From: KP Singh <kpsi...@google.com> Provide the a ability to define local storage caches on a per-object type basis. The caches and caching indices for different objects should not be inter-mixed as suggested in:
https://lore.kernel.org/bpf/20200630193441.kdwnkestulg5e...@kafai-mbp.dhcp.thefacebook.com/ "Caching a sk-storage at idx=0 of a sk should not stop an inode-storage to be cached at the same idx of a inode." Signed-off-by: KP Singh <kpsi...@google.com> --- include/net/bpf_sk_storage.h | 19 +++++++++++++++++++ net/core/bpf_sk_storage.c | 31 +++++++++++++++---------------- 2 files changed, 34 insertions(+), 16 deletions(-) diff --git a/include/net/bpf_sk_storage.h b/include/net/bpf_sk_storage.h index 5036c94c0503..950c5aaba15e 100644 --- a/include/net/bpf_sk_storage.h +++ b/include/net/bpf_sk_storage.h @@ -3,6 +3,9 @@ #ifndef _BPF_SK_STORAGE_H #define _BPF_SK_STORAGE_H +#include <linux/types.h> +#include <linux/spinlock.h> + struct sock; void bpf_sk_storage_free(struct sock *sk); @@ -15,6 +18,22 @@ struct sk_buff; struct nlattr; struct sock; +#define BPF_LOCAL_STORAGE_CACHE_SIZE 16 + +struct bpf_local_storage_cache { + spinlock_t idx_lock; + u64 idx_usage_counts[BPF_LOCAL_STORAGE_CACHE_SIZE]; +}; + +#define DEFINE_BPF_STORAGE_CACHE(name) \ +static struct bpf_local_storage_cache name = { \ + .idx_lock = __SPIN_LOCK_UNLOCKED(name.idx_lock), \ +} + +u16 bpf_local_storage_cache_idx_get(struct bpf_local_storage_cache *cache); +void bpf_local_storage_cache_idx_free(struct bpf_local_storage_cache *cache, + u16 idx); + #ifdef CONFIG_BPF_SYSCALL int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk); struct bpf_sk_storage_diag * diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c index a5cc218834ee..99dde7b74767 100644 --- a/net/core/bpf_sk_storage.c +++ b/net/core/bpf_sk_storage.c @@ -14,6 +14,8 @@ #define BPF_LOCAL_STORAGE_CREATE_FLAG_MASK (BPF_F_NO_PREALLOC | BPF_F_CLONE) +DEFINE_BPF_STORAGE_CACHE(sk_cache); + struct bpf_local_storage_map_bucket { struct hlist_head list; raw_spinlock_t lock; @@ -78,10 +80,6 @@ struct bpf_local_storage_elem { #define SELEM(_SDATA) \ container_of((_SDATA), struct bpf_local_storage_elem, sdata) #define SDATA(_SELEM) (&(_SELEM)->sdata) -#define BPF_LOCAL_STORAGE_CACHE_SIZE 16 - -static DEFINE_SPINLOCK(cache_idx_lock); -static u64 cache_idx_usage_counts[BPF_LOCAL_STORAGE_CACHE_SIZE]; struct bpf_local_storage { struct bpf_local_storage_data __rcu *cache[BPF_LOCAL_STORAGE_CACHE_SIZE]; @@ -517,16 +515,16 @@ static int sk_storage_delete(struct sock *sk, struct bpf_map *map) return 0; } -static u16 cache_idx_get(void) +u16 bpf_local_storage_cache_idx_get(struct bpf_local_storage_cache *cache) { u64 min_usage = U64_MAX; u16 i, res = 0; - spin_lock(&cache_idx_lock); + spin_lock(&cache->idx_lock); for (i = 0; i < BPF_LOCAL_STORAGE_CACHE_SIZE; i++) { - if (cache_idx_usage_counts[i] < min_usage) { - min_usage = cache_idx_usage_counts[i]; + if (cache->idx_usage_counts[i] < min_usage) { + min_usage = cache->idx_usage_counts[i]; res = i; /* Found a free cache_idx */ @@ -534,18 +532,19 @@ static u16 cache_idx_get(void) break; } } - cache_idx_usage_counts[res]++; + cache->idx_usage_counts[res]++; - spin_unlock(&cache_idx_lock); + spin_unlock(&cache->idx_lock); return res; } -static void cache_idx_free(u16 idx) +void bpf_local_storage_cache_idx_free(struct bpf_local_storage_cache *cache, + u16 idx) { - spin_lock(&cache_idx_lock); - cache_idx_usage_counts[idx]--; - spin_unlock(&cache_idx_lock); + spin_lock(&cache->idx_lock); + cache->idx_usage_counts[idx]--; + spin_unlock(&cache->idx_lock); } /* Called by __sk_destruct() & bpf_sk_storage_clone() */ @@ -597,7 +596,7 @@ static void bpf_local_storage_map_free(struct bpf_map *map) smap = (struct bpf_local_storage_map *)map; - cache_idx_free(smap->cache_idx); + bpf_local_storage_cache_idx_free(&sk_cache, smap->cache_idx); /* Note that this map might be concurrently cloned from * bpf_sk_storage_clone. Wait for any existing bpf_sk_storage_clone @@ -713,7 +712,7 @@ static struct bpf_map *bpf_local_storage_map_alloc(union bpf_attr *attr) } smap->elem_size = sizeof(struct bpf_local_storage_elem) + attr->value_size; - smap->cache_idx = cache_idx_get(); + smap->cache_idx = bpf_local_storage_cache_idx_get(&sk_cache); return &smap->map; } -- 2.28.0.163.g6104cc2f0b6-goog
