• David S. Miller's avatar
    [SPARC64]: Abstract out mdesc accesses for better MD update handling. · 43fdf274
    David S. Miller authored
    Since we have to be able to handle MD updates, having an in-tree
    set of data structures representing the MD objects actually makes
    things more painful.
    
    The MD itself is easy to parse, and we can implement the existing
    interfaces using direct parsing of the MD binary image.
    
    The MD is now reference counted, so accesses have to now take the
    form:
    
    	handle = mdesc_grab();
    
    	... operations on MD ...
    
    	mdesc_release(handle);
    
    The only remaining issue are cases where code holds on to references
    to MD property values.  mdesc_get_property() returns a direct pointer
    to the property value, most cases just pull in the information they
    need and discard the pointer, but there are few that use the pointer
    directly over a long lifetime.  Those will be fixed up in a subsequent
    changeset.
    
    A preliminary handler for MD update events from domain services is
    there, it is rudimentry but it works and handles all of the reference
    counting.  It does not check the generation number of the MDs,
    and it does not generate a "add/delete" list for notification to
    interesting parties about MD changes but that will be forthcoming.
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    43fdf274
viohs.c 17.1 KB