diff mbox series

[v3,net-next,08/15] ipv6: Preallocate nhc_pcpu_rth_output in ip6_route_info_create().

Message ID 20250418000443.43734-9-kuniyu@amazon.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series ipv6: No RTNL for IPv6 routing table. | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
netdev/checkpatch warning WARNING: line length of 82 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2025-04-18--09-00 (tests: 916)

Commit Message

Kuniyuki Iwashima April 18, 2025, 12:03 a.m. UTC 
ip6_route_info_create_nh() will be called under RCU.

It calls fib_nh_common_init() and allocates nhc->nhc_pcpu_rth_output.

As with the reason for rt->fib6_nh->rt6i_pcpu, we want to avoid
GFP_ATOMIC allocation for nhc->nhc_pcpu_rth_output under RCU.

Let's preallocate it in ip6_route_info_create().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 net/ipv4/fib_semantics.c | 10 ++++++----
 net/ipv6/route.c         |  9 +++++++++
 2 files changed, 15 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index f68bb9e34c34..5326f1501af0 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -617,10 +617,12 @@  int fib_nh_common_init(struct net *net, struct fib_nh_common *nhc,
 {
 	int err;
 
-	nhc->nhc_pcpu_rth_output = alloc_percpu_gfp(struct rtable __rcu *,
-						    gfp_flags);
-	if (!nhc->nhc_pcpu_rth_output)
-		return -ENOMEM;
+	if (!nhc->nhc_pcpu_rth_output) {
+		nhc->nhc_pcpu_rth_output = alloc_percpu_gfp(struct rtable __rcu *,
+							    gfp_flags);
+		if (!nhc->nhc_pcpu_rth_output)
+			return -ENOMEM;
+	}
 
 	if (encap) {
 		struct lwtunnel_state *lwtstate;
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index b0ddb73c732e..ea755027cf61 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3731,10 +3731,19 @@  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)
 {
+	struct fib_nh_common *nhc = &fib6_nh->nh_common;
+
 	fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
 	if (!fib6_nh->rt6i_pcpu)
 		return -ENOMEM;
 
+	nhc->nhc_pcpu_rth_output = alloc_percpu_gfp(struct rtable __rcu *,
+						    gfp_flags);
+	if (!nhc->nhc_pcpu_rth_output) {
+		free_percpu(fib6_nh->rt6i_pcpu);
+		return -ENOMEM;
+	}
+
 	return 0;
 }