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Subject[PATCH bpf-next 2/4] bpf: Implement bpf_local_storage for inodes
Date
From: KP Singh <kpsingh@google.com>

Similar to bpf_local_storage for sockets, add local storage for inodes.
The life-cycle of storage is managed with the life-cycle of the inode.
i.e. the storage is destroyed along with the owning inode.

Since, the intention is to use this in LSM programs, the destruction is
done after security_inode_free in __destroy_inode.

Signed-off-by: KP Singh <kpsingh@google.com>
---
fs/inode.c | 3 +
include/linux/bpf_local_storage.h | 6 +
include/linux/bpf_types.h | 1 +
include/linux/fs.h | 5 +
include/uapi/linux/bpf.h | 41 +++-
kernel/bpf/bpf_local_storage.c | 321 +++++++++++++++++++++++++++++-
kernel/bpf/syscall.c | 3 +-
kernel/bpf/verifier.c | 10 +
tools/bpf/bpftool/map.c | 1 +
tools/include/uapi/linux/bpf.h | 41 +++-
tools/lib/bpf/libbpf_probes.c | 5 +-
11 files changed, 431 insertions(+), 6 deletions(-)

diff --git a/fs/inode.c b/fs/inode.c
index cc6e701b7e5d..91c81644f33d 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -22,6 +22,7 @@
#include <linux/list_lru.h>
#include <linux/iversion.h>
#include <trace/events/writeback.h>
+#include <linux/bpf_local_storage.h>
#include "internal.h"

/*
@@ -257,6 +258,8 @@ void __destroy_inode(struct inode *inode)
security_inode_free(inode);
fsnotify_inode_delete(inode);
locks_free_lock_context(inode);
+ bpf_inode_storage_free(inode);
+
if (!inode->i_nlink) {
WARN_ON(atomic_long_read(&inode->i_sb->s_remove_count) == 0);
atomic_long_dec(&inode->i_sb->s_remove_count);
diff --git a/include/linux/bpf_local_storage.h b/include/linux/bpf_local_storage.h
index 85524f18cd91..c6837e7838fc 100644
--- a/include/linux/bpf_local_storage.h
+++ b/include/linux/bpf_local_storage.h
@@ -9,6 +9,8 @@ void bpf_sk_storage_free(struct sock *sk);

extern const struct bpf_func_proto bpf_sk_storage_get_proto;
extern const struct bpf_func_proto bpf_sk_storage_delete_proto;
+extern const struct bpf_func_proto bpf_inode_storage_get_proto;
+extern const struct bpf_func_proto bpf_inode_storage_delete_proto;

struct bpf_sk_storage_diag;
struct sk_buff;
@@ -16,6 +18,7 @@ struct nlattr;
struct sock;

#ifdef CONFIG_BPF_SYSCALL
+void bpf_inode_storage_free(struct inode *inode);
int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk);
struct bpf_sk_storage_diag *
bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs);
@@ -35,6 +38,9 @@ bpf_sk_storage_diag_alloc(const struct nlattr *nla)
{
return NULL;
}
+static inline void void bpf_inode_storage_free(struct inode *inode)
+{
+}
static inline void bpf_sk_storage_diag_free(struct bpf_sk_storage_diag *diag)
{
}
diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
index 29d22752fc87..07181fb89bdd 100644
--- a/include/linux/bpf_types.h
+++ b/include/linux/bpf_types.h
@@ -101,6 +101,7 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_HASH_OF_MAPS, htab_of_maps_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP, dev_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP_HASH, dev_map_hash_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_SK_STORAGE, sk_storage_map_ops)
+BPF_MAP_TYPE(BPF_MAP_TYPE_INODE_STORAGE, inode_storage_map_ops)
#if defined(CONFIG_BPF_STREAM_PARSER)
BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKMAP, sock_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKHASH, sock_hash_ops)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 5ee9e583bde2..23a6b8fbd381 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -624,6 +624,7 @@ is_uncached_acl(struct posix_acl *acl)
#define IOP_DEFAULT_READLINK 0x0010

struct fsnotify_mark_connector;
+struct bpf_local_storage;

/*
* Keep mostly read-only and often accessed (especially for
@@ -740,6 +741,10 @@ struct inode {
struct fsverity_info *i_verity_info;
#endif

+#ifdef CONFIG_BPF_SYSCALL
+ struct bpf_local_storage __rcu *inode_bpf_storage;
+#endif
+
void *i_private; /* fs or device private pointer */
} __randomize_layout;

