[PATCH 1/7] dm: don't change md if dm_table_set_restrictions() fails

[Benjamin Marzinski <bmarzins@redhat.com>]

__bind was changing the disk capacity, geometry and mempools of the
mapped device before calling dm_table_set_restrictions() which could
fail, forcing dm to drop the new table. Failing here would leave the
device using the old table but with the wrong capacity and mempools.

Move dm_table_set_restrictions() earlier in __bind(). Since it needs the
capacity to be set, save the old version and restore it on failure.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
 drivers/md/dm.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 5ab7574c0c76..f5c5ccb6f8d2 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2421,21 +2421,29 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
 			       struct queue_limits *limits)
 {
 	struct dm_table *old_map;
-	sector_t size;
+	sector_t size, old_size;
 	int ret;
 
 	lockdep_assert_held(&md->suspend_lock);
 
 	size = dm_table_get_size(t);
 
+	old_size = dm_get_size(md);
+	set_capacity(md->disk, size);
+
+	ret = dm_table_set_restrictions(t, md->queue, limits);
+	if (ret) {
+		set_capacity(md->disk, old_size);
+		old_map = ERR_PTR(ret);
+		goto out;
+	}
+
 	/*
 	 * Wipe any geometry if the size of the table changed.
 	 */
-	if (size != dm_get_size(md))
+	if (size != old_size)
 		memset(&md->geometry, 0, sizeof(md->geometry));
 
-	set_capacity(md->disk, size);
-
 	dm_table_event_callback(t, event_callback, md);
 
 	if (dm_table_request_based(t)) {
@@ -2468,12 +2476,6 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
 		t->mempools = NULL;
 	}
 
-	ret = dm_table_set_restrictions(t, md->queue, limits);
-	if (ret) {
-		old_map = ERR_PTR(ret);
-		goto out;
-	}
-
 	old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
 	rcu_assign_pointer(md->map, (void *)t);
 	md->immutable_target_type = dm_table_get_immutable_target_type(t);
-- 
2.48.1