Initial import

1 files changed, 200 insertions, 0 deletions

diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c
new file mode 100644
index 000000000..90f39f79f
--- /dev/null
+++ b/drivers/s390/block/dasd_genhd.c
@@ -0,0 +1,200 @@
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ *		    Horst Hummel <Horst.Hummel@de.ibm.com>
+ *		    Carsten Otte <Cotte@de.ibm.com>
+ *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2001
+ *
+ * gendisk related functions for the dasd driver.
+ *
+ */
+
+#define KMSG_COMPONENT "dasd"
+
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/blkpg.h>
+
+#include <asm/uaccess.h>
+
+/* This is ugly... */
+#define PRINTK_HEADER "dasd_gendisk:"
+
+#include "dasd_int.h"
+
+/*
+ * Allocate and register gendisk structure for device.
+ */
+int dasd_gendisk_alloc(struct dasd_block *block)
+{
+	struct gendisk *gdp;
+	struct dasd_device *base;
+	int len;
+
+	/* Make sure the minor for this device exists. */
+	base = block->base;
+	if (base->devindex >= DASD_PER_MAJOR)
+		return -EBUSY;
+
+	gdp = alloc_disk(1 << DASD_PARTN_BITS);
+	if (!gdp)
+		return -ENOMEM;
+
+	/* Initialize gendisk structure. */
+	gdp->major = DASD_MAJOR;
+	gdp->first_minor = base->devindex << DASD_PARTN_BITS;
+	gdp->fops = &dasd_device_operations;
+	gdp->driverfs_dev = &base->cdev->dev;
+
+	/*
+	 * Set device name.
+	 *   dasda - dasdz : 26 devices
+	 *   dasdaa - dasdzz : 676 devices, added up = 702
+	 *   dasdaaa - dasdzzz : 17576 devices, added up = 18278
+	 *   dasdaaaa - dasdzzzz : 456976 devices, added up = 475252
+	 */
+	len = sprintf(gdp->disk_name, "dasd");
+	if (base->devindex > 25) {
+		if (base->devindex > 701) {
+			if (base->devindex > 18277)
+			        len += sprintf(gdp->disk_name + len, "%c",
+					       'a'+(((base->devindex-18278)
+						     /17576)%26));
+			len += sprintf(gdp->disk_name + len, "%c",
+				       'a'+(((base->devindex-702)/676)%26));
+		}
+		len += sprintf(gdp->disk_name + len, "%c",
+			       'a'+(((base->devindex-26)/26)%26));
+	}
+	len += sprintf(gdp->disk_name + len, "%c", 'a'+(base->devindex%26));
+
+	if (base->features & DASD_FEATURE_READONLY ||
+	    test_bit(DASD_FLAG_DEVICE_RO, &base->flags))
+		set_disk_ro(gdp, 1);
+	dasd_add_link_to_gendisk(gdp, base);
+	gdp->queue = block->request_queue;
+	block->gdp = gdp;
+	set_capacity(block->gdp, 0);
+	add_disk(block->gdp);
+	return 0;
+}
+
+/*
+ * Unregister and free gendisk structure for device.
+ */
+void dasd_gendisk_free(struct dasd_block *block)
+{
+	if (block->gdp) {
+		del_gendisk(block->gdp);
+		block->gdp->private_data = NULL;
+		put_disk(block->gdp);
+		block->gdp = NULL;
+	}
+}
+
+/*
+ * Trigger a partition detection.
+ */
+int dasd_scan_partitions(struct dasd_block *block)
+{
+	struct block_device *bdev;
+	int retry, rc;
+
+	retry = 5;
+	bdev = bdget_disk(block->gdp, 0);
+	if (!bdev) {
+		DBF_DEV_EVENT(DBF_ERR, block->base, "%s",
+			      "scan partitions error, bdget returned NULL");
+		return -ENODEV;
+	}
+
+	rc = blkdev_get(bdev, FMODE_READ, NULL);
+	if (rc < 0) {
+		DBF_DEV_EVENT(DBF_ERR, block->base,
+			      "scan partitions error, blkdev_get returned %d",
+			      rc);
+		return -ENODEV;
+	}
+	/*
+	 * See fs/partition/check.c:register_disk,rescan_partitions
+	 * Can't call rescan_partitions directly. Use ioctl.
+	 */
+	rc = ioctl_by_bdev(bdev, BLKRRPART, 0);
+	while (rc == -EBUSY && retry > 0) {
+		schedule();
+		rc = ioctl_by_bdev(bdev, BLKRRPART, 0);
+		retry--;
+		DBF_DEV_EVENT(DBF_ERR, block->base,
+			      "scan partitions error, retry %d rc %d",
+			      retry, rc);
+	}
+
+	/*
+	 * Since the matching blkdev_put call to the blkdev_get in
+	 * this function is not called before dasd_destroy_partitions
+	 * the offline open_count limit needs to be increased from
+	 * 0 to 1. This is done by setting device->bdev (see
+	 * dasd_generic_set_offline). As long as the partition
+	 * detection is running no offline should be allowed. That
+	 * is why the assignment to device->bdev is done AFTER
+	 * the BLKRRPART ioctl.
+	 */
+	block->bdev = bdev;
+	return 0;
+}
+
+/*
+ * Remove all inodes in the system for a device, delete the
+ * partitions and make device unusable by setting its size to zero.
+ */
+void dasd_destroy_partitions(struct dasd_block *block)
+{
+	/* The two structs have 168/176 byte on 31/64 bit. */
+	struct blkpg_partition bpart;
+	struct blkpg_ioctl_arg barg;
+	struct block_device *bdev;
+
+	/*
+	 * Get the bdev pointer from the device structure and clear
+	 * device->bdev to lower the offline open_count limit again.
+	 */
+	bdev = block->bdev;
+	block->bdev = NULL;
+
+	/*
+	 * See fs/partition/check.c:delete_partition
+	 * Can't call delete_partitions directly. Use ioctl.
+	 * The ioctl also does locking and invalidation.
+	 */
+	memset(&bpart, 0, sizeof(struct blkpg_partition));
+	memset(&barg, 0, sizeof(struct blkpg_ioctl_arg));
+	barg.data = (void __force __user *) &bpart;
+	barg.op = BLKPG_DEL_PARTITION;
+	for (bpart.pno = block->gdp->minors - 1; bpart.pno > 0; bpart.pno--)
+		ioctl_by_bdev(bdev, BLKPG, (unsigned long) &barg);
+
+	invalidate_partition(block->gdp, 0);
+	/* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */
+	blkdev_put(bdev, FMODE_READ);
+	set_capacity(block->gdp, 0);
+}
+
+int dasd_gendisk_init(void)
+{
+	int rc;
+
+	/* Register to static dasd major 94 */
+	rc = register_blkdev(DASD_MAJOR, "dasd");
+	if (rc != 0) {
+		pr_warning("Registering the device driver with major number "
+			   "%d failed\n", DASD_MAJOR);
+		return rc;
+	}
+	return 0;
+}
+
+void dasd_gendisk_exit(void)
+{
+	unregister_blkdev(DASD_MAJOR, "dasd");
+}