198 * @ubi: UBI device description object
200 * @lnum: logical eraseblock number
202 * This function locks a logical eraseblock for reading. Returns zero in case
203 * of success and a negative error code in case of failure.
205 static int leb_read_lock(struct ubi_device
*ubi
, int vol_id
, int lnum
)
207 struct ubi_ltree_entry
*le
;
209 le
= ltree_add_entry(ubi
, vol_id
, lnum
);
212 down_read(&le
->mutex
);
217 * leb_read_unlock - unlock logical eraseblock.
218 * @ubi: UBI device description object
220 * @lnum: logical eraseblock number
222 static void leb_read_unlock(struct ubi_device
*ubi
, int vol_id
, int lnum
)
225 struct ubi_ltree_entry
*le
;
227 spin_lock(&ubi
->ltree_lock
);
228 le
= ltree_lookup(ubi
, vol_id
, lnum
);
230 ubi_assert(le
->users
>= 0);
231 if (le
->users
== 0) {
232 rb_erase(&le
->rb
, &ubi
->ltree
);
235 spin_unlock(&ubi
->ltree_lock
);
239 kmem_cache_free(ubi_ltree_slab
, le
);
243 * leb_write_lock - lock logical eraseblock for writing.
244 * @ubi: UBI device description object
246 * @lnum: logical eraseblock number
248 * This function locks a logical eraseblock for writing. Returns zero in case
249 * of success and a negative error code in case of failure.
251 static int leb_write_lock(struct ubi_device
*ubi
, int vol_id
, int lnum
)
253 struct ubi_ltree_entry
*le
;
255 le
= ltree_add_entry(ubi
, vol_id
, lnum
);
258 down_write(&le
->mutex
);
263 * leb_write_lock - lock logical eraseblock for writing.
264 * @ubi: UBI device description object
266 * @lnum: logical eraseblock number
268 * This function locks a logical eraseblock for writing if there is no
269 * contention and does nothing if there is contention. Returns %0 in case of
270 * success, %1 in case of contention, and and a negative error code in case of
273 static int leb_write_trylock(struct ubi_device
*ubi
, int vol_id
, int lnum
)
276 struct ubi_ltree_entry
*le
;
278 le
= ltree_add_entry(ubi
, vol_id
, lnum
);
281 if (down_write_trylock(&le
->mutex
))
284 /* Contention, cancel */
285 spin_lock(&ubi
->ltree_lock
);
287 ubi_assert(le
->users
>= 0);
288 if (le
->users
== 0) {
289 rb_erase(&le
->rb
, &ubi
->ltree
);
293 spin_unlock(&ubi
->ltree_lock
);
295 kmem_cache_free(ubi_ltree_slab
, le
);
301 * leb_write_unlock - unlock logical eraseblock.
302 * @ubi: UBI device description object
304 * @lnum: logical eraseblock number
306 static void leb_write_unlock(struct ubi_device
*ubi
, int vol_id
, int lnum
)
309 struct ubi_ltree_entry
*le
;
311 spin_lock(&ubi
->ltree_lock
);
312 le
= ltree_lookup(ubi
, vol_id
, lnum
);
314 ubi_assert(le
->users
>= 0);
315 if (le
->users
== 0) {
316 rb_erase(&le
->rb
, &ubi
->ltree
);
320 spin_unlock(&ubi
->ltree_lock
);
322 up_write(&le
->mutex
);
324 kmem_cache_free(ubi_ltree_slab
, le
);
328 * ubi_eba_unmap_leb - un-map logical eraseblock.
329 * @ubi: UBI device description object
330 * @vol: volume description object
331 * @lnum: logical eraseblock number
333 * This function un-maps logical eraseblock @lnum and schedules corresponding
334 * physical eraseblock for erasure. Returns zero in case of success and a
335 * negative error code in case of failure.
337 int ubi_eba_unmap_leb(struct ubi_device
*ubi
, struct ubi_volume
*vol
,
340 int err
, pnum
, vol_id
= vol
->vol_id
;
342 ubi_assert(vol
->ref_count
> 0);
347 err
= leb_write_lock(ubi
, vol_id
, lnum
);
351 pnum
= vol
->eba_tbl
[lnum
];
353 /* This logical eraseblock is already unmapped */
356 dbg_eba("erase LEB %d:%d, PEB %d", vol_id
, lnum
, pnum
);
358 vol
->eba_tbl
[lnum
] = UBI_LEB_UNMAPPED
;
359 err
= ubi_wl_put_peb(ubi
, pnum
, 0);
362 leb_write_unlock(ubi
, vol_id
, lnum
);
367 * ubi_eba_read_leb - read data.
