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_unlock - unlock logical eraseblock.
264 * @ubi: UBI device description object
266 * @lnum: logical eraseblock number
268 static void leb_write_unlock(struct ubi_device
*ubi
, int vol_id
, int lnum
)
271 struct ubi_ltree_entry
*le
;
273 spin_lock(&ubi
->ltree_lock
);
274 le
= ltree_lookup(ubi
, vol_id
, lnum
);
276 ubi_assert(le
->users
>= 0);
277 if (le
->users
== 0) {
278 rb_erase(&le
->rb
, &ubi
->ltree
);
282 spin_unlock(&ubi
->ltree_lock
);
284 up_write(&le
->mutex
);
286 kmem_cache_free(ubi_ltree_slab
, le
);
290 * ubi_eba_unmap_leb - un-map logical eraseblock.
291 * @ubi: UBI device description object
292 * @vol: volume description object
293 * @lnum: logical eraseblock number
295 * This function un-maps logical eraseblock @lnum and schedules corresponding
296 * physical eraseblock for erasure. Returns zero in case of success and a
297 * negative error code in case of failure.
299 int ubi_eba_unmap_leb(struct ubi_device
*ubi
, struct ubi_volume
*vol
,
302 int err
, pnum
, vol_id
= vol
->vol_id
;
307 err
= leb_write_lock(ubi
, vol_id
, lnum
);
311 pnum
= vol
->eba_tbl
[lnum
];
313 /* This logical eraseblock is already unmapped */
316 dbg_eba("erase LEB %d:%d, PEB %d", vol_id
, lnum
, pnum
);
318 vol
->eba_tbl
[lnum
] = UBI_LEB_UNMAPPED
;
319 err
= ubi_wl_put_peb(ubi
, pnum
, 0);
322 leb_write_unlock(ubi
, vol_id
, lnum
);
327 * ubi_eba_read_leb - read data.
328 * @ubi: UBI device description object
329 * @vol: volume description object
330 * @lnum: logical eraseblock number
331 * @buf: buffer to store the read data
332 * @offset: offset from where to read
333 * @len: how many bytes to read
334 * @check: data CRC check flag
336 * If the logical eraseblock @lnum is unmapped, @buf is filled with 0xFF
337 * bytes. The @check flag only makes sense for static volumes and forces
338 * eraseblock data CRC checking.
340 * In case of success this function returns zero. In case of a static volume,
341 * if data CRC mismatches - %-EBADMSG is returned. %-EBADMSG may also be
342 * returned for any volume type if an ECC error was detected by the MTD device
343 * driver. Other negative error cored may be returned in case of other errors.
345 int ubi_eba_read_leb(struct ubi_device
*ubi
, struct ubi_volume
*vol
, int lnum
,
346 void *buf
, int offset
, int len
, int check
)
348 int err
, pnum
, scrub
= 0, vol_id
= vol
->vol_id
;
349 struct ubi_vid_hdr
*vid_hdr
;
350 uint32_t uninitialized_var(crc
);
352 err
= leb_read_lock(ubi
, vol_id
, lnum
);
356 pnum
= vol
->eba_tbl
[lnum
];
359 * The logical eraseblock is not mapped, fill the whole buffer
360 * with 0xFF bytes. The exception is static volumes for which
361 * it is an error to read unmapped logical eraseblocks.
363 dbg_eba("read %d bytes from offset %d of LEB %d:%d (unmapped)",
364 len
, offset
, vol_id
, lnum
);
365 leb_read_unlock(ubi
, vol_id
, lnum
);
366 ubi_assert(vol
->vol_type
!= UBI_STATIC_VOLUME
);
367 memset(buf
, 0xFF, len
);
371 dbg_eba("read %d bytes from offset %d of LEB %d:%d, PEB %d",
372 len
, offset
, vol_id
, lnum
, pnum
);
374 if (vol
->vol_type
== UBI_DYNAMIC_VOLUME
)
379 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
385 err
= ubi_io_read_vid_hdr(ubi
, pnum
, vid_hdr
, 1);
386 if (err
&& err
!= UBI_IO_BITFLIPS
) {
389 * The header is either absent or corrupted.
390 * The former case means there is a bug -
391 * switch to read-only mode just in case.
392 * The latter case means a real corruption - we
393 * may try to recover data. FIXME: but this is
396 if (err
== UBI_IO_BAD_VID_HDR
) {
397 ubi_warn("bad VID header at PEB %d, LEB"
398 "%d:%d", pnum
, vol_id
, lnum
);
404 } else if (err
== UBI_IO_BITFLIPS
)
407 ubi_assert(lnum
< be32_to_cpu(vid_hdr
->used_ebs
));
408 ubi_assert(len
== be32_to_cpu(vid_hdr
->data_size
));
410 crc
= be32_to_cpu(vid_hdr
->data_crc
);
411 ubi_free_vid_hdr(ubi
, vid_hdr
);
414 err
= ubi_io_read_data(ubi
, buf
, pnum
, offset
, len
);
416 if (err
== UBI_IO_BITFLIPS
) {
419 } else if (err
== -EBADMSG
) {
420 if (vol
->vol_type
== UBI_DYNAMIC_VOLUME
)
424 ubi_msg("force data checking");
433 uint32_t crc1
= crc32(UBI_CRC32_INIT
, buf
, len
);
435 ubi_warn("CRC error: calculated %#08x, must be %#08x",
443 err
= ubi_wl_scrub_peb(ubi
, pnum
);
445 leb_read_unlock(ubi
, vol_id
, lnum
);
449 ubi_free_vid_hdr(ubi
, vid_hdr
);
451 leb_read_unlock(ubi
, vol_id
, lnum
);
456 * recover_peb - recover from write failure.
457 * @ubi: UBI device description object
458 * @pnum: the physical eraseblock to recover
460 * @lnum: logical eraseblock number
461 * @buf: data which was not written because of the write failure
462 * @offset: offset of the failed write
463 * @len: how many bytes should have been written
465 * This function is called in case of a write failure and moves all good data
466 * from the potentially bad physical eraseblock to a good physical eraseblock.
467 * This function also writes the data which was not written due to the failure.
468 * Returns new physical eraseblock number in case of success, and a negative
469 * error code in case of failure.
471 static int recover_peb(struct ubi_device
*ubi
, int pnum
, int vol_id
, int lnum
,
472 const void *buf
, int offset
, int len
)
474 int err
, idx
= vol_id2idx(ubi
, vol_id
), new_pnum
, data_size
, tries
= 0;
475 struct ubi_volume
*vol
= ubi
->volumes
[idx
];
476 struct ubi_vid_hdr
*vid_hdr
;
478 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
483 mutex_lock(&ubi
->buf_mutex
);
486 new_pnum
= ubi_wl_get_peb(ubi
, UBI_UNKNOWN
);
488 mutex_unlock(&ubi
->buf_mutex
);
489 ubi_free_vid_hdr(ubi
, vid_hdr
);
493 ubi_msg("recover PEB %d, move data to PEB %d", pnum
, new_pnum
);
495 err
= ubi_io_read_vid_hdr(ubi
, pnum
, vid_hdr
, 1);
496 if (err
&& err
!= UBI_IO_BITFLIPS
) {
502 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
503 err
= ubi_io_write_vid_hdr(ubi
, new_pnum
, vid_hdr
);
507 data_size
= offset
+ len
;
508 memset(ubi
->peb_buf1
+ offset
, 0xFF, len
);
510 /* Read everything before the area where the write failure happened */
512 err
= ubi_io_read_data(ubi
, ubi
->peb_buf1
, pnum
, 0, offset
);
513 if (err
&& err
!= UBI_IO_BITFLIPS
)
517 memcpy(ubi
->peb_buf1
+ offset
, buf
, len
);
519 err
= ubi_io_write_data(ubi
, ubi
->peb_buf1
, new_pnum
, 0, data_size
);
523 mutex_unlock(&ubi
->buf_mutex
);
524 ubi_free_vid_hdr(ubi
, vid_hdr
);
526 vol
->eba_tbl
[lnum
] = new_pnum
;
527 ubi_wl_put_peb(ubi
, pnum
, 1);
529 ubi_msg("data was successfully recovered");
533 mutex_unlock(&ubi
->buf_mutex
);
534 ubi_wl_put_peb(ubi
, new_pnum
, 1);
535 ubi_free_vid_hdr(ubi
, vid_hdr
);
540 * Bad luck? This physical eraseblock is bad too? Crud. Let's try to
543 ubi_warn("failed to write to PEB %d", new_pnum
);
544 ubi_wl_put_peb(ubi
, new_pnum
, 1);
545 if (++tries
> UBI_IO_RETRIES
) {
546 mutex_unlock(&ubi
->buf_mutex
);
547 ubi_free_vid_hdr(ubi
, vid_hdr
);
550 ubi_msg("try again");
555 * ubi_eba_write_leb - write data to dynamic volume.
