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authorChristian Brauner <christian.brauner@ubuntu.com>2020-08-19 14:06:36 +0200
committerChristian Brauner <christian.brauner@ubuntu.com>2020-08-19 14:06:36 +0200
commit8b8f3e666fc6c2f33acb7ec6c0c66946307baddb (patch)
tree368fe35a068608cce6908f3c3926184a88a126cd /net/ipv4/tcp_metrics.c
parentns: Add a common refcount into ns_common (diff)
downloadlinux-8b8f3e666fc6c2f33acb7ec6c0c66946307baddb.tar.xz
linux-8b8f3e666fc6c2f33acb7ec6c0c66946307baddb.zip
net: Use generic ns_common::count
Switch over network namespaces to use the newly introduced common lifetime counter. Network namespaces have an additional counter named "passive". This counter does not guarantee that the network namespace is not already de-initialized and so isn't concerned with the actual lifetime of the network namespace; only the "count" counter is. So the latter is moved into struct ns_common. Currently every namespace type has its own lifetime counter which is stored in the specific namespace struct. The lifetime counters are used identically for all namespaces types. Namespaces may of course have additional unrelated counters and these are not altered. This introduces a common lifetime counter into struct ns_common. The ns_common struct encompasses information that all namespaces share. That should include the lifetime counter since its common for all of them. It also allows us to unify the type of the counters across all namespaces. Most of them use refcount_t but one uses atomic_t and at least one uses kref. Especially the last one doesn't make much sense since it's just a wrapper around refcount_t since 2016 and actually complicates cleanup operations by having to use container_of() to cast the correct namespace struct out of struct ns_common. Having the lifetime counter for the namespaces in one place reduces maintenance cost. Not just because after switching all namespaces over we will have removed more code than we added but also because the logic is more easily understandable and we indicate to the user that the basic lifetime requirements for all namespaces are currently identical. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> [christian.brauner@ubuntu.com: rewrite commit] Link: https://lore.kernel.org/r/159644977635.604812.1319877322927063560.stgit@localhost.localdomain Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Diffstat (limited to 'net/ipv4/tcp_metrics.c')
-rw-r--r--net/ipv4/tcp_metrics.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 279db8822439..39710c417565 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -887,7 +887,7 @@ static void tcp_metrics_flush_all(struct net *net)
pp = &hb->chain;
for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) {
match = net ? net_eq(tm_net(tm), net) :
- !refcount_read(&tm_net(tm)->count);
+ !refcount_read(&tm_net(tm)->ns.count);
if (match) {
*pp = tm->tcpm_next;
kfree_rcu(tm, rcu_head);