On 11/07, Jakub Kicinski wrote:
On Wed, 7 Nov 2018 14:43:55 -0800, Stanislav Fomichev wrote:
bpftool will use bpf_object__pin in the next commit to pin all programs and maps from the file; in case of a partial failure, we need to get back to the clean state (undo previous program/map pins).
Signed-off-by: Stanislav Fomichev sdf@google.com
tools/lib/bpf/libbpf.c | 58 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 48 insertions(+), 10 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index d6e62e90e8d4..309abe7196f3 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1803,14 +1803,17 @@ int bpf_object__pin(struct bpf_object *obj, const char *path) len = snprintf(buf, PATH_MAX, "%s/%s", path, bpf_map__name(map));
if (len < 0)return -EINVAL;else if (len >= PATH_MAX)return -ENAMETOOLONG;
if (len < 0) {err = -EINVAL;goto err_unpin_maps;} else if (len >= PATH_MAX) {err = -ENAMETOOLONG;goto err_unpin_maps;}err = bpf_map__pin(map, buf); if (err)
return err;
goto err_unpin_maps;bpf_object__for_each_program(prog, obj) { @@ -1819,17 +1822,52 @@ int bpf_object__pin(struct bpf_object *obj, const char *path) len = snprintf(buf, PATH_MAX, "%s/%s", path, prog->section_name);
if (len < 0)return -EINVAL;else if (len >= PATH_MAX)return -ENAMETOOLONG;
if (len < 0) {err = -EINVAL;goto err_unpin_programs;} else if (len >= PATH_MAX) {err = -ENAMETOOLONG;goto err_unpin_programs;}err = bpf_program__pin(prog, buf); if (err)
return err;
goto err_unpin_programs;return 0;
+err_unpin_programs:
- bpf_object__for_each_program(prog, obj) {
char buf[PATH_MAX];int len;len = snprintf(buf, PATH_MAX, "%s/%s", path,prog->section_name);if (len < 0)continue;else if (len >= PATH_MAX)continue;unlink(buf);I think that's no bueno, if pin failed because the file already exists you'll now remove that already existing file.
How about we check beforehand and bail early if we are going to overwrite something?
- }
+err_unpin_maps:
- bpf_map__for_each(map, obj) {
char buf[PATH_MAX];int len;len = snprintf(buf, PATH_MAX, "%s/%s", path,bpf_map__name(map));if (len < 0)continue;else if (len >= PATH_MAX)continue;unlink(buf);- }
- return err;
} void bpf_object__close(struct bpf_object *obj)