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 */ 30int 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 (base->features & DASD_FEATURE_READONLY || 74 test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) 75 set_disk_ro(gdp, 1); 76 gdp->private_data = block; 77 gdp->queue = block->request_queue; 78 block->gdp = gdp; 79 set_capacity(block->gdp, 0); 80 add_disk(block->gdp); 81 return 0; 82} 83 84/* 85 * Unregister and free gendisk structure for device. 86 */ 87void dasd_gendisk_free(struct dasd_block *block) 88{ 89 if (block->gdp) { 90 del_gendisk(block->gdp); 91 block->gdp->queue = NULL; 92 block->gdp->private_data = NULL; 93 put_disk(block->gdp); 94 block->gdp = NULL; 95 } 96} 97 98/* 99 * Trigger a partition detection. 100 */ 101int dasd_scan_partitions(struct dasd_block *block) 102{ 103 struct block_device *bdev; 104 105 bdev = bdget_disk(block->gdp, 0); 106 if (!bdev || blkdev_get(bdev, FMODE_READ) < 0) 107 return -ENODEV; 108 /* 109 * See fs/partition/check.c:register_disk,rescan_partitions 110 * Can't call rescan_partitions directly. Use ioctl. 111 */ 112 ioctl_by_bdev(bdev, BLKRRPART, 0); 113 /* 114 * Since the matching blkdev_put call to the blkdev_get in 115 * this function is not called before dasd_destroy_partitions 116 * the offline open_count limit needs to be increased from 117 * 0 to 1. This is done by setting device->bdev (see 118 * dasd_generic_set_offline). As long as the partition 119 * detection is running no offline should be allowed. That 120 * is why the assignment to device->bdev is done AFTER 121 * the BLKRRPART ioctl. 122 */ 123 block->bdev = bdev; 124 return 0; 125} 126 127/* 128 * Remove all inodes in the system for a device, delete the 129 * partitions and make device unusable by setting its size to zero. 130 */ 131void dasd_destroy_partitions(struct dasd_block *block) 132{ 133 /* The two structs have 168/176 byte on 31/64 bit. */ 134 struct blkpg_partition bpart; 135 struct blkpg_ioctl_arg barg; 136 struct block_device *bdev; 137 138 /* 139 * Get the bdev pointer from the device structure and clear 140 * device->bdev to lower the offline open_count limit again. 141 */ 142 bdev = block->bdev; 143 block->bdev = NULL; 144 145 /* 146 * See fs/partition/check.c:delete_partition 147 * Can't call delete_partitions directly. Use ioctl. 148 * The ioctl also does locking and invalidation. 149 */ 150 memset(&bpart, 0, sizeof(struct blkpg_partition)); 151 memset(&barg, 0, sizeof(struct blkpg_ioctl_arg)); 152 barg.data = (void __force __user *) &bpart; 153 barg.op = BLKPG_DEL_PARTITION; 154 for (bpart.pno = block->gdp->minors - 1; bpart.pno > 0; bpart.pno--) 155 ioctl_by_bdev(bdev, BLKPG, (unsigned long) &barg); 156 157 invalidate_partition(block->gdp, 0); 158 /* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */ 159 blkdev_put(bdev, FMODE_READ); 160 set_capacity(block->gdp, 0); 161} 162 163int dasd_gendisk_init(void) 164{ 165 int rc; 166 167 /* Register to static dasd major 94 */ 168 rc = register_blkdev(DASD_MAJOR, "dasd"); 169 if (rc != 0) { 170 pr_warning("Registering the device driver with major number " 171 "%d failed\n", DASD_MAJOR); 172 return rc; 173 } 174 return 0; 175} 176 177void dasd_gendisk_exit(void) 178{ 179 unregister_blkdev(DASD_MAJOR, "dasd"); 180} 181