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License notice (GPLv2+); comments about the bad blocks

master
Vitaliy Filippov 2014-01-07 13:07:24 +00:00
parent 8cc74f4f27
commit 553e1273ea
1 changed files with 23 additions and 4 deletions
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realloc-inodes.c
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@ -2,6 +2,25 @@
* A tool for ext2/ext3/ext4 filesystems that allows to change inode count
* without recreating it.
*
* Copyright (c) Vitaliy Filippov <vitalif@mail.ru> 2014
* License: GNU GPLv2 or later
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* TODO bigalloc compatibility
* TODO write some tests: for inode moving (image with many files),
* for block moving, including extent blocks (one sparse file with many extents),
@ -15,13 +34,13 @@
* 2.1) Create a map of blocks that we want to free
* 2.2) Iterate through all inodes and move remembered blocks.
* It involves overwriting the whole file extent tree or block mapping...
* If some of these blocks are in the bad block inode, we should either
* abort the reallocation process, or move inode tables to another location
* in a block group, possibly first defragmenting it... :-(
* If some of these blocks are in the bad block inode, abort the reallocation process.
* We could possibly try to move inode tables to another location in a block group
* in that case; but it may be needed to defragment it first... :-(
* 3) Change all inode numbers in directory entries according to mappings from (1.2),
* and then using a formula: new_num = 1 + ((old_num-1)/old_i_per_g)*new_i_per_g + ((old_num-1) % old_i_per_g)
* 4) Move parts of inode tables so they are consecutive again if flex_bg feature is active
* 5) Mark/unmark extra blocks for inode tables
* 5) Mark/unmark extra blocks used for inode tables
* 6) Change block group descriptors: bg_inode_table, bg_free_inodes_count,
* bg_free_blocks_count, bg_inode_bitmap_csum, bg_itable_unused
* 7) Change superblock: s_inodes_count, s_free_blocks_count,