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authorToke Høiland-Jørgensen <toke@redhat.com>2019-11-02 12:09:38 +0100
committerAlexei Starovoitov <ast@kernel.org>2019-11-02 12:35:07 -0700
commit4580b25fcee5347327aaffcec31c615ec28a889a (patch)
tree71cf7bd577f474ac8f27980028e991c0440161dd /tools/lib
parentd1b4574a4b86565325ef2e545eda8dfc9aa07c60 (diff)
downloadlinux-4580b25fcee5347327aaffcec31c615ec28a889a.tar.bz2
libbpf: Store map pin path and status in struct bpf_map
Support storing and setting a pin path in struct bpf_map, which can be used for automatic pinning. Also store the pin status so we can avoid attempts to re-pin a map that has already been pinned (or reused from a previous pinning). The behaviour of bpf_object__{un,}pin_maps() is changed so that if it is called with a NULL path argument (which was previously illegal), it will (un)pin only those maps that have a pin_path set. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/157269297876.394725.14782206533681896279.stgit@toke.dk
Diffstat (limited to 'tools/lib')
-rw-r--r--tools/lib/bpf/libbpf.c164
-rw-r--r--tools/lib/bpf/libbpf.h8
-rw-r--r--tools/lib/bpf/libbpf.map3
3 files changed, 134 insertions, 41 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 36152c8729ea..22f6dd18de6f 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -227,6 +227,8 @@ struct bpf_map {
void *priv;
bpf_map_clear_priv_t clear_priv;
enum libbpf_map_type libbpf_type;
+ char *pin_path;
+ bool pinned;
};
struct bpf_secdata {
@@ -4036,47 +4038,119 @@ int bpf_map__pin(struct bpf_map *map, const char *path)
char *cp, errmsg[STRERR_BUFSIZE];
int err;
- err = check_path(path);
- if (err)
- return err;
-
if (map == NULL) {
pr_warn("invalid map pointer\n");
return -EINVAL;
}
- if (bpf_obj_pin(map->fd, path)) {
- cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
- pr_warn("failed to pin map: %s\n", cp);
- return -errno;
+ if (map->pin_path) {
+ if (path && strcmp(path, map->pin_path)) {
+ pr_warn("map '%s' already has pin path '%s' different from '%s'\n",
+ bpf_map__name(map), map->pin_path, path);
+ return -EINVAL;
+ } else if (map->pinned) {
+ pr_debug("map '%s' already pinned at '%s'; not re-pinning\n",
+ bpf_map__name(map), map->pin_path);
+ return 0;
+ }
+ } else {
+ if (!path) {
+ pr_warn("missing a path to pin map '%s' at\n",
+ bpf_map__name(map));
+ return -EINVAL;
+ } else if (map->pinned) {
+ pr_warn("map '%s' already pinned\n", bpf_map__name(map));
+ return -EEXIST;
+ }
+
+ map->pin_path = strdup(path);
+ if (!map->pin_path) {
+ err = -errno;
+ goto out_err;
+ }
}
- pr_debug("pinned map '%s'\n", path);
+ err = check_path(map->pin_path);
+ if (err)
+ return err;
+
+ if (bpf_obj_pin(map->fd, map->pin_path)) {
+ err = -errno;
+ goto out_err;
+ }
+
+ map->pinned = true;
+ pr_debug("pinned map '%s'\n", map->pin_path);
return 0;
+
+out_err:
+ cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg));
+ pr_warn("failed to pin map: %s\n", cp);
+ return err;
}
int bpf_map__unpin(struct bpf_map *map, const char *path)
{
int err;
- err = check_path(path);
- if (err)
- return err;
-
if (map == NULL) {
pr_warn("invalid map pointer\n");
return -EINVAL;
}
+ if (map->pin_path) {
+ if (path && strcmp(path, map->pin_path)) {
+ pr_warn("map '%s' already has pin path '%s' different from '%s'\n",
+ bpf_map__name(map), map->pin_path, path);
+ return -EINVAL;
+ }
+ path = map->pin_path;
+ } else if (!path) {
+ pr_warn("no path to unpin map '%s' from\n",
+ bpf_map__name(map));
+ return -EINVAL;
+ }
+
+ err = check_path(path);
+ if (err)
+ return err;
+
err = unlink(path);
if (err != 0)
return -errno;
- pr_debug("unpinned map '%s'\n", path);
+
+ map->pinned = false;
+ pr_debug("unpinned map '%s' from '%s'\n", bpf_map__name(map), path);