556 * @ubi: UBI device description object
557 * @vol: volume description object
558 * @lnum: logical eraseblock number
559 * @buf: the data to write
560 * @offset: offset within the logical eraseblock where to write
561 * @len: how many bytes to write
564 * This function writes data to logical eraseblock @lnum of a dynamic volume
565 * @vol. Returns zero in case of success and a negative error code in case
566 * of failure. In case of error, it is possible that something was still
567 * written to the flash media, but may be some garbage.
569 int ubi_eba_write_leb(struct ubi_device
*ubi
, struct ubi_volume
*vol
, int lnum
,
570 const void *buf
, int offset
, int len
, int dtype
)
572 int err
, pnum
, tries
= 0, vol_id
= vol
->vol_id
;
573 struct ubi_vid_hdr
*vid_hdr
;
578 err
= leb_write_lock(ubi
, vol_id
, lnum
);
582 pnum
= vol
->eba_tbl
[lnum
];
584 dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d",
585 len
, offset
, vol_id
, lnum
, pnum
);
587 err
= ubi_io_write_data(ubi
, buf
, pnum
, offset
, len
);
589 ubi_warn("failed to write data to PEB %d", pnum
);
590 if (err
== -EIO
&& ubi
->bad_allowed
)
591 err
= recover_peb(ubi
, pnum
, vol_id
, lnum
, buf
,
596 leb_write_unlock(ubi
, vol_id
, lnum
);
601 * The logical eraseblock is not mapped. We have to get a free physical
602 * eraseblock and write the volume identifier header there first.
604 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
606 leb_write_unlock(ubi
, vol_id
, lnum
);
610 vid_hdr
->vol_type
= UBI_VID_DYNAMIC
;
611 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
612 vid_hdr
->vol_id
= cpu_to_be32(vol_id
);
613 vid_hdr
->lnum
= cpu_to_be32(lnum
);
614 vid_hdr
->compat
= ubi_get_compat(ubi
, vol_id
);
615 vid_hdr
->data_pad
= cpu_to_be32(vol
->data_pad
);
618 pnum
= ubi_wl_get_peb(ubi
, dtype
);
620 ubi_free_vid_hdr(ubi
, vid_hdr
);
621 leb_write_unlock(ubi
, vol_id
, lnum
);
625 dbg_eba("write VID hdr and %d bytes at offset %d of LEB %d:%d, PEB %d",
626 len
, offset
, vol_id
, lnum
, pnum
);
628 err
= ubi_io_write_vid_hdr(ubi
, pnum
, vid_hdr
);
630 ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
636 err
= ubi_io_write_data(ubi
, buf
, pnum
, offset
, len
);
638 ubi_warn("failed to write %d bytes at offset %d of "
639 "LEB %d:%d, PEB %d", len
, offset
, vol_id
,
645 vol
->eba_tbl
[lnum
] = pnum
;
647 leb_write_unlock(ubi
, vol_id
, lnum
);
648 ubi_free_vid_hdr(ubi
, vid_hdr
);
652 if (err
!= -EIO
|| !ubi
->bad_allowed
) {
654 leb_write_unlock(ubi
, vol_id
, lnum
);
655 ubi_free_vid_hdr(ubi
, vid_hdr
);
660 * Fortunately, this is the first write operation to this physical
661 * eraseblock, so just put it and request a new one. We assume that if
662 * this physical eraseblock went bad, the erase code will handle that.
664 err
= ubi_wl_put_peb(ubi
, pnum
, 1);
665 if (err
|| ++tries
> UBI_IO_RETRIES
) {
667 leb_write_unlock(ubi
, vol_id
, lnum
);
668 ubi_free_vid_hdr(ubi
, vid_hdr
);
672 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
673 ubi_msg("try another PEB");
678 * ubi_eba_write_leb_st - write data to static volume.
