Unverified Commit 5612ff3e authored by Christian Brauner's avatar Christian Brauner
Browse files

nscommon: simplify initialization 



There's a lot of information that namespace implementers don't need to
know about at all. Encapsulate this all in the initialization helper.

Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent d5b27cb8

fs/namespace.c

+3 −2
Original line number Diff line number Diff line
@@ -4104,8 +4104,9 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns, bool a 
	}



	if (anon)

		new_ns->ns.inum = MNT_NS_ANON_INO;

	ret = ns_common_init(&new_ns->ns, &mntns_operations, !anon);

		ret = ns_common_init_inum(new_ns, &mntns_operations, MNT_NS_ANON_INO);

	else

		ret = ns_common_init(new_ns, &mntns_operations);

	if (ret) {

		kfree(new_ns);

		dec_mnt_namespaces(ucounts);

include/linux/ns_common.h

+37 −2
Original line number Diff line number Diff line
@@ -16,6 +16,15 @@ struct time_namespace; 
struct user_namespace;

struct uts_namespace;



extern struct cgroup_namespace init_cgroup_ns;

extern struct ipc_namespace init_ipc_ns;

extern struct mnt_namespace init_mnt_ns;

extern struct net init_net;

extern struct pid_namespace init_pid_ns;

extern struct time_namespace init_time_ns;

extern struct user_namespace init_user_ns;

extern struct uts_namespace init_uts_ns;



struct ns_common {

	struct dentry *stashed;

	const struct proc_ns_operations *ops;
@@ -31,8 +40,7 @@ struct ns_common { 
	};

};



int ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops,

		   bool alloc_inum);

int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, int inum);



#define to_ns_common(__ns)                              \

	_Generic((__ns),                                \
@@ -45,4 +53,31 @@ int ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, 
		struct user_namespace *:   &(__ns)->ns, \

		struct uts_namespace *:    &(__ns)->ns)



#define ns_init_inum(__ns)                                     \

	_Generic((__ns),                                       \

		struct cgroup_namespace *: CGROUP_NS_INIT_INO, \

		struct ipc_namespace *:    IPC_NS_INIT_INO,    \

		struct mnt_namespace *:    MNT_NS_INIT_INO,    \

		struct net *:              NET_NS_INIT_INO,    \

		struct pid_namespace *:    PID_NS_INIT_INO,    \

		struct time_namespace *:   TIME_NS_INIT_INO,   \

		struct user_namespace *:   USER_NS_INIT_INO,   \

		struct uts_namespace *:    UTS_NS_INIT_INO)



#define ns_init_ns(__ns)                                    \

	_Generic((__ns),                                    \

		struct cgroup_namespace *: &init_cgroup_ns, \

		struct ipc_namespace *:    &init_ipc_ns,    \

		struct mnt_namespace *:    &init_mnt_ns,     \

		struct net *:              &init_net,       \

		struct pid_namespace *:    &init_pid_ns,    \

		struct time_namespace *:   &init_time_ns,   \

		struct user_namespace *:   &init_user_ns,   \

		struct uts_namespace *:    &init_uts_ns)



#define ns_common_init(__ns, __ops) \

	__ns_common_init(to_ns_common(__ns), __ops, (((__ns) == ns_init_ns(__ns)) ? ns_init_inum(__ns) : 0))



#define ns_common_init_inum(__ns, __ops, __inum) __ns_common_init(to_ns_common(__ns), __ops, __inum)



#endif

ipc/namespace.c

+1 −1
Original line number Diff line number Diff line
@@ -62,7 +62,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns, 
	if (ns == NULL)

		goto fail_dec;



	err = ns_common_init(&ns->ns, &ipcns_operations, true);

	err = ns_common_init(ns, &ipcns_operations);

	if (err)

		goto fail_free;

kernel/cgroup/namespace.c

+1 −1
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ static struct cgroup_namespace *alloc_cgroup_ns(void) 
	new_ns = kzalloc(sizeof(struct cgroup_namespace), GFP_KERNEL_ACCOUNT);

	if (!new_ns)

		return ERR_PTR(-ENOMEM);

	ret = ns_common_init(&new_ns->ns, &cgroupns_operations, true);

	ret = ns_common_init(new_ns, &cgroupns_operations);

	if (ret)

		return ERR_PTR(ret);

	ns_tree_add(new_ns);

kernel/nscommon.c

+8 −9
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only



#include <linux/ns_common.h>

#include <linux/proc_ns.h>



int ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops,

		   bool alloc_inum)

int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, int inum)

{

	if (alloc_inum && !ns->inum) {

		int ret;

		ret = proc_alloc_inum(&ns->inum);

		if (ret)

			return ret;

	}

	refcount_set(&ns->count, 1);

	ns->stashed = NULL;

	ns->ops = ops;

	ns->ns_id = 0;

	RB_CLEAR_NODE(&ns->ns_tree_node);

	INIT_LIST_HEAD(&ns->ns_list_node);



	if (inum) {

		ns->inum = inum;

		return 0;

	}

	return proc_alloc_inum(&ns->inum);

}