From 3642ef4d95699193c4a461862382e643ae3720f0 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Wed, 19 Oct 2022 20:15:16 +0800 Subject: [PATCH] blk-wbt: don't show valid wbt_lat_usec in sysfs while wbt is disabled MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, if wbt is initialized and then disabled by wbt_disable_default(), sysfs will still show valid wbt_lat_usec, which will confuse users that wbt is still enabled. This patch shows wbt_lat_usec as zero if it's disabled. Signed-off-by: Yu Kuai Reported-and-tested-by: Holger Hoffstätte Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20221019121518.3865235-5-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 3 +++ block/blk-wbt.c | 8 ++++++++ block/blk-wbt.h | 5 +++++ 3 files changed, 16 insertions(+) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index e71b3b43927c..7b98c7074771 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -470,6 +470,9 @@ static ssize_t queue_wb_lat_show(struct request_queue *q, char *page) if (!wbt_rq_qos(q)) return -EINVAL; + if (wbt_disabled(q)) + return sprintf(page, "0\n"); + return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000)); } diff --git a/block/blk-wbt.c b/block/blk-wbt.c index 4680691a96bc..07ed0b0aee1f 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -422,6 +422,14 @@ static void wbt_update_limits(struct rq_wb *rwb) rwb_wake_all(rwb); } +bool wbt_disabled(struct request_queue *q) +{ + struct rq_qos *rqos = wbt_rq_qos(q); + + return !rqos || RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT || + RQWB(rqos)->enable_state == WBT_STATE_OFF_MANUAL; +} + u64 wbt_get_min_lat(struct request_queue *q) { struct rq_qos *rqos = wbt_rq_qos(q); diff --git a/block/blk-wbt.h b/block/blk-wbt.h index 7fe98638fff5..e3ea6e7e2900 100644 --- a/block/blk-wbt.h +++ b/block/blk-wbt.h @@ -96,6 +96,7 @@ void wbt_enable_default(struct request_queue *); u64 wbt_get_min_lat(struct request_queue *q); void wbt_set_min_lat(struct request_queue *q, u64 val); +bool wbt_disabled(struct request_queue *); void wbt_set_write_cache(struct request_queue *, bool); @@ -127,6 +128,10 @@ static inline u64 wbt_default_latency_nsec(struct request_queue *q) { return 0; } +static inline bool wbt_disabled(struct request_queue *q) +{ + return true; +} #endif /* CONFIG_BLK_WBT */