diff mbox series

[net-next,5/6] inet: prepare inet_base_seq() to run without RTNL

Message ID 20240229114016.2995906-6-edumazet@google.com (mailing list archive)
State Accepted
Commit 590e92cdc835fcf435d8611f2477fff0e16877c7
Delegated to: Netdev Maintainers
Headers show
Series inet: no longer use RTNL to protect inet_dump_ifaddr() | 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: 947 this patch: 947
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: 958 this patch: 958
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: 964 this patch: 964
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 19 lines checked
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-2024-03-01--06-00 (tests: 882)

Commit Message

Eric Dumazet Feb. 29, 2024, 11:40 a.m. UTC 
In the following patch, inet_base_seq() will no longer be called
with RTNL held.

Add READ_ONCE()/WRITE_ONCE() annotations in dev_base_seq_inc()
and inet_base_seq().

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/core/dev.c     | 5 +++--
 net/ipv4/devinet.c | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/net/core/dev.c b/net/core/dev.c
index 053fac78305c7322b894ceb07a925f7e64ed70aa..873e095e141db3e631e51763435ddafbf0d280af 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -180,8 +180,9 @@  static DECLARE_RWSEM(devnet_rename_sem);
 
 static inline void dev_base_seq_inc(struct net *net)
 {
-	while (++net->dev_base_seq == 0)
-		;
+	unsigned int val = net->dev_base_seq + 1;
+
+	WRITE_ONCE(net->dev_base_seq, val ?: 1);
 }
 
 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 550b775cbbf3c140c66e224c69996df7051b3d36..2afe78dfc3c2f6c0394925f1c35532a2dfd26d71 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1837,7 +1837,7 @@  static int in_dev_dump_addr(struct in_device *in_dev, struct sk_buff *skb,
 static u32 inet_base_seq(const struct net *net)
 {
 	u32 res = atomic_read(&net->ipv4.dev_addr_genid) +
-		  net->dev_base_seq;
+		  READ_ONCE(net->dev_base_seq);
 
 	/* Must not return 0 (see nl_dump_check_consistent()).
 	 * Chose a value far away from 0.