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lpt.c
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/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* 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., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Adrian Hunter
* Artem Bityutskiy (Битюцкий Артём)
*/
/*
* This file implements the LEB properties tree (LPT) area. The LPT area
* contains the LEB properties tree, a table of LPT area eraseblocks (ltab), and
* (for the "big" model) a table of saved LEB numbers (lsave). The LPT area sits
* between the log and the orphan area.
*
* The LPT area is like a miniature self-contained file system. It is required
* that it never runs out of space, is fast to access and update, and scales
* logarithmically. The LEB properties tree is implemented as a wandering tree
* much like the TNC, and the LPT area has its own garbage collection.
*
* The LPT has two slightly different forms called the "small model" and the
* "big model". The small model is used when the entire LEB properties table
* can be written into a single eraseblock. In that case, garbage collection
* consists of just writing the whole table, which therefore makes all other
* eraseblocks reusable. In the case of the big model, dirty eraseblocks are
* selected for garbage collection, which consists of marking the clean nodes in
* that LEB as dirty, and then only the dirty nodes are written out. Also, in
* the case of the big model, a table of LEB numbers is saved so that the entire
* LPT does not to be scanned looking for empty eraseblocks when UBIFS is first
* mounted.
*/
#include "ubifs.h"
#include <linux/crc16.h>
#include <linux/math64.h>
#include <linux/slab.h>
/**
* do_calc_lpt_geom - calculate sizes for the LPT area.
* @c: the UBIFS file-system description object
*
* Calculate the sizes of LPT bit fields, nodes, and tree, based on the
* properties of the flash and whether LPT is "big" (c->big_lpt).
*/
static void do_calc_lpt_geom(struct ubifs_info *c)
{
int i, n, bits, per_leb_wastage, max_pnode_cnt;
long long sz, tot_wastage;
n = c->main_lebs + c->max_leb_cnt - c->leb_cnt;
max_pnode_cnt = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT);
c->lpt_hght = 1;
n = UBIFS_LPT_FANOUT;
while (n < max_pnode_cnt) {
c->lpt_hght += 1;
n <<= UBIFS_LPT_FANOUT_SHIFT;
}
c->pnode_cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
n = DIV_ROUND_UP(c->pnode_cnt, UBIFS_LPT_FANOUT);
c->nnode_cnt = n;
for (i = 1; i < c->lpt_hght; i++) {
n = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT);
c->nnode_cnt += n;
}
c->space_bits = fls(c->leb_size) - 3;
c->lpt_lnum_bits = fls(c->lpt_lebs);
c->lpt_offs_bits = fls(c->leb_size - 1);
c->lpt_spc_bits = fls(c->leb_size);
n = DIV_ROUND_UP(c->max_leb_cnt, UBIFS_LPT_FANOUT);
c->pcnt_bits = fls(n - 1);
c->lnum_bits = fls(c->max_leb_cnt - 1);
bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
(c->big_lpt ? c->pcnt_bits : 0) +
(c->space_bits * 2 + 1) * UBIFS_LPT_FANOUT;
c->pnode_sz = (bits + 7) / 8;
bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
(c->big_lpt ? c->pcnt_bits : 0) +
(c->lpt_lnum_bits + c->lpt_offs_bits) * UBIFS_LPT_FANOUT;
c->nnode_sz = (bits + 7) / 8;
bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
c->lpt_lebs * c->lpt_spc_bits * 2;
c->ltab_sz = (bits + 7) / 8;
bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
c->lnum_bits * c->lsave_cnt;
c->lsave_sz = (bits + 7) / 8;
/* Calculate the minimum LPT size */
c->lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
c->lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
c->lpt_sz += c->ltab_sz;
if (c->big_lpt)
c->lpt_sz += c->lsave_sz;
/* Add wastage */
sz = c->lpt_sz;
per_leb_wastage = max_t(int, c->pnode_sz, c->nnode_sz);
sz += per_leb_wastage;
tot_wastage = per_leb_wastage;
while (sz > c->leb_size) {
sz += per_leb_wastage;
sz -= c->leb_size;
tot_wastage += per_leb_wastage;
}
tot_wastage += ALIGN(sz, c->min_io_size) - sz;
c->lpt_sz += tot_wastage;
}
/**
* ubifs_calc_lpt_geom - calculate and check sizes for the LPT area.
