NFS: Only reference user namespace from nfs4idmap struct instead of cred

The nfs4idmapper only needs access to the user namespace, and not the
entire cred struct. This replaces the struct cred* member with
struct user_namespace*. This is mostly hygiene, so we don't have to
hold onto the cred object, which has extraneous references to
things like user_struct. This also makes switching away
from init_user_ns more straightforward in the future.

Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Sargun Dhillon 2020-10-12 14:43:39 -07:00 committed by Anna Schumaker
parent a2d24bcb97
commit 61ca2c4afd

View File

@ -46,6 +46,7 @@
#include <keys/user-type.h>
#include <keys/request_key_auth-type.h>
#include <linux/module.h>
#include <linux/user_namespace.h>
#include "internal.h"
#include "netns.h"
@ -69,13 +70,13 @@ struct idmap {
struct rpc_pipe *idmap_pipe;
struct idmap_legacy_upcalldata *idmap_upcall_data;
struct mutex idmap_mutex;
const struct cred *cred;
struct user_namespace *user_ns;
};
static struct user_namespace *idmap_userns(const struct idmap *idmap)
{
if (idmap && idmap->cred)
return idmap->cred->user_ns;
if (idmap && idmap->user_ns)
return idmap->user_ns;
return &init_user_ns;
}
@ -286,7 +287,7 @@ static struct key *nfs_idmap_request_key(const char *name, size_t namelen,
if (ret < 0)
return ERR_PTR(ret);
if (!idmap->cred || idmap->cred->user_ns == &init_user_ns)
if (!idmap->user_ns || idmap->user_ns == &init_user_ns)
rkey = request_key(&key_type_id_resolver, desc, "");
if (IS_ERR(rkey)) {
mutex_lock(&idmap->idmap_mutex);
@ -462,7 +463,7 @@ nfs_idmap_new(struct nfs_client *clp)
return -ENOMEM;
mutex_init(&idmap->idmap_mutex);
idmap->cred = get_cred(clp->cl_rpcclient->cl_cred);
idmap->user_ns = get_user_ns(clp->cl_rpcclient->cl_cred->user_ns);
rpc_init_pipe_dir_object(&idmap->idmap_pdo,
&nfs_idmap_pipe_dir_object_ops,
@ -486,7 +487,7 @@ nfs_idmap_new(struct nfs_client *clp)
err_destroy_pipe:
rpc_destroy_pipe_data(idmap->idmap_pipe);
err:
put_cred(idmap->cred);
get_user_ns(idmap->user_ns);
kfree(idmap);
return error;
}
@ -503,7 +504,7 @@ nfs_idmap_delete(struct nfs_client *clp)
&clp->cl_rpcclient->cl_pipedir_objects,
&idmap->idmap_pdo);
rpc_destroy_pipe_data(idmap->idmap_pipe);
put_cred(idmap->cred);
put_user_ns(idmap->user_ns);
kfree(idmap);
}