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 gdp->driverfs_dev = &base->cdev->dev; 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 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->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 retry, rc; 103 104 retry = 5; 105 bdev = bdget_disk(block->gdp, 0); 106 if (!bdev) { 107 DBF_DEV_EVENT(DBF_ERR, block->base, "%s", 108 "scan partitions error, bdget returned NULL"); 109 return -ENODEV; 110 } 111 112 rc = blkdev_get(bdev, FMODE_READ, NULL); 113 if (rc < 0) { 114 DBF_DEV_EVENT(DBF_ERR, block->base, 115 "scan partitions error, blkdev_get returned %d", 116 rc); 117 return -ENODEV; 118 } 119 /* 120 * See fs/partition/check.c:register_disk,rescan_partitions 121 * Can't call rescan_partitions directly. Use ioctl. 122 */ 123 rc = ioctl_by_bdev(bdev, BLKRRPART, 0); 124 while (rc == -EBUSY && retry > 0) { 125 schedule(); 126 rc = ioctl_by_bdev(bdev, BLKRRPART, 0); 127 retry--; 128 DBF_DEV_EVENT(DBF_ERR, block->base, 129 "scan partitions error, retry %d rc %d", 130 retry, rc); 131 } 132 133 /* 134 * Since the matching blkdev_put call to the blkdev_get in 135 * this function is not called before dasd_destroy_partitions 136 * the offline open_count limit needs to be increased from 137 * 0 to 1. This is done by setting device->bdev (see 138 * dasd_generic_set_offline). As long as the partition 139 * detection is running no offline should be allowed. That 140 * is why the assignment to device->bdev is done AFTER 141 * the BLKRRPART ioctl. 142 */ 143 block->bdev = bdev; 144 return 0; 145 } 146 147 /* 148 * Remove all inodes in the system for a device, delete the 149 * partitions and make device unusable by setting its size to zero. 150 */ 151 void dasd_destroy_partitions(struct dasd_block *block) 152 { 153 /* The two structs have 168/176 byte on 31/64 bit. */ 154 struct blkpg_partition bpart; 155 struct blkpg_ioctl_arg barg; 156 struct block_device *bdev; 157 158 /* 159 * Get the bdev pointer from the device structure and clear 160 * device->bdev to lower the offline open_count limit again. 161 */ 162 bdev = block->bdev; 163 block->bdev = NULL; 164 165 /* 166 * See fs/partition/check.c:delete_partition 167 * Can't call delete_partitions directly. Use ioctl. 168 * The ioctl also does locking and invalidation. 169 */ 170 memset(&bpart, 0, sizeof(struct blkpg_partition)); 171 memset(&barg, 0, sizeof(struct blkpg_ioctl_arg)); 172 barg.data = (void __force __user *) &bpart; 173 barg.op = BLKPG_DEL_PARTITION; 174 for (bpart.pno = block->gdp->minors - 1; bpart.pno > 0; bpart.pno--) 175 ioctl_by_bdev(bdev, BLKPG, (unsigned long) &barg); 176 177 invalidate_partition(block->gdp, 0); 178 /* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */ 179 blkdev_put(bdev, FMODE_READ); 180 set_capacity(block->gdp, 0); 181 } 182 183 int dasd_gendisk_init(void) 184 { 185 int rc; 186 187 /* Register to static dasd major 94 */ 188 rc = register_blkdev(DASD_MAJOR, "dasd"); 189 if (rc != 0) { 190 pr_warning("Registering the device driver with major number " 191 "%d failed\n", DASD_MAJOR); 192 return rc; 193 } 194 return 0; 195 } 196 197 void dasd_gendisk_exit(void) 198 { 199 unregister_blkdev(DASD_MAJOR, "dasd"); 200 } 201