Refactor cgroup attach/detach code to abstract away common operations
performed on all types of cgroup storages. This makes high-level logic more
apparent, plus allows to reuse more code across multiple functions.
Signed-off-by: Andrii Nakryiko <andriin@xxxxxx>
---
kernel/bpf/cgroup.c | 118 +++++++++++++++++++++++++++-----------------
1 file changed, 72 insertions(+), 46 deletions(-)
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 9a500fadbef5..9c8472823a7f 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -28,6 +28,58 @@ void cgroup_bpf_offline(struct cgroup *cgrp)
percpu_ref_kill(&cgrp->bpf.refcnt);
}
+static void bpf_cgroup_storages_free(struct bpf_cgroup_storage *storages[])
+{
+ enum bpf_cgroup_storage_type stype;
+
+ for_each_cgroup_storage_type(stype)
+ bpf_cgroup_storage_free(storages[stype]);
+}
+
+static int bpf_cgroup_storages_alloc(struct bpf_cgroup_storage *storages[],
+ struct bpf_prog *prog)
+{
+ enum bpf_cgroup_storage_type stype;
+
+ for_each_cgroup_storage_type(stype) {
+ storages[stype] = bpf_cgroup_storage_alloc(prog, stype);
+ if (IS_ERR(storages[stype])) {
+ storages[stype] = NULL;
+ bpf_cgroup_storages_free(storages);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+
+static void bpf_cgroup_storages_assign(struct bpf_cgroup_storage *dst[],
+ struct bpf_cgroup_storage *src[])
+{
+ enum bpf_cgroup_storage_type stype;
+
+ for_each_cgroup_storage_type(stype)
+ dst[stype] = src[stype];
+}
+
+static void bpf_cgroup_storages_link(struct bpf_cgroup_storage *storages[],
+ struct cgroup* cgrp,
+ enum bpf_attach_type attach_type)
+{
+ enum bpf_cgroup_storage_type stype;
+
+ for_each_cgroup_storage_type(stype)
+ bpf_cgroup_storage_link(storages[stype], cgrp, attach_type);
+}
+
+static void bpf_cgroup_storages_unlink(struct bpf_cgroup_storage *storages[])
+{
+ enum bpf_cgroup_storage_type stype;
+
+ for_each_cgroup_storage_type(stype)
+ bpf_cgroup_storage_unlink(storages[stype]);
+}
+
/**
* cgroup_bpf_release() - put references of all bpf programs and
* release all cgroup bpf data
@@ -37,7 +89,6 @@ static void cgroup_bpf_release(struct work_struct *work)
{
struct cgroup *p, *cgrp = container_of(work, struct cgroup,
bpf.release_work);
- enum bpf_cgroup_storage_type stype;
struct bpf_prog_array *old_array;
unsigned int type;
@@ -50,10 +101,8 @@ static void cgroup_bpf_release(struct work_struct *work)
list_for_each_entry_safe(pl, tmp, progs, node) {
list_del(&pl->node);
bpf_prog_put(pl->prog);
- for_each_cgroup_storage_type(stype) {
- bpf_cgroup_storage_unlink(pl->storage[stype]);
- bpf_cgroup_storage_free(pl->storage[stype]);
- }
+ bpf_cgroup_storages_unlink(pl->storage);
+ bpf_cgroup_storages_free(pl->storage);
kfree(pl);
static_branch_dec(&cgroup_bpf_enabled_key);
}
@@ -138,7 +187,7 @@ static int compute_effective_progs(struct cgroup *cgrp,
enum bpf_attach_type type,
struct bpf_prog_array **array)
{
- enum bpf_cgroup_storage_type stype;
+ struct bpf_prog_array_item *item;
struct bpf_prog_array *progs;
struct bpf_prog_list *pl;
struct cgroup *p = cgrp;
@@ -166,10 +215,10 @@ static int compute_effective_progs(struct cgroup *cgrp,
if (!pl->prog)
continue;
- progs->items[cnt].prog = pl->prog;
- for_each_cgroup_storage_type(stype)
- progs->items[cnt].cgroup_storage[stype] =
- pl->storage[stype];
+ item = &progs->items[cnt];
+ item->prog = pl->prog;
+ bpf_cgroup_storages_assign(item->cgroup_storage,
