26 Sep, 2014

1 commit


19 Oct, 2011

1 commit


03 Apr, 2009

6 commits

  • Add read context retention so that FS-Cache can call back into NFS when a read
    operation on the cache fails EIO rather than reading data. This permits NFS to
    then fetch the data from the server instead using the appropriate security
    context.

    Signed-off-by: David Howells
    Acked-by: Steve Dickson
    Acked-by: Trond Myklebust
    Acked-by: Al Viro
    Tested-by: Daire Byrne

    David Howells
     
  • Invalidate the FsCache page flags on the pages belonging to an inode when the
    cache backing that NFS inode is removed.

    This allows a live cache to be withdrawn.

    Signed-off-by: David Howells
    Acked-by: Steve Dickson
    Acked-by: Trond Myklebust
    Acked-by: Al Viro
    Tested-by: Daire Byrne

    David Howells
     
  • Define and create inode-level cache data storage objects (as managed by
    nfs_inode structs).

    Each inode-level object is created in a superblock-level index object and is
    itself a data storage object into which pages from the inode are stored.

    The inode object key is the NFS file handle for the inode.

    The inode object is given coherency data to carry in the auxiliary data
    permitted by the cache. This is a sequence made up of:

    (1) i_mtime from the NFS inode.

    (2) i_ctime from the NFS inode.

    (3) i_size from the NFS inode.

    (4) change_attr from the NFSv4 attribute data.

    As the cache is a persistent cache, the auxiliary data is checked when a new
    NFS in-memory inode is set up that matches an already existing data storage
    object in the cache. If the coherency data is the same, the on-disk object is
    retained and used; if not, it is scrapped and a new one created.

    Signed-off-by: David Howells
    Acked-by: Steve Dickson
    Acked-by: Trond Myklebust
    Acked-by: Al Viro
    Tested-by: Daire Byrne

    David Howells
     
  • Define and create superblock-level cache index objects (as managed by
    nfs_server structs).

    Each superblock object is created in a server level index object and is itself
    an index into which inode-level objects are inserted.

    Ideally there would be one superblock-level object per server, and the former
    would be folded into the latter; however, since the "nosharecache" option
    exists this isn't possible.

    The superblock object key is a sequence consisting of:

    (1) Certain superblock s_flags.

    (2) Various connection parameters that serve to distinguish superblocks for
    sget().

    (3) The volume FSID.

    (4) The security flavour.

    (5) The uniquifier length.

    (6) The uniquifier text. This is normally an empty string, unless the fsc=xyz
    mount option was used to explicitly specify a uniquifier.

    The key blob is of variable length, depending on the length of (6).

    The superblock object is given no coherency data to carry in the auxiliary data
    permitted by the cache. It is assumed that the superblock is always coherent.

    This patch also adds uniquification handling such that two otherwise identical
    superblocks, at least one of which is marked "nosharecache", won't end up
    trying to share the on-disk cache. It will be possible to manually provide a
    uniquifier through a mount option with a later patch to avoid the error
    otherwise produced.

    Signed-off-by: David Howells
    Acked-by: Steve Dickson
    Acked-by: Trond Myklebust
    Acked-by: Al Viro
    Tested-by: Daire Byrne

    David Howells
     
  • Define and create server-level cache index objects (as managed by nfs_client
    structs).

    Each server object is created in the NFS top-level index object and is itself
    an index into which superblock-level objects are inserted.

    Ideally there would be one superblock-level object per server, and the former
    would be folded into the latter; however, since the "nosharecache" option
    exists this isn't possible.

    The server object key is a sequence consisting of:

    (1) NFS version

    (2) Server address family (eg: AF_INET or AF_INET6)

    (3) Server port.

    (4) Server IP address.

    The key blob is of variable length, depending on the length of (4).

    The server object is given no coherency data to carry in the auxiliary data
    permitted by the cache.

    Signed-off-by: David Howells
    Acked-by: Steve Dickson
    Acked-by: Trond Myklebust
    Acked-by: Al Viro
    Tested-by: Daire Byrne

    David Howells
     
  • Register NFS for caching and retrieve the top-level cache index object cookie.

    Signed-off-by: David Howells
    Acked-by: Steve Dickson
    Acked-by: Trond Myklebust
    Acked-by: Al Viro
    Tested-by: Daire Byrne

    David Howells