/*
* 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 "crc16.h"
#include <linux/math64.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;
}
/**
* 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_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;
}
/**
* 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_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;
}
/**
* 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);
dbg_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);
dbg_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,
struct ubifs_nnode *nnode)
{
uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
int i, pos = 0, err;
err = check_lpt_type(&addr, &pos, UBIFS_LPT_NNODE);
if (err)
return err;
if (c->big_lpt)
nnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
int lnum;
lnum = ubifs_unpack_bits(&addr, &pos, c->lpt_lnum_bits) +
c->lpt_first;
if (lnum == c->lpt_last + 1)
lnum = 0;
nnode->nbranch[i].lnum = lnum;
nnode->nbranch[i].offs = ubifs_unpack_bits(&addr, &pos,
c->lpt_offs_bits);
}
err = check_lpt_crc(buf, c->nnode_sz);
return err;
}
/**
* unpack_ltab - unpack the LPT's own lprops table.
* @c: UBIFS file-system description object
* @buf: buffer from which to unpack
*
* This function returns %0 on success and a negative error code on failure.
*/
static int unpack_ltab(const struct ubifs_info *c, void *buf)
{
uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
int i, pos = 0, err;
err = check_lpt_type(&addr, &pos, UBIFS_LPT_LTAB);
if (err)
return err;
for (i = 0; i < c->lpt_lebs; i++) {
int free = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
int dirty = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
if (free < 0 || free > c->leb_size || dirty < 0 ||
dirty > c->leb_size || free + dirty > c->leb_size)
return -EINVAL;
c->ltab[i].free = free;
c->ltab[i].dirty = dirty;
c->ltab[i].tgc = 0;
c->ltab[i].cmt = 0;
}
err = check_lpt_crc(buf, c->ltab_sz);
return err;
}
/**
* validate_nnode - validate a nnode.
* @c: UBIFS file-system description object
* @nnode: nnode to validate
* @parent: parent nnode (or NULL for the root nnode)
* @iip: index in parent
*
* This function returns %0 on success and a negative error code on failure.
*/
static int validate_nnode(const struct ubifs_info *c, struct ubifs_nnode *nnode,
struct ubifs_nnode *parent, int iip)
{
int i, lvl, max_offs;
if (c->big_lpt) {
int num = calc_nnode_num_from_parent(c, parent, iip);
if (nnode->num != num)
return -EINVAL;
}
lvl = parent ? parent->level - 1 : c->lpt_hght;
if (lvl < 1)
return -EINVAL;
if (lvl == 1)
max_offs = c->leb_size - c->pnode_sz;
else
max_offs = c->leb_size - c->nnode_sz;
for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
int lnum = nnode->nbranch[i].lnum;
int offs = nnode->nbranch[i].offs;
if (lnum == 0) {
if (offs != 0)
return -EINVAL;
continue;
}
if (lnum < c->lpt_first || lnum > c->lpt_last)
return -EINVAL;
if (offs < 0 || offs > max_offs)
return -EINVAL;
}
return 0;
}
/**
* validate_pnode - validate a pnode.
* @c: UBIFS file-system description object
* @pnode: pnode to validate
* @parent: parent nnode
* @iip: index in parent
*
* This function returns %0 on success and a negative error code on failure.
*/
static int validate_pnode(const struct ubifs_info *c, struct ubifs_pnode *pnode,
struct ubifs_nnode *parent, int iip)
{
int i;
if (c->big_lpt) {
int num = calc_pnode_num_from_parent(c, parent, iip);
if (pnode->num != num)
return -EINVAL;
}
for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
int free = pnode->lprops[i].free;
int dirty = pnode->lprops[i].dirty;
if (free < 0 || free > c->leb_size || free % c->min_io_size ||
(free & 7))
return -EINVAL;
if (dirty < 0 || dirty > c->leb_size || (dirty & 7))
return -EINVAL;
if (dirty + free > c->leb_size)
return -EINVAL;
}
return 0;
}
/**
* set_pnode_lnum - set LEB numbers on a pnode.
* @c: UBIFS file-system description object
* @pnode: pnode to update
*
* This function calculates the LEB numbers for the LEB properties it contains
* based on the pnode number.
*/
static void set_pnode_lnum(const struct ubifs_info *c,
struct ubifs_pnode *pnode)
{
int i, lnum;
lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + c->main_first;
for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
if (lnum >= c->leb_cnt)
return;
pnode->lprops[i].lnum = lnum++;
}
}
/**
* ubifs_read_nnode - read a nnode from flash and link it to the tree in memory.
