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From: Christian Brauner <christian.brauner@ubuntu.com>
To: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: viro@zeniv.linux.org.uk, adobriyan@gmail.com,
	davem@davemloft.net, ebiederm@xmission.com,
	akpm@linux-foundation.org, areber@redhat.com, serge@hallyn.com,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 02/23] uts: Use generic ns_common::count
Date: Thu, 30 Jul 2020 16:30:35 +0200
Message-ID: <20200730143035.c4c2n3g25wm5u7bk@wittgenstein> (raw)
In-Reply-To: <159611037120.535980.13731766189011538488.stgit@localhost.localdomain>

On Thu, Jul 30, 2020 at 02:59:31PM +0300, Kirill Tkhai wrote:
> Convert uts namespace to use generic counter instead of kref.
> 
> Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
> ---

(sidenote: given that kref is implemented on top of refcount_t I wonder
 whether we shouldn't just slowly convert all places where kref is used
 to refcount_t and remove the kref api.)

Looks good!
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>

>  include/linux/utsname.h |    9 ++++-----
>  init/version.c          |    2 +-
>  kernel/utsname.c        |    7 ++-----
>  3 files changed, 7 insertions(+), 11 deletions(-)
> 
> diff --git a/include/linux/utsname.h b/include/linux/utsname.h
> index 44429d9142ca..2b1737c9b244 100644
> --- a/include/linux/utsname.h
> +++ b/include/linux/utsname.h
> @@ -4,7 +4,6 @@
>  
>  
>  #include <linux/sched.h>
> -#include <linux/kref.h>
>  #include <linux/nsproxy.h>
>  #include <linux/ns_common.h>
>  #include <linux/err.h>
> @@ -22,7 +21,6 @@ struct user_namespace;
>  extern struct user_namespace init_user_ns;
>  
>  struct uts_namespace {
> -	struct kref kref;
>  	struct new_utsname name;
>  	struct user_namespace *user_ns;
>  	struct ucounts *ucounts;
> @@ -33,16 +31,17 @@ extern struct uts_namespace init_uts_ns;
>  #ifdef CONFIG_UTS_NS
>  static inline void get_uts_ns(struct uts_namespace *ns)
>  {
> -	kref_get(&ns->kref);
> +	refcount_inc(&ns->ns.count);
>  }
>  
>  extern struct uts_namespace *copy_utsname(unsigned long flags,
>  	struct user_namespace *user_ns, struct uts_namespace *old_ns);
> -extern void free_uts_ns(struct kref *kref);
> +extern void free_uts_ns(struct uts_namespace *ns);
>  
>  static inline void put_uts_ns(struct uts_namespace *ns)
>  {
> -	kref_put(&ns->kref, free_uts_ns);
> +	if (refcount_dec_and_test(&ns->ns.count))
> +		free_uts_ns(ns);
>  }
>  
>  void uts_ns_init(void);
> diff --git a/init/version.c b/init/version.c
> index cba341161b58..80d2b7566b39 100644
> --- a/init/version.c
> +++ b/init/version.c
> @@ -25,7 +25,7 @@ int version_string(LINUX_VERSION_CODE);
>  #endif
>  
>  struct uts_namespace init_uts_ns = {
> -	.kref = KREF_INIT(2),
> +	.ns.count = REFCOUNT_INIT(2),
>  	.name = {
>  		.sysname	= UTS_SYSNAME,
>  		.nodename	= UTS_NODENAME,
> diff --git a/kernel/utsname.c b/kernel/utsname.c
> index e488d0e2ab45..b1ac3ca870f2 100644
> --- a/kernel/utsname.c
> +++ b/kernel/utsname.c
> @@ -33,7 +33,7 @@ static struct uts_namespace *create_uts_ns(void)
>  
>  	uts_ns = kmem_cache_alloc(uts_ns_cache, GFP_KERNEL);
>  	if (uts_ns)
> -		kref_init(&uts_ns->kref);
> +		refcount_set(&uts_ns->ns.count, 1);
>  	return uts_ns;
>  }
>  
> @@ -103,11 +103,8 @@ struct uts_namespace *copy_utsname(unsigned long flags,
>  	return new_ns;
>  }
>  
> -void free_uts_ns(struct kref *kref)
> +void free_uts_ns(struct uts_namespace *ns)
>  {
> -	struct uts_namespace *ns;
> -
> -	ns = container_of(kref, struct uts_namespace, kref);
>  	dec_uts_namespaces(ns->ucounts);
>  	put_user_ns(ns->user_ns);
>  	ns_free_inum(&ns->ns);
> 
> 

