[PATCH 1/4] s390/dasd: Fix gendisk parent after copy pair swap

Stefan Haberland
2025-11-26T16:06:42Z

After a copy pair swap the block device's "device" symlink points to
the secondary CCW device, but the gendisk's parent remained the
primary, leaving /sys/block/<dasdx> under the wrong parent.

Move the gendisk to the secondary's device with device_move(), keeping
the sysfs topology consistent after the swap.

Fixes: 413862caad6f ("s390/dasd: add copy pair swap capability")
Cc: stable@vger.kernel.org #6.1
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
---
drivers/s390/block/dasd_eckd.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 88fa17aea2ec..ec0c62e5ef73 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -6150,6 +6150,7 @@ static int dasd_eckd_copy_pair_swap(struct dasd_device *device, char *prim_busid
struct dasd_copy_relation *copy;
struct dasd_block *block;
struct gendisk *gdp;
+ int rc;

copy = device->copy;
if (!copy)
@@ -6184,6 +6185,13 @@ static int dasd_eckd_copy_pair_swap(struct dasd_device *device, char *prim_busid
/* swap blocklayer device link */
gdp = block->gdp;
dasd_add_link_to_gendisk(gdp, secondary);
+ rc = device_move(disk_to_dev(gdp), &secondary->cdev->dev, DPM_ORDER_NONE);
+ if (rc) {
+ dev_err(&primary->cdev->dev,
+ "copy_pair_swap: moving blockdevice parent %s->%s failed (%d)\n",
+ dev_name(&primary->cdev->dev),
+ dev_name(&secondary->cdev->dev), rc);
+ }

/* re-enable device */
dasd_device_remove_stop_bits(primary, DASD_STOPPED_PPRC);
--
2.51.0