WSL2-Linux-Kernel/include
Christian Brauner 8b8f3e666f
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>
2020-08-19 14:06:36 +02:00
..
acpi
asm-generic iomap: constify ioreadX() iomem argument (as in generic implementation) 2020-08-14 19:56:57 -07:00
clocksource include/: replace HTTP links with HTTPS ones 2020-08-12 10:57:59 -07:00
crypto
drm Linux 5.8 2020-08-11 11:58:31 +10:00
dt-bindings Here's some more updates that missed the last pull request because I 2020-08-12 12:19:49 -07:00
keys
kunit
kvm
linux ns: Add a common refcount into ns_common 2020-08-19 13:47:15 +02:00
math-emu
media
memory
misc
net net: Use generic ns_common::count 2020-08-19 14:06:36 +02:00
pcmcia
ras
rdma
scsi
soc include/: replace HTTP links with HTTPS ones 2020-08-12 10:57:59 -07:00
sound
target
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-08-13 20:03:11 -07:00
uapi ptrace: Prevent kernel-infoleak in ptrace_get_syscall_info() 2020-08-18 13:39:23 +02:00
vdso
video
xen xen: branch for v5.9-rc1b 2020-08-14 13:34:37 -07:00