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kernel-fxtec-pro1x/drivers/mtd/ubi/eba.c
Kees Cook 6da2ec5605 treewide: kmalloc() -> kmalloc_array() 
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

        kmalloc(a * b, gfp)

with:
        kmalloc_array(a * b, gfp)

as well as handling cases of:

        kmalloc(a * b * c, gfp)

with:

        kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kmalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kmalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kmalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kmalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kmalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kmalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kmalloc(sizeof(THING) * C2, ...)
|
  kmalloc(sizeof(TYPE) * C2, ...)
|
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00

1713 lines
47 KiB
C
Raw Blame History

/*
* Copyright (c) International Business Machines Corp., 2006
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Artem Bityutskiy (Битюцкий Артём)
*/
/*
* The UBI Eraseblock Association (EBA) sub-system.
*
* This sub-system is responsible for I/O to/from logical eraseblock.
*
* Although in this implementation the EBA table is fully kept and managed in
* RAM, which assumes poor scalability, it might be (partially) maintained on
* flash in future implementations.
*
* The EBA sub-system implements per-logical eraseblock locking. Before
* accessing a logical eraseblock it is locked for reading or writing. The
* per-logical eraseblock locking is implemented by means of the lock tree. The
* lock tree is an RB-tree which refers all the currently locked logical
* eraseblocks. The lock tree elements are &struct ubi_ltree_entry objects.
* They are indexed by (@vol_id, @lnum) pairs.
*
* EBA also maintains the global sequence counter which is incremented each
* time a logical eraseblock is mapped to a physical eraseblock and it is
* stored in the volume identifier header. This means that each VID header has
* a unique sequence number. The sequence number is only increased an we assume
* 64 bits is enough to never overflow.
*/
#include <linux/slab.h>
#include <linux/crc32.h>
#include <linux/err.h>
#include "ubi.h"
/* Number of physical eraseblocks reserved for atomic LEB change operation */
#define EBA_RESERVED_PEBS 1
/**
* struct ubi_eba_entry - structure encoding a single LEB -> PEB association
* @pnum: the physical eraseblock number attached to the LEB
*
* This structure is encoding a LEB -> PEB association. Note that the LEB
* number is not stored here, because it is the index used to access the
* entries table.
*/
struct ubi_eba_entry {
int pnum;
};
/**
* struct ubi_eba_table - LEB -> PEB association information
* @entries: the LEB to PEB mapping (one entry per LEB).
*
* This structure is private to the EBA logic and should be kept here.
* It is encoding the LEB to PEB association table, and is subject to
* changes.
*/
struct ubi_eba_table {
struct ubi_eba_entry *entries;
};
/**
* next_sqnum - get next sequence number.
* @ubi: UBI device description object
*
* This function returns next sequence number to use, which is just the current
* global sequence counter value. It also increases the global sequence
* counter.
*/
unsigned long long ubi_next_sqnum(struct ubi_device *ubi)
{
unsigned long long sqnum;
spin_lock(&ubi->ltree_lock);
sqnum = ubi->global_sqnum++;
spin_unlock(&ubi->ltree_lock);
return sqnum;
}
/**
* ubi_get_compat - get compatibility flags of a volume.
* @ubi: UBI device description object
* @vol_id: volume ID
*
* This function returns compatibility flags for an internal volume. User
* volumes have no compatibility flags, so %0 is returned.
*/
static int ubi_get_compat(const struct ubi_device *ubi, int vol_id)
{
if (vol_id == UBI_LAYOUT_VOLUME_ID)
return UBI_LAYOUT_VOLUME_COMPAT;
return 0;
}
/**
* ubi_eba_get_ldesc - get information about a LEB
* @vol: volume description object
* @lnum: logical eraseblock number
* @ldesc: the LEB descriptor to fill
*
* Used to query information about a specific LEB.
* It is currently only returning the physical position of the LEB, but will be
* extended to provide more information.
*/
void ubi_eba_get_ldesc(struct ubi_volume *vol, int lnum,
struct ubi_eba_leb_desc *ldesc)
{
ldesc->lnum = lnum;
ldesc->pnum = vol->eba_tbl->entries[lnum].pnum;
}
/**
* ubi_eba_create_table - allocate a new EBA table and initialize it with all
* LEBs unmapped
* @vol: volume containing the EBA table to copy
* @nentries: number of entries in the table
*
* Allocate a new EBA table and initialize it with all LEBs unmapped.
* Returns a valid pointer if it succeed, an ERR_PTR() otherwise.
*/
struct ubi_eba_table *ubi_eba_create_table(struct ubi_volume *vol,
int nentries)
{
struct ubi_eba_table *tbl;
int err = -ENOMEM;
int i;
tbl = kzalloc(sizeof(*tbl), GFP_KERNEL);
if (!tbl)
return ERR_PTR(-ENOMEM);
tbl->entries = kmalloc_array(nentries, sizeof(*tbl->entries),
GFP_KERNEL);
if (!tbl->entries)
goto err;
for (i = 0; i < nentries; i++)
tbl->entries[i].pnum = UBI_LEB_UNMAPPED;
return tbl;
err:
kfree(tbl->entries);
kfree(tbl);
return ERR_PTR(err);
}
/**
* ubi_eba_destroy_table - destroy an EBA table
* @tbl: the table to destroy
*
* Destroy an EBA table.
*/
void ubi_eba_destroy_table(struct ubi_eba_table *tbl)
{
if (!tbl)
return;
kfree(tbl->entries);
kfree(tbl);
}
/**
* ubi_eba_copy_table - copy the EBA table attached to vol into another table
* @vol: volume containing the EBA table to copy
* @dst: destination
* @nentries: number of entries to copy
*
* Copy the EBA table stored in vol into the one pointed by dst.
*/
void ubi_eba_copy_table(struct ubi_volume *vol, struct ubi_eba_table *dst,
int nentries)
{
struct ubi_eba_table *src;
int i;
ubi_assert(dst && vol && vol->eba_tbl);
src = vol->eba_tbl;
for (i = 0; i < nentries; i++)
dst->entries[i].pnum = src->entries[i].pnum;
}
/**
* ubi_eba_replace_table - assign a new EBA table to a volume
* @vol: volume containing the EBA table to copy
* @tbl: new EBA table
*
* Assign a new EBA table to the volume and release the old one.
*/
void ubi_eba_replace_table(struct ubi_volume *vol, struct ubi_eba_table *tbl)
{
ubi_eba_destroy_table(vol->eba_tbl);
vol->eba_tbl = tbl;
}
/**
* ltree_lookup - look up the lock tree.
