[PATCH bpf-next v9 1/7] bpf: Renames in preparation for bpf_local_storage

From: KP Singh
Date: Sun Aug 23 2020 - 12:58:05 EST

From: KP Singh <kpsingh@xxxxxxxxxx>

A purely mechanical change to split the renaming from the actual
generalization.

Flags/consts:

SK_STORAGE_CREATE_FLAG_MASK BPF_LOCAL_STORAGE_CREATE_FLAG_MASK
BPF_SK_STORAGE_CACHE_SIZE BPF_LOCAL_STORAGE_CACHE_SIZE
MAX_VALUE_SIZE BPF_LOCAL_STORAGE_MAX_VALUE_SIZE

Structs:

bucket bpf_local_storage_map_bucket
bpf_sk_storage_map bpf_local_storage_map
bpf_sk_storage_data bpf_local_storage_data
bpf_sk_storage_elem bpf_local_storage_elem
bpf_sk_storage bpf_local_storage

The "sk" member in bpf_local_storage is also updated to "owner"
in preparation for changing the type to void * in a subsequent patch.

Functions:

selem_linked_to_sk selem_linked_to_storage
selem_alloc bpf_selem_alloc
__selem_unlink_sk bpf_selem_unlink_storage_nolock
__selem_link_sk bpf_selem_link_storage_nolock
selem_unlink_sk __bpf_selem_unlink_storage
sk_storage_update bpf_local_storage_update
__sk_storage_lookup bpf_local_storage_lookup
bpf_sk_storage_map_free bpf_local_storage_map_free
bpf_sk_storage_map_alloc bpf_local_storage_map_alloc
bpf_sk_storage_map_alloc_check bpf_local_storage_map_alloc_check
bpf_sk_storage_map_check_btf bpf_local_storage_map_check_btf

Acked-by: Martin KaFai Lau <kafai@xxxxxx>
Signed-off-by: KP Singh <kpsingh@xxxxxxxxxx>
---
include/net/sock.h | 4 +-
net/core/bpf_sk_storage.c | 488 +++++++++++++++++++-------------------
2 files changed, 252 insertions(+), 240 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index 064637d1ddf6..18423cc9cde8 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -246,7 +246,7 @@ struct sock_common {
/* public: */
};

-struct bpf_sk_storage;
+struct bpf_local_storage;

/**
* struct sock - network layer representation of sockets
@@ -517,7 +517,7 @@ struct sock {
void (*sk_destruct)(struct sock *sk);
struct sock_reuseport __rcu *sk_reuseport_cb;
#ifdef CONFIG_BPF_SYSCALL
- struct bpf_sk_storage __rcu *sk_bpf_storage;
+ struct bpf_local_storage __rcu *sk_bpf_storage;
#endif
struct rcu_head sk_rcu;
};
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index 281200dc0a01..f975e2d01207 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -12,33 +12,32 @@
#include <uapi/linux/sock_diag.h>
#include <uapi/linux/btf.h>

-#define SK_STORAGE_CREATE_FLAG_MASK \
- (BPF_F_NO_PREALLOC | BPF_F_CLONE)
+#define BPF_LOCAL_STORAGE_CREATE_FLAG_MASK (BPF_F_NO_PREALLOC | BPF_F_CLONE)

-struct bucket {
+struct bpf_local_storage_map_bucket {
struct hlist_head list;
raw_spinlock_t lock;
};

-/* Thp map is not the primary owner of a bpf_sk_storage_elem.
- * Instead, the sk->sk_bpf_storage is.
+/* Thp map is not the primary owner of a bpf_local_storage_elem.
+ * Instead, the container object (eg. sk->sk_bpf_storage) is.
*
- * The map (bpf_sk_storage_map) is for two purposes
- * 1. Define the size of the "sk local storage". It is
+ * The map (bpf_local_storage_map) is for two purposes
+ * 1. Define the size of the "local storage". It is
* the map's value_size.
*
* 2. Maintain a list to keep track of all elems such
* that they can be cleaned up during the map destruction.
*
* When a bpf local storage is being looked up for a
- * particular sk, the "bpf_map" pointer is actually used
+ * particular object, the "bpf_map" pointer is actually used
* as the "key" to search in the list of elem in
- * sk->sk_bpf_storage.
+ * the respective bpf_local_storage owned by the object.
*
- * Hence, consider sk->sk_bpf_storage is the mini-map
- * with the "bpf_map" pointer as the searching key.
+ * e.g. sk->sk_bpf_storage is the mini-map with the "bpf_map" pointer
+ * as the searching key.
*/
-struct bpf_sk_storage_map {
+struct bpf_local_storage_map {
struct bpf_map map;
/* Lookup elem does not require accessing the map.
*
@@ -46,55 +45,57 @@ struct bpf_sk_storage_map {
* link/unlink the elem from the map. Having
* multiple buckets to improve contention.
*/
- struct bucket *buckets;
+ struct bpf_local_storage_map_bucket *buckets;
u32 bucket_log;
u16 elem_size;
u16 cache_idx;
};

-struct bpf_sk_storage_data {
+struct bpf_local_storage_data {
/* smap is used as the searching key when looking up
- * from sk->sk_bpf_storage.
+ * from the object's bpf_local_storage.
*
* Put it in the same cacheline as the data to minimize
* the number of cachelines access during the cache hit case.
*/
- struct bpf_sk_storage_map __rcu *smap;
+ struct bpf_local_storage_map __rcu *smap;
u8 data[] __aligned(8);
};

-/* Linked to bpf_sk_storage and bpf_sk_storage_map */
-struct bpf_sk_storage_elem {
- struct hlist_node map_node; /* Linked to bpf_sk_storage_map */
- struct hlist_node snode; /* Linked to bpf_sk_storage */
- struct bpf_sk_storage __rcu *sk_storage;
+/* Linked to bpf_local_storage and bpf_local_storage_map */
+struct bpf_local_storage_elem {
+ struct hlist_node map_node; /* Linked to bpf_local_storage_map */
+ struct hlist_node snode; /* Linked to bpf_local_storage */
+ struct bpf_local_storage __rcu *local_storage;
struct rcu_head rcu;
/* 8 bytes hole */
/* The data is stored in aother cacheline to minimize
* the number of cachelines access during a cache hit.
*/
- struct bpf_sk_storage_data sdata ____cacheline_aligned;
+ struct bpf_local_storage_data sdata ____cacheline_aligned;
};