* @c: the UBIFS file-system description object
*
* This function returns %0 on success and a negative error code on failure.
*/
int ubifs_calc_lpt_geom(struct ubifs_info *c)
{
int lebs_needed;
long long sz;
do_calc_lpt_geom(c);
/* Verify that lpt_lebs is big enough */
sz = c->lpt_sz * 2; /* Must have at least 2 times the size */
lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
if (lebs_needed > c->lpt_lebs) {
ubifs_err("too few LPT LEBs");
return -EINVAL;
}
/* Verify that ltab fits in a single LEB (since ltab is a single node */
if (c->ltab_sz > c->leb_size) {
ubifs_err("LPT ltab too big");
return -EINVAL;
}
c->check_lpt_free = c->big_lpt;
return 0;
}
/**
* calc_dflt_lpt_geom - calculate default LPT geometry.
* @c: the UBIFS file-system description object
* @main_lebs: number of main area LEBs is passed and returned here
* @big_lpt: whether the LPT area is "big" is returned here
*
* The size of the LPT area depends on parameters that themselves are dependent
* on the size of the LPT area. This function, successively recalculates the LPT
* area geometry until the parameters and resultant geometry are consistent.
*
* This function returns %0 on success and a negative error code on failure.
*/
static int calc_dflt_lpt_geom(struct ubifs_info *c, int *main_lebs,
int *big_lpt)
{
int i, lebs_needed;
long long sz;
/* Start by assuming the minimum number of LPT LEBs */
c->lpt_lebs = UBIFS_MIN_LPT_LEBS;
c->main_lebs = *main_lebs - c->lpt_lebs;
if (c->main_lebs <= 0)
return -EINVAL;
/* And assume we will use the small LPT model */
c->big_lpt = 0;
/*
* Calculate the geometry based on assumptions above and then see if it
* makes sense
*/
do_calc_lpt_geom(c);
/* Small LPT model must have lpt_sz < leb_size */
if (c->lpt_sz > c->leb_size) {
/* Nope, so try again using big LPT model */
c->big_lpt = 1;
do_calc_lpt_geom(c);
}
/* Now check there are enough LPT LEBs */
for (i = 0; i < 64 ; i++) {
sz = c->lpt_sz * 4; /* Allow 4 times the size */
lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
if (lebs_needed > c->lpt_lebs) {
/* Not enough LPT LEBs so try again with more */
c->lpt_lebs = lebs_needed;
c->main_lebs = *main_lebs - c->lpt_lebs;
if (c->main_lebs <= 0)
return -EINVAL;
do_calc_lpt_geom(c);
continue;
}
if (c->ltab_sz > c->leb_size) {
ubifs_err("LPT ltab too big");
return -EINVAL;
}
*main_lebs = c->main_lebs;
*big_lpt = c->big_lpt;
return 0;
}
return -EINVAL;
}
/**
* pack_bits - pack bit fields end-to-end.
* @addr: address at which to pack (passed and next address returned)
* @pos: bit position at which to pack (passed and next position returned)
* @val: value to pack
* @nrbits: number of bits of value to pack (1-32)
*/
static void pack_bits(uint8_t **addr, int *pos, uint32_t val, int nrbits)
{
uint8_t *p = *addr;
int b = *pos;
ubifs_assert(nrbits > 0);
ubifs_assert(nrbits <= 32);
ubifs_assert(*pos >= 0);
ubifs_assert(*pos < 8);
ubifs_assert((val >> nrbits) == 0 || nrbits == 32);
if (b) {
*p |= ((uint8_t)val) << b;
nrbits += b;
if (nrbits > 8) {
*++p = (uint8_t)(val >>= (8 - b));
if (nrbits > 16) {
*++p = (uint8_t)(val >>= 8);
if (nrbits > 24) {
*++p = (uint8_t)(val >>= 8);
if (nrbits > 32)
*++p = (uint8_t)(val >>= 8);
}
}
}
} else {
*p = (uint8_t)val;
if (nrbits > 8) {
*++p = (uint8_t)(val >>= 8);
if (nrbits > 16) {
*++p = (uint8_t)(val >>= 8);
if (nrbits > 24)
*++p = (uint8_t)(val >>= 8);
}
}
}
b = nrbits & 7;
if (b == 0)
p++;
*addr = p;
*pos = b;
}
/**
* ubifs_unpack_bits - unpack bit fields.
* @addr: address at which to unpack (passed and next address returned)
* @pos: bit position at which to unpack (passed and next position returned)
* @nrbits: number of bits of value to unpack (1-32)
*
* This functions returns the value unpacked.
*/
uint32_t ubifs_unpack_bits(uint8_t **addr, int *pos, int nrbits)
{
const int k = 32 - nrbits;
uint8_t *p = *addr;
int b = *pos;
uint32_t uninitialized_var(val);
const int bytes = (nrbits + b + 7) >> 3;
ubifs_assert(nrbits > 0);
ubifs_assert(nrbits <= 32);
ubifs_assert(*pos >= 0);
ubifs_assert(*pos < 8);
if (b) {
switch (bytes) {
case 2:
val = p[1];
break;
case 3:
val = p[1] | ((uint32_t)p[2] << 8);
break;
case 4:
val = p[1] | ((uint32_t)p[2] << 8) |
((uint32_t)p[3] << 16);
break;
case 5:
val = p[1] | ((uint32_t)p[2] << 8) |
((uint32_t)p[3] << 16) |
((uint32_t)p[4] << 24);
}
val <<= (8 - b);
val |= *p >> b;
nrbits += b;
} else {
switch (bytes) {
case 1:
val = p[0];
break;
case 2:
val = p[0] | ((uint32_t)p[1] << 8);
break;
case 3:
val = p[0] | ((uint32_t)p[1] << 8) |
((uint32_t)p[2] << 16);
break;
case 4:
val = p[0] | ((uint32_t)p[1] << 8) |
((uint32_t)p[2] << 16) |
((uint32_t)p[3] << 24);
break;
}
}
val <<= k;
val >>= k;
b = nrbits & 7;
p += nrbits >> 3;
*addr = p;
*pos = b;
ubifs_assert((val >> nrbits) == 0 || nrbits - b == 32);
return val;
}
/**
* ubifs_pack_pnode - pack all the bit fields of a pnode.
* @c: UBIFS file-system description object
* @buf: buffer into which to pack
* @pnode: pnode to pack
*/
void ubifs_pack_pnode(struct ubifs_info *c, void *buf,
struct ubifs_pnode *pnode)
{
uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
int i, pos = 0;
uint16_t crc;
pack_bits(&addr, &pos, UBIFS_LPT_PNODE, UBIFS_LPT_TYPE_BITS);
if (c->big_lpt)
pack_bits(&addr, &pos, pnode->num, c->pcnt_bits);
for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
pack_bits(&addr, &pos, pnode->lprops[i].free >> 3,
c->space_bits);
pack_bits(&addr, &pos, pnode->lprops[i].dirty >> 3,
c->space_bits);
if (pnode->lprops[i].flags & LPROPS_INDEX)
pack_bits(&addr, &pos, 1, 1);
else
pack_bits(&addr, &pos, 0, 1);
}
crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
c->pnode_sz - UBIFS_LPT_CRC_BYTES);
addr = buf;
pos = 0;
pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
}
/**
* ubifs_pack_nnode - pack all the bit fields of a nnode.
