For speed and convenience of look-up, the nsfs device ID is looked up for the first instance of a type of namespace, then copied to others of the same type as they are spawned.
Signed-off-by: Richard Guy Briggs <[email protected]> --- fs/namespace.c | 2 ++ fs/nsfs.c | 21 +++++++++++++++++++++ include/linux/ns_common.h | 1 + include/linux/proc_ns.h | 1 + ipc/namespace.c | 1 + kernel/pid_namespace.c | 1 + kernel/user_namespace.c | 1 + kernel/utsname.c | 1 + net/core/net_namespace.c | 2 ++ 9 files changed, 31 insertions(+), 0 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 82ef140..c680675 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2698,6 +2698,7 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns, old = ns->root; new_ns = alloc_mnt_ns(user_ns); + new_ns->ns.dev = ns->ns.dev; if (IS_ERR(new_ns)) return new_ns; @@ -2762,6 +2763,7 @@ static struct mnt_namespace *create_mnt_ns(struct vfsmount *m) struct mount *mnt = real_mount(m); mnt->mnt_ns = new_ns; new_ns->root = mnt; + new_ns->ns.dev = nsfs_dev(); list_add(&mnt->mnt_list, &new_ns->list); } else { mntput(m); diff --git a/fs/nsfs.c b/fs/nsfs.c index 1fcd529..cc785d3 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -4,6 +4,10 @@ #include <linux/proc_ns.h> #include <linux/magic.h> #include <linux/ktime.h> +#include <linux/init_task.h> +#include <linux/utsname.h> +#include <linux/pid_namespace.h> +#include <linux/ipc_namespace.h> static struct vfsmount *nsfs_mnt; @@ -158,6 +162,23 @@ void __init nsfs_init(void) if (IS_ERR(nsfs_mnt)) panic("can't set nsfs up\n"); nsfs_mnt->mnt_sb->s_flags &= ~MS_NOUSER; + init_ipc_ns.ns.dev = init_uts_ns.ns.dev = init_pid_ns.ns.dev + = init_user_ns.ns.dev = nsfs_dev(); +} + +dev_t nsfs_dev(void) +{ + dev_t dev; + + void nssb_to_dev(struct super_block *sb, void *arg){ + dev_t *dev = arg; + + if (sb->s_magic == NSFS_MAGIC) + *dev = sb->s_dev; + } + + iterate_supers(nssb_to_dev, (void*)&dev); + return dev; } static DEFINE_IDA(ns_inum_ida); diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index 85a5c8c..6701070 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -7,6 +7,7 @@ struct ns_common { atomic_long_t stashed; const struct proc_ns_operations *ops; unsigned int inum; + dev_t dev; }; #endif diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index 721d0e2..904d9e7 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -71,4 +71,5 @@ extern int ns_get_name(char *buf, size_t size, struct task_struct *task, const struct proc_ns_operations *ns_ops); extern void nsfs_init(void); +extern dev_t nsfs_dev(void); #endif /* _LINUX_PROC_NS_H */ diff --git a/ipc/namespace.c b/ipc/namespace.c index 068caf1..b24da44 100644 --- a/ipc/namespace.c +++ b/ipc/namespace.c @@ -31,6 +31,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns, kfree(ns); return ERR_PTR(err); } + ns->ns.dev = old_ns->ns.dev; ns->ns.ops = &ipcns_operations; atomic_set(&ns->count, 1); diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index a65ba13..691b9ac 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -108,6 +108,7 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns err = ns_alloc_inum(&ns->ns); if (err) goto out_free_map; + ns->ns.dev = parent_pid_ns->ns.dev; ns->ns.ops = &pidns_operations; kref_init(&ns->kref); diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 4109f83..ec29cd9 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -92,6 +92,7 @@ int create_user_ns(struct cred *new) kmem_cache_free(user_ns_cachep, ns); return ret; } + ns->ns.dev = parent_ns->ns.dev; ns->ns.ops = &userns_operations; atomic_set(&ns->count, 1); diff --git a/kernel/utsname.c b/kernel/utsname.c index 831ea71..54c45e1 100644 --- a/kernel/utsname.c +++ b/kernel/utsname.c @@ -48,6 +48,7 @@ static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns, return ERR_PTR(err); } + ns->ns.dev = old_ns->ns.dev; ns->ns.ops = &utsns_operations; down_read(&uts_sem); diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 70d3450..a706cdd 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -332,6 +332,7 @@ struct net *copy_net_ns(unsigned long flags, mutex_lock(&net_mutex); rv = setup_net(net, user_ns); if (rv == 0) { + net->ns.dev = old_net->ns.dev; rtnl_lock(); list_add_tail_rcu(&net->list, &net_namespace_list); rtnl_unlock(); @@ -639,6 +640,7 @@ static int __init net_ns_init(void) if (setup_net(&init_net, &init_user_ns)) panic("Could not setup the initial network namespace"); + init_net.ns.dev = nsfs_dev(); rtnl_lock(); list_add_tail_rcu(&init_net.list, &net_namespace_list); rtnl_unlock(); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
