• Steven Whitehouse's avatar
    GFS2: Make resource groups "append only" during life of fs · 8339ee54
    Steven Whitehouse authored
    Since we have ruled out supporting online filesystem shrink,
    it is possible to make the resource group list append only
    during the life of a super block. This gives several benefits:
    Firstly, we only need to read new rindex elements as they are added
    rather than needing to reread the whole rindex file each time one
    element is added.
    Secondly, the rindex glock can be held for much shorter periods of
    time, and is completely removed from the fast path for allocations.
    The lock is taken in shared mode only when updating the resource
    groups when the first allocation occurs, and after a grow has
    taken place.
    Thirdly, this results in a reduction in code size, and everything
    gets a lot simpler to understand in this area.
    Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>