  reply index

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-30 11:59 [PATCH 00/23] proc: Introduce /proc/namespaces/ directory to expose namespaces lineary Kirill Tkhai
2020-07-30 11:59 ` [PATCH 01/23] ns: Add common refcount into ns_common add use it as counter for net_ns Kirill Tkhai
2020-07-30 13:35   ` Christian Brauner
2020-07-30 14:07     ` Kirill Tkhai
2020-07-30 15:59       ` Christian Brauner
2020-07-30 14:30   ` Christian Brauner
2020-07-30 14:34     ` Kirill Tkhai
2020-07-30 14:39       ` Christian Brauner
2020-07-30 11:59 ` [PATCH 02/23] uts: Use generic ns_common::count Kirill Tkhai
2020-07-30 14:30   ` Christian Brauner [this message]
2020-07-30 11:59 ` [PATCH 03/23] ipc: " Kirill Tkhai
2020-07-30 14:32   ` Christian Brauner
2020-07-30 11:59 ` [PATCH 04/23] pid: " Kirill Tkhai
2020-07-30 14:37   ` Christian Brauner
2020-07-30 11:59 ` [PATCH 05/23] user: " Kirill Tkhai
2020-07-30 14:46   ` Christian Brauner
2020-07-30 11:59 ` [PATCH 06/23] mnt: " Kirill Tkhai
2020-07-30 14:49   ` Christian Brauner
2020-07-30 11:59 ` [PATCH 07/23] cgroup: " Kirill Tkhai
2020-07-30 14:50   ` Christian Brauner
2020-07-30 12:00 ` [PATCH 08/23] time: " Kirill Tkhai
2020-07-30 14:52   ` Christian Brauner
2020-07-30 12:00 ` [PATCH 09/23] ns: Introduce ns_idr to be able to iterate all allocated namespaces in the system Kirill Tkhai
2020-07-30 12:23   ` Matthew Wilcox
2020-07-30 13:32     ` Kirill Tkhai
2020-07-30 13:56       ` Matthew Wilcox
2020-07-30 14:12         ` Kirill Tkhai
2020-07-30 14:15           ` Matthew Wilcox
2020-07-30 14:20             ` Kirill Tkhai
2020-07-30 12:00 ` [PATCH 10/23] fs: Rename fs/proc/namespaces.c into fs/proc/task_namespaces.c Kirill Tkhai
2020-07-30 12:00 ` [PATCH 11/23] fs: Add /proc/namespaces/ directory Kirill Tkhai
2020-07-30 12:18   ` Alexey Dobriyan
2020-07-30 13:22     ` Kirill Tkhai
2020-07-30 13:26   ` Christian Brauner
2020-07-30 14:30     ` Kirill Tkhai
2020-07-30 20:47   ` kernel test robot
2020-07-30 22:20   ` kernel test robot
2020-08-05  8:17   ` kernel test robot
2020-08-05  8:17   ` [RFC PATCH] fs: namespaces_dentry_operations can be static kernel test robot
2020-07-30 12:00 ` [PATCH 12/23] user: Free user_ns one RCU grace period after final counter put Kirill Tkhai
2020-07-30 12:00 ` [PATCH 13/23] user: Add user namespaces into ns_idr Kirill Tkhai
2020-07-30 12:00 ` [PATCH 14/23] net: Add net " Kirill Tkhai
2020-07-30 12:00 ` [PATCH 15/23] pid: Eextract child_reaper check from pidns_for_children_get() Kirill Tkhai
2020-07-30 12:00 ` [PATCH 16/23] proc_ns_operations: Add can_get method Kirill Tkhai
2020-07-30 12:00 ` [PATCH 17/23] pid: Add pid namespaces into ns_idr Kirill Tkhai
2020-07-30 12:00 ` [PATCH 18/23] uts: Free uts namespace one RCU grace period after final counter put Kirill Tkhai
2020-07-30 12:01 ` [PATCH 19/23] uts: Add uts namespaces into ns_idr Kirill Tkhai
2020-07-30 12:01 ` [PATCH 20/23] ipc: Add ipc " Kirill Tkhai
2020-07-30 12:01 ` [PATCH 21/23] mnt: Add mount " Kirill Tkhai
2020-07-30 12:01 ` [PATCH 22/23] cgroup: Add cgroup " Kirill Tkhai
2020-07-30 12:01 ` [PATCH 23/23] time: Add time " Kirill Tkhai
2020-07-30 13:08 ` [PATCH 00/23] proc: Introduce /proc/namespaces/ directory to expose namespaces lineary Christian Brauner
2020-07-30 13:38   ` Christian Brauner
2020-07-30 14:34 ` Eric W. Biederman
2020-07-30 14:42   ` Christian Brauner
2020-07-30 15:01   ` Kirill Tkhai
2020-07-30 22:13     ` Eric W. Biederman
2020-07-31  8:48       ` Pavel Tikhomirov
2020-08-03 10:03       ` Kirill Tkhai
2020-08-03 10:51         ` Alexey Dobriyan
2020-08-06  8:05         ` Andrei Vagin
2020-08-07  8:47           ` Kirill Tkhai
2020-08-10 17:34             ` Andrei Vagin
2020-08-11 10:23               ` Kirill Tkhai
2020-08-12 17:53                 ` Andrei Vagin
2020-08-13  8:12                   ` Kirill Tkhai
2020-08-14  1:16                     ` Andrei Vagin
2020-08-14 15:11                       ` Kirill Tkhai
2020-08-14 19:21                         ` Andrei Vagin
2020-08-17 14:05                           ` Kirill Tkhai
2020-08-17 15:48                             ` Eric W. Biederman
2020-08-17 17:47                               ` Christian Brauner
2020-08-17 18:53                                 ` Eric W. Biederman
2020-08-04  5:43     ` Andrei Vagin
2020-08-04 12:11       ` Pavel Tikhomirov
2020-08-04 14:47       ` Kirill Tkhai

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