-#define SELEM(_SDATA) container_of((_SDATA), struct bpf_sk_storage_elem, sdata)
+#define SELEM(_SDATA) \
+ container_of((_SDATA), struct bpf_local_storage_elem, sdata)
#define SDATA(_SELEM) (&(_SELEM)->sdata)
-#define BPF_SK_STORAGE_CACHE_SIZE 16
+#define BPF_LOCAL_STORAGE_CACHE_SIZE 16

static DEFINE_SPINLOCK(cache_idx_lock);
-static u64 cache_idx_usage_counts[BPF_SK_STORAGE_CACHE_SIZE];
+static u64 cache_idx_usage_counts[BPF_LOCAL_STORAGE_CACHE_SIZE];

-struct bpf_sk_storage {
- struct bpf_sk_storage_data __rcu *cache[BPF_SK_STORAGE_CACHE_SIZE];
- struct hlist_head list; /* List of bpf_sk_storage_elem */
- struct sock *sk; /* The sk that owns the the above "list" of
- * bpf_sk_storage_elem.
+struct bpf_local_storage {
+ struct bpf_local_storage_data __rcu *cache[BPF_LOCAL_STORAGE_CACHE_SIZE];
+ struct hlist_head list; /* List of bpf_local_storage_elem */
+ struct sock *owner; /* The object that owns the above "list" of
+ * bpf_local_storage_elem.
*/
struct rcu_head rcu;
raw_spinlock_t lock; /* Protect adding/removing from the "list" */
};

-static struct bucket *select_bucket(struct bpf_sk_storage_map *smap,
- struct bpf_sk_storage_elem *selem)
+static struct bpf_local_storage_map_bucket *
+select_bucket(struct bpf_local_storage_map *smap,
+ struct bpf_local_storage_elem *selem)
{
return &smap->buckets[hash_ptr(selem, smap->bucket_log)];
}
@@ -111,21 +112,21 @@ static int omem_charge(struct sock *sk, unsigned int size)
return -ENOMEM;
}

-static bool selem_linked_to_sk(const struct bpf_sk_storage_elem *selem)
+static bool selem_linked_to_storage(const struct bpf_local_storage_elem *selem)
{
return !hlist_unhashed(&selem->snode);
}

-static bool selem_linked_to_map(const struct bpf_sk_storage_elem *selem)
+static bool selem_linked_to_map(const struct bpf_local_storage_elem *selem)
{
return !hlist_unhashed(&selem->map_node);
}

-static struct bpf_sk_storage_elem *selem_alloc(struct bpf_sk_storage_map *smap,
- struct sock *sk, void *value,
- bool charge_omem)
+static struct bpf_local_storage_elem *
+bpf_selem_alloc(struct bpf_local_storage_map *smap, struct sock *sk,
+ void *value, bool charge_omem)
{
- struct bpf_sk_storage_elem *selem;
+ struct bpf_local_storage_elem *selem;

if (charge_omem && omem_charge(sk, smap->elem_size))
return NULL;
@@ -143,89 +144,93 @@ static struct bpf_sk_storage_elem *selem_alloc(struct bpf_sk_storage_map *smap,
return NULL;
}

-/* sk_storage->lock must be held and selem->sk_storage == sk_storage.
+/* local_storage->lock must be held and selem->local_storage == local_storage.
* The caller must ensure selem->smap is still valid to be
* dereferenced for its smap->elem_size and smap->cache_idx.
*/
-static bool __selem_unlink_sk(struct bpf_sk_storage *sk_storage,
- struct bpf_sk_storage_elem *selem,
- bool uncharge_omem)
+static bool
+bpf_selem_unlink_storage_nolock(struct bpf_local_storage *local_storage,
+ struct bpf_local_storage_elem *selem,
+ bool uncharge_omem)
{
- struct bpf_sk_storage_map *smap;
- bool free_sk_storage;
+ struct bpf_local_storage_map *smap;
+ bool free_local_storage;
struct sock *sk;

smap = rcu_dereference(SDATA(selem)->smap);
- sk = sk_storage->sk;
+ sk = local_storage->owner;

- /* All uncharging on sk->sk_omem_alloc must be done first.
- * sk may be freed once the last selem is unlinked from sk_storage.
+ /* All uncharging on the owner must be done first.
+ * The owner may be freed once the last selem is unlinked
+ * from local_storage.
*/
if (uncharge_omem)
atomic_sub(smap->elem_size, &sk->sk_omem_alloc);

- free_sk_storage = hlist_is_singular_node(&selem->snode,
- &sk_storage->list);
- if (free_sk_storage) {
- atomic_sub(sizeof(struct bpf_sk_storage), &sk->sk_omem_alloc);
- sk_storage->sk = NULL;
+ free_local_storage = hlist_is_singular_node(&selem->snode,
+ &local_storage->list);
+ if (free_local_storage) {
+ atomic_sub(sizeof(struct bpf_local_storage), &sk->sk_omem_alloc);
+ local_storage->owner = NULL;
/* After this RCU_INIT, sk may be freed and cannot be used */
RCU_INIT_POINTER(sk->sk_bpf_storage, NULL);

- /* sk_storage is not freed now. sk_storage->lock is
- * still held and raw_spin_unlock_bh(&sk_storage->lock)
+ /* local_storage is not freed now. local_storage->lock is
+ * still held and raw_spin_unlock_bh(&local_storage->lock)
* will be done by the caller.
*
* Although the unlock will be done under
* rcu_read_lock(), it is more intutivie to
- * read if kfree_rcu(sk_storage, rcu) is done
- * after the raw_spin_unlock_bh(&sk_storage->lock).
+ * read if kfree_rcu(local_storage, rcu) is done
+ * after the raw_spin_unlock_bh(&local_storage->lock).
*
- * Hence, a "bool free_sk_storage" is returned
+ * Hence, a "bool free_local_storage" is returned
* to the caller which then calls the kfree_rcu()
* after unlock.
*/
}
hlist_del_init_rcu(&selem->snode);
- if (rcu_access_pointer(sk_storage->cache[smap->cache_idx]) ==
+ if (rcu_access_pointer(local_storage->cache[smap->cache_idx]) ==
SDATA(selem))
- RCU_INIT_POINTER(sk_storage->cache[smap->cache_idx], NULL);
+ RCU_INIT_POINTER(local_storage->cache[smap->cache_idx], NULL);

kfree_rcu(selem, rcu);

- return free_sk_storage;
+ return free_local_storage;
}

-static void selem_unlink_sk(struct bpf_sk_storage_elem *selem)
+static void __bpf_selem_unlink_storage(struct bpf_local_storage_elem *selem)
{
- struct bpf_sk_storage *sk_storage;
- bool free_sk_storage = false;
+ struct bpf_local_storage *local_storage;
+ bool free_local_storage = false;

- if (unlikely(!selem_linked_to_sk(selem)))
+ if (unlikely(!selem_linked_to_storage(selem)))
/* selem has already been unlinked from sk */
return;

- sk_storage = rcu_dereference(selem->sk_storage);
- raw_spin_lock_bh(&sk_storage->lock);
- if (likely(selem_linked_to_sk(selem)))
- free_sk_storage = __selem_unlink_sk(sk_storage, selem, true);
- raw_spin_unlock_bh(&sk_storage->lock);
+ local_storage = rcu_dereference(selem->local_storage);
+ raw_spin_lock_bh(&local_storage->lock);
+ if (likely(selem_linked_to_storage(selem)))
+ free_local_storage =
+ bpf_selem_unlink_storage_nolock(local_storage, selem, true);
+ raw_spin_unlock_bh(&local_storage->lock);

- if (free_sk_storage)
- kfree_rcu(sk_storage, rcu);
+ if (free_local_storage)
+ kfree_rcu(local_storage, rcu);
}

-static void __selem_link_sk(struct bpf_sk_storage *sk_storage,
- struct bpf_sk_storage_elem *selem)
+static void
+bpf_selem_link_storage_nolock(struct bpf_local_storage *local_storage,
+ struct bpf_local_storage_elem *selem)
{
- RCU_INIT_POINTER(selem->sk_storage, sk_storage);
- hlist_add_head(&selem->snode, &sk_storage->list);
+ RCU_INIT_POINTER(selem->local_storage, local_storage);
+ hlist_add_head(&selem->snode, &local_storage->list);
}

-static void selem_unlink_map(struct bpf_sk_storage_elem *selem)
+static void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem)
{
- struct bpf_sk_storage_map *smap;
- struct bucket *b;
+ struct bpf_local_storage_map *smap;
+ struct bpf_local_storage_map_bucket *b;

if (unlikely(!selem_linked_to_map(selem)))
/* selem has already be unlinked from smap */
@@ -239,10 +244,10 @@ static void selem_unlink_map(struct bpf_sk_storage_elem *selem)
raw_spin_unlock_bh(&b->lock);
}

-static void selem_link_map(struct bpf_sk_storage_map *smap,
- struct bpf_sk_storage_elem *selem)
+static void bpf_selem_link_map(struct bpf_local_storage_map *smap,
+ struct bpf_local_storage_elem *selem)
{
- struct bucket *b = select_bucket(smap, selem);
+ struct bpf_local_storage_map_bucket *b = select_bucket(smap, selem);

raw_spin_lock_bh(&b->lock);
RCU_INIT_POINTER(SDATA(selem)->smap, smap);
@@ -250,31 +255,31 @@ static void selem_link_map(struct bpf_sk_storage_map *smap,
raw_spin_unlock_bh(&b->lock);
}

-static void selem_unlink(struct bpf_sk_storage_elem *selem)
+static void bpf_selem_unlink(struct bpf_local_storage_elem *selem)
{
- /* Always unlink from map before unlinking from sk_storage
+ /* Always unlink from map before unlinking from local_storage
* because selem will be freed after successfully unlinked from
- * the sk_storage.
+ * the local_storage.
*/
- selem_unlink_map(selem);
- selem_unlink_sk(selem);
+ bpf_selem_unlink_map(selem);
+ __bpf_selem_unlink_storage(selem);
}

-static struct bpf_sk_storage_data *
-__sk_storage_lookup(struct bpf_sk_storage *sk_storage,
- struct bpf_sk_storage_map *smap,
- bool cacheit_lockit)
+static struct bpf_local_storage_data *
+bpf_local_storage_lookup(struct bpf_local_storage *local_storage,
+ struct bpf_local_storage_map *smap,
+ bool cacheit_lockit)
{
- struct bpf_sk_storage_data *sdata;
- struct bpf_sk_storage_elem *selem;
+ struct bpf_local_storage_data *sdata;
+ struct bpf_local_storage_elem *selem;

/* Fast path (cache hit) */
- sdata = rcu_dereference(sk_storage->cache[smap->cache_idx]);
+ sdata = rcu_dereference(local_storage->cache[smap->cache_idx]);
if (sdata && rcu_access_pointer(sdata->smap) == smap)
return sdata;

/* Slow path (cache miss) */
- hlist_for_each_entry_rcu(selem, &sk_storage->list, snode)
+ hlist_for_each_entry_rcu(selem, &local_storage->list, snode)
if (rcu_access_pointer(SDATA(selem)->smap) == smap)
break;

@@ -286,33 +291,33 @@ __sk_storage_lookup(struct bpf_sk_storage *sk_storage,
/* spinlock is needed to avoid racing with the
* parallel delete. Otherwise, publishing an already
* deleted sdata to the cache will become a use-after-free
- * problem in the next __sk_storage_lookup().
+ * problem in the next bpf_local_storage_lookup().
*/
- raw_spin_lock_bh(&sk_storage->lock);
- if (selem_linked_to_sk(selem))
- rcu_assign_pointer(sk_storage->cache[smap->cache_idx],
+ raw_spin_lock_bh(&local_storage->lock);
+ if (selem_linked_to_storage(selem))
+ rcu_assign_pointer(local_storage->cache[smap->cache_idx],
sdata);
- raw_spin_unlock_bh(&sk_storage->lock);
+ raw_spin_unlock_bh(&local_storage->lock);
}

return sdata;
}

-static struct bpf_sk_storage_data *
+static struct bpf_local_storage_data *
sk_storage_lookup(struct sock *sk, struct bpf_map *map, bool cacheit_lockit)
{
- struct bpf_sk_storage *sk_storage;
- struct bpf_sk_storage_map *smap;
+ struct bpf_local_storage *sk_storage;
+ struct bpf_local_storage_map *smap;

sk_storage = rcu_dereference(sk->sk_bpf_storage);
if (!sk_storage)
return NULL;