368 * @ubi: UBI device description object
369 * @vol: volume description object
370 * @lnum: logical eraseblock number
371 * @buf: buffer to store the read data
372 * @offset: offset from where to read
373 * @len: how many bytes to read
374 * @check: data CRC check flag
376 * If the logical eraseblock @lnum is unmapped, @buf is filled with 0xFF
377 * bytes. The @check flag only makes sense for static volumes and forces
378 * eraseblock data CRC checking.
380 * In case of success this function returns zero. In case of a static volume,
381 * if data CRC mismatches - %-EBADMSG is returned. %-EBADMSG may also be
382 * returned for any volume type if an ECC error was detected by the MTD device
383 * driver. Other negative error cored may be returned in case of other errors.
385 int ubi_eba_read_leb(struct ubi_device
*ubi
, struct ubi_volume
*vol
, int lnum
,
386 void *buf
, int offset
, int len
, int check
)
388 int err
, pnum
, scrub
= 0, vol_id
= vol
->vol_id
;
389 struct ubi_vid_hdr
*vid_hdr
;
390 uint32_t uninitialized_var(crc
);
392 ubi_assert(vol
->ref_count
> 0);
394 err
= leb_read_lock(ubi
, vol_id
, lnum
);
398 pnum
= vol
->eba_tbl
[lnum
];
401 * The logical eraseblock is not mapped, fill the whole buffer
402 * with 0xFF bytes. The exception is static volumes for which
403 * it is an error to read unmapped logical eraseblocks.
405 dbg_eba("read %d bytes from offset %d of LEB %d:%d (unmapped)",
406 len
, offset
, vol_id
, lnum
);
407 leb_read_unlock(ubi
, vol_id
, lnum
);
408 ubi_assert(vol
->vol_type
!= UBI_STATIC_VOLUME
);
409 memset(buf
, 0xFF, len
);
413 dbg_eba("read %d bytes from offset %d of LEB %d:%d, PEB %d",
414 len
, offset
, vol_id
, lnum
, pnum
);
416 if (vol
->vol_type
== UBI_DYNAMIC_VOLUME
)
421 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
427 err
= ubi_io_read_vid_hdr(ubi
, pnum
, vid_hdr
, 1);
428 if (err
&& err
!= UBI_IO_BITFLIPS
) {
431 * The header is either absent or corrupted.
432 * The former case means there is a bug -
433 * switch to read-only mode just in case.
434 * The latter case means a real corruption - we
435 * may try to recover data. FIXME: but this is
438 if (err
== UBI_IO_BAD_VID_HDR
) {
439 ubi_warn("bad VID header at PEB %d, LEB"
440 "%d:%d", pnum
, vol_id
, lnum
);
446 } else if (err
== UBI_IO_BITFLIPS
)
449 ubi_assert(lnum
< be32_to_cpu(vid_hdr
->used_ebs
));
450 ubi_assert(len
== be32_to_cpu(vid_hdr
->data_size
));
452 crc
= be32_to_cpu(vid_hdr
->data_crc
);
453 ubi_free_vid_hdr(ubi
, vid_hdr
);
456 err
= ubi_io_read_data(ubi
, buf
, pnum
, offset
, len
);
458 if (err
== UBI_IO_BITFLIPS
) {
461 } else if (err
== -EBADMSG
) {
462 if (vol
->vol_type
== UBI_DYNAMIC_VOLUME
)
466 ubi_msg("force data checking");
475 uint32_t crc1
= crc32(UBI_CRC32_INIT
, buf
, len
);
477 ubi_warn("CRC error: calculated %#08x, must be %#08x",
485 err
= ubi_wl_scrub_peb(ubi
, pnum
);
487 leb_read_unlock(ubi
, vol_id
, lnum
);
491 ubi_free_vid_hdr(ubi
, vid_hdr
);
493 leb_read_unlock(ubi
, vol_id
, lnum
);
498 * recover_peb - recover from write failure.
