23 Jul, 2007

1 commit


20 Jul, 2007

1 commit


18 Jul, 2007

1 commit

  • I can never remember what the function to register to receive VM pressure
    is called. I have to trace down from __alloc_pages() to find it.

    It's called "set_shrinker()", and it needs Your Help.

    1) Don't hide struct shrinker. It contains no magic.
    2) Don't allocate "struct shrinker". It's not helpful.
    3) Call them "register_shrinker" and "unregister_shrinker".
    4) Call the function "shrink" not "shrinker".
    5) Reduce the 17 lines of waffly comments to 13, but document it properly.

    Signed-off-by: Rusty Russell
    Cc: David Chinner
    Cc: Trond Myklebust
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Rusty Russell
     

11 Jul, 2007

14 commits


01 May, 2007

2 commits

  • READDIRPLUS can be a performance hindrance when the client is working with
    large directories. In addition, some servers still have bugs in their
    implementations (e.g. Tru64 returns wrong values for the fsid).

    Add a mount flag to enable users to turn it off at mount time following the
    implementation in Apple's NFS client.

    Signed-off-by: Steve Dickson
    Signed-off-by: Trond Myklebust

    Steve Dickson
     
  • The nfs statfs function returns a success code on error, and fills the
    output buffer with invalid values. The attached patch makes it return a
    correct error code instead.

    Signed-off-by: Amnon Aaronsohn
    Cc: Trond Myklebust
    Signed-off-by: Andrew Morton
    Signed-off-by: Trond Myklebust
    (Modified patch to reinstate the dprintk())

    Amnon Aaronsohn
     

17 Mar, 2007

1 commit

  • The current NFS client congestion logic is severly broken, it marks the
    backing device congested during each nfs_writepages() call but doesn't
    mirror this in nfs_writepage() which makes for deadlocks. Also it
    implements its own waitqueue.

    Replace this by a more regular congestion implementation that puts a cap on
    the number of active writeback pages and uses the bdi congestion waitqueue.

    Also always use an interruptible wait since it makes sense to be able to
    SIGKILL the process even for mounts without 'intr'.

    Signed-off-by: Peter Zijlstra
    Acked-by: Trond Myklebust
    Cc: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Peter Zijlstra
     

13 Feb, 2007

3 commits


04 Feb, 2007

1 commit


21 Oct, 2006

1 commit


04 Oct, 2006

1 commit


25 Sep, 2006

1 commit

  • Some file systems want to manually d_move() the dentries involved in a
    rename. We can do this by making use of the FS_ODD_RENAME flag if we just
    have nfs_rename() unconditionally do the d_move(). While there, we rename
    the flag to be more descriptive.

    OCFS2 uses this to protect that part of the rename operation with a cluster
    lock.

    Signed-off-by: Mark Fasheh
    Cc: Trond Myklebust
    Cc: Al Viro
    Cc: Christoph Hellwig
    Signed-off-by: Andrew Morton

    Mark Fasheh
     

23 Sep, 2006

13 commits

  • RFC3530 states that the registered port 2049 for the NFS protocol should be
    the default configuration in order to allow clients not to use the RPC
    binding protocols.
    If the mount program sends us a port=0, we therefore substitute port=2049.

    Signed-off-by: Trond Myklebust

    Trond Myklebust
     
  • Signed-off-by: Trond Myklebust

    Trond Myklebust
     
  • Signed-off-by: Trond Myklebust

    Trond Myklebust
     
  • 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
     
  • 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
     
  • Use the nominated dentry's superblock directly in the NFS statfs() op to get a
    file handle, rather than using s_root (which will become a dummy dentry in a
    future patch).

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

    David Howells
     
  • Generalise the nfs_client structure by:

    (1) Moving nfs_client to a more general place (nfs_fs_sb.h).

    (2) Renaming its maintenance routines to be non-NFS4 specific.

    (3) Move those maintenance routines to a new non-NFS4 specific file (client.c)
    and move the declarations to internal.h.

    (4) Make nfs_find/get_client() take a full sockaddr_in to include the port
    number (will be required for NFS2/3).

    (5) Make nfs_find/get_client() take the NFS protocol version (again will be
    required to differentiate NFS2, 3 & 4 client records).

    Also:

    (6) Make nfs_client construction proceed akin to inodes, marking them as under
    construction and providing a function to indicate completion.

    (7) Make nfs_get_client() wait interruptibly if it finds a client that it can
    share, but that client is currently being constructed.

    (8) Make nfs4_create_client() use (6) and (7) instead of locking cl_sem.

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

    David Howells
     
  • Return an error when starting the idmapping pipe so that we can detect it
    failing.

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

    David Howells
     
  • Rename nfs_server::nfs4_state to nfs_client as it will be used to represent the
    client state for NFS2 and NFS3 also.

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

    David Howells