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authorEric W. Biederman <ebiederm@xmission.com>2010-03-07 16:41:34 -0800
committerEric W. Biederman <ebiederm@xmission.com>2011-05-10 14:31:44 -0700
commit6b4e306aa3dc94a0545eb9279475b1ab6209a31f (patch)
treeca8c6dec0805076f0b5ba7c547e3cb2004e3aea2 /fs/proc/inode.c
parent0ee5623f9a6e52df90a78bd21179f8ab370e102e (diff)
downloadlinux-6b4e306aa3dc94a0545eb9279475b1ab6209a31f.tar.bz2
ns: proc files for namespace naming policy.
Create files under /proc/<pid>/ns/ to allow controlling the namespaces of a process. This addresses three specific problems that can make namespaces hard to work with. - Namespaces require a dedicated process to pin them in memory. - It is not possible to use a namespace unless you are the child of the original creator. - Namespaces don't have names that userspace can use to talk about them. The namespace files under /proc/<pid>/ns/ can be opened and the file descriptor can be used to talk about a specific namespace, and to keep the specified namespace alive. A namespace can be kept alive by either holding the file descriptor open or bind mounting the file someplace else. aka: mount --bind /proc/self/ns/net /some/filesystem/path mount --bind /proc/self/fd/<N> /some/filesystem/path This allows namespaces to be named with userspace policy. It requires additional support to make use of these filedescriptors and that will be comming in the following patches. Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'fs/proc/inode.c')
-rw-r--r--fs/proc/inode.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index d15aa1b1cc8f..74b48cfa1bb2 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -28,6 +28,7 @@ static void proc_evict_inode(struct inode *inode)
{
struct proc_dir_entry *de;
struct ctl_table_header *head;
+ const struct proc_ns_operations *ns_ops;
truncate_inode_pages(&inode->i_data, 0);
end_writeback(inode);
@@ -44,6 +45,10 @@ static void proc_evict_inode(struct inode *inode)
rcu_assign_pointer(PROC_I(inode)->sysctl, NULL);
sysctl_head_put(head);
}
+ /* Release any associated namespace */
+ ns_ops = PROC_I(inode)->ns_ops;
+ if (ns_ops && ns_ops->put)
+ ns_ops->put(PROC_I(inode)->ns);
}
static struct kmem_cache * proc_inode_cachep;
@@ -62,6 +67,8 @@ static struct inode *proc_alloc_inode(struct super_block *sb)
ei->pde = NULL;
ei->sysctl = NULL;
ei->sysctl_entry = NULL;
+ ei->ns = NULL;
+ ei->ns_ops = NULL;
inode = &ei->vfs_inode;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
return inode;