]>
git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - drivers/mtd/ubi/eba.c
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) sub-system.
24 * This sub-system 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 sub-system implements per-logical eraseblock locking. Before
31 * accessing a logical eraseblock it is locked for reading or writing. The
32 * per-logical eraseblock locking is implemented by means of the lock tree. The
33 * lock tree is an RB-tree which refers all the currently locked logical
34 * eraseblocks. The lock tree elements are &struct ubi_ltree_entry objects.
35 * They are indexed by (@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 unsigned long long ubi_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_VOLUME_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
= kmalloc(sizeof(struct ubi_ltree_entry
), GFP_NOFS
);
142 return ERR_PTR(-ENOMEM
);
145 init_rwsem(&le
->mutex
);
149 spin_lock(&ubi
->ltree_lock
);
150 le1
= ltree_lookup(ubi
, vol_id
, lnum
);
154 * This logical eraseblock is already locked. The newly
155 * allocated lock entry is not needed.
160 struct rb_node
**p
, *parent
= NULL
;
163 * No lock entry, add the newly allocated one to the
164 * @ubi->ltree RB-tree.
168 p
= &ubi
->ltree
.rb_node
;
171 le1
= rb_entry(parent
, struct ubi_ltree_entry
, rb
);
173 if (vol_id
< le1
->vol_id
)
175 else if (vol_id
> le1
->vol_id
)
178 ubi_assert(lnum
!= le1
->lnum
);
179 if (lnum
< le1
->lnum
)
186 rb_link_node(&le
->rb
, parent
, p
);
187 rb_insert_color(&le
->rb
, &ubi
->ltree
);
190 spin_unlock(&ubi
->ltree_lock
);
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
)
224 struct ubi_ltree_entry
*le
;
226 spin_lock(&ubi
->ltree_lock
);
227 le
= ltree_lookup(ubi
, vol_id
, lnum
);
229 ubi_assert(le
->users
>= 0);
231 if (le
->users
== 0) {
232 rb_erase(&le
->rb
, &ubi
->ltree
);
235 spin_unlock(&ubi
->ltree_lock
);
239 * leb_write_lock - lock logical eraseblock for writing.
240 * @ubi: UBI device description object
242 * @lnum: logical eraseblock number
244 * This function locks a logical eraseblock for writing. Returns zero in case
245 * of success and a negative error code in case of failure.
247 static int leb_write_lock(struct ubi_device
*ubi
, int vol_id
, int lnum
)
249 struct ubi_ltree_entry
*le
;
251 le
= ltree_add_entry(ubi
, vol_id
, lnum
);
254 down_write(&le
->mutex
);
259 * leb_write_lock - lock logical eraseblock for writing.
260 * @ubi: UBI device description object
262 * @lnum: logical eraseblock number
264 * This function locks a logical eraseblock for writing if there is no
265 * contention and does nothing if there is contention. Returns %0 in case of
266 * success, %1 in case of contention, and and a negative error code in case of
269 static int leb_write_trylock(struct ubi_device
*ubi
, int vol_id
, int lnum
)
271 struct ubi_ltree_entry
*le
;
273 le
= ltree_add_entry(ubi
, vol_id
, lnum
);
276 if (down_write_trylock(&le
->mutex
))
279 /* Contention, cancel */
280 spin_lock(&ubi
->ltree_lock
);
282 ubi_assert(le
->users
>= 0);
283 if (le
->users
== 0) {
284 rb_erase(&le
->rb
, &ubi
->ltree
);
287 spin_unlock(&ubi
->ltree_lock
);
293 * leb_write_unlock - unlock logical eraseblock.
294 * @ubi: UBI device description object
296 * @lnum: logical eraseblock number
298 static void leb_write_unlock(struct ubi_device
*ubi
, int vol_id
, int lnum
)
300 struct ubi_ltree_entry
*le
;
302 spin_lock(&ubi
->ltree_lock
);
303 le
= ltree_lookup(ubi
, vol_id
, lnum
);
305 ubi_assert(le
->users
>= 0);
306 up_write(&le
->mutex
);
307 if (le
->users
== 0) {
308 rb_erase(&le
->rb
, &ubi
->ltree
);
311 spin_unlock(&ubi
->ltree_lock
);
315 * ubi_eba_unmap_leb - un-map logical eraseblock.
316 * @ubi: UBI device description object
317 * @vol: volume description object
318 * @lnum: logical eraseblock number
320 * This function un-maps logical eraseblock @lnum and schedules corresponding
321 * physical eraseblock for erasure. Returns zero in case of success and a
322 * negative error code in case of failure.
324 int ubi_eba_unmap_leb(struct ubi_device
*ubi
, struct ubi_volume
*vol
,
327 int err
, pnum
, vol_id
= vol
->vol_id
;
332 err
= leb_write_lock(ubi
, vol_id
, lnum
);
336 pnum
= vol
->eba_tbl
[lnum
];
338 /* This logical eraseblock is already unmapped */
341 dbg_eba("erase LEB %d:%d, PEB %d", vol_id
, lnum
, pnum
);
343 down_read(&ubi
->fm_sem
);
344 vol
->eba_tbl
[lnum
] = UBI_LEB_UNMAPPED
;
345 up_read(&ubi
->fm_sem
);
346 err
= ubi_wl_put_peb(ubi
, vol_id
, lnum
, pnum
, 0);
349 leb_write_unlock(ubi
, vol_id
, lnum
);
354 * ubi_eba_read_leb - read data.
