23 Sep, 2006

40 commits

  • Signed-off-by: Trond Myklebust

    Trond Myklebust
     
  • Signed-off-by: Trond Myklebust

    Trond Myklebust
     
  • Signed-off-by: Trond Myklebust

    Trond Myklebust
     
  • Now that we have a copy of the symlink path in the page cache, we can pass
    a struct page down to the XDR routines instead of a string buffer.

    Test plan:
    Connectathon, all NFS versions.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Currently the NFS client does not cache symlinks it creates. They get
    cached only when the NFS client reads them back from the server.

    Copy the symlink into the page cache before sending it.

    Test plan:
    Connectathon, all NFS versions.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • If the LOOKUP or GETATTR in nfs_instantiate fail, nfs_instantiate will do a
    d_drop before returning. But some callers already do a d_drop in the case
    of an error return. Make certain we do only one d_drop in all error paths.

    This issue was introduced because over time, the symlink proc API diverged
    slightly from the create/mkdir/mknod proc API. To prevent other coding
    mistakes of this type, change the symlink proc API to be more like
    create/mkdir/mknod and move the nfs_instantiate call into the symlink proc
    routines so it is used in exactly the same way for create, mkdir, mknod,
    and symlink.

    Test plan:
    Connectathon, all versions of NFS.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • In the early days of NFS, there was no duplicate reply cache on the server.
    Thus retransmitted non-idempotent requests often found that the request had
    already completed on the server. To avoid passing an unanticipated return
    code to unsuspecting applications, NFS clients would often shunt error
    codes that implied the request had been retried but already completed.

    Thanks to NFS over TCP, duplicate reply caches on the server, and network
    performance and reliability improvements, it is safe to remove such checks.

    Test plan:
    None.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • This patch is optional.

    It has been suggested that the RPC client internal functions used by upper
    layer protocols (such as NFS) be exported via EXPORT_SYMBOL_GPL. This
    patch does that.

    Test plan:
    Compile kernel with CONFIG_NFS enabled as a module.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • The two function call API for creating a new RPC client is now obsolete.
    Remove it.

    Also, remove an unnecessary check to see whether the caller is capable of
    using privileged network services. The kernel RPC client always uses a
    privileged ephemeral port by default; callers are responsible for checking
    the authority of users to make use of any RPC service, or for specifying
    that a nonprivileged port is acceptable.

    Test plan:
    Repeated runs of Connectathon locking suite. Check network trace to ensure
    correctness of NLM requests and replies.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Replace xprt_create_proto/rpc_create_client calls in pmap_clnt.c with new
    rpc_create() API.

    Test plan:
    Repeated runs of Connectathon locking suite. Check network trace for
    proper PMAP calls and replies.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Replace xprt_create_proto/rpc_create_client call in NFS server callback
    functions to use new rpc_create() API.

    Test plan:
    NFSv4 delegation functionality tests.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Convert NFS client mount logic to use rpc_create() instead of the old
    xprt_create_proto/rpc_create_client API.

    Test plan:
    Mount stress tests.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Replace xprt_create_proto/rpc_create_client with new rpc_create()
    interface in the Network Lock Manager.

    Note that the semantics of NLM transports is now "hard" instead of "soft"
    to provide a better guarantee that lock requests will get to the server.

    Test plan:
    Repeated runs of Connectathon locking suite. Check network trace to ensure
    NLM requests are working correctly.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Prepare for more generic transport endpoint handling needed by transports
    that might use different forms of addressing, such as IPv6.

    Introduce a single function call to replace the two-call
    xprt_create_proto/rpc_create_client API. Define a new rpc_create_args
    structure that allows callers to pass in remote endpoint addresses of
    varying length.

    Test-plan:
    Compile kernel with CONFIG_NFS enabled.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Remove some unused macros related to accessing an RPC peer address

    Test plan:
    Compile kernel with CONFIG_NFS option enabled.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • IPv6 addresses are big (128 bytes). Now that no RPC client consumers treat
    the addr field in rpc_xprt structs as an opaque, and access it only via the
    API calls, we can safely widen the field in the rpc_xprt struct to
    accomodate larger addresses.

