/* * alloc_tables.c --- Allocate tables for a newly initialized * filesystem. Used by mke2fs when initializing a filesystem * * Copyright (C) 1996 Theodore Ts'o. * * %Begin-Header% * This file may be redistributed under the terms of the GNU Public * License. * %End-Header% */ #include #include #if HAVE_UNISTD_H #include #endif #include #include #if HAVE_SYS_STAT_H #include #endif #if HAVE_SYS_TYPES_H #include #endif #include "ext2_fs.h" #include "ext2fs.h" /* * This routine searches for free blocks that can allocate a full * group of bitmaps or inode tables for a flexbg group. Returns the * block number with a correct offset were the bitmaps and inode * tables can be allocated continously and in order. */ static blk_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk_t start_blk, ext2fs_block_bitmap bmap, int offset, int size) { int flexbg, flexbg_size, elem_size; blk_t last_blk, first_free = 0; dgrp_t last_grp; flexbg_size = 1 << fs->super->s_log_groups_per_flex; flexbg = group / flexbg_size; if (size > (int) (fs->super->s_blocks_per_group / 8)) size = (int) fs->super->s_blocks_per_group / 8; if (offset) offset -= 1; /* * Don't do a long search if the previous block * search is still valid. */ if (start_blk && group % flexbg_size) { if (size > flexbg_size) elem_size = fs->inode_blocks_per_group; else elem_size = 1; if (ext2fs_test_block_bitmap_range(bmap, start_blk + elem_size, size)) return start_blk + elem_size; } start_blk = ext2fs_group_first_block(fs, flexbg_size * flexbg); last_grp = group | (flexbg_size - 1); if (last_grp > fs->group_desc_count) last_grp = fs->group_desc_count; last_blk = ext2fs_group_last_block(fs, last_grp); /* Find the first available block */ if (ext2fs_get_free_blocks(fs, start_blk, last_blk, 1, bmap, &first_free)) return first_free; if (ext2fs_get_free_blocks(fs, first_free + offset, last_blk, size, bmap, &first_free)) return first_free; return first_free; } errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group, ext2fs_block_bitmap bmap) { errcode_t retval; blk_t group_blk, start_blk, last_blk, new_blk, blk; dgrp_t last_grp = 0; int j, rem_grps = 0, flexbg_size = 0; group_blk = ext2fs_group_first_block(fs, group); last_blk = ext2fs_group_last_block(fs, group); if (!bmap) bmap = fs->block_map; if (EXT2_HAS_INCOMPAT_FEATURE(fs->super, EXT4_FEATURE_INCOMPAT_FLEX_BG) && fs->super->s_log_groups_per_flex) { flexbg_size = 1 << fs->super->s_log_groups_per_flex; last_grp = group | (flexbg_size - 1); rem_grps = last_grp - group; if (last_grp > fs->group_desc_count) last_grp = fs->group_desc_count; } /* * Allocate the block and inode bitmaps, if necessary */ if (fs->stride) { retval = ext2fs_get_free_blocks(fs, group_blk, last_blk, 1, bmap, &start_blk); if (retval) return retval; start_blk += fs->inode_blocks_per_group; start_blk += ((fs->stride * group) % (last_blk - start_blk + 1)); if (start_blk >= last_blk) start_blk = group_blk; } else start_blk = group_blk; if (flexbg_size) { int prev_block = 0; if (group && fs->group_desc[group-1].bg_block_bitmap) prev_block = fs->group_desc[group-1].bg_block_bitmap; start_blk = flexbg_offset(fs, group, prev_block, bmap, 0, rem_grps); last_blk = ext2fs_group_last_block(fs, last_grp); } if (!fs->group_desc[group].bg_block_bitmap) { retval = ext2fs_get_free_blocks(fs, start_blk, last_blk, 1, bmap, &new_blk); if (retval == EXT2_ET_BLOCK_ALLOC_FAIL) retval = ext2fs_get_free_blocks(fs, group_blk, last_blk, 1, bmap, &new_blk); if (retval) return retval; ext2fs_mark_block_bitmap(bmap, new_blk); fs->group_desc[group].bg_block_bitmap = new_blk; if (flexbg_size) { dgrp_t gr = ext2fs_group_of_blk(fs, new_blk); fs->group_desc[gr].bg_free_blocks_count--; fs->super->s_free_blocks_count--; fs->group_desc[gr].bg_flags &= ~EXT2_BG_BLOCK_UNINIT; ext2fs_group_desc_csum_set(fs, gr); } } if (flexbg_size) { int prev_block = 0; if (group && fs->group_desc[group-1].bg_inode_bitmap) prev_block = fs->group_desc[group-1].bg_inode_bitmap; start_blk = flexbg_offset(fs, group, prev_block, bmap, flexbg_size, rem_grps); last_blk = ext2fs_group_last_block(fs, last_grp); } if (!fs->group_desc[group].bg_inode_bitmap) { retval = ext2fs_get_free_blocks(fs, start_blk, last_blk, 1, bmap, &new_blk); if (retval == EXT2_ET_BLOCK_ALLOC_FAIL) retval = ext2fs_get_free_blocks(fs, group_blk, last_blk, 1, bmap, &new_blk); if (retval) return retval; ext2fs_mark_block_bitmap(bmap, new_blk); fs->group_desc[group].bg_inode_bitmap = new_blk; if (flexbg_size) { dgrp_t gr = ext2fs_group_of_blk(fs, new_blk); fs->group_desc[gr].bg_free_blocks_count--; fs->super->s_free_blocks_count--; fs->group_desc[gr].bg_flags &= ~EXT2_BG_BLOCK_UNINIT; ext2fs_group_desc_csum_set(fs, gr); } } /* * Allocate the inode table */ if (flexbg_size) { int prev_block = 0; if (group && fs->group_desc[group-1].bg_inode_table) prev_block = fs->group_desc[group-1].bg_inode_table; group_blk = flexbg_offset(fs, group, prev_block, bmap, flexbg_size * 2, fs->inode_blocks_per_group * rem_grps); last_blk = ext2fs_group_last_block(fs, last_grp); } if (!fs->group_desc[group].bg_inode_table) { retval = ext2fs_get_free_blocks(fs, group_blk, last_blk, fs->inode_blocks_per_group, bmap, &new_blk); if (retval) return retval; for (j=0, blk = new_blk; j < fs->inode_blocks_per_group; j++, blk++) { ext2fs_mark_block_bitmap(bmap, blk); if (flexbg_size) { dgrp_t gr = ext2fs_group_of_blk(fs, blk); fs->group_desc[gr].bg_free_blocks_count--; fs->super->s_free_blocks_count--; fs->group_desc[gr].bg_flags &= ~EXT2_BG_BLOCK_UNINIT; ext2fs_group_desc_csum_set(fs, gr); } } fs->group_desc[group].bg_inode_table = new_blk; } ext2fs_group_desc_csum_set(fs, group); return 0; } errcode_t ext2fs_allocate_tables(ext2_filsys fs) { errcode_t retval; dgrp_t i; for (i = 0; i < fs->group_desc_count; i++) { retval = ext2fs_allocate_group_table(fs, i, fs->block_map); if (retval) return retval; } return 0; }