The metadata read-ahead algorithm broke when switching from recursive to
non-recursive delete: the current algorithm reads ahead blocks at height
N - 1 while deallocating the blocks at hight N. However, deallocating
the blocks at height N requires a complete walk of the metadata tree,
not only down to height N - 1. Consequently, all blocks below height
N - 1 will be accessed without read-ahead.
Fix this by issuing read-aheads as early as possible, after each
metapath lookup.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
c3ce5aa9b0