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s390/dasd: remove ioctl_by_bdev calls

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The IBM partition parser requires device type specific information only
available to the DASD driver to correctly register partitions. The
current approach of using ioctl_by_bdev with a fake user space pointer
is discouraged.

Fix this by replacing IOCTL calls with direct in-kernel function calls.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Stefan Haberland 2020-05-19 16:22:59 +02:00 committed by Jens Axboe
parent 9353848c65
commit 26d7e28e38
4 changed files with 62 additions and 6 deletions
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1
MAINTAINERS
View File

@ -14628,6 +14628,7 @@ S: Supported
W: http://www.ibm.com/developerworks/linux/linux390/
F: block/partitions/ibm.c
F: drivers/s390/block/dasd*
F: include/linux/dasd_mod.h
S390 IOMMU (PCI)
M: Gerald Schaefer <gerald.schaefer@de.ibm.com>

24
block/partitions/ibm.c
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@ -13,10 +13,11 @@
#include <asm/ebcdic.h>
#include <linux/uaccess.h>
#include <asm/vtoc.h>
#include <linux/module.h>
#include <linux/dasd_mod.h>
#include "check.h"
union label_t {
struct vtoc_volume_label_cdl vol;
struct vtoc_volume_label_ldl lnx;
@ -288,7 +289,9 @@ static int find_cms1_partitions(struct parsed_partitions *state,
*/
int ibm_partition(struct parsed_partitions *state)
{
int (*fn)(struct gendisk *disk, dasd_information2_t *info);
struct block_device *bdev = state->bdev;
struct gendisk *disk = bdev->bd_disk;
int blocksize, res;
loff_t i_size, offset, size;
dasd_information2_t *info;
@ -299,24 +302,31 @@ int ibm_partition(struct parsed_partitions *state)
union label_t *label;
res = 0;
if (!disk->fops->getgeo)
goto out_exit;
fn = symbol_get(dasd_biodasdinfo);
if (!fn)
goto out_exit;
blocksize = bdev_logical_block_size(bdev);
if (blocksize <= 0)
goto out_exit;
goto out_symbol;
i_size = i_size_read(bdev->bd_inode);
if (i_size == 0)
goto out_exit;
goto out_symbol;
info = kmalloc(sizeof(dasd_information2_t), GFP_KERNEL);
if (info == NULL)
goto out_exit;
goto out_symbol;
geo = kmalloc(sizeof(struct hd_geometry), GFP_KERNEL);
if (geo == NULL)
goto out_nogeo;
label = kmalloc(sizeof(union label_t), GFP_KERNEL);
if (label == NULL)
goto out_nolab;
if (ioctl_by_bdev(bdev, HDIO_GETGEO, (unsigned long)geo) != 0)
/* set start if not filled by getgeo function e.g. virtblk */
geo->start = get_start_sect(bdev);
if (disk->fops->getgeo(bdev, geo))
goto out_freeall;
if (ioctl_by_bdev(bdev, BIODASDINFO2, (unsigned long)info) != 0) {
if (fn(disk, info)) {
kfree(info);
info = NULL;
}
@ -359,6 +369,8 @@ out_nolab:
kfree(geo);
out_nogeo:
kfree(info);
out_symbol:
symbol_put(dasd_biodasdinfo);
out_exit:
return res;
}

34
drivers/s390/block/dasd_ioctl.c
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@ -22,6 +22,7 @@
#include <asm/schid.h>
#include <asm/cmb.h>
#include <linux/uaccess.h>
#include <linux/dasd_mod.h>
/* This is ugly... */
#define PRINTK_HEADER "dasd_ioctl:"
@ -664,3 +665,36 @@ int dasd_ioctl(struct block_device *bdev, fmode_t mode,
dasd_put_device(base);
return rc;
}
/**
* dasd_biodasdinfo() - fill out the dasd information structure
* @disk [in]: pointer to gendisk structure that references a DASD
* @info [out]: pointer to the dasd_information2_t structure
*
* Provide access to DASD specific information.
* The gendisk structure is checked if it belongs to the DASD driver by
* comparing the gendisk->fops pointer.
* If it does not belong to the DASD driver -EINVAL is returned.
* Otherwise the provided dasd_information2_t structure is filled out.
*
* Returns:
* %0 on success and a negative error value on failure.
*/
int dasd_biodasdinfo(struct gendisk *disk, struct dasd_information2_t *info)
{
struct dasd_device *base;
int error;
if (disk->fops != &dasd_device_operations)
return -EINVAL;
base = dasd_device_from_gendisk(disk);
if (!base)
return -ENODEV;
error = __dasd_ioctl_information(base->block, info);
dasd_put_device(base);
return error;
}
/* export that symbol_get in partition detection is possible */
EXPORT_SYMBOL_GPL(dasd_biodasdinfo);

9
include/linux/dasd_mod.h Normal file
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@ -0,0 +1,9 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef DASD_MOD_H
#define DASD_MOD_H
#include <asm/dasd.h>
extern int dasd_biodasdinfo(struct gendisk *disk, dasd_information2_t *info);
#endif