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(ubi
->ref_count
> 0);
343 ubi_assert(vol
->ref_count
> 0);
348 err
= leb_write_lock(ubi
, vol_id
, lnum
);
352 pnum
= vol
->eba_tbl
[lnum
];
354 /* This logical eraseblock is already unmapped */
357 dbg_eba("erase LEB %d:%d, PEB %d", vol_id
, lnum
, pnum
);
359 vol
->eba_tbl
[lnum
] = UBI_LEB_UNMAPPED
;
360 err
= ubi_wl_put_peb(ubi
, pnum
, 0);
363 leb_write_unlock(ubi
, vol_id
, lnum
);
368 * ubi_eba_read_leb - read data.
369 * @ubi: UBI device description object
370 * @vol: volume description object
371 * @lnum: logical eraseblock number
372 * @buf: buffer to store the read data
373 * @offset: offset from where to read
374 * @len: how many bytes to read
375 * @check: data CRC check flag
377 * If the logical eraseblock @lnum is unmapped, @buf is filled with 0xFF
378 * bytes. The @check flag only makes sense for static volumes and forces
379 * eraseblock data CRC checking.
381 * In case of success this function returns zero. In case of a static volume,
382 * if data CRC mismatches - %-EBADMSG is returned. %-EBADMSG may also be
383 * returned for any volume type if an ECC error was detected by the MTD device
384 * driver. Other negative error cored may be returned in case of other errors.
386 int ubi_eba_read_leb(struct ubi_device
*ubi
, struct ubi_volume
*vol
, int lnum
,
387 void *buf
, int offset
, int len
, int check
)
389 int err
, pnum
, scrub
= 0, vol_id
= vol
->vol_id
;
390 struct ubi_vid_hdr
*vid_hdr
;
391 uint32_t uninitialized_var(crc
);
393 ubi_assert(ubi
->ref_count
> 0);
394 ubi_assert(vol
->ref_count
> 0);
396 err
= leb_read_lock(ubi
, vol_id
, lnum
);
400 pnum
= vol
->eba_tbl
[lnum
];
403 * The logical eraseblock is not mapped, fill the whole buffer
404 * with 0xFF bytes. The exception is static volumes for which
405 * it is an error to read unmapped logical eraseblocks.
407 dbg_eba("read %d bytes from offset %d of LEB %d:%d (unmapped)",
408 len
, offset
, vol_id
, lnum
);
409 leb_read_unlock(ubi
, vol_id
, lnum
);
410 ubi_assert(vol
->vol_type
!= UBI_STATIC_VOLUME
);
411 memset(buf
, 0xFF, len
);
415 dbg_eba("read %d bytes from offset %d of LEB %d:%d, PEB %d",
416 len
, offset
, vol_id
, lnum
, pnum
);
418 if (vol
->vol_type
== UBI_DYNAMIC_VOLUME
)
423 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
429 err
= ubi_io_read_vid_hdr(ubi
, pnum
, vid_hdr
, 1);
430 if (err
&& err
!= UBI_IO_BITFLIPS
) {
433 * The header is either absent or corrupted.
434 * The former case means there is a bug -
435 * switch to read-only mode just in case.
436 * The latter case means a real corruption - we
437 * may try to recover data. FIXME: but this is
440 if (err
== UBI_IO_BAD_VID_HDR
) {
441 ubi_warn("bad VID header at PEB %d, LEB"
442 "%d:%d", pnum
, vol_id
, lnum
);
448 } else if (err
== UBI_IO_BITFLIPS
)
451 ubi_assert(lnum
< be32_to_cpu(vid_hdr
->used_ebs
));
452 ubi_assert(len
== be32_to_cpu(vid_hdr
->data_size
));
454 crc
= be32_to_cpu(vid_hdr
->data_crc
);
455 ubi_free_vid_hdr(ubi
, vid_hdr
);
458 err
= ubi_io_read_data(ubi
, buf
, pnum
, offset
, len
);
460 if (err
== UBI_IO_BITFLIPS
) {
463 } else if (err
== -EBADMSG
) {
464 if (vol
->vol_type
== UBI_DYNAMIC_VOLUME
)
468 ubi_msg("force data checking");
477 uint32_t crc1
= crc32(UBI_CRC32_INIT
, buf
, len
);
479 ubi_warn("CRC error: calculated %#08x, must be %#08x",
487 err
= ubi_wl_scrub_peb(ubi
, pnum
);
489 leb_read_unlock(ubi
, vol_id
, lnum
);
493 ubi_free_vid_hdr(ubi
, vid_hdr
);
495 leb_read_unlock(ubi
, vol_id
, lnum
);
500 * recover_peb - recover from write failure.
501 * @ubi: UBI device description object
502 * @pnum: the physical eraseblock to recover
504 * @lnum: logical eraseblock number
505 * @buf: data which was not written because of the write failure
506 * @offset: offset of the failed write
507 * @len: how many bytes should have been written
509 * This function is called in case of a write failure and moves all good data
510 * from the potentially bad physical eraseblock to a good physical eraseblock.
511 * This function also writes the data which was not written due to the failure.
512 * Returns new physical eraseblock number in case of success, and a negative
513 * error code in case of failure.
515 static int recover_peb(struct ubi_device
*ubi
, int pnum
, int vol_id
, int lnum
,
516 const void *buf
, int offset
, int len
)
518 int err
, idx
= vol_id2idx(ubi
, vol_id
), new_pnum
, data_size
, tries
= 0;
519 struct ubi_volume
*vol
= ubi
->volumes
[idx
];
520 struct ubi_vid_hdr
*vid_hdr
;
522 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
527 mutex_lock(&ubi
->buf_mutex
);
530 new_pnum
= ubi_wl_get_peb(ubi
, UBI_UNKNOWN
);
532 mutex_unlock(&ubi
->buf_mutex
);
533 ubi_free_vid_hdr(ubi
, vid_hdr
);
537 ubi_msg("recover PEB %d, move data to PEB %d", pnum
, new_pnum
);
539 err
= ubi_io_read_vid_hdr(ubi
, pnum
, vid_hdr
, 1);
540 if (err
&& err
!= UBI_IO_BITFLIPS
) {
546 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
547 err
= ubi_io_write_vid_hdr(ubi
, new_pnum
, vid_hdr
);
551 data_size
= offset
+ len
;
552 memset(ubi
->peb_buf1
+ offset
, 0xFF, len
);
554 /* Read everything before the area where the write failure happened */
556 err
= ubi_io_read_data(ubi
, ubi
->peb_buf1
, pnum
, 0, offset
);
557 if (err
&& err
!= UBI_IO_BITFLIPS
)
561 memcpy(ubi
->peb_buf1
+ offset
, buf
, len
);
563 err
= ubi_io_write_data(ubi
, ubi
->peb_buf1
, new_pnum
, 0, data_size
);
567 mutex_unlock(&ubi
->buf_mutex
);
568 ubi_free_vid_hdr(ubi
, vid_hdr
);
570 vol
->eba_tbl
[lnum
] = new_pnum
;
571 ubi_wl_put_peb(ubi
, pnum
, 1);
573 ubi_msg("data was successfully recovered");
577 mutex_unlock(&ubi
->buf_mutex
);
578 ubi_wl_put_peb(ubi
, new_pnum
, 1);
579 ubi_free_vid_hdr(ubi
, vid_hdr
);
584 * Bad luck? This physical eraseblock is bad too? Crud. Let's try to
587 ubi_warn("failed to write to PEB %d", new_pnum
);
588 ubi_wl_put_peb(ubi
, new_pnum
, 1);
589 if (++tries
> UBI_IO_RETRIES
) {
590 mutex_unlock(&ubi
->buf_mutex
);
591 ubi_free_vid_hdr(ubi
, vid_hdr
);
594 ubi_msg("try again");
599 * ubi_eba_write_leb - write data to dynamic volume.
600 * @ubi: UBI device description object
601 * @vol: volume description object
602 * @lnum: logical eraseblock number
603 * @buf: the data to write
604 * @offset: offset within the logical eraseblock where to write
605 * @len: how many bytes to write
608 * This function writes data to logical eraseblock @lnum of a dynamic volume
609 * @vol. Returns zero in case of success and a negative error code in case
610 * of failure. In case of error, it is possible that something was still
611 * written to the flash media, but may be some garbage.
