/* * 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; }