- smap = (struct bpf_sk_storage_map *)map;
- return __sk_storage_lookup(sk_storage, smap, cacheit_lockit);
+ smap = (struct bpf_local_storage_map *)map;
+ return bpf_local_storage_lookup(sk_storage, smap, cacheit_lockit);
}

-static int check_flags(const struct bpf_sk_storage_data *old_sdata,
+static int check_flags(const struct bpf_local_storage_data *old_sdata,
u64 map_flags)
{
if (old_sdata && (map_flags & ~BPF_F_LOCK) == BPF_NOEXIST)
@@ -327,10 +332,10 @@ static int check_flags(const struct bpf_sk_storage_data *old_sdata,
}

static int sk_storage_alloc(struct sock *sk,
- struct bpf_sk_storage_map *smap,
- struct bpf_sk_storage_elem *first_selem)
+ struct bpf_local_storage_map *smap,
+ struct bpf_local_storage_elem *first_selem)
{
- struct bpf_sk_storage *prev_sk_storage, *sk_storage;
+ struct bpf_local_storage *prev_sk_storage, *sk_storage;
int err;

err = omem_charge(sk, sizeof(*sk_storage));
@@ -344,10 +349,10 @@ static int sk_storage_alloc(struct sock *sk,
}
INIT_HLIST_HEAD(&sk_storage->list);
raw_spin_lock_init(&sk_storage->lock);
- sk_storage->sk = sk;
+ sk_storage->owner = sk;

- __selem_link_sk(sk_storage, first_selem);
- selem_link_map(smap, first_selem);
+ bpf_selem_link_storage_nolock(sk_storage, first_selem);
+ bpf_selem_link_map(smap, first_selem);
/* Publish sk_storage to sk. sk->sk_lock cannot be acquired.
* Hence, atomic ops is used to set sk->sk_bpf_storage
* from NULL to the newly allocated sk_storage ptr.
@@ -357,17 +362,17 @@ static int sk_storage_alloc(struct sock *sk,
* the sk->sk_bpf_storage, the sk_storage->lock must
* be held before setting sk->sk_bpf_storage to NULL.
*/
- prev_sk_storage = cmpxchg((struct bpf_sk_storage **)&sk->sk_bpf_storage,
+ prev_sk_storage = cmpxchg((struct bpf_local_storage **)&sk->sk_bpf_storage,
NULL, sk_storage);
if (unlikely(prev_sk_storage)) {
- selem_unlink_map(first_selem);
+ bpf_selem_unlink_map(first_selem);
err = -EAGAIN;
goto uncharge;

/* Note that even first_selem was linked to smap's
* bucket->list, first_selem can be freed immediately
* (instead of kfree_rcu) because
- * bpf_sk_storage_map_free() does a
+ * bpf_local_storage_map_free() does a
* synchronize_rcu() before walking the bucket->list.
* Hence, no one is accessing selem from the
* bucket->list under rcu_read_lock().
@@ -387,15 +392,14 @@ static int sk_storage_alloc(struct sock *sk,
* Otherwise, it will become a leak (and other memory issues
* during map destruction).
*/
-static struct bpf_sk_storage_data *sk_storage_update(struct sock *sk,
- struct bpf_map *map,
- void *value,
- u64 map_flags)
+static struct bpf_local_storage_data *
+bpf_local_storage_update(struct sock *sk, struct bpf_map *map, void *value,
+ u64 map_flags)
{
- struct bpf_sk_storage_data *old_sdata = NULL;
- struct bpf_sk_storage_elem *selem;
- struct bpf_sk_storage *sk_storage;
- struct bpf_sk_storage_map *smap;
+ struct bpf_local_storage_data *old_sdata = NULL;
+ struct bpf_local_storage_elem *selem;
+ struct bpf_local_storage *local_storage;
+ struct bpf_local_storage_map *smap;
int err;

/* BPF_EXIST and BPF_NOEXIST cannot be both set */
@@ -404,15 +408,15 @@ static struct bpf_sk_storage_data *sk_storage_update(struct sock *sk,
unlikely((map_flags & BPF_F_LOCK) && !map_value_has_spin_lock(map)))
return ERR_PTR(-EINVAL);

- smap = (struct bpf_sk_storage_map *)map;
- sk_storage = rcu_dereference(sk->sk_bpf_storage);
- if (!sk_storage || hlist_empty(&sk_storage->list)) {
- /* Very first elem for this sk */
+ smap = (struct bpf_local_storage_map *)map;
+ local_storage = rcu_dereference(sk->sk_bpf_storage);
+ if (!local_storage || hlist_empty(&local_storage->list)) {
+ /* Very first elem for the owner */
err = check_flags(NULL, map_flags);
if (err)
return ERR_PTR(err);

- selem = selem_alloc(smap, sk, value, true);
+ selem = bpf_selem_alloc(smap, sk, value, true);
if (!selem)
return ERR_PTR(-ENOMEM);

@@ -428,25 +432,26 @@ static struct bpf_sk_storage_data *sk_storage_update(struct sock *sk,

if ((map_flags & BPF_F_LOCK) && !(map_flags & BPF_NOEXIST)) {
/* Hoping to find an old_sdata to do inline update
- * such that it can avoid taking the sk_storage->lock
+ * such that it can avoid taking the local_storage->lock
* and changing the lists.
*/
- old_sdata = __sk_storage_lookup(sk_storage, smap, false);
+ old_sdata =
+ bpf_local_storage_lookup(local_storage, smap, false);
err = check_flags(old_sdata, map_flags);
if (err)
return ERR_PTR(err);
- if (old_sdata && selem_linked_to_sk(SELEM(old_sdata))) {
+ if (old_sdata && selem_linked_to_storage(SELEM(old_sdata))) {
copy_map_value_locked(map, old_sdata->data,
value, false);
return old_sdata;
}
}

