diff mbox series

[net-next,08/13] rtnetlink: add RTNL_FLAG_DUMP_UNLOCKED flag

Message ID 20240221105915.829140-9-edumazet@google.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series rtnetlink: reduce RTNL pressure for dumps | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
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: 5757 this patch: 5757
netdev/build_tools success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 3 maintainers not CCed: jiri@resnulli.us shayagr@amazon.com idosch@nvidia.com
netdev/build_clang success Errors and warnings before: 2062 this patch: 2062
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: 6061 this patch: 6061
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 50 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 7 this patch: 7
netdev/source_inline success Was 0 now: 0
netdev/contest warning net-next-2024-02-21--15-00 (tests: 897)

Commit Message

Eric Dumazet Feb. 21, 2024, 10:59 a.m. UTC 
Similarly to RTNL_FLAG_DOIT_UNLOCKED, this new flag
allows dump operations registered via rtnl_register()
or rtnl_register_module() to opt-out from RTNL protection.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/linux/netlink.h  | 2 ++
 include/net/rtnetlink.h  | 1 +
 net/core/rtnetlink.c     | 2 ++
 net/netlink/af_netlink.c | 3 +++
 4 files changed, 8 insertions(+)
diff mbox series

Patch

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 1a4445bf2ab9acff630b3712453c8a6cdf8fc47c..5df7340d4dabc0c0b1728dafde43b5522dacd024 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -291,6 +291,7 @@  struct netlink_callback {
 	u16			answer_flags;
 	u32			min_dump_alloc;
 	unsigned int		prev_seq, seq;
+	int			flags;
 	bool			strict_check;
 	union {
 		u8		ctx[48];
@@ -323,6 +324,7 @@  struct netlink_dump_control {
 	void *data;
 	struct module *module;
 	u32 min_dump_alloc;
+	int flags;
 };
 
 int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 6506221c5fe31f49ccaca470e0b24dffb703c28e..3bfb80bad1739d244a3906fa7f0e1a606dfaf868 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -12,6 +12,7 @@  typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *);
 enum rtnl_link_flags {
 	RTNL_FLAG_DOIT_UNLOCKED		= BIT(0),
 	RTNL_FLAG_BULK_DEL_SUPPORTED	= BIT(1),
+	RTNL_FLAG_DUMP_UNLOCKED		= BIT(2),
 };
 
 enum rtnl_kinds {
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 060543fe7919c13c7a5c6cf22f9e7606d0897345..1b26dfa5668d22fb2e30ceefbf143e98df13ae29 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -6532,6 +6532,7 @@  static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 		}
 		owner = link->owner;
 		dumpit = link->dumpit;
+		flags = link->flags;
 
 		if (type == RTM_GETLINK - RTM_BASE)
 			min_dump_alloc = rtnl_calcit(skb, nlh);
@@ -6549,6 +6550,7 @@  static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 				.dump		= dumpit,
 				.min_dump_alloc	= min_dump_alloc,
 				.module		= owner,
+				.flags		= flags,
 			};
 			err = netlink_dump_start(rtnl, skb, nlh, &c);
 			/* netlink_dump_start() will keep a reference on
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 84cad7be6d4335bfb5301ef49f84af8e7b3bc842..be5792b638aa563232cdb96de8c97c4fe45b3718 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2261,6 +2261,8 @@  static int netlink_dump(struct sock *sk, bool lock_taken)
 
 		cb->extack = &extack;
 
+		if (cb->flags & RTNL_FLAG_DUMP_UNLOCKED)
+			extra_mutex = NULL;
 		if (extra_mutex)
 			mutex_lock(extra_mutex);
 		nlk->dump_done_errno = cb->dump(skb, cb);
@@ -2355,6 +2357,7 @@  int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 	cb->data = control->data;
 	cb->module = control->module;
 	cb->min_dump_alloc = control->min_dump_alloc;
+	cb->flags = control->flags;
 	cb->skb = skb;
 
 	cb->strict_check = nlk_test_bit(STRICT_CHK, NETLINK_CB(skb).sk);