• Steven Whitehouse's avatar
    GFS2: Replace rgblk_search with gfs2_rbm_find · 5b924ae2
    Steven Whitehouse authored
    
    
    This is part of a series of patches which are introducing the
    gfs2_rbm structure throughout the block allocation code. The
    main aim of this part is to create a search function which can
    deal directly with struct gfs2_rbm. In this case it specifies
    the initial position at which to start the search and also the
    point at which the search terminates.
    
    The net result of this is to clean up the search code and make
    it rather more readable, and the various possible exceptions which
    may occur during the search are partitioned into their own functions.
    
    There are some bug fixes too. We should not be checking the reservations
    while allocating extents - the time for that is when we are searching
    for where to put the extent, not when we've already made that decision.
    
    Also, rgblk_search had two uses, and in only one of those cases did
    it make sense to check for reservations. This is fixed in the new
    gfs2_rbm_find function, which has a cleaner interface.
    
    The reservation checking has been improved by always checking for
    contiguous reservations, and returning the first free block after
    all contiguous reservations. This is done under the spin lock to
    ensure consistancy of the tree.
    
    The allocation of extents is now in all cases done by the existing
    allocation code, and if there is an active reservation, that is updated
    after the fact. Again this is done under the spin lock, since it entails
    changing the lookup key for the reservation in question.
    Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    5b924ae2