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 4a202eea15c0..410fb2e5fdd4 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -147,6 +147,7 @@ enum bpf_map_type {
BPF_MAP_TYPE_SK_STORAGE,
BPF_MAP_TYPE_DEVMAP_HASH,
BPF_MAP_TYPE_STRUCT_OPS,
+ BPF_MAP_TYPE_INODE_STORAGE,
};

/* Note that tracing related programs such as
@@ -3157,6 +3158,42 @@ union bpf_attr {
* **bpf_sk_cgroup_id**\ ().
* Return
* The id is returned or 0 in case the id could not be retrieved.
+ *
+ * void *bpf_inode_storage_get(struct bpf_map *map, void *inode, void *value, u64 flags)
+ * Description
+ * Get a bpf_local_storage from an *inode*.
+ *
+ * Logically, it could be thought of as getting the value from
+ * a *map* with *inode* as the **key**. From this
+ * perspective, the usage is not much different from
+ * **bpf_map_lookup_elem**\ (*map*, **&**\ *inode*) except this
+ * helper enforces the key must be an inode and the map must also
+ * be a **BPF_MAP_TYPE_INODE_STORAGE**.
+ *
+ * Underneath, the value is stored locally at *inode* instead of
+ * the *map*. The *map* is used as the bpf-local-storage
+ * "type". The bpf-local-storage "type" (i.e. the *map*) is
+ * searched against all bpf_local_storage residing at *inode*.
+ *
+ * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be
+ * used such that a new bpf_local_storage will be
+ * created if one does not exist. *value* can be used
+ * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify
+ * the initial value of a bpf_local_storage. If *value* is
+ * **NULL**, the new bpf_local_storage will be zero initialized.
+ * Return
+ * A bpf_local_storage pointer is returned on success.
+ *
+ * **NULL** if not found or there was an error in adding
+ * a new bpf_local_storage.
+ *
+ * int bpf_inode_storage_delete(struct bpf_map *map, void *inode)
+ * Description
+ * Delete a bpf_local_storage from an *inode*.
+ * Return
+ * 0 on success.
+ *
+ * **-ENOENT** if the bpf_local_storage cannot be found.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -3288,7 +3325,9 @@ union bpf_attr {
FN(seq_printf), \
FN(seq_write), \
FN(sk_cgroup_id), \
- FN(sk_ancestor_cgroup_id),
+ FN(sk_ancestor_cgroup_id), \
+ FN(inode_storage_get), \
+ FN(inode_storage_delete),

/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
index 0a1caac2f5f7..bf807cfe3a73 100644
--- a/kernel/bpf/bpf_local_storage.c
+++ b/kernel/bpf/bpf_local_storage.c
@@ -23,6 +23,7 @@ struct bucket {

enum bpf_local_storage_type {
BPF_LOCAL_STORAGE_SK,
+ BPF_LOCAL_STORAGE_INODE,
};

/* Thp map is not the primary owner of a bpf_local_storage_elem.
@@ -94,6 +95,7 @@ struct bpf_local_storage {
*/
union {
struct sock *sk;
+ struct inode *inode;
};
struct rcu_head rcu;
raw_spinlock_t lock; /* Protect adding/removing from the "list" */
@@ -165,6 +167,7 @@ static struct bpf_local_storage_elem *sk_selem_alloc(
static void __unlink_local_storage(struct bpf_local_storage *local_storage,
bool uncharge_omem)
{
+ struct inode *inode;
struct sock *sk;

switch (local_storage->stype) {
@@ -178,6 +181,12 @@ static void __unlink_local_storage(struct bpf_local_storage *local_storage,
RCU_INIT_POINTER(sk->sk_bpf_storage, NULL);
local_storage->sk = NULL;
break;
+ case BPF_LOCAL_STORAGE_INODE:
+ inode = local_storage->inode;
+ /* After this RCU_INIT, sk may be freed and cannot be used */
+ RCU_INIT_POINTER(inode->inode_bpf_storage, NULL);
+ local_storage->inode = NULL;
+ break;
}
}

@@ -339,6 +348,20 @@ sk_storage_lookup(struct sock *sk, struct bpf_map *map, bool cacheit_lockit)
return __local_storage_lookup(sk_storage, smap, cacheit_lockit);
}

