On 1/15/20 6:35 AM, Mikulas Patocka wrote: > Logical block size has type unsigned short. That means that it can be at > most 32768. However, there are architectures that can run with 64k pages > (for example arm64) and on these architectures, it may be possible to > create block devices with 64k block size. > > For exmaple (run this on an architecture with 64k pages): > # modprobe brd rd_size=1048576 > # dmsetup create cache --table "0 `blockdev --getsize /dev/ram0` writecache s /dev/ram0 /dev/ram1 65536 0" > # mkfs.ext4 -b 65536 /dev/mapper/cache > # mount -t ext4 /dev/mapper/cache /mnt/test > > Mount will fail with this error because it tries to read the superblock using 2-sector > access: > device-mapper: writecache: I/O is not aligned, sector 2, size 1024, block size 65536 > EXT4-fs (dm-0): unable to read superblock > > This patch changes the logical block size from unsigned short to unsigned > int to avoid the overflow. Thanks, applied. -- Jens Axboe
