From 35198e32300190d52e7f50413dde4f86dea1de92 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Tue, 17 Jan 2023 15:08:04 +0800 Subject: [PATCH] blk-iocost: read params inside lock in sysfs apis Otherwise, user might get abnormal values if params is updated concurrently. Signed-off-by: Yu Kuai Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20230117070806.3857142-4-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe --- block/blk-iocost.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 42a492096d3f..58ad4e5b2fff 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -3131,6 +3131,7 @@ static u64 ioc_qos_prfill(struct seq_file *sf, struct blkg_policy_data *pd, if (!dname) return 0; + spin_lock_irq(&ioc->lock); seq_printf(sf, "%s enable=%d ctrl=%s rpct=%u.%02u rlat=%u wpct=%u.%02u wlat=%u min=%u.%02u max=%u.%02u\n", dname, ioc->enabled, ioc->user_qos_params ? "user" : "auto", ioc->params.qos[QOS_RPPM] / 10000, @@ -3143,6 +3144,7 @@ static u64 ioc_qos_prfill(struct seq_file *sf, struct blkg_policy_data *pd, ioc->params.qos[QOS_MIN] % 10000 / 100, ioc->params.qos[QOS_MAX] / 10000, ioc->params.qos[QOS_MAX] % 10000 / 100); + spin_unlock_irq(&ioc->lock); return 0; } @@ -3322,12 +3324,14 @@ static u64 ioc_cost_model_prfill(struct seq_file *sf, if (!dname) return 0; + spin_lock_irq(&ioc->lock); seq_printf(sf, "%s ctrl=%s model=linear " "rbps=%llu rseqiops=%llu rrandiops=%llu " "wbps=%llu wseqiops=%llu wrandiops=%llu\n", dname, ioc->user_cost_model ? "user" : "auto", u[I_LCOEF_RBPS], u[I_LCOEF_RSEQIOPS], u[I_LCOEF_RRANDIOPS], u[I_LCOEF_WBPS], u[I_LCOEF_WSEQIOPS], u[I_LCOEF_WRANDIOPS]); + spin_unlock_irq(&ioc->lock); return 0; }