- raw_spin_lock_bh(&sk_storage->lock);
+ raw_spin_lock_bh(&local_storage->lock);

- /* Recheck sk_storage->list under sk_storage->lock */
- if (unlikely(hlist_empty(&sk_storage->list))) {
- /* A parallel del is happening and sk_storage is going
+ /* Recheck local_storage->list under local_storage->lock */
+ if (unlikely(hlist_empty(&local_storage->list))) {
+ /* A parallel del is happening and local_storage is going
* away. It has just been checked before, so very
* unlikely. Return instead of retry to keep things
* simple.
@@ -455,7 +460,7 @@ static struct bpf_sk_storage_data *sk_storage_update(struct sock *sk,
goto unlock_err;
}

- old_sdata = __sk_storage_lookup(sk_storage, smap, false);
+ old_sdata = bpf_local_storage_lookup(local_storage, smap, false);
err = check_flags(old_sdata, map_flags);
if (err)
goto unlock_err;
@@ -466,50 +471,52 @@ static struct bpf_sk_storage_data *sk_storage_update(struct sock *sk,
goto unlock;
}

- /* sk_storage->lock is held. Hence, we are sure
+ /* local_storage->lock is held. Hence, we are sure
* we can unlink and uncharge the old_sdata successfully
* later. Hence, instead of charging the new selem now
* and then uncharge the old selem later (which may cause
* a potential but unnecessary charge failure), avoid taking
* a charge at all here (the "!old_sdata" check) and the
- * old_sdata will not be uncharged later during __selem_unlink_sk().
+ * old_sdata will not be uncharged later during
+ * bpf_selem_unlink_storage_nolock().
*/
- selem = selem_alloc(smap, sk, value, !old_sdata);
+ selem = bpf_selem_alloc(smap, sk, value, !old_sdata);
if (!selem) {
err = -ENOMEM;
goto unlock_err;
}

/* First, link the new selem to the map */
- selem_link_map(smap, selem);
+ bpf_selem_link_map(smap, selem);

- /* Second, link (and publish) the new selem to sk_storage */
- __selem_link_sk(sk_storage, selem);
+ /* Second, link (and publish) the new selem to local_storage */
+ bpf_selem_link_storage_nolock(local_storage, selem);

/* Third, remove old selem, SELEM(old_sdata) */
if (old_sdata) {
- selem_unlink_map(SELEM(old_sdata));
- __selem_unlink_sk(sk_storage, SELEM(old_sdata), false);
+ bpf_selem_unlink_map(SELEM(old_sdata));
+ bpf_selem_unlink_storage_nolock(local_storage, SELEM(old_sdata),
+ false);
}

unlock:
- raw_spin_unlock_bh(&sk_storage->lock);
+ raw_spin_unlock_bh(&local_storage->lock);
return SDATA(selem);

unlock_err:
- raw_spin_unlock_bh(&sk_storage->lock);
+ raw_spin_unlock_bh(&local_storage->lock);
return ERR_PTR(err);
}

static int sk_storage_delete(struct sock *sk, struct bpf_map *map)
{
- struct bpf_sk_storage_data *sdata;
+ struct bpf_local_storage_data *sdata;

sdata = sk_storage_lookup(sk, map, false);
if (!sdata)
return -ENOENT;

- selem_unlink(SELEM(sdata));
+ bpf_selem_unlink(SELEM(sdata));

return 0;
}
@@ -521,7 +528,7 @@ static u16 cache_idx_get(void)

spin_lock(&cache_idx_lock);

- for (i = 0; i < BPF_SK_STORAGE_CACHE_SIZE; i++) {
+ 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];
res = i;
@@ -548,8 +555,8 @@ static void cache_idx_free(u16 idx)
/* Called by __sk_destruct() & bpf_sk_storage_clone() */
void bpf_sk_storage_free(struct sock *sk)
{
- struct bpf_sk_storage_elem *selem;
- struct bpf_sk_storage *sk_storage;
+ struct bpf_local_storage_elem *selem;
+ struct bpf_local_storage *sk_storage;
bool free_sk_storage = false;
struct hlist_node *n;

@@ -565,7 +572,7 @@ void bpf_sk_storage_free(struct sock *sk)
* Thus, no elem can be added-to or deleted-from the
* sk_storage->list by the bpf_prog or by the bpf-map's syscall.
*
- * It is racing with bpf_sk_storage_map_free() alone
+ * It is racing with bpf_local_storage_map_free() alone
* when unlinking elem from the sk_storage->list and
* the map's bucket->list.
*/
@@ -574,8 +581,9 @@ void bpf_sk_storage_free(struct sock *sk)
/* Always unlink from map before unlinking from
* sk_storage.
*/
- selem_unlink_map(selem);
- free_sk_storage = __selem_unlink_sk(sk_storage, selem, true);
+ bpf_selem_unlink_map(selem);
+ free_sk_storage = bpf_selem_unlink_storage_nolock(sk_storage,
+ selem, true);
}
raw_spin_unlock_bh(&sk_storage->lock);
rcu_read_unlock();
@@ -584,14 +592,14 @@ void bpf_sk_storage_free(struct sock *sk)
kfree_rcu(sk_storage, rcu);
}

-static void bpf_sk_storage_map_free(struct bpf_map *map)
+static void bpf_local_storage_map_free(struct bpf_map *map)
{
- struct bpf_sk_storage_elem *selem;
- struct bpf_sk_storage_map *smap;
- struct bucket *b;
+ struct bpf_local_storage_elem *selem;
+ struct bpf_local_storage_map *smap;
+ struct bpf_local_storage_map_bucket *b;
unsigned int i;

- smap = (struct bpf_sk_storage_map *)map;
+ smap = (struct bpf_local_storage_map *)map;

cache_idx_free(smap->cache_idx);

@@ -604,10 +612,10 @@ static void bpf_sk_storage_map_free(struct bpf_map *map)

