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-rw-r--r--lib/ext2fs/alloc_tables.c278
1 files changed, 278 insertions, 0 deletions
diff --git a/lib/ext2fs/alloc_tables.c b/lib/ext2fs/alloc_tables.c
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+++ b/lib/ext2fs/alloc_tables.c
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+/*
+ * 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 Library
+ * General Public License, version 2.
+ * %End-Header%
+ */
+
+#include "config.h"
+#include <stdio.h>
+#include <string.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <fcntl.h>
+#include <time.h>
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#include "ext2_fs.h"
+#include "ext2fs.h"
+#include "ext2fsP.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 continuously and in order.
+ */
+static blk64_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk64_t start_blk,
+ ext2fs_block_bitmap bmap, int rem_grp,
+ int elem_size)
+{
+ int flexbg, flexbg_size, size;
+ blk64_t last_blk, first_free = 0;
+ dgrp_t last_grp;
+
+ flexbg_size = 1U << fs->super->s_log_groups_per_flex;
+ flexbg = group / flexbg_size;
+ size = rem_grp * elem_size;
+
+ if (size > (int) (fs->super->s_blocks_per_group / 4))
+ size = (int) fs->super->s_blocks_per_group / 4;
+
+ /*
+ * Don't do a long search if the previous block search is still valid,
+ * but skip minor obstructions such as group descriptor backups.
+ */
+ if (start_blk && start_blk < ext2fs_blocks_count(fs->super) &&
+ ext2fs_get_free_blocks2(fs, start_blk, start_blk + size, elem_size,
+ bmap, &first_free) == 0)
+ return first_free;
+
+ start_blk = ext2fs_group_first_block2(fs, flexbg_size * flexbg);
+ last_grp = group | (flexbg_size - 1);
+ if (last_grp > fs->group_desc_count-1)
+ last_grp = fs->group_desc_count-1;
+ last_blk = ext2fs_group_last_block2(fs, last_grp);
+
+ /* Find the first available block */
+ if (ext2fs_get_free_blocks2(fs, start_blk, last_blk, size,
+ bmap, &first_free) == 0)
+ return first_free;
+
+ if (ext2fs_get_free_blocks2(fs, start_blk, last_blk, elem_size,
+ bmap, &first_free) == 0)
+ return first_free;
+
+ if (ext2fs_get_free_blocks2(fs, 0, last_blk, elem_size, bmap,
+ &first_free) == 0)
+ 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;
+ blk64_t group_blk, start_blk, last_blk, new_blk;
+ dgrp_t last_grp = 0;
+ int rem_grps = 0, flexbg_size = 0, table_offset = 0;
+
+ group_blk = ext2fs_group_first_block2(fs, group);
+ last_blk = ext2fs_group_last_block2(fs, group);
+
+ if (!bmap)
+ bmap = fs->block_map;
+
+ if (ext2fs_has_feature_flex_bg(fs->super) &&
+ fs->super->s_log_groups_per_flex) {
+ flexbg_size = 1U << fs->super->s_log_groups_per_flex;
+ last_grp = group | (flexbg_size - 1);
+ if (last_grp > fs->group_desc_count-1)
+ last_grp = fs->group_desc_count-1;
+ rem_grps = last_grp - group + 1;
+ }
+
+ /*
+ * Allocate the block and inode bitmaps, if necessary
+ */
+ if (fs->stride && !flexbg_size) {
+ retval = ext2fs_get_free_blocks2(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) {
+ blk64_t prev_block = 0;
+
+ table_offset = flexbg_size;
+ if (group % flexbg_size)
+ prev_block = ext2fs_block_bitmap_loc(fs, group - 1) + 1;
+ else if (last_grp == fs->group_desc_count-1) {
+ /*
+ * If we are allocating for the last flex_bg
+ * keep the metadata tables contiguous
+ */
+ table_offset = last_grp & (flexbg_size - 1);
+ if (table_offset == 0)
+ table_offset = flexbg_size;
+ else
+ table_offset++;
+ }
+ /* FIXME: Take backup group descriptor blocks into account
+ * if the flexbg allocations will grow to overlap them... */
+ start_blk = flexbg_offset(fs, group, prev_block, bmap,
+ rem_grps, 1);
+ last_blk = ext2fs_group_last_block2(fs, last_grp);
+ }
+
+ if (!ext2fs_block_bitmap_loc(fs, group)) {
+ retval = ext2fs_get_free_blocks2(fs, start_blk, last_blk,
+ 1, bmap, &new_blk);
+ if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
+ retval = ext2fs_get_free_blocks2(fs, group_blk,
+ last_blk, 1, bmap, &new_blk);
+ if (retval)
+ return retval;
+ ext2fs_mark_block_bitmap2(bmap, new_blk);
+ ext2fs_block_bitmap_loc_set(fs, group, new_blk);
+ if (flexbg_size) {
+ dgrp_t gr = ext2fs_group_of_blk2(fs, new_blk);
+ ext2fs_bg_free_blocks_count_set(fs, gr, ext2fs_bg_free_blocks_count(fs, gr) - 1);
+ ext2fs_free_blocks_count_add(fs->super, -1);
+ ext2fs_bg_flags_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
+ ext2fs_group_desc_csum_set(fs, gr);
+ }
+ }
+
+ if (flexbg_size) {
+ blk64_t prev_block = 0;
+ if (group % flexbg_size)
+ prev_block = ext2fs_inode_bitmap_loc(fs, group - 1) + 1;
+ else
+ prev_block = ext2fs_block_bitmap_loc(fs, group) +
+ table_offset;
+ /* FIXME: Take backup group descriptor blocks into account
+ * if the flexbg allocations will grow to overlap them... */
+ start_blk = flexbg_offset(fs, group, prev_block, bmap,
+ rem_grps, 1);
+ last_blk = ext2fs_group_last_block2(fs, last_grp);
+ }
+
+ if (!ext2fs_inode_bitmap_loc(fs, group)) {
+ retval = ext2fs_get_free_blocks2(fs, start_blk, last_blk,
+ 1, bmap, &new_blk);
+ if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
+ retval = ext2fs_get_free_blocks2(fs, group_blk,
+ last_blk, 1, bmap, &new_blk);
+ if (retval)
+ return retval;
+ ext2fs_mark_block_bitmap2(bmap, new_blk);
+ ext2fs_inode_bitmap_loc_set(fs, group, new_blk);
+ if (flexbg_size) {
+ dgrp_t gr = ext2fs_group_of_blk2(fs, new_blk);
+ ext2fs_bg_free_blocks_count_set(fs, gr, ext2fs_bg_free_blocks_count(fs, gr) - 1);
+ ext2fs_free_blocks_count_add(fs->super, -1);
+ ext2fs_bg_flags_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
+ ext2fs_group_desc_csum_set(fs, gr);
+ }
+ }
+
+ /*
+ * Allocate the inode table
+ */
+ if (flexbg_size) {
+ blk64_t prev_block = 0;
+
+ if (group % flexbg_size)
+ prev_block = ext2fs_inode_table_loc(fs, group - 1) +
+ fs->inode_blocks_per_group;
+ else
+ prev_block = ext2fs_inode_bitmap_loc(fs, group) +
+ table_offset;
+
+ /* FIXME: Take backup group descriptor blocks into account
+ * if the flexbg allocations will grow to overlap them... */
+ group_blk = flexbg_offset(fs, group, prev_block, bmap,
+ rem_grps, fs->inode_blocks_per_group);
+ last_blk = ext2fs_group_last_block2(fs, last_grp);
+ }
+
+ if (!ext2fs_inode_table_loc(fs, group)) {
+ retval = ext2fs_get_free_blocks2(fs, group_blk, last_blk,
+ fs->inode_blocks_per_group,
+ bmap, &new_blk);
+ if (retval)
+ return retval;
+
+ ext2fs_mark_block_bitmap_range2(bmap,
+ new_blk, fs->inode_blocks_per_group);
+ if (flexbg_size) {
+ blk64_t num, blk;
+ num = fs->inode_blocks_per_group;
+ blk = new_blk;
+ while (num) {
+ int gr = ext2fs_group_of_blk2(fs, blk);
+ last_blk = ext2fs_group_last_block2(fs, gr);
+ blk64_t n = num;
+
+ if (blk + num > last_blk)
+ n = last_blk - blk + 1;
+
+ ext2fs_bg_free_blocks_count_set(fs, gr,
+ ext2fs_bg_free_blocks_count(fs, gr) -
+ n/EXT2FS_CLUSTER_RATIO(fs));
+ ext2fs_bg_flags_clear(fs, gr,
+ EXT2_BG_BLOCK_UNINIT);
+ ext2fs_group_desc_csum_set(fs, gr);
+ ext2fs_free_blocks_count_add(fs->super, -n);
+ blk += n;
+ num -= n;
+ }
+ }
+ ext2fs_inode_table_loc_set(fs, group, 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;
+ struct ext2fs_numeric_progress_struct progress;
+
+ if (fs->progress_ops && fs->progress_ops->init)
+ (fs->progress_ops->init)(fs, &progress, NULL,
+ fs->group_desc_count);
+
+ for (i = 0; i < fs->group_desc_count; i++) {
+ if (fs->progress_ops && fs->progress_ops->update)
+ (fs->progress_ops->update)(fs, &progress, i);
+ retval = ext2fs_allocate_group_table(fs, i, fs->block_map);
+ if (retval)
+ return retval;
+ }
+ if (fs->progress_ops && fs->progress_ops->close)
+ (fs->progress_ops->close)(fs, &progress, NULL);
+ return 0;
+}
+
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