* @c: UBIFS file-system description object
* @parent: parent nnode (or NULL for the root)
* @iip: index in parent
*
* This function returns %0 on success and a negative error code on failure.
*/
int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
{
struct ubifs_nbranch *branch = NULL;
struct ubifs_nnode *nnode = NULL;
void *buf = c->lpt_nod_buf;
int err, lnum, offs;
if (parent) {
branch = &parent->nbranch[iip];
lnum = branch->lnum;
offs = branch->offs;
} else {
lnum = c->lpt_lnum;
offs = c->lpt_offs;
}
nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
if (!nnode) {
err = -ENOMEM;
goto out;
}
if (lnum == 0) {
/*
* This nnode was not written which just means that the LEB
* properties in the subtree below it describe empty LEBs. We
* make the nnode as though we had read it, which in fact means
* doing almost nothing.
*/
if (c->big_lpt)
nnode->num = calc_nnode_num_from_parent(c, parent, iip);
} else {
err = ubi_read(c->ubi, lnum, buf, offs, c->nnode_sz);
if (err)
goto out;
err = ubifs_unpack_nnode(c, buf, nnode);
if (err)
goto out;
}
err = validate_nnode(c, nnode, parent, iip);
if (err)
goto out;
if (!c->big_lpt)
nnode->num = calc_nnode_num_from_parent(c, parent, iip);
if (parent) {
branch->nnode = nnode;
nnode->level = parent->level - 1;
} else {
c->nroot = nnode;
nnode->level = c->lpt_hght;
}
nnode->parent = parent;
nnode->iip = iip;
return 0;
out:
ubifs_err("error %d reading nnode at %d:%d", err, lnum, offs);
kfree(nnode);
return err;
}
/**
* read_pnode - read a pnode from flash and link it to the tree in memory.
* @c: UBIFS file-system description object
* @parent: parent nnode
* @iip: index in parent
*
* This function returns %0 on success and a negative error code on failure.
*/
static int read_pnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
{
struct ubifs_nbranch *branch;
struct ubifs_pnode *pnode = NULL;
void *buf = c->lpt_nod_buf;
int err, lnum, offs;
branch = &parent->nbranch[iip];
lnum = branch->lnum;
offs = branch->offs;
pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
if (!pnode) {
err = -ENOMEM;
goto out;
}
if (lnum == 0) {
/*
* This pnode was not written which just means that the LEB
* properties in it describe empty LEBs. We make the pnode as
* though we had read it.
*/
int i;
if (c->big_lpt)
pnode->num = calc_pnode_num_from_parent(c, parent, iip);
for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
struct ubifs_lprops * const lprops = &pnode->lprops[i];
lprops->free = c->leb_size;
lprops->flags = ubifs_categorize_lprops(c, lprops);
}
} else {
err = ubi_read(c->ubi, lnum, buf, offs, c->pnode_sz);
if (err)
goto out;
err = unpack_pnode(c, buf, pnode);
if (err)
goto out;
}
err = validate_pnode(c, pnode, parent, iip);
if (err)
goto out;
if (!c->big_lpt)
pnode->num = calc_pnode_num_from_parent(c, parent, iip);
branch->pnode = pnode;
pnode->parent = parent;
pnode->iip = iip;
set_pnode_lnum(c, pnode);
c->pnodes_have += 1;
return 0;
out:
ubifs_err("error %d reading pnode at %d:%d", err, lnum, offs);
dbg_dump_pnode(c, pnode, parent, iip);
dbg_msg("calc num: %d", calc_pnode_num_from_parent(c, parent, iip));
kfree(pnode);
return err;
}
/**
* read_ltab - read LPT's own lprops table.
* @c: UBIFS file-system description object
*
* This function returns %0 on success and a negative error code on failure.
*/
static int read_ltab(struct ubifs_info *c)
{
int err;
void *buf;
buf = vmalloc(c->ltab_sz);
if (!buf)
return -ENOMEM;
err = ubi_read(c->ubi, c->ltab_lnum, buf, c->ltab_offs, c->ltab_sz);
if (err)
goto out;
err = unpack_ltab(c, buf);
out:
vfree(buf);
return err;
}
/**
* ubifs_get_nnode - get a nnode.
* @c: UBIFS file-system description object
* @parent: parent nnode (or NULL for the root)
* @iip: index in parent
*
* This function returns a pointer to the nnode on success or a negative error
* code on failure.
*/
struct ubifs_nnode *ubifs_get_nnode(struct ubifs_info *c,
struct ubifs_nnode *parent, int iip)
{
struct ubifs_nbranch *branch;
struct ubifs_nnode *nnode;
int err;
branch = &parent->nbranch[iip];
nnode = branch->nnode;
if (nnode)
return nnode;
err = ubifs_read_nnode(c, parent, iip);
if (err)
return ERR_PTR(err);
return branch->nnode;
}
/**
* ubifs_get_pnode - get a pnode.
* @c: UBIFS file-system description object
* @parent: parent nnode
* @iip: index in parent
*
* This function returns a pointer to the pnode on success or a negative error
* code on failure.
*/
struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c,
struct ubifs_nnode *parent, int iip)
{
struct ubifs_nbranch *branch;
struct ubifs_pnode *pnode;
int err;
branch = &parent->nbranch[iip];
pnode = branch->pnode;
if (pnode)
return pnode;
err = read_pnode(c, parent, iip);
if (err)
return ERR_PTR(err);
update_cats(c, branch->pnode);
return branch->pnode;
}
/**
* ubifs_lpt_lookup - lookup LEB properties in the LPT.
* @c: UBIFS file-system description object
* @lnum: LEB number to lookup
*
* This function returns a pointer to the LEB properties on success or a
* negative error code on failure.
*/
struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum)
{
int err, i, h, iip, shft;
struct ubifs_nnode *nnode;
struct ubifs_pnode *pnode;
if (!c->nroot) {
err = ubifs_read_nnode(c, NULL, 0);
if (err)
return ERR_PTR(err);
}
nnode = c->nroot;
i = lnum - c->main_first;
shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
for (h = 1; h < c->lpt_hght; h++) {
iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
shft -= UBIFS_LPT_FANOUT_SHIFT;
nnode = ubifs_get_nnode(c, nnode, iip);
if (IS_ERR(nnode))
return ERR_PTR(PTR_ERR(nnode));
}
iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
shft -= UBIFS_LPT_FANOUT_SHIFT;
pnode = ubifs_get_pnode(c, nnode, iip);
if (IS_ERR(pnode))
return ERR_PTR(PTR_ERR(pnode));
iip = (i & (UBIFS_LPT_FANOUT - 1));
dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
pnode->lprops[iip].free, pnode->lprops[iip].dirty,
pnode->lprops[iip].flags);
return &pnode->lprops[iip];
}
/**
* dirty_cow_nnode - ensure a nnode is not being committed.
* @c: UBIFS file-system description object
* @nnode: nnode to check
*
* Returns dirtied nnode on success or negative error code on failure.
*/
static struct ubifs_nnode *dirty_cow_nnode(struct ubifs_info *c,
struct ubifs_nnode *nnode)
{
struct ubifs_nnode *n;
int i;
if (!test_bit(COW_CNODE, &nnode->flags)) {
/* nnode is not being committed */
if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
c->dirty_nn_cnt += 1;
ubifs_add_nnode_dirt(c, nnode);
}
return nnode;
}
/* nnode is being committed, so copy it */
n = kmalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
if (unlikely(!n))
return ERR_PTR(-ENOMEM);
memcpy(n, nnode, sizeof(struct ubifs_nnode));
n->cnext = NULL;
__set_bit(DIRTY_CNODE, &n->flags);
__clear_bit(COW_CNODE, &n->flags);
/* The children now have new parent */
for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
struct ubifs_nbranch *branch = &n->nbranch[i];
if (branch->cnode)
branch->cnode->parent = n;
}
ubifs_assert(!test_bit(OBSOLETE_CNODE, &nnode->flags));
__set_bit(OBSOLETE_CNODE, &nnode->flags);
c->dirty_nn_cnt += 1;
ubifs_add_nnode_dirt(c, nnode);
if (nnode->parent)
nnode->parent->nbranch[n->iip].nnode = n;
else
c->nroot = n;
return n;
}
/**
* dirty_cow_pnode - ensure a pnode is not being committed.
* @c: UBIFS file-system description object
* @pnode: pnode to check
*
* Returns dirtied pnode on success or negative error code on failure.