499 * @ubi: UBI device description object
500 * @pnum: the physical eraseblock to recover
502 * @lnum: logical eraseblock number
503 * @buf: data which was not written because of the write failure
504 * @offset: offset of the failed write
505 * @len: how many bytes should have been written
507 * This function is called in case of a write failure and moves all good data
508 * from the potentially bad physical eraseblock to a good physical eraseblock.
509 * This function also writes the data which was not written due to the failure.
510 * Returns new physical eraseblock number in case of success, and a negative
511 * error code in case of failure.
513 static int recover_peb(struct ubi_device
*ubi
, int pnum
, int vol_id
, int lnum
,
514 const void *buf
, int offset
, int len
)
516 int err
, idx
= vol_id2idx(ubi
, vol_id
), new_pnum
, data_size
, tries
= 0;
517 struct ubi_volume
*vol
= ubi
->volumes
[idx
];
518 struct ubi_vid_hdr
*vid_hdr
;
520 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
525 mutex_lock(&ubi
->buf_mutex
);
528 new_pnum
= ubi_wl_get_peb(ubi
, UBI_UNKNOWN
);
530 mutex_unlock(&ubi
->buf_mutex
);
531 ubi_free_vid_hdr(ubi
, vid_hdr
);
535 ubi_msg("recover PEB %d, move data to PEB %d", pnum
, new_pnum
);
537 err
= ubi_io_read_vid_hdr(ubi
, pnum
, vid_hdr
, 1);
538 if (err
&& err
!= UBI_IO_BITFLIPS
) {
544 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
545 err
= ubi_io_write_vid_hdr(ubi
, new_pnum
, vid_hdr
);
549 data_size
= offset
+ len
;
550 memset(ubi
->peb_buf1
+ offset
, 0xFF, len
);
552 /* Read everything before the area where the write failure happened */
554 err
= ubi_io_read_data(ubi
, ubi
->peb_buf1
, pnum
, 0, offset
);
555 if (err
&& err
!= UBI_IO_BITFLIPS
)
559 memcpy(ubi
->peb_buf1
+ offset
, buf
, len
);
561 err
= ubi_io_write_data(ubi
, ubi
->peb_buf1
, new_pnum
, 0, data_size
);
565 mutex_unlock(&ubi
->buf_mutex
);
566 ubi_free_vid_hdr(ubi
, vid_hdr
);
568 vol
->eba_tbl
[lnum
] = new_pnum
;
569 ubi_wl_put_peb(ubi
, pnum
, 1);
571 ubi_msg("data was successfully recovered");
575 mutex_unlock(&ubi
->buf_mutex
);
576 ubi_wl_put_peb(ubi
, new_pnum
, 1);
577 ubi_free_vid_hdr(ubi
, vid_hdr
);
582 * Bad luck? This physical eraseblock is bad too? Crud. Let's try to
585 ubi_warn("failed to write to PEB %d", new_pnum
);
586 ubi_wl_put_peb(ubi
, new_pnum
, 1);
587 if (++tries
> UBI_IO_RETRIES
) {
588 mutex_unlock(&ubi
->buf_mutex
);
589 ubi_free_vid_hdr(ubi
, vid_hdr
);
592 ubi_msg("try again");
597 * ubi_eba_write_leb - write data to dynamic volume.
598 * @ubi: UBI device description object
599 * @vol: volume description object
600 * @lnum: logical eraseblock number
601 * @buf: the data to write
602 * @offset: offset within the logical eraseblock where to write
603 * @len: how many bytes to write
606 * This function writes data to logical eraseblock @lnum of a dynamic volume
607 * @vol. Returns zero in case of success and a negative error code in case
608 * of failure. In case of error, it is possible that something was still
609 * written to the flash media, but may be some garbage.
