diff options
Diffstat (limited to 'include/block/block_int.h')
| -rw-r--r-- | include/block/block_int.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/block/block_int.h b/include/block/block_int.h index 7571c0aaaf..71183cc76e 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -87,7 +87,11 @@ struct BlockDriver { const char *format_name; int instance_size; - /* set to true if the BlockDriver is a block filter */ + /* set to true if the BlockDriver is a block filter. Block filters pass + * certain callbacks that refer to data (see block.c) to their bs->file if + * the driver doesn't implement them. Drivers that do not wish to forward + * must implement them and return -ENOTSUP. + */ bool is_filter; /* for snapshots block filter like Quorum can implement the * following recursive callback. |