* @ubi: UBI device description object
* @vol_id: volume ID
* @lnum: logical eraseblock number
*
* This function returns a pointer to the corresponding &struct ubi_ltree_entry
* object if the logical eraseblock is locked and %NULL if it is not.
* @ubi->ltree_lock has to be locked.
*/
static struct ubi_ltree_entry *ltree_lookup(struct ubi_device *ubi, int vol_id,
int lnum)
{
struct rb_node *p;
p = ubi->ltree.rb_node;
while (p) {
struct ubi_ltree_entry *le;
le = rb_entry(p, struct ubi_ltree_entry, rb);
if (vol_id < le->vol_id)
p = p->rb_left;
else if (vol_id > le->vol_id)
p = p->rb_right;
else {
if (lnum < le->lnum)
p = p->rb_left;
else if (lnum > le->lnum)
p = p->rb_right;
else
return le;
}
}
return NULL;
}
/**
* ltree_add_entry - add new entry to the lock tree.
* @ubi: UBI device description object
* @vol_id: volume ID
* @lnum: logical eraseblock number
*
* This function adds new entry for logical eraseblock (@vol_id, @lnum) to the
* lock tree. If such entry is already there, its usage counter is increased.
* Returns pointer to the lock tree entry or %-ENOMEM if memory allocation
* failed.
*/
static struct ubi_ltree_entry *ltree_add_entry(struct ubi_device *ubi,
int vol_id, int lnum)
{
struct ubi_ltree_entry *le, *le1, *le_free;
le = kmalloc(sizeof(struct ubi_ltree_entry), GFP_NOFS);
if (!le)
return ERR_PTR(-ENOMEM);
le->users = 0;
init_rwsem(&le->mutex);
le->vol_id = vol_id;
le->lnum = lnum;
spin_lock(&ubi->ltree_lock);
le1 = ltree_lookup(ubi, vol_id, lnum);
if (le1) {
/*
* This logical eraseblock is already locked. The newly
* allocated lock entry is not needed.
*/
le_free = le;
le = le1;
} else {
struct rb_node **p, *parent = NULL;
/*
* No lock entry, add the newly allocated one to the
* @ubi->ltree RB-tree.
*/
le_free = NULL;
p = &ubi->ltree.rb_node;
while (*p) {
parent = *p;
le1 = rb_entry(parent, struct ubi_ltree_entry, rb);
if (vol_id < le1->vol_id)
p = &(*p)->rb_left;
else if (vol_id > le1->vol_id)
p = &(*p)->rb_right;
else {
ubi_assert(lnum != le1->lnum);
if (lnum < le1->lnum)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
}
rb_link_node(&le->rb, parent, p);
rb_insert_color(&le->rb, &ubi->ltree);
}
le->users += 1;
spin_unlock(&ubi->ltree_lock);
kfree(le_free);
return le;
}
/**
* leb_read_lock - lock logical eraseblock for reading.
* @ubi: UBI device description object
* @vol_id: volume ID
* @lnum: logical eraseblock number
*
* This function locks a logical eraseblock for reading. Returns zero in case
* of success and a negative error code in case of failure.
*/
static int leb_read_lock(struct ubi_device *ubi, int vol_id, int lnum)
{
struct ubi_ltree_entry *le;
le = ltree_add_entry(ubi, vol_id, lnum);
if (IS_ERR(le))
return PTR_ERR(le);
down_read(&le->mutex);
return 0;
}
/**
* leb_read_unlock - unlock logical eraseblock.
* @ubi: UBI device description object
* @vol_id: volume ID
* @lnum: logical eraseblock number
*/
static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum)
{
struct ubi_ltree_entry *le;
spin_lock(&ubi->ltree_lock);
le = ltree_lookup(ubi, vol_id, lnum);
le->users -= 1;
ubi_assert(le->users >= 0);
up_read(&le->mutex);
if (le->users == 0) {
rb_erase(&le->rb, &ubi->ltree);
kfree(le);
}
spin_unlock(&ubi->ltree_lock);
}
/**
* leb_write_lock - lock logical eraseblock for writing.
* @ubi: UBI device description object
* @vol_id: volume ID
* @lnum: logical eraseblock number
*
* This function locks a logical eraseblock for writing. Returns zero in case
* of success and a negative error code in case of failure.
*/
static int leb_write_lock(struct ubi_device *ubi, int vol_id, int lnum)
{
struct ubi_ltree_entry *le;
le = ltree_add_entry(ubi, vol_id, lnum);
if (IS_ERR(le))
return PTR_ERR(le);
down_write(&le->mutex);
return 0;
}
/**
* leb_write_trylock - try to lock logical eraseblock for writing.
* @ubi: UBI device description object
* @vol_id: volume ID
* @lnum: logical eraseblock number
*
* This function locks a logical eraseblock for writing if there is no
* contention and does nothing if there is contention. Returns %0 in case of
* success, %1 in case of contention, and and a negative error code in case of
* failure.
*/
static int leb_write_trylock(struct ubi_device *ubi, int vol_id, int lnum)
{
struct ubi_ltree_entry *le;
le = ltree_add_entry(ubi, vol_id, lnum);
if (IS_ERR(le))
return PTR_ERR(le);
if (down_write_trylock(&le->mutex))
return 0;
/* Contention, cancel */
spin_lock(&ubi->ltree_lock);
le->users -= 1;
ubi_assert(le->users >= 0);
if (le->users == 0) {
rb_erase(&le->rb, &ubi->ltree);
kfree(le);
}
spin_unlock(&ubi->ltree_lock);
return 1;
}
/**
* leb_write_unlock - unlock logical eraseblock.
* @ubi: UBI device description object
* @vol_id: volume ID
* @lnum: logical eraseblock number
*/
static void leb_write_unlock(struct ubi_device *ubi, int vol_id, int lnum)
{
struct ubi_ltree_entry *le;
spin_lock(&ubi->ltree_lock);
le = ltree_lookup(ubi, vol_id, lnum);
le->users -= 1;
ubi_assert(le->users >= 0);
up_write(&le->mutex);
if (le->users == 0) {
rb_erase(&le->rb, &ubi->ltree);
kfree(le);
}
spin_unlock(&ubi->ltree_lock);
}
/**
* ubi_eba_is_mapped - check if a LEB is mapped.
* @vol: volume description object
* @lnum: logical eraseblock number
*
* This function returns true if the LEB is mapped, false otherwise.
*/
bool ubi_eba_is_mapped(struct ubi_volume *vol, int lnum)
{
return vol->eba_tbl->entries[lnum].pnum >= 0;
}
/**
* ubi_eba_unmap_leb - un-map logical eraseblock.
