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