    Test plan:
    Compile kernel with CONFIG_NFS enabled.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Hide the details of how the RPC client stores remote peer addresses from
    the RPC pipefs implementation.

    Test plan:
    Connectathon with Kerberos 5 authentication.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Provide an API for formatting the remote peer address for printing without
    exposing its internal structure. The address could be dynamic, so we
    support a function call to get the address rather than reading it straight
    out of a structure.

    Test-plan:
    Destructive testing (unplugging the network temporarily). Probably need
    to rig a server where certain services aren't running, or that returns an
    error for some typical operation.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Add a new method to the transport switch API to provide a way to convert
    the opaque contents of xprt->addr to a human-readable string.

    Test plan:
    Compile kernel with CONFIG_NFS enabled.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • include/linux/sunrpc/clnt.h already includes include/linux/sunrpc/xprt.h.
    We can remove xprt.h from source files that already include clnt.h.
    Likewise include/linux/sunrpc/timer.h.

    Test plan:
    Compile kernel with CONFIG_NFS enabled.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Hide the details of how the RPC client stores remote peer addresses from
    the RPC portmapper.

    Test plan:
    Destructive testing (unplugging the network temporarily). Connectathon
    with UDP and TCP. NFSv2/3 and NFSv4 mounting should be carefully checked.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Hide the details of how the RPC client stores remote peer addresses from
    the Network Lock Manager.

    Test plan:
    Destructive testing (unplugging the network temporarily). Connectathon
    with UDP and TCP.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Provide an API for retrieving the remote peer address without allowing
    direct access to the rpc_xprt struct.

    Test-plan:
    Compile kernel with CONFIG_NFS enabled.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Introduce a clean transport switch API for plugging in different types of
    rpcbind mechanisms. For instance, rpcbind can cleanly replace the
    existing portmapper client, or a transport can choose to implement RPC
    binding any way it likes.

    Test plan:
    Destructive testing (unplugging the network temporarily). Connectathon
    with UDP and TCP. NFSv2/3 and NFSv4 mounting should be carefully checked.
    Probably need to rig a server where certain services aren't running, or
    that returns an error for some typical operation.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • The previous patches removed the last user of RPC child tasks, so we can
    remove support for child tasks from net/sunrpc/sched.c now.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Add comments for external functions, use modern function definition style,
    and fix up dprintk formatting.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Move connection and bind state that was maintained in the rpc_clnt
    structure to the rpc_xprt structure. This will allow the creation of
    a clean API for plugging in different types of bind mechanisms.

    This brings improvements such as the elimination of a single spin lock to
    control serialization for all in-kernel RPC binding. A set of per-xprt
    bitops is used to serialize tasks during RPC binding, just like it now
    works for making RPC transport connections.

    Test-plan:
    Destructive testing (unplugging the network temporarily). Connectathon
    with UDP and TCP. NFSv2/3 and NFSv4 mounting should be carefully checked.
    Probably need to rig a server where certain services aren't running, or
    that returns an error for some typical operation.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • Hide the contents and format of xprt->addr by eliminating direct uses
    of the xprt->addr.sin_port field. This change is required to support
    alternate RPC host address formats (eg IPv6).

    Test-plan:
    Destructive testing (unplugging the network temporarily). Repeated runs of
    Connectathon locking suite with UDP and TCP.

    Signed-off-by: Chuck Lever
    Signed-off-by: Trond Myklebust

    Chuck Lever
     
  • The scheme to indicate which services have been started up appears to be
    seriously broken.