* @c: UBIFS file-system description object
* @buf: buffer into which to pack
* @nnode: nnode to pack
*/
void ubifs_pack_nnode(struct ubifs_info *c, void *buf,
struct ubifs_nnode *nnode)
{
uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
int i, pos = 0;
uint16_t crc;
pack_bits(&addr, &pos, UBIFS_LPT_NNODE, UBIFS_LPT_TYPE_BITS);
if (c->big_lpt)
pack_bits(&addr, &pos, nnode->num, c->pcnt_bits);
for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
int lnum = nnode->nbranch[i].lnum;
if (lnum == 0)
lnum = c->lpt_last + 1;
pack_bits(&addr, &pos, lnum - c->lpt_first, c->lpt_lnum_bits);
pack_bits(&addr, &pos, nnode->nbranch[i].offs,
c->lpt_offs_bits);
}
crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
c->nnode_sz - UBIFS_LPT_CRC_BYTES);
addr = buf;
pos = 0;
pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
}
/**
* ubifs_pack_ltab - pack the LPT's own lprops table.
* @c: UBIFS file-system description object
* @buf: buffer into which to pack
* @ltab: LPT's own lprops table to pack
*/
void ubifs_pack_ltab(struct ubifs_info *c, void *buf,
struct ubifs_lpt_lprops *ltab)
{
uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
int i, pos = 0;
uint16_t crc;
pack_bits(&addr, &pos, UBIFS_LPT_LTAB, UBIFS_LPT_TYPE_BITS);
for (i = 0; i < c->lpt_lebs; i++) {
pack_bits(&addr, &pos, ltab[i].free, c->lpt_spc_bits);
pack_bits(&addr, &pos, ltab[i].dirty, c->lpt_spc_bits);
}
crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
c->ltab_sz - UBIFS_LPT_CRC_BYTES);
addr = buf;
pos = 0;
pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
}
/**
* ubifs_pack_lsave - pack the LPT's save table.
* @c: UBIFS file-system description object
* @buf: buffer into which to pack
* @lsave: LPT's save table to pack
*/
void ubifs_pack_lsave(struct ubifs_info *c, void *buf, int *lsave)
{
uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
int i, pos = 0;
uint16_t crc;
pack_bits(&addr, &pos, UBIFS_LPT_LSAVE, UBIFS_LPT_TYPE_BITS);
for (i = 0; i < c->lsave_cnt; i++)
pack_bits(&addr, &pos, lsave[i], c->lnum_bits);
crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
c->lsave_sz - UBIFS_LPT_CRC_BYTES);
addr = buf;
pos = 0;
pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
}
/**
* ubifs_add_lpt_dirt - add dirty space to LPT LEB properties.
* @c: UBIFS file-system description object
* @lnum: LEB number to which to add dirty space
* @dirty: amount of dirty space to add
*/
void ubifs_add_lpt_dirt(struct ubifs_info *c, int lnum, int dirty)
{
if (!dirty || !lnum)
return;
dbg_lp("LEB %d add %d to %d",
lnum, dirty, c->ltab[lnum - c->lpt_first].dirty);
ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
c->ltab[lnum - c->lpt_first].dirty += dirty;
}
/**
* set_ltab - set LPT LEB properties.
* @c: UBIFS file-system description object
* @lnum: LEB number
* @free: amount of free space
* @dirty: amount of dirty space
*/
static void set_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
{
dbg_lp("LEB %d free %d dirty %d to %d %d",
lnum, c->ltab[lnum - c->lpt_first].free,
c->ltab[lnum - c->lpt_first].dirty, free, dirty);
ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
c->ltab[lnum - c->lpt_first].free = free;
c->ltab[lnum - c->lpt_first].dirty = dirty;
}
/**
* ubifs_add_nnode_dirt - add dirty space to LPT LEB properties.
