2 * File...........: linux/drivers/s390/block/dasd_genhd.c
3 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4 * Horst Hummel <Horst.Hummel@de.ibm.com>
5 * Carsten Otte <Cotte@de.ibm.com>
6 * Martin Schwidefsky <schwidefsky@de.ibm.com>
7 * Bugreports.to..: <Linux390@de.ibm.com>
8 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
10 * gendisk related functions for the dasd driver.
15 #include <linux/config.h>
16 #include <linux/interrupt.h>
18 #include <linux/blkpg.h>
20 #include <asm/uaccess.h>
23 #define PRINTK_HEADER "dasd_gendisk:"
28 * Allocate and register gendisk structure for device.
31 dasd_gendisk_alloc(struct dasd_device *device)
36 /* Make sure the minor for this device exists. */
37 if (device->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 = device->devindex << DASD_PARTN_BITS;
47 gdp->fops = &dasd_device_operations;
48 gdp->driverfs_dev = &device->cdev->dev;
52 * dasda - dasdz : 26 devices
53 * dasdaa - dasdzz : 676 devices, added up = 702
54 * dasdaaa - dasdzzz : 17576 devices, added up = 18278
55 * dasdaaaa - dasdzzzz : 456976 devices, added up = 475252
57 len = sprintf(gdp->disk_name, "dasd");
58 if (device->devindex > 25) {
59 if (device->devindex > 701) {
60 if (device->devindex > 18277)
61 len += sprintf(gdp->disk_name + len, "%c",
62 'a'+(((device->devindex-18278)
64 len += sprintf(gdp->disk_name + len, "%c",
65 'a'+(((device->devindex-702)/676)%26));
67 len += sprintf(gdp->disk_name + len, "%c",
68 'a'+(((device->devindex-26)/26)%26));
70 len += sprintf(gdp->disk_name + len, "%c", 'a'+(device->devindex%26));
72 sprintf(gdp->devfs_name, "dasd/%s", device->cdev->dev.bus_id);
74 if (device->features & DASD_FEATURE_READONLY)
76 gdp->private_data = device;
77 gdp->queue = device->request_queue;
79 set_capacity(device->gdp, 0);
80 add_disk(device->gdp);
85 * Unregister and free gendisk structure for device.
88 dasd_gendisk_free(struct dasd_device *device)
90 del_gendisk(device->gdp);
91 device->gdp->queue = 0;
92 put_disk(device->gdp);
97 * Trigger a partition detection.
100 dasd_scan_partitions(struct dasd_device * device)
102 struct block_device *bdev;
104 /* Make the disk known. */
105 set_capacity(device->gdp, device->blocks << device->s2b_shift);
106 bdev = bdget_disk(device->gdp, 0);
107 if (!bdev || blkdev_get(bdev, FMODE_READ, 1) < 0)
110 * See fs/partition/check.c:register_disk,rescan_partitions
111 * Can't call rescan_partitions directly. Use ioctl.
113 ioctl_by_bdev(bdev, BLKRRPART, 0);
115 * Since the matching blkdev_put call to the blkdev_get in
116 * this function is not called before dasd_destroy_partitions
117 * the offline open_count limit needs to be increased from
118 * 0 to 1. This is done by setting device->bdev (see
119 * dasd_generic_set_offline). As long as the partition
120 * detection is running no offline should be allowed. That
121 * is why the assignment to device->bdev is done AFTER
122 * the BLKRRPART ioctl.
129 * Remove all inodes in the system for a device, delete the
130 * partitions and make device unusable by setting its size to zero.
133 dasd_destroy_partitions(struct dasd_device * device)
135 /* The two structs have 168/176 byte on 31/64 bit. */
136 struct blkpg_partition bpart;
137 struct blkpg_ioctl_arg barg;
138 struct block_device *bdev;
141 * Get the bdev pointer from the device structure and clear
142 * device->bdev to lower the offline open_count limit again.
148 * See fs/partition/check.c:delete_partition
149 * Can't call delete_partitions directly. Use ioctl.
150 * The ioctl also does locking and invalidation.
152 memset(&bpart, 0, sizeof(struct blkpg_partition));
153 memset(&barg, 0, sizeof(struct blkpg_ioctl_arg));
155 barg.op = BLKPG_DEL_PARTITION;
156 for (bpart.pno = device->gdp->minors - 1; bpart.pno > 0; bpart.pno--)
157 ioctl_by_bdev(bdev, BLKPG, (unsigned long) &barg);
159 invalidate_partition(device->gdp, 0);
160 /* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */
162 set_capacity(device->gdp, 0);
166 dasd_gendisk_init(void)
170 /* Register to static dasd major 94 */
171 rc = register_blkdev(DASD_MAJOR, "dasd");
173 MESSAGE(KERN_WARNING,
174 "Couldn't register successfully to "
175 "major no %d", DASD_MAJOR);
182 dasd_gendisk_exit(void)
184 unregister_blkdev(DASD_MAJOR, "dasd");