[RFC PATCH v4 08/12] nfsd - use namespace if not executing in init namespace

Ian Kent
2015-03-17T02:46:06Z

If nfsd is running within a container the client tracking operations
should run within the originating container also.

Signed-off-by: Ian Kent <ikent@redhat.com>
Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Oleg Nesterov <onestero@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jeff Layton <jeff.layton@primarydata.com>
---
fs/nfsd/netns.h | 3 +++
fs/nfsd/nfs4recover.c | 48 +++++++++++++++++++++++++++++++-----------------
fs/nfsd/nfsctl.c | 6 ++++++
3 files changed, 40 insertions(+), 17 deletions(-)

diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index ea6749a..c85c13a 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -112,6 +112,9 @@ struct nfsd_net {
u32 clientid_counter;

struct svc_serv *nfsd_serv;
+
+ /* Namespace token */
+ long umh_token;
};

/* Simple check to find out if a given net was properly initialized */
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 1c307f0..df13b54 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -1184,7 +1184,8 @@ nfsd4_cltrack_grace_start(time_t grace_start)
}

static int
-nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
+nfsd4_umh_cltrack_upcall(char *cmd, char *arg,
+ char *env0, char *env1, long token)
{
char *envp[3];
char *argv[4];
@@ -1209,7 +1210,11 @@ nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
argv[2] = arg;
argv[3] = NULL;

- ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+ if (token > 0)
+ ret = call_usermodehelper_ns(argv[0], argv, envp,
+ UMH_WAIT_PROC, token);
+ else
+ ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
/*
* Disable the upcall mechanism if we're getting an ENOENT or EACCES
* error. The admin can re-enable it on the fly by using sysfs
@@ -1252,14 +1257,8 @@ nfsd4_umh_cltrack_init(struct net *net)
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);

- /* XXX: The usermode helper s not working in container yet. */
- if (net != &init_net) {
- WARN(1, KERN_ERR "NFSD: attempt to initialize umh client "
- "tracking in a container!\n");
- return -EINVAL;
- }
-
- ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
+ ret = nfsd4_umh_cltrack_upcall("init", NULL,
+ grace_start, NULL, nn->umh_token);
kfree(grace_start);
return ret;
}
@@ -1285,6 +1284,7 @@ nfsd4_umh_cltrack_create(struct nfs4_client *clp)
{
char *hexid, *has_session, *grace_start;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+ int ret;

/*
* With v4.0 clients, there's little difference in outcome between a
@@ -1312,7 +1312,10 @@ nfsd4_umh_cltrack_create(struct nfs4_client *clp)
grace_start = nfsd4_cltrack_grace_start(nn->boot_time);

nfsd4_cltrack_upcall_lock(clp);
- if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
+ ret = nfsd4_umh_cltrack_upcall("create",
+ hexid, has_session, grace_start,
+ nn->umh_token);
+ if (!ret)
set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
nfsd4_cltrack_upcall_unlock(clp);

@@ -1324,7 +1327,9 @@ nfsd4_umh_cltrack_create(struct nfs4_client *clp)
static void
nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
{
+ struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
char *hexid;
+ int ret;

if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return;
@@ -1336,9 +1341,13 @@ nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
}

nfsd4_cltrack_upcall_lock(clp);
- if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
- nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
- clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+ if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
+ ret = nfsd4_umh_cltrack_upcall("remove",
+ hexid, NULL, NULL,
+ nn->umh_token);
+ if (ret == 0)
+ clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+ }
nfsd4_cltrack_upcall_unlock(clp);

kfree(hexid);
@@ -1347,8 +1356,9 @@ nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
static int
nfsd4_umh_cltrack_check(struct nfs4_client *clp)
{
- int ret;
+ struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
char *hexid, *has_session, *legacy;
+ int ret;

if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return 0;
@@ -1366,7 +1376,9 @@ nfsd4_umh_cltrack_check(struct nfs4_client *clp)
if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
ret = 0;
} else {
- ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
+ ret = nfsd4_umh_cltrack_upcall("check", hexid,
+ has_session, legacy,
+ nn->umh_token);
if (ret == 0)
set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
}
@@ -1386,7 +1398,9 @@ nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)

sprintf(timestr, "%ld", nn->boot_time);
legacy = nfsd4_cltrack_legacy_topdir();
- nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
+ nfsd4_umh_cltrack_upcall("gracedone",
+ timestr, legacy, NULL,
+ nn->umh_token);
kfree(legacy);
}

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index aa47d75..0509b65 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1224,6 +1224,8 @@ static __net_init int nfsd_init_net(struct net *net)
goto out_idmap_error;
nn->nfsd4_lease = 90; /* default lease time */
nn->nfsd4_grace = 90;
+ if (net != &init_net)
+ nn->umh_token = umh_ns_get_token(nn->umh_token);
return 0;

out_idmap_error:
@@ -1234,6 +1236,10 @@ out_export_error:

static __net_exit void nfsd_exit_net(struct net *net)
{
+ struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+ umh_ns_put_token(nn->umh_token);
+ nn->umh_token = 0;
nfsd_idmap_shutdown(net);
nfsd_export_shutdown(net);
}