* @c: UBIFS file-system description object
* @nnode: nnode for which to add dirt
*/
void ubifs_add_nnode_dirt(struct ubifs_info *c, struct ubifs_nnode *nnode)
{
struct ubifs_nnode *np = nnode->parent;
if (np)
ubifs_add_lpt_dirt(c, np->nbranch[nnode->iip].lnum,
c->nnode_sz);
else {
ubifs_add_lpt_dirt(c, c->lpt_lnum, c->nnode_sz);
if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
c->lpt_drty_flgs |= LTAB_DIRTY;
ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
}
}
}
/**
* add_pnode_dirt - add dirty space to LPT LEB properties.
* @c: UBIFS file-system description object
* @pnode: pnode for which to add dirt
*/
static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
{
ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
c->pnode_sz);
}
/**
* calc_nnode_num - calculate nnode number.
* @row: the row in the tree (root is zero)
* @col: the column in the row (leftmost is zero)
*
* The nnode number is a number that uniquely identifies a nnode and can be used
* easily to traverse the tree from the root to that nnode.
*
* This function calculates and returns the nnode number for the nnode at @row
* and @col.
*/
static int calc_nnode_num(int row, int col)
{
int num, bits;
num = 1;
while (row--) {
bits = (col & (UBIFS_LPT_FANOUT - 1));
col >>= UBIFS_LPT_FANOUT_SHIFT;
num <<= UBIFS_LPT_FANOUT_SHIFT;
num |= bits;
}
return num;
}
/**
* calc_nnode_num_from_parent - calculate nnode number.
* @c: UBIFS file-system description object
* @parent: parent nnode
* @iip: index in parent
*
* The nnode number is a number that uniquely identifies a nnode and can be used
* easily to traverse the tree from the root to that nnode.
*
* This function calculates and returns the nnode number based on the parent's
* nnode number and the index in parent.
*/
static int calc_nnode_num_from_parent(const struct ubifs_info *c,
struct ubifs_nnode *parent, int iip)
{
int num, shft;
if (!parent)
return 1;
shft = (c->lpt_hght - parent->level) * UBIFS_LPT_FANOUT_SHIFT;
num = parent->num ^ (1 << shft);
num |= (UBIFS_LPT_FANOUT + iip) << shft;
return num;
}
/**
* calc_pnode_num_from_parent - calculate pnode number.
* @c: UBIFS file-system description object
* @parent: parent nnode
* @iip: index in parent
*
* The pnode number is a number that uniquely identifies a pnode and can be used
* easily to traverse the tree from the root to that pnode.
*
* This function calculates and returns the pnode number based on the parent's
* nnode number and the index in parent.
*/
static int calc_pnode_num_from_parent(const struct ubifs_info *c,
struct ubifs_nnode *parent, int iip)
{
int i, n = c->lpt_hght - 1, pnum = parent->num, num = 0;
for (i = 0; i < n; i++) {
num <<= UBIFS_LPT_FANOUT_SHIFT;
num |= pnum & (UBIFS_LPT_FANOUT - 1);
pnum >>= UBIFS_LPT_FANOUT_SHIFT;
}
num <<= UBIFS_LPT_FANOUT_SHIFT;
num |= iip;
return num;
}
/**
* ubifs_create_dflt_lpt - create default LPT.
* @c: UBIFS file-system description object
* @main_lebs: number of main area LEBs is passed and returned here
* @lpt_first: LEB number of first LPT LEB
* @lpt_lebs: number of LEBs for LPT is passed and returned here
* @big_lpt: use big LPT model is passed and returned here
*
* This function returns %0 on success and a negative error code on failure.
*/
int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
int *lpt_lebs, int *big_lpt)
{
int lnum, err = 0, node_sz, iopos, i, j, cnt, len, alen, row;
int blnum, boffs, bsz, bcnt;
struct ubifs_pnode *pnode = NULL;
struct ubifs_nnode *nnode = NULL;
void *buf = NULL, *p;
struct ubifs_lpt_lprops *ltab = NULL;
int *lsave = NULL;
err = calc_dflt_lpt_geom(c, main_lebs, big_lpt);
if (err)
return err;
*lpt_lebs = c->lpt_lebs;
/* Needed by 'ubifs_pack_nnode()' and 'set_ltab()' */
c->lpt_first = lpt_first;
/* Needed by 'set_ltab()' */
c->lpt_last = lpt_first + c->lpt_lebs - 1;
/* Needed by 'ubifs_pack_lsave()' */
c->main_first = c->leb_cnt - *main_lebs;
lsave = kmalloc(sizeof(int) * c->lsave_cnt, GFP_KERNEL);
pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_KERNEL);
nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_KERNEL);
buf = vmalloc(c->leb_size);
ltab = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
if (!pnode || !nnode || !buf || !ltab || !lsave) {
err = -ENOMEM;
goto out;
}
ubifs_assert(!c->ltab);
c->ltab = ltab; /* Needed by set_ltab */
/* Initialize LPT's own lprops */
for (i = 0; i < c->lpt_lebs; i++) {
ltab[i].free = c->leb_size;
ltab[i].dirty = 0;
ltab[i].tgc = 0;
ltab[i].cmt = 0;
}
lnum = lpt_first;
p = buf;
/* Number of leaf nodes (pnodes) */
cnt = c->pnode_cnt;
/*
* The first pnode contains the LEB properties for the LEBs that contain
* the root inode node and the root index node of the index tree.
*/
node_sz = ALIGN(ubifs_idx_node_sz(c, 1), 8);
iopos = ALIGN(node_sz, c->min_io_size);
pnode->lprops[0].free = c->leb_size - iopos;
pnode->lprops[0].dirty = iopos - node_sz;
pnode->lprops[0].flags = LPROPS_INDEX;
node_sz = UBIFS_INO_NODE_SZ;
iopos = ALIGN(node_sz, c->min_io_size);
pnode->lprops[1].free = c->leb_size - iopos;
pnode->lprops[1].dirty = iopos - node_sz;
for (i = 2; i < UBIFS_LPT_FANOUT; i++)
pnode->lprops[i].free = c->leb_size;
/* Add first pnode */
ubifs_pack_pnode(c, p, pnode);
p += c->pnode_sz;
len = c->pnode_sz;
pnode->num += 1;
/* Reset pnode values for remaining pnodes */
pnode->lprops[0].free = c->leb_size;
pnode->lprops[0].dirty = 0;
pnode->lprops[0].flags = 0;
pnode->lprops[1].free = c->leb_size;
pnode->lprops[1].dirty = 0;
/*
* To calculate the internal node branches, we keep information about
* the level below.
*/
blnum = lnum; /* LEB number of level below */
boffs = 0; /* Offset of level below */
bcnt = cnt; /* Number of nodes in level below */
bsz = c->pnode_sz; /* Size of nodes in level below */
/* Add all remaining pnodes */
for (i = 1; i < cnt; i++) {
if (len + c->pnode_sz > c->leb_size) {
alen = ALIGN(len, c->min_io_size);
set_ltab(c, lnum, c->leb_size - alen, alen - len);
memset(p, 0xff, alen - len);
err = ubifs_leb_change(c, lnum++, buf, alen);
if (err)
goto out;
p = buf;
len = 0;
}
ubifs_pack_pnode(c, p, pnode);
p += c->pnode_sz;
len += c->pnode_sz;
/*
* pnodes are simply numbered left to right starting at zero,
* which means the pnode number can be used easily to traverse
* down the tree to the corresponding pnode.
