If the index allocated by idr_alloc greater than MINORMASK >> part_shift,
the device number will overflow, resulting in failure to create a block
device.
Fix it by imiting the size of the max allocation.
Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230605122159.2134384-1-zhongjinghua@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
if (err == -ENOSPC)
err = -EEXIST;
} else {
- err = idr_alloc(&nbd_index_idr, nbd, 0, 0, GFP_KERNEL);
+ err = idr_alloc(&nbd_index_idr, nbd, 0,
+ (MINORMASK >> part_shift) + 1, GFP_KERNEL);
if (err >= 0)
index = err;
}