*/
static struct ubifs_pnode *dirty_cow_pnode(struct ubifs_info *c,
struct ubifs_pnode *pnode)
{
struct ubifs_pnode *p;
if (!test_bit(COW_CNODE, &pnode->flags)) {
/* pnode is not being committed */
if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
c->dirty_pn_cnt += 1;
add_pnode_dirt(c, pnode);
}
return pnode;
}
/* pnode is being committed, so copy it */
p = kmalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
if (unlikely(!p))
return ERR_PTR(-ENOMEM);
memcpy(p, pnode, sizeof(struct ubifs_pnode));
p->cnext = NULL;
__set_bit(DIRTY_CNODE, &p->flags);
__clear_bit(COW_CNODE, &p->flags);
replace_cats(c, pnode, p);
ubifs_assert(!test_bit(OBSOLETE_CNODE, &pnode->flags));
__set_bit(OBSOLETE_CNODE, &pnode->flags);
c->dirty_pn_cnt += 1;
add_pnode_dirt(c, pnode);
pnode->parent->nbranch[p->iip].pnode = p;
return p;
}
/**
* ubifs_lpt_lookup_dirty - lookup LEB properties in the LPT.
* @c: UBIFS file-system description object
* @lnum: LEB number to lookup
*
* This function returns a pointer to the LEB properties on success or a
* negative error code on failure.
*/
struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum)
{
int err, i, h, iip, shft;
struct ubifs_nnode *nnode;
struct ubifs_pnode *pnode;
if (!c->nroot) {
err = ubifs_read_nnode(c, NULL, 0);
if (err)
return ERR_PTR(err);
}
nnode = c->nroot;
nnode = dirty_cow_nnode(c, nnode);
if (IS_ERR(nnode))
return ERR_PTR(PTR_ERR(nnode));
i = lnum - c->main_first;
shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
for (h = 1; h < c->lpt_hght; h++) {
iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
shft -= UBIFS_LPT_FANOUT_SHIFT;
nnode = ubifs_get_nnode(c, nnode, iip);
if (IS_ERR(nnode))
return ERR_PTR(PTR_ERR(nnode));
nnode = dirty_cow_nnode(c, nnode);
if (IS_ERR(nnode))
return ERR_PTR(PTR_ERR(nnode));
}
iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
shft -= UBIFS_LPT_FANOUT_SHIFT;
pnode = ubifs_get_pnode(c, nnode, iip);
if (IS_ERR(pnode))
return ERR_PTR(PTR_ERR(pnode));
pnode = dirty_cow_pnode(c, pnode);
if (IS_ERR(pnode))
return ERR_PTR(PTR_ERR(pnode));
iip = (i & (UBIFS_LPT_FANOUT - 1));
dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
pnode->lprops[iip].free, pnode->lprops[iip].dirty,
pnode->lprops[iip].flags);
ubifs_assert(test_bit(DIRTY_CNODE, &pnode->flags));
return &pnode->lprops[iip];
}
/**
* lpt_init_rd - initialize the LPT for reading.
* @c: UBIFS file-system description object
*
* This function returns %0 on success and a negative error code on failure.
*/
static int lpt_init_rd(struct ubifs_info *c)
{
int err, i;
c->ltab = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
if (!c->ltab)
return -ENOMEM;
i = max_t(int, c->nnode_sz, c->pnode_sz);
c->lpt_nod_buf = kmalloc(i, GFP_KERNEL);
if (!c->lpt_nod_buf)
return -ENOMEM;
for (i = 0; i < LPROPS_HEAP_CNT; i++) {
c->lpt_heap[i].arr = kmalloc(sizeof(void *) * LPT_HEAP_SZ,
GFP_KERNEL);
if (!c->lpt_heap[i].arr)
return -ENOMEM;
c->lpt_heap[i].cnt = 0;
c->lpt_heap[i].max_cnt = LPT_HEAP_SZ;
}
c->dirty_idx.arr = kmalloc(sizeof(void *) * LPT_HEAP_SZ, GFP_KERNEL);
if (!c->dirty_idx.arr)
return -ENOMEM;
c->dirty_idx.cnt = 0;
c->dirty_idx.max_cnt = LPT_HEAP_SZ;
err = read_ltab(c);
if (err)
return err;
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);
return 0;
}
/**
* ubifs_lpt_init - initialize the LPT.
* @c: UBIFS file-system description object
* @rd: whether to initialize lpt for reading
* @wr: whether to initialize lpt for writing
*
* For mounting 'rw', @rd and @wr are both true. For mounting 'ro', @rd is true
* and @wr is false. For mounting from 'ro' to 'rw', @rd is false and @wr is
* true.
*
* This function returns %0 on success and a negative error code on failure.
*/
int ubifs_lpt_init(struct ubifs_info *c, int rd, int wr)
{
int err;
if (rd) {
err = lpt_init_rd(c);
if (err)
return err;
}
return 0;
}
