Clarify the comment regarding the "next" field in struct dm_target_spec. The "next" field has different behavior if you're performing a DM_TABLE_STATUS command than it does if you're performing a DM_TABLE_LOAD command. See populate_table() and retrieve_status() in drivers/md/dm-ioctl.c for more details on how this field is used. --- diff/include/linux/dm-ioctl.h 2004-03-23 15:27:49.000000000 -0600 +++ source/include/linux/dm-ioctl.h 2004-03-23 16:11:16.000000000 -0600 @@ -129,8 +129,14 @@ int32_t status; /* used when reading from kernel only */ /* - * Offset in bytes (from the start of this struct) to - * next target_spec. + * Location of the next dm_target_spec. + * - When specifying targets on a DM_TABLE_LOAD command, this value is + * the number of bytes from the start of the "current" dm_target_spec + * to the start of the "next" dm_target_spec. + * - When retrieving targets on a DM_TABLE_STATUS command, this value + * is the number of bytes from the start of the first dm_target_spec + * (that follows the dm_ioctl struct) to the start of the "next" + * dm_target_spec. */ uint32_t next;
