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Diffstat (limited to 'drivers/md/dm.c')
-rw-r--r--drivers/md/dm.c37
1 files changed, 30 insertions, 7 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index f3cc5d99fe8d..345e94c10c65 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -125,6 +125,10 @@ struct mapped_device {
unsigned long flags;
struct request_queue *queue;
+ unsigned type;
+ /* Protect type against concurrent access. */
+ struct mutex type_lock;
+
struct gendisk *disk;
char name[16];
@@ -1877,8 +1881,10 @@ static struct mapped_device *alloc_dev(int minor)
if (r < 0)
goto bad_minor;
+ md->type = DM_TYPE_NONE;
init_rwsem(&md->io_lock);
mutex_init(&md->suspend_lock);
+ mutex_init(&md->type_lock);
spin_lock_init(&md->deferred_lock);
spin_lock_init(&md->barrier_error_lock);
rwlock_init(&md->map_lock);
@@ -2130,6 +2136,30 @@ int dm_create(int minor, struct mapped_device **result)
return 0;
}
+/*
+ * Functions to manage md->type.
+ * All are required to hold md->type_lock.
+ */
+void dm_lock_md_type(struct mapped_device *md)
+{
+ mutex_lock(&md->type_lock);
+}
+
+void dm_unlock_md_type(struct mapped_device *md)
+{
+ mutex_unlock(&md->type_lock);
+}
+
+void dm_set_md_type(struct mapped_device *md, unsigned type)
+{
+ md->type = type;
+}
+
+unsigned dm_get_md_type(struct mapped_device *md)
+{
+ return md->type;
+}
+
static struct mapped_device *dm_find_md(dev_t dev)
{
struct mapped_device *md;
@@ -2440,13 +2470,6 @@ struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
goto out;
}
- /* cannot change the device type, once a table is bound */
- if (md->map &&
- (dm_table_get_type(md->map) != dm_table_get_type(table))) {
- DMWARN("can't change the device type after a table is bound");
- goto out;
- }
-
map = __bind(md, table, &limits);
out: