diff mbox series

[bpf-next,02/13] bpf: refactor map_update_elem()

Message ID 20190829064504.2750444-1-yhs@fb.com
State Changes Requested
Delegated to: BPF Maintainers
Headers show
Series bpf: adding map batch processing support | expand

Commit Message

Yonghong Song Aug. 29, 2019, 6:45 a.m. UTC 
Refactor function map_update_elem() by creating a
helper function bpf_map_update_elem() which will be
used later by batched map update operation.

Also reuse function bpf_map_value_size()
in map_update_elem().

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 kernel/bpf/syscall.c | 113 ++++++++++++++++++++++---------------------
 1 file changed, 57 insertions(+), 56 deletions(-)

Comments

Song Liu Aug. 29, 2019, 11:37 p.m. UTC | #1 
> On Aug 28, 2019, at 11:45 PM, Yonghong Song <yhs@fb.com> wrote:
> 
> Refactor function map_update_elem() by creating a
> helper function bpf_map_update_elem() which will be
> used later by batched map update operation.
> 
> Also reuse function bpf_map_value_size()
> in map_update_elem().
> 
> Signed-off-by: Yonghong Song <yhs@fb.com>

Acked-by: Song Liu <songliubraving@fb.com>
diff mbox series

Patch

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 211e0bc667bd..3caa0ab3d30d 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -878,6 +878,61 @@  static void maybe_wait_bpf_programs(struct bpf_map *map)
 		synchronize_rcu();
 }
 
+static int bpf_map_update_elem(struct bpf_map *map, void *key, void *value,
+			       struct fd *f, __u64 flags) {
+	int err;
+
+	/* Need to create a kthread, thus must support schedule */
+	if (bpf_map_is_dev_bound(map)) {
+		return bpf_map_offload_update_elem(map, key, value, flags);
+	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
+		   map->map_type == BPF_MAP_TYPE_SOCKHASH ||
+		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
+		return map->ops->map_update_elem(map, key, value, flags);
+	}
+
+	/* must increment bpf_prog_active to avoid kprobe+bpf triggering from
+	 * inside bpf map update or delete otherwise deadlocks are possible
+	 */
+	preempt_disable();
+	__this_cpu_inc(bpf_prog_active);
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
+		err = bpf_percpu_hash_update(map, key, value, flags);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+		err = bpf_percpu_array_update(map, key, value, flags);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
+		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, f->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, f->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,
+							 flags);
+	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
+		   map->map_type == BPF_MAP_TYPE_STACK) {
+		err = map->ops->map_push_elem(map, value, flags);
+	} else {
+		rcu_read_lock();
+		err = map->ops->map_update_elem(map, key, value, flags);
+		rcu_read_unlock();
+	}
+	__this_cpu_dec(bpf_prog_active);
+	preempt_enable();
+	maybe_wait_bpf_programs(map);
+
+	return err;
+}
+
 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
 
 static int map_update_elem(union bpf_attr *attr)
@@ -915,13 +970,7 @@  static int map_update_elem(union bpf_attr *attr)
 		goto err_put;
 	}
 
-	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
-	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
-	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
-	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
-		value_size = round_up(map->value_size, 8) * num_possible_cpus();
-	else
-		value_size = map->value_size;
+	value_size = bpf_map_value_size(map);
 
 	err = -ENOMEM;
 	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
@@ -932,56 +981,8 @@  static int map_update_elem(union bpf_attr *attr)
 	if (copy_from_user(value, uvalue, value_size) != 0)
 		goto free_value;
 
-	/* Need to create a kthread, thus must support schedule */
-	if (bpf_map_is_dev_bound(map)) {
-		err = bpf_map_offload_update_elem(map, key, value, attr->flags);
-		goto out;
-	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
-		   map->map_type == BPF_MAP_TYPE_SOCKHASH ||
-		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
-		err = map->ops->map_update_elem(map, key, value, attr->flags);
-		goto out;
-	}
+	err = bpf_map_update_elem(map, key, value, &f, attr->flags);
 
-	/* must increment bpf_prog_active to avoid kprobe+bpf triggering from
-	 * inside bpf map update or delete otherwise deadlocks are possible
-	 */
-	preempt_disable();
-	__this_cpu_inc(bpf_prog_active);
-	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
-	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
-		err = bpf_percpu_hash_update(map, key, value, attr->flags);
-	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
-		err = bpf_percpu_array_update(map, key, value, attr->flags);
-	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
-		err = bpf_percpu_cgroup_storage_update(map, key, value,
-						       attr->flags);
-	} else if (IS_FD_ARRAY(map)) {
-		rcu_read_lock();
-		err = bpf_fd_array_map_update_elem(map, f.file, key, value,
-						   attr->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, f.file, key, value,
-						  attr->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,
-							 attr->flags);
-	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
-		   map->map_type == BPF_MAP_TYPE_STACK) {
-		err = map->ops->map_push_elem(map, value, attr->flags);
-	} else {
-		rcu_read_lock();
-		err = map->ops->map_update_elem(map, key, value, attr->flags);
-		rcu_read_unlock();
-	}
-	__this_cpu_dec(bpf_prog_active);
-	preempt_enable();
-	maybe_wait_bpf_programs(map);
-out:
 free_value:
 	kfree(value);
 free_key: