block: simplify show_partition

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>
Link: https://lore.kernel.org/r/20210406062303.811835-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/genhd.c b/block/genhd.c
index 409ff47..5726714 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -907,8 +907,8 @@ static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
 static int show_partition(struct seq_file *seqf, void *v)
 {
        struct gendisk *sgp = v;
-       struct disk_part_iter piter;
        struct block_device *part;
+       unsigned long idx;
        char buf[BDEVNAME_SIZE];
 
        /* Don't show non-partitionable removeable devices or empty devices */
@@ -918,15 +918,16 @@ static int show_partition(struct seq_file *seqf, void *v)
        if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
                return 0;
 
-       /* show the full disk and all non-0 size partitions of it */
-       disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
-       while ((part = disk_part_iter_next(&piter)))
+       rcu_read_lock();
+       xa_for_each(&sgp->part_tbl, idx, part) {
+               if (!bdev_nr_sectors(part))
+                       continue;
                seq_printf(seqf, "%4d  %7d %10llu %s\n",
                           MAJOR(part->bd_dev), MINOR(part->bd_dev),
                           bdev_nr_sectors(part) >> 1,
                           disk_name(sgp, part->bd_partno, buf));
-       disk_part_iter_exit(&piter);
-
+       }
+       rcu_read_unlock();
        return 0;
 }