diff options
| -rw-r--r-- | drivers/md/dm-table.c | 16 | ||||
| -rw-r--r-- | include/linux/device-mapper.h | 14 |
2 files changed, 26 insertions, 4 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 81cbbf375bd..2ec3482e942 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -55,6 +55,7 @@ struct dm_table { struct dm_target *targets; unsigned integrity_supported:1; + unsigned singleton:1; /* * Indicates the rw permissions for the new logical @@ -740,6 +741,12 @@ int dm_table_add_target(struct dm_table *t, const char *type, char **argv; struct dm_target *tgt; + if (t->singleton) { + DMERR("%s: target type %s must appear alone in table", + dm_device_name(t->md), t->targets->type->name); + return -EINVAL; + } + if ((r = check_space(t))) return r; @@ -758,6 +765,15 @@ int dm_table_add_target(struct dm_table *t, const char *type, return -EINVAL; } + if (dm_target_needs_singleton(tgt->type)) { + if (t->num_targets) { + DMERR("%s: target type %s must appear alone in table", + dm_device_name(t->md), type); + return -EINVAL; + } + t->singleton = 1; + } + tgt->table = t; tgt->begin = start; tgt->len = len; diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 622678ccb5e..294e78a7fcc 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -128,10 +128,6 @@ void dm_put_device(struct dm_target *ti, struct dm_dev *d); * Information about a target type */ -/* - * Target features - */ - struct target_type { uint64_t features; const char *name; @@ -160,6 +156,16 @@ struct target_type { struct list_head list; }; +/* + * Target features + */ + +/* + * Any table that contains an instance of this target must have only one. + */ +#define DM_TARGET_SINGLETON 0x00000001 +#define dm_target_needs_singleton(type) ((type)->features & DM_TARGET_SINGLETON) + struct dm_target { struct dm_table *table; struct target_type *type; |