* @ubi: UBI device description object
* @vol: volume description object
* @lnum: logical eraseblock number
*
* This function un-maps logical eraseblock @lnum and schedules corresponding
* physical eraseblock for erasure. Returns zero in case of success and a
* negative error code in case of failure.
*/
int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
int lnum)
{
int err, pnum, vol_id = vol->vol_id;
if (ubi->ro_mode)
return -EROFS;
err = leb_write_lock(ubi, vol_id, lnum);
if (err)
return err;
pnum = vol->eba_tbl->entries[lnum].pnum;
if (pnum < 0)
/* This logical eraseblock is already unmapped */
goto out_unlock;
dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum);
down_read(&ubi->fm_eba_sem);
vol->eba_tbl->entries[lnum].pnum = UBI_LEB_UNMAPPED;
up_read(&ubi->fm_eba_sem);
err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 0);
out_unlock:
leb_write_unlock(ubi, vol_id, lnum);
return err;
}
#ifdef CONFIG_MTD_UBI_FASTMAP
/**
* check_mapping - check and fixup a mapping
* @ubi: UBI device description object
* @vol: volume description object
* @lnum: logical eraseblock number
* @pnum: physical eraseblock number
*
* Checks whether a given mapping is valid. Fastmap cannot track LEB unmap
* operations, if such an operation is interrupted the mapping still looks
* good, but upon first read an ECC is reported to the upper layer.
* Normaly during the full-scan at attach time this is fixed, for Fastmap
* we have to deal with it while reading.
* If the PEB behind a LEB shows this symthom we change the mapping to
* %UBI_LEB_UNMAPPED and schedule the PEB for erasure.
*
* Returns 0 on success, negative error code in case of failure.
*/
static int check_mapping(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
int *pnum)
{
int err;
struct ubi_vid_io_buf *vidb;
struct ubi_vid_hdr *vid_hdr;
if (!ubi->fast_attach)
return 0;
if (!vol->checkmap || test_bit(lnum, vol->checkmap))
return 0;
vidb = ubi_alloc_vid_buf(ubi, GFP_NOFS);
if (!vidb)
return -ENOMEM;
err = ubi_io_read_vid_hdr(ubi, *pnum, vidb, 0);
if (err > 0 && err != UBI_IO_BITFLIPS) {
int torture = 0;
switch (err) {
case UBI_IO_FF:
case UBI_IO_FF_BITFLIPS:
case UBI_IO_BAD_HDR:
case UBI_IO_BAD_HDR_EBADMSG:
break;
default:
ubi_assert(0);
}
if (err == UBI_IO_BAD_HDR_EBADMSG || err == UBI_IO_FF_BITFLIPS)
torture = 1;
down_read(&ubi->fm_eba_sem);
vol->eba_tbl->entries[lnum].pnum = UBI_LEB_UNMAPPED;
up_read(&ubi->fm_eba_sem);
ubi_wl_put_peb(ubi, vol->vol_id, lnum, *pnum, torture);
*pnum = UBI_LEB_UNMAPPED;
} else if (err < 0) {
ubi_err(ubi, "unable to read VID header back from PEB %i: %i",
*pnum, err);
goto out_free;
} else {
int found_vol_id, found_lnum;
ubi_assert(err == 0 || err == UBI_IO_BITFLIPS);
vid_hdr = ubi_get_vid_hdr(vidb);
found_vol_id = be32_to_cpu(vid_hdr->vol_id);
found_lnum = be32_to_cpu(vid_hdr->lnum);
if (found_lnum != lnum || found_vol_id != vol->vol_id) {
ubi_err(ubi, "EBA mismatch! PEB %i is LEB %i:%i instead of LEB %i:%i",
*pnum, found_vol_id, found_lnum, vol->vol_id, lnum);
ubi_ro_mode(ubi);
err = -EINVAL;
goto out_free;
}
}
set_bit(lnum, vol->checkmap);
err = 0;
out_free:
ubi_free_vid_buf(vidb);
return err;
}
#else
static int check_mapping(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
int *pnum)
{
return 0;
}
#endif
/**
* ubi_eba_read_leb - read data.
* @ubi: UBI device description object
* @vol: volume description object
* @lnum: logical eraseblock number
* @buf: buffer to store the read data
* @offset: offset from where to read
* @len: how many bytes to read
* @check: data CRC check flag
*
* If the logical eraseblock @lnum is unmapped, @buf is filled with 0xFF
* bytes. The @check flag only makes sense for static volumes and forces
* eraseblock data CRC checking.
*
* In case of success this function returns zero. In case of a static volume,
* if data CRC mismatches - %-EBADMSG is returned. %-EBADMSG may also be
* returned for any volume type if an ECC error was detected by the MTD device
* driver. Other negative error cored may be returned in case of other errors.
*/
int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
void *buf, int offset, int len, int check)
{
int err, pnum, scrub = 0, vol_id = vol->vol_id;
struct ubi_vid_io_buf *vidb;
struct ubi_vid_hdr *vid_hdr;
uint32_t uninitialized_var(crc);
err = leb_read_lock(ubi, vol_id, lnum);
if (err)
return err;
pnum = vol->eba_tbl->entries[lnum].pnum;
if (pnum >= 0) {
err = check_mapping(ubi, vol, lnum, &pnum);
if (err < 0)
goto out_unlock;
}
if (pnum == UBI_LEB_UNMAPPED) {
/*
* The logical eraseblock is not mapped, fill the whole buffer
* with 0xFF bytes. The exception is static volumes for which
* it is an error to read unmapped logical eraseblocks.
*/
dbg_eba("read %d bytes from offset %d of LEB %d:%d (unmapped)",
len, offset, vol_id, lnum);
leb_read_unlock(ubi, vol_id, lnum);
ubi_assert(vol->vol_type != UBI_STATIC_VOLUME);
memset(buf, 0xFF, len);
return 0;
}
dbg_eba("read %d bytes from offset %d of LEB %d:%d, PEB %d",
len, offset, vol_id, lnum, pnum);
if (vol->vol_type == UBI_DYNAMIC_VOLUME)
check = 0;
retry:
if (check) {
vidb = ubi_alloc_vid_buf(ubi, GFP_NOFS);
if (!vidb) {
err = -ENOMEM;
goto out_unlock;
}
vid_hdr = ubi_get_vid_hdr(vidb);
err = ubi_io_read_vid_hdr(ubi, pnum, vidb, 1);
if (err && err != UBI_IO_BITFLIPS) {
if (err > 0) {
/*
* The header is either absent or corrupted.
* The former case means there is a bug -
* switch to read-only mode just in case.
* The latter case means a real corruption - we
* may try to recover data. FIXME: but this is
* not implemented.
