Re: [PATCH bpf-next 3/5] bpf: group memory related fields in struct bpf_map_memory

From: Song Liu
Date: Thu May 30 2019 - 14:57:08 EST


On Wed, May 29, 2019 at 6:04 PM Roman Gushchin <guro@xxxxxx> wrote:
>
> Group "user" and "pages" fields of bpf_map into the bpf_map_memory
> structure. Later it can be extended with "memcg" and other related
> information.
>
> The main reason for a such change (beside cosmetics) is to pass
> bpf_map_memory structure to charging functions before the actual
> allocation of bpf_map.
>
> Signed-off-by: Roman Gushchin <guro@xxxxxx>

Acked-by: Song Liu <songliubraving@xxxxxx>

> ---
> include/linux/bpf.h | 10 +++++++---
> kernel/bpf/arraymap.c | 2 +-
> kernel/bpf/cpumap.c | 4 ++--
> kernel/bpf/devmap.c | 4 ++--
> kernel/bpf/hashtab.c | 4 ++--
> kernel/bpf/local_storage.c | 2 +-
> kernel/bpf/lpm_trie.c | 4 ++--
> kernel/bpf/queue_stack_maps.c | 2 +-
> kernel/bpf/reuseport_array.c | 2 +-
> kernel/bpf/stackmap.c | 4 ++--
> kernel/bpf/syscall.c | 19 ++++++++++---------
> kernel/bpf/xskmap.c | 4 ++--
> net/core/bpf_sk_storage.c | 2 +-
> net/core/sock_map.c | 4 ++--
> 14 files changed, 36 insertions(+), 31 deletions(-)
>
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index ff3e00ff84d2..980b7a9bdd21 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -66,6 +66,11 @@ struct bpf_map_ops {
> u64 imm, u32 *off);
> };
>
> +struct bpf_map_memory {
> + u32 pages;
> + struct user_struct *user;
> +};
> +
> struct bpf_map {
> /* The first two cachelines with read-mostly members of which some
> * are also accessed in fast-path (e.g. ops, max_entries).
> @@ -86,7 +91,7 @@ struct bpf_map {
> u32 btf_key_type_id;
> u32 btf_value_type_id;
> struct btf *btf;
> - u32 pages;
> + struct bpf_map_memory memory;
> bool unpriv_array;
> bool frozen; /* write-once */
> /* 48 bytes hole */
> @@ -94,8 +99,7 @@ struct bpf_map {
> /* The 3rd and 4th cacheline with misc members to avoid false sharing
> * particularly with refcounting.
> */
> - struct user_struct *user ____cacheline_aligned;
> - atomic_t refcnt;
> + atomic_t refcnt ____cacheline_aligned;
> atomic_t usercnt;
> struct work_struct work;
> char name[BPF_OBJ_NAME_LEN];
> diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
> index 584636c9e2eb..8fda24e78193 100644
> --- a/kernel/bpf/arraymap.c
> +++ b/kernel/bpf/arraymap.c
> @@ -138,7 +138,7 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr)
>
> /* copy mandatory map attributes */
> bpf_map_init_from_attr(&array->map, attr);
> - array->map.pages = cost;
> + array->map.memory.pages = cost;
> array->elem_size = elem_size;
>
> if (percpu && bpf_array_alloc_percpu(array)) {
> diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
> index cf727d77c6c6..035268add724 100644
> --- a/kernel/bpf/cpumap.c
> +++ b/kernel/bpf/cpumap.c
> @@ -108,10 +108,10 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
> cost += cpu_map_bitmap_size(attr) * num_possible_cpus();
> if (cost >= U32_MAX - PAGE_SIZE)
> goto free_cmap;
> - cmap->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
> + cmap->map.memory.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
>
> /* Notice returns -EPERM on if map size is larger than memlock limit */
> - ret = bpf_map_precharge_memlock(cmap->map.pages);
> + ret = bpf_map_precharge_memlock(cmap->map.memory.pages);
> if (ret) {
> err = ret;
> goto free_cmap;
> diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
> index 1e525d70f833..f6c57efb1d0d 100644
> --- a/kernel/bpf/devmap.c
> +++ b/kernel/bpf/devmap.c
> @@ -111,10 +111,10 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
> if (cost >= U32_MAX - PAGE_SIZE)
> goto free_dtab;
>
> - dtab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
> + dtab->map.memory.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
>
> /* if map size is larger than memlock limit, reject it early */
> - err = bpf_map_precharge_memlock(dtab->map.pages);
> + err = bpf_map_precharge_memlock(dtab->map.memory.pages);
> if (err)
> goto free_dtab;
>
> diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
> index 0f2708fde5f7..15bf228d2e98 100644
> --- a/kernel/bpf/hashtab.c
> +++ b/kernel/bpf/hashtab.c
> @@ -364,10 +364,10 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
> /* make sure page count doesn't overflow */
> goto free_htab;
>
> - htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
> + htab->map.memory.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
>
> /* if map size is larger than memlock limit, reject it early */
> - err = bpf_map_precharge_memlock(htab->map.pages);
> + err = bpf_map_precharge_memlock(htab->map.memory.pages);
> if (err)
> goto free_htab;
>
> diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
> index e48302ecb389..574325276650 100644
> --- a/kernel/bpf/local_storage.c
> +++ b/kernel/bpf/local_storage.c
> @@ -303,7 +303,7 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
> if (!map)
> return ERR_PTR(-ENOMEM);
>
> - map->map.pages = pages;
> + map->map.memory.pages = pages;
>
> /* copy mandatory map attributes */
> bpf_map_init_from_attr(&map->map, attr);
> diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
> index e61630c2e50b..8e423a582760 100644
> --- a/kernel/bpf/lpm_trie.c
