![Sascha Hauer](/assets/img/avatar_default.png)
With this patch the hashes over the index nodes stored in the tree node cache are written to flash and are checked when read back from flash. The hash of the root index node is stored in the master node. During journal replay the hashes are regenerated from the read nodes and stored in the tree node cache. This means the nodes must previously be authenticated by other means. This is done in a later patch. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Richard Weinberger <richard@nod.at>
1104 lines
28 KiB
C
1104 lines
28 KiB
C
/*
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* This file is part of UBIFS.
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*
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* Copyright (C) 2006-2008 Nokia Corporation.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc., 51
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* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Authors: Adrian Hunter
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* Artem Bityutskiy (Битюцкий Артём)
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*/
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/* This file implements TNC functions for committing */
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#include <linux/random.h>
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#include "ubifs.h"
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/**
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* make_idx_node - make an index node for fill-the-gaps method of TNC commit.
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* @c: UBIFS file-system description object
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* @idx: buffer in which to place new index node
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* @znode: znode from which to make new index node
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* @lnum: LEB number where new index node will be written
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* @offs: offset where new index node will be written
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* @len: length of new index node
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*/
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static int make_idx_node(struct ubifs_info *c, struct ubifs_idx_node *idx,
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struct ubifs_znode *znode, int lnum, int offs, int len)
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{
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struct ubifs_znode *zp;
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u8 hash[UBIFS_HASH_ARR_SZ];
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int i, err;
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/* Make index node */
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idx->ch.node_type = UBIFS_IDX_NODE;
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idx->child_cnt = cpu_to_le16(znode->child_cnt);
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idx->level = cpu_to_le16(znode->level);
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for (i = 0; i < znode->child_cnt; i++) {
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struct ubifs_branch *br = ubifs_idx_branch(c, idx, i);
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struct ubifs_zbranch *zbr = &znode->zbranch[i];
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key_write_idx(c, &zbr->key, &br->key);
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br->lnum = cpu_to_le32(zbr->lnum);
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br->offs = cpu_to_le32(zbr->offs);
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br->len = cpu_to_le32(zbr->len);
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ubifs_copy_hash(c, zbr->hash, ubifs_branch_hash(c, br));
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if (!zbr->lnum || !zbr->len) {
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ubifs_err(c, "bad ref in znode");
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ubifs_dump_znode(c, znode);
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if (zbr->znode)
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ubifs_dump_znode(c, zbr->znode);
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return -EINVAL;
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}
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}
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ubifs_prepare_node(c, idx, len, 0);
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ubifs_node_calc_hash(c, idx, hash);
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znode->lnum = lnum;
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znode->offs = offs;
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znode->len = len;
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err = insert_old_idx_znode(c, znode);
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/* Update the parent */
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zp = znode->parent;
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if (zp) {
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struct ubifs_zbranch *zbr;
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zbr = &zp->zbranch[znode->iip];
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zbr->lnum = lnum;
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zbr->offs = offs;
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zbr->len = len;
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ubifs_copy_hash(c, hash, zbr->hash);
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} else {
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c->zroot.lnum = lnum;
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c->zroot.offs = offs;
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c->zroot.len = len;
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ubifs_copy_hash(c, hash, c->zroot.hash);
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}
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c->calc_idx_sz += ALIGN(len, 8);
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atomic_long_dec(&c->dirty_zn_cnt);
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ubifs_assert(c, ubifs_zn_dirty(znode));
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ubifs_assert(c, ubifs_zn_cow(znode));
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/*
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* Note, unlike 'write_index()' we do not add memory barriers here
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* because this function is called with @c->tnc_mutex locked.
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*/
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__clear_bit(DIRTY_ZNODE, &znode->flags);
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__clear_bit(COW_ZNODE, &znode->flags);
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return err;
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}
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/**
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* fill_gap - make index nodes in gaps in dirty index LEBs.
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* @c: UBIFS file-system description object
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* @lnum: LEB number that gap appears in
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* @gap_start: offset of start of gap
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* @gap_end: offset of end of gap
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* @dirt: adds dirty space to this
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*
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* This function returns the number of index nodes written into the gap.