*/
if (err == UBI_IO_BAD_HDR_EBADMSG ||
err == UBI_IO_BAD_HDR) {
ubi_warn(ubi, "corrupted VID header at PEB %d, LEB %d:%d",
pnum, vol_id, lnum);
err = -EBADMSG;
} else {
/*
* Ending up here in the non-Fastmap case
* is a clear bug as the VID header had to
* be present at scan time to have it referenced.
* With fastmap the story is more complicated.
* Fastmap has the mapping info without the need
* of a full scan. So the LEB could have been
* unmapped, Fastmap cannot know this and keeps
* the LEB referenced.
* This is valid and works as the layer above UBI
* has to do bookkeeping about used/referenced
* LEBs in any case.
*/
if (ubi->fast_attach) {
err = -EBADMSG;
} else {
err = -EINVAL;
ubi_ro_mode(ubi);
}
}
}
goto out_free;
} else if (err == UBI_IO_BITFLIPS)
scrub = 1;
ubi_assert(lnum < be32_to_cpu(vid_hdr->used_ebs));
ubi_assert(len == be32_to_cpu(vid_hdr->data_size));
crc = be32_to_cpu(vid_hdr->data_crc);
ubi_free_vid_buf(vidb);
}
err = ubi_io_read_data(ubi, buf, pnum, offset, len);
if (err) {
if (err == UBI_IO_BITFLIPS)
scrub = 1;
else if (mtd_is_eccerr(err)) {
if (vol->vol_type == UBI_DYNAMIC_VOLUME)
goto out_unlock;
scrub = 1;
if (!check) {
ubi_msg(ubi, "force data checking");
check = 1;
goto retry;
}
} else
goto out_unlock;
}
if (check) {
uint32_t crc1 = crc32(UBI_CRC32_INIT, buf, len);
if (crc1 != crc) {
ubi_warn(ubi, "CRC error: calculated %#08x, must be %#08x",
crc1, crc);
err = -EBADMSG;
goto out_unlock;
}
}
if (scrub)
err = ubi_wl_scrub_peb(ubi, pnum);
leb_read_unlock(ubi, vol_id, lnum);
return err;
out_free:
ubi_free_vid_buf(vidb);
out_unlock:
leb_read_unlock(ubi, vol_id, lnum);
return err;
}
/**
* ubi_eba_read_leb_sg - read data into a scatter gather list.
* @ubi: UBI device description object
* @vol: volume description object
* @lnum: logical eraseblock number
* @sgl: UBI scatter gather list to store the read data
* @offset: offset from where to read
* @len: how many bytes to read
* @check: data CRC check flag
*
* This function works exactly like ubi_eba_read_leb(). But instead of
* storing the read data into a buffer it writes to an UBI scatter gather
* list.
*/
int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
struct ubi_sgl *sgl, int lnum, int offset, int len,
int check)
{
int to_read;
int ret;
struct scatterlist *sg;
for (;;) {
ubi_assert(sgl->list_pos < UBI_MAX_SG_COUNT);
sg = &sgl->sg[sgl->list_pos];
if (len < sg->length - sgl->page_pos)
to_read = len;
else
to_read = sg->length - sgl->page_pos;
ret = ubi_eba_read_leb(ubi, vol, lnum,
sg_virt(sg) + sgl->page_pos, offset,
to_read, check);
if (ret < 0)
return ret;
offset += to_read;
len -= to_read;
if (!len) {
sgl->page_pos += to_read;
if (sgl->page_pos == sg->length) {
sgl->list_pos++;
sgl->page_pos = 0;
}
break;
}
sgl->list_pos++;
sgl->page_pos = 0;
}
return ret;
}
/**
* try_recover_peb - try to recover from write failure.
* @vol: volume description object
* @pnum: the physical eraseblock to recover
* @lnum: logical eraseblock number
* @buf: data which was not written because of the write failure
* @offset: offset of the failed write
* @len: how many bytes should have been written
* @vidb: VID buffer
* @retry: whether the caller should retry in case of failure
*
* This function is called in case of a write failure and moves all good data
* from the potentially bad physical eraseblock to a good physical eraseblock.
* This function also writes the data which was not written due to the failure.
* Returns 0 in case of success, and a negative error code in case of failure.
* In case of failure, the %retry parameter is set to false if this is a fatal
* error (retrying won't help), and true otherwise.
*/
static int try_recover_peb(struct ubi_volume *vol, int pnum, int lnum,
const void *buf, int offset, int len,
struct ubi_vid_io_buf *vidb, bool *retry)
{
struct ubi_device *ubi = vol->ubi;
struct ubi_vid_hdr *vid_hdr;
int new_pnum, err, vol_id = vol->vol_id, data_size;
uint32_t crc;
*retry = false;
new_pnum = ubi_wl_get_peb(ubi);
if (new_pnum < 0) {
err = new_pnum;
goto out_put;
}
ubi_msg(ubi, "recover PEB %d, move data to PEB %d",
pnum, new_pnum);
err = ubi_io_read_vid_hdr(ubi, pnum, vidb, 1);
if (err && err != UBI_IO_BITFLIPS) {
if (err > 0)
err = -EIO;
goto out_put;
}
vid_hdr = ubi_get_vid_hdr(vidb);
ubi_assert(vid_hdr->vol_type == UBI_VID_DYNAMIC);
mutex_lock(&ubi->buf_mutex);
memset(ubi->peb_buf + offset, 0xFF, len);
/* Read everything before the area where the write failure happened */
if (offset > 0) {
err = ubi_io_read_data(ubi, ubi->peb_buf, pnum, 0, offset);
if (err && err != UBI_IO_BITFLIPS)
goto out_unlock;
}
*retry = true;
memcpy(ubi->peb_buf + offset, buf, len);
data_size = offset + len;
crc = crc32(UBI_CRC32_INIT, ubi->peb_buf, data_size);
vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
vid_hdr->copy_flag = 1;
vid_hdr->data_size = cpu_to_be32(data_size);
vid_hdr->data_crc = cpu_to_be32(crc);
err = ubi_io_write_vid_hdr(ubi, new_pnum, vidb);
if (err)
goto out_unlock;
err = ubi_io_write_data(ubi, ubi->peb_buf, new_pnum, 0, data_size);
out_unlock:
mutex_unlock(&ubi->buf_mutex);
if (!err)
vol->eba_tbl->entries[lnum].pnum = new_pnum;
out_put:
up_read(&ubi->fm_eba_sem);
if (!err) {
ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1);
ubi_msg(ubi, "data was successfully recovered");
} else if (new_pnum >= 0) {
/*
* Bad luck? This physical eraseblock is bad too? Crud. Let's
* try to get another one.
*/
ubi_wl_put_peb(ubi, vol_id, lnum, new_pnum, 1);
ubi_warn(ubi, "failed to write to PEB %d", new_pnum);
}
return err;
}
/**
* recover_peb - recover from write failure.
* @ubi: UBI device description object
* @pnum: the physical eraseblock to recover
* @vol_id: volume ID
* @lnum: logical eraseblock number
* @buf: data which was not written because of the write failure
* @offset: offset of the failed write
* @len: how many bytes should have been written
*
* This function is called in case of a write failure and moves all good data
* from the potentially bad physical eraseblock to a good physical eraseblock.
* This function also writes the data which was not written due to the failure.
* Returns 0 in case of success, and a negative error code in case of failure.
* This function tries %UBI_IO_RETRIES before giving up.
*/
static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
const void *buf, int offset, int len)
{
int err, idx = vol_id2idx(ubi, vol_id), tries;
struct ubi_volume *vol = ubi->volumes[idx];
struct ubi_vid_io_buf *vidb;
vidb = ubi_alloc_vid_buf(ubi, GFP_NOFS);
if (!vidb)
return -ENOMEM;
for (tries = 0; tries <= UBI_IO_RETRIES; tries++) {
bool retry;
err = try_recover_peb(vol, pnum, lnum, buf, offset, len, vidb,
&retry);
if (!err || !retry)
break;
ubi_msg(ubi, "try again");
}
ubi_free_vid_buf(vidb);
return err;
}
/**
* try_write_vid_and_data - try to write VID header and data to a new PEB.
* @vol: volume description object
* @lnum: logical eraseblock number
* @vidb: the VID buffer to write
* @buf: buffer containing the data
* @offset: where to start writing data
* @len: how many bytes should be written
*
* This function tries to write VID header and data belonging to logical
* eraseblock @lnum of volume @vol to a new physical eraseblock. Returns zero
* in case of success and a negative error code in case of failure.
* In case of error, it is possible that something was still written to the
* flash media, but may be some garbage.
*/
static int try_write_vid_and_data(struct ubi_volume *vol, int lnum,
struct ubi_vid_io_buf *vidb, const void *buf,
int offset, int len)
{
struct ubi_device *ubi = vol->ubi;
int pnum, opnum, err, vol_id = vol->vol_id;
pnum = ubi_wl_get_peb(ubi);
if (pnum < 0) {
err = pnum;
goto out_put;
}
opnum = vol->eba_tbl->entries[lnum].pnum;
dbg_eba("write VID hdr and %d bytes at offset %d of LEB %d:%d, PEB %d",
len, offset, vol_id, lnum, pnum);
err = ubi_io_write_vid_hdr(ubi, pnum, vidb);
if (err) {
ubi_warn(ubi, "failed to write VID header to LEB %d:%d, PEB %d",
vol_id, lnum, pnum);
goto out_put;
}
if (len) {
err = ubi_io_write_data(ubi, buf, pnum, offset, len);
if (err) {
ubi_warn(ubi,
"failed to write %d bytes at offset %d of LEB %d:%d, PEB %d",
len, offset, vol_id, lnum, pnum);
goto out_put;
}
}
vol->eba_tbl->entries[lnum].pnum = pnum;
out_put:
up_read(&ubi->fm_eba_sem);
if (err && pnum >= 0)
err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1);
else if (!err && opnum >= 0)
err = ubi_wl_put_peb(ubi, vol_id, lnum, opnum, 0);
return err;
}
/**
* ubi_eba_write_leb - write data to dynamic volume.
* @ubi: UBI device description object
* @vol: volume description object
* @lnum: logical eraseblock number
* @buf: the data to write
* @offset: offset within the logical eraseblock where to write
* @len: how many bytes to write
*
* This function writes data to logical eraseblock @lnum of a dynamic volume
* @vol. Returns zero in case of success and a negative error code in case
* of failure. In case of error, it is possible that something was still
* written to the flash media, but may be some garbage.
* This function retries %UBI_IO_RETRIES times before giving up.
*/
int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
const void *buf, int offset, int len)
{
int err, pnum, tries, vol_id = vol->vol_id;
struct ubi_vid_io_buf *vidb;
struct ubi_vid_hdr *vid_hdr;
if (ubi->ro_mode)
return -EROFS;
err = leb_write_lock(ubi, vol_id, lnum);
if (err)
return err;
pnum = vol->eba_tbl->entries[lnum].pnum;
if (pnum >= 0) {
err = check_mapping(ubi, vol, lnum, &pnum);
if (err < 0)
goto out;
}
if (pnum >= 0) {
dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d",
len, offset, vol_id, lnum, pnum);
err = ubi_io_write_data(ubi, buf, pnum, offset, len);
if (err) {
ubi_warn(ubi, "failed to write data to PEB %d", pnum);
if (err == -EIO && ubi->bad_allowed)
err = recover_peb(ubi, pnum, vol_id, lnum, buf,
offset, len);
}
goto out;
}
/*
* The logical eraseblock is not mapped. We have to get a free physical
* eraseblock and write the volume identifier header there first.
*/
vidb = ubi_alloc_vid_buf(ubi, GFP_NOFS);
if (!vidb) {
leb_write_unlock(ubi, vol_id, lnum);
return -ENOMEM;
}
vid_hdr = ubi_get_vid_hdr(vidb);
vid_hdr->vol_type = UBI_VID_DYNAMIC;
vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
vid_hdr->vol_id = cpu_to_be32(vol_id);
vid_hdr->lnum = cpu_to_be32(lnum);
vid_hdr->compat = ubi_get_compat(ubi, vol_id);
vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
for (tries = 0; tries <= UBI_IO_RETRIES; tries++) {
err = try_write_vid_and_data(vol, lnum, vidb, buf, offset, len);
if (err != -EIO || !ubi->bad_allowed)
break;
/*
* Fortunately, this is the first write operation to this
* physical eraseblock, so just put it and request a new one.
* We assume that if this physical eraseblock went bad, the
* erase code will handle that.
*/
vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
ubi_msg(ubi, "try another PEB");
}
ubi_free_vid_buf(vidb);
out:
if (err)
ubi_ro_mode(ubi);
leb_write_unlock(ubi, vol_id, lnum);
return err;
}
/**
* ubi_eba_write_leb_st - write data to static volume.
* @ubi: UBI device description object
* @vol: volume description object
* @lnum: logical eraseblock number
* @buf: data to write
* @len: how many bytes to write
* @used_ebs: how many logical eraseblocks will this volume contain
*
* This function writes data to logical eraseblock @lnum of static volume
* @vol. The @used_ebs argument should contain total number of logical
* eraseblock in this static volume.