355 * @ubi: UBI device description object
356 * @vol: volume description object
357 * @lnum: logical eraseblock number
358 * @buf: buffer to store the read data
359 * @offset: offset from where to read
360 * @len: how many bytes to read
361 * @check: data CRC check flag
363 * If the logical eraseblock @lnum is unmapped, @buf is filled with 0xFF
364 * bytes. The @check flag only makes sense for static volumes and forces
365 * eraseblock data CRC checking.
367 * In case of success this function returns zero. In case of a static volume,
368 * if data CRC mismatches - %-EBADMSG is returned. %-EBADMSG may also be
369 * returned for any volume type if an ECC error was detected by the MTD device
370 * driver. Other negative error cored may be returned in case of other errors.
372 int ubi_eba_read_leb(struct ubi_device
*ubi
, struct ubi_volume
*vol
, int lnum
,
373 void *buf
, int offset
, int len
, int check
)
375 int err
, pnum
, scrub
= 0, vol_id
= vol
->vol_id
;
376 struct ubi_vid_hdr
*vid_hdr
;
377 uint32_t uninitialized_var(crc
);
379 err
= leb_read_lock(ubi
, vol_id
, lnum
);
383 pnum
= vol
->eba_tbl
[lnum
];
386 * The logical eraseblock is not mapped, fill the whole buffer
387 * with 0xFF bytes. The exception is static volumes for which
388 * it is an error to read unmapped logical eraseblocks.
390 dbg_eba("read %d bytes from offset %d of LEB %d:%d (unmapped)",
391 len
, offset
, vol_id
, lnum
);
392 leb_read_unlock(ubi
, vol_id
, lnum
);
393 ubi_assert(vol
->vol_type
!= UBI_STATIC_VOLUME
);
394 memset(buf
, 0xFF, len
);
398 dbg_eba("read %d bytes from offset %d of LEB %d:%d, PEB %d",
399 len
, offset
, vol_id
, lnum
, pnum
);
401 if (vol
->vol_type
== UBI_DYNAMIC_VOLUME
)
406 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
412 err
= ubi_io_read_vid_hdr(ubi
, pnum
, vid_hdr
, 1);
413 if (err
&& err
!= UBI_IO_BITFLIPS
) {
416 * The header is either absent or corrupted.
417 * The former case means there is a bug -
418 * switch to read-only mode just in case.
419 * The latter case means a real corruption - we
420 * may try to recover data. FIXME: but this is
423 if (err
== UBI_IO_BAD_HDR_EBADMSG
||
424 err
== UBI_IO_BAD_HDR
) {
425 ubi_warn(ubi
, "corrupted VID header at PEB %d, LEB %d:%d",
434 } else if (err
== UBI_IO_BITFLIPS
)
437 ubi_assert(lnum
< be32_to_cpu(vid_hdr
->used_ebs
));
438 ubi_assert(len
== be32_to_cpu(vid_hdr
->data_size
));
440 crc
= be32_to_cpu(vid_hdr
->data_crc
);
441 ubi_free_vid_hdr(ubi
, vid_hdr
);
444 err
= ubi_io_read_data(ubi
, buf
, pnum
, offset
, len
);
446 if (err
== UBI_IO_BITFLIPS
)
448 else if (mtd_is_eccerr(err
)) {
449 if (vol
->vol_type
== UBI_DYNAMIC_VOLUME
)
453 ubi_msg(ubi
, "force data checking");
462 uint32_t crc1
= crc32(UBI_CRC32_INIT
, buf
, len
);
464 ubi_warn(ubi
, "CRC error: calculated %#08x, must be %#08x",
472 err
= ubi_wl_scrub_peb(ubi
, pnum
);
474 leb_read_unlock(ubi
, vol_id
, lnum
);
478 ubi_free_vid_hdr(ubi
, vid_hdr
);
480 leb_read_unlock(ubi
, vol_id
, lnum
);
485 * ubi_eba_read_leb_sg - read data into a scatter gather list.
486 * @ubi: UBI device description object
487 * @vol: volume description object
488 * @lnum: logical eraseblock number
489 * @sgl: UBI scatter gather list to store the read data
490 * @offset: offset from where to read
491 * @len: how many bytes to read
492 * @check: data CRC check flag
494 * This function works exactly like ubi_eba_read_leb(). But instead of
495 * storing the read data into a buffer it writes to an UBI scatter gather
498 int ubi_eba_read_leb_sg(struct ubi_device
*ubi
, struct ubi_volume
*vol
,
499 struct ubi_sgl
*sgl
, int lnum
, int offset
, int len
,
504 struct scatterlist
*sg
;
507 ubi_assert(sgl
->list_pos
< UBI_MAX_SG_COUNT
);
508 sg
= &sgl
->sg
[sgl
->list_pos
];
509 if (len
< sg
->length
- sgl
->page_pos
)
512 to_read
= sg
->length
- sgl
->page_pos
;
514 ret
= ubi_eba_read_leb(ubi
, vol
, lnum
,
515 sg_virt(sg
) + sgl
->page_pos
, offset
,
523 sgl
->page_pos
+= to_read
;
524 if (sgl
->page_pos
== sg
->length
) {
540 * recover_peb - recover from write failure.
541 * @ubi: UBI device description object
542 * @pnum: the physical eraseblock to recover
544 * @lnum: logical eraseblock number
545 * @buf: data which was not written because of the write failure
546 * @offset: offset of the failed write
547 * @len: how many bytes should have been written
549 * This function is called in case of a write failure and moves all good data
550 * from the potentially bad physical eraseblock to a good physical eraseblock.
551 * This function also writes the data which was not written due to the failure.