+ pl->storage);
cnt++;
}
} while ((p = cgroup_parent(p)));
@@ -305,7 +354,6 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE],
*old_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {NULL};
struct bpf_prog_list *pl, *replace_pl = NULL;
- enum bpf_cgroup_storage_type stype;
int err;
if (((flags & BPF_F_ALLOW_OVERRIDE) && (flags & BPF_F_ALLOW_MULTI)) ||
@@ -341,37 +389,25 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
replace_pl = list_first_entry(progs, typeof(*pl), node);
}
- for_each_cgroup_storage_type(stype) {
- storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
- if (IS_ERR(storage[stype])) {
- storage[stype] = NULL;
- for_each_cgroup_storage_type(stype)
- bpf_cgroup_storage_free(storage[stype]);
- return -ENOMEM;
- }
- }
+ if (bpf_cgroup_storages_alloc(storage, prog))
+ return -ENOMEM;
if (replace_pl) {
pl = replace_pl;
old_prog = pl->prog;
- for_each_cgroup_storage_type(stype) {
- old_storage[stype] = pl->storage[stype];
- bpf_cgroup_storage_unlink(old_storage[stype]);
- }
+ bpf_cgroup_storages_unlink(pl->storage);
+ bpf_cgroup_storages_assign(old_storage, pl->storage);
} else {
pl = kmalloc(sizeof(*pl), GFP_KERNEL);
if (!pl) {
- for_each_cgroup_storage_type(stype)
- bpf_cgroup_storage_free(storage[stype]);
+ bpf_cgroup_storages_free(storage);
return -ENOMEM;
}
list_add_tail(&pl->node, progs);
}
pl->prog = prog;
- for_each_cgroup_storage_type(stype)
- pl->storage[stype] = storage[stype];
-
+ bpf_cgroup_storages_assign(pl->storage, storage);
cgrp->bpf.flags[type] = saved_flags;
err = update_effective_progs(cgrp, type);
@@ -379,27 +415,20 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
goto cleanup;
static_branch_inc(&cgroup_bpf_enabled_key);
- for_each_cgroup_storage_type(stype) {
- if (!old_storage[stype])
- continue;
- bpf_cgroup_storage_free(old_storage[stype]);
- }
+ bpf_cgroup_storages_free(old_storage);
if (old_prog) {
bpf_prog_put(old_prog);
static_branch_dec(&cgroup_bpf_enabled_key);
}
- for_each_cgroup_storage_type(stype)
- bpf_cgroup_storage_link(storage[stype], cgrp, type);
+ bpf_cgroup_storages_link(storage, cgrp, type);
return 0;
cleanup:
/* and cleanup the prog list */
pl->prog = old_prog;
- for_each_cgroup_storage_type(stype) {
- bpf_cgroup_storage_free(pl->storage[stype]);
- pl->storage[stype] = old_storage[stype];
- bpf_cgroup_storage_link(old_storage[stype], cgrp, type);
- }
+ bpf_cgroup_storages_free(pl->storage);
+ bpf_cgroup_storages_assign(pl->storage, old_storage);
+ bpf_cgroup_storages_link(pl->storage, cgrp, type);
if (!replace_pl) {
list_del(&pl->node);
kfree(pl);
@@ -420,7 +449,6 @@ int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
enum bpf_attach_type type)
{
struct list_head *progs = &cgrp->bpf.progs[type];
- enum bpf_cgroup_storage_type stype;
u32 flags = cgrp->bpf.flags[type];
struct bpf_prog *old_prog = NULL;
struct bpf_prog_list *pl;
@@ -467,10 +495,8 @@ int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
/* now can actually delete it from this cgroup list */
list_del(&pl->node);
- for_each_cgroup_storage_type(stype) {
- bpf_cgroup_storage_unlink(pl->storage[stype]);
- bpf_cgroup_storage_free(pl->storage[stype]);
- }
+ bpf_cgroup_storages_unlink(pl->storage);
+ bpf_cgroup_storages_free(pl->storage);
kfree(pl);
if (list_empty(progs))
/* last program was detached, reset flags to zero */
--
2.17.1
