From mboxrd@z Thu Jan  1 00:00:00 1970
From: Akira Hayakawa <ruby.wktk@gmail.com>
Subject: [Question] dm-cache table
Date: Mon, 25 Nov 2013 19:54:39 +0900
Message-ID: <52932C6F.5000306@gmail.com>
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Hi,

dm-cache saves the ctr args in .ctr (copy_ctr_copy)
and uses it to make table. 

        case STATUSTYPE_TABLE:
                format_dev_t(buf, cache->metadata_dev->bdev->bd_dev);
                DMEMIT("%s ", buf);
                format_dev_t(buf, cache->cache_dev->bdev->bd_dev);
                DMEMIT("%s ", buf);
                format_dev_t(buf, cache->origin_dev->bdev->bd_dev);
                DMEMIT("%s", buf);

                for (i = 0; i < cache->nr_ctr_args - 1; i++)
                        DMEMIT(" %s", cache->ctr_args[i]);
                if (cache->nr_ctr_args)
                        DMEMIT(" %s", cache->ctr_args[cache->nr_ctr_args - 1]);
        }

If it accepted migrate_threshold in .ctr and the parameter
changed later. The actual value and what is seen in table
become inconsistent right? Is this intentionally designed?

If table is just the copy of the ctr args,
why don't we implement it in dm framework?

Akira