static int btt_freelist_init()

in btt.c [535:603]

• 41 lines of code
• 12 McCabe index (conditional complexity)

static int btt_freelist_init(struct arena_info *arena)
{
	int new, ret;
	struct log_entry log_new;
	u32 i, map_entry, log_oldmap, log_newmap;

	arena->freelist = kcalloc(arena->nfree, sizeof(struct free_entry),
					GFP_KERNEL);
	if (!arena->freelist)
		return -ENOMEM;

	for (i = 0; i < arena->nfree; i++) {
		new = btt_log_read(arena, i, &log_new, LOG_NEW_ENT);
		if (new < 0)
			return new;

		/* old and new map entries with any flags stripped out */
		log_oldmap = ent_lba(le32_to_cpu(log_new.old_map));
		log_newmap = ent_lba(le32_to_cpu(log_new.new_map));

		/* sub points to the next one to be overwritten */
		arena->freelist[i].sub = 1 - new;
		arena->freelist[i].seq = nd_inc_seq(le32_to_cpu(log_new.seq));
		arena->freelist[i].block = log_oldmap;

		/*
		 * FIXME: if error clearing fails during init, we want to make
		 * the BTT read-only
		 */
		if (ent_e_flag(le32_to_cpu(log_new.old_map)) &&
		    !ent_normal(le32_to_cpu(log_new.old_map))) {
			arena->freelist[i].has_err = 1;
			ret = arena_clear_freelist_error(arena, i);
			if (ret)
				dev_err_ratelimited(to_dev(arena),
					"Unable to clear known errors\n");
		}

		/* This implies a newly created or untouched flog entry */
		if (log_oldmap == log_newmap)
			continue;

		/* Check if map recovery is needed */
		ret = btt_map_read(arena, le32_to_cpu(log_new.lba), &map_entry,
				NULL, NULL, 0);
		if (ret)
			return ret;

		/*
		 * The map_entry from btt_read_map is stripped of any flag bits,
		 * so use the stripped out versions from the log as well for
		 * testing whether recovery is needed. For restoration, use the
		 * 'raw' version of the log entries as that captured what we
		 * were going to write originally.
		 */
		if ((log_newmap != map_entry) && (log_oldmap == map_entry)) {
			/*
			 * Last transaction wrote the flog, but wasn't able
			 * to complete the map write. So fix up the map.
			 */
			ret = btt_map_write(arena, le32_to_cpu(log_new.lba),
					le32_to_cpu(log_new.new_map), 0, 0, 0);
			if (ret)
				return ret;
		}
	}

	return 0;
}