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authorYu Kuai <yukuai3@huawei.com>2022-10-19 14:15:16 +0200
committerJens Axboe <axboe@kernel.dk>2022-10-24 02:59:17 +0200
commit3642ef4d95699193c4a461862382e643ae3720f0 (patch)
treee0a696d7266ff27dadb46349b6bde22da71ea6e1
parentblk-wbt: make enable_state more accurate (diff)
downloadlinux-3642ef4d95699193c4a461862382e643ae3720f0.tar.xz
linux-3642ef4d95699193c4a461862382e643ae3720f0.zip
blk-wbt: don't show valid wbt_lat_usec in sysfs while wbt is disabled
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 <yukuai3@huawei.com> Reported-and-tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221019121518.3865235-5-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/blk-sysfs.c3
-rw-r--r--block/blk-wbt.c8
-rw-r--r--block/blk-wbt.h5
3 files changed, 16 insertions, 0 deletions
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 */