    Signed-off-by: Trond Myklebust

    Trond Myklebust
     
  • Signed-off-by: Trond Myklebust

    Trond Myklebust
     
  • Invoke security_d_instantiate() on root dentries after allocating them with
    dentry_alloc_anon(). Normally dentry_alloc_root() would do that, but we don't
    call that as we don't want to assign a name to the root dentry at this point
    (we may discover the real name later).

    Signed-Off-By: David Howells
    Signed-off-by: Trond Myklebust

    David Howells
     
  • Fix an error handling problem: nfs_put_client() can be given a NULL pointer if
    nfs_free_server() is asked to destroy a partially initialised record.

    Signed-Off-By: David Howells
    Signed-off-by: Trond Myklebust

    David Howells
     
  • Make two new proc files available:

    /proc/fs/nfsfs/servers
    /proc/fs/nfsfs/volumes

    The first lists the servers with which we are currently dealing (struct
    nfs_client), and the second lists the volumes we have on those servers (struct
    nfs_server).

    Signed-Off-By: David Howells
    Signed-off-by: Trond Myklebust

    David Howells
     
  • The attached patch makes NFS share superblocks between mounts from the same
    server and FSID over the same protocol.

    It does this by creating each superblock with a false root and returning the
    real root dentry in the vfsmount presented by get_sb(). The root dentry set
    starts off as an anonymous dentry if we don't already have the dentry for its
    inode, otherwise it simply returns the dentry we already have.

    We may thus end up with several trees of dentries in the superblock, and if at
    some later point one of anonymous tree roots is discovered by normal filesystem
    activity to be located in another tree within the superblock, the anonymous
    root is named and materialises attached to the second tree at the appropriate
    point.

    Why do it this way? Why not pass an extra argument to the mount() syscall to
    indicate the subpath and then pathwalk from the server root to the desired
    directory? You can't guarantee this will work for two reasons:

    (1) The root and intervening nodes may not be accessible to the client.

    With NFS2 and NFS3, for instance, mountd is called on the server to get
    the filehandle for the tip of a path. mountd won't give us handles for
    anything we don't have permission to access, and so we can't set up NFS
    inodes for such nodes, and so can't easily set up dentries (we'd have to
    have ghost inodes or something).

    With this patch we don't actually create dentries until we get handles
    from the server that we can use to set up their inodes, and we don't
    actually bind them into the tree until we know for sure where they go.

    (2) Inaccessible symbolic links.

    If we're asked to mount two exports from the server, eg:

    mount warthog:/warthog/aaa/xxx /mmm
    mount warthog:/warthog/bbb/yyy /nnn

    We may not be able to access anything nearer the root than xxx and yyy,
    but we may find out later that /mmm/www/yyy, say, is actually the same
    directory as the one mounted on /nnn. What we might then find out, for
    example, is that /warthog/bbb was actually a symbolic link to
    /warthog/aaa/xxx/www, but we can't actually determine that by talking to
    the server until /warthog is made available by NFS.

    This would lead to having constructed an errneous dentry tree which we
    can't easily fix. We can end up with a dentry marked as a directory when
    it should actually be a symlink, or we could end up with an apparently
    hardlinked directory.

    With this patch we need not make assumptions about the type of a dentry
    for which we can't retrieve information, nor need we assume we know its
    place in the grand scheme of things until we actually see that place.

    This patch reduces the possibility of aliasing in the inode and page caches for
    inodes that may be accessed by more than one NFS export. It also reduces the
    number of superblocks required for NFS where there are many NFS exports being
    used from a server (home directory server + autofs for example).

    This in turn makes it simpler to do local caching of network filesystems, as it
    can then be guaranteed that there won't be links from multiple inodes in
    separate superblocks to the same cache file.

    Obviously, cache aliasing between different levels of NFS protocol could still
    be a problem, but at least that gives us another key to use when indexing the
    cache.

    This patch makes the following changes:

    (1) The server record construction/destruction has been abstracted out into
    its own set of functions to make things easier to get right. These have
    been moved into fs/nfs/client.c.

