[PATCH 10/11] block: simplify diskstats_show

Christoph Hellwig
2021-04-06T06:23:33Z

Just use xa_for_each to iterate over the partitions as there is no need
to grab a reference to each partition.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/genhd.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 5726714ef82fcf..cbfe1ff19360b3 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1236,11 +1236,11 @@ const struct device_type disk_type = {
static int diskstats_show(struct seq_file *seqf, void *v)
{
struct gendisk *gp = v;
- struct disk_part_iter piter;
struct block_device *hd;
char buf[BDEVNAME_SIZE];
unsigned int inflight;
struct disk_stats stat;
+ unsigned long idx;

/*
if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
@@ -1250,8 +1250,10 @@ static int diskstats_show(struct seq_file *seqf, void *v)
"\n\n");
*/

- disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
- while ((hd = disk_part_iter_next(&piter))) {
+ rcu_read_lock();
+ xa_for_each(&gp->part_tbl, idx, hd) {
+ if (bdev_is_partition(hd) && !bdev_nr_sectors(hd))
+ continue;
part_stat_read_all(hd, &stat);
if (queue_is_mq(gp->queue))
inflight = blk_mq_in_flight(gp->queue, hd);
@@ -1294,7 +1296,7 @@ static int diskstats_show(struct seq_file *seqf, void *v)
NSEC_PER_MSEC)
);
}
- disk_part_iter_exit(&piter);
+ rcu_read_unlock();

return 0;
}
--
2.30.1