552 * Returns new physical eraseblock number in case of success, and a negative
553 * error code in case of failure.
555 static int recover_peb(struct ubi_device
*ubi
, int pnum
, int vol_id
, int lnum
,
556 const void *buf
, int offset
, int len
)
558 int err
, idx
= vol_id2idx(ubi
, vol_id
), new_pnum
, data_size
, tries
= 0;
559 struct ubi_volume
*vol
= ubi
->volumes
[idx
];
560 struct ubi_vid_hdr
*vid_hdr
;
562 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
567 new_pnum
= ubi_wl_get_peb(ubi
);
569 ubi_free_vid_hdr(ubi
, vid_hdr
);
573 ubi_msg(ubi
, "recover PEB %d, move data to PEB %d",
576 err
= ubi_io_read_vid_hdr(ubi
, pnum
, vid_hdr
, 1);
577 if (err
&& err
!= UBI_IO_BITFLIPS
) {
583 vid_hdr
->sqnum
= cpu_to_be64(ubi_next_sqnum(ubi
));
584 err
= ubi_io_write_vid_hdr(ubi
, new_pnum
, vid_hdr
);
588 data_size
= offset
+ len
;
589 mutex_lock(&ubi
->buf_mutex
);
590 memset(ubi
->peb_buf
+ offset
, 0xFF, len
);
592 /* Read everything before the area where the write failure happened */
594 err
= ubi_io_read_data(ubi
, ubi
->peb_buf
, pnum
, 0, offset
);
595 if (err
&& err
!= UBI_IO_BITFLIPS
)
599 memcpy(ubi
->peb_buf
+ offset
, buf
, len
);
601 err
= ubi_io_write_data(ubi
, ubi
->peb_buf
, new_pnum
, 0, data_size
);
603 mutex_unlock(&ubi
->buf_mutex
);
607 mutex_unlock(&ubi
->buf_mutex
);
608 ubi_free_vid_hdr(ubi
, vid_hdr
);
610 down_read(&ubi
->fm_sem
);
611 vol
->eba_tbl
[lnum
] = new_pnum
;
612 up_read(&ubi
->fm_sem
);
613 ubi_wl_put_peb(ubi
, vol_id
, lnum
, pnum
, 1);
615 ubi_msg(ubi
, "data was successfully recovered");
619 mutex_unlock(&ubi
->buf_mutex
);
621 ubi_wl_put_peb(ubi
, vol_id
, lnum
, new_pnum
, 1);
622 ubi_free_vid_hdr(ubi
, vid_hdr
);
627 * Bad luck? This physical eraseblock is bad too? Crud. Let's try to
630 ubi_warn(ubi
, "failed to write to PEB %d", new_pnum
);
631 ubi_wl_put_peb(ubi
, vol_id
, lnum
, new_pnum
, 1);
632 if (++tries
> UBI_IO_RETRIES
) {
633 ubi_free_vid_hdr(ubi
, vid_hdr
);
636 ubi_msg(ubi
, "try again");
641 * ubi_eba_write_leb - write data to dynamic volume.
642 * @ubi: UBI device description object
643 * @vol: volume description object
644 * @lnum: logical eraseblock number
645 * @buf: the data to write
646 * @offset: offset within the logical eraseblock where to write
647 * @len: how many bytes to write
649 * This function writes data to logical eraseblock @lnum of a dynamic volume
650 * @vol. Returns zero in case of success and a negative error code in case
651 * of failure. In case of error, it is possible that something was still
652 * written to the flash media, but may be some garbage.
654 int ubi_eba_write_leb(struct ubi_device
*ubi
, struct ubi_volume
*vol
, int lnum
,
655 const void *buf
, int offset
, int len
)
657 int err
, pnum
, tries
= 0, vol_id
= vol
->vol_id
;
658 struct ubi_vid_hdr
*vid_hdr
;
663 err
= leb_write_lock(ubi
, vol_id
, lnum
);
667 pnum
= vol
->eba_tbl
[lnum
];
669 dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d",
670 len
, offset
, vol_id
, lnum
, pnum
);
672 err
= ubi_io_write_data(ubi
, buf
, pnum
, offset
, len
);
674 ubi_warn(ubi
, "failed to write data to PEB %d", pnum
);
675 if (err
== -EIO
&& ubi
->bad_allowed
)
676 err
= recover_peb(ubi
, pnum
, vol_id
, lnum
, buf
,
681 leb_write_unlock(ubi
, vol_id
, lnum
);
686 * The logical eraseblock is not mapped. We have to get a free physical
687 * eraseblock and write the volume identifier header there first.