611 int ubi_eba_write_leb(struct ubi_device
*ubi
, struct ubi_volume
*vol
, int lnum
,
612 const void *buf
, int offset
, int len
, int dtype
)
614 int err
, pnum
, tries
= 0, vol_id
= vol
->vol_id
;
615 struct ubi_vid_hdr
*vid_hdr
;
617 ubi_assert(vol
->ref_count
> 0);
622 err
= leb_write_lock(ubi
, vol_id
, lnum
);
626 pnum
= vol
->eba_tbl
[lnum
];
628 dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d",
629 len
, offset
, vol_id
, lnum
, pnum
);
631 err
= ubi_io_write_data(ubi
, buf
, pnum
, offset
, len
);
633 ubi_warn("failed to write data to PEB %d", pnum
);
634 if (err
== -EIO
&& ubi
->bad_allowed
)
635 err
= recover_peb(ubi
, pnum
, vol_id
, lnum
, buf
,
640 leb_write_unlock(ubi
, vol_id
, lnum
);
645 * The logical eraseblock is not mapped. We have to get a free physical
646 * eraseblock and write the volume identifier header there first.
648 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
650 leb_write_unlock(ubi
, vol_id
, lnum
);
654 vid_hdr
->vol_type
= UBI_VID_DYNAMIC
;
655 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
656 vid_hdr
->vol_id
= cpu_to_be32(vol_id
);
657 vid_hdr
->lnum
= cpu_to_be32(lnum
);
658 vid_hdr
->compat
= ubi_get_compat(ubi
, vol_id
);
659 vid_hdr
->data_pad
= cpu_to_be32(vol
->data_pad
);
662 pnum
= ubi_wl_get_peb(ubi
, dtype
);
664 ubi_free_vid_hdr(ubi
, vid_hdr
);
665 leb_write_unlock(ubi
, vol_id
, lnum
);
669 dbg_eba("write VID hdr and %d bytes at offset %d of LEB %d:%d, PEB %d",
670 len
, offset
, vol_id
, lnum
, pnum
);
672 err
= ubi_io_write_vid_hdr(ubi
, pnum
, vid_hdr
);
674 ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
680 err
= ubi_io_write_data(ubi
, buf
, pnum
, offset
, len
);
682 ubi_warn("failed to write %d bytes at offset %d of "
683 "LEB %d:%d, PEB %d", len
, offset
, vol_id
,
689 vol
->eba_tbl
[lnum
] = pnum
;
691 leb_write_unlock(ubi
, vol_id
, lnum
);
692 ubi_free_vid_hdr(ubi
, vid_hdr
);
696 if (err
!= -EIO
|| !ubi
->bad_allowed
) {
698 leb_write_unlock(ubi
, vol_id
, lnum
);
699 ubi_free_vid_hdr(ubi
, vid_hdr
);
704 * Fortunately, this is the first write operation to this physical
705 * eraseblock, so just put it and request a new one. We assume that if
706 * this physical eraseblock went bad, the erase code will handle that.
708 err
= ubi_wl_put_peb(ubi
, pnum
, 1);
709 if (err
|| ++tries
> UBI_IO_RETRIES
) {
711 leb_write_unlock(ubi
, vol_id
, lnum
);
712 ubi_free_vid_hdr(ubi
, vid_hdr
);
716 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
717 ubi_msg("try another PEB");
722 * ubi_eba_write_leb_st - write data to static volume.
723 * @ubi: UBI device description object
724 * @vol: volume description object
725 * @lnum: logical eraseblock number
726 * @buf: data to write
727 * @len: how many bytes to write
729 * @used_ebs: how many logical eraseblocks will this volume contain
731 * This function writes data to logical eraseblock @lnum of static volume
732 * @vol. The @used_ebs argument should contain total number of logical
733 * eraseblock in this static volume.
735 * When writing to the last logical eraseblock, the @len argument doesn't have
736 * to be aligned to the minimal I/O unit size. Instead, it has to be equivalent
737 * to the real data size, although the @buf buffer has to contain the
738 * alignment. In all other cases, @len has to be aligned.
740 * It is prohibited to write more then once to logical eraseblocks of static
741 * volumes. This function returns zero in case of success and a negative error
742 * code in case of failure.