/* bpf prog and the userspace can no longer access this map
* now. No new selem (of this map) can be added
- * to the sk->sk_bpf_storage or to the map bucket's list.
+ * to the owner->storage or to the map bucket's list.
*
* The elem of this map can be cleaned up here
- * or
+ * or when the storage is freed e.g.
* by bpf_sk_storage_free() during __sk_destruct().
*/
for (i = 0; i < (1U << smap->bucket_log); i++) {
@@ -615,26 +623,26 @@ static void bpf_sk_storage_map_free(struct bpf_map *map)

rcu_read_lock();
/* No one is adding to b->list now */
- while ((selem = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(&b->list)),
- struct bpf_sk_storage_elem,
- map_node))) {
- selem_unlink(selem);
+ while ((selem = hlist_entry_safe(
+ rcu_dereference_raw(hlist_first_rcu(&b->list)),
+ struct bpf_local_storage_elem, map_node))) {
+ bpf_selem_unlink(selem);
cond_resched_rcu();
}
rcu_read_unlock();
}

- /* bpf_sk_storage_free() may still need to access the map.
- * e.g. bpf_sk_storage_free() has unlinked selem from the map
+ /* While freeing the storage we may still need to access the map.
+ *
+ * e.g. when bpf_sk_storage_free() has unlinked selem from the map
* which then made the above while((selem = ...)) loop
- * exited immediately.
+ * exit immediately.
*
- * However, the bpf_sk_storage_free() still needs to access
- * the smap->elem_size to do the uncharging in
- * __selem_unlink_sk().
+ * However, while freeing the storage one still needs to access the
+ * smap->elem_size to do the uncharging in
+ * bpf_selem_unlink_storage_nolock().
*
- * Hence, wait another rcu grace period for the
- * bpf_sk_storage_free() to finish.
+ * Hence, wait another rcu grace period for the storage to be freed.
*/
synchronize_rcu();

@@ -645,14 +653,15 @@ static void bpf_sk_storage_map_free(struct bpf_map *map)
/* U16_MAX is much more than enough for sk local storage
* considering a tcp_sock is ~2k.
*/
-#define MAX_VALUE_SIZE \
+#define BPF_LOCAL_STORAGE_MAX_VALUE_SIZE \
min_t(u32, \
- (KMALLOC_MAX_SIZE - MAX_BPF_STACK - sizeof(struct bpf_sk_storage_elem)), \
- (U16_MAX - sizeof(struct bpf_sk_storage_elem)))
+ (KMALLOC_MAX_SIZE - MAX_BPF_STACK - \
+ sizeof(struct bpf_local_storage_elem)), \
+ (U16_MAX - sizeof(struct bpf_local_storage_elem)))

-static int bpf_sk_storage_map_alloc_check(union bpf_attr *attr)
+static int bpf_local_storage_map_alloc_check(union bpf_attr *attr)
{
- if (attr->map_flags & ~SK_STORAGE_CREATE_FLAG_MASK ||
+ if (attr->map_flags & ~BPF_LOCAL_STORAGE_CREATE_FLAG_MASK ||
!(attr->map_flags & BPF_F_NO_PREALLOC) ||
attr->max_entries ||
attr->key_size != sizeof(int) || !attr->value_size ||
@@ -663,15 +672,15 @@ static int bpf_sk_storage_map_alloc_check(union bpf_attr *attr)
if (!bpf_capable())
return -EPERM;

- if (attr->value_size > MAX_VALUE_SIZE)
+ if (attr->value_size > BPF_LOCAL_STORAGE_MAX_VALUE_SIZE)
return -E2BIG;

return 0;
}

-static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr)
+static struct bpf_map *bpf_local_storage_map_alloc(union bpf_attr *attr)
{
- struct bpf_sk_storage_map *smap;
+ struct bpf_local_storage_map *smap;
unsigned int i;
u32 nbuckets;
u64 cost;
@@ -707,7 +716,8 @@ static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr)
raw_spin_lock_init(&smap->buckets[i].lock);
}

- smap->elem_size = sizeof(struct bpf_sk_storage_elem) + attr->value_size;
+ smap->elem_size =
+ sizeof(struct bpf_local_storage_elem) + attr->value_size;
smap->cache_idx = cache_idx_get();

return &smap->map;
@@ -719,10 +729,10 @@ static int notsupp_get_next_key(struct bpf_map *map, void *key,
return -ENOTSUPP;
}

-static int bpf_sk_storage_map_check_btf(const struct bpf_map *map,
- const struct btf *btf,
- const struct btf_type *key_type,
- const struct btf_type *value_type)
+static int bpf_local_storage_map_check_btf(const struct bpf_map *map,
+ const struct btf *btf,
+ const struct btf_type *key_type,
+ const struct btf_type *value_type)
{
u32 int_data;

@@ -738,7 +748,7 @@ static int bpf_sk_storage_map_check_btf(const struct bpf_map *map,

static void *bpf_fd_sk_storage_lookup_elem(struct bpf_map *map, void *key)
{
- struct bpf_sk_storage_data *sdata;
+ struct bpf_local_storage_data *sdata;
struct socket *sock;
int fd, err;

@@ -756,14 +766,15 @@ static void *bpf_fd_sk_storage_lookup_elem(struct bpf_map *map, void *key)
static int bpf_fd_sk_storage_update_elem(struct bpf_map *map, void *key,
void *value, u64 map_flags)
{
- struct bpf_sk_storage_data *sdata;
+ struct bpf_local_storage_data *sdata;
struct socket *sock;
int fd, err;

fd = *(int *)key;
sock = sockfd_lookup(fd, &err);
if (sock) {
- sdata = sk_storage_update(sock->sk, map, value, map_flags);
+ sdata = bpf_local_storage_update(sock->sk, map, value,
+ map_flags);
sockfd_put(sock);
return PTR_ERR_OR_ZERO(sdata);
}
@@ -787,14 +798,14 @@ static int bpf_fd_sk_storage_delete_elem(struct bpf_map *map, void *key)
return err;
}

