2 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
3 * Horst Hummel <Horst.Hummel@de.ibm.com>
4 * Carsten Otte <Cotte@de.ibm.com>
5 * Martin Schwidefsky <schwidefsky@de.ibm.com>
6 * Bugreports.to..: <Linux390@de.ibm.com>
7 * Copyright IBM Corp. 1999, 2001
9 * gendisk related functions for the dasd driver.
13 #define KMSG_COMPONENT "dasd"
15 #include <linux/interrupt.h>
17 #include <linux/blkpg.h>
19 #include <linux/uaccess.h>
22 #define PRINTK_HEADER "dasd_gendisk:"
27 * Allocate and register gendisk structure for device.
29 int dasd_gendisk_alloc(struct dasd_block *block)
32 struct dasd_device *base;
35 /* Make sure the minor for this device exists. */
37 if (base->devindex >= DASD_PER_MAJOR)
40 gdp = alloc_disk(1 << DASD_PARTN_BITS);
44 /* Initialize gendisk structure. */
45 gdp->major = DASD_MAJOR;
46 gdp->first_minor = base->devindex << DASD_PARTN_BITS;
47 gdp->fops = &dasd_device_operations;
51 * dasda - dasdz : 26 devices
52 * dasdaa - dasdzz : 676 devices, added up = 702
53 * dasdaaa - dasdzzz : 17576 devices, added up = 18278
54 * dasdaaaa - dasdzzzz : 456976 devices, added up = 475252
56 len = sprintf(gdp->disk_name, "dasd");
57 if (base->devindex > 25) {
58 if (base->devindex > 701) {
59 if (base->devindex > 18277)
60 len += sprintf(gdp->disk_name + len, "%c",
61 'a'+(((base->devindex-18278)
63 len += sprintf(gdp->disk_name + len, "%c",
64 'a'+(((base->devindex-702)/676)%26));
66 len += sprintf(gdp->disk_name + len, "%c",
67 'a'+(((base->devindex-26)/26)%26));
69 len += sprintf(gdp->disk_name + len, "%c", 'a'+(base->devindex%26));
71 if (base->features & DASD_FEATURE_READONLY ||
72 test_bit(DASD_FLAG_DEVICE_RO, &base->flags))
74 dasd_add_link_to_gendisk(gdp, base);
75 gdp->queue = block->request_queue;
77 set_capacity(block->gdp, 0);
78 device_add_disk(&base->cdev->dev, block->gdp);
83 * Unregister and free gendisk structure for device.
85 void dasd_gendisk_free(struct dasd_block *block)
88 del_gendisk(block->gdp);
89 block->gdp->private_data = NULL;
96 * Trigger a partition detection.
98 int dasd_scan_partitions(struct dasd_block *block)
100 struct block_device *bdev;
103 bdev = bdget_disk(block->gdp, 0);
105 DBF_DEV_EVENT(DBF_ERR, block->base, "%s",
106 "scan partitions error, bdget returned NULL");
110 rc = blkdev_get(bdev, FMODE_READ, NULL);
112 DBF_DEV_EVENT(DBF_ERR, block->base,
113 "scan partitions error, blkdev_get returned %d",
118 rc = blkdev_reread_part(bdev);
120 DBF_DEV_EVENT(DBF_ERR, block->base,
121 "scan partitions error, rc %d", rc);
124 * Since the matching blkdev_put call to the blkdev_get in
125 * this function is not called before dasd_destroy_partitions
126 * the offline open_count limit needs to be increased from
127 * 0 to 1. This is done by setting device->bdev (see
128 * dasd_generic_set_offline). As long as the partition
129 * detection is running no offline should be allowed. That
130 * is why the assignment to device->bdev is done AFTER
131 * the BLKRRPART ioctl.
138 * Remove all inodes in the system for a device, delete the
139 * partitions and make device unusable by setting its size to zero.
141 void dasd_destroy_partitions(struct dasd_block *block)
143 /* The two structs have 168/176 byte on 31/64 bit. */
144 struct blkpg_partition bpart;
145 struct blkpg_ioctl_arg barg;
146 struct block_device *bdev;
149 * Get the bdev pointer from the device structure and clear
150 * device->bdev to lower the offline open_count limit again.
156 * See fs/partition/check.c:delete_partition
157 * Can't call delete_partitions directly. Use ioctl.
158 * The ioctl also does locking and invalidation.
160 memset(&bpart, 0, sizeof(struct blkpg_partition));
161 memset(&barg, 0, sizeof(struct blkpg_ioctl_arg));
162 barg.data = (void __force __user *) &bpart;
163 barg.op = BLKPG_DEL_PARTITION;
164 for (bpart.pno = block->gdp->minors - 1; bpart.pno > 0; bpart.pno--)
165 ioctl_by_bdev(bdev, BLKPG, (unsigned long) &barg);
167 invalidate_partition(block->gdp, 0);
168 /* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */
169 blkdev_put(bdev, FMODE_READ);
170 set_capacity(block->gdp, 0);
173 int dasd_gendisk_init(void)
177 /* Register to static dasd major 94 */
178 rc = register_blkdev(DASD_MAJOR, "dasd");
180 pr_warn("Registering the device driver with major number %d failed\n",
187 void dasd_gendisk_exit(void)
189 unregister_blkdev(DASD_MAJOR, "dasd");