689 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
691 leb_write_unlock(ubi
, vol_id
, lnum
);
695 vid_hdr
->vol_type
= UBI_VID_DYNAMIC
;
696 vid_hdr
->sqnum
= cpu_to_be64(ubi_next_sqnum(ubi
));
697 vid_hdr
->vol_id
= cpu_to_be32(vol_id
);
698 vid_hdr
->lnum
= cpu_to_be32(lnum
);
699 vid_hdr
->compat
= ubi_get_compat(ubi
, vol_id
);
700 vid_hdr
->data_pad
= cpu_to_be32(vol
->data_pad
);
703 pnum
= ubi_wl_get_peb(ubi
);
705 ubi_free_vid_hdr(ubi
, vid_hdr
);
706 leb_write_unlock(ubi
, vol_id
, lnum
);
710 dbg_eba("write VID hdr and %d bytes at offset %d of LEB %d:%d, PEB %d",
711 len
, offset
, vol_id
, lnum
, pnum
);
713 err
= ubi_io_write_vid_hdr(ubi
, pnum
, vid_hdr
);
715 ubi_warn(ubi
, "failed to write VID header to LEB %d:%d, PEB %d",
721 err
= ubi_io_write_data(ubi
, buf
, pnum
, offset
, len
);
723 ubi_warn(ubi
, "failed to write %d bytes at offset %d of LEB %d:%d, PEB %d",
724 len
, offset
, vol_id
, lnum
, pnum
);
729 down_read(&ubi
->fm_sem
);
730 vol
->eba_tbl
[lnum
] = pnum
;
731 up_read(&ubi
->fm_sem
);
733 leb_write_unlock(ubi
, vol_id
, lnum
);
734 ubi_free_vid_hdr(ubi
, vid_hdr
);
738 if (err
!= -EIO
|| !ubi
->bad_allowed
) {
740 leb_write_unlock(ubi
, vol_id
, lnum
);
741 ubi_free_vid_hdr(ubi
, vid_hdr
);
746 * Fortunately, this is the first write operation to this physical
747 * eraseblock, so just put it and request a new one. We assume that if
748 * this physical eraseblock went bad, the erase code will handle that.
750 err
= ubi_wl_put_peb(ubi
, vol_id
, lnum
, pnum
, 1);
751 if (err
|| ++tries
> UBI_IO_RETRIES
) {
753 leb_write_unlock(ubi
, vol_id
, lnum
);
754 ubi_free_vid_hdr(ubi
, vid_hdr
);
758 vid_hdr
->sqnum
= cpu_to_be64(ubi_next_sqnum(ubi
));
759 ubi_msg(ubi
, "try another PEB");
764 * ubi_eba_write_leb_st - write data to static volume.
765 * @ubi: UBI device description object
766 * @vol: volume description object
767 * @lnum: logical eraseblock number
768 * @buf: data to write
769 * @len: how many bytes to write
770 * @used_ebs: how many logical eraseblocks will this volume contain
772 * This function writes data to logical eraseblock @lnum of static volume
773 * @vol. The @used_ebs argument should contain total number of logical
774 * eraseblock in this static volume.
776 * When writing to the last logical eraseblock, the @len argument doesn't have
777 * to be aligned to the minimal I/O unit size. Instead, it has to be equivalent
778 * to the real data size, although the @buf buffer has to contain the
779 * alignment. In all other cases, @len has to be aligned.
781 * It is prohibited to write more than once to logical eraseblocks of static
782 * volumes. This function returns zero in case of success and a negative error
783 * code in case of failure.
785 int ubi_eba_write_leb_st(struct ubi_device
*ubi
, struct ubi_volume
*vol
,
786 int lnum
, const void *buf
, int len
, int used_ebs
)
788 int err
, pnum
, tries
= 0, data_size
= len
, vol_id
= vol
->vol_id
;
789 struct ubi_vid_hdr
*vid_hdr
;
795 if (lnum
== used_ebs
- 1)
796 /* If this is the last LEB @len may be unaligned */
797 len
= ALIGN(data_size
, ubi
->min_io_size
);
799 ubi_assert(!(len
& (ubi
->min_io_size
- 1)));
801 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
805 err
= leb_write_lock(ubi
, vol_id
, lnum
);
807 ubi_free_vid_hdr(ubi
, vid_hdr
);
811 vid_hdr
->sqnum
= cpu_to_be64(ubi_next_sqnum(ubi
));
812 vid_hdr
->vol_id
= cpu_to_be32(vol_id
);
813 vid_hdr
->lnum
= cpu_to_be32(lnum
);
814 vid_hdr
->compat
= ubi_get_compat(ubi
, vol_id
);
815 vid_hdr
->data_pad
= cpu_to_be32(vol
->data_pad
);
817 crc
= crc32(UBI_CRC32_INIT
, buf
, data_size
);
818 vid_hdr
->vol_type
= UBI_VID_STATIC
;
819 vid_hdr
->data_size
= cpu_to_be32(data_size
);
820 vid_hdr
->used_ebs
= cpu_to_be32(used_ebs
);
821 vid_hdr
->data_crc
= cpu_to_be32(crc
);
824 pnum
= ubi_wl_get_peb(ubi
);
826 ubi_free_vid_hdr(ubi
, vid_hdr
);
827 leb_write_unlock(ubi
, vol_id
, lnum
);
831 dbg_eba("write VID hdr and %d bytes at LEB %d:%d, PEB %d, used_ebs %d",
832 len
, vol_id
, lnum
, pnum
, used_ebs
);
834 err
= ubi_io_write_vid_hdr(ubi
, pnum
, vid_hdr
);
836 ubi_warn(ubi
, "failed to write VID header to LEB %d:%d, PEB %d",
841 err
= ubi_io_write_data(ubi
, buf
, pnum
, 0, len
);
843 ubi_warn(ubi
, "failed to write %d bytes of data to PEB %d",
848 ubi_assert(vol
->eba_tbl
[lnum
] < 0);
849 down_read(&ubi
->fm_sem
);
850 vol
->eba_tbl
[lnum
] = pnum
;
851 up_read(&ubi
->fm_sem
);
853 leb_write_unlock(ubi
, vol_id
, lnum
);
854 ubi_free_vid_hdr(ubi
, vid_hdr
);
858 if (err
!= -EIO
|| !ubi
->bad_allowed
) {
860 * This flash device does not admit of bad eraseblocks or
861 * something nasty and unexpected happened. Switch to read-only
865 leb_write_unlock(ubi
, vol_id
, lnum
);
866 ubi_free_vid_hdr(ubi
, vid_hdr
);
870 err
= ubi_wl_put_peb(ubi
, vol_id
, lnum
, pnum
, 1);
871 if (err
|| ++tries
> UBI_IO_RETRIES
) {
873 leb_write_unlock(ubi
, vol_id
, lnum
);
874 ubi_free_vid_hdr(ubi
, vid_hdr
);
878 vid_hdr
->sqnum
= cpu_to_be64(ubi_next_sqnum(ubi
));
879 ubi_msg(ubi
, "try another PEB");
884 * ubi_eba_atomic_leb_change - change logical eraseblock atomically.
885 * @ubi: UBI device description object
886 * @vol: volume description object
887 * @lnum: logical eraseblock number
888 * @buf: data to write
889 * @len: how many bytes to write
891 * This function changes the contents of a logical eraseblock atomically. @buf
892 * has to contain new logical eraseblock data, and @len - the length of the
893 * data, which has to be aligned. This function guarantees that in case of an
894 * unclean reboot the old contents is preserved. Returns zero in case of
895 * success and a negative error code in case of failure.
897 * UBI reserves one LEB for the "atomic LEB change" operation, so only one
898 * LEB change may be done at a time. This is ensured by @ubi->alc_mutex.
900 int ubi_eba_atomic_leb_change(struct ubi_device
*ubi
, struct ubi_volume
*vol
,
901 int lnum
, const void *buf
, int len
)
903 int err
, pnum
, tries
= 0, vol_id
= vol
->vol_id
;
904 struct ubi_vid_hdr
*vid_hdr
;
912 * Special case when data length is zero. In this case the LEB
913 * has to be unmapped and mapped somewhere else.
915 err
= ubi_eba_unmap_leb(ubi
, vol
, lnum
);
918 return ubi_eba_write_leb(ubi
, vol
, lnum
, NULL
, 0, 0);
921 vid_hdr
= ubi_zalloc_vid_hdr(ubi
, GFP_NOFS
);
925 mutex_lock(&ubi
->alc_mutex
);
926 err
= leb_write_lock(ubi
, vol_id
, lnum
);
930 vid_hdr
->sqnum
= cpu_to_be64(ubi_next_sqnum(ubi
));
931 vid_hdr
->vol_id
= cpu_to_be32(vol_id
);
932 vid_hdr
->lnum
= cpu_to_be32(lnum
);
933 vid_hdr
->compat
= ubi_get_compat(ubi
, vol_id
);
934 vid_hdr
->data_pad
= cpu_to_be32(vol
->data_pad
);
936 crc
= crc32(UBI_CRC32_INIT
, buf
, len
);
937 vid_hdr
->vol_type
= UBI_VID_DYNAMIC
;
938 vid_hdr
->data_size
= cpu_to_be32(len
);
939 vid_hdr
->copy_flag
= 1;
940 vid_hdr
->data_crc
= cpu_to_be32(crc
);
943 pnum
= ubi_wl_get_peb(ubi
);
949 dbg_eba("change LEB %d:%d, PEB %d, write VID hdr to PEB %d",
950 vol_id
, lnum
, vol
->eba_tbl
[lnum
], pnum
);
952 err
= ubi_io_write_vid_hdr(ubi
, pnum
, vid_hdr
);
954 ubi_warn(ubi
, "failed to write VID header to LEB %d:%d, PEB %d",
959 err
= ubi_io_write_data(ubi
, buf
, pnum
, 0, len
);
961 ubi_warn(ubi
, "failed to write %d bytes of data to PEB %d",
966 if (vol
->eba_tbl
[lnum
] >= 0) {
967 err
= ubi_wl_put_peb(ubi
, vol_id
, lnum
, vol
->eba_tbl
[lnum
], 0);
972 down_read(&ubi
->fm_sem
);
973 vol
->eba_tbl
[lnum
] = pnum
;
974 up_read(&ubi
->fm_sem
);
977 leb_write_unlock(ubi
, vol_id
, lnum
);
979 mutex_unlock(&ubi
->alc_mutex
);
980 ubi_free_vid_hdr(ubi
, vid_hdr
);
984 if (err
!= -EIO
|| !ubi
->bad_allowed
) {
986 * This flash device does not admit of bad eraseblocks or
987 * something nasty and unexpected happened. Switch to read-only
994 err
= ubi_wl_put_peb(ubi
, vol_id
, lnum
, pnum
, 1);
995 if (err
|| ++tries
> UBI_IO_RETRIES
) {
1000 vid_hdr
->sqnum
= cpu_to_be64(ubi_next_sqnum(ubi
));
1001 ubi_msg(ubi
, "try another PEB");
1006 * is_error_sane - check whether a read error is sane.
1007 * @err: code of the error happened during reading
1009 * This is a helper function for 'ubi_eba_copy_leb()' which is called when we
1010 * cannot read data from the target PEB (an error @err happened). If the error
1011 * code is sane, then we treat this error as non-fatal. Otherwise the error is
1012 * fatal and UBI will be switched to R/O mode later.
1014 * The idea is that we try not to switch to R/O mode if the read error is
1015 * something which suggests there was a real read problem. E.g., %-EIO. Or a
1016 * memory allocation failed (-%ENOMEM). Otherwise, it is safer to switch to R/O
1017 * mode, simply because we do not know what happened at the MTD level, and we
1018 * cannot handle this. E.g., the underlying driver may have become crazy, and
1019 * it is safer to switch to R/O mode to preserve the data.
1021 * And bear in mind, this is about reading from the target PEB, i.e. the PEB
1022 * which we have just written.