-static struct bpf_sk_storage_elem *
+static struct bpf_local_storage_elem *
bpf_sk_storage_clone_elem(struct sock *newsk,
- struct bpf_sk_storage_map *smap,
- struct bpf_sk_storage_elem *selem)
+ struct bpf_local_storage_map *smap,
+ struct bpf_local_storage_elem *selem)
{
- struct bpf_sk_storage_elem *copy_selem;
+ struct bpf_local_storage_elem *copy_selem;

- copy_selem = selem_alloc(smap, newsk, NULL, true);
+ copy_selem = bpf_selem_alloc(smap, newsk, NULL, true);
if (!copy_selem)
return NULL;

@@ -810,9 +821,9 @@ bpf_sk_storage_clone_elem(struct sock *newsk,

int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
{
- struct bpf_sk_storage *new_sk_storage = NULL;
- struct bpf_sk_storage *sk_storage;
- struct bpf_sk_storage_elem *selem;
+ struct bpf_local_storage *new_sk_storage = NULL;
+ struct bpf_local_storage *sk_storage;
+ struct bpf_local_storage_elem *selem;
int ret = 0;

RCU_INIT_POINTER(newsk->sk_bpf_storage, NULL);
@@ -824,8 +835,8 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
goto out;

hlist_for_each_entry_rcu(selem, &sk_storage->list, snode) {
- struct bpf_sk_storage_elem *copy_selem;
- struct bpf_sk_storage_map *smap;
+ struct bpf_local_storage_elem *copy_selem;
+ struct bpf_local_storage_map *smap;
struct bpf_map *map;

smap = rcu_dereference(SDATA(selem)->smap);
@@ -833,7 +844,7 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
continue;

/* Note that for lockless listeners adding new element
- * here can race with cleanup in bpf_sk_storage_map_free.
+ * here can race with cleanup in bpf_local_storage_map_free.
* Try to grab map refcnt to make sure that it's still
* alive and prevent concurrent removal.
*/
@@ -849,8 +860,8 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
}

if (new_sk_storage) {
- selem_link_map(smap, copy_selem);
- __selem_link_sk(new_sk_storage, copy_selem);
+ bpf_selem_link_map(smap, copy_selem);
+ bpf_selem_link_storage_nolock(new_sk_storage, copy_selem);
} else {
ret = sk_storage_alloc(newsk, smap, copy_selem);
if (ret) {
@@ -861,7 +872,8 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
goto out;
}

- new_sk_storage = rcu_dereference(copy_selem->sk_storage);
+ new_sk_storage =
+ rcu_dereference(copy_selem->local_storage);
}
bpf_map_put(map);
}
@@ -879,7 +891,7 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk,
void *, value, u64, flags)
{
- struct bpf_sk_storage_data *sdata;
+ struct bpf_local_storage_data *sdata;

if (flags > BPF_SK_STORAGE_GET_F_CREATE)
return (unsigned long)NULL;
@@ -895,7 +907,7 @@ BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk,
* destruction).
*/
refcount_inc_not_zero(&sk->sk_refcnt)) {
- sdata = sk_storage_update(sk, map, value, BPF_NOEXIST);
+ sdata = bpf_local_storage_update(sk, map, value, BPF_NOEXIST);
/* sk must be a fullsock (guaranteed by verifier),
* so sock_gen_put() is unnecessary.
*/
@@ -922,15 +934,15 @@ BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk)

static int sk_storage_map_btf_id;
const struct bpf_map_ops sk_storage_map_ops = {
- .map_alloc_check = bpf_sk_storage_map_alloc_check,
- .map_alloc = bpf_sk_storage_map_alloc,
- .map_free = bpf_sk_storage_map_free,
+ .map_alloc_check = bpf_local_storage_map_alloc_check,
+ .map_alloc = bpf_local_storage_map_alloc,
+ .map_free = bpf_local_storage_map_free,
.map_get_next_key = notsupp_get_next_key,
.map_lookup_elem = bpf_fd_sk_storage_lookup_elem,
.map_update_elem = bpf_fd_sk_storage_update_elem,
.map_delete_elem = bpf_fd_sk_storage_delete_elem,
- .map_check_btf = bpf_sk_storage_map_check_btf,
- .map_btf_name = "bpf_sk_storage_map",
+ .map_check_btf = bpf_local_storage_map_check_btf,
+ .map_btf_name = "bpf_local_storage_map",
.map_btf_id = &sk_storage_map_btf_id,
};

@@ -1022,7 +1034,7 @@ bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs)
u32 nr_maps = 0;
int rem, err;

- /* bpf_sk_storage_map is currently limited to CAP_SYS_ADMIN as
+ /* bpf_local_storage_map is currently limited to CAP_SYS_ADMIN as
* the map_alloc_check() side also does.
*/
if (!bpf_capable())
@@ -1072,13 +1084,13 @@ bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs)
}
EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_alloc);

-static int diag_get(struct bpf_sk_storage_data *sdata, struct sk_buff *skb)
+static int diag_get(struct bpf_local_storage_data *sdata, struct sk_buff *skb)
{
struct nlattr *nla_stg, *nla_value;
- struct bpf_sk_storage_map *smap;
+ struct bpf_local_storage_map *smap;

/* It cannot exceed max nlattr's payload */
- BUILD_BUG_ON(U16_MAX - NLA_HDRLEN < MAX_VALUE_SIZE);
+ BUILD_BUG_ON(U16_MAX - NLA_HDRLEN < BPF_LOCAL_STORAGE_MAX_VALUE_SIZE);

nla_stg = nla_nest_start(skb, SK_DIAG_BPF_STORAGE);
if (!nla_stg)
@@ -1114,9 +1126,9 @@ static int bpf_sk_storage_diag_put_all(struct sock *sk, struct sk_buff *skb,
{
/* stg_array_type (e.g. INET_DIAG_BPF_SK_STORAGES) */
unsigned int diag_size = nla_total_size(0);
- struct bpf_sk_storage *sk_storage;
- struct bpf_sk_storage_elem *selem;
- struct bpf_sk_storage_map *smap;
+ struct bpf_local_storage *sk_storage;
+ struct bpf_local_storage_elem *selem;
+ struct bpf_local_storage_map *smap;
struct nlattr *nla_stgs;
unsigned int saved_len;
int err = 0;
@@ -1169,8 +1181,8 @@ int bpf_sk_storage_diag_put(struct bpf_sk_storage_diag *diag,
{
/* stg_array_type (e.g. INET_DIAG_BPF_SK_STORAGES) */
unsigned int diag_size = nla_total_size(0);
- struct bpf_sk_storage *sk_storage;
- struct bpf_sk_storage_data *sdata;
+ struct bpf_local_storage *sk_storage;
+ struct bpf_local_storage_data *sdata;
struct nlattr *nla_stgs;
unsigned int saved_len;
int err = 0;
@@ -1197,8 +1209,8 @@ int bpf_sk_storage_diag_put(struct bpf_sk_storage_diag *diag,

