| Message ID | 20200729230520.693207-6-andriin@fb.com |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | BPF link force-detach support | expand |
> On Jul 29, 2020, at 4:05 PM, Andrii Nakryiko <andriin@fb.com> wrote: > > Add info on link detach sub-command to man page. Add detach to bash-completion > as well. > > Signed-off-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Song Liu <songliubraving@fb.com> With one nitpick below. > --- [...] > @@ -49,6 +50,13 @@ DESCRIPTION > contain a dot character ('.'), which is reserved for future > extensions of *bpffs*. > > + **bpftool link detach** *LINK* > + Force-detach link *LINK*. BPF link and its underlying BPF > + program will stay valid, but they will be detached from the > + respective BPF hook and BPF link will transition into > + a defunct state until last open file descriptor for that Shall we say "a defunct state when the last open file descriptor for that..."? > + link is closed. > + > **bpftool link help** > Print short help message. > [...]
On Thu, Jul 30, 2020 at 2:13 PM Song Liu <songliubraving@fb.com> wrote: > > > > > On Jul 29, 2020, at 4:05 PM, Andrii Nakryiko <andriin@fb.com> wrote: > > > > Add info on link detach sub-command to man page. Add detach to bash-completion > > as well. > > > > Signed-off-by: Andrii Nakryiko <andriin@fb.com> > > Acked-by: Song Liu <songliubraving@fb.com> > > With one nitpick below. > > > --- > > [...] > > > @@ -49,6 +50,13 @@ DESCRIPTION > > contain a dot character ('.'), which is reserved for future > > extensions of *bpffs*. > > > > + **bpftool link detach** *LINK* > > + Force-detach link *LINK*. BPF link and its underlying BPF > > + program will stay valid, but they will be detached from the > > + respective BPF hook and BPF link will transition into > > + a defunct state until last open file descriptor for that > > Shall we say "a defunct state when the last open file descriptor for that..."? No-no, it is in defunc state between LINK_DETACH and last FD being closed. Once last FD is closed, BPF link will get destructed and freed in kernel. So I think until is more precise here? > > > > + link is closed. > > + > > **bpftool link help** > > Print short help message. > > > > [...]
> On Jul 30, 2020, at 2:16 PM, Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote: > > On Thu, Jul 30, 2020 at 2:13 PM Song Liu <songliubraving@fb.com> wrote: >> >> >> >>> On Jul 29, 2020, at 4:05 PM, Andrii Nakryiko <andriin@fb.com> wrote: >>> >>> Add info on link detach sub-command to man page. Add detach to bash-completion >>> as well. >>> >>> Signed-off-by: Andrii Nakryiko <andriin@fb.com> >> >> Acked-by: Song Liu <songliubraving@fb.com> >> >> With one nitpick below. >> >>> --- >> >> [...] >> >>> @@ -49,6 +50,13 @@ DESCRIPTION >>> contain a dot character ('.'), which is reserved for future >>> extensions of *bpffs*. >>> >>> + **bpftool link detach** *LINK* >>> + Force-detach link *LINK*. BPF link and its underlying BPF >>> + program will stay valid, but they will be detached from the >>> + respective BPF hook and BPF link will transition into >>> + a defunct state until last open file descriptor for that >> >> Shall we say "a defunct state when the last open file descriptor for that..."? > > > No-no, it is in defunc state between LINK_DETACH and last FD being > closed. Once last FD is closed, BPF link will get destructed and freed > in kernel. So I think until is more precise here? Ah, I see. I misunderstood "defunct state". Please ignore the comment. Thanks, Song
diff --git a/tools/bpf/bpftool/Documentation/bpftool-link.rst b/tools/bpf/bpftool/Documentation/bpftool-link.rst index 38b0949a185b..4a52e7a93339 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-link.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-link.rst @@ -21,6 +21,7 @@ LINK COMMANDS | **bpftool** **link { show | list }** [*LINK*] | **bpftool** **link pin** *LINK* *FILE* +| **bpftool** **link detach *LINK* | **bpftool** **link help** | | *LINK* := { **id** *LINK_ID* | **pinned** *FILE* } @@ -49,6 +50,13 @@ DESCRIPTION contain a dot character ('.'), which is reserved for future extensions of *bpffs*. + **bpftool link detach** *LINK* + Force-detach link *LINK*. BPF link and its underlying BPF + program will stay valid, but they will be detached from the + respective BPF hook and BPF link will transition into + a defunct state until last open file descriptor for that + link is closed. + **bpftool link help** Print short help message. diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index 257fa310ea2b..f53ed2f1a4aa 100644 --- a/tools/bpf/bpftool/bash-completion/bpftool +++ b/tools/bpf/bpftool/bash-completion/bpftool @@ -1122,7 +1122,7 @@ _bpftool() ;; link) case $command in - show|list|pin) + show|list|pin|detach) case $prev in id) _bpftool_get_link_ids @@ -1139,7 +1139,7 @@ _bpftool() COMPREPLY=( $( compgen -W "$LINK_TYPE" -- "$cur" ) ) return 0 ;; - pin) + pin|detach) if [[ $prev == "$command" ]]; then COMPREPLY=( $( compgen -W "$LINK_TYPE" -- "$cur" ) ) else
Add info on link detach sub-command to man page. Add detach to bash-completion as well. Signed-off-by: Andrii Nakryiko <andriin@fb.com> --- tools/bpf/bpftool/Documentation/bpftool-link.rst | 8 ++++++++ tools/bpf/bpftool/bash-completion/bpftool | 4 ++-- 2 files changed, 10 insertions(+), 2 deletions(-)