    All the code in fs/nfs/client.c has to do with the management of
    connections to servers, and doesn't touch superblocks in any way; the
    remaining code in fs/nfs/super.c has to do with VFS superblock management.

    (2) The sequence of events undertaken by NFS mount is now reordered:

    (a) A volume representation (struct nfs_server) is allocated.

    (b) A server representation (struct nfs_client) is acquired. This may be
    allocated or shared, and is keyed on server address, port and NFS
    version.

    (c) If allocated, the client representation is initialised. The state
    member variable of nfs_client is used to prevent a race during
    initialisation from two mounts.

    (d) For NFS4 a simple pathwalk is performed, walking from FH to FH to find
    the root filehandle for the mount (fs/nfs/getroot.c). For NFS2/3 we
    are given the root FH in advance.

    (e) The volume FSID is probed for on the root FH.

    (f) The volume representation is initialised from the FSINFO record
    retrieved on the root FH.

    (g) sget() is called to acquire a superblock. This may be allocated or
    shared, keyed on client pointer and FSID.

    (h) If allocated, the superblock is initialised.

    (i) If the superblock is shared, then the new nfs_server record is
    discarded.

    (j) The root dentry for this mount is looked up from the root FH.

    (k) The root dentry for this mount is assigned to the vfsmount.

    (3) nfs_readdir_lookup() creates dentries for each of the entries readdir()
    returns; this function now attaches disconnected trees from alternate
    roots that happen to be discovered attached to a directory being read (in
    the same way nfs_lookup() is made to do for lookup ops).

    The new d_materialise_unique() function is now used to do this, thus
    permitting the whole thing to be done under one set of locks, and thus
    avoiding any race between mount and lookup operations on the same
    directory.

    (4) The client management code uses a new debug facility: NFSDBG_CLIENT which
    is set by echoing 1024 to /proc/net/sunrpc/nfs_debug.

    (5) Clone mounts are now called xdev mounts.

    (6) Use the dentry passed to the statfs() op as the handle for retrieving fs
    statistics rather than the root dentry of the superblock (which is now a
    dummy).

    Signed-Off-By: David Howells
    Signed-off-by: Trond Myklebust

    David Howells
     
  • Start rpciod in the server common (nfs_client struct) management code rather
    than in the superblock management code. This means we only need to "start" it
    once per server instead of once per superblock.

    Signed-Off-By: David Howells
    Signed-off-by: Trond Myklebust

    David Howells
     
  • Eliminate nfs_server::client_sys in favour of nfs_client::cl_rpcclient as we
    only really need one per server that we're talking to since it doesn't have any
    security on it.

    The retransmission management variables are also moved to the common struct as
    they're required to set up the cl_rpcclient connection.

    The NFS2/3 client and client_acl connections are thenceforth derived by cloning
    the cl_rpcclient connection and post-applying the authorisation flavour.

    The code for setting up the initial common connection has been moved to
    client.c as nfs_create_rpc_client(). All the NFS program definition tables are
    also moved there as that's where they're now required rather than super.c.

    Signed-Off-By: David Howells
    Signed-off-by: Trond Myklebust

    David Howells
     
  • Move the rpc_ops from the nfs_server struct to the nfs_client struct as they're
    common to all server records of a particular NFS protocol version.

    Signed-Off-By: David Howells
    Signed-off-by: Trond Myklebust

    David Howells
     
  • Make better use of inode* dereferencing macros to hide dereferencing chains
    (including NFS_PROTO and NFS_CLIENT).

    Signed-Off-By: David Howells
    Signed-off-by: Trond Myklebust

    David Howells
     
  • Maintain a common server record for NFS2/3 as well as for NFS4 so that common
    stuff can be moved there from struct nfs_server.

    Signed-Off-By: David Howells
    Signed-off-by: Trond Myklebust

    David Howells
     
  • Add some extra const qualifiers into NFS.

    Signed-Off-By: David Howells
    Signed-off-by: Trond Myklebust

    David Howells