[PATCH] s390: use normal switch statement for ioctls in dasd_ioctlc

Add an ->ioctl method to the dasd_discipline structure.  This allows to apply
the same kind of cleanups the last patch applied to dasd_ioctl.c to
dasd_eckd.c (the only dasd discipline with special ioctls) aswell.

Again lots of code removed.  During auditing the ioctls I found two fishy
return value propagations from copy_{from,to}_user, maintainers please check
those, I've marked them with XXX comments.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index e3ad34686444..bb6caf46bbd9 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -448,7 +448,14 @@ dasd_ioctl(struct inode *inode, struct file *file,
         case DASDAPIVER:
                 return dasd_ioctl_api_version(argp);
         default:
-                /* resort to the deprecated dynamic ioctl list */
+                /* if the discipline has an ioctl method try it. */
+                if (device->discipline->ioctl) {
+                        int rval = device->discipline->ioctl(device, cmd, argp);
+                        if (rval != -ENOIOCTLCMD)
+                                return rval;
+                }
+
+                /* else resort to the deprecated dynamic ioctl list */
                 list_for_each_entry(ioctl, &dasd_ioctl_list, list) {
                         if (ioctl->no == cmd) {
                                 /* Found a matching ioctl. Call it. */