• Chuck Lever's avatar
    SUNRPC: Generalize the RPC buffer allocation API · 5fe6eaa1
    Chuck Lever authored
    xprtrdma needs to allocate the Call and Reply buffers separately.
    TBH, the reliance on using a single buffer for the pair of XDR
    buffers is transport implementation-specific.
    
    Transports that want to allocate separate Call and Reply buffers
    will ignore the "size" argument anyway.  Don't bother passing it.
    
    The buf_alloc method can't return two pointers. Instead, make the
    method's return value an error code, and set the rq_buffer pointer
    in the method itself.
    
    This gives call_allocate an opportunity to terminate an RPC instead
    of looping forever when a permanent problem occurs. If a request is
    just bogus, or the transport is in a state where it can't allocate
    resources for any request, there needs to be a way to kill the RPC
    right there and not loop.
    
    This immediately fixes a rare problem in the backchannel send path,
    which loops if the server happens to send a CB request whose
    call+reply size is larger than a page (which it shouldn't do yet).
    
    One more issue: looks like xprt_inject_disconnect was incorrectly
    placed in the failure path in call_allocate. It needs to be in the
    success path, as it is for other call-sites.
    Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
    Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
    5fe6eaa1
transport.c 22.4 KB