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: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Link: https://lore.kernel.org/r/20210610023241.3646241-1-yuyufen@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/partitions/core.c b/block/partitions/core.c
index 347c56a..ed78cdf 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -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)