return 0;
}
+int bpf_map__set_pin_path(struct bpf_map *map, const char *path)
+{
+ char *new = NULL;
+
+ if (path) {
+ new = strdup(path);
+ if (!new)
+ return -errno;
+ }
+
+ free(map->pin_path);
+ map->pin_path = new;
+ return 0;
+}
+
+const char *bpf_map__get_pin_path(const struct bpf_map *map)
+{
+ return map->pin_path;
+}
+
+bool bpf_map__is_pinned(const struct bpf_map *map)
+{
+ return map->pinned;
+}
+
int bpf_object__pin_maps(struct bpf_object *obj, const char *path)
{
struct bpf_map *map;
@@ -4095,20 +4169,27 @@ int bpf_object__pin_maps(struct bpf_object *obj, const char *path)
return err;
bpf_object__for_each_map(map, obj) {
+ char *pin_path = NULL;
char buf[PATH_MAX];
- int len;
- len = snprintf(buf, PATH_MAX, "%s/%s", path,
- bpf_map__name(map));
- if (len < 0) {
- err = -EINVAL;
- goto err_unpin_maps;
- } else if (len >= PATH_MAX) {
- err = -ENAMETOOLONG;
- goto err_unpin_maps;
+ if (path) {
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ bpf_map__name(map));
+ if (len < 0) {
+ err = -EINVAL;
+ goto err_unpin_maps;
+ } else if (len >= PATH_MAX) {
+ err = -ENAMETOOLONG;
+ goto err_unpin_maps;
+ }
+ pin_path = buf;
+ } else if (!map->pin_path) {
+ continue;
}
- err = bpf_map__pin(map, buf);
+ err = bpf_map__pin(map, pin_path);
if (err)
goto err_unpin_maps;
}
@@ -4117,17 +4198,10 @@ int bpf_object__pin_maps(struct bpf_object *obj, const char *path)
err_unpin_maps:
while ((map = bpf_map__prev(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)
+ if (!map->pin_path)
continue;
- bpf_map__unpin(map, buf);
+ bpf_map__unpin(map, NULL);
}
return err;
@@ -4142,17 +4216,24 @@ int bpf_object__unpin_maps(struct bpf_object *obj, const char *path)
return -ENOENT;
bpf_object__for_each_map(map, obj) {
+ char *pin_path = NULL;
char buf[PATH_MAX];
- int len;
- 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 (path) {
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ bpf_map__name(map));
+ if (len < 0)
+ return -EINVAL;
+ else if (len >= PATH_MAX)
+ return -ENAMETOOLONG;
+ pin_path = buf;
+ } else if (!map->pin_path) {
+ continue;
+ }
- err = bpf_map__unpin(map, buf);
+ err = bpf_map__unpin(map, pin_path);
if (err)
return err;
}
@@ -4277,6 +4358,7 @@ void bpf_object__close(struct bpf_object *obj)
for (i = 0; i < obj->nr_maps; i++) {
zfree(&obj->maps[i].name);
+ zfree(&obj->maps[i].pin_path);
if (obj->maps[i].clear_priv)
obj->maps[i].clear_priv(&obj->maps[i],
obj->maps[i].priv);
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 2b126ee5e173..e71773a6bfdf 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -124,6 +124,11 @@ int bpf_object__section_size(const struct bpf_object *obj, const char *name,
__u32 *size);
int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
__u32 *off);
+
+/* pin_maps and unpin_maps can both be called with a NULL path, in which case
+ * they will use the pin_path attribute of each map (and ignore all maps that
+ * don't have a pin_path set).
+ */
LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
const char *path);
@@ -387,6 +392,9 @@ LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries);
LIBBPF_API bool bpf_map__is_offload_neutral(const struct bpf_map *map);
LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
+LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
+LIBBPF_API const char *bpf_map__get_pin_path(const struct bpf_map *map);
+LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 69dded5af00b..86173cbb159d 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -193,6 +193,9 @@ LIBBPF_0.0.5 {
LIBBPF_0.0.6 {
global:
+ bpf_map__get_pin_path;
+ bpf_map__is_pinned;
+ bpf_map__set_pin_path;
bpf_object__open_file;
bpf_object__open_mem;
bpf_program__get_expected_attach_type;