613 int ubi_eba_write_leb(struct ubi_device
*ubi
, struct ubi_volume
*vol
, int lnum
,
614 const void *buf
, int offset
, int len
, int dtype
)
616 int err
, pnum
, tries
= 0, vol_id
= vol
->vol_id
;
617 struct ubi_vid_hdr
*vid_hdr
;
619 ubi_assert(ubi
->ref_count
> 0);
620 ubi_assert(vol
->ref_count
> 0);
625 err
= leb_write_lock(ubi
, vol_id
, lnum
);
629 pnum
= vol
->eba_tbl
[lnum
];
631 dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d",
632 len
, offset
, vol_id
, lnum
, pnum
);
634 err
= ubi_io_write_data(ubi
, buf
, pnum
, offset
, len
);
636 ubi_warn("failed to write data to PEB %d", pnum
);
637 if (err
== -EIO
&& ubi
->bad_allowed
)
638 err
= recover_peb(ubi
, pnum
, vol_id
, lnum
, buf
,
643 leb_write_unlock(ubi
, vol_id
, lnum
);
648 * The logical eraseblock is not mapped. We have to get a free physical
649 * eraseblock and write the volume identifier header there first.
651 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
653 leb_write_unlock(ubi
, vol_id
, lnum
);
657 vid_hdr
->vol_type
= UBI_VID_DYNAMIC
;
658 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
659 vid_hdr
->vol_id
= cpu_to_be32(vol_id
);
660 vid_hdr
->lnum
= cpu_to_be32(lnum
);
661 vid_hdr
->compat
= ubi_get_compat(ubi
, vol_id
);
662 vid_hdr
->data_pad
= cpu_to_be32(vol
->data_pad
);
665 pnum
= ubi_wl_get_peb(ubi
, dtype
);
667 ubi_free_vid_hdr(ubi
, vid_hdr
);
668 leb_write_unlock(ubi
, vol_id
, lnum
);
672 dbg_eba("write VID hdr and %d bytes at offset %d of LEB %d:%d, PEB %d",
673 len
, offset
, vol_id
, lnum
, pnum
);
675 err
= ubi_io_write_vid_hdr(ubi
, pnum
, vid_hdr
);
677 ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
683 err
= ubi_io_write_data(ubi
, buf
, pnum
, offset
, len
);
685 ubi_warn("failed to write %d bytes at offset %d of "
686 "LEB %d:%d, PEB %d", len
, offset
, vol_id
,
692 vol
->eba_tbl
[lnum
] = pnum
;
694 leb_write_unlock(ubi
, vol_id
, lnum
);
695 ubi_free_vid_hdr(ubi
, vid_hdr
);
699 if (err
!= -EIO
|| !ubi
->bad_allowed
) {
701 leb_write_unlock(ubi
, vol_id
, lnum
);
702 ubi_free_vid_hdr(ubi
, vid_hdr
);
707 * Fortunately, this is the first write operation to this physical
708 * eraseblock, so just put it and request a new one. We assume that if
709 * this physical eraseblock went bad, the erase code will handle that.
711 err
= ubi_wl_put_peb(ubi
, pnum
, 1);
712 if (err
|| ++tries
> UBI_IO_RETRIES
) {
714 leb_write_unlock(ubi
, vol_id
, lnum
);
715 ubi_free_vid_hdr(ubi
, vid_hdr
);
719 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
720 ubi_msg("try another PEB");
725 * ubi_eba_write_leb_st - write data to static volume.
726 * @ubi: UBI device description object
727 * @vol: volume description object
728 * @lnum: logical eraseblock number
729 * @buf: data to write
730 * @len: how many bytes to write
732 * @used_ebs: how many logical eraseblocks will this volume contain
734 * This function writes data to logical eraseblock @lnum of static volume
735 * @vol. The @used_ebs argument should contain total number of logical
736 * eraseblock in this static volume.
738 * When writing to the last logical eraseblock, the @len argument doesn't have
739 * to be aligned to the minimal I/O unit size. Instead, it has to be equivalent
740 * to the real data size, although the @buf buffer has to contain the
741 * alignment. In all other cases, @len has to be aligned.
743 * It is prohibited to write more then once to logical eraseblocks of static
744 * volumes. This function returns zero in case of success and a negative error
745 * code in case of failure.
