From: Takshak Chahande <ctakshak@fb.com>
Date: Tue, 10 May 2022 01:22:20 -0700
Subject: bpf: Extend batch operations for map-in-map bpf-maps
Patch-mainline: v5.19-rc1
Git-commit: 9263dddc7b6f816fdd327eee435cc54ba51dd095
References: jsc#PED-1377
This patch extends batch operations support for map-in-map map-types:
BPF_MAP_TYPE_HASH_OF_MAPS and BPF_MAP_TYPE_ARRAY_OF_MAPS
A usecase where outer HASH map holds hundred of VIP entries and its
associated reuse-ports per VIP stored in REUSEPORT_SOCKARRAY type
inner map, needs to do batch operation for performance gain.
This patch leverages the exiting generic functions for most of the batch
operations. As map-in-map's value contains the actual reference of the inner map,
for BPF_MAP_TYPE_HASH_OF_MAPS type, it needed an extra step to fetch the
map_id from the reference value.
selftests are added in next patch 2/2.
Signed-off-by: Takshak Chahande <ctakshak@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220510082221.2390540-1-ctakshak@fb.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
kernel/bpf/arraymap.c | 2 ++
kernel/bpf/hashtab.c | 13 +++++++++++--
2 files changed, 13 insertions(+), 2 deletions(-)
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -1345,6 +1345,8 @@ const struct bpf_map_ops array_of_maps_m
.map_fd_put_ptr = bpf_map_fd_put_ptr,
.map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
.map_gen_lookup = array_of_map_gen_lookup,
+ .map_lookup_batch = generic_map_lookup_batch,
+ .map_update_batch = generic_map_update_batch,
.map_check_btf = map_check_no_btf,
.map_btf_id = &array_map_btf_ids[0],
};
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -140,7 +140,7 @@ static inline bool htab_use_raw_lock(con
static void htab_init_buckets(struct bpf_htab *htab)
{
- unsigned i;
+ unsigned int i;
for (i = 0; i < htab->n_buckets; i++) {
INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i);
@@ -1627,7 +1627,7 @@ __htab_map_lookup_and_delete_batch(struc
void __user *uvalues = u64_to_user_ptr(attr->batch.values);
void __user *ukeys = u64_to_user_ptr(attr->batch.keys);
void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
- u32 batch, max_count, size, bucket_size;
+ u32 batch, max_count, size, bucket_size, map_id;
struct htab_elem *node_to_free = NULL;
u64 elem_map_flags, map_flags;
struct hlist_nulls_head *head;
@@ -1752,6 +1752,14 @@ again_nocopy:
}
} else {
value = l->key + roundup_key_size;
+ if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
+ struct bpf_map **inner_map = value;
+
+ /* Actual value is the id of the inner map */
+ map_id = map->ops->map_fd_sys_lookup_elem(*inner_map);
+ value = &map_id;
+ }
+
if (elem_map_flags & BPF_F_LOCK)
copy_map_value_locked(map, dst_val, value,
true);
@@ -2450,5 +2458,6 @@ const struct bpf_map_ops htab_of_maps_ma
.map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
.map_gen_lookup = htab_of_map_gen_lookup,
.map_check_btf = map_check_no_btf,
+ BATCH_OPS(htab),
.map_btf_id = &htab_map_btf_ids[0],
};