From: Yu Kuai yukuai3@huawei.com
mainline inclusion from mainline-v6.2-rc1 commit 3642ef4d95699193c4a461862382e643ae3720f0 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6Z1UG CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h...
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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 Signed-off-by: Li Lingfeng lilingfeng3@huawei.com --- 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 169e63ee05cb..e612afe1cdc6 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -461,6 +461,9 @@ 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 6fc76432db84..cce5a4cb51c4 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -419,6 +419,14 @@ 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 c4d365b9f7b0..824047c395ff 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);
@@ -130,6 +131,10 @@ 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 */