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| author | Kirill Tkhai <ktkhai@virtuozzo.com> | 2020-08-03 13:16:50 +0300 |
|---|---|---|
| committer | Christian Brauner <christian.brauner@ubuntu.com> | 2020-08-19 14:14:29 +0200 |
| commit | f387882d8d3eda7c7b13e330c73907035569ce4a (patch) | |
| tree | d955b22fd2e25b4f62101191a0ab3fd6df70896f /kernel/cgroup | |
| parent | 1a7b8969e664d6af328f00fe6eb7aabd61a71d13 (diff) | |
| download | linux-f387882d8d3eda7c7b13e330c73907035569ce4a.tar.gz | |
cgroup: Use generic ns_common::count
Switch over cgroup namespaces to use the newly introduced common lifetime counter. 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> Link: https://lore.kernel.org/r/159644980994.604812.383801057081594972.stgit@localhost.localdomain Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Diffstat (limited to 'kernel/cgroup')
| -rw-r--r-- | kernel/cgroup/cgroup.c | 2 | ||||
| -rw-r--r-- | kernel/cgroup/namespace.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index dd247747ec14..22e466926853 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -199,7 +199,7 @@ static u16 have_canfork_callback __read_mostly; /* cgroup namespace for init task */ struct cgroup_namespace init_cgroup_ns = { - .count = REFCOUNT_INIT(2), + .ns.count = REFCOUNT_INIT(2), .user_ns = &init_user_ns, .ns.ops = &cgroupns_operations, .ns.inum = PROC_CGROUP_INIT_INO, diff --git a/kernel/cgroup/namespace.c b/kernel/cgroup/namespace.c index 812a61afd538..f5e8828c109c 100644 --- a/kernel/cgroup/namespace.c +++ b/kernel/cgroup/namespace.c @@ -32,7 +32,7 @@ static struct cgroup_namespace *alloc_cgroup_ns(void) kfree(new_ns); return ERR_PTR(ret); } - refcount_set(&new_ns->count, 1); + refcount_set(&new_ns->ns.count, 1); new_ns->ns.ops = &cgroupns_operations; return new_ns; } |