+
+/* Create and initialize ext4_group_info data for the given group. */
+int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
+ struct ext4_group_desc *desc)
+{
+ int i, len;
+ int metalen = 0;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_group_info **meta_group_info;
+
+ /*
+ * First check if this group is the first of a reserved block.
+ * If it's true, we have to allocate a new table of pointers
+ * to ext4_group_info structures
+ */
+ if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
+ metalen = sizeof(*meta_group_info) <<
+ EXT4_DESC_PER_BLOCK_BITS(sb);
+ meta_group_info = kmalloc(metalen, GFP_KERNEL);
+ if (meta_group_info == NULL) {
+ printk(KERN_ERR "EXT4-fs: can't allocate mem for a "
+ "buddy group\n");
+ goto exit_meta_group_info;
+ }
+ sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] =
+ meta_group_info;
+ }
+
+ /*
+ * calculate needed size. if change bb_counters size,
+ * don't forget about ext4_mb_generate_buddy()
+ */
+ len = offsetof(typeof(**meta_group_info),
+ bb_counters[sb->s_blocksize_bits + 2]);
+
+ meta_group_info =
+ sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)];
+ i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
+
+ meta_group_info[i] = kzalloc(len, GFP_KERNEL);
+ if (meta_group_info[i] == NULL) {
+ printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
+ goto exit_group_info;
+ }
+ set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
+ &(meta_group_info[i]->bb_state));
+
+ /*
+ * initialize bb_free to be able to skip
+ * empty groups without initialization
+ */
+ if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+ meta_group_info[i]->bb_free =
+ ext4_free_blocks_after_init(sb, group, desc);
+ } else {
+ meta_group_info[i]->bb_free =
+ le16_to_cpu(desc->bg_free_blocks_count);
+ }
+
+ INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
+
+#ifdef DOUBLE_CHECK
+ {
+ struct buffer_head *bh;
+ meta_group_info[i]->bb_bitmap =
+ kmalloc(sb->s_blocksize, GFP_KERNEL);
+ BUG_ON(meta_group_info[i]->bb_bitmap == NULL);
+ bh = ext4_read_block_bitmap(sb, group);
+ BUG_ON(bh == NULL);
+ memcpy(meta_group_info[i]->bb_bitmap, bh->b_data,
+ sb->s_blocksize);
+ put_bh(bh);
+ }
+#endif
+
+ return 0;
+
+exit_group_info:
+ /* If a meta_group_info table has been allocated, release it now */
+ if (group % EXT4_DESC_PER_BLOCK(sb) == 0)
+ kfree(sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)]);
+exit_meta_group_info:
+ return -ENOMEM;
+} /* ext4_mb_add_groupinfo */
+
+/*
+ * Add a group to the existing groups.
+ * This function is used for online resize
+ */
+int ext4_mb_add_more_groupinfo(struct super_block *sb, ext4_group_t group,
+ struct ext4_group_desc *desc)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct inode *inode = sbi->s_buddy_cache;
+ int blocks_per_page;
+ int block;
+ int pnum;
+ struct page *page;
+ int err;
+
+ /* Add group based on group descriptor*/
+ err = ext4_mb_add_groupinfo(sb, group, desc);
+ if (err)
+ return err;
+
+ /*
+ * Cache pages containing dynamic mb_alloc datas (buddy and bitmap
+ * datas) are set not up to date so that they will be re-initilaized
+ * during the next call to ext4_mb_load_buddy
+ */
+
+ /* Set buddy page as not up to date */
+ blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
+ block = group * 2;
+ pnum = block / blocks_per_page;
+ page = find_get_page(inode->i_mapping, pnum);
+ if (page != NULL) {
+ ClearPageUptodate(page);
+ page_cache_release(page);
+ }
+
+ /* Set bitmap page as not up to date */
+ block++;
+ pnum = block / blocks_per_page;
+ page = find_get_page(inode->i_mapping, pnum);
+ if (page != NULL) {
+ ClearPageUptodate(page);
+ page_cache_release(page);
+ }
+
+ return 0;
+}
+
+/*
+ * Update an existing group.
+ * This function is used for online resize
+ */
+void ext4_mb_update_group_info(struct ext4_group_info *grp, ext4_grpblk_t add)
+{
+ grp->bb_free += add;
+}
+