diff mbox series

[v1,net-next,1/4] net: Convert netdev_chain to blocking_notifier.

Message ID 20250104063735.36945-2-kuniyu@amazon.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series net: Hold per-netns RTNL during netdev notifier registration. | 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: 1 this patch: 1
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 3 this patch: 3
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: 6 this patch: 6
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 40 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 79 this patch: 79
netdev/source_inline success Was 0 now: 0
netdev/contest fail net-next-2025-01-04--15-00 (tests: 883)

Commit Message

Kuniyuki Iwashima Jan. 4, 2025, 6:37 a.m. UTC 
Once RTNL is converted to per-netns, nothing protects
netdev_chain.

A netdev notifier might disappear while being used by
raw_notifier_call_chain().

Let's convert netdev_chain to blocking_notifier to add
its dedicated rwsem.

Given netdev_chain is touched under RTNL by only one user
at the same time, adding rwsem is unlikely to cause regression.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 net/core/dev.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/net/core/dev.c b/net/core/dev.c
index e7223972b9aa..404f5bda821b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -444,7 +444,7 @@  static void unlist_netdevice(struct net_device *dev)
  *	Our notifier list
  */
 
-static RAW_NOTIFIER_HEAD(netdev_chain);
+static BLOCKING_NOTIFIER_HEAD(netdev_chain);
 
 /*
  *	Device drivers call our routines to queue packets here. We empty the
@@ -1770,7 +1770,7 @@  int register_netdevice_notifier(struct notifier_block *nb)
 	/* Close race with setup_net() and cleanup_net() */
 	down_write(&pernet_ops_rwsem);
 	rtnl_lock();
-	err = raw_notifier_chain_register(&netdev_chain, nb);
+	err = blocking_notifier_chain_register(&netdev_chain, nb);
 	if (err)
 		goto unlock;
 	if (dev_boot_phase)
@@ -1790,7 +1790,7 @@  int register_netdevice_notifier(struct notifier_block *nb)
 	for_each_net_continue_reverse(net)
 		call_netdevice_unregister_net_notifiers(nb, net);
 
-	raw_notifier_chain_unregister(&netdev_chain, nb);
+	blocking_notifier_chain_unregister(&netdev_chain, nb);
 	goto unlock;
 }
 EXPORT_SYMBOL(register_netdevice_notifier);
@@ -1817,7 +1817,7 @@  int unregister_netdevice_notifier(struct notifier_block *nb)
 	/* Close race with setup_net() and cleanup_net() */
 	down_write(&pernet_ops_rwsem);
 	rtnl_lock();
-	err = raw_notifier_chain_unregister(&netdev_chain, nb);
+	err = blocking_notifier_chain_unregister(&netdev_chain, nb);
 	if (err)
 		goto unlock;
 
@@ -1993,7 +1993,7 @@  int call_netdevice_notifiers_info(unsigned long val,
 	ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
 	if (ret & NOTIFY_STOP_MASK)
 		return ret;
-	return raw_notifier_call_chain(&netdev_chain, val, info);
+	return blocking_notifier_call_chain(&netdev_chain, val, info);
 }
 
 /**