1 /* 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 8 * 9 * gendisk related functions for the dasd driver. 10 * 11 */ 12 13 #define KMSG_COMPONENT "dasd" 14 15 #include <linux/interrupt.h> 16 #include <linux/fs.h> 17 #include <linux/blkpg.h> 18 19 #include <asm/uaccess.h> 20 21 /* This is ugly... */ 22 #define PRINTK_HEADER "dasd_gendisk:" 23 24 #include "dasd_int.h" 25 26 /* 27 * Allocate and register gendisk structure for device. 28 */ 29 int dasd_gendisk_alloc(struct dasd_block *block) 30 { 31 struct gendisk *gdp; 32 struct dasd_device *base; 33 int len; 34 35 /* Make sure the minor for this device exists. */ 36 base = block->base; 37 if (base->devindex >= DASD_PER_MAJOR) 38 return -EBUSY; 39 40 gdp = alloc_disk(1 << DASD_PARTN_BITS); 41 if (!gdp) 42 return -ENOMEM; 43 44 /* Initialize gendisk structure. */ 45 gdp->major = DASD_MAJOR; 46 gdp->first_minor = base->devindex << DASD_PARTN_BITS; 47 gdp->fops = &dasd_device_operations; 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 (base->features & DASD_FEATURE_READONLY || 72 test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) 73 set_disk_ro(gdp, 1); 74 dasd_add_link_to_gendisk(gdp, base); 75 gdp->queue = block->request_queue; 76 block->gdp = gdp; 77 set_capacity(block->gdp, 0); 78 device_add_disk(&base->cdev->dev, block->gdp); 79 return 0; 80 } 81 82 /* 83 * Unregister and free gendisk structure for device. 84 */ 85 void dasd_gendisk_free(struct dasd_block *block) 86 { 87 if (block->gdp) { 88 del_gendisk(block->gdp); 89 block->gdp->private_data = NULL; 90 put_disk(block->gdp); 91 block->gdp = NULL; 92 } 93 } 94 95 /* 96 * Trigger a partition detection. 97 */ 98 int dasd_scan_partitions(struct dasd_block *block) 99 { 100 struct block_device *bdev; 101 int rc; 102 103 bdev = bdget_disk(block->gdp, 0); 104 if (!bdev) { 105 DBF_DEV_EVENT(DBF_ERR, block->base, "%s", 106 "scan partitions error, bdget returned NULL"); 107 return -ENODEV; 108 } 109 110 rc = blkdev_get(bdev, FMODE_READ, NULL); 111 if (rc < 0) { 112 DBF_DEV_EVENT(DBF_ERR, block->base, 113 "scan partitions error, blkdev_get returned %d", 114 rc); 115 return -ENODEV; 116 } 117 118 rc = blkdev_reread_part(bdev); 119 if (rc) 120 DBF_DEV_EVENT(DBF_ERR, block->base, 121 "scan partitions error, rc %d", rc); 122 123 /* 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. 132 */ 133 block->bdev = bdev; 134 return 0; 135 } 136 137 /* 138 * Remove all inodes in the system for a device, delete the 139 * partitions and make device unusable by setting its size to zero. 140 */ 141 void dasd_destroy_partitions(struct dasd_block *block) 142 { 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; 147 148 /* 149 * Get the bdev pointer from the device structure and clear 150 * device->bdev to lower the offline open_count limit again. 151 */ 152 bdev = block->bdev; 153 block->bdev = NULL; 154 155 /* 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. 159 */ 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); 166 167 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); 171 } 172 173 int dasd_gendisk_init(void) 174 { 175 int rc; 176 177 /* Register to static dasd major 94 */ 178 rc = register_blkdev(DASD_MAJOR, "dasd"); 179 if (rc != 0) { 180 pr_warn("Registering the device driver with major number %d failed\n", 181 DASD_MAJOR); 182 return rc; 183 } 184 return 0; 185 } 186 187 void dasd_gendisk_exit(void) 188 { 189 unregister_blkdev(DASD_MAJOR, "dasd"); 190 } 191