On Tue 08-06-21 17:27:07, Yufen Yu wrote:
> 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.
>
> Signed-off-by: Yufen Yu <yuyufen@xxxxxxxxxx>
Looks good to me. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> block/partitions/core.c | 19 ++++++++++++++-----
> 1 file changed, 14 insertions(+), 5 deletions(-)
>
> diff --git a/block/partitions/core.c b/block/partitions/core.c
> index dc60ecf46fe6..58662a0f48e4 100644
> --- a/block/partitions/core.c
> +++ b/block/partitions/core.c
> @@ -449,17 +449,26 @@ 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_mutex);
> - if (partition_overlaps(bdev->bd_disk, start, length, -1)) {
> - mutex_unlock(&bdev->bd_mutex);
> - return -EBUSY;
> + 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);
> + ret = PTR_ERR_OR_ZERO(part);
> +out:
> mutex_unlock(&bdev->bd_mutex);
> - return PTR_ERR_OR_ZERO(part);
> + return ret;
> }
>
> int bdev_del_partition(struct block_device *bdev, int partno)
> --
> 2.25.4
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
