1 /*
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
9 *
10 * gendisk related functions for the dasd driver.
11 *
12 */
13
14 #include <linux/interrupt.h>
15 #include <linux/fs.h>
16 #include <linux/blkpg.h>
17
18 #include <asm/uaccess.h>
19
20 /* This is ugly... */
21 #define PRINTK_HEADER "dasd_gendisk:"
22
23 #include "dasd_int.h"
24
25 /*
26 * Allocate and register gendisk structure for device.
27 */
28 int dasd_gendisk_alloc(struct dasd_block *block)
29 {
30 struct gendisk *gdp;
31 struct dasd_device *base;
32 int len;
33
34 /* Make sure the minor for this device exists. */
35 base = block->base;
36 if (base->devindex >= DASD_PER_MAJOR)
37 return -EBUSY;
38
39 gdp = alloc_disk(1 << DASD_PARTN_BITS);
40 if (!gdp)
41 return -ENOMEM;
42
43 /* Initialize gendisk structure. */
44 gdp->major = DASD_MAJOR;
45 gdp->first_minor = base->devindex << DASD_PARTN_BITS;
46 gdp->fops = &dasd_device_operations;
47 gdp->driverfs_dev = &base->cdev->dev;
48
49 /*
50 * Set device name.
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
55 */
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)
62 /17576)%26));
63 len += sprintf(gdp->disk_name + len, "%c",
64 'a'+(((base->devindex-702)/676)%26));
65 }
66 len += sprintf(gdp->disk_name + len, "%c",
67 'a'+(((base->devindex-26)/26)%26));
68 }
69 len += sprintf(gdp->disk_name + len, "%c", 'a'+(base->devindex%26));
70
71 if (block->base->features & DASD_FEATURE_READONLY)
72 set_disk_ro(gdp, 1);
73 gdp->private_data = block;
74 gdp->queue = block->request_queue;
75 block->gdp = gdp;
76 set_capacity(block->gdp, 0);
77 add_disk(block->gdp);
78 return 0;
79 }
80
81 /*
82 * Unregister and free gendisk structure for device.
83 */
84 void dasd_gendisk_free(struct dasd_block *block)
85 {
86 if (block->gdp) {
87 del_gendisk(block->gdp);
88 block->gdp->queue = NULL;
89 put_disk(block->gdp);
90 block->gdp = NULL;
91 }
92 }
93
94 /*
95 * Trigger a partition detection.
96 */
97 int dasd_scan_partitions(struct dasd_block *block)
98 {
99 struct block_device *bdev;
100
101 bdev = bdget_disk(block->gdp, 0);
102 if (!bdev || blkdev_get(bdev, FMODE_READ, 1) < 0)
103 return -ENODEV;
104 /*
105 * See fs/partition/check.c:register_disk,rescan_partitions
106 * Can't call rescan_partitions directly. Use ioctl.
107 */
108 ioctl_by_bdev(bdev, BLKRRPART, 0);
109 /*
110 * Since the matching blkdev_put call to the blkdev_get in
111 * this function is not called before dasd_destroy_partitions
112 * the offline open_count limit needs to be increased from
113 * 0 to 1. This is done by setting device->bdev (see
114 * dasd_generic_set_offline). As long as the partition
115 * detection is running no offline should be allowed. That
116 * is why the assignment to device->bdev is done AFTER
117 * the BLKRRPART ioctl.
118 */
119 block->bdev = bdev;
120 return 0;
121 }
122
123 /*
124 * Remove all inodes in the system for a device, delete the
125 * partitions and make device unusable by setting its size to zero.
126 */
127 void dasd_destroy_partitions(struct dasd_block *block)
128 {
129 /* The two structs have 168/176 byte on 31/64 bit. */
130 struct blkpg_partition bpart;
131 struct blkpg_ioctl_arg barg;
132 struct block_device *bdev;
133
134 /*
135 * Get the bdev pointer from the device structure and clear
136 * device->bdev to lower the offline open_count limit again.
137 */
138 bdev = block->bdev;
139 block->bdev = NULL;
140
141 /*
142 * See fs/partition/check.c:delete_partition
143 * Can't call delete_partitions directly. Use ioctl.
144 * The ioctl also does locking and invalidation.
145 */
146 memset(&bpart, 0, sizeof(struct blkpg_partition));
147 memset(&barg, 0, sizeof(struct blkpg_ioctl_arg));
148 barg.data = (void __force __user *) &bpart;
149 barg.op = BLKPG_DEL_PARTITION;
150 for (bpart.pno = block->gdp->minors - 1; bpart.pno > 0; bpart.pno--)
151 ioctl_by_bdev(bdev, BLKPG, (unsigned long) &barg);
152
153 invalidate_partition(block->gdp, 0);
154 /* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */
155 blkdev_put(bdev);
156 set_capacity(block->gdp, 0);
157 }
158
159 int dasd_gendisk_init(void)
160 {
161 int rc;
162
163 /* Register to static dasd major 94 */
164 rc = register_blkdev(DASD_MAJOR, "dasd");
165 if (rc != 0) {
166 MESSAGE(KERN_WARNING,
167 "Couldn't register successfully to "
168 "major no %d", DASD_MAJOR);
169 return rc;
170 }
171 return 0;
172 }
173
174 void dasd_gendisk_exit(void)
175 {
176 unregister_blkdev(DASD_MAJOR, "dasd");
177 }
178
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