744 int ubi_eba_write_leb_st(struct ubi_device
*ubi
, struct ubi_volume
*vol
,
745 int lnum
, const void *buf
, int len
, int dtype
,
748 int err
, pnum
, tries
= 0, data_size
= len
, vol_id
= vol
->vol_id
;
749 struct ubi_vid_hdr
*vid_hdr
;
752 ubi_assert(vol
->ref_count
> 0);
757 if (lnum
== used_ebs
- 1)
758 /* If this is the last LEB @len may be unaligned */
759 len
= ALIGN(data_size
, ubi
->min_io_size
);
761 ubi_assert(len
% ubi
->min_io_size
== 0);
763 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
767 err
= leb_write_lock(ubi
, vol_id
, lnum
);
769 ubi_free_vid_hdr(ubi
, vid_hdr
);
773 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
774 vid_hdr
->vol_id
= cpu_to_be32(vol_id
);
775 vid_hdr
->lnum
= cpu_to_be32(lnum
);
776 vid_hdr
->compat
= ubi_get_compat(ubi
, vol_id
);
777 vid_hdr
->data_pad
= cpu_to_be32(vol
->data_pad
);
779 crc
= crc32(UBI_CRC32_INIT
, buf
, data_size
);
780 vid_hdr
->vol_type
= UBI_VID_STATIC
;
781 vid_hdr
->data_size
= cpu_to_be32(data_size
);
782 vid_hdr
->used_ebs
= cpu_to_be32(used_ebs
);
783 vid_hdr
->data_crc
= cpu_to_be32(crc
);
786 pnum
= ubi_wl_get_peb(ubi
, dtype
);
788 ubi_free_vid_hdr(ubi
, vid_hdr
);
789 leb_write_unlock(ubi
, vol_id
, lnum
);
793 dbg_eba("write VID hdr and %d bytes at LEB %d:%d, PEB %d, used_ebs %d",
794 len
, vol_id
, lnum
, pnum
, used_ebs
);
796 err
= ubi_io_write_vid_hdr(ubi
, pnum
, vid_hdr
);
798 ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
803 err
= ubi_io_write_data(ubi
, buf
, pnum
, 0, len
);
805 ubi_warn("failed to write %d bytes of data to PEB %d",
810 ubi_assert(vol
->eba_tbl
[lnum
] < 0);
811 vol
->eba_tbl
[lnum
] = pnum
;
813 leb_write_unlock(ubi
, vol_id
, lnum
);
814 ubi_free_vid_hdr(ubi
, vid_hdr
);
818 if (err
!= -EIO
|| !ubi
->bad_allowed
) {
820 * This flash device does not admit of bad eraseblocks or
821 * something nasty and unexpected happened. Switch to read-only
825 leb_write_unlock(ubi
, vol_id
, lnum
);
826 ubi_free_vid_hdr(ubi
, vid_hdr
);
830 err
= ubi_wl_put_peb(ubi
, pnum
, 1);
831 if (err
|| ++tries
> UBI_IO_RETRIES
) {
833 leb_write_unlock(ubi
, vol_id
, lnum
);
834 ubi_free_vid_hdr(ubi
, vid_hdr
);
838 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
839 ubi_msg("try another PEB");
844 * ubi_eba_atomic_leb_change - change logical eraseblock atomically.
845 * @ubi: UBI device description object
846 * @vol: volume description object
847 * @lnum: logical eraseblock number
848 * @buf: data to write
849 * @len: how many bytes to write
852 * This function changes the contents of a logical eraseblock atomically. @buf
853 * has to contain new logical eraseblock data, and @len - the length of the
854 * data, which has to be aligned. This function guarantees that in case of an
855 * unclean reboot the old contents is preserved. Returns zero in case of
856 * success and a negative error code in case of failure.
858 * UBI reserves one LEB for the "atomic LEB change" operation, so only one
859 * LEB change may be done at a time. This is ensured by @ubi->alc_mutex.
