• David Howells's avatar
    WorkStruct: Pass the work_struct pointer instead of context data · 65f27f38
    David Howells authored
    
    
    Pass the work_struct pointer to the work function rather than context data.
    The work function can use container_of() to work out the data.
    
    For the cases where the container of the work_struct may go away the moment the
    pending bit is cleared, it is made possible to defer the release of the
    structure by deferring the clearing of the pending bit.
    
    To make this work, an extra flag is introduced into the management side of the
    work_struct.  This governs auto-release of the structure upon execution.
    
    Ordinarily, the work queue executor would release the work_struct for further
    scheduling or deallocation by clearing the pending bit prior to jumping to the
    work function.  This means that, unless the driver makes some guarantee itself
    that the work_struct won't go away, the work function may not access anything
    else in the work_struct or its container lest they be deallocated..  This is a
    problem if the auxiliary data is taken away (as done by the last patch).
    
    However, if the pending bit is *not* cleared before jumping to the work
    function, then the work function *may* access the work_struct and its container
    with no problems.  But then the work function must itself release the
    work_struct by calling work_release().
    
    In most cases, automatic release is fine, so this is the default.  Special
    initiators exist for the non-auto-release case (ending in _NAR).
    Signed-Off-By: default avatarDavid Howells <dhowells@redhat.com>
    65f27f38