block: BFQ: Refactor bfq_exit_icq() to silence sparse warning
Currently building for C=1 generates the following warning:
block/bfq-iosched.c:5498:9: warning: context imbalance in 'bfq_exit_icq' - different lock contexts for basic block
Refactor bfq_exit_icq() into a core part which loops for the actuators,
and only lock calling this routine when necessary.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240614090345.655716-4-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 4b88a54..36a4998 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5463,29 +5463,10 @@ static void bfq_exit_icq_bfqq(struct bfq_io_cq *bic, bool is_sync,
}
}
-static void bfq_exit_icq(struct io_cq *icq)
+static void _bfq_exit_icq(struct bfq_io_cq *bic, unsigned int num_actuators)
{
- struct bfq_io_cq *bic = icq_to_bic(icq);
- struct bfq_data *bfqd = bic_to_bfqd(bic);
- unsigned long flags;
- unsigned int act_idx;
- /*
- * If bfqd and thus bfqd->num_actuators is not available any
- * longer, then cycle over all possible per-actuator bfqqs in
- * next loop. We rely on bic being zeroed on creation, and
- * therefore on its unused per-actuator fields being NULL.
- */
- unsigned int num_actuators = BFQ_MAX_ACTUATORS;
struct bfq_iocq_bfqq_data *bfqq_data = bic->bfqq_data;
-
- /*
- * bfqd is NULL if scheduler already exited, and in that case
- * this is the last time these queues are accessed.
- */
- if (bfqd) {
- spin_lock_irqsave(&bfqd->lock, flags);
- num_actuators = bfqd->num_actuators;
- }
+ unsigned int act_idx;
for (act_idx = 0; act_idx < num_actuators; act_idx++) {
if (bfqq_data[act_idx].stable_merge_bfqq)
@@ -5494,9 +5475,30 @@ static void bfq_exit_icq(struct io_cq *icq)
bfq_exit_icq_bfqq(bic, true, act_idx);
bfq_exit_icq_bfqq(bic, false, act_idx);
}
+}
- if (bfqd)
+static void bfq_exit_icq(struct io_cq *icq)
+{
+ struct bfq_io_cq *bic = icq_to_bic(icq);
+ struct bfq_data *bfqd = bic_to_bfqd(bic);
+ unsigned long flags;
+
+ /*
+ * If bfqd and thus bfqd->num_actuators is not available any
+ * longer, then cycle over all possible per-actuator bfqqs in
+ * next loop. We rely on bic being zeroed on creation, and
+ * therefore on its unused per-actuator fields being NULL.
+ *
+ * bfqd is NULL if scheduler already exited, and in that case
+ * this is the last time these queues are accessed.
+ */
+ if (bfqd) {
+ spin_lock_irqsave(&bfqd->lock, flags);
+ _bfq_exit_icq(bic, bfqd->num_actuators);
spin_unlock_irqrestore(&bfqd->lock, flags);
+ } else {
+ _bfq_exit_icq(bic, BFQ_MAX_ACTUATORS);
+ }
}
/*