861 int ubi_eba_atomic_leb_change(struct ubi_device
*ubi
, struct ubi_volume
*vol
,
862 int lnum
, const void *buf
, int len
, int dtype
)
864 int err
, pnum
, tries
= 0, vol_id
= vol
->vol_id
;
865 struct ubi_vid_hdr
*vid_hdr
;
868 ubi_assert(vol
->ref_count
> 0);
873 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
877 mutex_lock(&ubi
->alc_mutex
);
878 err
= leb_write_lock(ubi
, vol_id
, lnum
);
882 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
883 vid_hdr
->vol_id
= cpu_to_be32(vol_id
);
884 vid_hdr
->lnum
= cpu_to_be32(lnum
);
885 vid_hdr
->compat
= ubi_get_compat(ubi
, vol_id
);
886 vid_hdr
->data_pad
= cpu_to_be32(vol
->data_pad
);
888 crc
= crc32(UBI_CRC32_INIT
, buf
, len
);
889 vid_hdr
->vol_type
= UBI_VID_DYNAMIC
;
890 vid_hdr
->data_size
= cpu_to_be32(len
);
891 vid_hdr
->copy_flag
= 1;
892 vid_hdr
->data_crc
= cpu_to_be32(crc
);
895 pnum
= ubi_wl_get_peb(ubi
, dtype
);
901 dbg_eba("change LEB %d:%d, PEB %d, write VID hdr to PEB %d",
902 vol_id
, lnum
, vol
->eba_tbl
[lnum
], pnum
);
904 err
= ubi_io_write_vid_hdr(ubi
, pnum
, vid_hdr
);
906 ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
911 err
= ubi_io_write_data(ubi
, buf
, pnum
, 0, len
);
913 ubi_warn("failed to write %d bytes of data to PEB %d",
918 if (vol
->eba_tbl
[lnum
] >= 0) {
919 err
= ubi_wl_put_peb(ubi
, vol
->eba_tbl
[lnum
], 1);
924 vol
->eba_tbl
[lnum
] = pnum
;
927 leb_write_unlock(ubi
, vol_id
, lnum
);
929 mutex_unlock(&ubi
->alc_mutex
);
930 ubi_free_vid_hdr(ubi
, vid_hdr
);
934 if (err
!= -EIO
|| !ubi
->bad_allowed
) {
936 * This flash device does not admit of bad eraseblocks or
937 * something nasty and unexpected happened. Switch to read-only
944 err
= ubi_wl_put_peb(ubi
, pnum
, 1);
945 if (err
|| ++tries
> UBI_IO_RETRIES
) {
950 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
951 ubi_msg("try another PEB");
956 * ubi_eba_copy_leb - copy logical eraseblock.
957 * @ubi: UBI device description object
958 * @from: physical eraseblock number from where to copy
959 * @to: physical eraseblock number where to copy
960 * @vid_hdr: VID header of the @from physical eraseblock
962 * This function copies logical eraseblock from physical eraseblock @from to
963 * physical eraseblock @to. The @vid_hdr buffer may be changed by this
965 * o %0 in case of success;
966 * o %1 if the operation was canceled and should be tried later (e.g.,
967 * because a bit-flip was detected at the target PEB);
968 * o %2 if the volume is being deleted and this LEB should not be moved.
970 int ubi_eba_copy_leb(struct ubi_device
*ubi
, int from
, int to
,
971 struct ubi_vid_hdr
*vid_hdr
)
973 int err
, vol_id
, lnum
, data_size
, aldata_size
, idx
;
974 struct ubi_volume
*vol
;
977 vol_id
= be32_to_cpu(vid_hdr
->vol_id
);
978 lnum
= be32_to_cpu(vid_hdr
->lnum
);
980 dbg_eba("copy LEB %d:%d, PEB %d to PEB %d", vol_id
, lnum
, from
, to
);
982 if (vid_hdr
->vol_type
== UBI_VID_STATIC
) {
983 data_size
= be32_to_cpu(vid_hdr
->data_size
);
984 aldata_size
= ALIGN(data_size
, ubi
->min_io_size
);
986 data_size
= aldata_size
=
987 ubi
->leb_size
- be32_to_cpu(vid_hdr
->data_pad
);
989 idx
= vol_id2idx(ubi
, vol_id
);
990 spin_lock(&ubi
->volumes_lock
);
992 * Note, we may race with volume deletion, which means that the volume
993 * this logical eraseblock belongs to might be being deleted. Since the
994 * volume deletion unmaps all the volume's logical eraseblocks, it will
995 * be locked in 'ubi_wl_put_peb()' and wait for the WL worker to finish.
997 vol
= ubi
->volumes
[idx
];
999 /* No need to do further work, cancel */
1000 dbg_eba("volume %d is being removed, cancel", vol_id
);
1001 spin_unlock(&ubi
->volumes_lock
);
1004 spin_unlock(&ubi
->volumes_lock
);
1007 * We do not want anybody to write to this logical eraseblock while we
1008 * are moving it, so lock it.
1010 * Note, we are using non-waiting locking here, because we cannot sleep
1011 * on the LEB, since it may cause deadlocks. Indeed, imagine a task is
1012 * unmapping the LEB which is mapped to the PEB we are going to move
1013 * (@from). This task locks the LEB and goes sleep in the
1014 * 'ubi_wl_put_peb()' function on the @ubi->move_mutex. In turn, we are
1015 * holding @ubi->move_mutex and go sleep on the LEB lock. So, if the
1016 * LEB is already locked, we just do not move it and return %1.
1018 err
= leb_write_trylock(ubi
, vol_id
, lnum
);
1020 dbg_eba("contention on LEB %d:%d, cancel", vol_id
, lnum
);
1025 * The LEB might have been put meanwhile, and the task which put it is
1026 * probably waiting on @ubi->move_mutex. No need to continue the work,
1029 if (vol
->eba_tbl
[lnum
] != from
) {
1030 dbg_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to "
1031 "PEB %d, cancel", vol_id
, lnum
, from
,
1032 vol
->eba_tbl
[lnum
]);
1034 goto out_unlock_leb
;
1038 * OK, now the LEB is locked and we can safely start moving iy. Since
1039 * this function utilizes thie @ubi->peb1_buf buffer which is shared
1040 * with some other functions, so lock the buffer by taking the
1043 mutex_lock(&ubi
->buf_mutex
);
1044 dbg_eba("read %d bytes of data", aldata_size
);
1045 err
= ubi_io_read_data(ubi
, ubi
->peb_buf1
, from
, 0, aldata_size
);
1046 if (err
&& err
!= UBI_IO_BITFLIPS
) {
1047 ubi_warn("error %d while reading data from PEB %d",
1049 goto out_unlock_buf
;
1053 * Now we have got to calculate how much data we have to to copy. In
1054 * case of a static volume it is fairly easy - the VID header contains
1055 * the data size. In case of a dynamic volume it is more difficult - we
1056 * have to read the contents, cut 0xFF bytes from the end and copy only
1057 * the first part. We must do this to avoid writing 0xFF bytes as it
1058 * may have some side-effects. And not only this. It is important not
1059 * to include those 0xFFs to CRC because later the they may be filled
1062 if (vid_hdr
->vol_type
== UBI_VID_DYNAMIC
)
1063 aldata_size
= data_size
=
1064 ubi_calc_data_len(ubi
, ubi
->peb_buf1
, data_size
);
1067 crc
= crc32(UBI_CRC32_INIT
, ubi
->peb_buf1
, data_size
);
1071 * It may turn out to me that the whole @from physical eraseblock
1072 * contains only 0xFF bytes. Then we have to only write the VID header
1073 * and do not write any data. This also means we should not set
1074 * @vid_hdr->copy_flag, @vid_hdr->data_size, and @vid_hdr->data_crc.
1076 if (data_size
> 0) {
1077 vid_hdr
->copy_flag
= 1;
1078 vid_hdr
->data_size
= cpu_to_be32(data_size
);
1079 vid_hdr
->data_crc
= cpu_to_be32(crc
);
1081 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
1083 err
= ubi_io_write_vid_hdr(ubi
, to
, vid_hdr
);
1085 goto out_unlock_buf
;
1089 /* Read the VID header back and check if it was written correctly */
1090 err
= ubi_io_read_vid_hdr(ubi
, to
, vid_hdr
, 1);
1092 if (err
!= UBI_IO_BITFLIPS
)
1093 ubi_warn("cannot read VID header back from PEB %d", to
);
1096 goto out_unlock_buf
;
1099 if (data_size
> 0) {
1100 err
= ubi_io_write_data(ubi
, ubi
->peb_buf1
, to
, 0, aldata_size
);
1102 goto out_unlock_buf
;
1107 * We've written the data and are going to read it back to make
1108 * sure it was written correctly.
1111 err
= ubi_io_read_data(ubi
, ubi
->peb_buf2
, to
, 0, aldata_size
);
1113 if (err
!= UBI_IO_BITFLIPS
)
1114 ubi_warn("cannot read data back from PEB %d",
1118 goto out_unlock_buf
;
1123 if (memcmp(ubi
->peb_buf1
, ubi
->peb_buf2
, aldata_size
)) {
1124 ubi_warn("read data back from PEB %d - it is different",
1126 goto out_unlock_buf
;
1130 ubi_assert(vol
->eba_tbl
[lnum
] == from
);
1131 vol
->eba_tbl
[lnum
] = to
;
1134 mutex_unlock(&ubi
->buf_mutex
);
1136 leb_write_unlock(ubi
, vol_id
, lnum
);
1141 * ubi_eba_init_scan - initialize the EBA unit using scanning information.
