features/quota: Fix race-condition while resuming stub.

- call-stub is resumed in fops calling quota_check_limit and quota_check_limit
    when validate_count is zero, indicating no pending validates. During
    validates, validate_count was decremented in quota_validate_cbk, but check
    for validate_count being zero was done in quota_check_limit (which is
    called by quota_validate_cbk). Hence there is a time window b/w decrementing
    validate_count in quota_validate_cbk and checking whether
    validate_count is zero in quota_check_limit, during which if the
    control is passed to code in fop checking for validate_count being zero,
    same stub will be resumed twice - once in fop and once in quota_check_limit.

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

BUG: 2686 ([glusterfs-3.2.0qa8]: nfs server crashed)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2686

0 files changed, 0 insertions, 0 deletions