> +++ b/kernel/bpf/lpm_trie.c
> @@ -578,9 +578,9 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr)
> goto out_err;
> }
>
> - trie->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
> + trie->map.memory.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
>
> - ret = bpf_map_precharge_memlock(trie->map.pages);
> + ret = bpf_map_precharge_memlock(trie->map.memory.pages);
> if (ret)
> goto out_err;
>
> diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c
> index 0b140d236889..8a510e71d486 100644
> --- a/kernel/bpf/queue_stack_maps.c
> +++ b/kernel/bpf/queue_stack_maps.c
> @@ -89,7 +89,7 @@ static struct bpf_map *queue_stack_map_alloc(union bpf_attr *attr)
>
> bpf_map_init_from_attr(&qs->map, attr);
>
> - qs->map.pages = cost;
> + qs->map.memory.pages = cost;
> qs->size = size;
>
> raw_spin_lock_init(&qs->lock);
> diff --git a/kernel/bpf/reuseport_array.c b/kernel/bpf/reuseport_array.c
> index 18e225de80ff..819515242739 100644
> --- a/kernel/bpf/reuseport_array.c
> +++ b/kernel/bpf/reuseport_array.c
> @@ -176,7 +176,7 @@ static struct bpf_map *reuseport_array_alloc(union bpf_attr *attr)
>
> /* copy mandatory map attributes */
> bpf_map_init_from_attr(&array->map, attr);
> - array->map.pages = cost;
> + array->map.memory.pages = cost;
>
> return &array->map;
> }
> diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
> index 950ab2f28922..08d4efff73ac 100644
> --- a/kernel/bpf/stackmap.c
> +++ b/kernel/bpf/stackmap.c
> @@ -131,9 +131,9 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
> bpf_map_init_from_attr(&smap->map, attr);
> smap->map.value_size = value_size;
> smap->n_buckets = n_buckets;
> - smap->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
> + smap->map.memory.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
>
> - err = bpf_map_precharge_memlock(smap->map.pages);
> + err = bpf_map_precharge_memlock(smap->map.memory.pages);
> if (err)
> goto free_smap;
>
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index 3d546b6f4646..df14e63806c8 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -222,19 +222,20 @@ static int bpf_map_init_memlock(struct bpf_map *map)
> struct user_struct *user = get_current_user();
> int ret;
>
> - ret = bpf_charge_memlock(user, map->pages);
> + ret = bpf_charge_memlock(user, map->memory.pages);
> if (ret) {
> free_uid(user);
> return ret;
> }
> - map->user = user;
> + map->memory.user = user;
> return ret;
> }
>
> static void bpf_map_release_memlock(struct bpf_map *map)
> {
> - struct user_struct *user = map->user;
> - bpf_uncharge_memlock(user, map->pages);
> + struct user_struct *user = map->memory.user;
> +
> + bpf_uncharge_memlock(user, map->memory.pages);
> free_uid(user);
> }
>
> @@ -242,17 +243,17 @@ int bpf_map_charge_memlock(struct bpf_map *map, u32 pages)
> {
> int ret;
>
> - ret = bpf_charge_memlock(map->user, pages);
> + ret = bpf_charge_memlock(map->memory.user, pages);
> if (ret)
> return ret;
> - map->pages += pages;
> + map->memory.pages += pages;
> return ret;
> }
>
> void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages)
> {
> - bpf_uncharge_memlock(map->user, pages);
> - map->pages -= pages;
> + bpf_uncharge_memlock(map->memory.user, pages);
> + map->memory.pages -= pages;
> }
>
> static int bpf_map_alloc_id(struct bpf_map *map)
> @@ -395,7 +396,7 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
> map->value_size,
> map->max_entries,
> map->map_flags,
> - map->pages * 1ULL << PAGE_SHIFT,
> + map->memory.pages * 1ULL << PAGE_SHIFT,
> map->id,
> READ_ONCE(map->frozen));
>
> diff --git a/kernel/bpf/xskmap.c b/kernel/bpf/xskmap.c
> index 686d244e798d..f816ee1a0fa0 100644
> --- a/kernel/bpf/xskmap.c
> +++ b/kernel/bpf/xskmap.c
> @@ -40,10 +40,10 @@ static struct bpf_map *xsk_map_alloc(union bpf_attr *attr)
> if (cost >= U32_MAX - PAGE_SIZE)
> goto free_m;
>
> - m->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
> + m->map.memory.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
>
> /* Notice returns -EPERM on if map size is larger than memlock limit */
> - err = bpf_map_precharge_memlock(m->map.pages);
> + err = bpf_map_precharge_memlock(m->map.memory.pages);
> if (err)
> goto free_m;
>
> diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
> index 9a8aaf8e235d..92581c3ff220 100644
> --- a/net/core/bpf_sk_storage.c
> +++ b/net/core/bpf_sk_storage.c
> @@ -659,7 +659,7 @@ static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr)
> smap->elem_size = sizeof(struct bpf_sk_storage_elem) + attr->value_size;
> smap->cache_idx = (unsigned int)atomic_inc_return(&cache_idx) %
> BPF_SK_STORAGE_CACHE_SIZE;
> - smap->map.pages = pages;
> + smap->map.memory.pages = pages;
>
> return &smap->map;
> }
> diff --git a/net/core/sock_map.c b/net/core/sock_map.c
> index be6092ac69f8..4eb5b6a1b29f 100644
> --- a/net/core/sock_map.c
> +++ b/net/core/sock_map.c
> @@ -49,8 +49,8 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
> goto free_stab;
> }
>
> - stab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
> - err = bpf_map_precharge_memlock(stab->map.pages);
> + stab->map.memory.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
> + err = bpf_map_precharge_memlock(stab->map.memory.pages);
> if (err)
> goto free_stab;
>
> --
> 2.20.1
>