[PATCH bpf-next v3 03/16] bpf: Open code bpf_selem_unlink_storage in bpf_selem_unlink
From: Amery Hung <hidden>
Date: 2025-12-18 17:56:35
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
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 <redacted> --- kernel/bpf/bpf_local_storage.c | 63 ++++++++++++++++------------------ 1 file changed, 29 insertions(+), 34 deletions(-)
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
index 94a20c147bc7..0e3fa5fbaaf3 100644
--- a/kernel/bpf/bpf_local_storage.c
+++ b/kernel/bpf/bpf_local_storage.c@@ -313,33 +313,6 @@ static bool bpf_selem_unlink_storage_nolock(struct bpf_local_storage *local_stor return free_local_storage; } -static void bpf_selem_unlink_storage(struct bpf_local_storage_elem *selem, - bool reuse_now) -{ - struct bpf_local_storage *local_storage; - bool 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()); - - 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, &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, reuse_now); -} - void bpf_selem_link_storage_nolock(struct bpf_local_storage *local_storage, struct bpf_local_storage_elem *selem) {
@@ -396,17 +369,39 @@ 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 *local_storage; + bool 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()); + + 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, &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, reuse_now); } void __bpf_local_storage_insert_cache(struct bpf_local_storage *local_storage,
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2.47.3