dlan17/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mnt: expose pointer to init_mnt_ns

Browse Source 
There's various scenarios where we need to know whether we are in the
initial set of namespaces or not to e.g., shortcut permission checking.
All namespaces expose that information. Let's do that too.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner
2025-09-19 14:26:18 +02:00
parent 93f67a7dda
commit b2a0b19208
2 changed files with 18 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files
fs/namespace.c
+16 -11
View File
@@ -6008,27 +6008,32 @@ SYSCALL_DEFINE4(listmount, const struct mnt_id_req __user *, req,
return ret;
}
struct mnt_namespace init_mnt_ns = {
.ns.inum = PROC_MNT_INIT_INO,
.ns.ops = &mntns_operations,
.user_ns = &init_user_ns,
.ns.count = REFCOUNT_INIT(1),
.passive = REFCOUNT_INIT(1),
.mounts = RB_ROOT,
.poll = __WAIT_QUEUE_HEAD_INITIALIZER(init_mnt_ns.poll),
};
static void __init init_mount_tree(void)
{
struct vfsmount *mnt;
struct mount *m;
struct mnt_namespace *ns;
struct path root;
mnt = vfs_kern_mount(&rootfs_fs_type, 0, "rootfs", NULL);
if (IS_ERR(mnt))
panic("Can't create rootfs");
ns = alloc_mnt_ns(&init_user_ns, true);
if (IS_ERR(ns))
panic("Can't allocate initial namespace");
ns->ns.inum = PROC_MNT_INIT_INO;
m = real_mount(mnt);
ns->root = m;
ns->nr_mounts = 1;
mnt_add_to_ns(ns, m);
init_task.nsproxy->mnt_ns = ns;
get_mnt_ns(ns);
init_mnt_ns.root = m;
init_mnt_ns.nr_mounts = 1;
mnt_add_to_ns(&init_mnt_ns, m);
init_task.nsproxy->mnt_ns = &init_mnt_ns;
get_mnt_ns(&init_mnt_ns);
root.mnt = mnt;
root.dentry = mnt->mnt_root;
@@ -6036,7 +6041,7 @@ static void __init init_mount_tree(void)
set_fs_pwd(current->fs, &root);
set_fs_root(current->fs, &root);
ns_tree_add(ns);
ns_tree_add(&init_mnt_ns);
}
void __init mnt_init(void)
include/linux/mnt_namespace.h
+2
View File
@@ -11,6 +11,8 @@ struct fs_struct;
struct user_namespace;
struct ns_common;
extern struct mnt_namespace init_mnt_ns;
extern struct mnt_namespace *copy_mnt_ns(unsigned long, struct mnt_namespace *,
struct user_namespace *, struct fs_struct *);
extern void put_mnt_ns(struct mnt_namespace *ns);