Merge branch 'tape-block-sizes'

Merge branch 'tape-block-sizes'

Jan Höppner says:

====================

The tape device driver is limited to a block size of 65535 bytes since a
single CCW can only transfer up to 64K-1 bytes (The count field is a
16bit value). This series introduces data chaining for all read/write
functions to support block sizes larger than 65535.

The tape device type 3490 (emulated) and 3590/3592 can handle up to
256K. [1]

[1] https://www.ibm.com/docs/en/zos/3.1.0?topic=blksize-system-determined-block-size

====================

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>