From f044c8847bb61eff5e1e95b6f6bb950e7f4a73a4 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 2 Nov 2017 15:27:45 +0000 Subject: afs: Lay the groundwork for supporting network namespaces Lay the groundwork for supporting network namespaces (netns) to the AFS filesystem by moving various global features to a network-namespace struct (afs_net) and providing an instance of this as a temporary global variable that everything uses via accessor functions for the moment. The following changes have been made: (1) Store the netns in the superblock info. This will be obtained from the mounter's nsproxy on a manual mount and inherited from the parent superblock on an automount. (2) The cell list is made per-netns. It can be viewed through /proc/net/afs/cells and also be modified by writing commands to that file. (3) The local workstation cell is set per-ns in /proc/net/afs/rootcell. This is unset by default. (4) The 'rootcell' module parameter, which sets a cell and VL server list modifies the init net namespace, thereby allowing an AFS root fs to be theoretically used. (5) The volume location lists and the file lock manager are made per-netns. (6) The AF_RXRPC socket and associated I/O bits are made per-ns. The various workqueues remain global for the moment. Changes still to be made: (1) /proc/fs/afs/ should be moved to /proc/net/afs/ and a symlink emplaced from the old name. (2) A per-netns subsys needs to be registered for AFS into which it can store its per-netns data. (3) Rather than the AF_RXRPC socket being opened on module init, it needs to be opened on the creation of a superblock in that netns. (4) The socket needs to be closed when the last superblock using it is destroyed and all outstanding client calls on it have been completed. This prevents a reference loop on the namespace. (5) It is possible that several namespaces will want to use AFS, in which case each one will need its own UDP port. These can either be set through /proc/net/afs/cm_port or the kernel can pick one at random. The init_ns gets 7001 by default. Other issues that need resolving: (1) The DNS keyring needs net-namespacing. (2) Where do upcalls go (eg. DNS request-key upcall)? (3) Need something like open_socket_in_file_ns() syscall so that AFS command line tools attempting to operate on an AFS file/volume have their RPC calls go to the right place. Signed-off-by: David Howells --- include/uapi/linux/magic.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/magic.h b/include/uapi/linux/magic.h index aa50113ebe5b..1a6fee974116 100644 --- a/include/uapi/linux/magic.h +++ b/include/uapi/linux/magic.h @@ -47,6 +47,7 @@ #define OPENPROM_SUPER_MAGIC 0x9fa1 #define QNX4_SUPER_MAGIC 0x002f /* qnx4 fs detection */ #define QNX6_SUPER_MAGIC 0x68191122 /* qnx6 fs detection */ +#define AFS_FS_MAGIC 0x6B414653 #define REISERFS_SUPER_MAGIC 0x52654973 /* used by gcc */ /* used by file system utilities that -- cgit v1.2.3