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| author | Hou Tao <houtao1@huawei.com> | 2025-01-08 02:07:18 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-01-09 03:06:36 +0100 |
| commit | e319cdc8956645b6e29a3809924647953500b7e1 (patch) | |
| tree | 9d10a940ef064a5e0707ac12073237df8d0b11cc /kernel | |
| parent | bpf: Remove migrate_{disable|enable} from bpf_task_storage_lock helpers (diff) | |
| download | linux-e319cdc8956645b6e29a3809924647953500b7e1.tar.xz linux-e319cdc8956645b6e29a3809924647953500b7e1.zip | |
bpf: Disable migration when destroying inode storage
When destroying inode storage, it invokes bpf_local_storage_destroy() to
remove all storage elements saved in the inode storage. The destroy
procedure will call bpf_selem_free() to free the element, and
bpf_selem_free() calls bpf_obj_free_fields() to free the special fields
in map value (e.g., kptr). Since kptrs may be allocated from bpf memory
allocator, migrate_{disable|enable} pairs are necessary for the freeing
of these kptrs.
To simplify reasoning about when migrate_disable() is needed for the
freeing of these dynamically-allocated kptrs, let the caller to
guarantee migration is disabled before invoking bpf_obj_free_fields().
Therefore, the patch adds migrate_{disable|enable} pair in
bpf_inode_storage_free(). The migrate_{disable|enable} pairs in the
underlying implementation of bpf_obj_free_fields() will be removed by
the following patch.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250108010728.207536-7-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/bpf_inode_storage.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c index a51c82dee1bd..15a3eb9b02d9 100644 --- a/kernel/bpf/bpf_inode_storage.c +++ b/kernel/bpf/bpf_inode_storage.c @@ -62,16 +62,17 @@ void bpf_inode_storage_free(struct inode *inode) if (!bsb) return; + migrate_disable(); rcu_read_lock(); local_storage = rcu_dereference(bsb->storage); - if (!local_storage) { - rcu_read_unlock(); - return; - } + if (!local_storage) + goto out; bpf_local_storage_destroy(local_storage); +out: rcu_read_unlock(); + migrate_enable(); } static void *bpf_fd_inode_storage_lookup_elem(struct bpf_map *map, void *key) |