dm ioctl: refactor dm_table_complete

This change unifies the various checks and finalization that occurs on a
table prior to use.  By doing so, it allows table construction without
traversing the dm-ioctl interface.
Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

drivers/md/dm-ioctl.c

@@ -1131,28 +1131,9 @@ static int populate_table(struct dm_table *table,
 		next = spec->next;
 	}
 
-	r = dm_table_set_type(table);
-	if (r) {
-		DMWARN("unable to set table type");
-		return r;
-	}
-
 	return dm_table_complete(table);
 }
 
-static int table_prealloc_integrity(struct dm_table *t,
-				    struct mapped_device *md)
-{
-	struct list_head *devices = dm_table_get_devices(t);
-	struct dm_dev_internal *dd;
-
-	list_for_each_entry(dd, devices, list)
-		if (bdev_get_integrity(dd->dm_dev.bdev))
-			return blk_integrity_register(dm_disk(md), NULL);
-
-	return 0;
-}
-
 static int table_load(struct dm_ioctl *param, size_t param_size)
 {
 	int r;
@@ -1174,21 +1155,6 @@ static int table_load(struct dm_ioctl *param, size_t param_size)
 		goto out;
 	}
 
-	r = table_prealloc_integrity(t, md);
-	if (r) {
-		DMERR("%s: could not register integrity profile.",
-		      dm_device_name(md));
-		dm_table_destroy(t);
-		goto out;
-	}
-
-	r = dm_table_alloc_md_mempools(t);
-	if (r) {
-		DMWARN("unable to allocate mempools for this table");
-		dm_table_destroy(t);
-		goto out;
-	}
-
 	/* Protect md->type and md->queue against concurrent table loads. */
 	dm_lock_md_type(md);
 	if (dm_get_md_type(md) == DM_TYPE_NONE)

drivers/md/dm-table.c

@@ -245,7 +245,7 @@ void dm_table_destroy(struct dm_table *t)
 		msleep(1);
 	smp_mb();
 
-	/* free the indexes (see dm_table_complete) */
+	/* free the indexes */
 	if (t->depth >= 2)
 		vfree(t->index[t->depth - 2]);
 
@@ -778,7 +778,7 @@ int dm_table_add_target(struct dm_table *t, const char *type,
 	return r;
 }
 
-int dm_table_set_type(struct dm_table *t)
+static int dm_table_set_type(struct dm_table *t)
 {
 	unsigned i;
 	unsigned bio_based = 0, request_based = 0;
@@ -900,7 +900,7 @@ static int setup_indexes(struct dm_table *t)
 /*
  * Builds the btree to index the map.
  */
-int dm_table_complete(struct dm_table *t)
+static int dm_table_build_index(struct dm_table *t)
 {
 	int r = 0;
 	unsigned int leaf_nodes;
@@ -919,6 +919,55 @@ int dm_table_complete(struct dm_table *t)
 	return r;
 }
 
+/*
+ * Register the mapped device for blk_integrity support if
+ * the underlying devices support it.
+ */
+static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
+{
+	struct list_head *devices = dm_table_get_devices(t);
+	struct dm_dev_internal *dd;
+
+	list_for_each_entry(dd, devices, list)
+		if (bdev_get_integrity(dd->dm_dev.bdev))
+			return blk_integrity_register(dm_disk(md), NULL);
+
+	return 0;
+}
+
+/*
+ * Prepares the table for use by building the indices,
+ * setting the type, and allocating mempools.
+ */
+int dm_table_complete(struct dm_table *t)
+{
+	int r;
+
+	r = dm_table_set_type(t);
+	if (r) {
+		DMERR("unable to set table type");
+		return r;
+	}
+
+	r = dm_table_build_index(t);
+	if (r) {
+		DMERR("unable to build btrees");
+		return r;
+	}
+
+	r = dm_table_prealloc_integrity(t, t->md);
+	if (r) {
+		DMERR("could not register integrity profile.");
+		return r;
+	}
+
+	r = dm_table_alloc_md_mempools(t);
+	if (r)
+		DMERR("unable to allocate mempools");
+
+	return r;
+}
+
 static DEFINE_MUTEX(_event_lock);
 void dm_table_event_callback(struct dm_table *t,
 			     void (*fn)(void *), void *context)

drivers/md/dm.h

@@ -59,7 +59,6 @@ void dm_table_postsuspend_targets(struct dm_table *t);
 int dm_table_resume_targets(struct dm_table *t);
 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
 int dm_table_any_busy_target(struct dm_table *t);
-int dm_table_set_type(struct dm_table *t);
 unsigned dm_table_get_type(struct dm_table *t);
 bool dm_table_request_based(struct dm_table *t);
 int dm_table_alloc_md_mempools(struct dm_table *t);