747 int ubi_eba_write_leb_st(struct ubi_device
*ubi
, struct ubi_volume
*vol
,
748 int lnum
, const void *buf
, int len
, int dtype
,
751 int err
, pnum
, tries
= 0, data_size
= len
, vol_id
= vol
->vol_id
;
752 struct ubi_vid_hdr
*vid_hdr
;
755 ubi_assert(ubi
->ref_count
> 0);
756 ubi_assert(vol
->ref_count
> 0);
761 if (lnum
== used_ebs
- 1)
762 /* If this is the last LEB @len may be unaligned */
763 len
= ALIGN(data_size
, ubi
->min_io_size
);
765 ubi_assert(len
% ubi
->min_io_size
== 0);
767 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
771 err
= leb_write_lock(ubi
, vol_id
, lnum
);
773 ubi_free_vid_hdr(ubi
, vid_hdr
);
777 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
778 vid_hdr
->vol_id
= cpu_to_be32(vol_id
);
779 vid_hdr
->lnum
= cpu_to_be32(lnum
);
780 vid_hdr
->compat
= ubi_get_compat(ubi
, vol_id
);
781 vid_hdr
->data_pad
= cpu_to_be32(vol
->data_pad
);
783 crc
= crc32(UBI_CRC32_INIT
, buf
, data_size
);
784 vid_hdr
->vol_type
= UBI_VID_STATIC
;
785 vid_hdr
->data_size
= cpu_to_be32(data_size
);
786 vid_hdr
->used_ebs
= cpu_to_be32(used_ebs
);
787 vid_hdr
->data_crc
= cpu_to_be32(crc
);
790 pnum
= ubi_wl_get_peb(ubi
, dtype
);
792 ubi_free_vid_hdr(ubi
, vid_hdr
);
793 leb_write_unlock(ubi
, vol_id
, lnum
);
797 dbg_eba("write VID hdr and %d bytes at LEB %d:%d, PEB %d, used_ebs %d",
798 len
, vol_id
, lnum
, pnum
, used_ebs
);
800 err
= ubi_io_write_vid_hdr(ubi
, pnum
, vid_hdr
);
802 ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
807 err
= ubi_io_write_data(ubi
, buf
, pnum
, 0, len
);
809 ubi_warn("failed to write %d bytes of data to PEB %d",
814 ubi_assert(vol
->eba_tbl
[lnum
] < 0);
815 vol
->eba_tbl
[lnum
] = pnum
;
817 leb_write_unlock(ubi
, vol_id
, lnum
);
818 ubi_free_vid_hdr(ubi
, vid_hdr
);
822 if (err
!= -EIO
|| !ubi
->bad_allowed
) {
824 * This flash device does not admit of bad eraseblocks or
825 * something nasty and unexpected happened. Switch to read-only
829 leb_write_unlock(ubi
, vol_id
, lnum
);
830 ubi_free_vid_hdr(ubi
, vid_hdr
);
834 err
= ubi_wl_put_peb(ubi
, pnum
, 1);
835 if (err
|| ++tries
> UBI_IO_RETRIES
) {
837 leb_write_unlock(ubi
, vol_id
, lnum
);
838 ubi_free_vid_hdr(ubi
, vid_hdr
);
842 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
843 ubi_msg("try another PEB");
848 * ubi_eba_atomic_leb_change - change logical eraseblock atomically.
849 * @ubi: UBI device description object
850 * @vol: volume description object
851 * @lnum: logical eraseblock number
852 * @buf: data to write
853 * @len: how many bytes to write
856 * This function changes the contents of a logical eraseblock atomically. @buf
857 * has to contain new logical eraseblock data, and @len - the length of the
858 * data, which has to be aligned. This function guarantees that in case of an
859 * unclean reboot the old contents is preserved. Returns zero in case of
860 * success and a negative error code in case of failure.
862 * UBI reserves one LEB for the "atomic LEB change" operation, so only one
863 * LEB change may be done at a time. This is ensured by @ubi->alc_mutex.
