From: Yu Kuai <yuku...@huawei.com>
- rename part_in_{flight, flight_rw} to bdev_count_{inflight, inflight_rw}
- export bdev_count_inflight, to fix a problem in mdraid that foreground
IO can be starved by background sync IO in later patches
Signed-off-by: Yu Kuai <yuku...@huawei.com>
---
block/blk-core.c | 2 +-
block/blk.h | 1 -
block/genhd.c | 22 ++++++++++++++++------
include/linux/part_stat.h | 2 ++
4 files changed, 19 insertions(+), 8 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index e8cc270a453f..b862c66018f2 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1018,7 +1018,7 @@ void update_io_ticks(struct block_device *part, unsigned
long now, bool end)
stamp = READ_ONCE(part->bd_stamp);
if (unlikely(time_after(now, stamp)) &&
likely(try_cmpxchg(&part->bd_stamp, &stamp, now)) &&
- (end || part_in_flight(part)))
+ (end || bdev_count_inflight(part)))
__part_stat_add(part, io_ticks, now - stamp);
if (bdev_is_partition(part)) {
diff --git a/block/blk.h b/block/blk.h
index 006e3be433d2..f476f233f195 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -418,7 +418,6 @@ void blk_apply_bdi_limits(struct backing_dev_info *bdi,
int blk_dev_init(void);
void update_io_ticks(struct block_device *part, unsigned long now, bool end);
-unsigned int part_in_flight(struct block_device *part);
static inline void req_set_nomerge(struct request_queue *q, struct request
*req)
{
diff --git a/block/genhd.c b/block/genhd.c
index 2470099b492b..fdaeafddfc4c 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -125,7 +125,7 @@ static void part_stat_read_all(struct block_device *part,
}
}
-static void part_in_flight_rw(struct block_device *part,
+static void bdev_count_inflight_rw(struct block_device *part,
unsigned int inflight[2], bool mq_driver)
{
int cpu;
@@ -147,14 +147,24 @@ static void part_in_flight_rw(struct block_device *part,
inflight[WRITE] = 0;
}
-unsigned int part_in_flight(struct block_device *part)
+/**
+ * bdev_count_inflight - get the number of inflight IOs for a block device.
+ *
+ * @part: the block device.
+ *
+ * Inflight here means started IO accounting, from bdev_start_io_acct() for
+ * bio-based block device, and from blk_account_io_start() for rq-based block
+ * device.
+ */
+unsigned int bdev_count_inflight(struct block_device *part)
{
unsigned int inflight[2] = {0};
- part_in_flight_rw(part, inflight, false);
+ bdev_count_inflight_rw(part, inflight, false);
return inflight[READ] + inflight[WRITE];
}
+EXPORT_SYMBOL_GPL(bdev_count_inflight);
/*
* Can be deleted altogether. Later.
@@ -1004,7 +1014,7 @@ ssize_t part_stat_show(struct device *dev,
struct disk_stats stat;
unsigned int inflight;
- inflight = part_in_flight(bdev);
+ inflight = bdev_count_inflight(bdev);
if (inflight) {
part_stat_lock();
update_io_ticks(bdev, jiffies, true);
@@ -1053,7 +1063,7 @@ ssize_t part_inflight_show(struct device *dev, struct
device_attribute *attr,
struct request_queue *q = bdev_get_queue(bdev);
unsigned int inflight[2] = {0};
- part_in_flight_rw(bdev, inflight, queue_is_mq(q));
+ bdev_count_inflight_rw(bdev, inflight, queue_is_mq(q));
return sysfs_emit(buf, "%8u %8u\n", inflight[READ], inflight[WRITE]);
}
@@ -1308,7 +1318,7 @@ static int diskstats_show(struct seq_file *seqf, void *v)
if (bdev_is_partition(hd) && !bdev_nr_sectors(hd))
continue;
- inflight = part_in_flight(hd);
+ inflight = bdev_count_inflight(hd);
if (inflight) {
part_stat_lock();
update_io_ticks(hd, jiffies, true);
diff --git a/include/linux/part_stat.h b/include/linux/part_stat.h
index c5e9cac0575e..eeeff2a04529 100644
--- a/include/linux/part_stat.h
+++ b/include/linux/part_stat.h
@@ -79,4 +79,6 @@ static inline void part_stat_set_all(struct block_device
*part, int value)
#define part_stat_local_read_cpu(part, field, cpu) \
local_read(&(part_stat_get_cpu(part, field, cpu)))
+unsigned int bdev_count_inflight(struct block_device *part);
+
#endif /* _LINUX_PART_STAT_H */
--
2.39.2