*/
pnode->num += 1;
}
row = 0;
for (i = UBIFS_LPT_FANOUT; cnt > i; i <<= UBIFS_LPT_FANOUT_SHIFT)
row += 1;
/* Add all nnodes, one level at a time */
while (1) {
/* Number of internal nodes (nnodes) at next level */
cnt = DIV_ROUND_UP(cnt, UBIFS_LPT_FANOUT);
for (i = 0; i < cnt; i++) {
if (len + c->nnode_sz > c->leb_size) {
alen = ALIGN(len, c->min_io_size);
set_ltab(c, lnum, c->leb_size - alen,
alen - len);
memset(p, 0xff, alen - len);
err = ubifs_leb_change(c, lnum++, buf, alen);
if (err)
goto out;
p = buf;
len = 0;
}
/* Only 1 nnode at this level, so it is the root */
if (cnt == 1) {
c->lpt_lnum = lnum;
c->lpt_offs = len;
}
/* Set branches to the level below */
for (j = 0; j < UBIFS_LPT_FANOUT; j++) {
if (bcnt) {
if (boffs + bsz > c->leb_size) {
blnum += 1;
boffs = 0;
}
nnode->nbranch[j].lnum = blnum;
nnode->nbranch[j].offs = boffs;
boffs += bsz;
bcnt--;
} else {
nnode->nbranch[j].lnum = 0;
nnode->nbranch[j].offs = 0;
}
}
nnode->num = calc_nnode_num(row, i);
ubifs_pack_nnode(c, p, nnode);
p += c->nnode_sz;
len += c->nnode_sz;
}
/* Only 1 nnode at this level, so it is the root */
if (cnt == 1)
break;
/* Update the information about the level below */
bcnt = cnt;
bsz = c->nnode_sz;
row -= 1;
}
if (*big_lpt) {
/* Need to add LPT's save table */
if (len + c->lsave_sz > c->leb_size) {
alen = ALIGN(len, c->min_io_size);
set_ltab(c, lnum, c->leb_size - alen, alen - len);
memset(p, 0xff, alen - len);
err = ubifs_leb_change(c, lnum++, buf, alen);
if (err)
goto out;
p = buf;
len = 0;
}
c->lsave_lnum = lnum;
c->lsave_offs = len;
for (i = 0; i < c->lsave_cnt && i < *main_lebs; i++)
lsave[i] = c->main_first + i;
for (; i < c->lsave_cnt; i++)
lsave[i] = c->main_first;
ubifs_pack_lsave(c, p, lsave);
p += c->lsave_sz;
len += c->lsave_sz;
}
/* Need to add LPT's own LEB properties table */
if (len + c->ltab_sz > c->leb_size) {
alen = ALIGN(len, c->min_io_size);
set_ltab(c, lnum, c->leb_size - alen, alen - len);
memset(p, 0xff, alen - len);
err = ubifs_leb_change(c, lnum++, buf, alen);
if (err)
goto out;
p = buf;
len = 0;
}
c->ltab_lnum = lnum;
c->ltab_offs = len;
/* Update ltab before packing it */
len += c->ltab_sz;
alen = ALIGN(len, c->min_io_size);
set_ltab(c, lnum, c->leb_size - alen, alen - len);
ubifs_pack_ltab(c, p, ltab);
p += c->ltab_sz;
/* Write remaining buffer */
memset(p, 0xff, alen - len);
err = ubifs_leb_change(c, lnum, buf, alen);
if (err)
goto out;
c->nhead_lnum = lnum;
c->nhead_offs = ALIGN(len, c->min_io_size);
dbg_lp("space_bits %d", c->space_bits);
dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
dbg_lp("pcnt_bits %d", c->pcnt_bits);
dbg_lp("lnum_bits %d", c->lnum_bits);
dbg_lp("pnode_sz %d", c->pnode_sz);
dbg_lp("nnode_sz %d", c->nnode_sz);
dbg_lp("ltab_sz %d", c->ltab_sz);
dbg_lp("lsave_sz %d", c->lsave_sz);
dbg_lp("lsave_cnt %d", c->lsave_cnt);
dbg_lp("lpt_hght %d", c->lpt_hght);
dbg_lp("big_lpt %d", c->big_lpt);
dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
if (c->big_lpt)
dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
out:
c->ltab = NULL;
kfree(lsave);
vfree(ltab);
vfree(buf);
kfree(nnode);
kfree(pnode);
return err;
}
/**
* update_cats - add LEB properties of a pnode to LEB category lists and heaps.
