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 feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
44 gdp = alloc_disk(1 << DASD_PARTN_BITS);
48 /* Initialize gendisk structure. */
49 gdp->major = DASD_MAJOR;
50 gdp->first_minor = device->devindex << DASD_PARTN_BITS;
51 gdp->fops = &dasd_device_operations;
52 gdp->driverfs_dev = &device->cdev->dev;
56 * dasda - dasdz : 26 devices
57 * dasdaa - dasdzz : 676 devices, added up = 702
58 * dasdaaa - dasdzzz : 17576 devices, added up = 18278
59 * dasdaaaa - dasdzzzz : 456976 devices, added up = 475252
61 len = sprintf(gdp->disk_name, "dasd");
62 if (device->devindex > 25) {
63 if (device->devindex > 701) {
64 if (device->devindex > 18277)
65 len += sprintf(gdp->disk_name + len, "%c",
66 'a'+(((device->devindex-18278)
68 len += sprintf(gdp->disk_name + len, "%c",
69 'a'+(((device->devindex-702)/676)%26));
71 len += sprintf(gdp->disk_name + len, "%c",
72 'a'+(((device->devindex-26)/26)%26));
74 len += sprintf(gdp->disk_name + len, "%c", 'a'+(device->devindex%26));
76 sprintf(gdp->devfs_name, "dasd/%s", device->cdev->dev.bus_id);
80 gdp->private_data = device;
81 gdp->queue = device->request_queue;
83 set_capacity(device->gdp, 0);
84 add_disk(device->gdp);
89 * Unregister and free gendisk structure for device.
92 dasd_gendisk_free(struct dasd_device *device)
94 del_gendisk(device->gdp);
95 device->gdp->queue = 0;
96 put_disk(device->gdp);
101 * Trigger a partition detection.
104 dasd_scan_partitions(struct dasd_device * device)
106 struct block_device *bdev;
108 /* Make the disk known. */
109 set_capacity(device->gdp, device->blocks << device->s2b_shift);
110 bdev = bdget_disk(device->gdp, 0);
111 if (!bdev || blkdev_get(bdev, FMODE_READ, 1) < 0)
114 * See fs/partition/check.c:register_disk,rescan_partitions
115 * Can't call rescan_partitions directly. Use ioctl.
117 ioctl_by_bdev(bdev, BLKRRPART, 0);
119 * Since the matching blkdev_put call to the blkdev_get in
120 * this function is not called before dasd_destroy_partitions
121 * the offline open_count limit needs to be increased from
122 * 0 to 1. This is done by setting device->bdev (see
123 * dasd_generic_set_offline). As long as the partition
124 * detection is running no offline should be allowed. That
125 * is why the assignment to device->bdev is done AFTER
126 * the BLKRRPART ioctl.
133 * Remove all inodes in the system for a device, delete the
134 * partitions and make device unusable by setting its size to zero.
137 dasd_destroy_partitions(struct dasd_device * device)
139 /* The two structs have 168/176 byte on 31/64 bit. */
140 struct blkpg_partition bpart;
141 struct blkpg_ioctl_arg barg;
142 struct block_device *bdev;
145 * Get the bdev pointer from the device structure and clear
146 * device->bdev to lower the offline open_count limit again.
152 * See fs/partition/check.c:delete_partition
153 * Can't call delete_partitions directly. Use ioctl.
154 * The ioctl also does locking and invalidation.
156 memset(&bpart, 0, sizeof(struct blkpg_partition));
157 memset(&barg, 0, sizeof(struct blkpg_ioctl_arg));
159 barg.op = BLKPG_DEL_PARTITION;
160 for (bpart.pno = device->gdp->minors - 1; bpart.pno > 0; bpart.pno--)
161 ioctl_by_bdev(bdev, BLKPG, (unsigned long) &barg);
163 invalidate_partition(device->gdp, 0);
164 /* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */
166 set_capacity(device->gdp, 0);
170 dasd_gendisk_init(void)
174 /* Register to static dasd major 94 */
175 rc = register_blkdev(DASD_MAJOR, "dasd");
177 MESSAGE(KERN_WARNING,
178 "Couldn't register successfully to "
179 "major no %d", DASD_MAJOR);
186 dasd_gendisk_exit(void)
188 unregister_blkdev(DASD_MAJOR, "dasd");