*
* When writing to the last logical eraseblock, the @len argument doesn't have
* to be aligned to the minimal I/O unit size. Instead, it has to be equivalent
* to the real data size, although the @buf buffer has to contain the
* alignment. In all other cases, @len has to be aligned.
*
* It is prohibited to write more than once to logical eraseblocks of static
* volumes. This function returns zero in case of success and a negative error
* code in case of failure.
*/
int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
int lnum, const void *buf, int len, int used_ebs)
{
int err, tries, data_size = len, vol_id = vol->vol_id;
struct ubi_vid_io_buf *vidb;
struct ubi_vid_hdr *vid_hdr;
uint32_t crc;
if (ubi->ro_mode)
return -EROFS;
if (lnum == used_ebs - 1)
/* If this is the last LEB @len may be unaligned */
len = ALIGN(data_size, ubi->min_io_size);
else
ubi_assert(!(len & (ubi->min_io_size - 1)));
vidb = ubi_alloc_vid_buf(ubi, GFP_NOFS);
if (!vidb)
return -ENOMEM;
vid_hdr = ubi_get_vid_hdr(vidb);
err = leb_write_lock(ubi, vol_id, lnum);
if (err)
goto out;
vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
vid_hdr->vol_id = cpu_to_be32(vol_id);
vid_hdr->lnum = cpu_to_be32(lnum);
vid_hdr->compat = ubi_get_compat(ubi, vol_id);
vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
crc = crc32(UBI_CRC32_INIT, buf, data_size);
vid_hdr->vol_type = UBI_VID_STATIC;
vid_hdr->data_size = cpu_to_be32(data_size);
vid_hdr->used_ebs = cpu_to_be32(used_ebs);
vid_hdr->data_crc = cpu_to_be32(crc);
ubi_assert(vol->eba_tbl->entries[lnum].pnum < 0);
for (tries = 0; tries <= UBI_IO_RETRIES; tries++) {
err = try_write_vid_and_data(vol, lnum, vidb, buf, 0, len);
if (err != -EIO || !ubi->bad_allowed)
break;
vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
ubi_msg(ubi, "try another PEB");
}
if (err)
ubi_ro_mode(ubi);
leb_write_unlock(ubi, vol_id, lnum);
out:
ubi_free_vid_buf(vidb);
return err;
}
/*
* ubi_eba_atomic_leb_change - change logical eraseblock atomically.
* @ubi: UBI device description object
* @vol: volume description object
* @lnum: logical eraseblock number
* @buf: data to write
* @len: how many bytes to write
*
* This function changes the contents of a logical eraseblock atomically. @buf
* has to contain new logical eraseblock data, and @len - the length of the
* data, which has to be aligned. This function guarantees that in case of an
* unclean reboot the old contents is preserved. Returns zero in case of
* success and a negative error code in case of failure.
*
* UBI reserves one LEB for the "atomic LEB change" operation, so only one
* LEB change may be done at a time. This is ensured by @ubi->alc_mutex.
*/
int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
int lnum, const void *buf, int len)
{
int err, tries, vol_id = vol->vol_id;
struct ubi_vid_io_buf *vidb;
struct ubi_vid_hdr *vid_hdr;
uint32_t crc;
if (ubi->ro_mode)
return -EROFS;
if (len == 0) {
/*
* Special case when data length is zero. In this case the LEB
* has to be unmapped and mapped somewhere else.
*/
err = ubi_eba_unmap_leb(ubi, vol, lnum);
if (err)
return err;
return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0);
}
vidb = ubi_alloc_vid_buf(ubi, GFP_NOFS);
if (!vidb)
return -ENOMEM;
vid_hdr = ubi_get_vid_hdr(vidb);
mutex_lock(&ubi->alc_mutex);
err = leb_write_lock(ubi, vol_id, lnum);
if (err)
goto out_mutex;
vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
vid_hdr->vol_id = cpu_to_be32(vol_id);
vid_hdr->lnum = cpu_to_be32(lnum);
vid_hdr->compat = ubi_get_compat(ubi, vol_id);
vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
crc = crc32(UBI_CRC32_INIT, buf, len);
vid_hdr->vol_type = UBI_VID_DYNAMIC;
vid_hdr->data_size = cpu_to_be32(len);
vid_hdr->copy_flag = 1;
vid_hdr->data_crc = cpu_to_be32(crc);
dbg_eba("change LEB %d:%d", vol_id, lnum);
for (tries = 0; tries <= UBI_IO_RETRIES; tries++) {
err = try_write_vid_and_data(vol, lnum, vidb, buf, 0, len);
if (err != -EIO || !ubi->bad_allowed)
break;
vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
ubi_msg(ubi, "try another PEB");
}
/*
* This flash device does not admit of bad eraseblocks or
* something nasty and unexpected happened. Switch to read-only
* mode just in case.
*/
if (err)
ubi_ro_mode(ubi);
leb_write_unlock(ubi, vol_id, lnum);
out_mutex:
mutex_unlock(&ubi->alc_mutex);
ubi_free_vid_buf(vidb);
return err;
}
/**
* is_error_sane - check whether a read error is sane.
* @err: code of the error happened during reading
*
* This is a helper function for 'ubi_eba_copy_leb()' which is called when we
* cannot read data from the target PEB (an error @err happened). If the error
* code is sane, then we treat this error as non-fatal. Otherwise the error is
* fatal and UBI will be switched to R/O mode later.
*
* The idea is that we try not to switch to R/O mode if the read error is
* something which suggests there was a real read problem. E.g., %-EIO. Or a
* memory allocation failed (-%ENOMEM). Otherwise, it is safer to switch to R/O
* mode, simply because we do not know what happened at the MTD level, and we
* cannot handle this. E.g., the underlying driver may have become crazy, and
* it is safer to switch to R/O mode to preserve the data.
*
* And bear in mind, this is about reading from the target PEB, i.e. the PEB
* which we have just written.
*/
static int is_error_sane(int err)
{
if (err == -EIO || err == -ENOMEM || err == UBI_IO_BAD_HDR ||
err == UBI_IO_BAD_HDR_EBADMSG || err == -ETIMEDOUT)
return 0;
return 1;
}
/**
* ubi_eba_copy_leb - copy logical eraseblock.
* @ubi: UBI device description object
* @from: physical eraseblock number from where to copy
* @to: physical eraseblock number where to copy
* @vid_hdr: VID header of the @from physical eraseblock
*
* This function copies logical eraseblock from physical eraseblock @from to
* physical eraseblock @to. The @vid_hdr buffer may be changed by this
* function. Returns:
* o %0 in case of success;
* o %MOVE_CANCEL_RACE, %MOVE_TARGET_WR_ERR, %MOVE_TARGET_BITFLIPS, etc;
* o a negative error code in case of failure.
*/
int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
struct ubi_vid_io_buf *vidb)
{
int err, vol_id, lnum, data_size, aldata_size, idx;
struct ubi_vid_hdr *vid_hdr = ubi_get_vid_hdr(vidb);
struct ubi_volume *vol;
uint32_t crc;
ubi_assert(rwsem_is_locked(&ubi->fm_eba_sem));
vol_id = be32_to_cpu(vid_hdr->vol_id);
lnum = be32_to_cpu(vid_hdr->lnum);
dbg_wl("copy LEB %d:%d, PEB %d to PEB %d", vol_id, lnum, from, to);
if (vid_hdr->vol_type == UBI_VID_STATIC) {
data_size = be32_to_cpu(vid_hdr->data_size);
aldata_size = ALIGN(data_size, ubi->min_io_size);
} else
data_size = aldata_size =
ubi->leb_size - be32_to_cpu(vid_hdr->data_pad);
idx = vol_id2idx(ubi, vol_id);
spin_lock(&ubi->volumes_lock);
/*
* Note, we may race with volume deletion, which means that the volume
* this logical eraseblock belongs to might be being deleted. Since the
* volume deletion un-maps all the volume's logical eraseblocks, it will
* be locked in 'ubi_wl_put_peb()' and wait for the WL worker to finish.
*/
vol = ubi->volumes[idx];
spin_unlock(&ubi->volumes_lock);
if (!vol) {
/* No need to do further work, cancel */
dbg_wl("volume %d is being removed, cancel", vol_id);
return MOVE_CANCEL_RACE;
}
/*
* We do not want anybody to write to this logical eraseblock while we
* are moving it, so lock it.
*
* Note, we are using non-waiting locking here, because we cannot sleep
* on the LEB, since it may cause deadlocks. Indeed, imagine a task is
* unmapping the LEB which is mapped to the PEB we are going to move
* (@from). This task locks the LEB and goes sleep in the
* 'ubi_wl_put_peb()' function on the @ubi->move_mutex. In turn, we are
* holding @ubi->move_mutex and go sleep on the LEB lock. So, if the
* LEB is already locked, we just do not move it and return
* %MOVE_RETRY. Note, we do not return %MOVE_CANCEL_RACE here because
* we do not know the reasons of the contention - it may be just a
* normal I/O on this LEB, so we want to re-try.
*/
err = leb_write_trylock(ubi, vol_id, lnum);
if (err) {
dbg_wl("contention on LEB %d:%d, cancel", vol_id, lnum);
return MOVE_RETRY;
}
/*
* The LEB might have been put meanwhile, and the task which put it is
* probably waiting on @ubi->move_mutex. No need to continue the work,
* cancel it.
*/
if (vol->eba_tbl->entries[lnum].pnum != from) {
dbg_wl("LEB %d:%d is no longer mapped to PEB %d, mapped to PEB %d, cancel",
vol_id, lnum, from, vol->eba_tbl->entries[lnum].pnum);
err = MOVE_CANCEL_RACE;
goto out_unlock_leb;
}
/*
* OK, now the LEB is locked and we can safely start moving it. Since
* this function utilizes the @ubi->peb_buf buffer which is shared
* with some other functions - we lock the buffer by taking the
* @ubi->buf_mutex.
*/
mutex_lock(&ubi->buf_mutex);
dbg_wl("read %d bytes of data", aldata_size);
err = ubi_io_read_data(ubi, ubi->peb_buf, from, 0, aldata_size);
if (err && err != UBI_IO_BITFLIPS) {
ubi_warn(ubi, "error %d while reading data from PEB %d",
err, from);
err = MOVE_SOURCE_RD_ERR;
goto out_unlock_buf;
}
/*
* Now we have got to calculate how much data we have to copy. In
* case of a static volume it is fairly easy - the VID header contains
* the data size. In case of a dynamic volume it is more difficult - we
* have to read the contents, cut 0xFF bytes from the end and copy only
* the first part. We must do this to avoid writing 0xFF bytes as it
* may have some side-effects. And not only this. It is important not
* to include those 0xFFs to CRC because later the they may be filled
* by data.
*/
if (vid_hdr->vol_type == UBI_VID_DYNAMIC)
aldata_size = data_size =
ubi_calc_data_len(ubi, ubi->peb_buf, data_size);
cond_resched();
crc = crc32(UBI_CRC32_INIT, ubi->peb_buf, data_size);
cond_resched();
/*
* It may turn out to be that the whole @from physical eraseblock
* contains only 0xFF bytes. Then we have to only write the VID header
* and do not write any data. This also means we should not set
* @vid_hdr->copy_flag, @vid_hdr->data_size, and @vid_hdr->data_crc.
*/
if (data_size > 0) {
vid_hdr->copy_flag = 1;
vid_hdr->data_size = cpu_to_be32(data_size);
vid_hdr->data_crc = cpu_to_be32(crc);
}
vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
err = ubi_io_write_vid_hdr(ubi, to, vidb);
if (err) {
if (err == -EIO)
err = MOVE_TARGET_WR_ERR;
goto out_unlock_buf;
}
cond_resched();
/* Read the VID header back and check if it was written correctly */
err = ubi_io_read_vid_hdr(ubi, to, vidb, 1);
if (err) {
if (err != UBI_IO_BITFLIPS) {
ubi_warn(ubi, "error %d while reading VID header back from PEB %d",
err, to);
if (is_error_sane(err))
err = MOVE_TARGET_RD_ERR;
} else
err = MOVE_TARGET_BITFLIPS;
goto out_unlock_buf;
}
if (data_size > 0) {
err = ubi_io_write_data(ubi, ubi->peb_buf, to, 0, aldata_size);
if (err) {
if (err == -EIO)
err = MOVE_TARGET_WR_ERR;
goto out_unlock_buf;
}
cond_resched();
}
ubi_assert(vol->eba_tbl->entries[lnum].pnum == from);
vol->eba_tbl->entries[lnum].pnum = to;
out_unlock_buf:
mutex_unlock(&ubi->buf_mutex);
out_unlock_leb:
leb_write_unlock(ubi, vol_id, lnum);
return err;
}
/**
* print_rsvd_warning - warn about not having enough reserved PEBs.
* @ubi: UBI device description object
*
* This is a helper function for 'ubi_eba_init()' which is called when UBI
* cannot reserve enough PEBs for bad block handling. This function makes a
* decision whether we have to print a warning or not. The algorithm is as
* follows:
* o if this is a new UBI image, then just print the warning
* o if this is an UBI image which has already been used for some time, print
* a warning only if we can reserve less than 10% of the expected amount of
* the reserved PEB.
*
* The idea is that when UBI is used, PEBs become bad, and the reserved pool
* of PEBs becomes smaller, which is normal and we do not want to scare users
* with a warning every time they attach the MTD device. This was an issue
* reported by real users.
*/
static void print_rsvd_warning(struct ubi_device *ubi,
struct ubi_attach_info *ai)
{
/*
* The 1 << 18 (256KiB) number is picked randomly, just a reasonably
* large number to distinguish between newly flashed and used images.
*/
if (ai->max_sqnum > (1 << 18)) {
int min = ubi->beb_rsvd_level / 10;
if (!min)
min = 1;
if (ubi->beb_rsvd_pebs > min)
return;
}
ubi_warn(ubi, "cannot reserve enough PEBs for bad PEB handling, reserved %d, need %d",
ubi->beb_rsvd_pebs, ubi->beb_rsvd_level);
if (ubi->corr_peb_count)
ubi_warn(ubi, "%d PEBs are corrupted and not used",
ubi->corr_peb_count);
}
/**
* self_check_eba - run a self check on the EBA table constructed by fastmap.
* @ubi: UBI device description object
* @ai_fastmap: UBI attach info object created by fastmap
* @ai_scan: UBI attach info object created by scanning
*
* Returns < 0 in case of an internal error, 0 otherwise.
* If a bad EBA table entry was found it will be printed out and
* ubi_assert() triggers.
*/
int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
struct ubi_attach_info *ai_scan)
{
int i, j, num_volumes, ret = 0;
int **scan_eba, **fm_eba;
struct ubi_ainf_volume *av;
struct ubi_volume *vol;
struct ubi_ainf_peb *aeb;
struct rb_node *rb;
num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
scan_eba = kmalloc_array(num_volumes, sizeof(*scan_eba), GFP_KERNEL);
if (!scan_eba)
return -ENOMEM;
fm_eba = kmalloc_array(num_volumes, sizeof(*fm_eba), GFP_KERNEL);
if (!fm_eba) {
kfree(scan_eba);
return -ENOMEM;
}
for (i = 0; i < num_volumes; i++) {
vol = ubi->volumes[i];
if (!vol)
continue;
scan_eba[i] = kmalloc_array(vol->reserved_pebs,
sizeof(**scan_eba),
GFP_KERNEL);
if (!scan_eba[i]) {
ret = -ENOMEM;
goto out_free;
}
fm_eba[i] = kmalloc_array(vol->reserved_pebs,
sizeof(**fm_eba),
GFP_KERNEL);
if (!fm_eba[i]) {
ret = -ENOMEM;
goto out_free;
}
for (j = 0; j < vol->reserved_pebs; j++)
scan_eba[i][j] = fm_eba[i][j] = UBI_LEB_UNMAPPED;
av = ubi_find_av(ai_scan, idx2vol_id(ubi, i));
if (!av)
continue;
ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb)
scan_eba[i][aeb->lnum] = aeb->pnum;
av = ubi_find_av(ai_fastmap, idx2vol_id(ubi, i));
if (!av)
continue;
ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb)
fm_eba[i][aeb->lnum] = aeb->pnum;
for (j = 0; j < vol->reserved_pebs; j++) {
if (scan_eba[i][j] != fm_eba[i][j]) {
if (scan_eba[i][j] == UBI_LEB_UNMAPPED ||
fm_eba[i][j] == UBI_LEB_UNMAPPED)
continue;
ubi_err(ubi, "LEB:%i:%i is PEB:%i instead of %i!",
vol->vol_id, j, fm_eba[i][j],
scan_eba[i][j]);
ubi_assert(0);
}
}
}
out_free:
for (i = 0; i < num_volumes; i++) {
if (!ubi->volumes[i])
continue;
kfree(scan_eba[i]);
kfree(fm_eba[i]);
}
kfree(scan_eba);
kfree(fm_eba);
return ret;
}
/**
* ubi_eba_init - initialize the EBA sub-system using attaching information.
* @ubi: UBI device description object
* @ai: attaching information
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*/
int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
{
int i, err, num_volumes;
struct ubi_ainf_volume *av;
struct ubi_volume *vol;
struct ubi_ainf_peb *aeb;
struct rb_node *rb;
dbg_eba("initialize EBA sub-system");
spin_lock_init(&ubi->ltree_lock);
mutex_init(&ubi->alc_mutex);
ubi->ltree = RB_ROOT;
ubi->global_sqnum = ai->max_sqnum + 1;
num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
for (i = 0; i < num_volumes; i++) {
struct ubi_eba_table *tbl;
vol = ubi->volumes[i];
if (!vol)
continue;
cond_resched();
tbl = ubi_eba_create_table(vol, vol->reserved_pebs);
if (IS_ERR(tbl)) {
err = PTR_ERR(tbl);
goto out_free;
}
ubi_eba_replace_table(vol, tbl);
av = ubi_find_av(ai, idx2vol_id(ubi, i));
if (!av)
continue;
ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb) {
if (aeb->lnum >= vol->reserved_pebs) {
/*
* This may happen in case of an unclean reboot
* during re-size.
*/
ubi_move_aeb_to_list(av, aeb, &ai->erase);
} else {
struct ubi_eba_entry *entry;
entry = &vol->eba_tbl->entries[aeb->lnum];
entry->pnum = aeb->pnum;
}
}
}
if (ubi->avail_pebs < EBA_RESERVED_PEBS) {
ubi_err(ubi, "no enough physical eraseblocks (%d, need %d)",
ubi->avail_pebs, EBA_RESERVED_PEBS);
if (ubi->corr_peb_count)
ubi_err(ubi, "%d PEBs are corrupted and not used",
ubi->corr_peb_count);
err = -ENOSPC;
goto out_free;
}
ubi->avail_pebs -= EBA_RESERVED_PEBS;
ubi->rsvd_pebs += EBA_RESERVED_PEBS;
if (ubi->bad_allowed) {
ubi_calculate_reserved(ubi);
if (ubi->avail_pebs < ubi->beb_rsvd_level) {
/* No enough free physical eraseblocks */
ubi->beb_rsvd_pebs = ubi->avail_pebs;
print_rsvd_warning(ubi, ai);
} else
ubi->beb_rsvd_pebs = ubi->beb_rsvd_level;
ubi->avail_pebs -= ubi->beb_rsvd_pebs;
ubi->rsvd_pebs += ubi->beb_rsvd_pebs;
}
dbg_eba("EBA sub-system is initialized");
return 0;
out_free:
for (i = 0; i < num_volumes; i++) {
if (!ubi->volumes[i])
continue;
ubi_eba_replace_table(ubi->volumes[i], NULL);
}
return err;
}
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