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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 "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;
- }
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