1 // SPDX-License-Identifier: GPL-2.0 2 /* 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 * Copyright IBM Corp. 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 <linux/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 50 /* 51 * Set device name. 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 56 */ 57 len = sprintf(gdp->disk_name, "dasd"); 58 if (base->devindex > 25) { 59 if (base->devindex > 701) { 60 if (base->devindex > 18277) 61 len += sprintf(gdp->disk_name + len, "%c", 62 'a'+(((base->devindex-18278) 63 /17576)%26)); 64 len += sprintf(gdp->disk_name + len, "%c", 65 'a'+(((base->devindex-702)/676)%26)); 66 } 67 len += sprintf(gdp->disk_name + len, "%c", 68 'a'+(((base->devindex-26)/26)%26)); 69 } 70 len += sprintf(gdp->disk_name + len, "%c", 'a'+(base->devindex%26)); 71 72 if (base->features & DASD_FEATURE_READONLY || 73 test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) 74 set_disk_ro(gdp, 1); 75 dasd_add_link_to_gendisk(gdp, base); 76 gdp->queue = block->request_queue; 77 block->gdp = gdp; 78 set_capacity(block->gdp, 0); 79 device_add_disk(&base->cdev->dev, 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->private_data = 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 int rc; 103 104 bdev = bdget_disk(block->gdp, 0); 105 if (!bdev) { 106 DBF_DEV_EVENT(DBF_ERR, block->base, "%s", 107 "scan partitions error, bdget returned NULL"); 108 return -ENODEV; 109 } 110 111 rc = blkdev_get(bdev, FMODE_READ, NULL); 112 if (rc < 0) { 113 DBF_DEV_EVENT(DBF_ERR, block->base, 114 "scan partitions error, blkdev_get returned %d", 115 rc); 116 return -ENODEV; 117 } 118 119 rc = blkdev_reread_part(bdev); 120 if (rc) 121 DBF_DEV_EVENT(DBF_ERR, block->base, 122 "scan partitions error, rc %d", rc); 123 124 /* 125 * Since the matching blkdev_put call to the blkdev_get in 126 * this function is not called before dasd_destroy_partitions 127 * the offline open_count limit needs to be increased from 128 * 0 to 1. This is done by setting device->bdev (see 129 * dasd_generic_set_offline). As long as the partition 130 * detection is running no offline should be allowed. That 131 * is why the assignment to device->bdev is done AFTER 132 * the BLKRRPART ioctl. 133 */ 134 block->bdev = bdev; 135 return 0; 136 } 137 138 /* 139 * Remove all inodes in the system for a device, delete the 140 * partitions and make device unusable by setting its size to zero. 141 */ 142 void dasd_destroy_partitions(struct dasd_block *block) 143 { 144 /* The two structs have 168/176 byte on 31/64 bit. */ 145 struct blkpg_partition bpart; 146 struct blkpg_ioctl_arg barg; 147 struct block_device *bdev; 148 149 /* 150 * Get the bdev pointer from the device structure and clear 151 * device->bdev to lower the offline open_count limit again. 152 */ 153 bdev = block->bdev; 154 block->bdev = NULL; 155 156 /* 157 * See fs/partition/check.c:delete_partition 158 * Can't call delete_partitions directly. Use ioctl. 159 * The ioctl also does locking and invalidation. 160 */ 161 memset(&bpart, 0, sizeof(struct blkpg_partition)); 162 memset(&barg, 0, sizeof(struct blkpg_ioctl_arg)); 163 barg.data = (void __force __user *) &bpart; 164 barg.op = BLKPG_DEL_PARTITION; 165 for (bpart.pno = block->gdp->minors - 1; bpart.pno > 0; bpart.pno--) 166 ioctl_by_bdev(bdev, BLKPG, (unsigned long) &barg); 167 168 invalidate_partition(block->gdp, 0); 169 /* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */ 170 blkdev_put(bdev, FMODE_READ); 171 set_capacity(block->gdp, 0); 172 } 173 174 int dasd_gendisk_init(void) 175 { 176 int rc; 177 178 /* Register to static dasd major 94 */ 179 rc = register_blkdev(DASD_MAJOR, "dasd"); 180 if (rc != 0) { 181 pr_warn("Registering the device driver with major number %d failed\n", 182 DASD_MAJOR); 183 return rc; 184 } 185 return 0; 186 } 187 188 void dasd_gendisk_exit(void) 189 { 190 unregister_blkdev(DASD_MAJOR, "dasd"); 191 } 192