![Stefan Weinhuber](/assets/img/avatar_default.png)
After the call to del_gendisk, the gendisk still holds a reference to its request_queue. We must not modify the gendisks queue pointer before the put_disk call, or the gendisk_release function cannot release the reference and the memory for the request_queue structure is lost. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
179 lines
4.6 KiB
C
179 lines
4.6 KiB
C
/*
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* Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
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* Horst Hummel <Horst.Hummel@de.ibm.com>
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* Carsten Otte <Cotte@de.ibm.com>
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* Martin Schwidefsky <schwidefsky@de.ibm.com>
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* Bugreports.to..: <Linux390@de.ibm.com>
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* Copyright IBM Corp. 1999, 2001
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*
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* gendisk related functions for the dasd driver.
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*
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*/
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#define KMSG_COMPONENT "dasd"
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#include <linux/interrupt.h>
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#include <linux/fs.h>
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#include <linux/blkpg.h>
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#include <asm/uaccess.h>
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/* This is ugly... */
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#define PRINTK_HEADER "dasd_gendisk:"
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#include "dasd_int.h"
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/*
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* Allocate and register gendisk structure for device.
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*/
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int dasd_gendisk_alloc(struct dasd_block *block)
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{
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struct gendisk *gdp;
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struct dasd_device *base;
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int len;
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/* Make sure the minor for this device exists. */
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base = block->base;
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if (base->devindex >= DASD_PER_MAJOR)
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return -EBUSY;
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gdp = alloc_disk(1 << DASD_PARTN_BITS);
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if (!gdp)
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return -ENOMEM;
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/* Initialize gendisk structure. */
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gdp->major = DASD_MAJOR;
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gdp->first_minor = base->devindex << DASD_PARTN_BITS;
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gdp->fops = &dasd_device_operations;
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gdp->driverfs_dev = &base->cdev->dev;
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/*
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* Set device name.
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* dasda - dasdz : 26 devices
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* dasdaa - dasdzz : 676 devices, added up = 702
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* dasdaaa - dasdzzz : 17576 devices, added up = 18278
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* dasdaaaa - dasdzzzz : 456976 devices, added up = 475252
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*/
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len = sprintf(gdp->disk_name, "dasd");
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if (base->devindex > 25) {
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if (base->devindex > 701) {
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if (base->devindex > 18277)
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len += sprintf(gdp->disk_name + len, "%c",
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'a'+(((base->devindex-18278)
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/17576)%26));
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len += sprintf(gdp->disk_name + len, "%c",
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'a'+(((base->devindex-702)/676)%26));
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}
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len += sprintf(gdp->disk_name + len, "%c",
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'a'+(((base->devindex-26)/26)%26));
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}
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len += sprintf(gdp->disk_name + len, "%c", 'a'+(base->devindex%26));
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if (base->features & DASD_FEATURE_READONLY ||
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test_bit(DASD_FLAG_DEVICE_RO, &base->flags))
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set_disk_ro(gdp, 1);
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dasd_add_link_to_gendisk(gdp, base);
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gdp->queue = block->request_queue;
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block->gdp = gdp;
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set_capacity(block->gdp, 0);
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add_disk(block->gdp);
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return 0;
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}
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/*
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* Unregister and free gendisk structure for device.
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*/
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void dasd_gendisk_free(struct dasd_block *block)
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{
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if (block->gdp) {
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del_gendisk(block->gdp);
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block->gdp->private_data = NULL;
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put_disk(block->gdp);
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block->gdp = NULL;
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}
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}
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/*
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* Trigger a partition detection.
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*/
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int dasd_scan_partitions(struct dasd_block *block)
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{
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struct block_device *bdev;
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bdev = bdget_disk(block->gdp, 0);
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if (!bdev || blkdev_get(bdev, FMODE_READ, NULL) < 0)
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return -ENODEV;
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/*
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* See fs/partition/check.c:register_disk,rescan_partitions
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* Can't call rescan_partitions directly. Use ioctl.
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*/
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ioctl_by_bdev(bdev, BLKRRPART, 0);
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/*
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* Since the matching blkdev_put call to the blkdev_get in
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* this function is not called before dasd_destroy_partitions
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* the offline open_count limit needs to be increased from
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* 0 to 1. This is done by setting device->bdev (see
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* dasd_generic_set_offline). As long as the partition
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* detection is running no offline should be allowed. That
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* is why the assignment to device->bdev is done AFTER
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* the BLKRRPART ioctl.
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*/
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block->bdev = bdev;
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return 0;
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}
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/*
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* Remove all inodes in the system for a device, delete the
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* partitions and make device unusable by setting its size to zero.
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*/
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void dasd_destroy_partitions(struct dasd_block *block)
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{
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/* The two structs have 168/176 byte on 31/64 bit. */
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struct blkpg_partition bpart;
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struct blkpg_ioctl_arg barg;
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struct block_device *bdev;
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/*
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* Get the bdev pointer from the device structure and clear
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* device->bdev to lower the offline open_count limit again.
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*/
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bdev = block->bdev;
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block->bdev = NULL;
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/*
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* See fs/partition/check.c:delete_partition
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* Can't call delete_partitions directly. Use ioctl.
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* The ioctl also does locking and invalidation.
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*/
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memset(&bpart, 0, sizeof(struct blkpg_partition));
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memset(&barg, 0, sizeof(struct blkpg_ioctl_arg));
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barg.data = (void __force __user *) &bpart;
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barg.op = BLKPG_DEL_PARTITION;
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for (bpart.pno = block->gdp->minors - 1; bpart.pno > 0; bpart.pno--)
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ioctl_by_bdev(bdev, BLKPG, (unsigned long) &barg);
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invalidate_partition(block->gdp, 0);
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/* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */
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blkdev_put(bdev, FMODE_READ);
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set_capacity(block->gdp, 0);
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}
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int dasd_gendisk_init(void)
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{
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int rc;
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/* Register to static dasd major 94 */
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rc = register_blkdev(DASD_MAJOR, "dasd");
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if (rc != 0) {
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pr_warning("Registering the device driver with major number "
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"%d failed\n", DASD_MAJOR);
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return rc;
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}
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return 0;
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}
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void dasd_gendisk_exit(void)
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{
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unregister_blkdev(DASD_MAJOR, "dasd");
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}
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