saved_len = skb->len;
for (i = 0; i < diag->nr_maps; i++) {
- sdata = __sk_storage_lookup(sk_storage,
- (struct bpf_sk_storage_map *)diag->maps[i],
+ sdata = bpf_local_storage_lookup(sk_storage,
+ (struct bpf_local_storage_map *)diag->maps[i],
false);

if (!sdata)
@@ -1235,19 +1247,19 @@ struct bpf_iter_seq_sk_storage_map_info {
unsigned skip_elems;
};

-static struct bpf_sk_storage_elem *
+static struct bpf_local_storage_elem *
bpf_sk_storage_map_seq_find_next(struct bpf_iter_seq_sk_storage_map_info *info,
- struct bpf_sk_storage_elem *prev_selem)
+ struct bpf_local_storage_elem *prev_selem)
{
- struct bpf_sk_storage *sk_storage;
- struct bpf_sk_storage_elem *selem;
+ struct bpf_local_storage *sk_storage;
+ struct bpf_local_storage_elem *selem;
u32 skip_elems = info->skip_elems;
- struct bpf_sk_storage_map *smap;
+ struct bpf_local_storage_map *smap;
u32 bucket_id = info->bucket_id;
u32 i, count, n_buckets;
- struct bucket *b;
+ struct bpf_local_storage_map_bucket *b;

- smap = (struct bpf_sk_storage_map *)info->map;
+ smap = (struct bpf_local_storage_map *)info->map;
n_buckets = 1U << smap->bucket_log;
if (bucket_id >= n_buckets)
return NULL;
@@ -1257,7 +1269,7 @@ bpf_sk_storage_map_seq_find_next(struct bpf_iter_seq_sk_storage_map_info *info,
count = 0;
while (selem) {
selem = hlist_entry_safe(selem->map_node.next,
- struct bpf_sk_storage_elem, map_node);
+ struct bpf_local_storage_elem, map_node);
if (!selem) {
/* not found, unlock and go to the next bucket */
b = &smap->buckets[bucket_id++];
@@ -1265,7 +1277,7 @@ bpf_sk_storage_map_seq_find_next(struct bpf_iter_seq_sk_storage_map_info *info,
skip_elems = 0;
break;
}
- sk_storage = rcu_dereference_raw(selem->sk_storage);
+ sk_storage = rcu_dereference_raw(selem->local_storage);
if (sk_storage) {
info->skip_elems = skip_elems + count;
return selem;
@@ -1278,7 +1290,7 @@ bpf_sk_storage_map_seq_find_next(struct bpf_iter_seq_sk_storage_map_info *info,
raw_spin_lock_bh(&b->lock);
count = 0;
hlist_for_each_entry(selem, &b->list, map_node) {
- sk_storage = rcu_dereference_raw(selem->sk_storage);
+ sk_storage = rcu_dereference_raw(selem->local_storage);
if (sk_storage && count >= skip_elems) {
info->bucket_id = i;
info->skip_elems = count;
@@ -1297,7 +1309,7 @@ bpf_sk_storage_map_seq_find_next(struct bpf_iter_seq_sk_storage_map_info *info,

static void *bpf_sk_storage_map_seq_start(struct seq_file *seq, loff_t *pos)
{
- struct bpf_sk_storage_elem *selem;
+ struct bpf_local_storage_elem *selem;

selem = bpf_sk_storage_map_seq_find_next(seq->private, NULL);
if (!selem)
@@ -1330,11 +1342,11 @@ DEFINE_BPF_ITER_FUNC(bpf_sk_storage_map, struct bpf_iter_meta *meta,
void *value)

static int __bpf_sk_storage_map_seq_show(struct seq_file *seq,
- struct bpf_sk_storage_elem *selem)
+ struct bpf_local_storage_elem *selem)
{
struct bpf_iter_seq_sk_storage_map_info *info = seq->private;
struct bpf_iter__bpf_sk_storage_map ctx = {};
- struct bpf_sk_storage *sk_storage;
+ struct bpf_local_storage *sk_storage;
struct bpf_iter_meta meta;
struct bpf_prog *prog;
int ret = 0;
@@ -1345,8 +1357,8 @@ static int __bpf_sk_storage_map_seq_show(struct seq_file *seq,
ctx.meta = &meta;
ctx.map = info->map;
if (selem) {
- sk_storage = rcu_dereference_raw(selem->sk_storage);
- ctx.sk = sk_storage->sk;
+ sk_storage = rcu_dereference_raw(selem->local_storage);
+ ctx.sk = sk_storage->owner;
ctx.value = SDATA(selem)->data;
}
ret = bpf_iter_run_prog(prog, &ctx);
@@ -1363,13 +1375,13 @@ static int bpf_sk_storage_map_seq_show(struct seq_file *seq, void *v)
static void bpf_sk_storage_map_seq_stop(struct seq_file *seq, void *v)
{
struct bpf_iter_seq_sk_storage_map_info *info = seq->private;
- struct bpf_sk_storage_map *smap;
- struct bucket *b;
+ struct bpf_local_storage_map *smap;
+ struct bpf_local_storage_map_bucket *b;

if (!v) {
(void)__bpf_sk_storage_map_seq_show(seq, v);
} else {
- smap = (struct bpf_sk_storage_map *)info->map;
+ smap = (struct bpf_local_storage_map *)info->map;
b = &smap->buckets[info->bucket_id];
raw_spin_unlock_bh(&b->lock);
}
--
2.28.0.297.g1956fa8f8d-goog