+static struct bpf_local_storage_data *inode_storage_lookup(
+ struct inode *inode, struct bpf_map *map, bool cacheit_lockit)
+{
+ struct bpf_local_storage *inode_storage;
+ struct bpf_local_storage_map *smap;
+
+ inode_storage = rcu_dereference(inode->inode_bpf_storage);
+ if (!inode_storage)
+ return NULL;
+
+ smap = (struct bpf_local_storage_map *)map;
+ return __local_storage_lookup(inode_storage, smap, cacheit_lockit);
+}
+
static int check_flags(const struct bpf_local_storage_data *old_sdata,
u64 map_flags)
{
@@ -435,6 +458,33 @@ static int sk_storage_alloc(struct sock *sk,
return err;
}

+static int inode_storage_alloc(struct inode *inode,
+ struct bpf_local_storage_map *smap,
+ struct bpf_local_storage_elem *first_selem)
+{
+ struct bpf_local_storage *curr;
+ int err;
+
+ curr = bpf_local_storage_alloc(smap);
+ if (!curr)
+ return -ENOMEM;
+
+ curr->inode = inode;
+ curr->stype = BPF_LOCAL_STORAGE_INODE;
+
+ __selem_link(curr, first_selem);
+ selem_link_map(smap, first_selem);
+
+ err = publish_local_storage(first_selem,
+ (struct bpf_local_storage **)&inode->inode_bpf_storage, curr);
+ if (err) {
+ kfree(curr);
+ return err;
+ }
+
+ return 0;
+}
+
static int check_update_flags(struct bpf_map *map, u64 map_flags)
{
/* BPF_EXIST and BPF_NOEXIST cannot be both set */
@@ -565,6 +615,109 @@ static struct bpf_local_storage_data *sk_storage_update(struct sock *sk,
return ERR_PTR(err);
}

+static struct bpf_local_storage_data *inode_storage_update(
+ struct inode *inode, struct bpf_map *map, void *value, u64 map_flags)
+{
+ 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;
+
+ err = check_update_flags(map, map_flags);
+ if (err)
+ return ERR_PTR(err);
+
+ smap = (struct bpf_local_storage_map *)map;
+ local_storage = rcu_dereference(inode->inode_bpf_storage);
+
+ if (!local_storage || hlist_empty(&local_storage->list)) {
+ /* Very first elem for this inode */
+ err = check_flags(NULL, map_flags);
+ if (err)
+ return ERR_PTR(err);
+
+ selem = selem_alloc(smap, value);
+ if (!selem)
+ return ERR_PTR(-ENOMEM);
+
+ err = inode_storage_alloc(inode, smap, selem);
+ if (err) {
+ kfree(selem);
+ return ERR_PTR(err);
+ }
+
+ return SDATA(selem);
+ }
+
+ 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 local_storage->lock
+ * and changing the lists.
+ */
+ old_sdata = __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_node(SELEM(old_sdata))) {
+ copy_map_value_locked(map, old_sdata->data,
+ value, false);
+ return old_sdata;
+ }
+ }
+
+ raw_spin_lock_bh(&local_storage->lock);
+
+ /* 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.
+ */
+ err = -EAGAIN;
+ goto unlock_err;
+ }
+
+ old_sdata = __local_storage_lookup(local_storage, smap, false);
+ err = check_flags(old_sdata, map_flags);
+ if (err)
+ goto unlock_err;
+
+ if (old_sdata && (map_flags & BPF_F_LOCK)) {
+ copy_map_value_locked(map, old_sdata->data, value, false);
+ selem = SELEM(old_sdata);
+ goto unlock;
+ }
+
+ selem = selem_alloc(smap, value);
+ if (!selem) {
+ err = -ENOMEM;
+ goto unlock_err;
+ }
+
+ /* First, link the new selem to the map */
+ selem_link_map(smap, selem);
+
+ /* Second, link (and publish) the new selem to sk_storage */
+ __selem_link(local_storage, selem);
+
+ /* Third, remove old selem, SELEM(old_sdata) */
+ if (old_sdata) {
+ selem_unlink_map(SELEM(old_sdata));
+ __selem_unlink(local_storage, SELEM(old_sdata), false);
+ }
+
+unlock:
+ raw_spin_unlock_bh(&local_storage->lock);
+ return SDATA(selem);
+
+unlock_err:
+ 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_local_storage_data *sdata;
@@ -578,6 +731,19 @@ static int sk_storage_delete(struct sock *sk, struct bpf_map *map)
return 0;
}

