forked from Minki/linux
3271 lines
85 KiB
C
3271 lines
85 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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/*
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* This file implements TNC (Tree Node Cache) which caches indexing nodes of
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* the UBIFS B-tree.
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*
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* At the moment the locking rules of the TNC tree are quite simple and
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* straightforward. We just have a mutex and lock it when we traverse the
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* tree. If a znode is not in memory, we read it from flash while still having
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* the mutex locked.
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*/
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#include <linux/crc32.h>
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#include "ubifs.h"
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/*
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* Returned codes of 'matches_name()' and 'fallible_matches_name()' functions.
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* @NAME_LESS: name corresponding to the first argument is less than second
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* @NAME_MATCHES: names match
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* @NAME_GREATER: name corresponding to the second argument is greater than
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* first
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* @NOT_ON_MEDIA: node referred by zbranch does not exist on the media
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*
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* These constants were introduce to improve readability.
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*/
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enum {
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NAME_LESS = 0,
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NAME_MATCHES = 1,
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NAME_GREATER = 2,
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NOT_ON_MEDIA = 3,
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};
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/**
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* insert_old_idx - record 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 %0 on success, and a negative error code on failure.
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*
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* For recovery, there must always be a complete intact version of the index on
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* flash at all times. That is called the "old index". It is the index as at the
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* time of the last successful commit. Many of the index nodes in the old index
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* may be dirty, but they must not be erased until the next successful commit
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* (at which point that index becomes the old index).
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*
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* That means that the garbage collection and the in-the-gaps method of
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* committing must be able to determine if an index node is in the old index.
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* Most of the old index nodes can be found by looking up the TNC using the
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* 'lookup_znode()' function. However, some of the old index nodes may have
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* been deleted from the current index or may have been changed so much that
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* they cannot be easily found. In those cases, an entry is added to an RB-tree.
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* That is what this function does. The RB-tree is ordered by LEB number and
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* offset because they uniquely identify the old index node.
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*/
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static int insert_old_idx(struct ubifs_info *c, int lnum, int offs)
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{
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struct ubifs_old_idx *old_idx, *o;
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struct rb_node **p, *parent = NULL;
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old_idx = kmalloc(sizeof(struct ubifs_old_idx), GFP_NOFS);
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if (unlikely(!old_idx))
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return -ENOMEM;
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old_idx->lnum = lnum;
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old_idx->offs = offs;
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p = &c->old_idx.rb_node;
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while (*p) {
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parent = *p;
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o = rb_entry(parent, 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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ubifs_err("old idx added twice!");
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kfree(old_idx);
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return 0;
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}
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}
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rb_link_node(&old_idx->rb, parent, p);
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rb_insert_color(&old_idx->rb, &c->old_idx);
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return 0;
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}
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/**
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* insert_old_idx_znode - record a znode obsoleted since last commit start.
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* @c: UBIFS file-system description object
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* @znode: znode of obsoleted index node
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*
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* Returns %0 on success, and a negative error code on failure.
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*/
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int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode)
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{
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if (znode->parent) {
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struct ubifs_zbranch *zbr;
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zbr = &znode->parent->zbranch[znode->iip];
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if (zbr->len)
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return insert_old_idx(c, zbr->lnum, zbr->offs);
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} else
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if (c->zroot.len)
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return insert_old_idx(c, c->zroot.lnum,
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c->zroot.offs);
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return 0;
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}
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/**
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* ins_clr_old_idx_znode - record a znode obsoleted since last commit start.
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* @c: UBIFS file-system description object
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* @znode: znode of obsoleted index node
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*
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* Returns %0 on success, and a negative error code on failure.
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*/
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static int ins_clr_old_idx_znode(struct ubifs_info *c,
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struct ubifs_znode *znode)
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{
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int err;
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if (znode->parent) {
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struct ubifs_zbranch *zbr;
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zbr = &znode->parent->zbranch[znode->iip];
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if (zbr->len) {
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err = insert_old_idx(c, zbr->lnum, zbr->offs);
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if (err)
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return err;
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zbr->lnum = 0;
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zbr->offs = 0;
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zbr->len = 0;
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}
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} else
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if (c->zroot.len) {
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err = insert_old_idx(c, c->zroot.lnum, c->zroot.offs);
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if (err)
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return err;
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c->zroot.lnum = 0;
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c->zroot.offs = 0;
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c->zroot.len = 0;
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}
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return 0;
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}
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/**
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* destroy_old_idx - destroy the old_idx RB-tree.
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* @c: UBIFS file-system description object
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*
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* During start commit, the old_idx RB-tree is used to avoid overwriting index
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* nodes that were in the index last commit but have since been deleted. This
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* is necessary for recovery i.e. the old index must be kept intact until the
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* new index is successfully written. The old-idx RB-tree is used for the
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* in-the-gaps method of writing index nodes and is destroyed every commit.
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*/
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void destroy_old_idx(struct ubifs_info *c)
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{
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struct rb_node *this = c->old_idx.rb_node;
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struct ubifs_old_idx *old_idx;
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while (this) {
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if (this->rb_left) {
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this = this->rb_left;
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continue;
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} else if (this->rb_right) {
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this = this->rb_right;
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continue;
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}
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old_idx = rb_entry(this, struct ubifs_old_idx, rb);
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this = rb_parent(this);
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if (this) {
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if (this->rb_left == &old_idx->rb)
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this->rb_left = NULL;
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else
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this->rb_right = NULL;
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}
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kfree(old_idx);
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}
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c->old_idx = RB_ROOT;
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}
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/**
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* copy_znode - copy a dirty znode.
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* @c: UBIFS file-system description object
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* @znode: znode to copy
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*
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* A dirty znode being committed may not be changed, so it is copied.
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*/
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static struct ubifs_znode *copy_znode(struct ubifs_info *c,
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struct ubifs_znode *znode)
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{
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struct ubifs_znode *zn;
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zn = kmalloc(c->max_znode_sz, GFP_NOFS);
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if (unlikely(!zn))
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return ERR_PTR(-ENOMEM);
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memcpy(zn, znode, c->max_znode_sz);
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zn->cnext = NULL;
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__set_bit(DIRTY_ZNODE, &zn->flags);
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__clear_bit(COW_ZNODE, &zn->flags);
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ubifs_assert(!test_bit(OBSOLETE_ZNODE, &znode->flags));
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__set_bit(OBSOLETE_ZNODE, &znode->flags);
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if (znode->level != 0) {
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int i;
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const int n = zn->child_cnt;
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/* The children now have new parent */
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for (i = 0; i < n; i++) {
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struct ubifs_zbranch *zbr = &zn->zbranch[i];
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if (zbr->znode)
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zbr->znode->parent = zn;
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}
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}
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atomic_long_inc(&c->dirty_zn_cnt);
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return zn;
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}
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/**
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* add_idx_dirt - add dirt due to a dirty znode.
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* @c: UBIFS file-system description object
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* @lnum: LEB number of index node
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* @dirt: size of index node
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*
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* This function updates lprops dirty space and the new size of the index.
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*/
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static int add_idx_dirt(struct ubifs_info *c, int lnum, int dirt)
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{
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c->calc_idx_sz -= ALIGN(dirt, 8);
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return ubifs_add_dirt(c, lnum, dirt);
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}
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/**
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* dirty_cow_znode - ensure a znode is not being committed.
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* @c: UBIFS file-system description object
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* @zbr: branch of znode to check
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*
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* Returns dirtied znode on success or negative error code on failure.
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*/
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static struct ubifs_znode *dirty_cow_znode(struct ubifs_info *c,
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struct ubifs_zbranch *zbr)
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{
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struct ubifs_znode *znode = zbr->znode;
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struct ubifs_znode *zn;
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int err;
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if (!test_bit(COW_ZNODE, &znode->flags)) {
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/* znode is not being committed */
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if (!test_and_set_bit(DIRTY_ZNODE, &znode->flags)) {
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atomic_long_inc(&c->dirty_zn_cnt);
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atomic_long_dec(&c->clean_zn_cnt);
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atomic_long_dec(&ubifs_clean_zn_cnt);
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err = add_idx_dirt(c, zbr->lnum, zbr->len);
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if (unlikely(err))
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return ERR_PTR(err);
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}
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return znode;
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}
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zn = copy_znode(c, znode);
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if (IS_ERR(zn))
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return zn;
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if (zbr->len) {
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err = insert_old_idx(c, zbr->lnum, zbr->offs);
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if (unlikely(err))
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return ERR_PTR(err);
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err = add_idx_dirt(c, zbr->lnum, zbr->len);
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} else
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err = 0;
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zbr->znode = zn;
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zbr->lnum = 0;
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zbr->offs = 0;
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zbr->len = 0;
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if (unlikely(err))
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return ERR_PTR(err);
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return zn;
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}
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/**
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* lnc_add - add a leaf node to the leaf node cache.
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* @c: UBIFS file-system description object
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* @zbr: zbranch of leaf node
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* @node: leaf node
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*
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* Leaf nodes are non-index nodes directory entry nodes or data nodes. The
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* purpose of the leaf node cache is to save re-reading the same leaf node over
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* and over again. Most things are cached by VFS, however the file system must
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* cache directory entries for readdir and for resolving hash collisions. The
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* present implementation of the leaf node cache is extremely simple, and
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* allows for error returns that are not used but that may be needed if a more
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* complex implementation is created.
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*
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* Note, this function does not add the @node object to LNC directly, but
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* allocates a copy of the object and adds the copy to LNC. The reason for this
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* is that @node has been allocated outside of the TNC subsystem and will be
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* used with @c->tnc_mutex unlock upon return from the TNC subsystem. But LNC
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* may be changed at any time, e.g. freed by the shrinker.
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*/
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static int lnc_add(struct ubifs_info *c, struct ubifs_zbranch *zbr,
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const void *node)
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{
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int err;
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void *lnc_node;
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const struct ubifs_dent_node *dent = node;
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ubifs_assert(!zbr->leaf);
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ubifs_assert(zbr->len != 0);
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ubifs_assert(is_hash_key(c, &zbr->key));
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err = ubifs_validate_entry(c, dent);
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if (err) {
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dbg_dump_stack();
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dbg_dump_node(c, dent);
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return err;
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}
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lnc_node = kmalloc(zbr->len, GFP_NOFS);
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if (!lnc_node)
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/* We don't have to have the cache, so no error */
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return 0;
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memcpy(lnc_node, node, zbr->len);
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zbr->leaf = lnc_node;
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return 0;
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}
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/**
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* lnc_add_directly - add a leaf node to the leaf-node-cache.
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* @c: UBIFS file-system description object
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* @zbr: zbranch of leaf node
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* @node: leaf node
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*
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* This function is similar to 'lnc_add()', but it does not create a copy of
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* @node but inserts @node to TNC directly.
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*/
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static int lnc_add_directly(struct ubifs_info *c, struct ubifs_zbranch *zbr,
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void *node)
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{
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int err;
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ubifs_assert(!zbr->leaf);
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ubifs_assert(zbr->len != 0);
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err = ubifs_validate_entry(c, node);
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if (err) {
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dbg_dump_stack();
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dbg_dump_node(c, node);
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return err;
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}
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zbr->leaf = node;
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return 0;
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}
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/**
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* lnc_free - remove a leaf node from the leaf node cache.
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* @zbr: zbranch of leaf node
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* @node: leaf node
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*/
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static void lnc_free(struct ubifs_zbranch *zbr)
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{
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if (!zbr->leaf)
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return;
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kfree(zbr->leaf);
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zbr->leaf = NULL;
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}
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/**
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* tnc_read_node_nm - read a "hashed" leaf node.
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* @c: UBIFS file-system description object
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* @zbr: key and position of the node
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* @node: node is returned here
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*
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* This function reads a "hashed" node defined by @zbr from the leaf node cache
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* (in it is there) or from the hash media, in which case the node is also
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* added to LNC. Returns zero in case of success or a negative negative error
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* code in case of failure.
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*/
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static int tnc_read_node_nm(struct ubifs_info *c, struct ubifs_zbranch *zbr,
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void *node)
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{
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int err;
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ubifs_assert(is_hash_key(c, &zbr->key));
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if (zbr->leaf) {
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/* Read from the leaf node cache */
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ubifs_assert(zbr->len != 0);
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memcpy(node, zbr->leaf, zbr->len);
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return 0;
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}
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err = ubifs_tnc_read_node(c, zbr, node);
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if (err)
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return err;
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/* Add the node to the leaf node cache */
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err = lnc_add(c, zbr, node);
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return err;
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}
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/**
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* try_read_node - read a node if it is a node.
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* @c: UBIFS file-system description object
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* @buf: buffer to read to
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* @type: node type
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* @len: node length (not aligned)
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* @lnum: LEB number of node to read
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* @offs: offset of node to read
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*
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* This function tries to read a node of known type and length, checks it and
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* stores it in @buf. This function returns %1 if a node is present and %0 if
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* a node is not present. A negative error code is returned for I/O errors.
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* This function performs that same function as ubifs_read_node except that
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* it does not require that there is actually a node present and instead
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* the return code indicates if a node was read.
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*
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* Note, this function does not check CRC of data nodes if @c->no_chk_data_crc
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* is true (it is controlled by corresponding mount option). However, if
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* @c->always_chk_crc is true, @c->no_chk_data_crc is ignored and CRC is always
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* checked.
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*/
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static int try_read_node(const struct ubifs_info *c, void *buf, int type,
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int len, int lnum, int offs)
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{
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int err, node_len;
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struct ubifs_ch *ch = buf;
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uint32_t crc, node_crc;
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dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len);
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err = ubi_read(c->ubi, lnum, buf, offs, len);
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if (err) {
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ubifs_err("cannot read node type %d from LEB %d:%d, error %d",
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type, lnum, offs, err);
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return err;
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}
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if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC)
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return 0;
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if (ch->node_type != type)
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return 0;
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node_len = le32_to_cpu(ch->len);
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if (node_len != len)
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return 0;
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if (type == UBIFS_DATA_NODE && !c->always_chk_crc && c->no_chk_data_crc)
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return 1;
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crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8);
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node_crc = le32_to_cpu(ch->crc);
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if (crc != node_crc)
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return 0;
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return 1;
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}
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|
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/**
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|
* fallible_read_node - try to read a leaf node.
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|
* @c: UBIFS file-system description object
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|
* @key: key of node to read
|
|
* @zbr: position of node
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* @node: node returned
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*
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* This function tries to read a node and returns %1 if the node is read, %0
|
|
* if the node is not present, and a negative error code in the case of error.
|
|
*/
|
|
static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key,
|
|
struct ubifs_zbranch *zbr, void *node)
|
|
{
|
|
int ret;
|
|
|
|
dbg_tnc("LEB %d:%d, key %s", zbr->lnum, zbr->offs, DBGKEY(key));
|
|
|
|
ret = try_read_node(c, node, key_type(c, key), zbr->len, zbr->lnum,
|
|
zbr->offs);
|
|
if (ret == 1) {
|
|
union ubifs_key node_key;
|
|
struct ubifs_dent_node *dent = node;
|
|
|
|
/* All nodes have key in the same place */
|
|
key_read(c, &dent->key, &node_key);
|
|
if (keys_cmp(c, key, &node_key) != 0)
|
|
ret = 0;
|
|
}
|
|
if (ret == 0 && c->replaying)
|
|
dbg_mnt("dangling branch LEB %d:%d len %d, key %s",
|
|
zbr->lnum, zbr->offs, zbr->len, DBGKEY(key));
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* matches_name - determine if a direntry or xattr entry matches a given name.
|
|
* @c: UBIFS file-system description object
|
|
* @zbr: zbranch of dent
|
|
* @nm: name to match
|
|
*
|
|
* This function checks if xentry/direntry referred by zbranch @zbr matches name
|
|
* @nm. Returns %NAME_MATCHES if it does, %NAME_LESS if the name referred by
|
|
* @zbr is less than @nm, and %NAME_GREATER if it is greater than @nm. In case
|
|
* of failure, a negative error code is returned.
|
|
*/
|
|
static int matches_name(struct ubifs_info *c, struct ubifs_zbranch *zbr,
|
|
const struct qstr *nm)
|
|
{
|
|
struct ubifs_dent_node *dent;
|
|
int nlen, err;
|
|
|
|
/* If possible, match against the dent in the leaf node cache */
|
|
if (!zbr->leaf) {
|
|
dent = kmalloc(zbr->len, GFP_NOFS);
|
|
if (!dent)
|
|
return -ENOMEM;
|
|
|
|
err = ubifs_tnc_read_node(c, zbr, dent);
|
|
if (err)
|
|
goto out_free;
|
|
|
|
/* Add the node to the leaf node cache */
|
|
err = lnc_add_directly(c, zbr, dent);
|
|
if (err)
|
|
goto out_free;
|
|
} else
|
|
dent = zbr->leaf;
|
|
|
|
nlen = le16_to_cpu(dent->nlen);
|
|
err = memcmp(dent->name, nm->name, min_t(int, nlen, nm->len));
|
|
if (err == 0) {
|
|
if (nlen == nm->len)
|
|
return NAME_MATCHES;
|
|
else if (nlen < nm->len)
|
|
return NAME_LESS;
|
|
else
|
|
return NAME_GREATER;
|
|
} else if (err < 0)
|
|
return NAME_LESS;
|
|
else
|
|
return NAME_GREATER;
|
|
|
|
out_free:
|
|
kfree(dent);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* get_znode - get a TNC znode that may not be loaded yet.
|
|
* @c: UBIFS file-system description object
|
|
* @znode: parent znode
|
|
* @n: znode branch slot number
|
|
*
|
|
* This function returns the znode or a negative error code.
|
|
*/
|
|
static struct ubifs_znode *get_znode(struct ubifs_info *c,
|
|
struct ubifs_znode *znode, int n)
|
|
{
|
|
struct ubifs_zbranch *zbr;
|
|
|
|
zbr = &znode->zbranch[n];
|
|
if (zbr->znode)
|
|
znode = zbr->znode;
|
|
else
|
|
znode = ubifs_load_znode(c, zbr, znode, n);
|
|
return znode;
|
|
}
|
|
|
|
/**
|
|
* tnc_next - find next TNC entry.
|
|
* @c: UBIFS file-system description object
|
|
* @zn: znode is passed and returned here
|
|
* @n: znode branch slot number is passed and returned here
|
|
*
|
|
* This function returns %0 if the next TNC entry is found, %-ENOENT if there is
|
|
* no next entry, or a negative error code otherwise.
|
|
*/
|
|
static int tnc_next(struct ubifs_info *c, struct ubifs_znode **zn, int *n)
|
|
{
|
|
struct ubifs_znode *znode = *zn;
|
|
int nn = *n;
|
|
|
|
nn += 1;
|
|
if (nn < znode->child_cnt) {
|
|
*n = nn;
|
|
return 0;
|
|
}
|
|
while (1) {
|
|
struct ubifs_znode *zp;
|
|
|
|
zp = znode->parent;
|
|
if (!zp)
|
|
return -ENOENT;
|
|
nn = znode->iip + 1;
|
|
znode = zp;
|
|
if (nn < znode->child_cnt) {
|
|
znode = get_znode(c, znode, nn);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
while (znode->level != 0) {
|
|
znode = get_znode(c, znode, 0);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
}
|
|
nn = 0;
|
|
break;
|
|
}
|
|
}
|
|
*zn = znode;
|
|
*n = nn;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tnc_prev - find previous TNC entry.
|
|
* @c: UBIFS file-system description object
|
|
* @zn: znode is returned here
|
|
* @n: znode branch slot number is passed and returned here
|
|
*
|
|
* This function returns %0 if the previous TNC entry is found, %-ENOENT if
|
|
* there is no next entry, or a negative error code otherwise.
|
|
*/
|
|
static int tnc_prev(struct ubifs_info *c, struct ubifs_znode **zn, int *n)
|
|
{
|
|
struct ubifs_znode *znode = *zn;
|
|
int nn = *n;
|
|
|
|
if (nn > 0) {
|
|
*n = nn - 1;
|
|
return 0;
|
|
}
|
|
while (1) {
|
|
struct ubifs_znode *zp;
|
|
|
|
zp = znode->parent;
|
|
if (!zp)
|
|
return -ENOENT;
|
|
nn = znode->iip - 1;
|
|
znode = zp;
|
|
if (nn >= 0) {
|
|
znode = get_znode(c, znode, nn);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
while (znode->level != 0) {
|
|
nn = znode->child_cnt - 1;
|
|
znode = get_znode(c, znode, nn);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
}
|
|
nn = znode->child_cnt - 1;
|
|
break;
|
|
}
|
|
}
|
|
*zn = znode;
|
|
*n = nn;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* resolve_collision - resolve a collision.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key of a directory or extended attribute entry
|
|
* @zn: znode is returned here
|
|
* @n: zbranch number is passed and returned here
|
|
* @nm: name of the entry
|
|
*
|
|
* This function is called for "hashed" keys to make sure that the found key
|
|
* really corresponds to the looked up node (directory or extended attribute
|
|
* entry). It returns %1 and sets @zn and @n if the collision is resolved.
|
|
* %0 is returned if @nm is not found and @zn and @n are set to the previous
|
|
* entry, i.e. to the entry after which @nm could follow if it were in TNC.
|
|
* This means that @n may be set to %-1 if the leftmost key in @zn is the
|
|
* previous one. A negative error code is returned on failures.
|
|
*/
|
|
static int resolve_collision(struct ubifs_info *c, const union ubifs_key *key,
|
|
struct ubifs_znode **zn, int *n,
|
|
const struct qstr *nm)
|
|
{
|
|
int err;
|
|
|
|
err = matches_name(c, &(*zn)->zbranch[*n], nm);
|
|
if (unlikely(err < 0))
|
|
return err;
|
|
if (err == NAME_MATCHES)
|
|
return 1;
|
|
|
|
if (err == NAME_GREATER) {
|
|
/* Look left */
|
|
while (1) {
|
|
err = tnc_prev(c, zn, n);
|
|
if (err == -ENOENT) {
|
|
ubifs_assert(*n == 0);
|
|
*n = -1;
|
|
return 0;
|
|
}
|
|
if (err < 0)
|
|
return err;
|
|
if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) {
|
|
/*
|
|
* We have found the branch after which we would
|
|
* like to insert, but inserting in this znode
|
|
* may still be wrong. Consider the following 3
|
|
* znodes, in the case where we are resolving a
|
|
* collision with Key2.
|
|
*
|
|
* znode zp
|
|
* ----------------------
|
|
* level 1 | Key0 | Key1 |
|
|
* -----------------------
|
|
* | |
|
|
* znode za | | znode zb
|
|
* ------------ ------------
|
|
* level 0 | Key0 | | Key2 |
|
|
* ------------ ------------
|
|
*
|
|
* The lookup finds Key2 in znode zb. Lets say
|
|
* there is no match and the name is greater so
|
|
* we look left. When we find Key0, we end up
|
|
* here. If we return now, we will insert into
|
|
* znode za at slot n = 1. But that is invalid
|
|
* according to the parent's keys. Key2 must
|
|
* be inserted into znode zb.
|
|
*
|
|
* Note, this problem is not relevant for the
|
|
* case when we go right, because
|
|
* 'tnc_insert()' would correct the parent key.
|
|
*/
|
|
if (*n == (*zn)->child_cnt - 1) {
|
|
err = tnc_next(c, zn, n);
|
|
if (err) {
|
|
/* Should be impossible */
|
|
ubifs_assert(0);
|
|
if (err == -ENOENT)
|
|
err = -EINVAL;
|
|
return err;
|
|
}
|
|
ubifs_assert(*n == 0);
|
|
*n = -1;
|
|
}
|
|
return 0;
|
|
}
|
|
err = matches_name(c, &(*zn)->zbranch[*n], nm);
|
|
if (err < 0)
|
|
return err;
|
|
if (err == NAME_LESS)
|
|
return 0;
|
|
if (err == NAME_MATCHES)
|
|
return 1;
|
|
ubifs_assert(err == NAME_GREATER);
|
|
}
|
|
} else {
|
|
int nn = *n;
|
|
struct ubifs_znode *znode = *zn;
|
|
|
|
/* Look right */
|
|
while (1) {
|
|
err = tnc_next(c, &znode, &nn);
|
|
if (err == -ENOENT)
|
|
return 0;
|
|
if (err < 0)
|
|
return err;
|
|
if (keys_cmp(c, &znode->zbranch[nn].key, key))
|
|
return 0;
|
|
err = matches_name(c, &znode->zbranch[nn], nm);
|
|
if (err < 0)
|
|
return err;
|
|
if (err == NAME_GREATER)
|
|
return 0;
|
|
*zn = znode;
|
|
*n = nn;
|
|
if (err == NAME_MATCHES)
|
|
return 1;
|
|
ubifs_assert(err == NAME_LESS);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* fallible_matches_name - determine if a dent matches a given name.
|
|
* @c: UBIFS file-system description object
|
|
* @zbr: zbranch of dent
|
|
* @nm: name to match
|
|
*
|
|
* This is a "fallible" version of 'matches_name()' function which does not
|
|
* panic if the direntry/xentry referred by @zbr does not exist on the media.
|
|
*
|
|
* This function checks if xentry/direntry referred by zbranch @zbr matches name
|
|
* @nm. Returns %NAME_MATCHES it does, %NAME_LESS if the name referred by @zbr
|
|
* is less than @nm, %NAME_GREATER if it is greater than @nm, and @NOT_ON_MEDIA
|
|
* if xentry/direntry referred by @zbr does not exist on the media. A negative
|
|
* error code is returned in case of failure.
|
|
*/
|
|
static int fallible_matches_name(struct ubifs_info *c,
|
|
struct ubifs_zbranch *zbr,
|
|
const struct qstr *nm)
|
|
{
|
|
struct ubifs_dent_node *dent;
|
|
int nlen, err;
|
|
|
|
/* If possible, match against the dent in the leaf node cache */
|
|
if (!zbr->leaf) {
|
|
dent = kmalloc(zbr->len, GFP_NOFS);
|
|
if (!dent)
|
|
return -ENOMEM;
|
|
|
|
err = fallible_read_node(c, &zbr->key, zbr, dent);
|
|
if (err < 0)
|
|
goto out_free;
|
|
if (err == 0) {
|
|
/* The node was not present */
|
|
err = NOT_ON_MEDIA;
|
|
goto out_free;
|
|
}
|
|
ubifs_assert(err == 1);
|
|
|
|
err = lnc_add_directly(c, zbr, dent);
|
|
if (err)
|
|
goto out_free;
|
|
} else
|
|
dent = zbr->leaf;
|
|
|
|
nlen = le16_to_cpu(dent->nlen);
|
|
err = memcmp(dent->name, nm->name, min_t(int, nlen, nm->len));
|
|
if (err == 0) {
|
|
if (nlen == nm->len)
|
|
return NAME_MATCHES;
|
|
else if (nlen < nm->len)
|
|
return NAME_LESS;
|
|
else
|
|
return NAME_GREATER;
|
|
} else if (err < 0)
|
|
return NAME_LESS;
|
|
else
|
|
return NAME_GREATER;
|
|
|
|
out_free:
|
|
kfree(dent);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* fallible_resolve_collision - resolve a collision even if nodes are missing.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key
|
|
* @zn: znode is returned here
|
|
* @n: branch number is passed and returned here
|
|
* @nm: name of directory entry
|
|
* @adding: indicates caller is adding a key to the TNC
|
|
*
|
|
* This is a "fallible" version of the 'resolve_collision()' function which
|
|
* does not panic if one of the nodes referred to by TNC does not exist on the
|
|
* media. This may happen when replaying the journal if a deleted node was
|
|
* Garbage-collected and the commit was not done. A branch that refers to a node
|
|
* that is not present is called a dangling branch. The following are the return
|
|
* codes for this function:
|
|
* o if @nm was found, %1 is returned and @zn and @n are set to the found
|
|
* branch;
|
|
* o if we are @adding and @nm was not found, %0 is returned;
|
|
* o if we are not @adding and @nm was not found, but a dangling branch was
|
|
* found, then %1 is returned and @zn and @n are set to the dangling branch;
|
|
* o a negative error code is returned in case of failure.
|
|
*/
|
|
static int fallible_resolve_collision(struct ubifs_info *c,
|
|
const union ubifs_key *key,
|
|
struct ubifs_znode **zn, int *n,
|
|
const struct qstr *nm, int adding)
|
|
{
|
|
struct ubifs_znode *o_znode = NULL, *znode = *zn;
|
|
int uninitialized_var(o_n), err, cmp, unsure = 0, nn = *n;
|
|
|
|
cmp = fallible_matches_name(c, &znode->zbranch[nn], nm);
|
|
if (unlikely(cmp < 0))
|
|
return cmp;
|
|
if (cmp == NAME_MATCHES)
|
|
return 1;
|
|
if (cmp == NOT_ON_MEDIA) {
|
|
o_znode = znode;
|
|
o_n = nn;
|
|
/*
|
|
* We are unlucky and hit a dangling branch straight away.
|
|
* Now we do not really know where to go to find the needed
|
|
* branch - to the left or to the right. Well, let's try left.
|
|
*/
|
|
unsure = 1;
|
|
} else if (!adding)
|
|
unsure = 1; /* Remove a dangling branch wherever it is */
|
|
|
|
if (cmp == NAME_GREATER || unsure) {
|
|
/* Look left */
|
|
while (1) {
|
|
err = tnc_prev(c, zn, n);
|
|
if (err == -ENOENT) {
|
|
ubifs_assert(*n == 0);
|
|
*n = -1;
|
|
break;
|
|
}
|
|
if (err < 0)
|
|
return err;
|
|
if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) {
|
|
/* See comments in 'resolve_collision()' */
|
|
if (*n == (*zn)->child_cnt - 1) {
|
|
err = tnc_next(c, zn, n);
|
|
if (err) {
|
|
/* Should be impossible */
|
|
ubifs_assert(0);
|
|
if (err == -ENOENT)
|
|
err = -EINVAL;
|
|
return err;
|
|
}
|
|
ubifs_assert(*n == 0);
|
|
*n = -1;
|
|
}
|
|
break;
|
|
}
|
|
err = fallible_matches_name(c, &(*zn)->zbranch[*n], nm);
|
|
if (err < 0)
|
|
return err;
|
|
if (err == NAME_MATCHES)
|
|
return 1;
|
|
if (err == NOT_ON_MEDIA) {
|
|
o_znode = *zn;
|
|
o_n = *n;
|
|
continue;
|
|
}
|
|
if (!adding)
|
|
continue;
|
|
if (err == NAME_LESS)
|
|
break;
|
|
else
|
|
unsure = 0;
|
|
}
|
|
}
|
|
|
|
if (cmp == NAME_LESS || unsure) {
|
|
/* Look right */
|
|
*zn = znode;
|
|
*n = nn;
|
|
while (1) {
|
|
err = tnc_next(c, &znode, &nn);
|
|
if (err == -ENOENT)
|
|
break;
|
|
if (err < 0)
|
|
return err;
|
|
if (keys_cmp(c, &znode->zbranch[nn].key, key))
|
|
break;
|
|
err = fallible_matches_name(c, &znode->zbranch[nn], nm);
|
|
if (err < 0)
|
|
return err;
|
|
if (err == NAME_GREATER)
|
|
break;
|
|
*zn = znode;
|
|
*n = nn;
|
|
if (err == NAME_MATCHES)
|
|
return 1;
|
|
if (err == NOT_ON_MEDIA) {
|
|
o_znode = znode;
|
|
o_n = nn;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Never match a dangling branch when adding */
|
|
if (adding || !o_znode)
|
|
return 0;
|
|
|
|
dbg_mnt("dangling match LEB %d:%d len %d %s",
|
|
o_znode->zbranch[o_n].lnum, o_znode->zbranch[o_n].offs,
|
|
o_znode->zbranch[o_n].len, DBGKEY(key));
|
|
*zn = o_znode;
|
|
*n = o_n;
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* matches_position - determine if a zbranch matches a given position.
|
|
* @zbr: zbranch of dent
|
|
* @lnum: LEB number of dent to match
|
|
* @offs: offset of dent to match
|
|
*
|
|
* This function returns %1 if @lnum:@offs matches, and %0 otherwise.
|
|
*/
|
|
static int matches_position(struct ubifs_zbranch *zbr, int lnum, int offs)
|
|
{
|
|
if (zbr->lnum == lnum && zbr->offs == offs)
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* resolve_collision_directly - resolve a collision directly.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key of directory entry
|
|
* @zn: znode is passed and returned here
|
|
* @n: zbranch number is passed and returned here
|
|
* @lnum: LEB number of dent node to match
|
|
* @offs: offset of dent node to match
|
|
*
|
|
* This function is used for "hashed" keys to make sure the found directory or
|
|
* extended attribute entry node is what was looked for. It is used when the
|
|
* flash address of the right node is known (@lnum:@offs) which makes it much
|
|
* easier to resolve collisions (no need to read entries and match full
|
|
* names). This function returns %1 and sets @zn and @n if the collision is
|
|
* resolved, %0 if @lnum:@offs is not found and @zn and @n are set to the
|
|
* previous directory entry. Otherwise a negative error code is returned.
|
|
*/
|
|
static int resolve_collision_directly(struct ubifs_info *c,
|
|
const union ubifs_key *key,
|
|
struct ubifs_znode **zn, int *n,
|
|
int lnum, int offs)
|
|
{
|
|
struct ubifs_znode *znode;
|
|
int nn, err;
|
|
|
|
znode = *zn;
|
|
nn = *n;
|
|
if (matches_position(&znode->zbranch[nn], lnum, offs))
|
|
return 1;
|
|
|
|
/* Look left */
|
|
while (1) {
|
|
err = tnc_prev(c, &znode, &nn);
|
|
if (err == -ENOENT)
|
|
break;
|
|
if (err < 0)
|
|
return err;
|
|
if (keys_cmp(c, &znode->zbranch[nn].key, key))
|
|
break;
|
|
if (matches_position(&znode->zbranch[nn], lnum, offs)) {
|
|
*zn = znode;
|
|
*n = nn;
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
/* Look right */
|
|
znode = *zn;
|
|
nn = *n;
|
|
while (1) {
|
|
err = tnc_next(c, &znode, &nn);
|
|
if (err == -ENOENT)
|
|
return 0;
|
|
if (err < 0)
|
|
return err;
|
|
if (keys_cmp(c, &znode->zbranch[nn].key, key))
|
|
return 0;
|
|
*zn = znode;
|
|
*n = nn;
|
|
if (matches_position(&znode->zbranch[nn], lnum, offs))
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* dirty_cow_bottom_up - dirty a znode and its ancestors.
|
|
* @c: UBIFS file-system description object
|
|
* @znode: znode to dirty
|
|
*
|
|
* If we do not have a unique key that resides in a znode, then we cannot
|
|
* dirty that znode from the top down (i.e. by using lookup_level0_dirty)
|
|
* This function records the path back to the last dirty ancestor, and then
|
|
* dirties the znodes on that path.
|
|
*/
|
|
static struct ubifs_znode *dirty_cow_bottom_up(struct ubifs_info *c,
|
|
struct ubifs_znode *znode)
|
|
{
|
|
struct ubifs_znode *zp;
|
|
int *path = c->bottom_up_buf, p = 0;
|
|
|
|
ubifs_assert(c->zroot.znode);
|
|
ubifs_assert(znode);
|
|
if (c->zroot.znode->level > BOTTOM_UP_HEIGHT) {
|
|
kfree(c->bottom_up_buf);
|
|
c->bottom_up_buf = kmalloc(c->zroot.znode->level * sizeof(int),
|
|
GFP_NOFS);
|
|
if (!c->bottom_up_buf)
|
|
return ERR_PTR(-ENOMEM);
|
|
path = c->bottom_up_buf;
|
|
}
|
|
if (c->zroot.znode->level) {
|
|
/* Go up until parent is dirty */
|
|
while (1) {
|
|
int n;
|
|
|
|
zp = znode->parent;
|
|
if (!zp)
|
|
break;
|
|
n = znode->iip;
|
|
ubifs_assert(p < c->zroot.znode->level);
|
|
path[p++] = n;
|
|
if (!zp->cnext && ubifs_zn_dirty(znode))
|
|
break;
|
|
znode = zp;
|
|
}
|
|
}
|
|
|
|
/* Come back down, dirtying as we go */
|
|
while (1) {
|
|
struct ubifs_zbranch *zbr;
|
|
|
|
zp = znode->parent;
|
|
if (zp) {
|
|
ubifs_assert(path[p - 1] >= 0);
|
|
ubifs_assert(path[p - 1] < zp->child_cnt);
|
|
zbr = &zp->zbranch[path[--p]];
|
|
znode = dirty_cow_znode(c, zbr);
|
|
} else {
|
|
ubifs_assert(znode == c->zroot.znode);
|
|
znode = dirty_cow_znode(c, &c->zroot);
|
|
}
|
|
if (IS_ERR(znode) || !p)
|
|
break;
|
|
ubifs_assert(path[p - 1] >= 0);
|
|
ubifs_assert(path[p - 1] < znode->child_cnt);
|
|
znode = znode->zbranch[path[p - 1]].znode;
|
|
}
|
|
|
|
return znode;
|
|
}
|
|
|
|
/**
|
|
* ubifs_lookup_level0 - search for zero-level znode.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to lookup
|
|
* @zn: znode is returned here
|
|
* @n: znode branch slot number is returned here
|
|
*
|
|
* This function looks up the TNC tree and search for zero-level znode which
|
|
* refers key @key. The found zero-level znode is returned in @zn. There are 3
|
|
* cases:
|
|
* o exact match, i.e. the found zero-level znode contains key @key, then %1
|
|
* is returned and slot number of the matched branch is stored in @n;
|
|
* o not exact match, which means that zero-level znode does not contain
|
|
* @key, then %0 is returned and slot number of the closed branch is stored
|
|
* in @n;
|
|
* o @key is so small that it is even less than the lowest key of the
|
|
* leftmost zero-level node, then %0 is returned and %0 is stored in @n.
|
|
*
|
|
* Note, when the TNC tree is traversed, some znodes may be absent, then this
|
|
* function reads corresponding indexing nodes and inserts them to TNC. In
|
|
* case of failure, a negative error code is returned.
|
|
*/
|
|
int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key,
|
|
struct ubifs_znode **zn, int *n)
|
|
{
|
|
int err, exact;
|
|
struct ubifs_znode *znode;
|
|
unsigned long time = get_seconds();
|
|
|
|
dbg_tnc("search key %s", DBGKEY(key));
|
|
|
|
znode = c->zroot.znode;
|
|
if (unlikely(!znode)) {
|
|
znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
}
|
|
|
|
znode->time = time;
|
|
|
|
while (1) {
|
|
struct ubifs_zbranch *zbr;
|
|
|
|
exact = ubifs_search_zbranch(c, znode, key, n);
|
|
|
|
if (znode->level == 0)
|
|
break;
|
|
|
|
if (*n < 0)
|
|
*n = 0;
|
|
zbr = &znode->zbranch[*n];
|
|
|
|
if (zbr->znode) {
|
|
znode->time = time;
|
|
znode = zbr->znode;
|
|
continue;
|
|
}
|
|
|
|
/* znode is not in TNC cache, load it from the media */
|
|
znode = ubifs_load_znode(c, zbr, znode, *n);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
}
|
|
|
|
*zn = znode;
|
|
if (exact || !is_hash_key(c, key) || *n != -1) {
|
|
dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n);
|
|
return exact;
|
|
}
|
|
|
|
/*
|
|
* Here is a tricky place. We have not found the key and this is a
|
|
* "hashed" key, which may collide. The rest of the code deals with
|
|
* situations like this:
|
|
*
|
|
* | 3 | 5 |
|
|
* / \
|
|
* | 3 | 5 | | 6 | 7 | (x)
|
|
*
|
|
* Or more a complex example:
|
|
*
|
|
* | 1 | 5 |
|
|
* / \
|
|
* | 1 | 3 | | 5 | 8 |
|
|
* \ /
|
|
* | 5 | 5 | | 6 | 7 | (x)
|
|
*
|
|
* In the examples, if we are looking for key "5", we may reach nodes
|
|
* marked with "(x)". In this case what we have do is to look at the
|
|
* left and see if there is "5" key there. If there is, we have to
|
|
* return it.
|
|
*
|
|
* Note, this whole situation is possible because we allow to have
|
|
* elements which are equivalent to the next key in the parent in the
|
|
* children of current znode. For example, this happens if we split a
|
|
* znode like this: | 3 | 5 | 5 | 6 | 7 |, which results in something
|
|
* like this:
|
|
* | 3 | 5 |
|
|
* / \
|
|
* | 3 | 5 | | 5 | 6 | 7 |
|
|
* ^
|
|
* And this becomes what is at the first "picture" after key "5" marked
|
|
* with "^" is removed. What could be done is we could prohibit
|
|
* splitting in the middle of the colliding sequence. Also, when
|
|
* removing the leftmost key, we would have to correct the key of the
|
|
* parent node, which would introduce additional complications. Namely,
|
|
* if we changed the leftmost key of the parent znode, the garbage
|
|
* collector would be unable to find it (GC is doing this when GC'ing
|
|
* indexing LEBs). Although we already have an additional RB-tree where
|
|
* we save such changed znodes (see 'ins_clr_old_idx_znode()') until
|
|
* after the commit. But anyway, this does not look easy to implement
|
|
* so we did not try this.
|
|
*/
|
|
err = tnc_prev(c, &znode, n);
|
|
if (err == -ENOENT) {
|
|
dbg_tnc("found 0, lvl %d, n -1", znode->level);
|
|
*n = -1;
|
|
return 0;
|
|
}
|
|
if (unlikely(err < 0))
|
|
return err;
|
|
if (keys_cmp(c, key, &znode->zbranch[*n].key)) {
|
|
dbg_tnc("found 0, lvl %d, n -1", znode->level);
|
|
*n = -1;
|
|
return 0;
|
|
}
|
|
|
|
dbg_tnc("found 1, lvl %d, n %d", znode->level, *n);
|
|
*zn = znode;
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* lookup_level0_dirty - search for zero-level znode dirtying.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to lookup
|
|
* @zn: znode is returned here
|
|
* @n: znode branch slot number is returned here
|
|
*
|
|
* This function looks up the TNC tree and search for zero-level znode which
|
|
* refers key @key. The found zero-level znode is returned in @zn. There are 3
|
|
* cases:
|
|
* o exact match, i.e. the found zero-level znode contains key @key, then %1
|
|
* is returned and slot number of the matched branch is stored in @n;
|
|
* o not exact match, which means that zero-level znode does not contain @key
|
|
* then %0 is returned and slot number of the closed branch is stored in
|
|
* @n;
|
|
* o @key is so small that it is even less than the lowest key of the
|
|
* leftmost zero-level node, then %0 is returned and %-1 is stored in @n.
|
|
*
|
|
* Additionally all znodes in the path from the root to the located zero-level
|
|
* znode are marked as dirty.
|
|
*
|
|
* Note, when the TNC tree is traversed, some znodes may be absent, then this
|
|
* function reads corresponding indexing nodes and inserts them to TNC. In
|
|
* case of failure, a negative error code is returned.
|
|
*/
|
|
static int lookup_level0_dirty(struct ubifs_info *c, const union ubifs_key *key,
|
|
struct ubifs_znode **zn, int *n)
|
|
{
|
|
int err, exact;
|
|
struct ubifs_znode *znode;
|
|
unsigned long time = get_seconds();
|
|
|
|
dbg_tnc("search and dirty key %s", DBGKEY(key));
|
|
|
|
znode = c->zroot.znode;
|
|
if (unlikely(!znode)) {
|
|
znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
}
|
|
|
|
znode = dirty_cow_znode(c, &c->zroot);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
|
|
znode->time = time;
|
|
|
|
while (1) {
|
|
struct ubifs_zbranch *zbr;
|
|
|
|
exact = ubifs_search_zbranch(c, znode, key, n);
|
|
|
|
if (znode->level == 0)
|
|
break;
|
|
|
|
if (*n < 0)
|
|
*n = 0;
|
|
zbr = &znode->zbranch[*n];
|
|
|
|
if (zbr->znode) {
|
|
znode->time = time;
|
|
znode = dirty_cow_znode(c, zbr);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
continue;
|
|
}
|
|
|
|
/* znode is not in TNC cache, load it from the media */
|
|
znode = ubifs_load_znode(c, zbr, znode, *n);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
znode = dirty_cow_znode(c, zbr);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
}
|
|
|
|
*zn = znode;
|
|
if (exact || !is_hash_key(c, key) || *n != -1) {
|
|
dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n);
|
|
return exact;
|
|
}
|
|
|
|
/*
|
|
* See huge comment at 'lookup_level0_dirty()' what is the rest of the
|
|
* code.
|
|
*/
|
|
err = tnc_prev(c, &znode, n);
|
|
if (err == -ENOENT) {
|
|
*n = -1;
|
|
dbg_tnc("found 0, lvl %d, n -1", znode->level);
|
|
return 0;
|
|
}
|
|
if (unlikely(err < 0))
|
|
return err;
|
|
if (keys_cmp(c, key, &znode->zbranch[*n].key)) {
|
|
*n = -1;
|
|
dbg_tnc("found 0, lvl %d, n -1", znode->level);
|
|
return 0;
|
|
}
|
|
|
|
if (znode->cnext || !ubifs_zn_dirty(znode)) {
|
|
znode = dirty_cow_bottom_up(c, znode);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
}
|
|
|
|
dbg_tnc("found 1, lvl %d, n %d", znode->level, *n);
|
|
*zn = znode;
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* maybe_leb_gced - determine if a LEB may have been garbage collected.
|
|
* @c: UBIFS file-system description object
|
|
* @lnum: LEB number
|
|
* @gc_seq1: garbage collection sequence number
|
|
*
|
|
* This function determines if @lnum may have been garbage collected since
|
|
* sequence number @gc_seq1. If it may have been then %1 is returned, otherwise
|
|
* %0 is returned.
|
|
*/
|
|
static int maybe_leb_gced(struct ubifs_info *c, int lnum, int gc_seq1)
|
|
{
|
|
int gc_seq2, gced_lnum;
|
|
|
|
gced_lnum = c->gced_lnum;
|
|
smp_rmb();
|
|
gc_seq2 = c->gc_seq;
|
|
/* Same seq means no GC */
|
|
if (gc_seq1 == gc_seq2)
|
|
return 0;
|
|
/* Different by more than 1 means we don't know */
|
|
if (gc_seq1 + 1 != gc_seq2)
|
|
return 1;
|
|
/*
|
|
* We have seen the sequence number has increased by 1. Now we need to
|
|
* be sure we read the right LEB number, so read it again.
|
|
*/
|
|
smp_rmb();
|
|
if (gced_lnum != c->gced_lnum)
|
|
return 1;
|
|
/* Finally we can check lnum */
|
|
if (gced_lnum == lnum)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_locate - look up a file-system node and return it and its location.
|
|
* @c: UBIFS file-system description object
|
|
* @key: node key to lookup
|
|
* @node: the node is returned here
|
|
* @lnum: LEB number is returned here
|
|
* @offs: offset is returned here
|
|
*
|
|
* This function look up and reads node with key @key. The caller has to make
|
|
* sure the @node buffer is large enough to fit the node. Returns zero in case
|
|
* of success, %-ENOENT if the node was not found, and a negative error code in
|
|
* case of failure. The node location can be returned in @lnum and @offs.
|
|
*/
|
|
int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key,
|
|
void *node, int *lnum, int *offs)
|
|
{
|
|
int found, n, err, safely = 0, gc_seq1;
|
|
struct ubifs_znode *znode;
|
|
struct ubifs_zbranch zbr, *zt;
|
|
|
|
again:
|
|
mutex_lock(&c->tnc_mutex);
|
|
found = ubifs_lookup_level0(c, key, &znode, &n);
|
|
if (!found) {
|
|
err = -ENOENT;
|
|
goto out;
|
|
} else if (found < 0) {
|
|
err = found;
|
|
goto out;
|
|
}
|
|
zt = &znode->zbranch[n];
|
|
if (lnum) {
|
|
*lnum = zt->lnum;
|
|
*offs = zt->offs;
|
|
}
|
|
if (is_hash_key(c, key)) {
|
|
/*
|
|
* In this case the leaf node cache gets used, so we pass the
|
|
* address of the zbranch and keep the mutex locked
|
|
*/
|
|
err = tnc_read_node_nm(c, zt, node);
|
|
goto out;
|
|
}
|
|
if (safely) {
|
|
err = ubifs_tnc_read_node(c, zt, node);
|
|
goto out;
|
|
}
|
|
/* Drop the TNC mutex prematurely and race with garbage collection */
|
|
zbr = znode->zbranch[n];
|
|
gc_seq1 = c->gc_seq;
|
|
mutex_unlock(&c->tnc_mutex);
|
|
|
|
if (ubifs_get_wbuf(c, zbr.lnum)) {
|
|
/* We do not GC journal heads */
|
|
err = ubifs_tnc_read_node(c, &zbr, node);
|
|
return err;
|
|
}
|
|
|
|
err = fallible_read_node(c, key, &zbr, node);
|
|
if (err <= 0 || maybe_leb_gced(c, zbr.lnum, gc_seq1)) {
|
|
/*
|
|
* The node may have been GC'ed out from under us so try again
|
|
* while keeping the TNC mutex locked.
|
|
*/
|
|
safely = 1;
|
|
goto again;
|
|
}
|
|
return 0;
|
|
|
|
out:
|
|
mutex_unlock(&c->tnc_mutex);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_get_bu_keys - lookup keys for bulk-read.
|
|
* @c: UBIFS file-system description object
|
|
* @bu: bulk-read parameters and results
|
|
*
|
|
* Lookup consecutive data node keys for the same inode that reside
|
|
* consecutively in the same LEB. This function returns zero in case of success
|
|
* and a negative error code in case of failure.
|
|
*
|
|
* Note, if the bulk-read buffer length (@bu->buf_len) is known, this function
|
|
* makes sure bulk-read nodes fit the buffer. Otherwise, this function prepares
|
|
* maximum possible amount of nodes for bulk-read.
|
|
*/
|
|
int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu)
|
|
{
|
|
int n, err = 0, lnum = -1, uninitialized_var(offs);
|
|
int uninitialized_var(len);
|
|
unsigned int block = key_block(c, &bu->key);
|
|
struct ubifs_znode *znode;
|
|
|
|
bu->cnt = 0;
|
|
bu->blk_cnt = 0;
|
|
bu->eof = 0;
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
/* Find first key */
|
|
err = ubifs_lookup_level0(c, &bu->key, &znode, &n);
|
|
if (err < 0)
|
|
goto out;
|
|
if (err) {
|
|
/* Key found */
|
|
len = znode->zbranch[n].len;
|
|
/* The buffer must be big enough for at least 1 node */
|
|
if (len > bu->buf_len) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
/* Add this key */
|
|
bu->zbranch[bu->cnt++] = znode->zbranch[n];
|
|
bu->blk_cnt += 1;
|
|
lnum = znode->zbranch[n].lnum;
|
|
offs = ALIGN(znode->zbranch[n].offs + len, 8);
|
|
}
|
|
while (1) {
|
|
struct ubifs_zbranch *zbr;
|
|
union ubifs_key *key;
|
|
unsigned int next_block;
|
|
|
|
/* Find next key */
|
|
err = tnc_next(c, &znode, &n);
|
|
if (err)
|
|
goto out;
|
|
zbr = &znode->zbranch[n];
|
|
key = &zbr->key;
|
|
/* See if there is another data key for this file */
|
|
if (key_inum(c, key) != key_inum(c, &bu->key) ||
|
|
key_type(c, key) != UBIFS_DATA_KEY) {
|
|
err = -ENOENT;
|
|
goto out;
|
|
}
|
|
if (lnum < 0) {
|
|
/* First key found */
|
|
lnum = zbr->lnum;
|
|
offs = ALIGN(zbr->offs + zbr->len, 8);
|
|
len = zbr->len;
|
|
if (len > bu->buf_len) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
} else {
|
|
/*
|
|
* The data nodes must be in consecutive positions in
|
|
* the same LEB.
|
|
*/
|
|
if (zbr->lnum != lnum || zbr->offs != offs)
|
|
goto out;
|
|
offs += ALIGN(zbr->len, 8);
|
|
len = ALIGN(len, 8) + zbr->len;
|
|
/* Must not exceed buffer length */
|
|
if (len > bu->buf_len)
|
|
goto out;
|
|
}
|
|
/* Allow for holes */
|
|
next_block = key_block(c, key);
|
|
bu->blk_cnt += (next_block - block - 1);
|
|
if (bu->blk_cnt >= UBIFS_MAX_BULK_READ)
|
|
goto out;
|
|
block = next_block;
|
|
/* Add this key */
|
|
bu->zbranch[bu->cnt++] = *zbr;
|
|
bu->blk_cnt += 1;
|
|
/* See if we have room for more */
|
|
if (bu->cnt >= UBIFS_MAX_BULK_READ)
|
|
goto out;
|
|
if (bu->blk_cnt >= UBIFS_MAX_BULK_READ)
|
|
goto out;
|
|
}
|
|
out:
|
|
if (err == -ENOENT) {
|
|
bu->eof = 1;
|
|
err = 0;
|
|
}
|
|
bu->gc_seq = c->gc_seq;
|
|
mutex_unlock(&c->tnc_mutex);
|
|
if (err)
|
|
return err;
|
|
/*
|
|
* An enormous hole could cause bulk-read to encompass too many
|
|
* page cache pages, so limit the number here.
|
|
*/
|
|
if (bu->blk_cnt > UBIFS_MAX_BULK_READ)
|
|
bu->blk_cnt = UBIFS_MAX_BULK_READ;
|
|
/*
|
|
* Ensure that bulk-read covers a whole number of page cache
|
|
* pages.
|
|
*/
|
|
if (UBIFS_BLOCKS_PER_PAGE == 1 ||
|
|
!(bu->blk_cnt & (UBIFS_BLOCKS_PER_PAGE - 1)))
|
|
return 0;
|
|
if (bu->eof) {
|
|
/* At the end of file we can round up */
|
|
bu->blk_cnt += UBIFS_BLOCKS_PER_PAGE - 1;
|
|
return 0;
|
|
}
|
|
/* Exclude data nodes that do not make up a whole page cache page */
|
|
block = key_block(c, &bu->key) + bu->blk_cnt;
|
|
block &= ~(UBIFS_BLOCKS_PER_PAGE - 1);
|
|
while (bu->cnt) {
|
|
if (key_block(c, &bu->zbranch[bu->cnt - 1].key) < block)
|
|
break;
|
|
bu->cnt -= 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* read_wbuf - bulk-read from a LEB with a wbuf.
|
|
* @wbuf: wbuf that may overlap the read
|
|
* @buf: buffer into which to read
|
|
* @len: read length
|
|
* @lnum: LEB number from which to read
|
|
* @offs: offset from which to read
|
|
*
|
|
* This functions returns %0 on success or a negative error code on failure.
|
|
*/
|
|
static int read_wbuf(struct ubifs_wbuf *wbuf, void *buf, int len, int lnum,
|
|
int offs)
|
|
{
|
|
const struct ubifs_info *c = wbuf->c;
|
|
int rlen, overlap;
|
|
|
|
dbg_io("LEB %d:%d, length %d", lnum, offs, len);
|
|
ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
|
|
ubifs_assert(!(offs & 7) && offs < c->leb_size);
|
|
ubifs_assert(offs + len <= c->leb_size);
|
|
|
|
spin_lock(&wbuf->lock);
|
|
overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs);
|
|
if (!overlap) {
|
|
/* We may safely unlock the write-buffer and read the data */
|
|
spin_unlock(&wbuf->lock);
|
|
return ubi_read(c->ubi, lnum, buf, offs, len);
|
|
}
|
|
|
|
/* Don't read under wbuf */
|
|
rlen = wbuf->offs - offs;
|
|
if (rlen < 0)
|
|
rlen = 0;
|
|
|
|
/* Copy the rest from the write-buffer */
|
|
memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen);
|
|
spin_unlock(&wbuf->lock);
|
|
|
|
if (rlen > 0)
|
|
/* Read everything that goes before write-buffer */
|
|
return ubi_read(c->ubi, lnum, buf, offs, rlen);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* validate_data_node - validate data nodes for bulk-read.
|
|
* @c: UBIFS file-system description object
|
|
* @buf: buffer containing data node to validate
|
|
* @zbr: zbranch of data node to validate
|
|
*
|
|
* This functions returns %0 on success or a negative error code on failure.
|
|
*/
|
|
static int validate_data_node(struct ubifs_info *c, void *buf,
|
|
struct ubifs_zbranch *zbr)
|
|
{
|
|
union ubifs_key key1;
|
|
struct ubifs_ch *ch = buf;
|
|
int err, len;
|
|
|
|
if (ch->node_type != UBIFS_DATA_NODE) {
|
|
ubifs_err("bad node type (%d but expected %d)",
|
|
ch->node_type, UBIFS_DATA_NODE);
|
|
goto out_err;
|
|
}
|
|
|
|
err = ubifs_check_node(c, buf, zbr->lnum, zbr->offs, 0, 0);
|
|
if (err) {
|
|
ubifs_err("expected node type %d", UBIFS_DATA_NODE);
|
|
goto out;
|
|
}
|
|
|
|
len = le32_to_cpu(ch->len);
|
|
if (len != zbr->len) {
|
|
ubifs_err("bad node length %d, expected %d", len, zbr->len);
|
|
goto out_err;
|
|
}
|
|
|
|
/* Make sure the key of the read node is correct */
|
|
key_read(c, buf + UBIFS_KEY_OFFSET, &key1);
|
|
if (!keys_eq(c, &zbr->key, &key1)) {
|
|
ubifs_err("bad key in node at LEB %d:%d",
|
|
zbr->lnum, zbr->offs);
|
|
dbg_tnc("looked for key %s found node's key %s",
|
|
DBGKEY(&zbr->key), DBGKEY1(&key1));
|
|
goto out_err;
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_err:
|
|
err = -EINVAL;
|
|
out:
|
|
ubifs_err("bad node at LEB %d:%d", zbr->lnum, zbr->offs);
|
|
dbg_dump_node(c, buf);
|
|
dbg_dump_stack();
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_bulk_read - read a number of data nodes in one go.
|
|
* @c: UBIFS file-system description object
|
|
* @bu: bulk-read parameters and results
|
|
*
|
|
* This functions reads and validates the data nodes that were identified by the
|
|
* 'ubifs_tnc_get_bu_keys()' function. This functions returns %0 on success,
|
|
* -EAGAIN to indicate a race with GC, or another negative error code on
|
|
* failure.
|
|
*/
|
|
int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu)
|
|
{
|
|
int lnum = bu->zbranch[0].lnum, offs = bu->zbranch[0].offs, len, err, i;
|
|
struct ubifs_wbuf *wbuf;
|
|
void *buf;
|
|
|
|
len = bu->zbranch[bu->cnt - 1].offs;
|
|
len += bu->zbranch[bu->cnt - 1].len - offs;
|
|
if (len > bu->buf_len) {
|
|
ubifs_err("buffer too small %d vs %d", bu->buf_len, len);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Do the read */
|
|
wbuf = ubifs_get_wbuf(c, lnum);
|
|
if (wbuf)
|
|
err = read_wbuf(wbuf, bu->buf, len, lnum, offs);
|
|
else
|
|
err = ubi_read(c->ubi, lnum, bu->buf, offs, len);
|
|
|
|
/* Check for a race with GC */
|
|
if (maybe_leb_gced(c, lnum, bu->gc_seq))
|
|
return -EAGAIN;
|
|
|
|
if (err && err != -EBADMSG) {
|
|
ubifs_err("failed to read from LEB %d:%d, error %d",
|
|
lnum, offs, err);
|
|
dbg_dump_stack();
|
|
dbg_tnc("key %s", DBGKEY(&bu->key));
|
|
return err;
|
|
}
|
|
|
|
/* Validate the nodes read */
|
|
buf = bu->buf;
|
|
for (i = 0; i < bu->cnt; i++) {
|
|
err = validate_data_node(c, buf, &bu->zbranch[i]);
|
|
if (err)
|
|
return err;
|
|
buf = buf + ALIGN(bu->zbranch[i].len, 8);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* do_lookup_nm- look up a "hashed" node.
|
|
* @c: UBIFS file-system description object
|
|
* @key: node key to lookup
|
|
* @node: the node is returned here
|
|
* @nm: node name
|
|
*
|
|
* This function look up and reads a node which contains name hash in the key.
|
|
* Since the hash may have collisions, there may be many nodes with the same
|
|
* key, so we have to sequentially look to all of them until the needed one is
|
|
* found. This function returns zero in case of success, %-ENOENT if the node
|
|
* was not found, and a negative error code in case of failure.
|
|
*/
|
|
static int do_lookup_nm(struct ubifs_info *c, const union ubifs_key *key,
|
|
void *node, const struct qstr *nm)
|
|
{
|
|
int found, n, err;
|
|
struct ubifs_znode *znode;
|
|
|
|
dbg_tnc("name '%.*s' key %s", nm->len, nm->name, DBGKEY(key));
|
|
mutex_lock(&c->tnc_mutex);
|
|
found = ubifs_lookup_level0(c, key, &znode, &n);
|
|
if (!found) {
|
|
err = -ENOENT;
|
|
goto out_unlock;
|
|
} else if (found < 0) {
|
|
err = found;
|
|
goto out_unlock;
|
|
}
|
|
|
|
ubifs_assert(n >= 0);
|
|
|
|
err = resolve_collision(c, key, &znode, &n, nm);
|
|
dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n);
|
|
if (unlikely(err < 0))
|
|
goto out_unlock;
|
|
if (err == 0) {
|
|
err = -ENOENT;
|
|
goto out_unlock;
|
|
}
|
|
|
|
err = tnc_read_node_nm(c, &znode->zbranch[n], node);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&c->tnc_mutex);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_lookup_nm - look up a "hashed" node.
|
|
* @c: UBIFS file-system description object
|
|
* @key: node key to lookup
|
|
* @node: the node is returned here
|
|
* @nm: node name
|
|
*
|
|
* This function look up and reads a node which contains name hash in the key.
|
|
* Since the hash may have collisions, there may be many nodes with the same
|
|
* key, so we have to sequentially look to all of them until the needed one is
|
|
* found. This function returns zero in case of success, %-ENOENT if the node
|
|
* was not found, and a negative error code in case of failure.
|
|
*/
|
|
int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key,
|
|
void *node, const struct qstr *nm)
|
|
{
|
|
int err, len;
|
|
const struct ubifs_dent_node *dent = node;
|
|
|
|
/*
|
|
* We assume that in most of the cases there are no name collisions and
|
|
* 'ubifs_tnc_lookup()' returns us the right direntry.
|
|
*/
|
|
err = ubifs_tnc_lookup(c, key, node);
|
|
if (err)
|
|
return err;
|
|
|
|
len = le16_to_cpu(dent->nlen);
|
|
if (nm->len == len && !memcmp(dent->name, nm->name, len))
|
|
return 0;
|
|
|
|
/*
|
|
* Unluckily, there are hash collisions and we have to iterate over
|
|
* them look at each direntry with colliding name hash sequentially.
|
|
*/
|
|
return do_lookup_nm(c, key, node, nm);
|
|
}
|
|
|
|
/**
|
|
* correct_parent_keys - correct parent znodes' keys.
|
|
* @c: UBIFS file-system description object
|
|
* @znode: znode to correct parent znodes for
|
|
*
|
|
* This is a helper function for 'tnc_insert()'. When the key of the leftmost
|
|
* zbranch changes, keys of parent znodes have to be corrected. This helper
|
|
* function is called in such situations and corrects the keys if needed.
|
|
*/
|
|
static void correct_parent_keys(const struct ubifs_info *c,
|
|
struct ubifs_znode *znode)
|
|
{
|
|
union ubifs_key *key, *key1;
|
|
|
|
ubifs_assert(znode->parent);
|
|
ubifs_assert(znode->iip == 0);
|
|
|
|
key = &znode->zbranch[0].key;
|
|
key1 = &znode->parent->zbranch[0].key;
|
|
|
|
while (keys_cmp(c, key, key1) < 0) {
|
|
key_copy(c, key, key1);
|
|
znode = znode->parent;
|
|
znode->alt = 1;
|
|
if (!znode->parent || znode->iip)
|
|
break;
|
|
key1 = &znode->parent->zbranch[0].key;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* insert_zbranch - insert a zbranch into a znode.
|
|
* @znode: znode into which to insert
|
|
* @zbr: zbranch to insert
|
|
* @n: slot number to insert to
|
|
*
|
|
* This is a helper function for 'tnc_insert()'. UBIFS does not allow "gaps" in
|
|
* znode's array of zbranches and keeps zbranches consolidated, so when a new
|
|
* zbranch has to be inserted to the @znode->zbranches[]' array at the @n-th
|
|
* slot, zbranches starting from @n have to be moved right.
|
|
*/
|
|
static void insert_zbranch(struct ubifs_znode *znode,
|
|
const struct ubifs_zbranch *zbr, int n)
|
|
{
|
|
int i;
|
|
|
|
ubifs_assert(ubifs_zn_dirty(znode));
|
|
|
|
if (znode->level) {
|
|
for (i = znode->child_cnt; i > n; i--) {
|
|
znode->zbranch[i] = znode->zbranch[i - 1];
|
|
if (znode->zbranch[i].znode)
|
|
znode->zbranch[i].znode->iip = i;
|
|
}
|
|
if (zbr->znode)
|
|
zbr->znode->iip = n;
|
|
} else
|
|
for (i = znode->child_cnt; i > n; i--)
|
|
znode->zbranch[i] = znode->zbranch[i - 1];
|
|
|
|
znode->zbranch[n] = *zbr;
|
|
znode->child_cnt += 1;
|
|
|
|
/*
|
|
* After inserting at slot zero, the lower bound of the key range of
|
|
* this znode may have changed. If this znode is subsequently split
|
|
* then the upper bound of the key range may change, and furthermore
|
|
* it could change to be lower than the original lower bound. If that
|
|
* happens, then it will no longer be possible to find this znode in the
|
|
* TNC using the key from the index node on flash. That is bad because
|
|
* if it is not found, we will assume it is obsolete and may overwrite
|
|
* it. Then if there is an unclean unmount, we will start using the
|
|
* old index which will be broken.
|
|
*
|
|
* So we first mark znodes that have insertions at slot zero, and then
|
|
* if they are split we add their lnum/offs to the old_idx tree.
|
|
*/
|
|
if (n == 0)
|
|
znode->alt = 1;
|
|
}
|
|
|
|
/**
|
|
* tnc_insert - insert a node into TNC.
|
|
* @c: UBIFS file-system description object
|
|
* @znode: znode to insert into
|
|
* @zbr: branch to insert
|
|
* @n: slot number to insert new zbranch to
|
|
*
|
|
* This function inserts a new node described by @zbr into znode @znode. If
|
|
* znode does not have a free slot for new zbranch, it is split. Parent znodes
|
|
* are splat as well if needed. Returns zero in case of success or a negative
|
|
* error code in case of failure.
|
|
*/
|
|
static int tnc_insert(struct ubifs_info *c, struct ubifs_znode *znode,
|
|
struct ubifs_zbranch *zbr, int n)
|
|
{
|
|
struct ubifs_znode *zn, *zi, *zp;
|
|
int i, keep, move, appending = 0;
|
|
union ubifs_key *key = &zbr->key, *key1;
|
|
|
|
ubifs_assert(n >= 0 && n <= c->fanout);
|
|
|
|
/* Implement naive insert for now */
|
|
again:
|
|
zp = znode->parent;
|
|
if (znode->child_cnt < c->fanout) {
|
|
ubifs_assert(n != c->fanout);
|
|
dbg_tnc("inserted at %d level %d, key %s", n, znode->level,
|
|
DBGKEY(key));
|
|
|
|
insert_zbranch(znode, zbr, n);
|
|
|
|
/* Ensure parent's key is correct */
|
|
if (n == 0 && zp && znode->iip == 0)
|
|
correct_parent_keys(c, znode);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Unfortunately, @znode does not have more empty slots and we have to
|
|
* split it.
|
|
*/
|
|
dbg_tnc("splitting level %d, key %s", znode->level, DBGKEY(key));
|
|
|
|
if (znode->alt)
|
|
/*
|
|
* We can no longer be sure of finding this znode by key, so we
|
|
* record it in the old_idx tree.
|
|
*/
|
|
ins_clr_old_idx_znode(c, znode);
|
|
|
|
zn = kzalloc(c->max_znode_sz, GFP_NOFS);
|
|
if (!zn)
|
|
return -ENOMEM;
|
|
zn->parent = zp;
|
|
zn->level = znode->level;
|
|
|
|
/* Decide where to split */
|
|
if (znode->level == 0 && key_type(c, key) == UBIFS_DATA_KEY) {
|
|
/* Try not to split consecutive data keys */
|
|
if (n == c->fanout) {
|
|
key1 = &znode->zbranch[n - 1].key;
|
|
if (key_inum(c, key1) == key_inum(c, key) &&
|
|
key_type(c, key1) == UBIFS_DATA_KEY)
|
|
appending = 1;
|
|
} else
|
|
goto check_split;
|
|
} else if (appending && n != c->fanout) {
|
|
/* Try not to split consecutive data keys */
|
|
appending = 0;
|
|
check_split:
|
|
if (n >= (c->fanout + 1) / 2) {
|
|
key1 = &znode->zbranch[0].key;
|
|
if (key_inum(c, key1) == key_inum(c, key) &&
|
|
key_type(c, key1) == UBIFS_DATA_KEY) {
|
|
key1 = &znode->zbranch[n].key;
|
|
if (key_inum(c, key1) != key_inum(c, key) ||
|
|
key_type(c, key1) != UBIFS_DATA_KEY) {
|
|
keep = n;
|
|
move = c->fanout - keep;
|
|
zi = znode;
|
|
goto do_split;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (appending) {
|
|
keep = c->fanout;
|
|
move = 0;
|
|
} else {
|
|
keep = (c->fanout + 1) / 2;
|
|
move = c->fanout - keep;
|
|
}
|
|
|
|
/*
|
|
* Although we don't at present, we could look at the neighbors and see
|
|
* if we can move some zbranches there.
|
|
*/
|
|
|
|
if (n < keep) {
|
|
/* Insert into existing znode */
|
|
zi = znode;
|
|
move += 1;
|
|
keep -= 1;
|
|
} else {
|
|
/* Insert into new znode */
|
|
zi = zn;
|
|
n -= keep;
|
|
/* Re-parent */
|
|
if (zn->level != 0)
|
|
zbr->znode->parent = zn;
|
|
}
|
|
|
|
do_split:
|
|
|
|
__set_bit(DIRTY_ZNODE, &zn->flags);
|
|
atomic_long_inc(&c->dirty_zn_cnt);
|
|
|
|
zn->child_cnt = move;
|
|
znode->child_cnt = keep;
|
|
|
|
dbg_tnc("moving %d, keeping %d", move, keep);
|
|
|
|
/* Move zbranch */
|
|
for (i = 0; i < move; i++) {
|
|
zn->zbranch[i] = znode->zbranch[keep + i];
|
|
/* Re-parent */
|
|
if (zn->level != 0)
|
|
if (zn->zbranch[i].znode) {
|
|
zn->zbranch[i].znode->parent = zn;
|
|
zn->zbranch[i].znode->iip = i;
|
|
}
|
|
}
|
|
|
|
/* Insert new key and branch */
|
|
dbg_tnc("inserting at %d level %d, key %s", n, zn->level, DBGKEY(key));
|
|
|
|
insert_zbranch(zi, zbr, n);
|
|
|
|
/* Insert new znode (produced by spitting) into the parent */
|
|
if (zp) {
|
|
if (n == 0 && zi == znode && znode->iip == 0)
|
|
correct_parent_keys(c, znode);
|
|
|
|
/* Locate insertion point */
|
|
n = znode->iip + 1;
|
|
|
|
/* Tail recursion */
|
|
zbr->key = zn->zbranch[0].key;
|
|
zbr->znode = zn;
|
|
zbr->lnum = 0;
|
|
zbr->offs = 0;
|
|
zbr->len = 0;
|
|
znode = zp;
|
|
|
|
goto again;
|
|
}
|
|
|
|
/* We have to split root znode */
|
|
dbg_tnc("creating new zroot at level %d", znode->level + 1);
|
|
|
|
zi = kzalloc(c->max_znode_sz, GFP_NOFS);
|
|
if (!zi)
|
|
return -ENOMEM;
|
|
|
|
zi->child_cnt = 2;
|
|
zi->level = znode->level + 1;
|
|
|
|
__set_bit(DIRTY_ZNODE, &zi->flags);
|
|
atomic_long_inc(&c->dirty_zn_cnt);
|
|
|
|
zi->zbranch[0].key = znode->zbranch[0].key;
|
|
zi->zbranch[0].znode = znode;
|
|
zi->zbranch[0].lnum = c->zroot.lnum;
|
|
zi->zbranch[0].offs = c->zroot.offs;
|
|
zi->zbranch[0].len = c->zroot.len;
|
|
zi->zbranch[1].key = zn->zbranch[0].key;
|
|
zi->zbranch[1].znode = zn;
|
|
|
|
c->zroot.lnum = 0;
|
|
c->zroot.offs = 0;
|
|
c->zroot.len = 0;
|
|
c->zroot.znode = zi;
|
|
|
|
zn->parent = zi;
|
|
zn->iip = 1;
|
|
znode->parent = zi;
|
|
znode->iip = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_add - add a node to TNC.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to add
|
|
* @lnum: LEB number of node
|
|
* @offs: node offset
|
|
* @len: node length
|
|
*
|
|
* This function adds a node with key @key to TNC. The node may be new or it may
|
|
* obsolete some existing one. Returns %0 on success or negative error code on
|
|
* failure.
|
|
*/
|
|
int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum,
|
|
int offs, int len)
|
|
{
|
|
int found, n, err = 0;
|
|
struct ubifs_znode *znode;
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
dbg_tnc("%d:%d, len %d, key %s", lnum, offs, len, DBGKEY(key));
|
|
found = lookup_level0_dirty(c, key, &znode, &n);
|
|
if (!found) {
|
|
struct ubifs_zbranch zbr;
|
|
|
|
zbr.znode = NULL;
|
|
zbr.lnum = lnum;
|
|
zbr.offs = offs;
|
|
zbr.len = len;
|
|
key_copy(c, key, &zbr.key);
|
|
err = tnc_insert(c, znode, &zbr, n + 1);
|
|
} else if (found == 1) {
|
|
struct ubifs_zbranch *zbr = &znode->zbranch[n];
|
|
|
|
lnc_free(zbr);
|
|
err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
|
|
zbr->lnum = lnum;
|
|
zbr->offs = offs;
|
|
zbr->len = len;
|
|
} else
|
|
err = found;
|
|
if (!err)
|
|
err = dbg_check_tnc(c, 0);
|
|
mutex_unlock(&c->tnc_mutex);
|
|
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_replace - replace a node in the TNC only if the old node is found.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to add
|
|
* @old_lnum: LEB number of old node
|
|
* @old_offs: old node offset
|
|
* @lnum: LEB number of node
|
|
* @offs: node offset
|
|
* @len: node length
|
|
*
|
|
* This function replaces a node with key @key in the TNC only if the old node
|
|
* is found. This function is called by garbage collection when node are moved.
|
|
* Returns %0 on success or negative error code on failure.
|
|
*/
|
|
int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key,
|
|
int old_lnum, int old_offs, int lnum, int offs, int len)
|
|
{
|
|
int found, n, err = 0;
|
|
struct ubifs_znode *znode;
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
dbg_tnc("old LEB %d:%d, new LEB %d:%d, len %d, key %s", old_lnum,
|
|
old_offs, lnum, offs, len, DBGKEY(key));
|
|
found = lookup_level0_dirty(c, key, &znode, &n);
|
|
if (found < 0) {
|
|
err = found;
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (found == 1) {
|
|
struct ubifs_zbranch *zbr = &znode->zbranch[n];
|
|
|
|
found = 0;
|
|
if (zbr->lnum == old_lnum && zbr->offs == old_offs) {
|
|
lnc_free(zbr);
|
|
err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
|
|
if (err)
|
|
goto out_unlock;
|
|
zbr->lnum = lnum;
|
|
zbr->offs = offs;
|
|
zbr->len = len;
|
|
found = 1;
|
|
} else if (is_hash_key(c, key)) {
|
|
found = resolve_collision_directly(c, key, &znode, &n,
|
|
old_lnum, old_offs);
|
|
dbg_tnc("rc returned %d, znode %p, n %d, LEB %d:%d",
|
|
found, znode, n, old_lnum, old_offs);
|
|
if (found < 0) {
|
|
err = found;
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (found) {
|
|
/* Ensure the znode is dirtied */
|
|
if (znode->cnext || !ubifs_zn_dirty(znode)) {
|
|
znode = dirty_cow_bottom_up(c, znode);
|
|
if (IS_ERR(znode)) {
|
|
err = PTR_ERR(znode);
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
zbr = &znode->zbranch[n];
|
|
lnc_free(zbr);
|
|
err = ubifs_add_dirt(c, zbr->lnum,
|
|
zbr->len);
|
|
if (err)
|
|
goto out_unlock;
|
|
zbr->lnum = lnum;
|
|
zbr->offs = offs;
|
|
zbr->len = len;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!found)
|
|
err = ubifs_add_dirt(c, lnum, len);
|
|
|
|
if (!err)
|
|
err = dbg_check_tnc(c, 0);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&c->tnc_mutex);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_add_nm - add a "hashed" node to TNC.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to add
|
|
* @lnum: LEB number of node
|
|
* @offs: node offset
|
|
* @len: node length
|
|
* @nm: node name
|
|
*
|
|
* This is the same as 'ubifs_tnc_add()' but it should be used with keys which
|
|
* may have collisions, like directory entry keys.
|
|
*/
|
|
int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key,
|
|
int lnum, int offs, int len, const struct qstr *nm)
|
|
{
|
|
int found, n, err = 0;
|
|
struct ubifs_znode *znode;
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
dbg_tnc("LEB %d:%d, name '%.*s', key %s", lnum, offs, nm->len, nm->name,
|
|
DBGKEY(key));
|
|
found = lookup_level0_dirty(c, key, &znode, &n);
|
|
if (found < 0) {
|
|
err = found;
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (found == 1) {
|
|
if (c->replaying)
|
|
found = fallible_resolve_collision(c, key, &znode, &n,
|
|
nm, 1);
|
|
else
|
|
found = resolve_collision(c, key, &znode, &n, nm);
|
|
dbg_tnc("rc returned %d, znode %p, n %d", found, znode, n);
|
|
if (found < 0) {
|
|
err = found;
|
|
goto out_unlock;
|
|
}
|
|
|
|
/* Ensure the znode is dirtied */
|
|
if (znode->cnext || !ubifs_zn_dirty(znode)) {
|
|
znode = dirty_cow_bottom_up(c, znode);
|
|
if (IS_ERR(znode)) {
|
|
err = PTR_ERR(znode);
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
|
|
if (found == 1) {
|
|
struct ubifs_zbranch *zbr = &znode->zbranch[n];
|
|
|
|
lnc_free(zbr);
|
|
err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
|
|
zbr->lnum = lnum;
|
|
zbr->offs = offs;
|
|
zbr->len = len;
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
|
|
if (!found) {
|
|
struct ubifs_zbranch zbr;
|
|
|
|
zbr.znode = NULL;
|
|
zbr.lnum = lnum;
|
|
zbr.offs = offs;
|
|
zbr.len = len;
|
|
key_copy(c, key, &zbr.key);
|
|
err = tnc_insert(c, znode, &zbr, n + 1);
|
|
if (err)
|
|
goto out_unlock;
|
|
if (c->replaying) {
|
|
/*
|
|
* We did not find it in the index so there may be a
|
|
* dangling branch still in the index. So we remove it
|
|
* by passing 'ubifs_tnc_remove_nm()' the same key but
|
|
* an unmatchable name.
|
|
*/
|
|
struct qstr noname = { .len = 0, .name = "" };
|
|
|
|
err = dbg_check_tnc(c, 0);
|
|
mutex_unlock(&c->tnc_mutex);
|
|
if (err)
|
|
return err;
|
|
return ubifs_tnc_remove_nm(c, key, &noname);
|
|
}
|
|
}
|
|
|
|
out_unlock:
|
|
if (!err)
|
|
err = dbg_check_tnc(c, 0);
|
|
mutex_unlock(&c->tnc_mutex);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* tnc_delete - delete a znode form TNC.
|
|
* @c: UBIFS file-system description object
|
|
* @znode: znode to delete from
|
|
* @n: zbranch slot number to delete
|
|
*
|
|
* This function deletes a leaf node from @n-th slot of @znode. Returns zero in
|
|
* case of success and a negative error code in case of failure.
|
|
*/
|
|
static int tnc_delete(struct ubifs_info *c, struct ubifs_znode *znode, int n)
|
|
{
|
|
struct ubifs_zbranch *zbr;
|
|
struct ubifs_znode *zp;
|
|
int i, err;
|
|
|
|
/* Delete without merge for now */
|
|
ubifs_assert(znode->level == 0);
|
|
ubifs_assert(n >= 0 && n < c->fanout);
|
|
dbg_tnc("deleting %s", DBGKEY(&znode->zbranch[n].key));
|
|
|
|
zbr = &znode->zbranch[n];
|
|
lnc_free(zbr);
|
|
|
|
err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
|
|
if (err) {
|
|
dbg_dump_znode(c, znode);
|
|
return err;
|
|
}
|
|
|
|
/* We do not "gap" zbranch slots */
|
|
for (i = n; i < znode->child_cnt - 1; i++)
|
|
znode->zbranch[i] = znode->zbranch[i + 1];
|
|
znode->child_cnt -= 1;
|
|
|
|
if (znode->child_cnt > 0)
|
|
return 0;
|
|
|
|
/*
|
|
* This was the last zbranch, we have to delete this znode from the
|
|
* parent.
|
|
*/
|
|
|
|
do {
|
|
ubifs_assert(!test_bit(OBSOLETE_ZNODE, &znode->flags));
|
|
ubifs_assert(ubifs_zn_dirty(znode));
|
|
|
|
zp = znode->parent;
|
|
n = znode->iip;
|
|
|
|
atomic_long_dec(&c->dirty_zn_cnt);
|
|
|
|
err = insert_old_idx_znode(c, znode);
|
|
if (err)
|
|
return err;
|
|
|
|
if (znode->cnext) {
|
|
__set_bit(OBSOLETE_ZNODE, &znode->flags);
|
|
atomic_long_inc(&c->clean_zn_cnt);
|
|
atomic_long_inc(&ubifs_clean_zn_cnt);
|
|
} else
|
|
kfree(znode);
|
|
znode = zp;
|
|
} while (znode->child_cnt == 1); /* while removing last child */
|
|
|
|
/* Remove from znode, entry n - 1 */
|
|
znode->child_cnt -= 1;
|
|
ubifs_assert(znode->level != 0);
|
|
for (i = n; i < znode->child_cnt; i++) {
|
|
znode->zbranch[i] = znode->zbranch[i + 1];
|
|
if (znode->zbranch[i].znode)
|
|
znode->zbranch[i].znode->iip = i;
|
|
}
|
|
|
|
/*
|
|
* If this is the root and it has only 1 child then
|
|
* collapse the tree.
|
|
*/
|
|
if (!znode->parent) {
|
|
while (znode->child_cnt == 1 && znode->level != 0) {
|
|
zp = znode;
|
|
zbr = &znode->zbranch[0];
|
|
znode = get_znode(c, znode, 0);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
znode = dirty_cow_znode(c, zbr);
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
znode->parent = NULL;
|
|
znode->iip = 0;
|
|
if (c->zroot.len) {
|
|
err = insert_old_idx(c, c->zroot.lnum,
|
|
c->zroot.offs);
|
|
if (err)
|
|
return err;
|
|
}
|
|
c->zroot.lnum = zbr->lnum;
|
|
c->zroot.offs = zbr->offs;
|
|
c->zroot.len = zbr->len;
|
|
c->zroot.znode = znode;
|
|
ubifs_assert(!test_bit(OBSOLETE_ZNODE,
|
|
&zp->flags));
|
|
ubifs_assert(test_bit(DIRTY_ZNODE, &zp->flags));
|
|
atomic_long_dec(&c->dirty_zn_cnt);
|
|
|
|
if (zp->cnext) {
|
|
__set_bit(OBSOLETE_ZNODE, &zp->flags);
|
|
atomic_long_inc(&c->clean_zn_cnt);
|
|
atomic_long_inc(&ubifs_clean_zn_cnt);
|
|
} else
|
|
kfree(zp);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_remove - remove an index entry of a node.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key of node
|
|
*
|
|
* Returns %0 on success or negative error code on failure.
|
|
*/
|
|
int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key)
|
|
{
|
|
int found, n, err = 0;
|
|
struct ubifs_znode *znode;
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
dbg_tnc("key %s", DBGKEY(key));
|
|
found = lookup_level0_dirty(c, key, &znode, &n);
|
|
if (found < 0) {
|
|
err = found;
|
|
goto out_unlock;
|
|
}
|
|
if (found == 1)
|
|
err = tnc_delete(c, znode, n);
|
|
if (!err)
|
|
err = dbg_check_tnc(c, 0);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&c->tnc_mutex);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_remove_nm - remove an index entry for a "hashed" node.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key of node
|
|
* @nm: directory entry name
|
|
*
|
|
* Returns %0 on success or negative error code on failure.
|
|
*/
|
|
int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key,
|
|
const struct qstr *nm)
|
|
{
|
|
int n, err;
|
|
struct ubifs_znode *znode;
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
dbg_tnc("%.*s, key %s", nm->len, nm->name, DBGKEY(key));
|
|
err = lookup_level0_dirty(c, key, &znode, &n);
|
|
if (err < 0)
|
|
goto out_unlock;
|
|
|
|
if (err) {
|
|
if (c->replaying)
|
|
err = fallible_resolve_collision(c, key, &znode, &n,
|
|
nm, 0);
|
|
else
|
|
err = resolve_collision(c, key, &znode, &n, nm);
|
|
dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n);
|
|
if (err < 0)
|
|
goto out_unlock;
|
|
if (err) {
|
|
/* Ensure the znode is dirtied */
|
|
if (znode->cnext || !ubifs_zn_dirty(znode)) {
|
|
znode = dirty_cow_bottom_up(c, znode);
|
|
if (IS_ERR(znode)) {
|
|
err = PTR_ERR(znode);
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
err = tnc_delete(c, znode, n);
|
|
}
|
|
}
|
|
|
|
out_unlock:
|
|
if (!err)
|
|
err = dbg_check_tnc(c, 0);
|
|
mutex_unlock(&c->tnc_mutex);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* key_in_range - determine if a key falls within a range of keys.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to check
|
|
* @from_key: lowest key in range
|
|
* @to_key: highest key in range
|
|
*
|
|
* This function returns %1 if the key is in range and %0 otherwise.
|
|
*/
|
|
static int key_in_range(struct ubifs_info *c, union ubifs_key *key,
|
|
union ubifs_key *from_key, union ubifs_key *to_key)
|
|
{
|
|
if (keys_cmp(c, key, from_key) < 0)
|
|
return 0;
|
|
if (keys_cmp(c, key, to_key) > 0)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_remove_range - remove index entries in range.
|
|
* @c: UBIFS file-system description object
|
|
* @from_key: lowest key to remove
|
|
* @to_key: highest key to remove
|
|
*
|
|
* This function removes index entries starting at @from_key and ending at
|
|
* @to_key. This function returns zero in case of success and a negative error
|
|
* code in case of failure.
|
|
*/
|
|
int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key,
|
|
union ubifs_key *to_key)
|
|
{
|
|
int i, n, k, err = 0;
|
|
struct ubifs_znode *znode;
|
|
union ubifs_key *key;
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
while (1) {
|
|
/* Find first level 0 znode that contains keys to remove */
|
|
err = ubifs_lookup_level0(c, from_key, &znode, &n);
|
|
if (err < 0)
|
|
goto out_unlock;
|
|
|
|
if (err)
|
|
key = from_key;
|
|
else {
|
|
err = tnc_next(c, &znode, &n);
|
|
if (err == -ENOENT) {
|
|
err = 0;
|
|
goto out_unlock;
|
|
}
|
|
if (err < 0)
|
|
goto out_unlock;
|
|
key = &znode->zbranch[n].key;
|
|
if (!key_in_range(c, key, from_key, to_key)) {
|
|
err = 0;
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
|
|
/* Ensure the znode is dirtied */
|
|
if (znode->cnext || !ubifs_zn_dirty(znode)) {
|
|
znode = dirty_cow_bottom_up(c, znode);
|
|
if (IS_ERR(znode)) {
|
|
err = PTR_ERR(znode);
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
|
|
/* Remove all keys in range except the first */
|
|
for (i = n + 1, k = 0; i < znode->child_cnt; i++, k++) {
|
|
key = &znode->zbranch[i].key;
|
|
if (!key_in_range(c, key, from_key, to_key))
|
|
break;
|
|
lnc_free(&znode->zbranch[i]);
|
|
err = ubifs_add_dirt(c, znode->zbranch[i].lnum,
|
|
znode->zbranch[i].len);
|
|
if (err) {
|
|
dbg_dump_znode(c, znode);
|
|
goto out_unlock;
|
|
}
|
|
dbg_tnc("removing %s", DBGKEY(key));
|
|
}
|
|
if (k) {
|
|
for (i = n + 1 + k; i < znode->child_cnt; i++)
|
|
znode->zbranch[i - k] = znode->zbranch[i];
|
|
znode->child_cnt -= k;
|
|
}
|
|
|
|
/* Now delete the first */
|
|
err = tnc_delete(c, znode, n);
|
|
if (err)
|
|
goto out_unlock;
|
|
}
|
|
|
|
out_unlock:
|
|
if (!err)
|
|
err = dbg_check_tnc(c, 0);
|
|
mutex_unlock(&c->tnc_mutex);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_remove_ino - remove an inode from TNC.
|
|
* @c: UBIFS file-system description object
|
|
* @inum: inode number to remove
|
|
*
|
|
* This function remove inode @inum and all the extended attributes associated
|
|
* with the anode from TNC and returns zero in case of success or a negative
|
|
* error code in case of failure.
|
|
*/
|
|
int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum)
|
|
{
|
|
union ubifs_key key1, key2;
|
|
struct ubifs_dent_node *xent, *pxent = NULL;
|
|
struct qstr nm = { .name = NULL };
|
|
|
|
dbg_tnc("ino %lu", (unsigned long)inum);
|
|
|
|
/*
|
|
* Walk all extended attribute entries and remove them together with
|
|
* corresponding extended attribute inodes.
|
|
*/
|
|
lowest_xent_key(c, &key1, inum);
|
|
while (1) {
|
|
ino_t xattr_inum;
|
|
int err;
|
|
|
|
xent = ubifs_tnc_next_ent(c, &key1, &nm);
|
|
if (IS_ERR(xent)) {
|
|
err = PTR_ERR(xent);
|
|
if (err == -ENOENT)
|
|
break;
|
|
return err;
|
|
}
|
|
|
|
xattr_inum = le64_to_cpu(xent->inum);
|
|
dbg_tnc("xent '%s', ino %lu", xent->name,
|
|
(unsigned long)xattr_inum);
|
|
|
|
nm.name = xent->name;
|
|
nm.len = le16_to_cpu(xent->nlen);
|
|
err = ubifs_tnc_remove_nm(c, &key1, &nm);
|
|
if (err) {
|
|
kfree(xent);
|
|
return err;
|
|
}
|
|
|
|
lowest_ino_key(c, &key1, xattr_inum);
|
|
highest_ino_key(c, &key2, xattr_inum);
|
|
err = ubifs_tnc_remove_range(c, &key1, &key2);
|
|
if (err) {
|
|
kfree(xent);
|
|
return err;
|
|
}
|
|
|
|
kfree(pxent);
|
|
pxent = xent;
|
|
key_read(c, &xent->key, &key1);
|
|
}
|
|
|
|
kfree(pxent);
|
|
lowest_ino_key(c, &key1, inum);
|
|
highest_ino_key(c, &key2, inum);
|
|
|
|
return ubifs_tnc_remove_range(c, &key1, &key2);
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_next_ent - walk directory or extended attribute entries.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key of last entry
|
|
* @nm: name of last entry found or %NULL
|
|
*
|
|
* This function finds and reads the next directory or extended attribute entry
|
|
* after the given key (@key) if there is one. @nm is used to resolve
|
|
* collisions.
|
|
*
|
|
* If the name of the current entry is not known and only the key is known,
|
|
* @nm->name has to be %NULL. In this case the semantics of this function is a
|
|
* little bit different and it returns the entry corresponding to this key, not
|
|
* the next one. If the key was not found, the closest "right" entry is
|
|
* returned.
|
|
*
|
|
* If the fist entry has to be found, @key has to contain the lowest possible
|
|
* key value for this inode and @name has to be %NULL.
|
|
*
|
|
* This function returns the found directory or extended attribute entry node
|
|
* in case of success, %-ENOENT is returned if no entry was found, and a
|
|
* negative error code is returned in case of failure.
|
|
*/
|
|
struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c,
|
|
union ubifs_key *key,
|
|
const struct qstr *nm)
|
|
{
|
|
int n, err, type = key_type(c, key);
|
|
struct ubifs_znode *znode;
|
|
struct ubifs_dent_node *dent;
|
|
struct ubifs_zbranch *zbr;
|
|
union ubifs_key *dkey;
|
|
|
|
dbg_tnc("%s %s", nm->name ? (char *)nm->name : "(lowest)", DBGKEY(key));
|
|
ubifs_assert(is_hash_key(c, key));
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
err = ubifs_lookup_level0(c, key, &znode, &n);
|
|
if (unlikely(err < 0))
|
|
goto out_unlock;
|
|
|
|
if (nm->name) {
|
|
if (err) {
|
|
/* Handle collisions */
|
|
err = resolve_collision(c, key, &znode, &n, nm);
|
|
dbg_tnc("rc returned %d, znode %p, n %d",
|
|
err, znode, n);
|
|
if (unlikely(err < 0))
|
|
goto out_unlock;
|
|
}
|
|
|
|
/* Now find next entry */
|
|
err = tnc_next(c, &znode, &n);
|
|
if (unlikely(err))
|
|
goto out_unlock;
|
|
} else {
|
|
/*
|
|
* The full name of the entry was not given, in which case the
|
|
* behavior of this function is a little different and it
|
|
* returns current entry, not the next one.
|
|
*/
|
|
if (!err) {
|
|
/*
|
|
* However, the given key does not exist in the TNC
|
|
* tree and @znode/@n variables contain the closest
|
|
* "preceding" element. Switch to the next one.
|
|
*/
|
|
err = tnc_next(c, &znode, &n);
|
|
if (err)
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
|
|
zbr = &znode->zbranch[n];
|
|
dent = kmalloc(zbr->len, GFP_NOFS);
|
|
if (unlikely(!dent)) {
|
|
err = -ENOMEM;
|
|
goto out_unlock;
|
|
}
|
|
|
|
/*
|
|
* The above 'tnc_next()' call could lead us to the next inode, check
|
|
* this.
|
|
*/
|
|
dkey = &zbr->key;
|
|
if (key_inum(c, dkey) != key_inum(c, key) ||
|
|
key_type(c, dkey) != type) {
|
|
err = -ENOENT;
|
|
goto out_free;
|
|
}
|
|
|
|
err = tnc_read_node_nm(c, zbr, dent);
|
|
if (unlikely(err))
|
|
goto out_free;
|
|
|
|
mutex_unlock(&c->tnc_mutex);
|
|
return dent;
|
|
|
|
out_free:
|
|
kfree(dent);
|
|
out_unlock:
|
|
mutex_unlock(&c->tnc_mutex);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
/**
|
|
* tnc_destroy_cnext - destroy left-over obsolete znodes from a failed commit.
|
|
* @c: UBIFS file-system description object
|
|
*
|
|
* Destroy left-over obsolete znodes from a failed commit.
|
|
*/
|
|
static void tnc_destroy_cnext(struct ubifs_info *c)
|
|
{
|
|
struct ubifs_znode *cnext;
|
|
|
|
if (!c->cnext)
|
|
return;
|
|
ubifs_assert(c->cmt_state == COMMIT_BROKEN);
|
|
cnext = c->cnext;
|
|
do {
|
|
struct ubifs_znode *znode = cnext;
|
|
|
|
cnext = cnext->cnext;
|
|
if (test_bit(OBSOLETE_ZNODE, &znode->flags))
|
|
kfree(znode);
|
|
} while (cnext && cnext != c->cnext);
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_close - close TNC subsystem and free all related resources.
|
|
* @c: UBIFS file-system description object
|
|
*/
|
|
void ubifs_tnc_close(struct ubifs_info *c)
|
|
{
|
|
long clean_freed;
|
|
|
|
tnc_destroy_cnext(c);
|
|
if (c->zroot.znode) {
|
|
clean_freed = ubifs_destroy_tnc_subtree(c->zroot.znode);
|
|
atomic_long_sub(clean_freed, &ubifs_clean_zn_cnt);
|
|
}
|
|
kfree(c->gap_lebs);
|
|
kfree(c->ilebs);
|
|
destroy_old_idx(c);
|
|
}
|
|
|
|
/**
|
|
* left_znode - get the znode to the left.
|
|
* @c: UBIFS file-system description object
|
|
* @znode: znode
|
|
*
|
|
* This function returns a pointer to the znode to the left of @znode or NULL if
|
|
* there is not one. A negative error code is returned on failure.
|
|
*/
|
|
static struct ubifs_znode *left_znode(struct ubifs_info *c,
|
|
struct ubifs_znode *znode)
|
|
{
|
|
int level = znode->level;
|
|
|
|
while (1) {
|
|
int n = znode->iip - 1;
|
|
|
|
/* Go up until we can go left */
|
|
znode = znode->parent;
|
|
if (!znode)
|
|
return NULL;
|
|
if (n >= 0) {
|
|
/* Now go down the rightmost branch to 'level' */
|
|
znode = get_znode(c, znode, n);
|
|
if (IS_ERR(znode))
|
|
return znode;
|
|
while (znode->level != level) {
|
|
n = znode->child_cnt - 1;
|
|
znode = get_znode(c, znode, n);
|
|
if (IS_ERR(znode))
|
|
return znode;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
return znode;
|
|
}
|
|
|
|
/**
|
|
* right_znode - get the znode to the right.
|
|
* @c: UBIFS file-system description object
|
|
* @znode: znode
|
|
*
|
|
* This function returns a pointer to the znode to the right of @znode or NULL
|
|
* if there is not one. A negative error code is returned on failure.
|
|
*/
|
|
static struct ubifs_znode *right_znode(struct ubifs_info *c,
|
|
struct ubifs_znode *znode)
|
|
{
|
|
int level = znode->level;
|
|
|
|
while (1) {
|
|
int n = znode->iip + 1;
|
|
|
|
/* Go up until we can go right */
|
|
znode = znode->parent;
|
|
if (!znode)
|
|
return NULL;
|
|
if (n < znode->child_cnt) {
|
|
/* Now go down the leftmost branch to 'level' */
|
|
znode = get_znode(c, znode, n);
|
|
if (IS_ERR(znode))
|
|
return znode;
|
|
while (znode->level != level) {
|
|
znode = get_znode(c, znode, 0);
|
|
if (IS_ERR(znode))
|
|
return znode;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
return znode;
|
|
}
|
|
|
|
/**
|
|
* lookup_znode - find a particular indexing node from TNC.
|
|
* @c: UBIFS file-system description object
|
|
* @key: index node key to lookup
|
|
* @level: index node level
|
|
* @lnum: index node LEB number
|
|
* @offs: index node offset
|
|
*
|
|
* This function searches an indexing node by its first key @key and its
|
|
* address @lnum:@offs. It looks up the indexing tree by pulling all indexing
|
|
* nodes it traverses to TNC. This function is called fro indexing nodes which
|
|
* were found on the media by scanning, for example when garbage-collecting or
|
|
* when doing in-the-gaps commit. This means that the indexing node which is
|
|
* looked for does not have to have exactly the same leftmost key @key, because
|
|
* the leftmost key may have been changed, in which case TNC will contain a
|
|
* dirty znode which still refers the same @lnum:@offs. This function is clever
|
|
* enough to recognize such indexing nodes.
|
|
*
|
|
* Note, if a znode was deleted or changed too much, then this function will
|
|
* not find it. For situations like this UBIFS has the old index RB-tree
|
|
* (indexed by @lnum:@offs).
|
|
*
|
|
* This function returns a pointer to the znode found or %NULL if it is not
|
|
* found. A negative error code is returned on failure.
|
|
*/
|
|
static struct ubifs_znode *lookup_znode(struct ubifs_info *c,
|
|
union ubifs_key *key, int level,
|
|
int lnum, int offs)
|
|
{
|
|
struct ubifs_znode *znode, *zn;
|
|
int n, nn;
|
|
|
|
/*
|
|
* The arguments have probably been read off flash, so don't assume
|
|
* they are valid.
|
|
*/
|
|
if (level < 0)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
/* Get the root znode */
|
|
znode = c->zroot.znode;
|
|
if (!znode) {
|
|
znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
|
|
if (IS_ERR(znode))
|
|
return znode;
|
|
}
|
|
/* Check if it is the one we are looking for */
|
|
if (c->zroot.lnum == lnum && c->zroot.offs == offs)
|
|
return znode;
|
|
/* Descend to the parent level i.e. (level + 1) */
|
|
if (level >= znode->level)
|
|
return NULL;
|
|
while (1) {
|
|
ubifs_search_zbranch(c, znode, key, &n);
|
|
if (n < 0) {
|
|
/*
|
|
* We reached a znode where the leftmost key is greater
|
|
* than the key we are searching for. This is the same
|
|
* situation as the one described in a huge comment at
|
|
* the end of the 'ubifs_lookup_level0()' function. And
|
|
* for exactly the same reasons we have to try to look
|
|
* left before giving up.
|
|
*/
|
|
znode = left_znode(c, znode);
|
|
if (!znode)
|
|
return NULL;
|
|
if (IS_ERR(znode))
|
|
return znode;
|
|
ubifs_search_zbranch(c, znode, key, &n);
|
|
ubifs_assert(n >= 0);
|
|
}
|
|
if (znode->level == level + 1)
|
|
break;
|
|
znode = get_znode(c, znode, n);
|
|
if (IS_ERR(znode))
|
|
return znode;
|
|
}
|
|
/* Check if the child is the one we are looking for */
|
|
if (znode->zbranch[n].lnum == lnum && znode->zbranch[n].offs == offs)
|
|
return get_znode(c, znode, n);
|
|
/* If the key is unique, there is nowhere else to look */
|
|
if (!is_hash_key(c, key))
|
|
return NULL;
|
|
/*
|
|
* The key is not unique and so may be also in the znodes to either
|
|
* side.
|
|
*/
|
|
zn = znode;
|
|
nn = n;
|
|
/* Look left */
|
|
while (1) {
|
|
/* Move one branch to the left */
|
|
if (n)
|
|
n -= 1;
|
|
else {
|
|
znode = left_znode(c, znode);
|
|
if (!znode)
|
|
break;
|
|
if (IS_ERR(znode))
|
|
return znode;
|
|
n = znode->child_cnt - 1;
|
|
}
|
|
/* Check it */
|
|
if (znode->zbranch[n].lnum == lnum &&
|
|
znode->zbranch[n].offs == offs)
|
|
return get_znode(c, znode, n);
|
|
/* Stop if the key is less than the one we are looking for */
|
|
if (keys_cmp(c, &znode->zbranch[n].key, key) < 0)
|
|
break;
|
|
}
|
|
/* Back to the middle */
|
|
znode = zn;
|
|
n = nn;
|
|
/* Look right */
|
|
while (1) {
|
|
/* Move one branch to the right */
|
|
if (++n >= znode->child_cnt) {
|
|
znode = right_znode(c, znode);
|
|
if (!znode)
|
|
break;
|
|
if (IS_ERR(znode))
|
|
return znode;
|
|
n = 0;
|
|
}
|
|
/* Check it */
|
|
if (znode->zbranch[n].lnum == lnum &&
|
|
znode->zbranch[n].offs == offs)
|
|
return get_znode(c, znode, n);
|
|
/* Stop if the key is greater than the one we are looking for */
|
|
if (keys_cmp(c, &znode->zbranch[n].key, key) > 0)
|
|
break;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* is_idx_node_in_tnc - determine if an index node is in the TNC.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key of index node
|
|
* @level: index node level
|
|
* @lnum: LEB number of index node
|
|
* @offs: offset of index node
|
|
*
|
|
* This function returns %0 if the index node is not referred to in the TNC, %1
|
|
* if the index node is referred to in the TNC and the corresponding znode is
|
|
* dirty, %2 if an index node is referred to in the TNC and the corresponding
|
|
* znode is clean, and a negative error code in case of failure.
|
|
*
|
|
* Note, the @key argument has to be the key of the first child. Also note,
|
|
* this function relies on the fact that 0:0 is never a valid LEB number and
|
|
* offset for a main-area node.
|
|
*/
|
|
int is_idx_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, int level,
|
|
int lnum, int offs)
|
|
{
|
|
struct ubifs_znode *znode;
|
|
|
|
znode = lookup_znode(c, key, level, lnum, offs);
|
|
if (!znode)
|
|
return 0;
|
|
if (IS_ERR(znode))
|
|
return PTR_ERR(znode);
|
|
|
|
return ubifs_zn_dirty(znode) ? 1 : 2;
|
|
}
|
|
|
|
/**
|
|
* is_leaf_node_in_tnc - determine if a non-indexing not is in the TNC.
|
|
* @c: UBIFS file-system description object
|
|
* @key: node key
|
|
* @lnum: node LEB number
|
|
* @offs: node offset
|
|
*
|
|
* This function returns %1 if the node is referred to in the TNC, %0 if it is
|
|
* not, and a negative error code in case of failure.
|
|
*
|
|
* Note, this function relies on the fact that 0:0 is never a valid LEB number
|
|
* and offset for a main-area node.
|
|
*/
|
|
static int is_leaf_node_in_tnc(struct ubifs_info *c, union ubifs_key *key,
|
|
int lnum, int offs)
|
|
{
|
|
struct ubifs_zbranch *zbr;
|
|
struct ubifs_znode *znode, *zn;
|
|
int n, found, err, nn;
|
|
const int unique = !is_hash_key(c, key);
|
|
|
|
found = ubifs_lookup_level0(c, key, &znode, &n);
|
|
if (found < 0)
|
|
return found; /* Error code */
|
|
if (!found)
|
|
return 0;
|
|
zbr = &znode->zbranch[n];
|
|
if (lnum == zbr->lnum && offs == zbr->offs)
|
|
return 1; /* Found it */
|
|
if (unique)
|
|
return 0;
|
|
/*
|
|
* Because the key is not unique, we have to look left
|
|
* and right as well
|
|
*/
|
|
zn = znode;
|
|
nn = n;
|
|
/* Look left */
|
|
while (1) {
|
|
err = tnc_prev(c, &znode, &n);
|
|
if (err == -ENOENT)
|
|
break;
|
|
if (err)
|
|
return err;
|
|
if (keys_cmp(c, key, &znode->zbranch[n].key))
|
|
break;
|
|
zbr = &znode->zbranch[n];
|
|
if (lnum == zbr->lnum && offs == zbr->offs)
|
|
return 1; /* Found it */
|
|
}
|
|
/* Look right */
|
|
znode = zn;
|
|
n = nn;
|
|
while (1) {
|
|
err = tnc_next(c, &znode, &n);
|
|
if (err) {
|
|
if (err == -ENOENT)
|
|
return 0;
|
|
return err;
|
|
}
|
|
if (keys_cmp(c, key, &znode->zbranch[n].key))
|
|
break;
|
|
zbr = &znode->zbranch[n];
|
|
if (lnum == zbr->lnum && offs == zbr->offs)
|
|
return 1; /* Found it */
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ubifs_tnc_has_node - determine whether a node is in the TNC.
|
|
* @c: UBIFS file-system description object
|
|
* @key: node key
|
|
* @level: index node level (if it is an index node)
|
|
* @lnum: node LEB number
|
|
* @offs: node offset
|
|
* @is_idx: non-zero if the node is an index node
|
|
*
|
|
* This function returns %1 if the node is in the TNC, %0 if it is not, and a
|
|
* negative error code in case of failure. For index nodes, @key has to be the
|
|
* key of the first child. An index node is considered to be in the TNC only if
|
|
* the corresponding znode is clean or has not been loaded.
|
|
*/
|
|
int ubifs_tnc_has_node(struct ubifs_info *c, union ubifs_key *key, int level,
|
|
int lnum, int offs, int is_idx)
|
|
{
|
|
int err;
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
if (is_idx) {
|
|
err = is_idx_node_in_tnc(c, key, level, lnum, offs);
|
|
if (err < 0)
|
|
goto out_unlock;
|
|
if (err == 1)
|
|
/* The index node was found but it was dirty */
|
|
err = 0;
|
|
else if (err == 2)
|
|
/* The index node was found and it was clean */
|
|
err = 1;
|
|
else
|
|
BUG_ON(err != 0);
|
|
} else
|
|
err = is_leaf_node_in_tnc(c, key, lnum, offs);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&c->tnc_mutex);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubifs_dirty_idx_node - dirty an index node.
|
|
* @c: UBIFS file-system description object
|
|
* @key: index node key
|
|
* @level: index node level
|
|
* @lnum: index node LEB number
|
|
* @offs: index node offset
|
|
*
|
|
* This function loads and dirties an index node so that it can be garbage
|
|
* collected. The @key argument has to be the key of the first child. This
|
|
* function relies on the fact that 0:0 is never a valid LEB number and offset
|
|
* for a main-area node. Returns %0 on success and a negative error code on
|
|
* failure.
|
|
*/
|
|
int ubifs_dirty_idx_node(struct ubifs_info *c, union ubifs_key *key, int level,
|
|
int lnum, int offs)
|
|
{
|
|
struct ubifs_znode *znode;
|
|
int err = 0;
|
|
|
|
mutex_lock(&c->tnc_mutex);
|
|
znode = lookup_znode(c, key, level, lnum, offs);
|
|
if (!znode)
|
|
goto out_unlock;
|
|
if (IS_ERR(znode)) {
|
|
err = PTR_ERR(znode);
|
|
goto out_unlock;
|
|
}
|
|
znode = dirty_cow_bottom_up(c, znode);
|
|
if (IS_ERR(znode)) {
|
|
err = PTR_ERR(znode);
|
|
goto out_unlock;
|
|
}
|
|
|
|
out_unlock:
|
|
mutex_unlock(&c->tnc_mutex);
|
|
return err;
|
|
}
|