From: Amery Hung <ameryhung@gmail.com>
To: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org, alexei.starovoitov@gmail.com,
andrii@kernel.org, daniel@iogearbox.net, memxor@gmail.com,
martin.lau@kernel.org, kpsingh@kernel.org,
yonghong.song@linux.dev, song@kernel.org, haoluo@google.com,
ameryhung@gmail.com, kernel-team@meta.com
Subject: [RFC PATCH bpf-next v2 04/12] bpf: Open code bpf_selem_unlink_storage in bpf_selem_unlink
Date: Thu, 2 Oct 2025 15:53:43 -0700 [thread overview]
Message-ID: <20251002225356.1505480-5-ameryhung@gmail.com> (raw)
In-Reply-To: <20251002225356.1505480-1-ameryhung@gmail.com>
To prepare for changing bpf_local_storage::lock to rqspinlock, open code
bpf_selem_unlink_storage() in the only caller, bpf_selem_unlink(), since
unlink_map and unlink_storage must be done together after all the
necessary locks are acquired.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
---
kernel/bpf/bpf_local_storage.c | 71 ++++++++++++++++------------------
1 file changed, 33 insertions(+), 38 deletions(-)
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
index 682409fb22a2..9c2b041ae9ca 100644
--- a/kernel/bpf/bpf_local_storage.c
+++ b/kernel/bpf/bpf_local_storage.c
@@ -371,37 +371,6 @@ static bool check_storage_bpf_ma(struct bpf_local_storage *local_storage,
return selem_smap->bpf_ma;
}
-static void bpf_selem_unlink_storage(struct bpf_local_storage_elem *selem,
- bool reuse_now)
-{
- struct bpf_local_storage_map *storage_smap;
- struct bpf_local_storage *local_storage;
- bool bpf_ma, free_local_storage = false;
- HLIST_HEAD(selem_free_list);
- unsigned long flags;
-
- if (unlikely(!selem_linked_to_storage_lockless(selem)))
- /* selem has already been unlinked from sk */
- return;
-
- local_storage = rcu_dereference_check(selem->local_storage,
- bpf_rcu_lock_held());
- storage_smap = rcu_dereference_check(local_storage->smap,
- bpf_rcu_lock_held());
- bpf_ma = check_storage_bpf_ma(local_storage, storage_smap, selem);
-
- raw_spin_lock_irqsave(&local_storage->lock, flags);
- if (likely(selem_linked_to_storage(selem)))
- free_local_storage = bpf_selem_unlink_storage_nolock(
- local_storage, selem, true, &selem_free_list);
- raw_spin_unlock_irqrestore(&local_storage->lock, flags);
-
- bpf_selem_free_list(&selem_free_list, reuse_now);
-
- if (free_local_storage)
- bpf_local_storage_free(local_storage, storage_smap, bpf_ma, reuse_now);
-}
-
void bpf_selem_link_storage_nolock(struct bpf_local_storage *local_storage,
struct bpf_local_storage_elem *selem)
{
@@ -466,17 +435,43 @@ static void bpf_selem_link_map_nolock(struct bpf_local_storage_map *smap,
void bpf_selem_unlink(struct bpf_local_storage_elem *selem, bool reuse_now)
{
+ struct bpf_local_storage_map *storage_smap;
+ struct bpf_local_storage *local_storage;
+ bool bpf_ma, free_local_storage = false;
+ HLIST_HEAD(selem_free_list);
+ unsigned long flags;
int err;
- /* Always unlink from map before unlinking from local_storage
- * because selem will be freed after successfully unlinked from
- * the local_storage.
- */
- err = bpf_selem_unlink_map(selem);
- if (err)
+ if (unlikely(!selem_linked_to_storage_lockless(selem)))
+ /* selem has already been unlinked from sk */
return;
- bpf_selem_unlink_storage(selem, reuse_now);
+ local_storage = rcu_dereference_check(selem->local_storage,
+ bpf_rcu_lock_held());
+ storage_smap = rcu_dereference_check(local_storage->smap,
+ bpf_rcu_lock_held());
+ bpf_ma = check_storage_bpf_ma(local_storage, storage_smap, selem);
+
+ raw_spin_lock_irqsave(&local_storage->lock, flags);
+ if (likely(selem_linked_to_storage(selem))) {
+ /* Always unlink from map before unlinking from local_storage
+ * because selem will be freed after successfully unlinked from
+ * the local_storage.
+ */
+ err = bpf_selem_unlink_map(selem);
+ if (err)
+ goto out;
+
+ free_local_storage = bpf_selem_unlink_storage_nolock(
+ local_storage, selem, true, &selem_free_list);
+ }
+out:
+ raw_spin_unlock_irqrestore(&local_storage->lock, flags);
+
+ bpf_selem_free_list(&selem_free_list, reuse_now);
+
+ if (free_local_storage)
+ bpf_local_storage_free(local_storage, storage_smap, bpf_ma, reuse_now);
}
void __bpf_local_storage_insert_cache(struct bpf_local_storage *local_storage,
--
2.47.3
next prev parent reply other threads:[~2025-10-02 22:54 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-02 22:53 [RFC PATCH bpf-next v2 00/12] Remove task and cgroup local storage percpu counters Amery Hung
2025-10-02 22:53 ` [RFC PATCH bpf-next v2 01/12] bpf: Select bpf_local_storage_map_bucket based on bpf_local_storage Amery Hung
2025-10-02 22:53 ` [RFC PATCH bpf-next v2 02/12] bpf: Convert bpf_selem_unlink_map to failable Amery Hung
2025-10-02 22:53 ` [RFC PATCH bpf-next v2 03/12] bpf: Convert bpf_selem_link_map " Amery Hung
2025-10-02 22:53 ` Amery Hung [this message]
2025-10-02 22:53 ` [RFC PATCH bpf-next v2 05/12] bpf: Convert bpf_selem_unlink " Amery Hung
2025-10-02 22:53 ` [RFC PATCH bpf-next v2 06/12] bpf: Change local_storage->lock and b->lock to rqspinlock Amery Hung
2025-10-02 23:37 ` Alexei Starovoitov
2025-10-03 22:03 ` Amery Hung
2025-10-06 17:58 ` Alexei Starovoitov
2025-10-06 20:19 ` Martin KaFai Lau
2025-10-02 22:53 ` [RFC PATCH bpf-next v2 07/12] bpf: Remove task local storage percpu counter Amery Hung
2025-10-02 22:53 ` [RFC PATCH bpf-next v2 08/12] bpf: Remove cgroup " Amery Hung
2025-10-02 22:53 ` [RFC PATCH bpf-next v2 09/12] bpf: Remove unused percpu counter from bpf_local_storage_map_free Amery Hung
2025-10-02 22:53 ` [RFC PATCH bpf-next v2 10/12] selftests/bpf: Update task_local_storage/recursion test Amery Hung
2025-10-02 22:53 ` [RFC PATCH bpf-next v2 11/12] selftests/bpf: Remove test_task_storage_map_stress_lookup Amery Hung
2025-10-02 22:53 ` [RFC PATCH bpf-next v2 12/12] selftests/bpf: Choose another percpu variable in bpf for btf_dump test Amery Hung
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