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https://github.com/brain-hackers/u-boot-brain
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![Stefan Roese](/assets/img/avatar_default.png)
The U-Boot UBIFS implementation is largely a direct copy from the current Linux version (2.6.29-rc6). As already done in the UBI version we have an "abstraction layer" to redefine or remove some OS calls (e.g. mutex_lock() ...). This makes it possible to use the original Linux code with very little changes. And by this we can better update to later Linux versions. I removed some of the Linux features that are not used in the U-Boot version (e.g. garbage-collection, write support). Signed-off-by: Stefan Roese <sr@denx.de> CC: Artem Bityutskiy <dedekind@infradead.org> CC: Adrian Hunter <ext-Adrian.Hunter@nokia.com>
317 lines
9.8 KiB
C
317 lines
9.8 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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* Author: Adrian Hunter
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*/
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#include "ubifs.h"
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/*
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* An orphan is an inode number whose inode node has been committed to the index
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* with a link count of zero. That happens when an open file is deleted
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* (unlinked) and then a commit is run. In the normal course of events the inode
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* would be deleted when the file is closed. However in the case of an unclean
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* unmount, orphans need to be accounted for. After an unclean unmount, the
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* orphans' inodes must be deleted which means either scanning the entire index
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* looking for them, or keeping a list on flash somewhere. This unit implements
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* the latter approach.
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*
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* The orphan area is a fixed number of LEBs situated between the LPT area and
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* the main area. The number of orphan area LEBs is specified when the file
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* system is created. The minimum number is 1. The size of the orphan area
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* should be so that it can hold the maximum number of orphans that are expected
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* to ever exist at one time.
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*
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* The number of orphans that can fit in a LEB is:
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*
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* (c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64)
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*
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* For example: a 15872 byte LEB can fit 1980 orphans so 1 LEB may be enough.
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*
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* Orphans are accumulated in a rb-tree. When an inode's link count drops to
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* zero, the inode number is added to the rb-tree. It is removed from the tree
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* when the inode is deleted. Any new orphans that are in the orphan tree when
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* the commit is run, are written to the orphan area in 1 or more orphan nodes.
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* If the orphan area is full, it is consolidated to make space. There is
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* always enough space because validation prevents the user from creating more
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* than the maximum number of orphans allowed.
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*/
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/**
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* tot_avail_orphs - calculate total space.
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* @c: UBIFS file-system description object
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*
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* This function returns the number of orphans that can be written in half
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* the total space. That leaves half the space for adding new orphans.
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*/
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static int tot_avail_orphs(struct ubifs_info *c)
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{
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int avail_lebs, avail;
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avail_lebs = c->orph_lebs;
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avail = avail_lebs *
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((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64));
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return avail / 2;
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}
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/**
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* ubifs_clear_orphans - erase all LEBs used for orphans.
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* @c: UBIFS file-system description object
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*
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* If recovery is not required, then the orphans from the previous session
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* are not needed. This function locates the LEBs used to record
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* orphans, and un-maps them.
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*/
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int ubifs_clear_orphans(struct ubifs_info *c)
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{
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int lnum, err;
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for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
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err = ubifs_leb_unmap(c, lnum);
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if (err)
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return err;
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}
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c->ohead_lnum = c->orph_first;
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c->ohead_offs = 0;
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return 0;
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}
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/**
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* insert_dead_orphan - insert an orphan.
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* @c: UBIFS file-system description object
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* @inum: orphan inode number
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*
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* This function is a helper to the 'do_kill_orphans()' function. The orphan
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* must be kept until the next commit, so it is added to the rb-tree and the
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* deletion list.
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*/
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static int insert_dead_orphan(struct ubifs_info *c, ino_t inum)
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{
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struct ubifs_orphan *orphan, *o;
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struct rb_node **p, *parent = NULL;
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orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_KERNEL);
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if (!orphan)
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return -ENOMEM;
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orphan->inum = inum;
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p = &c->orph_tree.rb_node;
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while (*p) {
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parent = *p;
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o = rb_entry(parent, struct ubifs_orphan, rb);
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if (inum < o->inum)
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p = &(*p)->rb_left;
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else if (inum > o->inum)
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p = &(*p)->rb_right;
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else {
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/* Already added - no problem */
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kfree(orphan);
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return 0;
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}
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}
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c->tot_orphans += 1;
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rb_link_node(&orphan->rb, parent, p);
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rb_insert_color(&orphan->rb, &c->orph_tree);
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list_add_tail(&orphan->list, &c->orph_list);
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orphan->dnext = c->orph_dnext;
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c->orph_dnext = orphan;
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dbg_mnt("ino %lu, new %d, tot %d", (unsigned long)inum,
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c->new_orphans, c->tot_orphans);
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return 0;
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}
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/**
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* do_kill_orphans - remove orphan inodes from the index.
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* @c: UBIFS file-system description object
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* @sleb: scanned LEB
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* @last_cmt_no: cmt_no of last orphan node read is passed and returned here
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* @outofdate: whether the LEB is out of date is returned here
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* @last_flagged: whether the end orphan node is encountered
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*
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* This function is a helper to the 'kill_orphans()' function. It goes through
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* every orphan node in a LEB and for every inode number recorded, removes
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* all keys for that inode from the TNC.
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*/
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static int do_kill_orphans(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
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unsigned long long *last_cmt_no, int *outofdate,
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int *last_flagged)
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{
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struct ubifs_scan_node *snod;
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struct ubifs_orph_node *orph;
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unsigned long long cmt_no;
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ino_t inum;
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int i, n, err, first = 1;
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list_for_each_entry(snod, &sleb->nodes, list) {
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if (snod->type != UBIFS_ORPH_NODE) {
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ubifs_err("invalid node type %d in orphan area at "
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"%d:%d", snod->type, sleb->lnum, snod->offs);
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dbg_dump_node(c, snod->node);
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return -EINVAL;
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}
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orph = snod->node;
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/* Check commit number */
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cmt_no = le64_to_cpu(orph->cmt_no) & LLONG_MAX;
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/*
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* The commit number on the master node may be less, because
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* of a failed commit. If there are several failed commits in a
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* row, the commit number written on orphan nodes will continue
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* to increase (because the commit number is adjusted here) even
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* though the commit number on the master node stays the same
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* because the master node has not been re-written.
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*/
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if (cmt_no > c->cmt_no)
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c->cmt_no = cmt_no;
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if (cmt_no < *last_cmt_no && *last_flagged) {
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/*
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* The last orphan node had a higher commit number and
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* was flagged as the last written for that commit
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* number. That makes this orphan node, out of date.
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*/
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if (!first) {
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ubifs_err("out of order commit number %llu in "
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"orphan node at %d:%d",
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cmt_no, sleb->lnum, snod->offs);
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dbg_dump_node(c, snod->node);
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return -EINVAL;
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}
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dbg_rcvry("out of date LEB %d", sleb->lnum);
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*outofdate = 1;
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return 0;
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}
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if (first)
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first = 0;
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n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
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for (i = 0; i < n; i++) {
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inum = le64_to_cpu(orph->inos[i]);
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dbg_rcvry("deleting orphaned inode %lu",
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(unsigned long)inum);
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err = ubifs_tnc_remove_ino(c, inum);
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if (err)
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return err;
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err = insert_dead_orphan(c, inum);
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if (err)
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return err;
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}
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*last_cmt_no = cmt_no;
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if (le64_to_cpu(orph->cmt_no) & (1ULL << 63)) {
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dbg_rcvry("last orph node for commit %llu at %d:%d",
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cmt_no, sleb->lnum, snod->offs);
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*last_flagged = 1;
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} else
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*last_flagged = 0;
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}
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return 0;
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}
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/**
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* kill_orphans - remove all orphan inodes from the index.
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* @c: UBIFS file-system description object
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*
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* If recovery is required, then orphan inodes recorded during the previous
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* session (which ended with an unclean unmount) must be deleted from the index.
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* This is done by updating the TNC, but since the index is not updated until
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* the next commit, the LEBs where the orphan information is recorded are not
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* erased until the next commit.
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*/
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static int kill_orphans(struct ubifs_info *c)
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{
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unsigned long long last_cmt_no = 0;
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int lnum, err = 0, outofdate = 0, last_flagged = 0;
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c->ohead_lnum = c->orph_first;
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c->ohead_offs = 0;
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/* Check no-orphans flag and skip this if no orphans */
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if (c->no_orphs) {
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dbg_rcvry("no orphans");
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return 0;
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}
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/*
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* Orph nodes always start at c->orph_first and are written to each
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* successive LEB in turn. Generally unused LEBs will have been unmapped
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* but may contain out of date orphan nodes if the unmap didn't go
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* through. In addition, the last orphan node written for each commit is
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* marked (top bit of orph->cmt_no is set to 1). It is possible that
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* there are orphan nodes from the next commit (i.e. the commit did not
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* complete successfully). In that case, no orphans will have been lost
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* due to the way that orphans are written, and any orphans added will
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* be valid orphans anyway and so can be deleted.
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*/
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for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
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struct ubifs_scan_leb *sleb;
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dbg_rcvry("LEB %d", lnum);
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sleb = ubifs_scan(c, lnum, 0, c->sbuf);
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if (IS_ERR(sleb)) {
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sleb = ubifs_recover_leb(c, lnum, 0, c->sbuf, 0);
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if (IS_ERR(sleb)) {
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err = PTR_ERR(sleb);
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break;
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}
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}
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err = do_kill_orphans(c, sleb, &last_cmt_no, &outofdate,
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&last_flagged);
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if (err || outofdate) {
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ubifs_scan_destroy(sleb);
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break;
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}
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if (sleb->endpt) {
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c->ohead_lnum = lnum;
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c->ohead_offs = sleb->endpt;
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}
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ubifs_scan_destroy(sleb);
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}
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return err;
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}
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/**
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* ubifs_mount_orphans - delete orphan inodes and erase LEBs that recorded them.
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* @c: UBIFS file-system description object
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* @unclean: indicates recovery from unclean unmount
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* @read_only: indicates read only mount
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*
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* This function is called when mounting to erase orphans from the previous
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* session. If UBIFS was not unmounted cleanly, then the inodes recorded as
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* orphans are deleted.
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*/
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int ubifs_mount_orphans(struct ubifs_info *c, int unclean, int read_only)
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{
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int err = 0;
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c->max_orphans = tot_avail_orphs(c);
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if (!read_only) {
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c->orph_buf = vmalloc(c->leb_size);
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if (!c->orph_buf)
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return -ENOMEM;
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}
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if (unclean)
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err = kill_orphans(c);
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else if (!read_only)
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err = ubifs_clear_orphans(c);
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return err;
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}
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