1142 * @ubi: UBI device description object
1143 * @si: scanning information
1145 * This function returns zero in case of success and a negative error code in
1148 int ubi_eba_init_scan(struct ubi_device
*ubi
, struct ubi_scan_info
*si
)
1150 int i
, j
, err
, num_volumes
;
1151 struct ubi_scan_volume
*sv
;
1152 struct ubi_volume
*vol
;
1153 struct ubi_scan_leb
*seb
;
1156 dbg_eba("initialize EBA unit");
1158 spin_lock_init(&ubi
->ltree_lock
);
1159 mutex_init(&ubi
->alc_mutex
);
1160 ubi
->ltree
= RB_ROOT
;
1162 ubi
->global_sqnum
= si
->max_sqnum
+ 1;
1163 num_volumes
= ubi
->vtbl_slots
+ UBI_INT_VOL_COUNT
;
1165 for (i
= 0; i
< num_volumes
; i
++) {
1166 vol
= ubi
->volumes
[i
];
1172 vol
->eba_tbl
= kmalloc(vol
->reserved_pebs
* sizeof(int),
1174 if (!vol
->eba_tbl
) {
1179 for (j
= 0; j
< vol
->reserved_pebs
; j
++)
1180 vol
->eba_tbl
[j
] = UBI_LEB_UNMAPPED
;
1182 sv
= ubi_scan_find_sv(si
, idx2vol_id(ubi
, i
));
1186 ubi_rb_for_each_entry(rb
, seb
, &sv
->root
, u
.rb
) {
1187 if (seb
->lnum
>= vol
->reserved_pebs
)
1189 * This may happen in case of an unclean reboot
1192 ubi_scan_move_to_list(sv
, seb
, &si
->erase
);
1193 vol
->eba_tbl
[seb
->lnum
] = seb
->pnum
;
1197 if (ubi
->avail_pebs
< EBA_RESERVED_PEBS
) {
1198 ubi_err("no enough physical eraseblocks (%d, need %d)",
1199 ubi
->avail_pebs
, EBA_RESERVED_PEBS
);
1203 ubi
->avail_pebs
-= EBA_RESERVED_PEBS
;
1204 ubi
->rsvd_pebs
+= EBA_RESERVED_PEBS
;
1206 if (ubi
->bad_allowed
) {
1207 ubi_calculate_reserved(ubi
);
1209 if (ubi
->avail_pebs
< ubi
->beb_rsvd_level
) {
1210 /* No enough free physical eraseblocks */
1211 ubi
->beb_rsvd_pebs
= ubi
->avail_pebs
;
1212 ubi_warn("cannot reserve enough PEBs for bad PEB "
1213 "handling, reserved %d, need %d",
1214 ubi
->beb_rsvd_pebs
, ubi
->beb_rsvd_level
);
1216 ubi
->beb_rsvd_pebs
= ubi
->beb_rsvd_level
;
1218 ubi
->avail_pebs
-= ubi
->beb_rsvd_pebs
;
1219 ubi
->rsvd_pebs
+= ubi
->beb_rsvd_pebs
;
1222 dbg_eba("EBA unit is initialized");
1226 for (i
= 0; i
< num_volumes
; i
++) {
1227 if (!ubi
->volumes
[i
])
1229 kfree(ubi
->volumes
[i
]->eba_tbl
);
1235 * ubi_eba_close - close EBA unit.
1236 * @ubi: UBI device description object
1238 void ubi_eba_close(const struct ubi_device
*ubi
)
1240 int i
, num_volumes
= ubi
->vtbl_slots
+ UBI_INT_VOL_COUNT
;
1242 dbg_eba("close EBA unit");
1244 for (i
= 0; i
< num_volumes
; i
++) {
1245 if (!ubi
->volumes
[i
])
1247 kfree(ubi
->volumes
[i
]->eba_tbl
);
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