865 int ubi_eba_atomic_leb_change(struct ubi_device
*ubi
, struct ubi_volume
*vol
,
866 int lnum
, const void *buf
, int len
, int dtype
)
868 int err
, pnum
, tries
= 0, vol_id
= vol
->vol_id
;
869 struct ubi_vid_hdr
*vid_hdr
;
872 ubi_assert(ubi
->ref_count
> 0);
873 ubi_assert(vol
->ref_count
> 0);
878 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
882 mutex_lock(&ubi
->alc_mutex
);
883 err
= leb_write_lock(ubi
, vol_id
, lnum
);
887 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
888 vid_hdr
->vol_id
= cpu_to_be32(vol_id
);
889 vid_hdr
->lnum
= cpu_to_be32(lnum
);
890 vid_hdr
->compat
= ubi_get_compat(ubi
, vol_id
);
891 vid_hdr
->data_pad
= cpu_to_be32(vol
->data_pad
);
893 crc
= crc32(UBI_CRC32_INIT
, buf
, len
);
894 vid_hdr
->vol_type
= UBI_VID_DYNAMIC
;
895 vid_hdr
->data_size
= cpu_to_be32(len
);
896 vid_hdr
->copy_flag
= 1;
897 vid_hdr
->data_crc
= cpu_to_be32(crc
);
900 pnum
= ubi_wl_get_peb(ubi
, dtype
);
906 dbg_eba("change LEB %d:%d, PEB %d, write VID hdr to PEB %d",
907 vol_id
, lnum
, vol
->eba_tbl
[lnum
], pnum
);
909 err
= ubi_io_write_vid_hdr(ubi
, pnum
, vid_hdr
);
911 ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
916 err
= ubi_io_write_data(ubi
, buf
, pnum
, 0, len
);
918 ubi_warn("failed to write %d bytes of data to PEB %d",
923 if (vol
->eba_tbl
[lnum
] >= 0) {
924 err
= ubi_wl_put_peb(ubi
, vol
->eba_tbl
[lnum
], 1);
929 vol
->eba_tbl
[lnum
] = pnum
;
932 leb_write_unlock(ubi
, vol_id
, lnum
);
934 mutex_unlock(&ubi
->alc_mutex
);
935 ubi_free_vid_hdr(ubi
, vid_hdr
);
939 if (err
!= -EIO
|| !ubi
->bad_allowed
) {
941 * This flash device does not admit of bad eraseblocks or
942 * something nasty and unexpected happened. Switch to read-only
949 err
= ubi_wl_put_peb(ubi
, pnum
, 1);
950 if (err
|| ++tries
> UBI_IO_RETRIES
) {
955 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
956 ubi_msg("try another PEB");
961 * ubi_eba_copy_leb - copy logical eraseblock.
962 * @ubi: UBI device description object
963 * @from: physical eraseblock number from where to copy
964 * @to: physical eraseblock number where to copy
965 * @vid_hdr: VID header of the @from physical eraseblock
967 * This function copies logical eraseblock from physical eraseblock @from to
968 * physical eraseblock @to. The @vid_hdr buffer may be changed by this
970 * o %0 in case of success;
971 * o %1 if the operation was canceled and should be tried later (e.g.,
972 * because a bit-flip was detected at the target PEB);
973 * o %2 if the volume is being deleted and this LEB should not be moved.
975 int ubi_eba_copy_leb(struct ubi_device
*ubi
, int from
, int to
,
976 struct ubi_vid_hdr
*vid_hdr
)
978 int err
, vol_id
, lnum
, data_size
, aldata_size
, idx
;
979 struct ubi_volume
*vol
;
982 vol_id
= be32_to_cpu(vid_hdr
->vol_id
);
983 lnum
= be32_to_cpu(vid_hdr
->lnum
);
985 dbg_eba("copy LEB %d:%d, PEB %d to PEB %d", vol_id
, lnum
, from
, to
);
987 if (vid_hdr
->vol_type
== UBI_VID_STATIC
) {
988 data_size
= be32_to_cpu(vid_hdr
->data_size
);
989 aldata_size
= ALIGN(data_size
, ubi
->min_io_size
);
991 data_size
= aldata_size
=
992 ubi
->leb_size
- be32_to_cpu(vid_hdr
->data_pad
);
994 idx
= vol_id2idx(ubi
, vol_id
);
995 spin_lock(&ubi
->volumes_lock
);
997 * Note, we may race with volume deletion, which means that the volume
998 * this logical eraseblock belongs to might be being deleted. Since the
999 * volume deletion unmaps all the volume's logical eraseblocks, it will
1000 * be locked in 'ubi_wl_put_peb()' and wait for the WL worker to finish.
1002 vol
= ubi
->volumes
[idx
];
1004 /* No need to do further work, cancel */
1005 dbg_eba("volume %d is being removed, cancel", vol_id
);
1006 spin_unlock(&ubi
->volumes_lock
);
1009 spin_unlock(&ubi
->volumes_lock
);
1012 * We do not want anybody to write to this logical eraseblock while we
1013 * are moving it, so lock it.
