diff options
Diffstat (limited to 'drivers/s390/block/dasd_genhd.c')
| -rw-r--r-- | drivers/s390/block/dasd_genhd.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c new file mode 100644 index 000000000000..1d52db406b2e --- /dev/null +++ b/drivers/s390/block/dasd_genhd.c @@ -0,0 +1,185 @@ +/* + * File...........: linux/drivers/s390/block/dasd_genhd.c + * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com> + * Horst Hummel <Horst.Hummel@de.ibm.com> + * Carsten Otte <Cotte@de.ibm.com> + * Martin Schwidefsky <schwidefsky@de.ibm.com> + * Bugreports.to..: <Linux390@de.ibm.com> + * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001 + * + * gendisk related functions for the dasd driver. + * + * $Revision: 1.48 $ + */ + +#include <linux/config.h> +#include <linux/interrupt.h> +#include <linux/fs.h> +#include <linux/blkpg.h> + +#include <asm/uaccess.h> + +/* This is ugly... */ +#define PRINTK_HEADER "dasd_gendisk:" + +#include "dasd_int.h" + +/* + * Allocate and register gendisk structure for device. + */ +int +dasd_gendisk_alloc(struct dasd_device *device) +{ + struct gendisk *gdp; + int len; + + /* Make sure the minor for this device exists. */ + if (device->devindex >= DASD_PER_MAJOR) + return -EBUSY; + + gdp = alloc_disk(1 << DASD_PARTN_BITS); + if (!gdp) + return -ENOMEM; + + /* Initialize gendisk structure. */ + gdp->major = DASD_MAJOR; + gdp->first_minor = device->devindex << DASD_PARTN_BITS; + gdp->fops = &dasd_device_operations; + gdp->driverfs_dev = &device->cdev->dev; + + /* + * Set device name. + * dasda - dasdz : 26 devices + * dasdaa - dasdzz : 676 devices, added up = 702 + * dasdaaa - dasdzzz : 17576 devices, added up = 18278 + * dasdaaaa - dasdzzzz : 456976 devices, added up = 475252 + */ + len = sprintf(gdp->disk_name, "dasd"); + if (device->devindex > 25) { + if (device->devindex > 701) { + if (device->devindex > 18277) + len += sprintf(gdp->disk_name + len, "%c", + 'a'+(((device->devindex-18278) + /17576)%26)); + len += sprintf(gdp->disk_name + len, "%c", + 'a'+(((device->devindex-702)/676)%26)); + } + len += sprintf(gdp->disk_name + len, "%c", + 'a'+(((device->devindex-26)/26)%26)); + } + len += sprintf(gdp->disk_name + len, "%c", 'a'+(device->devindex%26)); + + sprintf(gdp->devfs_name, "dasd/%s", device->cdev->dev.bus_id); + + if (test_bit(DASD_FLAG_RO, &device->flags)) + set_disk_ro(gdp, 1); + gdp->private_data = device; + gdp->queue = device->request_queue; + device->gdp = gdp; + set_capacity(device->gdp, 0); + add_disk(device->gdp); + return 0; +} + +/* + * Unregister and free gendisk structure for device. + */ +void +dasd_gendisk_free(struct dasd_device *device) +{ + del_gendisk(device->gdp); + device->gdp->queue = 0; + put_disk(device->gdp); + device->gdp = 0; +} + +/* + * Trigger a partition detection. + */ +int +dasd_scan_partitions(struct dasd_device * device) +{ + struct block_device *bdev; + + /* Make the disk known. */ + set_capacity(device->gdp, device->blocks << device->s2b_shift); + bdev = bdget_disk(device->gdp, 0); + if (!bdev || blkdev_get(bdev, FMODE_READ, 1) < 0) + return -ENODEV; + /* + * See fs/partition/check.c:register_disk,rescan_partitions + * Can't call rescan_partitions directly. Use ioctl. + */ + ioctl_by_bdev(bdev, BLKRRPART, 0); + /* + * Since the matching blkdev_put call to the blkdev_get in + * this function is not called before dasd_destroy_partitions + * the offline open_count limit needs to be increased from + * 0 to 1. This is done by setting device->bdev (see + * dasd_generic_set_offline). As long as the partition + * detection is running no offline should be allowed. That + * is why the assignment to device->bdev is done AFTER + * the BLKRRPART ioctl. + */ + device->bdev = bdev; + return 0; +} + +/* + * Remove all inodes in the system for a device, delete the + * partitions and make device unusable by setting its size to zero. + */ +void +dasd_destroy_partitions(struct dasd_device * device) +{ + /* The two structs have 168/176 byte on 31/64 bit. */ + struct blkpg_partition bpart; + struct blkpg_ioctl_arg barg; + struct block_device *bdev; + + /* + * Get the bdev pointer from the device structure and clear + * device->bdev to lower the offline open_count limit again. + */ + bdev = device->bdev; + device->bdev = 0; + + /* + * See fs/partition/check.c:delete_partition + * Can't call delete_partitions directly. Use ioctl. + * The ioctl also does locking and invalidation. + */ + memset(&bpart, 0, sizeof(struct blkpg_partition)); + memset(&barg, 0, sizeof(struct blkpg_ioctl_arg)); + barg.data = &bpart; + barg.op = BLKPG_DEL_PARTITION; + for (bpart.pno = device->gdp->minors - 1; bpart.pno > 0; bpart.pno--) + ioctl_by_bdev(bdev, BLKPG, (unsigned long) &barg); + + invalidate_partition(device->gdp, 0); + /* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */ + blkdev_put(bdev); + set_capacity(device->gdp, 0); +} + +int +dasd_gendisk_init(void) +{ + int rc; + + /* Register to static dasd major 94 */ + rc = register_blkdev(DASD_MAJOR, "dasd"); + if (rc != 0) { + MESSAGE(KERN_WARNING, + "Couldn't register successfully to " + "major no %d", DASD_MAJOR); + return rc; + } + return 0; +} + +void +dasd_gendisk_exit(void) +{ + unregister_blkdev(DASD_MAJOR, "dasd"); +} |