[S390] dasd: Add support for raw ECKD access.
Normal I/O operations through the DASD device driver give only access
to the data fields of an ECKD device even for track based I/O.
This patch extends the DASD device driver to give access to whole
ECKD tracks including count, key and data fields.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 82d9ce3..4e266f4 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -369,6 +369,11 @@
device->state = DASD_STATE_ONLINE;
if (device->block) {
dasd_schedule_block_bh(device->block);
+ if ((device->features & DASD_FEATURE_USERAW)) {
+ disk = device->block->gdp;
+ kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
+ return 0;
+ }
disk = device->block->bdev->bd_disk;
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
while ((part = disk_part_iter_next(&piter)))
@@ -394,7 +399,7 @@
return rc;
}
device->state = DASD_STATE_READY;
- if (device->block) {
+ if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
disk = device->block->bdev->bd_disk;
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
while ((part = disk_part_iter_next(&piter)))
@@ -2258,8 +2263,20 @@
{
int max;
- blk_queue_logical_block_size(block->request_queue, block->bp_block);
- max = block->base->discipline->max_blocks << block->s2b_shift;
+ if (block->base->features & DASD_FEATURE_USERAW) {
+ /*
+ * the max_blocks value for raw_track access is 256
+ * it is higher than the native ECKD value because we
+ * only need one ccw per track
+ * so the max_hw_sectors are
+ * 2048 x 512B = 1024kB = 16 tracks
+ */
+ max = 2048;
+ } else {
+ max = block->base->discipline->max_blocks << block->s2b_shift;
+ }
+ blk_queue_logical_block_size(block->request_queue,
+ block->bp_block);
blk_queue_max_hw_sectors(block->request_queue, max);
blk_queue_max_segments(block->request_queue, -1L);
/* with page sized segments we can translate each segement into