diff options
Diffstat (limited to 'drivers/md/dm.c')
| -rw-r--r-- | drivers/md/dm.c | 37 |
1 files changed, 30 insertions, 7 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index f3cc5d99fe8..345e94c10c6 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: |