Re: [PATCH bpf-next v1] tools/bpftool: create map of maps

From: Quentin Monnet
Date: Tue Mar 05 2019 - 13:27:58 EST


2019-03-05 17:38 UTC+0100 ~ Alban Crequy <alban.crequy@xxxxxxxxx>
> From: Alban Crequy <alban@xxxxxxxxxx>
>
> Before this patch, there was no way to fill attr.inner_map_fd, necessary
> for array_of_maps or hash_of_maps.
>
> This patch adds keyword 'innermap' to pass the innermap, either as an id
> or as a pinned map.
>
> Example of commands:
>
> $ sudo bpftool map create /sys/fs/bpf/innermap type hash \
> key 8 value 8 entries 64 name innermap flags 1
> $ sudo bpftool map create /sys/fs/bpf/outermap type hash_of_maps \
> innermap pinned /sys/fs/bpf/innermap key 64 value 4 \
> entries 64 name myoutermap flags 1
> $ sudo bpftool map show pinned /sys/fs/bpf/outermap
> 47: hash_of_maps name myoutermap flags 0x1
> key 64B value 4B max_entries 64 memlock 12288B
>
> Documentation and bash completion updated as well.
>
> Signed-off-by: Alban Crequy <alban@xxxxxxxxxx>

Thanks Alban!

> ---
> tools/bpf/bpftool/Documentation/bpftool-prog.rst | 2 +-
> tools/bpf/bpftool/bash-completion/bpftool | 13 +++++++++++++
> tools/bpf/bpftool/map.c | 5 ++++-
> 3 files changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
> index 9386bd6e0396..35902ab95cc5 100644
> --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
> +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
> @@ -25,7 +25,7 @@ PROG COMMANDS
> | **bpftool** **prog dump xlated** *PROG* [{**file** *FILE* | **opcodes** | **visual** | **linum**}]
> | **bpftool** **prog dump jited** *PROG* [{**file** *FILE* | **opcodes** | **linum**}]
> | **bpftool** **prog pin** *PROG* *FILE*
> -| **bpftool** **prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*]
> +| **bpftool** **prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] [**innermap** MAP]

This page is the documentation for "bpftool prog" commands. You want
"bpftool map" (tools/bpf/bpftool/Documentation/bpftool-map.rst) instead.

You also need to update the description line for the "bpftool map
create" command further down in the bpftool-map.rst page. And could you
please add a sentence to that description to explain what the argument
is for?

> | **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*]
> | **bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*]
> | **bpftool** **prog tracelog**
> diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
> index b803827d01e8..dcdc39510dc3 100644
> --- a/tools/bpf/bpftool/bash-completion/bpftool
> +++ b/tools/bpf/bpftool/bash-completion/bpftool
> @@ -461,6 +461,18 @@ _bpftool()
> _sysfs_get_netdevs
> return 0
> ;;
> + innermap)
> + COMPREPLY+=( $( compgen -W "id pinned" -- "$cur" ) )
> + return 0
> + ;;
> + id)
> + _bpftool_get_map_ids
> + return 0
> + ;;
> + pinned)
> + _filedir
> + return 0
> + ;;

No need to add completion here for "pinned", it is handled already [0].

[0]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/bpf/bpftool/bash-completion/bpftool?h=v5.0#n172

> *)
> _bpftool_once_attr 'type'
> _bpftool_once_attr 'key'
> @@ -469,6 +481,7 @@ _bpftool()
> _bpftool_once_attr 'name'
> _bpftool_once_attr 'flags'
> _bpftool_once_attr 'dev'
> + _bpftool_once_attr 'innermap'
> return 0
> ;;
> esac
> diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
> index e0c650d91784..7d8ce903a471 100644
> --- a/tools/bpf/bpftool/map.c
> +++ b/tools/bpf/bpftool/map.c
> @@ -1151,6 +1151,9 @@ static int do_create(int argc, char **argv)
> return -1;
> }
> NEXT_ARG();
> + } else if (is_prefix(*argv, "innermap")) {
> + NEXT_ARG();
> + attr.inner_map_fd = map_parse_fd(&argc, &argv);
> }
> }
>
> @@ -1231,7 +1234,7 @@ static int do_help(int argc, char **argv)
> "Usage: %s %s { show | list } [MAP]\n"
> " %s %s create FILE type TYPE key KEY_SIZE value VALUE_SIZE \\\n"
> " entries MAX_ENTRIES name NAME [flags FLAGS] \\\n"
> - " [dev NAME]\n"
> + " [dev NAME] [innermap MAP]\n"
> " %s %s dump MAP\n"
> " %s %s update MAP [key DATA] [value VALUE] [UPDATE_FLAGS]\n"
> " %s %s lookup MAP [key DATA]\n"
>