From: Yu Kuai yukuai3@huawei.com
[ Upstream commit 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: e5cfefa97bcc ("block: fix scan partition for exclusively open device again") Reviewed-by: Jan Kara jack@suse.cz Reviewed-by: Ming Lei ming.lei@redhat.com Signed-off-by: Yu Kuai yukuai3@huawei.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- block/genhd.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/block/genhd.c b/block/genhd.c index 9c4c9aa559ab8..7082032636035 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -368,7 +368,6 @@ int disk_scan_partitions(struct gendisk *disk, fmode_t mode) if (disk->open_partitions) return -EBUSY;
- set_bit(GD_NEED_PART_SCAN, &disk->state); /* * If the device is opened exclusively by current thread already, it's * safe to scan partitons, otherwise, use bd_prepare_to_claim() to @@ -381,12 +380,19 @@ int disk_scan_partitions(struct gendisk *disk, fmode_t mode) return ret; }
+ set_bit(GD_NEED_PART_SCAN, &disk->state); bdev = blkdev_get_by_dev(disk_devt(disk), mode & ~FMODE_EXCL, NULL); if (IS_ERR(bdev)) ret = PTR_ERR(bdev); 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(disk->part0, disk_scan_partitions); return ret;