From: Yu Kuai yukuai3@huawei.com
mainline inclusion from mainline-v6.2-rc1 commit 671fae5e51297fc76b3758ca2edd514858734a6a category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6HOKY CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h...
--------------------------------
Commit b5dc5d4d1f4f ("block,bfq: Disable writeback throttling") tries to disable wbt for bfq, it's done by calling wbt_disable_default() in bfq_init_queue(). However, wbt is still enabled if default elevator is bfq:
device_add_disk elevator_init_mq bfq_init_queue wbt_disable_default -> done nothing
blk_register_queue wbt_enable_default -> wbt is enabled
Fix the problem by adding a new flag ELEVATOR_FLAG_DISBALE_WBT, bfq will set the flag in bfq_init_queue, and following wbt_enable_default() won't enable wbt while the flag is set.
Signed-off-by: Yu Kuai yukuai3@huawei.com Reviewed-by: Christoph Hellwig hch@lst.de Link: https://lore.kernel.org/r/20221019121518.3865235-7-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe axboe@kernel.dk
Conflict: block/bfq-iosched.c block/blk-wbt.c block/elevator.h
Signed-off-by: Li Lingfeng lilingfeng3@huawei.com Reviewed-by: Hou Tao houtao1@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- block/blk-wbt.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/block/blk-wbt.c b/block/blk-wbt.c index 366d294a11ef..1a5ea2e0c055 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -711,11 +711,15 @@ void wbt_set_write_cache(struct request_queue *q, bool write_cache_on) */ void wbt_enable_default(struct request_queue *q) { - struct rq_qos *rqos = wbt_rq_qos(q); + struct rq_qos *rqos; + bool disable_flag = q->elevator && + !strcmp(q->elevator->type->elevator_name, "cfq");
/* Throttling already enabled? */ + rqos = wbt_rq_qos(q); if (rqos) { - if (RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT) + if (!disable_flag && + RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT) RQWB(rqos)->enable_state = WBT_STATE_ON_DEFAULT; return; } @@ -724,8 +728,9 @@ void wbt_enable_default(struct request_queue *q) if (!test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags)) return;
- if ((q->mq_ops && IS_ENABLED(CONFIG_BLK_WBT_MQ)) || - (q->request_fn && IS_ENABLED(CONFIG_BLK_WBT_SQ))) + if (((q->mq_ops && IS_ENABLED(CONFIG_BLK_WBT_MQ)) || + (q->request_fn && IS_ENABLED(CONFIG_BLK_WBT_SQ))) && + !disable_flag) wbt_init(q); } EXPORT_SYMBOL_GPL(wbt_enable_default);