[S390] dcssblk: prevent early access without own make_request function

When loading a dcss segment with the dcssblk driver, sometimes the
following kind of message appears:

bio too big device dcssblk0 (8 > 0)
Buffer I/O error on device dcssblk0, logical block 172016
..

The fix is to move the disk registration after setting the
make_request function, to avoid calls into generic_make_request
for dcssblock without having the make_request function set up
properly.

Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 5e083d1f57e7..15a5789b7734 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -472,11 +472,11 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
         if (rc)
                 goto unregister_dev;
 
-        add_disk(dev_info->gd);
-
         blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request);
         blk_queue_hardsect_size(dev_info->dcssblk_queue, 4096);
 
+        add_disk(dev_info->gd);
+
         switch (dev_info->segment_type) {
                 case SEG_TYPE_SR:
                 case SEG_TYPE_ER: