From: Mike Snitzer <snitzer@redhat.com>
Date: Fri, 27 Jul 2012 14:07:59 +0000 (+0100)
Subject: dm thin: provide specific errors for two table load failure cases
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=f09996c993e256fce4b920588959866998d51250;p=linux-beck.git

dm thin: provide specific errors for two table load failure cases

Provide specific error message strings for two pool_ctr() failure cases
that currently give just "Unknown error".

Reference: test_two_pools_pointing_to_the_same_metadata_fails and
test_different_pool_cant_replace_pool in thinp-test-suite.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
---

diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 0bb9e646e215..e89f8e7d8a33 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -1828,15 +1828,19 @@ static struct pool *__pool_find(struct mapped_device *pool_md,
 	struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev);
 
 	if (pool) {
-		if (pool->pool_md != pool_md)
+		if (pool->pool_md != pool_md) {
+			*error = "metadata device already in use by a pool";
 			return ERR_PTR(-EBUSY);
+		}
 		__pool_inc(pool);
 
 	} else {
 		pool = __pool_table_lookup(pool_md);
 		if (pool) {
-			if (pool->md_dev != metadata_dev)
+			if (pool->md_dev != metadata_dev) {
+				*error = "different pool cannot replace a pool";
 				return ERR_PTR(-EINVAL);
+			}
 			__pool_inc(pool);
 
 		} else {