diff mbox series

[v4,net,1/3] net: Add net_passive_inc() and net_passive_dec().

Message ID 20250212064206.18159-2-kuniyu@amazon.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series net: Fix race of rtnl_net_lock(dev_net(dev)). | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 40 this patch: 40
netdev/build_tools success Errors and warnings before: 26 (+1) this patch: 26 (+1)
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/build_clang success Errors and warnings before: 7211 this patch: 7211
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: 4267 this patch: 4267
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 57 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 3 this patch: 3
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2025-02-12--09-00 (tests: 889)

Commit Message

Kuniyuki Iwashima Feb. 12, 2025, 6:42 a.m. UTC 
net_drop_ns() is NULL when CONFIG_NET_NS is disabled.

The next patch introduces a function that increments
and decrements net->passive.

As a prep, let's rename and export net_free() to
net_passive_dec() and add net_passive_inc().

Suggested-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/netdev/CANn89i+oUCt2VGvrbrweniTendZFEh+nwS=uonc004-aPkWy-Q@mail.gmail.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 include/net/net_namespace.h | 11 +++++++++++
 net/core/net_namespace.c    |  8 ++++----
 2 files changed, 15 insertions(+), 4 deletions(-)

Comments

Eric Dumazet Feb. 12, 2025, 1:52 p.m. UTC | #1 
On Wed, Feb 12, 2025 at 7:42 AM Kuniyuki Iwashima <kuniyu@amazon.com> wrote:
>
> net_drop_ns() is NULL when CONFIG_NET_NS is disabled.
>
> The next patch introduces a function that increments
> and decrements net->passive.
>
> As a prep, let's rename and export net_free() to
> net_passive_dec() and add net_passive_inc().
>
> Suggested-by: Eric Dumazet <edumazet@google.com>
> Link: https://lore.kernel.org/netdev/CANn89i+oUCt2VGvrbrweniTendZFEh+nwS=uonc004-aPkWy-Q@mail.gmail.com/
> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
> ---

Reviewed-by: Eric Dumazet <edumazet@google.com>
diff mbox series

Patch

diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 7ba1402ca779..f467a66abc6b 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -297,6 +297,7 @@  static inline int check_net(const struct net *net)
 }
 
 void net_drop_ns(void *);
+void net_passive_dec(struct net *net);
 
 #else
 
@@ -326,8 +327,18 @@  static inline int check_net(const struct net *net)
 }
 
 #define net_drop_ns NULL
+
+static inline void net_passive_dec(struct net *net)
+{
+	refcount_dec(&net->passive);
+}
 #endif
 
+static inline void net_passive_inc(struct net *net)
+{
+	refcount_inc(&net->passive);
+}
+
 /* Returns true if the netns initialization is completed successfully */
 static inline bool net_initialized(const struct net *net)
 {
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index cb39a12b2f82..4303f2a49262 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -464,7 +464,7 @@  static void net_complete_free(void)
 
 }
 
-static void net_free(struct net *net)
+void net_passive_dec(struct net *net)
 {
 	if (refcount_dec_and_test(&net->passive)) {
 		kfree(rcu_access_pointer(net->gen));
@@ -482,7 +482,7 @@  void net_drop_ns(void *p)
 	struct net *net = (struct net *)p;
 
 	if (net)
-		net_free(net);
+		net_passive_dec(net);
 }
 
 struct net *copy_net_ns(unsigned long flags,
@@ -523,7 +523,7 @@  struct net *copy_net_ns(unsigned long flags,
 		key_remove_domain(net->key_domain);
 #endif
 		put_user_ns(user_ns);
-		net_free(net);
+		net_passive_dec(net);
 dec_ucounts:
 		dec_net_namespaces(ucounts);
 		return ERR_PTR(rv);
@@ -672,7 +672,7 @@  static void cleanup_net(struct work_struct *work)
 		key_remove_domain(net->key_domain);
 #endif
 		put_user_ns(net->user_ns);
-		net_free(net);
+		net_passive_dec(net);
 	}
 	cleanup_net_task = NULL;
 }