performance/stat-prefetch: make lookup to wait for the completion of another lookup on same path if one is in progress.

- If current lookup (2) does not wait for completion of the lookup (1) which
    is in progress, there can be a race condition where (2) completes ahead of
    (1) and resuming all the waiting operations in the queue. When (1) returns,
    the original operation (eg., stat, chmod etc) might've already unwound and
    hence the frame would've been destroyed.

Signed-off-by: Raghavendra G <raghavendra@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 257 (Backport stat-prefetch to 2.0)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=257

0 files changed, 0 insertions, 0 deletions