block: don't set GD_NEED_PART_SCAN if scan partition failed

mainline inclusion
from mainline-v6.3-rc6
commit 3723091e
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7F7J3
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.4-rc7&id=3723091ea1884d599cc8b8bf719d6f42e8d4d8b1

--------------------------------

Currently if disk_scan_partitions() failed, GD_NEED_PART_SCAN will still
set, and partition scan will be proceed again when blkdev_get_by_dev()
is called. However, this will cause a problem that re-assemble partitioned
raid device will creat partition for underlying disk.

Test procedure:

mdadm -CR /dev/md0 -l 1 -n 2 /dev/sda /dev/sdb -e 1.0
sgdisk -n 0:0:+100MiB /dev/md0
blockdev --rereadpt /dev/sda
blockdev --rereadpt /dev/sdb
mdadm -S /dev/md0
mdadm -A /dev/md0 /dev/sda /dev/sdb

Test result: underlying disk partition and raid partition can be
observed at the same time

Note that this can still happen in come corner cases that
GD_NEED_PART_SCAN can be set for underlying disk while re-assemble raid
device.

Fixes: e5cfefa9 ("block: fix scan partition for exclusively open device again")
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NYu Kuai <yukuai3@huawei.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Conflicts:
  block/genhd.c
Signed-off-by: NLi Lingfeng <lilingfeng3@huawei.com>

block/genhd.c

@@ -770,6 +770,13 @@ int disk_scan_partitions(struct gendisk *disk, fmode_t mode)
 	else
 		blkdev_put(bdev, mode & ~FMODE_EXCL);
 
+	/*
+	 * If blkdev_get_by_dev() failed early, GD_NEED_PART_SCAN is still set,
+	 * and this will cause that re-assemble partitioned raid device will
+	 * creat partition for underlying disk.
+	 */
+	clear_bit(GD_NEED_PART_SCAN, &disk->state);
+
 	if (!(mode & FMODE_EXCL)) {
 		bd_abort_claiming(claim, claim, disk_scan_partitions);
 		bdput(claim);