+static int inode_storage_delete(struct inode *inode, struct bpf_map *map)
+{
+ struct bpf_local_storage_data *sdata;
+
+ sdata = inode_storage_lookup(inode, map, false);
+ if (!sdata)
+ return -ENOENT;
+
+ selem_unlink(SELEM(sdata));
+
+ return 0;
+}
+
/* Called by __sk_destruct() & bpf_sk_storage_clone() */
void bpf_sk_storage_free(struct sock *sk)
{
@@ -617,6 +783,46 @@ void bpf_sk_storage_free(struct sock *sk)
kfree_rcu(sk_storage, rcu);
}

+/* Called by __destroy_inode() */
+void bpf_inode_storage_free(struct inode *inode)
+{
+ struct bpf_local_storage_elem *selem;
+ struct bpf_local_storage *local_storage;
+ bool free_inode_storage = false;
+ struct hlist_node *n;
+
+ rcu_read_lock();
+ local_storage = rcu_dereference(inode->inode_bpf_storage);
+ if (!local_storage) {
+ rcu_read_unlock();
+ return;
+ }
+
+ /* Netiher the bpf_prog nor the bpf-map's syscall
+ * could be modifying the local_storage->list now.
+ * Thus, no elem can be added-to or deleted-from the
+ * local_storage->list by the bpf_prog or by the bpf-map's syscall.
+ *
+ * It is racing with bpf_local_storage_map_free() alone
+ * when unlinking elem from the local_storage->list and
+ * the map's bucket->list.
+ */
+ raw_spin_lock_bh(&local_storage->lock);
+ hlist_for_each_entry_safe(selem, n, &local_storage->list, snode) {
+ /* Always unlink from map before unlinking from
+ * local_storage.
+ */
+ selem_unlink_map(selem);
+ free_inode_storage =
+ __selem_unlink(local_storage, selem, false);
+ }
+ raw_spin_unlock_bh(&local_storage->lock);
+ rcu_read_unlock();
+
+ if (free_inode_storage)
+ kfree_rcu(local_storage, rcu);
+}
+
static void bpf_local_storage_map_free(struct bpf_map *map)
{
struct bpf_local_storage_elem *selem;
@@ -639,7 +845,7 @@ static void bpf_local_storage_map_free(struct bpf_map *map)
*
* The elem of this map can be cleaned up here
* or by bpf_local_storage_free() during the destruction of the
- * owner object. eg. __sk_destruct.
+ * owner object. eg. __sk_destruct or __destroy_inode.
*/
for (i = 0; i < (1U << smap->bucket_log); i++) {
b = &smap->buckets[i];
@@ -789,6 +995,21 @@ static void *bpf_sk_storage_lookup_elem(struct bpf_map *map, void *key)
return ERR_PTR(err);
}

+static void *bpf_inode_storage_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_local_storage_data *sdata;
+ struct inode *inode;
+ int err = -EINVAL;
+
+ inode = *(struct inode **)(key);
+ if (inode) {
+ sdata = inode_storage_lookup(inode, map, true);
+ return sdata ? sdata->data : NULL;
+ }
+
+ return ERR_PTR(err);
+}
+
static int bpf_sk_storage_update_elem(struct bpf_map *map, void *key,
void *value, u64 map_flags)
{
@@ -808,6 +1029,22 @@ static int bpf_sk_storage_update_elem(struct bpf_map *map, void *key,
return err;
}

+static int bpf_inode_storage_update_elem(struct bpf_map *map, void *key,
+ void *value, u64 map_flags)
+{
+ struct bpf_local_storage_data *sdata;
+ struct inode *inode;
+ int err = -EINVAL;
+
+ inode = *(struct inode **)(key);
+ if (inode) {
+ sdata = inode_storage_update(inode, map, value,
+ map_flags);
+ return PTR_ERR_OR_ZERO(sdata);
+ }
+ return err;
+}
+
static int bpf_sk_storage_delete_elem(struct bpf_map *map, void *key)
{
struct socket *sock;
@@ -823,6 +1060,18 @@ static int bpf_sk_storage_delete_elem(struct bpf_map *map, void *key)
return err;
}

+static int bpf_inode_storage_delete_elem(struct bpf_map *map, void *key)
+{
+ struct inode *inode;
+ int err = -EINVAL;
+
+ inode = *(struct inode **)(key);
+ if (inode)
+ err = inode_storage_delete(inode, map);
+
+ return err;
+}
+
static struct bpf_local_storage_elem *
bpf_sk_storage_clone_elem(struct sock *newsk,
struct bpf_local_storage_map *smap,
@@ -944,6 +1193,29 @@ BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk,
return (unsigned long)NULL;
}

+BPF_CALL_4(bpf_inode_storage_get, struct bpf_map *, map, struct inode *, inode,
+ void *, value, u64, flags)
+{
+ struct bpf_local_storage_data *sdata;
+
+ if (flags > BPF_LOCAL_STORAGE_GET_F_CREATE)
+ return (unsigned long)NULL;
+
+ sdata = inode_storage_lookup(inode, map, true);
+ if (sdata)
+ return (unsigned long)sdata->data;
+
+ if (flags == BPF_LOCAL_STORAGE_GET_F_CREATE &&
+ atomic_inc_not_zero(&inode->i_count)) {
+ sdata = inode_storage_update(inode, map, value, BPF_NOEXIST);
+ iput(inode);
+ return IS_ERR(sdata) ?
+ (unsigned long)NULL : (unsigned long)sdata->data;
+ }
+
+ return (unsigned long)NULL;
+}
+
BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk)
{
if (refcount_inc_not_zero(&sk->sk_refcnt)) {
@@ -957,6 +1229,20 @@ BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk)
return -ENOENT;
}

+BPF_CALL_2(bpf_inode_storage_delete,
+ struct bpf_map *, map, struct inode *, inode)
+{
+ int err;
+
+ if (atomic_inc_not_zero(&inode->i_count)) {
+ err = inode_storage_delete(inode, map);
+ iput(inode);
+ return err;
+ }
+
+ return inode_storage_delete(inode, map);
+}
+
const struct bpf_map_ops sk_storage_map_ops = {
.map_alloc_check = bpf_local_storage_map_alloc_check,
.map_alloc = bpf_local_storage_map_alloc,
@@ -968,6 +1254,17 @@ const struct bpf_map_ops sk_storage_map_ops = {
.map_check_btf = bpf_local_storage_map_check_btf,
};

+const struct bpf_map_ops inode_storage_map_ops = {
+ .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_inode_storage_lookup_elem,
+ .map_update_elem = bpf_inode_storage_update_elem,
+ .map_delete_elem = bpf_inode_storage_delete_elem,
+ .map_check_btf = bpf_local_storage_map_check_btf,
+};
+
const struct bpf_func_proto bpf_sk_storage_get_proto = {
.func = bpf_sk_storage_get,
.gpl_only = false,
@@ -986,6 +1283,28 @@ const struct bpf_func_proto bpf_sk_storage_delete_proto = {
.arg2_type = ARG_PTR_TO_SOCKET,
};

+static int bpf_inode_storage_get_btf_ids[4];
+const struct bpf_func_proto bpf_inode_storage_get_proto = {
+ .func = bpf_inode_storage_get,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
+ .arg1_type = ARG_CONST_MAP_PTR,
+ .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
+ .arg4_type = ARG_ANYTHING,
+ .btf_id = bpf_inode_storage_get_btf_ids,
+};
+
+static int bpf_inode_storage_delete_btf_ids[2];
+const struct bpf_func_proto bpf_inode_storage_delete_proto = {
+ .func = bpf_sk_storage_delete,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_CONST_MAP_PTR,
+ .arg2_type = ARG_PTR_TO_BTF_ID,
+ .btf_id = bpf_inode_storage_delete_btf_ids,
+};
+
struct bpf_sk_storage_diag {
u32 nr_maps;
struct bpf_map *maps[];
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index d13b804ff045..60407c2d8fbd 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -765,7 +765,8 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
if (map->map_type != BPF_MAP_TYPE_HASH &&
map->map_type != BPF_MAP_TYPE_ARRAY &&
map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
- map->map_type != BPF_MAP_TYPE_SK_STORAGE)
+ map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
+ map->map_type != BPF_MAP_TYPE_INODE_STORAGE)
return -ENOTSUPP;
if (map->spin_lock_off + sizeof(struct bpf_spin_lock) >
map->value_size) {
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d2e27dba4ac6..ff90e85e243c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4000,6 +4000,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
func_id != BPF_FUNC_sk_storage_delete)
goto error;
break;
+ case BPF_MAP_TYPE_INODE_STORAGE:
+ if (func_id != BPF_FUNC_inode_storage_get &&
+ func_id != BPF_FUNC_inode_storage_delete)
+ goto error;
+ break;
default:
break;
}
@@ -4073,6 +4078,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
if (map->map_type != BPF_MAP_TYPE_SK_STORAGE)
goto error;
break;
+ case BPF_FUNC_inode_storage_get:
+ case BPF_FUNC_inode_storage_delete:
+ if (map->map_type != BPF_MAP_TYPE_INODE_STORAGE)
+ goto error;
+ break;
default:
break;
}
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index c5fac8068ba1..e8fbafb3e87b 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -49,6 +49,7 @@ const char * const map_type_name[] = {
[BPF_MAP_TYPE_STACK] = "stack",
[BPF_MAP_TYPE_SK_STORAGE] = "sk_storage",
[BPF_MAP_TYPE_STRUCT_OPS] = "struct_ops",
+ [BPF_MAP_TYPE_INODE_STORAGE] = "inode_storage",
};

const size_t map_type_name_size = ARRAY_SIZE(map_type_name);
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 4a202eea15c0..410fb2e5fdd4 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -147,6 +147,7 @@ enum bpf_map_type {
BPF_MAP_TYPE_SK_STORAGE,
BPF_MAP_TYPE_DEVMAP_HASH,
BPF_MAP_TYPE_STRUCT_OPS,
+ BPF_MAP_TYPE_INODE_STORAGE,
};

/* Note that tracing related programs such as
@@ -3157,6 +3158,42 @@ union bpf_attr {
* **bpf_sk_cgroup_id**\ ().
* Return
* The id is returned or 0 in case the id could not be retrieved.
+ *
+ * void *bpf_inode_storage_get(struct bpf_map *map, void *inode, void *value, u64 flags)
+ * Description
+ * Get a bpf_local_storage from an *inode*.
+ *
+ * Logically, it could be thought of as getting the value from
+ * a *map* with *inode* as the **key**. From this
+ * perspective, the usage is not much different from
+ * **bpf_map_lookup_elem**\ (*map*, **&**\ *inode*) except this
+ * helper enforces the key must be an inode and the map must also
+ * be a **BPF_MAP_TYPE_INODE_STORAGE**.
+ *
+ * Underneath, the value is stored locally at *inode* instead of
+ * the *map*. The *map* is used as the bpf-local-storage
+ * "type". The bpf-local-storage "type" (i.e. the *map*) is
+ * searched against all bpf_local_storage residing at *inode*.
+ *
+ * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be
+ * used such that a new bpf_local_storage will be
+ * created if one does not exist. *value* can be used
+ * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify
+ * the initial value of a bpf_local_storage. If *value* is
+ * **NULL**, the new bpf_local_storage will be zero initialized.
+ * Return
+ * A bpf_local_storage pointer is returned on success.
+ *
+ * **NULL** if not found or there was an error in adding
+ * a new bpf_local_storage.
+ *
+ * int bpf_inode_storage_delete(struct bpf_map *map, void *inode)
+ * Description
+ * Delete a bpf_local_storage from an *inode*.
+ * Return
+ * 0 on success.
+ *
+ * **-ENOENT** if the bpf_local_storage cannot be found.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -3288,7 +3325,9 @@ union bpf_attr {
FN(seq_printf), \
FN(seq_write), \
FN(sk_cgroup_id), \
- FN(sk_ancestor_cgroup_id),
+ FN(sk_ancestor_cgroup_id), \
+ FN(inode_storage_get), \
+ FN(inode_storage_delete),

/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c
index 2c92059c0c90..795d7938ab56 100644
--- a/tools/lib/bpf/libbpf_probes.c
+++ b/tools/lib/bpf/libbpf_probes.c
@@ -170,7 +170,7 @@ int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
return btf_fd;
}

-static int load_sk_storage_btf(void)
+static int load_local_storage_btf(void)
{
const char strs[] = "\0bpf_spin_lock\0val\0cnt\0l";
/* struct bpf_spin_lock {
@@ -229,12 +229,13 @@ bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex)
key_size = 0;
break;
case BPF_MAP_TYPE_SK_STORAGE:
+ case BPF_MAP_TYPE_INODE_STORAGE:
btf_key_type_id = 1;
btf_value_type_id = 3;
value_size = 8;
max_entries = 0;
map_flags = BPF_F_NO_PREALLOC;
- btf_fd = load_sk_storage_btf();
+ btf_fd = load_local_storage_btf();
if (btf_fd < 0)
return false;
break;
--
2.27.0.rc0.183.gde8f92d652-goog
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