libceph: enable ceph in a non-default network namespace

Grab a reference on a network namespace of the 'rbd map' (in case of
rbd) or 'mount' (in case of ceph) process and use that to open sockets
instead of always using init_net and bailing if network namespace is
anything but init_net.  Be careful to not share struct ceph_client
instances between different namespaces and don't add any code in the
!CONFIG_NET_NS case.

This is based on a patch from Hong Zhiguo <zhiguohong@tencent.com>.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index e15499422fdc..37753278987a 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -8,6 +8,7 @@
 #include <linux/radix-tree.h>
 #include <linux/uio.h>
 #include <linux/workqueue.h>
+#include <net/net_namespace.h>
 
 #include <linux/ceph/types.h>
 #include <linux/ceph/buffer.h>
@@ -56,6 +57,7 @@ struct ceph_messenger {
         struct ceph_entity_addr my_enc_addr;
 
         atomic_t stopping;
+        possible_net_t net;
         bool nocrc;
         bool tcp_nodelay;
 
@@ -267,6 +269,7 @@ extern void ceph_messenger_init(struct ceph_messenger *msgr,
                         u64 required_features,
                         bool nocrc,
                         bool tcp_nodelay);
+extern void ceph_messenger_fini(struct ceph_messenger *msgr);
 
 extern void ceph_con_init(struct ceph_connection *con, void *private,
                         const struct ceph_connection_operations *ops,