s390/dasd: add ioctl to perform a swap of the drivers copy pair
authorStefan Haberland <sth@linux.ibm.com>
Tue, 20 Sep 2022 19:26:14 +0000 (21:26 +0200)
committerJens Axboe <axboe@kernel.dk>
Wed, 21 Sep 2022 14:32:51 +0000 (08:32 -0600)
commit112ff512fc654d7066936dcc06f77cc60471fdb4
tree90c5b2025828765325a0d0562366242e6ead5ed6
parent413862caad6fe7fddec639219bccfdab60333551
s390/dasd: add ioctl to perform a swap of the drivers copy pair

The newly defined ioctl BIODASDCOPYPAIRSWAP takes a structure that
specifies a copy pair that should be swapped. It will call the device
discipline function to perform the swap operation.

The structure looks as followed:

struct dasd_copypair_swap_data_t {
       char primary[20];
       char secondary[20];
       __u8 reserved[64];
};

where primary is the old primary device that will be replaced by the
secondary device. The old primary will become a secondary device
afterwards.

Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Link: https://lore.kernel.org/r/20220920192616.808070-6-sth@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
arch/s390/include/uapi/asm/dasd.h
drivers/s390/block/dasd_ioctl.c