Re: [bpf-next v6 2/3] bpftool: Update doc (add autoattach to prog load)

[wangyufen]

在 2022/9/27 0:20, Daniel Borkmann 写道:
> On 9/24/22 12:13 PM, Wang Yufen wrote:
> > Add autoattach optional to prog load|loadall for supporting
> > one-step load-attach-pin_link.
> >
> > Signed-off-by: Wang Yufen <wangyufen@xxxxxxxxxx>
> > ---
> >   tools/bpf/bpftool/Documentation/bpftool-prog.rst | 13 +++++++++++--
> >   1 file changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst 
> > b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
> > index eb1b2a254eb1..2d9f27a0120f 100644
> > --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
> > +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
> > @@ -31,7 +31,7 @@ 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*] [**pinmaps** *MAP_DIR*]
> > +|    **bpftool** **prog** { **load** | **loadall** } *OBJ* *PATH* 
> > [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] 
> > [**dev** *NAME*] [**pinmaps** *MAP_DIR*] [**autoattach**]
> >   |    **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*]
> >   |    **bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*]
> >   |    **bpftool** **prog tracelog**
> > @@ -131,7 +131,7 @@ DESCRIPTION
> >             contain a dot character ('.'), which is reserved for future
> >             extensions of *bpffs*.
> >   -    **bpftool prog { load | loadall }** *OBJ* *PATH* [**type** 
> > *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** 
> > *NAME*] [**pinmaps** *MAP_DIR*]
> > +    **bpftool prog { load | loadall }** *OBJ* *PATH* [**type** 
> > *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** 
> > *NAME*] [**pinmaps** *MAP_DIR*] [**autoattach**]
> >             Load bpf program(s) from binary *OBJ* and pin as *PATH*.
> >             **bpftool prog load** pins only the first program from the
> >             *OBJ* as *PATH*. **bpftool prog loadall** pins all programs
> > @@ -150,6 +150,15 @@ DESCRIPTION
> >             Optional **pinmaps** argument can be provided to pin all
> >             maps under *MAP_DIR* directory.
> >   +          If **autoattach** is specified program will be attached
> > +          before pin. In that case, only the link (representing the
> > +          program attached to its hook) is pinned, not the program as
> > +          such, so the path won't show in "**bpftool prog show -f**",
> > +          only show in "**bpftool link show -f**". Also, this only 
> > works
> > +          when bpftool (libbpf) is able to infer all necessary 
> > information
> > +          from the objectfile, in particular, it's not supported for 
> > all
> > +          program types.
>
> Related to Quentin's comment, the documentation should also describe 
> clear semantics
> on what happens in failure case. I presume the use case you have in 
> mind is to use
> this facility for scripts e.g. to run/load some tests objs? Thus would 
> be good to describe
> to users what they need to do/clean up when things only partially 
> succeed etc..


Thanks for your comment.
add in v7, please check.

> >             Note: *PATH* must be located in *bpffs* mount. It must not
> >             contain a dot character ('.'), which is reserved for future
> >             extensions of *bpffs*.