* @c: UBIFS file-system description object
* @pnode: pnode
*
* When a pnode is loaded into memory, the LEB properties it contains are added,
* by this function, to the LEB category lists and heaps.
*/
static void update_cats(struct ubifs_info *c, struct ubifs_pnode *pnode)
{
int i;
for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
int cat = pnode->lprops[i].flags & LPROPS_CAT_MASK;
int lnum = pnode->lprops[i].lnum;
if (!lnum)
return;
ubifs_add_to_cat(c, &pnode->lprops[i], cat);
}
}
/**
* replace_cats - add LEB properties of a pnode to LEB category lists and heaps.
* @c: UBIFS file-system description object
* @old_pnode: pnode copied
* @new_pnode: pnode copy
*
* During commit it is sometimes necessary to copy a pnode
* (see dirty_cow_pnode). When that happens, references in
* category lists and heaps must be replaced. This function does that.
*/
static void replace_cats(struct ubifs_info *c, struct ubifs_pnode *old_pnode,
struct ubifs_pnode *new_pnode)
{
int i;
for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
if (!new_pnode->lprops[i].lnum)
return;
ubifs_replace_cat(c, &old_pnode->lprops[i],
&new_pnode->lprops[i]);
}
}
/**
* check_lpt_crc - check LPT node crc is correct.
* @c: UBIFS file-system description object
* @buf: buffer containing node
* @len: length of node
*
* This function returns %0 on success and a negative error code on failure.
*/
static int check_lpt_crc(void *buf, int len)
{
int pos = 0;
uint8_t *addr = buf;
uint16_t crc, calc_crc;
crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS);
calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
len - UBIFS_LPT_CRC_BYTES);
if (crc != calc_crc) {
ubifs_err("invalid crc in LPT node: crc %hx calc %hx", crc,
calc_crc);
dump_stack();
return -EINVAL;
}
return 0;
}
/**
* check_lpt_type - check LPT node type is correct.
* @c: UBIFS file-system description object
* @addr: address of type bit field is passed and returned updated here
* @pos: position of type bit field is passed and returned updated here
* @type: expected type
*
* This function returns %0 on success and a negative error code on failure.
*/
static int check_lpt_type(uint8_t **addr, int *pos, int type)
{
int node_type;
node_type = ubifs_unpack_bits(addr, pos, UBIFS_LPT_TYPE_BITS);
if (node_type != type) {
ubifs_err("invalid type (%d) in LPT node type %d", node_type,
type);
dump_stack();
return -EINVAL;
}
return 0;
}
/**
* unpack_pnode - unpack a pnode.
* @c: UBIFS file-system description object
* @buf: buffer containing packed pnode to unpack
* @pnode: pnode structure to fill
*
* This function returns %0 on success and a negative error code on failure.
*/
static int unpack_pnode(const struct ubifs_info *c, void *buf,
struct ubifs_pnode *pnode)
{
uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
int i, pos = 0, err;
err = check_lpt_type(&addr, &pos, UBIFS_LPT_PNODE);
if (err)
return err;
if (c->big_lpt)
pnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
struct ubifs_lprops * const lprops = &pnode->lprops[i];
lprops->free = ubifs_unpack_bits(&addr, &pos, c->space_bits);
lprops->free <<= 3;
lprops->dirty = ubifs_unpack_bits(&addr, &pos, c->space_bits);
lprops->dirty <<= 3;
if (ubifs_unpack_bits(&addr, &pos, 1))
lprops->flags = LPROPS_INDEX;
else
lprops->flags = 0;
lprops->flags |= ubifs_categorize_lprops(c, lprops);
}
err = check_lpt_crc(buf, c->pnode_sz);
return err;
}
/**
* ubifs_unpack_nnode - unpack a nnode.
* @c: UBIFS file-system description object
* @buf: buffer containing packed nnode to unpack
* @nnode: nnode structure to fill
*
* This function returns %0 on success and a negative error code on failure.
*/
int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf,