diff mbox series

[-next,v2,4/9] blk-iocost: read params inside lock in sysfs apis

Message ID 20221130132156.2836184-5-linan122@huawei.com (mailing list archive)
State New, archived
Headers show
Series iocost bugfix | expand

Commit Message

Li Nan Nov. 30, 2022, 1:21 p.m. UTC 
From: Yu Kuai <yukuai3@huawei.com>

Otherwise, user might get abnormal values if params is updated
concurrently.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Li Nan <linan122@huawei.com>
---
 block/blk-iocost.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Tejun Heo Nov. 30, 2022, 8:16 p.m. UTC | #1 
On Wed, Nov 30, 2022 at 09:21:51PM +0800, Li Nan wrote:
> From: Yu Kuai <yukuai3@huawei.com>
> 
> Otherwise, user might get abnormal values if params is updated
> concurrently.
> 
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> Signed-off-by: Li Nan <linan122@huawei.com>

Acked-by: Tejun Heo <tj@kernel.org>
diff mbox series

Patch

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index bc6522bb314d..3a96cd557c47 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -3125,6 +3125,7 @@  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,
@@ -3137,6 +3138,7 @@  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;
 }
 
@@ -3319,12 +3321,14 @@  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;
 }