--- /dev/null
+/*
+ * 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;
+}
Code Review / kvmfornfv.git / blobdiff