Commit b5cfbd35 authored by Yufen Yu's avatar Yufen Yu Committed by Jens Axboe
Browse files

block: check disk exist before trying to add partition 



If disk have been deleted, we should return fail for ioctl
BLKPG_DEL_PARTITION. Otherwise, the directory /sys/class/block
may remain invalid symlinks file. The race as following:

blkdev_open
				del_gendisk
				    disk->flags &= ~GENHD_FL_UP;
				    blk_drop_partitions
blkpg_ioctl
    bdev_add_partition
    add_partition
        device_add
	    device_add_class_symlinks

ioctl may add_partition after del_gendisk() have tried to delete
partitions. Then, symlinks file will be created.

Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarYufen Yu <yuyufen@huawei.com>
Link: https://lore.kernel.org/r/20210610023241.3646241-1-yuyufen@huawei.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent efee99e6

block/partitions/core.c

+16 −7
Original line number Diff line number Diff line
@@ -453,17 +453,26 @@ int bdev_add_partition(struct block_device *bdev, int partno, 
		sector_t start, sector_t length)

{

	struct block_device *part;

	struct gendisk *disk = bdev->bd_disk;

	int ret;



	mutex_lock(&bdev->bd_disk->open_mutex);

	if (partition_overlaps(bdev->bd_disk, start, length, -1)) {

		mutex_unlock(&bdev->bd_disk->open_mutex);

		return -EBUSY;

	mutex_lock(&disk->open_mutex);

	if (!(disk->flags & GENHD_FL_UP)) {

		ret = -ENXIO;

		goto out;

	}



	part = add_partition(bdev->bd_disk, partno, start, length,

	if (partition_overlaps(disk, start, length, -1)) {

		ret = -EBUSY;

		goto out;

	}



	part = add_partition(disk, partno, start, length,

			ADDPART_FLAG_NONE, NULL);

	mutex_unlock(&bdev->bd_disk->open_mutex);

	return PTR_ERR_OR_ZERO(part);

	ret = PTR_ERR_OR_ZERO(part);

out:

	mutex_unlock(&disk->open_mutex);

	return ret;

}



int bdev_del_partition(struct block_device *bdev, int partno)