From 36a0456fbf2d9680bf9af81b39daf4a8e22cb1b8 Mon Sep 17 00:00:00 2001 From: Alasdair G Kergon Date: Mon, 31 Oct 2011 20:19:04 +0000 Subject: dm table: add immutable feature Introduce DM_TARGET_IMMUTABLE to indicate that the target type cannot be mixed with any other target type, and once loaded into a device, it cannot be replaced with a table containing a different type. The thin provisioning pool device will use this. Signed-off-by: Alasdair G Kergon --- drivers/md/dm-table.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'drivers/md/dm-table.c') diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 9917141729ef..8e9132130142 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -54,6 +54,7 @@ struct dm_table { sector_t *highs; struct dm_target *targets; + struct target_type *immutable_target_type; unsigned integrity_supported:1; unsigned singleton:1; @@ -780,6 +781,21 @@ int dm_table_add_target(struct dm_table *t, const char *type, return -EINVAL; } + if (t->immutable_target_type) { + if (t->immutable_target_type != tgt->type) { + DMERR("%s: immutable target type %s cannot be mixed with other target types", + dm_device_name(t->md), t->immutable_target_type->name); + return -EINVAL; + } + } else if (dm_target_is_immutable(tgt->type)) { + if (t->num_targets) { + DMERR("%s: immutable target type %s cannot be mixed with other target types", + dm_device_name(t->md), tgt->type->name); + return -EINVAL; + } + t->immutable_target_type = tgt->type; + } + tgt->table = t; tgt->begin = start; tgt->len = len; @@ -937,6 +953,11 @@ unsigned dm_table_get_type(struct dm_table *t) return t->type; } +struct target_type *dm_table_get_immutable_target_type(struct dm_table *t) +{ + return t->immutable_target_type; +} + bool dm_table_request_based(struct dm_table *t) { return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED; -- cgit v1.2.3