[PATCH 5.14 044/432] block: bfq: fix bfq_set_next_ioprio_data()

Greg Kroah-Hartman
2021-09-16T17:14:20Z

From: Damien Le Moal <damien.lemoal@wdc.com>

commit a680dd72ec336b81511e3bff48efac6dbfa563e7 upstream.

For a request that has a priority level equal to or larger than
IOPRIO_BE_NR, bfq_set_next_ioprio_data() prints a critical warning but
defaults to setting the request new_ioprio field to IOPRIO_BE_NR. This
is not consistent with the warning and the allowed values for priority
levels. Fix this by setting the request new_ioprio field to
IOPRIO_BE_NR - 1, the lowest priority level allowed.

Cc: <stable@vger.kernel.org>
Fixes: aee69d78dec0 ("block, bfq: introduce the BFQ-v0 I/O scheduler as an extra scheduler")
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210811033702.368488-2-damien.lemoal@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
block/bfq-iosched.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5296,7 +5296,7 @@ bfq_set_next_ioprio_data(struct bfq_queu
if (bfqq->new_ioprio >= IOPRIO_BE_NR) {
pr_crit("bfq_set_next_ioprio_data: new_ioprio %d\n",
bfqq->new_ioprio);
- bfqq->new_ioprio = IOPRIO_BE_NR;
+ bfqq->new_ioprio = IOPRIO_BE_NR - 1;
}

bfqq->entity.new_weight = bfq_ioprio_to_weight(bfqq->new_ioprio);