From: Shaohua Li <shli@fb.com>
Date: Tue, 27 Mar 2018 11:53:21 -0700
Subject: bpf: follow idr code convention
Patch-mainline: v4.17-rc1
Git-commit: b76354cdfefb68bc017065850a34d486887a4f7b
References: bsc#1109837
Generally we do a preload before doing idr allocation. This also help
improve the allocation success rate in memory pressure.
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
kernel/bpf/syscall.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -203,11 +203,13 @@ static int bpf_map_alloc_id(struct bpf_m
{
int id;
+ idr_preload(GFP_KERNEL);
spin_lock_bh(&map_idr_lock);
id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
if (id > 0)
map->id = id;
spin_unlock_bh(&map_idr_lock);
+ idr_preload_end();
if (WARN_ON_ONCE(!id))
return -ENOSPC;
@@ -927,11 +929,13 @@ static int bpf_prog_alloc_id(struct bpf_
{
int id;
+ idr_preload(GFP_KERNEL);
spin_lock_bh(&prog_idr_lock);
id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
if (id > 0)
prog->aux->id = id;
spin_unlock_bh(&prog_idr_lock);
+ idr_preload_end();
/* id is in [1, INT_MAX) */
if (WARN_ON_ONCE(!id))