block, bfq: make sure queue budgets are not below service received

With some unlucky sequences of events, the function bfq_updated_next_req
updates the current budget of a bfq_queue to a lower value than the
service received by the queue using such a budget. Unfortunately, if
this happens, then the return value of the function bfq_bfqq_budget_left
becomes inconsistent. This commit solves this problem by lower-bounding
the budget computed in bfq_updated_next_req to the service currently
charged to the queue.

Signed-off-by: Paolo Valente <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions