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 #define KMSG_COMPONENT "dasd"
15
16 #include <linux/interrupt.h>
17 #include <linux/fs.h>
18 #include <linux/blkpg.h>
19
20 #include <asm/uaccess.h>
21
22 /* This is ugly... */
23 #define PRINTK_HEADER "dasd_gendisk:"
24
25 #include "dasd_int.h"
26
27 /*
28 * Allocate and register gendisk structure for device.
29 */
30 int dasd_gendisk_alloc(struct dasd_block *block)
31 {
32 struct gendisk *gdp;
33 struct dasd_device *base;
34 int len;
35
36 /* Make sure the minor for this device exists. */
37 base = block->base;
38 if (base->devindex >= DASD_PER_MAJOR)
39 return -EBUSY;
40
41 gdp = alloc_disk(1 << DASD_PARTN_BITS);
42 if (!gdp)
43 return -ENOMEM;
44
45 /* Initialize gendisk structure. */
46 gdp->major = DASD_MAJOR;
47 gdp->first_minor = base->devindex << DASD_PARTN_BITS;
48 gdp->fops = &dasd_device_operations;
49 gdp->driverfs_dev = &base->cdev->dev;
50
51 /*
52 * Set device name.
53 * dasda - dasdz : 26 devices
54 * dasdaa - dasdzz : 676 devices, added up = 702
55 * dasdaaa - dasdzzz : 17576 devices, added up = 18278
56 * dasdaaaa - dasdzzzz : 456976 devices, added up = 475252
57 */
58 len = sprintf(gdp->disk_name, "dasd");
59 if (base->devindex > 25) {
60 if (base->devindex > 701) {
61 if (base->devindex > 18277)
62 len += sprintf(gdp->disk_name + len, "%c",
63 'a'+(((base->devindex-18278)
64 /17576)%26));
65 len += sprintf(gdp->disk_name + len, "%c",
66 'a'+(((base->devindex-702)/676)%26));
67 }
68 len += sprintf(gdp->disk_name + len, "%c",
69 'a'+(((base->devindex-26)/26)%26));
70 }
71 len += sprintf(gdp->disk_name + len, "%c", 'a'+(base->devindex%26));
72
73 if (block->base->features & DASD_FEATURE_READONLY)
74 set_disk_ro(gdp, 1);
75 gdp->private_data = block;
76 gdp->queue = block->request_queue;
77 block->gdp = gdp;
78 set_capacity(block->gdp, 0);
79 add_disk(block->gdp);
80 return 0;
81 }
82
83 /*
84 * Unregister and free gendisk structure for device.
85 */
86 void dasd_gendisk_free(struct dasd_block *block)
87 {
88 if (block->gdp) {
89 del_gendisk(block->gdp);
90 block->gdp->queue = NULL;
91 put_disk(block->gdp);
92 block->gdp = NULL;
93 }
94 }
95
96 /*
97 * Trigger a partition detection.
98 */
99 int dasd_scan_partitions(struct dasd_block *block)
100 {
101 struct block_device *bdev;
102
103 bdev = bdget_disk(block->gdp, 0);
104 if (!bdev || blkdev_get(bdev, FMODE_READ) < 0)
105 return -ENODEV;
106 /*
107 * See fs/partition/check.c:register_disk,rescan_partitions
108 * Can't call rescan_partitions directly. Use ioctl.
109 */
110 ioctl_by_bdev(bdev, BLKRRPART, 0);
111 /*
112 * Since the matching blkdev_put call to the blkdev_get in
113 * this function is not called before dasd_destroy_partitions
114 * the offline open_count limit needs to be increased from
115 * 0 to 1. This is done by setting device->bdev (see
116 * dasd_generic_set_offline). As long as the partition
117 * detection is running no offline should be allowed. That
118 * is why the assignment to device->bdev is done AFTER
119 * the BLKRRPART ioctl.
120 */
121 block->bdev = bdev;
122 return 0;
123 }
124
125 /*
126 * Remove all inodes in the system for a device, delete the
127 * partitions and make device unusable by setting its size to zero.
128 */
129 void dasd_destroy_partitions(struct dasd_block *block)
130 {
131 /* The two structs have 168/176 byte on 31/64 bit. */
132 struct blkpg_partition bpart;
133 struct blkpg_ioctl_arg barg;
134 struct block_device *bdev;
135
136 /*
137 * Get the bdev pointer from the device structure and clear
138 * device->bdev to lower the offline open_count limit again.
139 */
140 bdev = block->bdev;
141 block->bdev = NULL;
142
143 /*
144 * See fs/partition/check.c:delete_partition
145 * Can't call delete_partitions directly. Use ioctl.
146 * The ioctl also does locking and invalidation.
147 */
148 memset(&bpart, 0, sizeof(struct blkpg_partition));
149 memset(&barg, 0, sizeof(struct blkpg_ioctl_arg));
150 barg.data = (void __force __user *) &bpart;
151 barg.op = BLKPG_DEL_PARTITION;
152 for (bpart.pno = block->gdp->minors - 1; bpart.pno > 0; bpart.pno--)
153 ioctl_by_bdev(bdev, BLKPG, (unsigned long) &barg);
154
155 invalidate_partition(block->gdp, 0);
156 /* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */
157 blkdev_put(bdev, FMODE_READ);
158 set_capacity(block->gdp, 0);
159 }
160
161 int dasd_gendisk_init(void)
162 {
163 int rc;
164
165 /* Register to static dasd major 94 */
166 rc = register_blkdev(DASD_MAJOR, "dasd");
167 if (rc != 0) {
168 pr_warning("Registering the device driver with major number "
169 "%d failed\n", DASD_MAJOR);
170 return rc;
171 }
172 return 0;
173 }
174
175 void dasd_gendisk_exit(void)
176 {
177 unregister_blkdev(DASD_MAJOR, "dasd");
178 }
179
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