--- /dev/null
+/*
+ * 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");
+}
Code Review / kvmfornfv.git / blobdiff