1024 static int is_error_sane(int err
)
1026 if (err
== -EIO
|| err
== -ENOMEM
|| err
== UBI_IO_BAD_HDR
||
1027 err
== UBI_IO_BAD_HDR_EBADMSG
|| err
== -ETIMEDOUT
)
1033 * ubi_eba_copy_leb - copy logical eraseblock.
1034 * @ubi: UBI device description object
1035 * @from: physical eraseblock number from where to copy
1036 * @to: physical eraseblock number where to copy
1037 * @vid_hdr: VID header of the @from physical eraseblock
1039 * This function copies logical eraseblock from physical eraseblock @from to
1040 * physical eraseblock @to. The @vid_hdr buffer may be changed by this
1041 * function. Returns:
1042 * o %0 in case of success;
1043 * o %MOVE_CANCEL_RACE, %MOVE_TARGET_WR_ERR, %MOVE_TARGET_BITFLIPS, etc;
1044 * o a negative error code in case of failure.
1046 int ubi_eba_copy_leb(struct ubi_device
*ubi
, int from
, int to
,
1047 struct ubi_vid_hdr
*vid_hdr
)
1049 int err
, vol_id
, lnum
, data_size
, aldata_size
, idx
;
1050 struct ubi_volume
*vol
;
1053 vol_id
= be32_to_cpu(vid_hdr
->vol_id
);
1054 lnum
= be32_to_cpu(vid_hdr
->lnum
);
1056 dbg_wl("copy LEB %d:%d, PEB %d to PEB %d", vol_id
, lnum
, from
, to
);
1058 if (vid_hdr
->vol_type
== UBI_VID_STATIC
) {
1059 data_size
= be32_to_cpu(vid_hdr
->data_size
);
1060 aldata_size
= ALIGN(data_size
, ubi
->min_io_size
);
1062 data_size
= aldata_size
=
1063 ubi
->leb_size
- be32_to_cpu(vid_hdr
->data_pad
);
1065 idx
= vol_id2idx(ubi
, vol_id
);
1066 spin_lock(&ubi
->volumes_lock
);
1068 * Note, we may race with volume deletion, which means that the volume
1069 * this logical eraseblock belongs to might be being deleted. Since the
1070 * volume deletion un-maps all the volume's logical eraseblocks, it will
1071 * be locked in 'ubi_wl_put_peb()' and wait for the WL worker to finish.
1073 vol
= ubi
->volumes
[idx
];
1074 spin_unlock(&ubi
->volumes_lock
);
1076 /* No need to do further work, cancel */
1077 dbg_wl("volume %d is being removed, cancel", vol_id
);
1078 return MOVE_CANCEL_RACE
;
1082 * We do not want anybody to write to this logical eraseblock while we
1083 * are moving it, so lock it.
1085 * Note, we are using non-waiting locking here, because we cannot sleep
1086 * on the LEB, since it may cause deadlocks. Indeed, imagine a task is
1087 * unmapping the LEB which is mapped to the PEB we are going to move
1088 * (@from). This task locks the LEB and goes sleep in the
1089 * 'ubi_wl_put_peb()' function on the @ubi->move_mutex. In turn, we are
1090 * holding @ubi->move_mutex and go sleep on the LEB lock. So, if the
1091 * LEB is already locked, we just do not move it and return
1092 * %MOVE_RETRY. Note, we do not return %MOVE_CANCEL_RACE here because
1093 * we do not know the reasons of the contention - it may be just a
1094 * normal I/O on this LEB, so we want to re-try.
1096 err
= leb_write_trylock(ubi
, vol_id
, lnum
);
1098 dbg_wl("contention on LEB %d:%d, cancel", vol_id
, lnum
);
1103 * The LEB might have been put meanwhile, and the task which put it is
1104 * probably waiting on @ubi->move_mutex. No need to continue the work,
1107 if (vol
->eba_tbl
[lnum
] != from
) {
1108 dbg_wl("LEB %d:%d is no longer mapped to PEB %d, mapped to PEB %d, cancel",
1109 vol_id
, lnum
, from
, vol
->eba_tbl
[lnum
]);
1110 err
= MOVE_CANCEL_RACE
;
1111 goto out_unlock_leb
;
1115 * OK, now the LEB is locked and we can safely start moving it. Since
1116 * this function utilizes the @ubi->peb_buf buffer which is shared
1117 * with some other functions - we lock the buffer by taking the
1120 mutex_lock(&ubi
->buf_mutex
);
1121 dbg_wl("read %d bytes of data", aldata_size
);
1122 err
= ubi_io_read_data(ubi
, ubi
->peb_buf
, from
, 0, aldata_size
);
1123 if (err
&& err
!= UBI_IO_BITFLIPS
) {
1124 ubi_warn(ubi
, "error %d while reading data from PEB %d",
1126 err
= MOVE_SOURCE_RD_ERR
;
1127 goto out_unlock_buf
;
1131 * Now we have got to calculate how much data we have to copy. In
1132 * case of a static volume it is fairly easy - the VID header contains
1133 * the data size. In case of a dynamic volume it is more difficult - we
1134 * have to read the contents, cut 0xFF bytes from the end and copy only
1135 * the first part. We must do this to avoid writing 0xFF bytes as it
1136 * may have some side-effects. And not only this. It is important not
1137 * to include those 0xFFs to CRC because later the they may be filled
1140 if (vid_hdr
->vol_type
== UBI_VID_DYNAMIC
)
1141 aldata_size
= data_size
=
1142 ubi_calc_data_len(ubi
, ubi
->peb_buf
, data_size
);
1145 crc
= crc32(UBI_CRC32_INIT
, ubi
->peb_buf
, data_size
);
1149 * It may turn out to be that the whole @from physical eraseblock
1150 * contains only 0xFF bytes. Then we have to only write the VID header
1151 * and do not write any data. This also means we should not set
1152 * @vid_hdr->copy_flag, @vid_hdr->data_size, and @vid_hdr->data_crc.
1154 if (data_size
> 0) {
1155 vid_hdr
->copy_flag
= 1;
1156 vid_hdr
->data_size
= cpu_to_be32(data_size
);
1157 vid_hdr
->data_crc
= cpu_to_be32(crc
);
1159 vid_hdr
->sqnum
= cpu_to_be64(ubi_next_sqnum(ubi
));
1161 err
= ubi_io_write_vid_hdr(ubi
, to
, vid_hdr
);
1164 err
= MOVE_TARGET_WR_ERR
;
1165 goto out_unlock_buf
;
1170 /* Read the VID header back and check if it was written correctly */
1171 err
= ubi_io_read_vid_hdr(ubi
, to
, vid_hdr
, 1);
1173 if (err
!= UBI_IO_BITFLIPS
) {
1174 ubi_warn(ubi
, "error %d while reading VID header back from PEB %d",
1176 if (is_error_sane(err
))
1177 err
= MOVE_TARGET_RD_ERR
;
1179 err
= MOVE_TARGET_BITFLIPS
;
1180 goto out_unlock_buf
;
1183 if (data_size
> 0) {
1184 err
= ubi_io_write_data(ubi
, ubi
->peb_buf
, to
, 0, aldata_size
);
1187 err
= MOVE_TARGET_WR_ERR
;
1188 goto out_unlock_buf
;
1194 * We've written the data and are going to read it back to make
1195 * sure it was written correctly.
1197 memset(ubi
->peb_buf
, 0xFF, aldata_size
);
1198 err
= ubi_io_read_data(ubi
, ubi
->peb_buf
, to
, 0, aldata_size
);
1200 if (err
!= UBI_IO_BITFLIPS
) {
1201 ubi_warn(ubi
, "error %d while reading data back from PEB %d",
1203 if (is_error_sane(err
))
1204 err
= MOVE_TARGET_RD_ERR
;
1206 err
= MOVE_TARGET_BITFLIPS
;
1207 goto out_unlock_buf
;
1212 if (crc
!= crc32(UBI_CRC32_INIT
, ubi
->peb_buf
, data_size
)) {
1213 ubi_warn(ubi
, "read data back from PEB %d and it is different",
1216 goto out_unlock_buf
;
1220 ubi_assert(vol
->eba_tbl
[lnum
] == from
);
1221 down_read(&ubi
->fm_sem
);
1222 vol
->eba_tbl
[lnum
] = to
;
1223 up_read(&ubi
->fm_sem
);
1226 mutex_unlock(&ubi
->buf_mutex
);
1228 leb_write_unlock(ubi
, vol_id
, lnum
);
1233 * print_rsvd_warning - warn about not having enough reserved PEBs.
1234 * @ubi: UBI device description object
1236 * This is a helper function for 'ubi_eba_init()' which is called when UBI
1237 * cannot reserve enough PEBs for bad block handling. This function makes a
1238 * decision whether we have to print a warning or not. The algorithm is as
1240 * o if this is a new UBI image, then just print the warning
1241 * o if this is an UBI image which has already been used for some time, print
1242 * a warning only if we can reserve less than 10% of the expected amount of
1245 * The idea is that when UBI is used, PEBs become bad, and the reserved pool
1246 * of PEBs becomes smaller, which is normal and we do not want to scare users
1247 * with a warning every time they attach the MTD device. This was an issue
1248 * reported by real users.
1250 static void print_rsvd_warning(struct ubi_device
*ubi
,
1251 struct ubi_attach_info
*ai
)
1254 * The 1 << 18 (256KiB) number is picked randomly, just a reasonably
1255 * large number to distinguish between newly flashed and used images.
1257 if (ai
->max_sqnum
> (1 << 18)) {
1258 int min
= ubi
->beb_rsvd_level
/ 10;
1262 if (ubi
->beb_rsvd_pebs
> min
)
1266 ubi_warn(ubi
, "cannot reserve enough PEBs for bad PEB handling, reserved %d, need %d",
1267 ubi
->beb_rsvd_pebs
, ubi
->beb_rsvd_level
);
1268 if (ubi
->corr_peb_count
)
1269 ubi_warn(ubi
, "%d PEBs are corrupted and not used",
1270 ubi
->corr_peb_count
);
1274 * self_check_eba - run a self check on the EBA table constructed by fastmap.
1275 * @ubi: UBI device description object
1276 * @ai_fastmap: UBI attach info object created by fastmap
1277 * @ai_scan: UBI attach info object created by scanning
1279 * Returns < 0 in case of an internal error, 0 otherwise.
1280 * If a bad EBA table entry was found it will be printed out and
1281 * ubi_assert() triggers.
1283 int self_check_eba(struct ubi_device
*ubi
, struct ubi_attach_info
*ai_fastmap
,
1284 struct ubi_attach_info
*ai_scan
)
1286 int i
, j
, num_volumes
, ret
= 0;
1287 int **scan_eba
, **fm_eba
;
1288 struct ubi_ainf_volume
*av
;
1289 struct ubi_volume
*vol
;
1290 struct ubi_ainf_peb
*aeb
;
1293 num_volumes
= ubi
->vtbl_slots
+ UBI_INT_VOL_COUNT
;
1295 scan_eba
= kmalloc(sizeof(*scan_eba
) * num_volumes
, GFP_KERNEL
);
1299 fm_eba
= kmalloc(sizeof(*fm_eba
) * num_volumes
, GFP_KERNEL
);
1305 for (i
= 0; i
< num_volumes
; i
++) {
1306 vol
= ubi
->volumes
[i
];
1310 scan_eba
[i
] = kmalloc(vol
->reserved_pebs
* sizeof(**scan_eba
),
1317 fm_eba
[i
] = kmalloc(vol
->reserved_pebs
* sizeof(**fm_eba
),
1324 for (j
= 0; j
< vol
->reserved_pebs
; j
++)
1325 scan_eba
[i
][j
] = fm_eba
[i
][j
] = UBI_LEB_UNMAPPED
;
1327 av
= ubi_find_av(ai_scan
, idx2vol_id(ubi
, i
));
1331 ubi_rb_for_each_entry(rb
, aeb
, &av
->root
, u
.rb
)
1332 scan_eba
[i
][aeb
->lnum
] = aeb
->pnum
;
1334 av
= ubi_find_av(ai_fastmap
, idx2vol_id(ubi
, i
));
1338 ubi_rb_for_each_entry(rb
, aeb
, &av
->root
, u
.rb
)
1339 fm_eba
[i
][aeb
->lnum
] = aeb
->pnum
;
1341 for (j
= 0; j
< vol
->reserved_pebs
; j
++) {
1342 if (scan_eba
[i
][j
] != fm_eba
[i
][j
]) {
1343 if (scan_eba
[i
][j
] == UBI_LEB_UNMAPPED
||
1344 fm_eba
[i
][j
] == UBI_LEB_UNMAPPED
)
1347 ubi_err(ubi
, "LEB:%i:%i is PEB:%i instead of %i!",
1348 vol
->vol_id
, i
, fm_eba
[i
][j
],
1356 for (i
= 0; i
< num_volumes
; i
++) {
1357 if (!ubi
->volumes
[i
])
1370 * ubi_eba_init - initialize the EBA sub-system using attaching information.
1371 * @ubi: UBI device description object
1372 * @ai: attaching information
1374 * This function returns zero in case of success and a negative error code in
1377 int ubi_eba_init(struct ubi_device
*ubi
, struct ubi_attach_info
*ai
)
1379 int i
, j
, err
, num_volumes
;
1380 struct ubi_ainf_volume
*av
;
1381 struct ubi_volume
*vol
;
1382 struct ubi_ainf_peb
*aeb
;
1385 dbg_eba("initialize EBA sub-system");
1387 spin_lock_init(&ubi
->ltree_lock
);
1388 mutex_init(&ubi
->alc_mutex
);
1389 ubi
->ltree
= RB_ROOT
;
1391 ubi
->global_sqnum
= ai
->max_sqnum
+ 1;
1392 num_volumes
= ubi
->vtbl_slots
+ UBI_INT_VOL_COUNT
;
1394 for (i
= 0; i
< num_volumes
; i
++) {
1395 vol
= ubi
->volumes
[i
];
1401 vol
->eba_tbl
= kmalloc(vol
->reserved_pebs
* sizeof(int),
1403 if (!vol
->eba_tbl
) {
1408 for (j
= 0; j
< vol
->reserved_pebs
; j
++)
1409 vol
->eba_tbl
[j
] = UBI_LEB_UNMAPPED
;
1411 av
= ubi_find_av(ai
, idx2vol_id(ubi
, i
));
1415 ubi_rb_for_each_entry(rb
, aeb
, &av
->root
, u
.rb
) {
1416 if (aeb
->lnum
>= vol
->reserved_pebs
)
1418 * This may happen in case of an unclean reboot
1421 ubi_move_aeb_to_list(av
, aeb
, &ai
->erase
);
1422 vol
->eba_tbl
[aeb
->lnum
] = aeb
->pnum
;
1426 if (ubi
->avail_pebs
< EBA_RESERVED_PEBS
) {
1427 ubi_err(ubi
, "no enough physical eraseblocks (%d, need %d)",
1428 ubi
->avail_pebs
, EBA_RESERVED_PEBS
);
1429 if (ubi
->corr_peb_count
)
1430 ubi_err(ubi
, "%d PEBs are corrupted and not used",
1431 ubi
->corr_peb_count
);
1435 ubi
->avail_pebs
-= EBA_RESERVED_PEBS
;
1436 ubi
->rsvd_pebs
+= EBA_RESERVED_PEBS
;
1438 if (ubi
->bad_allowed
) {
1439 ubi_calculate_reserved(ubi
);
1441 if (ubi
->avail_pebs
< ubi
->beb_rsvd_level
) {
1442 /* No enough free physical eraseblocks */
1443 ubi
->beb_rsvd_pebs
= ubi
->avail_pebs
;
1444 print_rsvd_warning(ubi
, ai
);
1446 ubi
->beb_rsvd_pebs
= ubi
->beb_rsvd_level
;
1448 ubi
->avail_pebs
-= ubi
->beb_rsvd_pebs
;
1449 ubi
->rsvd_pebs
+= ubi
->beb_rsvd_pebs
;
1452 dbg_eba("EBA sub-system is initialized");
1456 for (i
= 0; i
< num_volumes
; i
++) {
1457 if (!ubi
->volumes
[i
])
1459 kfree(ubi
->volumes
[i
]->eba_tbl
);
1460 ubi
->volumes
[i
]->eba_tbl
= NULL
;