1015 * Note, we are using non-waiting locking here, because we cannot sleep
1016 * on the LEB, since it may cause deadlocks. Indeed, imagine a task is
1017 * unmapping the LEB which is mapped to the PEB we are going to move
1018 * (@from). This task locks the LEB and goes sleep in the
1019 * 'ubi_wl_put_peb()' function on the @ubi->move_mutex. In turn, we are
1020 * holding @ubi->move_mutex and go sleep on the LEB lock. So, if the
1021 * LEB is already locked, we just do not move it and return %1.
1023 err
= leb_write_trylock(ubi
, vol_id
, lnum
);
1025 dbg_eba("contention on LEB %d:%d, cancel", vol_id
, lnum
);
1030 * The LEB might have been put meanwhile, and the task which put it is
1031 * probably waiting on @ubi->move_mutex. No need to continue the work,
1034 if (vol
->eba_tbl
[lnum
] != from
) {
1035 dbg_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to "
1036 "PEB %d, cancel", vol_id
, lnum
, from
,
1037 vol
->eba_tbl
[lnum
]);
1039 goto out_unlock_leb
;
1043 * OK, now the LEB is locked and we can safely start moving iy. Since
1044 * this function utilizes thie @ubi->peb1_buf buffer which is shared
1045 * with some other functions, so lock the buffer by taking the
1048 mutex_lock(&ubi
->buf_mutex
);
1049 dbg_eba("read %d bytes of data", aldata_size
);
1050 err
= ubi_io_read_data(ubi
, ubi
->peb_buf1
, from
, 0, aldata_size
);
1051 if (err
&& err
!= UBI_IO_BITFLIPS
) {
1052 ubi_warn("error %d while reading data from PEB %d",
1054 goto out_unlock_buf
;
1058 * Now we have got to calculate how much data we have to to copy. In
1059 * case of a static volume it is fairly easy - the VID header contains
1060 * the data size. In case of a dynamic volume it is more difficult - we
1061 * have to read the contents, cut 0xFF bytes from the end and copy only
1062 * the first part. We must do this to avoid writing 0xFF bytes as it
1063 * may have some side-effects. And not only this. It is important not
1064 * to include those 0xFFs to CRC because later the they may be filled
1067 if (vid_hdr
->vol_type
== UBI_VID_DYNAMIC
)
1068 aldata_size
= data_size
=
1069 ubi_calc_data_len(ubi
, ubi
->peb_buf1
, data_size
);
1072 crc
= crc32(UBI_CRC32_INIT
, ubi
->peb_buf1
, data_size
);
1076 * It may turn out to me that the whole @from physical eraseblock
1077 * contains only 0xFF bytes. Then we have to only write the VID header
1078 * and do not write any data. This also means we should not set
1079 * @vid_hdr->copy_flag, @vid_hdr->data_size, and @vid_hdr->data_crc.
1081 if (data_size
> 0) {
1082 vid_hdr
->copy_flag
= 1;
1083 vid_hdr
->data_size
= cpu_to_be32(data_size
);
1084 vid_hdr
->data_crc
= cpu_to_be32(crc
);
1086 vid_hdr
->sqnum
= cpu_to_be64(next_sqnum(ubi
));
1088 err
= ubi_io_write_vid_hdr(ubi
, to
, vid_hdr
);
1090 goto out_unlock_buf
;
1094 /* Read the VID header back and check if it was written correctly */
1095 err
= ubi_io_read_vid_hdr(ubi
, to
, vid_hdr
, 1);
1097 if (err
!= UBI_IO_BITFLIPS
)
1098 ubi_warn("cannot read VID header back from PEB %d", to
);
1101 goto out_unlock_buf
;
1104 if (data_size
> 0) {
1105 err
= ubi_io_write_data(ubi
, ubi
->peb_buf1
, to
, 0, aldata_size
);
1107 goto out_unlock_buf
;
1112 * We've written the data and are going to read it back to make
1113 * sure it was written correctly.
