diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2025-04-17 17:03:48 -0700 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-04-24 09:29:56 +0200 |
| commit | 5720a328c3e9802af48dd216c1c7eb0e91b61b6c (patch) | |
| tree | 149643f66df8fbf8310c6b4be47cbad4311a5c3b | |
| parent | c4837b9853e5a7fa70122b7760f0f26147b08a57 (diff) | |
ipv6: Preallocate rt->fib6_nh->rt6i_pcpu in ip6_route_info_create().
ip6_route_info_create_nh() will be called under RCU.
Then, fib6_nh_init() is also under RCU, but per-cpu memory allocation
is very likely to fail with GFP_ATOMIC while bulk-adding IPv6 routes
and we would see a bunch of this message in dmesg.
percpu: allocation failed, size=8 align=8 atomic=1, atomic alloc failed, no space left
percpu: allocation failed, size=8 align=8 atomic=1, atomic alloc failed, no space left
Let's preallocate rt->fib6_nh->rt6i_pcpu in ip6_route_info_create().
If something fails before the original memory allocation in
fib6_nh_init(), ip6_route_info_create_nh() calls fib6_info_release(),
which releases the preallocated per-cpu memory.
Note that rt->fib6_nh->rt6i_pcpu is not preallocated when called via
ipv6_stub, so we still need alloc_percpu_gfp() in fib6_nh_init().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250418000443.43734-8-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | net/ipv6/route.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index bba35cb2dc25..1155cb017343 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -3665,10 +3665,12 @@ int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, goto out; pcpu_alloc: - fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags); if (!fib6_nh->rt6i_pcpu) { - err = -ENOMEM; - goto out; + fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags); + if (!fib6_nh->rt6i_pcpu) { + err = -ENOMEM; + goto out; + } } fib6_nh->fib_nh_dev = dev; @@ -3728,6 +3730,15 @@ void fib6_nh_release_dsts(struct fib6_nh *fib6_nh) } } +static int fib6_nh_prealloc_percpu(struct fib6_nh *fib6_nh, gfp_t gfp_flags) +{ + fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags); + if (!fib6_nh->rt6i_pcpu) + return -ENOMEM; + + return 0; +} + static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg, gfp_t gfp_flags, struct netlink_ext_ack *extack) @@ -3765,6 +3776,12 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg, goto free; } + if (!cfg->fc_nh_id) { + err = fib6_nh_prealloc_percpu(&rt->fib6_nh[0], gfp_flags); + if (err) + goto free_metrics; + } + if (cfg->fc_flags & RTF_ADDRCONF) rt->dst_nocount = true; @@ -3789,6 +3806,8 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg, rt->fib6_src.plen = cfg->fc_src_len; #endif return rt; +free_metrics: + ip_fib_metrics_put(rt->fib6_metrics); free: kfree(rt); err: |