279 lines
		
	
	
		
			8.0 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			279 lines
		
	
	
		
			8.0 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * alloc_tables.c --- Allocate tables for a newly initialized
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|  * filesystem.  Used by mke2fs when initializing a filesystem
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|  *
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|  * Copyright (C) 1996 Theodore Ts'o.
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|  *
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|  * %Begin-Header%
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|  * This file may be redistributed under the terms of the GNU Library
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|  * General Public License, version 2.
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|  * %End-Header%
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|  */
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| 
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| #include "config.h"
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| #include <stdio.h>
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| #include <string.h>
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| #if HAVE_UNISTD_H
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| #include <unistd.h>
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| #endif
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| #include <fcntl.h>
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| #include <time.h>
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| #if HAVE_SYS_STAT_H
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| #include <sys/stat.h>
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| #endif
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| #if HAVE_SYS_TYPES_H
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| #include <sys/types.h>
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| #endif
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| 
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| #include "ext2_fs.h"
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| #include "ext2fs.h"
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| #include "ext2fsP.h"
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| 
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| /*
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|  * This routine searches for free blocks that can allocate a full
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|  * group of bitmaps or inode tables for a flexbg group.  Returns the
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|  * block number with a correct offset were the bitmaps and inode
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|  * tables can be allocated continuously and in order.
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|  */
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| static blk64_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk64_t start_blk,
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| 			     ext2fs_block_bitmap bmap, int rem_grp,
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| 			     int elem_size)
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| {
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| 	int		flexbg, flexbg_size, size;
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| 	blk64_t		last_blk, first_free = 0;
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| 	dgrp_t	       	last_grp;
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| 
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| 	flexbg_size = 1 << fs->super->s_log_groups_per_flex;
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| 	flexbg = group / flexbg_size;
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| 	size = rem_grp * elem_size;
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| 
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| 	if (size > (int) (fs->super->s_blocks_per_group / 4))
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| 		size = (int) fs->super->s_blocks_per_group / 4;
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| 
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| 	/*
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| 	 * Don't do a long search if the previous block search is still valid,
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| 	 * but skip minor obstructions such as group descriptor backups.
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| 	 */
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| 	if (start_blk && start_blk < ext2fs_blocks_count(fs->super) &&
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| 	    ext2fs_get_free_blocks2(fs, start_blk, start_blk + size, elem_size,
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| 				    bmap, &first_free) == 0)
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| 		return first_free;
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| 
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| 	start_blk = ext2fs_group_first_block2(fs, flexbg_size * flexbg);
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| 	last_grp = group | (flexbg_size - 1);
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| 	if (last_grp > fs->group_desc_count-1)
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| 		last_grp = fs->group_desc_count-1;
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| 	last_blk = ext2fs_group_last_block2(fs, last_grp);
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| 
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| 	/* Find the first available block */
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| 	if (ext2fs_get_free_blocks2(fs, start_blk, last_blk, size,
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| 				    bmap, &first_free) == 0)
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| 		return first_free;
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| 
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| 	if (ext2fs_get_free_blocks2(fs, start_blk, last_blk, elem_size,
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| 				   bmap, &first_free) == 0)
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| 		return first_free;
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| 
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| 	if (ext2fs_get_free_blocks2(fs, 0, last_blk, elem_size, bmap,
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| 				    &first_free) == 0)
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| 		return first_free;
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| 
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| 	return first_free;
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| }
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| 
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| errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
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| 				      ext2fs_block_bitmap bmap)
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| {
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| 	errcode_t	retval;
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| 	blk64_t		group_blk, start_blk, last_blk, new_blk;
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| 	dgrp_t		last_grp = 0;
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| 	int		rem_grps = 0, flexbg_size = 0, table_offset = 0;
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| 
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| 	group_blk = ext2fs_group_first_block2(fs, group);
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| 	last_blk = ext2fs_group_last_block2(fs, group);
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| 
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| 	if (!bmap)
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| 		bmap = fs->block_map;
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| 
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| 	if (ext2fs_has_feature_flex_bg(fs->super) &&
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| 	    fs->super->s_log_groups_per_flex) {
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| 		flexbg_size = 1 << fs->super->s_log_groups_per_flex;
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| 		last_grp = group | (flexbg_size - 1);
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| 		if (last_grp > fs->group_desc_count-1)
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| 			last_grp = fs->group_desc_count-1;
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| 		rem_grps = last_grp - group + 1;
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| 	}
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| 
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| 	/*
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| 	 * Allocate the block and inode bitmaps, if necessary
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| 	 */
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| 	if (fs->stride && !flexbg_size) {
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| 		retval = ext2fs_get_free_blocks2(fs, group_blk, last_blk,
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| 						 1, bmap, &start_blk);
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| 		if (retval)
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| 			return retval;
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| 		start_blk += fs->inode_blocks_per_group;
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| 		start_blk += ((fs->stride * group) %
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| 			      (last_blk - start_blk + 1));
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| 		if (start_blk >= last_blk)
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| 			start_blk = group_blk;
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| 	} else
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| 		start_blk = group_blk;
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| 
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| 	if (flexbg_size) {
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| 		blk64_t prev_block = 0;
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| 
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| 		table_offset = flexbg_size;
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| 		if (group % flexbg_size)
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| 			prev_block = ext2fs_block_bitmap_loc(fs, group - 1) + 1;
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| 		else if (last_grp == fs->group_desc_count-1) {
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| 			/*
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| 			 * If we are allocating for the last flex_bg
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| 			 * keep the metadata tables contiguous
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| 			 */
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| 			table_offset = last_grp & (flexbg_size - 1);
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| 			if (table_offset == 0)
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| 				table_offset = flexbg_size;
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| 			else
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| 				table_offset++;
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| 		}
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| 		/* FIXME: Take backup group descriptor blocks into account
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| 		 * if the flexbg allocations will grow to overlap them... */
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| 		start_blk = flexbg_offset(fs, group, prev_block, bmap,
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| 					  rem_grps, 1);
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| 		last_blk = ext2fs_group_last_block2(fs, last_grp);
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| 	}
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| 
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| 	if (!ext2fs_block_bitmap_loc(fs, group)) {
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| 		retval = ext2fs_get_free_blocks2(fs, start_blk, last_blk,
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| 						 1, bmap, &new_blk);
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| 		if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
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| 			retval = ext2fs_get_free_blocks2(fs, group_blk,
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| 					last_blk, 1, bmap, &new_blk);
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| 		if (retval)
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| 			return retval;
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| 		ext2fs_mark_block_bitmap2(bmap, new_blk);
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| 		ext2fs_block_bitmap_loc_set(fs, group, new_blk);
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| 		if (flexbg_size) {
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| 			dgrp_t gr = ext2fs_group_of_blk2(fs, new_blk);
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| 			ext2fs_bg_free_blocks_count_set(fs, gr, ext2fs_bg_free_blocks_count(fs, gr) - 1);
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| 			ext2fs_free_blocks_count_add(fs->super, -1);
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| 			ext2fs_bg_flags_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
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| 			ext2fs_group_desc_csum_set(fs, gr);
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| 		}
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| 	}
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| 
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| 	if (flexbg_size) {
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| 		blk64_t prev_block = 0;
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| 		if (group % flexbg_size)
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| 			prev_block = ext2fs_inode_bitmap_loc(fs, group - 1) + 1;
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| 		else
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| 			prev_block = ext2fs_block_bitmap_loc(fs, group) +
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| 				table_offset;
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| 		/* FIXME: Take backup group descriptor blocks into account
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| 		 * if the flexbg allocations will grow to overlap them... */
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| 		start_blk = flexbg_offset(fs, group, prev_block, bmap,
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| 					  rem_grps, 1);
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| 		last_blk = ext2fs_group_last_block2(fs, last_grp);
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| 	}
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| 
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| 	if (!ext2fs_inode_bitmap_loc(fs, group)) {
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| 		retval = ext2fs_get_free_blocks2(fs, start_blk, last_blk,
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| 						 1, bmap, &new_blk);
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| 		if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
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| 			retval = ext2fs_get_free_blocks2(fs, group_blk,
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| 					 last_blk, 1, bmap, &new_blk);
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| 		if (retval)
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| 			return retval;
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| 		ext2fs_mark_block_bitmap2(bmap, new_blk);
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| 		ext2fs_inode_bitmap_loc_set(fs, group, new_blk);
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| 		if (flexbg_size) {
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| 			dgrp_t gr = ext2fs_group_of_blk2(fs, new_blk);
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| 			ext2fs_bg_free_blocks_count_set(fs, gr, ext2fs_bg_free_blocks_count(fs, gr) - 1);
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| 			ext2fs_free_blocks_count_add(fs->super, -1);
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| 			ext2fs_bg_flags_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
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| 			ext2fs_group_desc_csum_set(fs, gr);
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| 		}
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| 	}
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| 
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| 	/*
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| 	 * Allocate the inode table
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| 	 */
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| 	if (flexbg_size) {
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| 		blk64_t prev_block = 0;
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| 
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| 		if (group % flexbg_size)
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| 			prev_block = ext2fs_inode_table_loc(fs, group - 1) +
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| 				fs->inode_blocks_per_group;
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| 		else
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| 			prev_block = ext2fs_inode_bitmap_loc(fs, group) +
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| 				table_offset;
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| 
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| 		/* FIXME: Take backup group descriptor blocks into account
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| 		 * if the flexbg allocations will grow to overlap them... */
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| 		group_blk = flexbg_offset(fs, group, prev_block, bmap,
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| 					  rem_grps, fs->inode_blocks_per_group);
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| 		last_blk = ext2fs_group_last_block2(fs, last_grp);
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| 	}
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| 
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| 	if (!ext2fs_inode_table_loc(fs, group)) {
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| 		retval = ext2fs_get_free_blocks2(fs, group_blk, last_blk,
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| 						fs->inode_blocks_per_group,
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| 						bmap, &new_blk);
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| 		if (retval)
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| 			return retval;
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| 
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| 		ext2fs_mark_block_bitmap_range2(bmap,
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| 			new_blk, fs->inode_blocks_per_group);
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| 		if (flexbg_size) {
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| 			blk64_t num, blk;
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| 			num = fs->inode_blocks_per_group;
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| 			blk = new_blk;
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| 			while (num) {
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| 				int gr = ext2fs_group_of_blk2(fs, blk);
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| 				last_blk = ext2fs_group_last_block2(fs, gr);
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| 				blk64_t n = num;
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| 
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| 				if (blk + num > last_blk)
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| 					n = last_blk - blk + 1;
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| 
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| 				ext2fs_bg_free_blocks_count_set(fs, gr,
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| 					ext2fs_bg_free_blocks_count(fs, gr) -
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| 					n/EXT2FS_CLUSTER_RATIO(fs));
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| 				ext2fs_bg_flags_clear(fs, gr,
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| 					EXT2_BG_BLOCK_UNINIT);
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| 				ext2fs_group_desc_csum_set(fs, gr);
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| 				ext2fs_free_blocks_count_add(fs->super, -n);
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| 				blk += n;
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| 				num -= n;
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| 			}
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| 		}
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| 		ext2fs_inode_table_loc_set(fs, group, new_blk);
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| 	}
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| 	ext2fs_group_desc_csum_set(fs, group);
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| 	return 0;
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| }
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| 
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| errcode_t ext2fs_allocate_tables(ext2_filsys fs)
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| {
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| 	errcode_t	retval;
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| 	dgrp_t		i;
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| 	struct ext2fs_numeric_progress_struct progress;
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| 
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| 	if (fs->progress_ops && fs->progress_ops->init)
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| 		(fs->progress_ops->init)(fs, &progress, NULL,
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| 					 fs->group_desc_count);
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| 
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| 	for (i = 0; i < fs->group_desc_count; i++) {
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| 		if (fs->progress_ops && fs->progress_ops->update)
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| 			(fs->progress_ops->update)(fs, &progress, i);
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| 		retval = ext2fs_allocate_group_table(fs, i, fs->block_map);
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| 		if (retval)
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| 			return retval;
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| 	}
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| 	if (fs->progress_ops && fs->progress_ops->close)
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| 		(fs->progress_ops->close)(fs, &progress, NULL);
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| 	return 0;
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| }
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| 
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