• Bob Peterson's avatar
    GFS2: Drop inadequate rgrps from the reservation tree · 1330edbe
    Bob Peterson authored
    This is just basically a resend of a patch I posted earlier.
    It didn't change from its original, except in diff offsets, etc:
    This patch fixes a bug in the GFS2 block allocation code. The problem
    starts if a process already has a multi-block reservation, but for
    some reason, another process disqualifies it from further allocations.
    For example, the other process might set on the GFS2_RDF_ERROR bit.
    The process holding the reservation jumps to label skip_rgrp, but
    that label comes after the code that removes the reservation from the
    tree. Therefore, the no longer usable reservation is not removed from
    the rgrp's reservations tree; it's lost. Eventually, the lost reservation
    causes the count of reserved blocks to get off, and eventually that
    causes a BUG_ON(rs->rs_rbm.rgd->rd_reserved < rs->rs_free) to trigger.
    This patch moves the call to after label skip_rgrp so that the
    disqualified reservation is properly removed from the tree, thus keeping
    the rgrp rd_reserved count sane.
    Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
    Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>