1116 err
= ubi_io_read_data(ubi
, ubi
->peb_buf2
, to
, 0, aldata_size
);
1118 if (err
!= UBI_IO_BITFLIPS
)
1119 ubi_warn("cannot read data back from PEB %d",
1123 goto out_unlock_buf
;
1128 if (memcmp(ubi
->peb_buf1
, ubi
->peb_buf2
, aldata_size
)) {
1129 ubi_warn("read data back from PEB %d - it is different",
1131 goto out_unlock_buf
;
1135 ubi_assert(vol
->eba_tbl
[lnum
] == from
);
1136 vol
->eba_tbl
[lnum
] = to
;
1139 mutex_unlock(&ubi
->buf_mutex
);
1141 leb_write_unlock(ubi
, vol_id
, lnum
);
1146 * ubi_eba_init_scan - initialize the EBA unit using scanning information.
1147 * @ubi: UBI device description object
1148 * @si: scanning information
1150 * This function returns zero in case of success and a negative error code in
1153 int ubi_eba_init_scan(struct ubi_device
*ubi
, struct ubi_scan_info
*si
)
1155 int i
, j
, err
, num_volumes
;
1156 struct ubi_scan_volume
*sv
;
1157 struct ubi_volume
*vol
;
1158 struct ubi_scan_leb
*seb
;
1161 dbg_eba("initialize EBA unit");
1163 spin_lock_init(&ubi
->ltree_lock
);
1164 mutex_init(&ubi
->alc_mutex
);
1165 ubi
->ltree
= RB_ROOT
;
1167 ubi
->global_sqnum
= si
->max_sqnum
+ 1;
1168 num_volumes
= ubi
->vtbl_slots
+ UBI_INT_VOL_COUNT
;
1170 for (i
= 0; i
< num_volumes
; i
++) {
1171 vol
= ubi
->volumes
[i
];
1177 vol
->eba_tbl
= kmalloc(vol
->reserved_pebs
* sizeof(int),
1179 if (!vol
->eba_tbl
) {
1184 for (j
= 0; j
< vol
->reserved_pebs
; j
++)
1185 vol
->eba_tbl
[j
] = UBI_LEB_UNMAPPED
;
1187 sv
= ubi_scan_find_sv(si
, idx2vol_id(ubi
, i
));
1191 ubi_rb_for_each_entry(rb
, seb
, &sv
->root
, u
.rb
) {
1192 if (seb
->lnum
>= vol
->reserved_pebs
)
1194 * This may happen in case of an unclean reboot
1197 ubi_scan_move_to_list(sv
, seb
, &si
->erase
);
1198 vol
->eba_tbl
[seb
->lnum
] = seb
->pnum
;
1202 if (ubi
->avail_pebs
< EBA_RESERVED_PEBS
) {
1203 ubi_err("no enough physical eraseblocks (%d, need %d)",
1204 ubi
->avail_pebs
, EBA_RESERVED_PEBS
);
1208 ubi
->avail_pebs
-= EBA_RESERVED_PEBS
;
1209 ubi
->rsvd_pebs
+= EBA_RESERVED_PEBS
;
1211 if (ubi
->bad_allowed
) {
1212 ubi_calculate_reserved(ubi
);
1214 if (ubi
->avail_pebs
< ubi
->beb_rsvd_level
) {
1215 /* No enough free physical eraseblocks */
1216 ubi
->beb_rsvd_pebs
= ubi
->avail_pebs
;
1217 ubi_warn("cannot reserve enough PEBs for bad PEB "
1218 "handling, reserved %d, need %d",
1219 ubi
->beb_rsvd_pebs
, ubi
->beb_rsvd_level
);
1221 ubi
->beb_rsvd_pebs
= ubi
->beb_rsvd_level
;
1223 ubi
->avail_pebs
-= ubi
->beb_rsvd_pebs
;
1224 ubi
->rsvd_pebs
+= ubi
->beb_rsvd_pebs
;
1227 dbg_eba("EBA unit is initialized");
1231 for (i
= 0; i
< num_volumes
; i
++) {
1232 if (!ubi
->volumes
[i
])
1234 kfree(ubi
->volumes
[i
]->eba_tbl
);
1240 * ubi_eba_close - close EBA unit.
1241 * @ubi: UBI device description object
1243 void ubi_eba_close(const struct ubi_device
*ubi
)
1245 int i
, num_volumes
= ubi
->vtbl_slots
+ UBI_INT_VOL_COUNT
;
1247 dbg_eba("close EBA unit");
1249 for (i
= 0; i
< num_volumes
; i
++) {
1250 if (!ubi
->volumes
[i
])
1252 kfree(ubi
->volumes
[i
]->eba_tbl
);
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