679 * @ubi: UBI device description object
680 * @vol: volume description object
681 * @lnum: logical eraseblock number
682 * @buf: data to write
683 * @len: how many bytes to write
685 * @used_ebs: how many logical eraseblocks will this volume contain
687 * This function writes data to logical eraseblock @lnum of static volume
688 * @vol. The @used_ebs argument should contain total number of logical
689 * eraseblock in this static volume.
691 * When writing to the last logical eraseblock, the @len argument doesn't have
692 * to be aligned to the minimal I/O unit size. Instead, it has to be equivalent
693 * to the real data size, although the @buf buffer has to contain the
694 * alignment. In all other cases, @len has to be aligned.
696 * It is prohibited to write more then once to logical eraseblocks of static
697 * volumes. This function returns zero in case of success and a negative error
698 * code in case of failure.
700 int ubi_eba_write_leb_st(struct ubi_device
*ubi
, struct ubi_volume
*vol
,
701 int lnum
, const void *buf
, int len
, int dtype
,
704 int err
, pnum
, tries
= 0, data_size
= len
, vol_id
= vol
->vol_id
;
705 struct ubi_vid_hdr
*vid_hdr
;
711 if (lnum
== used_ebs
- 1)
712 /* If this is the last LEB @len may be unaligned */
713 len
= ALIGN(data_size
, ubi
->min_io_size
);
715 ubi_assert(len
% ubi
->min_io_size
== 0);
717 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
721 err
= leb_write_lock(ubi
, vol_id
, lnum
);
723 ubi_free_vid_hdr(ubi
, vid_hdr
);
727 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
728 vid_hdr
->vol_id
= cpu_to_be32(vol_id
);
729 vid_hdr
->lnum
= cpu_to_be32(lnum
);
730 vid_hdr
->compat
= ubi_get_compat(ubi
, vol_id
);
731 vid_hdr
->data_pad
= cpu_to_be32(vol
->data_pad
);
733 crc
= crc32(UBI_CRC32_INIT
, buf
, data_size
);
734 vid_hdr
->vol_type
= UBI_VID_STATIC
;
735 vid_hdr
->data_size
= cpu_to_be32(data_size
);
736 vid_hdr
->used_ebs
= cpu_to_be32(used_ebs
);
737 vid_hdr
->data_crc
= cpu_to_be32(crc
);
740 pnum
= ubi_wl_get_peb(ubi
, dtype
);
742 ubi_free_vid_hdr(ubi
, vid_hdr
);
743 leb_write_unlock(ubi
, vol_id
, lnum
);
747 dbg_eba("write VID hdr and %d bytes at LEB %d:%d, PEB %d, used_ebs %d",
748 len
, vol_id
, lnum
, pnum
, used_ebs
);
750 err
= ubi_io_write_vid_hdr(ubi
, pnum
, vid_hdr
);
752 ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
757 err
= ubi_io_write_data(ubi
, buf
, pnum
, 0, len
);
759 ubi_warn("failed to write %d bytes of data to PEB %d",
764 ubi_assert(vol
->eba_tbl
[lnum
] < 0);
765 vol
->eba_tbl
[lnum
] = pnum
;
767 leb_write_unlock(ubi
, vol_id
, lnum
);
768 ubi_free_vid_hdr(ubi
, vid_hdr
);
772 if (err
!= -EIO
|| !ubi
->bad_allowed
) {
774 * This flash device does not admit of bad eraseblocks or
775 * something nasty and unexpected happened. Switch to read-only
779 leb_write_unlock(ubi
, vol_id
, lnum
);
780 ubi_free_vid_hdr(ubi
, vid_hdr
);
784 err
= ubi_wl_put_peb(ubi
, pnum
, 1);
785 if (err
|| ++tries
> UBI_IO_RETRIES
) {
787 leb_write_unlock(ubi
, vol_id
, lnum
);
788 ubi_free_vid_hdr(ubi
, vid_hdr
);
792 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
793 ubi_msg("try another PEB");
798 * ubi_eba_atomic_leb_change - change logical eraseblock atomically.
799 * @ubi: UBI device description object
800 * @vol: volume description object
801 * @lnum: logical eraseblock number
802 * @buf: data to write
803 * @len: how many bytes to write
806 * This function changes the contents of a logical eraseblock atomically. @buf
807 * has to contain new logical eraseblock data, and @len - the length of the
808 * data, which has to be aligned. This function guarantees that in case of an
809 * unclean reboot the old contents is preserved. Returns zero in case of
810 * success and a negative error code in case of failure.
812 * UBI reserves one LEB for the "atomic LEB change" operation, so only one
813 * LEB change may be done at a time. This is ensured by @ubi->alc_mutex.
815 int ubi_eba_atomic_leb_change(struct ubi_device
*ubi
, struct ubi_volume
*vol
,
816 int lnum
, const void *buf
, int len
, int dtype
)
818 int err
, pnum
, tries
= 0, vol_id
= vol
->vol_id
;
819 struct ubi_vid_hdr
*vid_hdr
;
825 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
829 mutex_lock(&ubi
->alc_mutex
);
830 err
= leb_write_lock(ubi
, vol_id
, lnum
);
834 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
835 vid_hdr
->vol_id
= cpu_to_be32(vol_id
);
836 vid_hdr
->lnum
= cpu_to_be32(lnum
);
837 vid_hdr
->compat
= ubi_get_compat(ubi
, vol_id
);
838 vid_hdr
->data_pad
= cpu_to_be32(vol
->data_pad
);
840 crc
= crc32(UBI_CRC32_INIT
, buf
, len
);
841 vid_hdr
->vol_type
= UBI_VID_DYNAMIC
;
842 vid_hdr
->data_size
= cpu_to_be32(len
);
843 vid_hdr
->copy_flag
= 1;
844 vid_hdr
->data_crc
= cpu_to_be32(crc
);
847 pnum
= ubi_wl_get_peb(ubi
, dtype
);
853 dbg_eba("change LEB %d:%d, PEB %d, write VID hdr to PEB %d",
854 vol_id
, lnum
, vol
->eba_tbl
[lnum
], pnum
);
856 err
= ubi_io_write_vid_hdr(ubi
, pnum
, vid_hdr
);
858 ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
863 err
= ubi_io_write_data(ubi
, buf
, pnum
, 0, len
);
865 ubi_warn("failed to write %d bytes of data to PEB %d",
870 if (vol
->eba_tbl
[lnum
] >= 0) {
871 err
= ubi_wl_put_peb(ubi
, vol
->eba_tbl
[lnum
], 1);
876 vol
->eba_tbl
[lnum
] = pnum
;
879 leb_write_unlock(ubi
, vol_id
, lnum
);
881 mutex_unlock(&ubi
->alc_mutex
);
882 ubi_free_vid_hdr(ubi
, vid_hdr
);
886 if (err
!= -EIO
|| !ubi
->bad_allowed
) {
888 * This flash device does not admit of bad eraseblocks or
889 * something nasty and unexpected happened. Switch to read-only
896 err
= ubi_wl_put_peb(ubi
, pnum
, 1);
897 if (err
|| ++tries
> UBI_IO_RETRIES
) {
902 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
903 ubi_msg("try another PEB");
908 * ubi_eba_copy_leb - copy logical eraseblock.
909 * @ubi: UBI device description object
910 * @from: physical eraseblock number from where to copy
911 * @to: physical eraseblock number where to copy
912 * @vid_hdr: VID header of the @from physical eraseblock
914 * This function copies logical eraseblock from physical eraseblock @from to
915 * physical eraseblock @to. The @vid_hdr buffer may be changed by this
916 * function. Returns zero in case of success, %UBI_IO_BITFLIPS if the operation
917 * was canceled because bit-flips were detected at the target PEB, and a
918 * negative error code in case of failure.
920 int ubi_eba_copy_leb(struct ubi_device
*ubi
, int from
, int to
,
921 struct ubi_vid_hdr
*vid_hdr
)
923 int err
, vol_id
, lnum
, data_size
, aldata_size
, pnum
, idx
;
924 struct ubi_volume
*vol
;
927 vol_id
= be32_to_cpu(vid_hdr
->vol_id
);
928 lnum
= be32_to_cpu(vid_hdr
->lnum
);
930 dbg_eba("copy LEB %d:%d, PEB %d to PEB %d", vol_id
, lnum
, from
, to
);
932 if (vid_hdr
->vol_type
== UBI_VID_STATIC
) {
933 data_size
= be32_to_cpu(vid_hdr
->data_size
);
934 aldata_size
= ALIGN(data_size
, ubi
->min_io_size
);
936 data_size
= aldata_size
=
937 ubi
->leb_size
- be32_to_cpu(vid_hdr
->data_pad
);
940 * We do not want anybody to write to this logical eraseblock while we
941 * are moving it, so we lock it.
943 err
= leb_write_lock(ubi
, vol_id
, lnum
);
947 mutex_lock(&ubi
->buf_mutex
);
950 * But the logical eraseblock might have been put by this time.
951 * Cancel if it is true.
953 idx
= vol_id2idx(ubi
, vol_id
);
956 * We may race with volume deletion/re-size, so we have to hold
957 * @ubi->volumes_lock.
959 * Note, it is not a problem if we race with volume deletion or re-size
960 * here. If the volume is deleted or re-sized while we are moving an
961 * eraseblock which belongs to this volume, we'll end up with finding
962 * out that this LEB was unmapped at the end (see WL), and drop this
965 spin_lock(&ubi
->volumes_lock
);
966 vol
= ubi
->volumes
[idx
];
968 dbg_eba("volume %d was removed meanwhile", vol_id
);
969 spin_unlock(&ubi
->volumes_lock
);
973 pnum
= vol
->eba_tbl
[lnum
];
975 dbg_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to "
976 "PEB %d, cancel", vol_id
, lnum
, from
, pnum
);
977 spin_unlock(&ubi
->volumes_lock
);
980 spin_unlock(&ubi
->volumes_lock
);
982 /* OK, now the LEB is locked and we can safely start moving it */
984 dbg_eba("read %d bytes of data", aldata_size
);
985 err
= ubi_io_read_data(ubi
, ubi
->peb_buf1
, from
, 0, aldata_size
);
986 if (err
&& err
!= UBI_IO_BITFLIPS
) {
987 ubi_warn("error %d while reading data from PEB %d",
993 * Now we have got to calculate how much data we have to to copy. In
994 * case of a static volume it is fairly easy - the VID header contains
995 * the data size. In case of a dynamic volume it is more difficult - we
996 * have to read the contents, cut 0xFF bytes from the end and copy only
997 * the first part. We must do this to avoid writing 0xFF bytes as it
998 * may have some side-effects. And not only this. It is important not
999 * to include those 0xFFs to CRC because later the they may be filled
1002 if (vid_hdr
->vol_type
== UBI_VID_DYNAMIC
)
1003 aldata_size
= data_size
=
1004 ubi_calc_data_len(ubi
, ubi
->peb_buf1
, data_size
);
1007 crc
= crc32(UBI_CRC32_INIT
, ubi
->peb_buf1
, data_size
);
1011 * It may turn out to me that the whole @from physical eraseblock
1012 * contains only 0xFF bytes. Then we have to only write the VID header
1013 * and do not write any data. This also means we should not set
1014 * @vid_hdr->copy_flag, @vid_hdr->data_size, and @vid_hdr->data_crc.
1016 if (data_size
> 0) {
1017 vid_hdr
->copy_flag
= 1;
1018 vid_hdr
->data_size
= cpu_to_be32(data_size
);
1019 vid_hdr
->data_crc
= cpu_to_be32(crc
);
1021 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
1023 err
= ubi_io_write_vid_hdr(ubi
, to
, vid_hdr
);
1029 /* Read the VID header back and check if it was written correctly */
1030 err
= ubi_io_read_vid_hdr(ubi
, to
, vid_hdr
, 1);
1032 if (err
!= UBI_IO_BITFLIPS
)
1033 ubi_warn("cannot read VID header back from PEB %d", to
);
1037 if (data_size
> 0) {
1038 err
= ubi_io_write_data(ubi
, ubi
->peb_buf1
, to
, 0, aldata_size
);
1045 * We've written the data and are going to read it back to make
1046 * sure it was written correctly.
1049 err
= ubi_io_read_data(ubi
, ubi
->peb_buf2
, to
, 0, aldata_size
);
1051 if (err
!= UBI_IO_BITFLIPS
)
1052 ubi_warn("cannot read data back from PEB %d",
1059 if (memcmp(ubi
->peb_buf1
, ubi
->peb_buf2
, aldata_size
)) {
1060 ubi_warn("read data back from PEB %d - it is different",
1066 ubi_assert(vol
->eba_tbl
[lnum
] == from
);
1067 vol
->eba_tbl
[lnum
] = to
;
1070 mutex_unlock(&ubi
->buf_mutex
);
1071 leb_write_unlock(ubi
, vol_id
, lnum
);
1076 * ubi_eba_init_scan - initialize the EBA unit using scanning information.
1077 * @ubi: UBI device description object
1078 * @si: scanning information
1080 * This function returns zero in case of success and a negative error code in
1083 int ubi_eba_init_scan(struct ubi_device
*ubi
, struct ubi_scan_info
*si
)
1085 int i
, j
, err
, num_volumes
;
1086 struct ubi_scan_volume
*sv
;
1087 struct ubi_volume
*vol
;
1088 struct ubi_scan_leb
*seb
;
1091 dbg_eba("initialize EBA unit");
1093 spin_lock_init(&ubi
->ltree_lock
);
1094 mutex_init(&ubi
->alc_mutex
);
1095 ubi
->ltree
= RB_ROOT
;
1097 ubi
->global_sqnum
= si
->max_sqnum
+ 1;
1098 num_volumes
= ubi
->vtbl_slots
+ UBI_INT_VOL_COUNT
;
1100 for (i
= 0; i
< num_volumes
; i
++) {
1101 vol
= ubi
->volumes
[i
];
1107 vol
->eba_tbl
= kmalloc(vol
->reserved_pebs
* sizeof(int),
1109 if (!vol
->eba_tbl
) {
1114 for (j
= 0; j
< vol
->reserved_pebs
; j
++)
1115 vol
->eba_tbl
[j
] = UBI_LEB_UNMAPPED
;
1117 sv
= ubi_scan_find_sv(si
, idx2vol_id(ubi
, i
));
1121 ubi_rb_for_each_entry(rb
, seb
, &sv
->root
, u
.rb
) {
1122 if (seb
->lnum
>= vol
->reserved_pebs
)
1124 * This may happen in case of an unclean reboot
1127 ubi_scan_move_to_list(sv
, seb
, &si
->erase
);
1128 vol
->eba_tbl
[seb
->lnum
] = seb
->pnum
;
1132 if (ubi
->avail_pebs
< EBA_RESERVED_PEBS
) {
1133 ubi_err("no enough physical eraseblocks (%d, need %d)",
1134 ubi
->avail_pebs
, EBA_RESERVED_PEBS
);
1138 ubi
->avail_pebs
-= EBA_RESERVED_PEBS
;
1139 ubi
->rsvd_pebs
+= EBA_RESERVED_PEBS
;
1141 if (ubi
->bad_allowed
) {
1142 ubi_calculate_reserved(ubi
);
1144 if (ubi
->avail_pebs
< ubi
->beb_rsvd_level
) {
1145 /* No enough free physical eraseblocks */
1146 ubi
->beb_rsvd_pebs
= ubi
->avail_pebs
;
1147 ubi_warn("cannot reserve enough PEBs for bad PEB "
1148 "handling, reserved %d, need %d",
1149 ubi
->beb_rsvd_pebs
, ubi
->beb_rsvd_level
);
1151 ubi
->beb_rsvd_pebs
= ubi
->beb_rsvd_level
;
1153 ubi
->avail_pebs
-= ubi
->beb_rsvd_pebs
;
1154 ubi
->rsvd_pebs
+= ubi
->beb_rsvd_pebs
;
1157 dbg_eba("EBA unit is initialized");
1161 for (i
= 0; i
< num_volumes
; i
++) {
1162 if (!ubi
->volumes
[i
])
1164 kfree(ubi
->volumes
[i
]->eba_tbl
);
1170 * ubi_eba_close - close EBA unit.
1171 * @ubi: UBI device description object
1173 void ubi_eba_close(const struct ubi_device
*ubi
)
1175 int i
, num_volumes
= ubi
->vtbl_slots
+ UBI_INT_VOL_COUNT
;
1177 dbg_eba("close EBA unit");
1179 for (i
= 0; i
< num_volumes
; i
++) {
1180 if (!ubi
->volumes
[i
])
1182 kfree(ubi
->volumes
[i
]->eba_tbl
);
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