mirror of
https://github.com/torvalds/linux
synced 2024-10-14 23:39:09 +00:00
bpf: Reduce the scope of rcu_read_lock when updating fd map
There is no rcu-read-lock requirement for ops->map_fd_get_ptr() or ops->map_fd_put_ptr(), so doesn't use rcu-read-lock for these two callbacks. For bpf_fd_array_map_update_elem(), accessing array->ptrs doesn't need rcu-read-lock because array->ptrs must still be allocated. For bpf_fd_htab_map_update_elem(), htab_map_update_elem() only requires rcu-read-lock to be held to avoid the WARN_ON_ONCE(), so only use rcu_read_lock() during the invocation of htab_map_update_elem(). Acked-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20231214043010.3458072-2-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
parent
2a0c6b41ee
commit
8f82583f95
|
@ -2523,7 +2523,13 @@ int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file,
|
|||
if (IS_ERR(ptr))
|
||||
return PTR_ERR(ptr);
|
||||
|
||||
/* The htab bucket lock is always held during update operations in fd
|
||||
* htab map, and the following rcu_read_lock() is only used to avoid
|
||||
* the WARN_ON_ONCE in htab_map_update_elem().
|
||||
*/
|
||||
rcu_read_lock();
|
||||
ret = htab_map_update_elem(map, key, &ptr, map_flags);
|
||||
rcu_read_unlock();
|
||||
if (ret)
|
||||
map->ops->map_fd_put_ptr(map, ptr, false);
|
||||
|
||||
|
|
|
@ -184,15 +184,11 @@ static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
|
|||
err = bpf_percpu_cgroup_storage_update(map, key, value,
|
||||
flags);
|
||||
} else if (IS_FD_ARRAY(map)) {
|
||||
rcu_read_lock();
|
||||
err = bpf_fd_array_map_update_elem(map, map_file, key, value,
|
||||
flags);
|
||||
rcu_read_unlock();
|
||||
} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
|
||||
rcu_read_lock();
|
||||
err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
|
||||
flags);
|
||||
rcu_read_unlock();
|
||||
} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
|
||||
/* rcu_read_lock() is not needed */
|
||||
err = bpf_fd_reuseport_array_update_elem(map, key, value,
|
||||
|
|
Loading…
Reference in a new issue