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*/
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static int fill_gap(struct ubifs_info *c, int lnum, int gap_start, int gap_end,
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int *dirt)
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{
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int len, gap_remains, gap_pos, written, pad_len;
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ubifs_assert(c, (gap_start & 7) == 0);
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ubifs_assert(c, (gap_end & 7) == 0);
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ubifs_assert(c, gap_end >= gap_start);
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gap_remains = gap_end - gap_start;
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if (!gap_remains)
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return 0;
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gap_pos = gap_start;
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written = 0;
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while (c->enext) {
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len = ubifs_idx_node_sz(c, c->enext->child_cnt);
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if (len < gap_remains) {
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struct ubifs_znode *znode = c->enext;
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const int alen = ALIGN(len, 8);
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int err;
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ubifs_assert(c, alen <= gap_remains);
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err = make_idx_node(c, c->ileb_buf + gap_pos, znode,
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lnum, gap_pos, len);
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if (err)
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return err;
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gap_remains -= alen;
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gap_pos += alen;
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c->enext = znode->cnext;
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if (c->enext == c->cnext)
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c->enext = NULL;
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written += 1;
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} else
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break;
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}
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if (gap_end == c->leb_size) {
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c->ileb_len = ALIGN(gap_pos, c->min_io_size);
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/* Pad to end of min_io_size */
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pad_len = c->ileb_len - gap_pos;
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} else
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/* Pad to end of gap */
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pad_len = gap_remains;
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dbg_gc("LEB %d:%d to %d len %d nodes written %d wasted bytes %d",
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lnum, gap_start, gap_end, gap_end - gap_start, written, pad_len);
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ubifs_pad(c, c->ileb_buf + gap_pos, pad_len);
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*dirt += pad_len;
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return written;
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}
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/**
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* find_old_idx - find an index node obsoleted since the last commit start.
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* @c: UBIFS file-system description object
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* @lnum: LEB number of obsoleted index node
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* @offs: offset of obsoleted index node
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*
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* Returns %1 if found and %0 otherwise.
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*/
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static int find_old_idx(struct ubifs_info *c, int lnum, int offs)
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{
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struct ubifs_old_idx *o;
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struct rb_node *p;
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p = c->old_idx.rb_node;
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while (p) {
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o = rb_entry(p, struct ubifs_old_idx, rb);
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if (lnum < o->lnum)
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p = p->rb_left;
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else if (lnum > o->lnum)
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p = p->rb_right;
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else if (offs < o->offs)
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p = p->rb_left;
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else if (offs > o->offs)
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p = p->rb_right;
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else
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return 1;
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}
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return 0;
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}
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/**
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* is_idx_node_in_use - determine if an index node can be overwritten.
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* @c: UBIFS file-system description object
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* @key: key of index node
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* @level: index node level
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* @lnum: LEB number of index node
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* @offs: offset of index node
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*
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* If @key / @lnum / @offs identify an index node that was not part of the old
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* index, then this function returns %0 (obsolete). Else if the index node was
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* part of the old index but is now dirty %1 is returned, else if it is clean %2
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* is returned. A negative error code is returned on failure.
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*/
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static int is_idx_node_in_use(struct ubifs_info *c, union ubifs_key *key,
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int level, int lnum, int offs)
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{
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int ret;
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ret = is_idx_node_in_tnc(c, key, level, lnum, offs);
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if (ret < 0)
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return ret; /* Error code */
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if (ret == 0)
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if (find_old_idx(c, lnum, offs))
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return 1;
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return ret;
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}
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/**
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* layout_leb_in_gaps - layout index nodes using in-the-gaps method.
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* @c: UBIFS file-system description object
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* @p: return LEB number here
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*
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* This function lays out new index nodes for dirty znodes using in-the-gaps
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* method of TNC commit.
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* This function merely puts the next znode into the next gap, making no attempt
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* to try to maximise the number of znodes that fit.
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* This function returns the number of index nodes written into the gaps, or a
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* negative error code on failure.
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*/
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static int layout_leb_in_gaps(struct ubifs_info *c, int *p)
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{
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struct ubifs_scan_leb *sleb;
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struct ubifs_scan_node *snod;
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int lnum, dirt = 0, gap_start, gap_end, err, written, tot_written;
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tot_written = 0;
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/* Get an index LEB with lots of obsolete index nodes */
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lnum = ubifs_find_dirty_idx_leb(c);
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if (lnum < 0)
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/*
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* There also may be dirt in the index head that could be
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* filled, however we do not check there at present.
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*/
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return lnum; /* Error code */
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*p = lnum;
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dbg_gc("LEB %d", lnum);
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/*
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* Scan the index LEB. We use the generic scan for this even though
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* it is more comprehensive and less efficient than is needed for this
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* purpose.
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*/
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sleb = ubifs_scan(c, lnum, 0, c->ileb_buf, 0);
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c->ileb_len = 0;
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if (IS_ERR(sleb))
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return PTR_ERR(sleb);
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gap_start = 0;
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list_for_each_entry(snod, &sleb->nodes, list) {
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struct ubifs_idx_node *idx;
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int in_use, level;
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ubifs_assert(c, snod->type == UBIFS_IDX_NODE);
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idx = snod->node;
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key_read(c, ubifs_idx_key(c, idx), &snod->key);
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level = le16_to_cpu(idx->level);
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/* Determine if the index node is in use (not obsolete) */
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in_use = is_idx_node_in_use(c, &snod->key, level, lnum,
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snod->offs);
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if (in_use < 0) {
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ubifs_scan_destroy(sleb);
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return in_use; /* Error code */
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}
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if (in_use) {
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if (in_use == 1)
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dirt += ALIGN(snod->len, 8);
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/*
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* The obsolete index nodes form gaps that can be
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* overwritten. This gap has ended because we have
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* found an index node that is still in use
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* i.e. not obsolete
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*/
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gap_end = snod->offs;
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/* Try to fill gap */
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written = fill_gap(c, lnum, gap_start, gap_end, &dirt);
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if (written < 0) {
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ubifs_scan_destroy(sleb);
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return written; /* Error code */
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}
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tot_written += written;
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gap_start = ALIGN(snod->offs + snod->len, 8);
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}
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}
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ubifs_scan_destroy(sleb);
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c->ileb_len = c->leb_size;
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gap_end = c->leb_size;
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/* Try to fill gap */
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written = fill_gap(c, lnum, gap_start, gap_end, &dirt);
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if (written < 0)
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return written; /* Error code */
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tot_written += written;
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if (tot_written == 0) {
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struct ubifs_lprops lp;
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dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written);
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err = ubifs_read_one_lp(c, lnum, &lp);
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if (err)
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return err;
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if (lp.free == c->leb_size) {
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/*
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* We must have snatched this LEB from the idx_gc list
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* so we need to correct the free and dirty space.
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*/
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err = ubifs_change_one_lp(c, lnum,
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c->leb_size - c->ileb_len,
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dirt, 0, 0, 0);
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if (err)
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return err;
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}
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return 0;
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}
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err = ubifs_change_one_lp(c, lnum, c->leb_size - c->ileb_len, dirt,
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0, 0, 0);
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if (err)
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return err;
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err = ubifs_leb_change(c, lnum, c->ileb_buf, c->ileb_len);
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if (err)
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return err;
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dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written);
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return tot_written;
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}
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/**
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* get_leb_cnt - calculate the number of empty LEBs needed to commit.
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* @c: UBIFS file-system description object
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* @cnt: number of znodes to commit
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*
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* This function returns the number of empty LEBs needed to commit @cnt znodes
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* to the current index head. The number is not exact and may be more than
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* needed.
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*/
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static int get_leb_cnt(struct ubifs_info *c, int cnt)
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{
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int d;
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/* Assume maximum index node size (i.e. overestimate space needed) */
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cnt -= (c->leb_size - c->ihead_offs) / c->max_idx_node_sz;
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if (cnt < 0)
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cnt = 0;
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d = c->leb_size / c->max_idx_node_sz;
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return DIV_ROUND_UP(cnt, d);
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}
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/**
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* layout_in_gaps - in-the-gaps method of committing TNC.
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* @c: UBIFS file-system description object
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* @cnt: number of dirty znodes to commit.
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*
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* This function lays out new index nodes for dirty znodes using in-the-gaps
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* method of TNC commit.
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*
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* This function returns %0 on success and a negative error code on failure.
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*/
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static int layout_in_gaps(struct ubifs_info *c, int cnt)
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{
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int err, leb_needed_cnt, written, *p;
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dbg_gc("%d znodes to write", cnt);
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c->gap_lebs = kmalloc_array(c->lst.idx_lebs + 1, sizeof(int),
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GFP_NOFS);
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if (!c->gap_lebs)
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return -ENOMEM;
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p = c->gap_lebs;
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do {
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ubifs_assert(c, p < c->gap_lebs + c->lst.idx_lebs);
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written = layout_leb_in_gaps(c, p);
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if (written < 0) {
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err = written;
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if (err != -ENOSPC) {
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kfree(c->gap_lebs);
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c->gap_lebs = NULL;
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return err;
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}
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if (!dbg_is_chk_index(c)) {
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/*
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* Do not print scary warnings if the debugging
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* option which forces in-the-gaps is enabled.
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*/
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ubifs_warn(c, "out of space");
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ubifs_dump_budg(c, &c->bi);
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ubifs_dump_lprops(c);
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}
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/* Try to commit anyway */
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break;
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}
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p++;
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cnt -= written;
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leb_needed_cnt = get_leb_cnt(c, cnt);
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dbg_gc("%d znodes remaining, need %d LEBs, have %d", cnt,
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leb_needed_cnt, c->ileb_cnt);
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} while (leb_needed_cnt > c->ileb_cnt);
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*p = -1;
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return 0;
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}
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/**
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* layout_in_empty_space - layout index nodes in empty space.
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* @c: UBIFS file-system description object
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*
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* This function lays out new index nodes for dirty znodes using empty LEBs.
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*
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* This function returns %0 on success and a negative error code on failure.
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*/
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static int layout_in_empty_space(struct ubifs_info *c)
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{
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struct ubifs_znode *znode, *cnext, *zp;
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int lnum, offs, len, next_len, buf_len, buf_offs, used, avail;
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int wlen, blen, err;
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cnext = c->enext;
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if (!cnext)
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return 0;
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lnum = c->ihead_lnum;
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buf_offs = c->ihead_offs;
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buf_len = ubifs_idx_node_sz(c, c->fanout);
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buf_len = ALIGN(buf_len, c->min_io_size);
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used = 0;
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avail = buf_len;
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/* Ensure there is enough room for first write */
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next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
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if (buf_offs + next_len > c->leb_size)
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lnum = -1;
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while (1) {
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znode = cnext;
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len = ubifs_idx_node_sz(c, znode->child_cnt);
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/* Determine the index node position */
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if (lnum == -1) {
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if (c->ileb_nxt >= c->ileb_cnt) {
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ubifs_err(c, "out of space");
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return -ENOSPC;
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}
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lnum = c->ilebs[c->ileb_nxt++];
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buf_offs = 0;
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used = 0;
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avail = buf_len;
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}
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offs = buf_offs + used;
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znode->lnum = lnum;
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znode->offs = offs;
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znode->len = len;
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/* Update the parent */
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zp = znode->parent;
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if (zp) {
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struct ubifs_zbranch *zbr;
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int i;
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i = znode->iip;
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zbr = &zp->zbranch[i];
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zbr->lnum = lnum;
|
|
zbr->offs = offs;
|
|
zbr->len = len;
|
|
} else {
|
|
c->zroot.lnum = lnum;
|
|
c->zroot.offs = offs;
|
|
c->zroot.len = len;
|
|
}
|
|
c->calc_idx_sz += ALIGN(len, 8);
|
|
|
|
/*
|
|
* Once lprops is updated, we can decrease the dirty znode count
|
|
* but it is easier to just do it here.
|
|
*/
|
|
atomic_long_dec(&c->dirty_zn_cnt);
|
|
|
|
/*
|
|
* Calculate the next index node length to see if there is
|
|
* enough room for it
|
|
*/
|
|
cnext = znode->cnext;
|
|
if (cnext == c->cnext)
|
|
next_len = 0;
|
|
else
|
|
next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
|
|
|
|
/* Update buffer positions */
|
|
wlen = used + len;
|
|
used += ALIGN(len, 8);
|
|
avail -= ALIGN(len, 8);
|
|
|
|
if (next_len != 0 &&
|
|
buf_offs + used + next_len <= c->leb_size &&
|
|
avail > 0)
|
|
continue;
|
|
|
|
if (avail <= 0 && next_len &&
|
|
buf_offs + used + next_len <= c->leb_size)
|
|
blen = buf_len;
|
|
else
|
|
blen = ALIGN(wlen, c->min_io_size);
|
|
|
|
/* The buffer is full or there are no more znodes to do */
|
|
buf_offs += blen;
|
|
if (next_len) {
|
|
if (buf_offs + next_len > c->leb_size) {
|
|
err = ubifs_update_one_lp(c, lnum,
|
|
c->leb_size - buf_offs, blen - used,
|
|
0, 0);
|
|
if (err)
|
|
return err;
|
|
lnum = -1;
|
|
}
|
|
used -= blen;
|
|
if (used < 0)
|
|
used = 0;
|
|
avail = buf_len - used;
|
|
continue;
|
|
}
|
|
err = ubifs_update_one_lp(c, lnum, c->leb_size - buf_offs,
|
|
blen - used, 0, 0);
|
|
if (err)
|
|
return err;
|
|
break;
|
|
}
|
|
|
|
c->dbg->new_ihead_lnum = lnum;
|
|
c->dbg->new_ihead_offs = buf_offs;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* layout_commit - determine positions of index nodes to commit.
|
|
* @c: UBIFS file-system description object
|
|
* @no_space: indicates that insufficient empty LEBs were allocated
|
|
* @cnt: number of znodes to commit
|
|
*
|
|
* Calculate and update the positions of index nodes to commit. If there were
|
|
* an insufficient number of empty LEBs allocated, then index nodes are placed
|
|
* into the gaps created by obsolete index nodes in non-empty index LEBs. For
|
|
* this purpose, an obsolete index node is one that was not in the index as at
|
|
* the end of the last commit. To write "in-the-gaps" requires that those index
|
|
* LEBs are updated atomically in-place.
|
|
*/
|
|
static int layout_commit(struct ubifs_info *c, int no_space, int cnt)
|
|
{
|
|
int err;
|
|
|
|
if (no_space) {
|
|
err = layout_in_gaps(c, cnt);
|
|
if (err)
|
|
return err;
|
|
}
|
|
err = layout_in_empty_space(c);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* find_first_dirty - find first dirty znode.
|
|
* @znode: znode to begin searching from
|
|
*/
|
|
static struct ubifs_znode *find_first_dirty(struct ubifs_znode *znode)
|
|
{
|
|
int i, cont;
|
|
|
|
if (!znode)
|
|
return NULL;
|
|
|
|
while (1) {
|
|
if (znode->level == 0) {
|
|
if (ubifs_zn_dirty(znode))
|
|
return znode;
|
|
return NULL;
|
|
}
|
|
cont = 0;
|
|
for (i = 0; i < znode->child_cnt; i++) {
|
|
struct ubifs_zbranch *zbr = &znode->zbranch[i];
|
|
|
|
if (zbr->znode && ubifs_zn_dirty(zbr->znode)) {
|
|
znode = zbr->znode;
|
|
cont = 1;
|
|
break;
|
|
}
|
|
}
|
|
if (!cont) {
|
|
if (ubifs_zn_dirty(znode))
|
|
return znode;
|
|
return NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* find_next_dirty - find next dirty znode.
|
|
* @znode: znode to begin searching from
|
|
*/
|
|
static struct ubifs_znode *find_next_dirty(struct ubifs_znode *znode)
|
|
{
|
|
int n = znode->iip + 1;
|
|
|
|
znode = znode->parent;
|
|
if (!znode)
|
|
return NULL;
|
|
for (; n < znode->child_cnt; n++) {
|
|
struct ubifs_zbranch *zbr = &znode->zbranch[n];
|
|
|
|
if (zbr->znode && ubifs_zn_dirty(zbr->znode))
|
|
return find_first_dirty(zbr->znode);
|
|
}
|
|
return znode;
|
|
}
|
|
|
|
/**
|
|
* get_znodes_to_commit - create list of dirty znodes to commit.
|
|
* @c: UBIFS file-system description object
|
|
*
|
|
* This function returns the number of znodes to commit.
|
|
*/
|
|
static int get_znodes_to_commit(struct ubifs_info *c)
|
|
{
|
|
struct ubifs_znode *znode, *cnext;
|
|
int cnt = 0;
|
|
|
|
c->cnext = find_first_dirty(c->zroot.znode);
|
|
znode = c->enext = c->cnext;
|
|
if (!znode) {
|
|
dbg_cmt("no znodes to commit");
|
|
return 0;
|
|
}
|
|
cnt += 1;
|
|
while (1) {
|
|
ubifs_assert(c, !ubifs_zn_cow(znode));
|
|
__set_bit(COW_ZNODE, &znode->flags);
|
|
znode->alt = 0;
|
|
cnext = find_next_dirty(znode);
|
|
if (!cnext) {
|
|
znode->cnext = c->cnext;
|
|
break;
|
|
}
|
|
znode->cparent = znode->parent;
|
|
znode->ciip = znode->iip;
|
|
znode->cnext = cnext;
|
|
znode = cnext;
|
|
cnt += 1;
|
|
}
|
|
dbg_cmt("committing %d znodes", cnt);
|
|
ubifs_assert(c, cnt == atomic_long_read(&c->dirty_zn_cnt));
|
|
return cnt;
|
|
}
|
|
|
|
/**
|
|
* alloc_idx_lebs - allocate empty LEBs to be used to commit.
|
|
* @c: UBIFS file-system description object
|
|
* @cnt: number of znodes to commit
|
|
*
|
|
* This function returns %-ENOSPC if it cannot allocate a sufficient number of
|
|
* empty LEBs. %0 is returned on success, otherwise a negative error code
|
|
* is returned.
|
|
*/
|
|
static int alloc_idx_lebs(struct ubifs_info *c, int cnt)
|
|
{
|
|
int i, leb_cnt, lnum;
|
|
|
|
c->ileb_cnt = 0;
|
|
c->ileb_nxt = 0;
|
|
leb_cnt = get_leb_cnt(c, cnt);
|
|
dbg_cmt("need about %d empty LEBS for TNC commit", leb_cnt);
|
|
if (!leb_cnt)
|
|
return 0;
|
|
c->ilebs = kmalloc_array(leb_cnt, sizeof(int), GFP_NOFS);
|
|
if (!c->ilebs)
|
|
return -ENOMEM;
|
|
for (i = 0; i < leb_cnt; i++) {
|
|
lnum = ubifs_find_free_leb_for_idx(c);
|
|
if (lnum < 0)
|
|
return lnum;
|
|
c->ilebs[c->ileb_cnt++] = lnum;
|
|
dbg_cmt("LEB %d", lnum);
|
|
}
|
|
if (dbg_is_chk_index(c) && !(prandom_u32() & 7))
|
|
return -ENOSPC;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* free_unused_idx_lebs - free unused LEBs that were allocated for the commit.
|
|
* @c: UBIFS file-system description object
|
|
*
|
|
* It is possible that we allocate more empty LEBs for the commit than we need.
|
|
* This functions frees the surplus.
|
|
*
|
|
* This function returns %0 on success and a negative error code on failure.
|
|
*/
|
|
static int free_unused_idx_lebs(struct ubifs_info *c)
|
|
{
|
|
int i, err = 0, lnum, er;
|
|
|
|
for (i = c->ileb_nxt; i < c->ileb_cnt; i++) {
|
|
lnum = c->ilebs[i];
|
|
dbg_cmt("LEB %d", lnum);
|
|
er = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
|
|
LPROPS_INDEX | LPROPS_TAKEN, 0);
|
|
if (!err)
|
|
err = er;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* free_idx_lebs - free unused LEBs after commit end.
|
|
* @c: UBIFS file-system description object
|
|
*
|
|
* This function returns %0 on success and a negative error code on failure.
|
|
*/
|
|
static int free_idx_lebs(struct ubifs_info *c)
|
|
{
|
|
int err;
|
|
|
|
err = free_unused_idx_lebs(c);
|
|
kfree(c->ilebs);
|
|
c->ilebs = NULL;
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_start_commit - start TNC commit.
|
|
* @c: UBIFS file-system description object
|
|
* @zroot: new index root position is returned here
|
|
*
|
|
* This function prepares the list of indexing nodes to commit and lays out
|
|
* their positions on flash. If there is not enough free space it uses the
|
|
* in-gap commit method. Returns zero in case of success and a negative error
|
|
* code in case of failure.
|
|
*/
|
|
int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot)
|
|
{
|
|
int err = 0, cnt;
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
err = dbg_check_tnc(c, 1);
|
|
if (err)
|
|
goto out;
|
|
cnt = get_znodes_to_commit(c);
|
|
if (cnt != 0) {
|
|
int no_space = 0;
|
|
|
|
err = alloc_idx_lebs(c, cnt);
|
|
if (err == -ENOSPC)
|
|
no_space = 1;
|
|
else if (err)
|
|
goto out_free;
|
|
err = layout_commit(c, no_space, cnt);
|
|
if (err)
|
|
goto out_free;
|
|
ubifs_assert(c, atomic_long_read(&c->dirty_zn_cnt) == 0);
|
|
err = free_unused_idx_lebs(c);
|
|
if (err)
|
|
goto out;
|
|
}
|
|
destroy_old_idx(c);
|
|
memcpy(zroot, &c->zroot, sizeof(struct ubifs_zbranch));
|
|
|
|
err = ubifs_save_dirty_idx_lnums(c);
|
|
if (err)
|
|
goto out;
|
|
|
|
spin_lock(&c->space_lock);
|
|
/*
|
|
* Although we have not finished committing yet, update size of the
|
|
* committed index ('c->bi.old_idx_sz') and zero out the index growth
|
|
* budget. It is OK to do this now, because we've reserved all the
|
|
* space which is needed to commit the index, and it is save for the
|
|
* budgeting subsystem to assume the index is already committed,
|
|
* even though it is not.
|
|
*/
|
|
ubifs_assert(c, c->bi.min_idx_lebs == ubifs_calc_min_idx_lebs(c));
|
|
c->bi.old_idx_sz = c->calc_idx_sz;
|
|
c->bi.uncommitted_idx = 0;
|
|
c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
|
|
spin_unlock(&c->space_lock);
|
|
mutex_unlock(&c->tnc_mutex);
|
|
|
|
dbg_cmt("number of index LEBs %d", c->lst.idx_lebs);
|
|
dbg_cmt("size of index %llu", c->calc_idx_sz);
|
|
return err;
|
|
|
|
out_free:
|
|
free_idx_lebs(c);
|
|
out:
|
|
mutex_unlock(&c->tnc_mutex);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* write_index - write index nodes.
|
|
* @c: UBIFS file-system description object
|
|
*
|
|
* This function writes the index nodes whose positions were laid out in the
|
|
* layout_in_empty_space function.
|
|
*/
|
|
static int write_index(struct ubifs_info *c)
|
|
{
|
|
struct ubifs_idx_node *idx;
|
|
struct ubifs_znode *znode, *cnext;
|
|
int i, lnum, offs, len, next_len, buf_len, buf_offs, used;
|
|
int avail, wlen, err, lnum_pos = 0, blen, nxt_offs;
|
|
|
|
cnext = c->enext;
|
|
if (!cnext)
|
|
return 0;
|
|
|
|
/*
|
|
* Always write index nodes to the index head so that index nodes and
|
|
* other types of nodes are never mixed in the same erase block.
|
|
*/
|
|
lnum = c->ihead_lnum;
|
|
buf_offs = c->ihead_offs;
|
|
|
|
/* Allocate commit buffer */
|
|
buf_len = ALIGN(c->max_idx_node_sz, c->min_io_size);
|
|
used = 0;
|
|
avail = buf_len;
|
|
|
|
/* Ensure there is enough room for first write */
|
|
next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
|
|
if (buf_offs + next_len > c->leb_size) {
|
|
err = ubifs_update_one_lp(c, lnum, LPROPS_NC, 0, 0,
|
|
LPROPS_TAKEN);
|
|
if (err)
|
|
return err;
|
|
lnum = -1;
|
|
}
|
|
|
|
while (1) {
|
|
u8 hash[UBIFS_HASH_ARR_SZ];
|
|
|
|
cond_resched();
|
|
|
|
znode = cnext;
|
|
idx = c->cbuf + used;
|
|
|
|
/* Make index node */
|
|
idx->ch.node_type = UBIFS_IDX_NODE;
|
|
idx->child_cnt = cpu_to_le16(znode->child_cnt);
|
|
idx->level = cpu_to_le16(znode->level);
|
|
for (i = 0; i < znode->child_cnt; i++) {
|
|
struct ubifs_branch *br = ubifs_idx_branch(c, idx, i);
|
|
struct ubifs_zbranch *zbr = &znode->zbranch[i];
|
|
|
|
key_write_idx(c, &zbr->key, &br->key);
|
|
br->lnum = cpu_to_le32(zbr->lnum);
|
|
br->offs = cpu_to_le32(zbr->offs);
|
|
br->len = cpu_to_le32(zbr->len);
|
|
ubifs_copy_hash(c, zbr->hash, ubifs_branch_hash(c, br));
|
|
if (!zbr->lnum || !zbr->len) {
|
|
ubifs_err(c, "bad ref in znode");
|
|
ubifs_dump_znode(c, znode);
|
|
if (zbr->znode)
|
|
ubifs_dump_znode(c, zbr->znode);
|
|
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
len = ubifs_idx_node_sz(c, znode->child_cnt);
|
|
ubifs_prepare_node(c, idx, len, 0);
|
|
ubifs_node_calc_hash(c, idx, hash);
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
|
|
if (znode->cparent)
|
|
ubifs_copy_hash(c, hash,
|
|
znode->cparent->zbranch[znode->ciip].hash);
|
|
|
|
if (znode->parent) {
|
|
if (!ubifs_zn_obsolete(znode))
|
|
ubifs_copy_hash(c, hash,
|
|
znode->parent->zbranch[znode->iip].hash);
|
|
} else {
|
|
ubifs_copy_hash(c, hash, c->zroot.hash);
|
|
}
|
|
|
|
mutex_unlock(&c->tnc_mutex);
|
|
|
|
/* Determine the index node position */
|
|
if (lnum == -1) {
|
|
lnum = c->ilebs[lnum_pos++];
|
|
buf_offs = 0;
|
|
used = 0;
|
|
avail = buf_len;
|
|
}
|
|
offs = buf_offs + used;
|
|
|
|
if (lnum != znode->lnum || offs != znode->offs ||
|
|
len != znode->len) {
|
|
ubifs_err(c, "inconsistent znode posn");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Grab some stuff from znode while we still can */
|
|
cnext = znode->cnext;
|
|
|
|
ubifs_assert(c, ubifs_zn_dirty(znode));
|
|
ubifs_assert(c, ubifs_zn_cow(znode));
|
|
|
|
/*
|
|
* It is important that other threads should see %DIRTY_ZNODE
|
|
* flag cleared before %COW_ZNODE. Specifically, it matters in
|
|
* the 'dirty_cow_znode()' function. This is the reason for the
|
|
* first barrier. Also, we want the bit changes to be seen to
|
|
* other threads ASAP, to avoid unnecesarry copying, which is
|
|
* the reason for the second barrier.
|
|
*/
|
|
clear_bit(DIRTY_ZNODE, &znode->flags);
|
|
smp_mb__before_atomic();
|
|
clear_bit(COW_ZNODE, &znode->flags);
|
|
smp_mb__after_atomic();
|
|
|
|
/*
|
|
* We have marked the znode as clean but have not updated the
|
|
* @c->clean_zn_cnt counter. If this znode becomes dirty again
|
|
* before 'free_obsolete_znodes()' is called, then
|
|
* @c->clean_zn_cnt will be decremented before it gets
|
|
* incremented (resulting in 2 decrements for the same znode).
|
|
* This means that @c->clean_zn_cnt may become negative for a
|
|
* while.
|
|
*
|
|
* Q: why we cannot increment @c->clean_zn_cnt?
|
|
* A: because we do not have the @c->tnc_mutex locked, and the
|
|
* following code would be racy and buggy:
|
|
*
|
|
* if (!ubifs_zn_obsolete(znode)) {
|
|
* atomic_long_inc(&c->clean_zn_cnt);
|
|
* atomic_long_inc(&ubifs_clean_zn_cnt);
|
|
* }
|
|
*
|
|
* Thus, we just delay the @c->clean_zn_cnt update until we
|
|
* have the mutex locked.
|
|
*/
|
|
|
|
/* Do not access znode from this point on */
|
|
|
|
/* Update buffer positions */
|
|
wlen = used + len;
|
|
used += ALIGN(len, 8);
|
|
avail -= ALIGN(len, 8);
|
|
|
|
/*
|
|
* Calculate the next index node length to see if there is
|
|
* enough room for it
|
|
*/
|
|
if (cnext == c->cnext)
|
|
next_len = 0;
|
|
else
|
|
next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
|
|
|
|
nxt_offs = buf_offs + used + next_len;
|
|
if (next_len && nxt_offs <= c->leb_size) {
|
|
if (avail > 0)
|
|
continue;
|
|
else
|
|
blen = buf_len;
|
|
} else {
|
|
wlen = ALIGN(wlen, 8);
|
|
blen = ALIGN(wlen, c->min_io_size);
|
|
ubifs_pad(c, c->cbuf + wlen, blen - wlen);
|
|
}
|
|
|
|
/* The buffer is full or there are no more znodes to do */
|
|
err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs, blen);
|
|
if (err)
|
|
return err;
|
|
buf_offs += blen;
|
|
if (next_len) {
|
|
if (nxt_offs > c->leb_size) {
|
|
err = ubifs_update_one_lp(c, lnum, LPROPS_NC, 0,
|
|
0, LPROPS_TAKEN);
|
|
if (err)
|
|
return err;
|
|
lnum = -1;
|
|
}
|
|
used -= blen;
|
|
if (used < 0)
|
|
used = 0;
|
|
avail = buf_len - used;
|
|
memmove(c->cbuf, c->cbuf + blen, used);
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (lnum != c->dbg->new_ihead_lnum ||
|
|
buf_offs != c->dbg->new_ihead_offs) {
|
|
ubifs_err(c, "inconsistent ihead");
|
|
return -EINVAL;
|
|
}
|
|
|
|
c->ihead_lnum = lnum;
|
|
c->ihead_offs = buf_offs;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* free_obsolete_znodes - free obsolete znodes.
|
|
* @c: UBIFS file-system description object
|
|
*
|
|
* At the end of commit end, obsolete znodes are freed.
|
|
*/
|
|
static void free_obsolete_znodes(struct ubifs_info *c)
|
|
{
|
|
struct ubifs_znode *znode, *cnext;
|
|
|
|
cnext = c->cnext;
|
|
do {
|
|
znode = cnext;
|
|
cnext = znode->cnext;
|
|
if (ubifs_zn_obsolete(znode))
|
|
kfree(znode);
|
|
else {
|
|
znode->cnext = NULL;
|
|
atomic_long_inc(&c->clean_zn_cnt);
|
|
atomic_long_inc(&ubifs_clean_zn_cnt);
|
|
}
|
|
} while (cnext != c->cnext);
|
|
}
|
|
|
|
/**
|
|
* return_gap_lebs - return LEBs used by the in-gap commit method.
|
|
* @c: UBIFS file-system description object
|
|
*
|
|
* This function clears the "taken" flag for the LEBs which were used by the
|
|
* "commit in-the-gaps" method.
|
|
*/
|
|
static int return_gap_lebs(struct ubifs_info *c)
|
|
{
|
|
int *p, err;
|
|
|
|
if (!c->gap_lebs)
|
|
return 0;
|
|
|
|
dbg_cmt("");
|
|
for (p = c->gap_lebs; *p != -1; p++) {
|
|
err = ubifs_change_one_lp(c, *p, LPROPS_NC, LPROPS_NC, 0,
|
|
LPROPS_TAKEN, 0);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
kfree(c->gap_lebs);
|
|
c->gap_lebs = NULL;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_end_commit - update the TNC for commit end.
|
|
* @c: UBIFS file-system description object
|
|
*
|
|
* Write the dirty znodes.
|
|
*/
|
|
int ubifs_tnc_end_commit(struct ubifs_info *c)
|
|
{
|
|
int err;
|
|
|
|
if (!c->cnext)
|
|
return 0;
|
|
|
|
err = return_gap_lebs(c);
|
|
if (err)
|
|
return err;
|
|
|
|
err = write_index(c);
|
|
if (err)
|
|
return err;
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
|
|
dbg_cmt("TNC height is %d", c->zroot.znode->level + 1);
|
|
|
|
free_obsolete_znodes(c);
|
|
|
|
c->cnext = NULL;
|
|
kfree(c->ilebs);
|
|
c->ilebs = NULL;
|
|
|
|
mutex_unlock(&c->tnc_mutex);
|
|
|
|
return 0;
|
|
}
|