[PATCH v4 1/2] dasd: refactor dasd_ioctl_information

Stefan Haberland
2020-05-19T14:23:10Z

From: Christoph Hellwig <hch@lst.de>

Prepare for in-kernel callers of this functionality.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[sth@de.ibm.com: remove leftover kfree]
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
---
drivers/s390/block/dasd_ioctl.c | 42 ++++++++++++++++++---------------
1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index 9a5f3add325f..9b7782395c37 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -457,10 +457,9 @@ static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
/*
* Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
*/
-static int dasd_ioctl_information(struct dasd_block *block,
- unsigned int cmd, void __user *argp)
+static int __dasd_ioctl_information(struct dasd_block *block,
+ struct dasd_information2_t *dasd_info)
{
- struct dasd_information2_t *dasd_info;
struct subchannel_id sch_id;
struct ccw_dev_id dev_id;
struct dasd_device *base;
@@ -473,15 +472,9 @@ static int dasd_ioctl_information(struct dasd_block *block,
if (!base->discipline || !base->discipline->fill_info)
return -EINVAL;

- dasd_info = kzalloc(sizeof(struct dasd_information2_t), GFP_KERNEL);
- if (dasd_info == NULL)
- return -ENOMEM;
-
rc = base->discipline->fill_info(base, dasd_info);
- if (rc) {
- kfree(dasd_info);
+ if (rc)
return rc;
- }

cdev = base->cdev;
ccw_device_get_id(cdev, &dev_id);
@@ -520,15 +513,24 @@ static int dasd_ioctl_information(struct dasd_block *block,
list_for_each(l, &base->ccw_queue)
dasd_info->chanq_len++;
spin_unlock_irqrestore(&block->queue_lock, flags);
+ return 0;
+}

- rc = 0;
- if (copy_to_user(argp, dasd_info,
- ((cmd == (unsigned int) BIODASDINFO2) ?
- sizeof(struct dasd_information2_t) :
- sizeof(struct dasd_information_t))))
- rc = -EFAULT;
+static int dasd_ioctl_information(struct dasd_block *block, void __user *argp,
+ size_t copy_size)
+{
+ struct dasd_information2_t *dasd_info;
+ int error;
+
+ dasd_info = kzalloc(sizeof(*dasd_info), GFP_KERNEL);
+ if (!dasd_info)
+ return -ENOMEM;
+
+ error = __dasd_ioctl_information(block, dasd_info);
+ if (!error && copy_to_user(argp, dasd_info, copy_size))
+ error = -EFAULT;
kfree(dasd_info);
- return rc;
+ return error;
}

/*
@@ -622,10 +624,12 @@ int dasd_ioctl(struct block_device *bdev, fmode_t mode,
rc = dasd_ioctl_check_format(bdev, argp);
break;
case BIODASDINFO:
- rc = dasd_ioctl_information(block, cmd, argp);
+ rc = dasd_ioctl_information(block, argp,
+ sizeof(struct dasd_information_t));
break;
case BIODASDINFO2:
- rc = dasd_ioctl_information(block, cmd, argp);
+ rc = dasd_ioctl_information(block, argp,
+ sizeof(struct dasd_information2_t));
break;
case BIODASDPRRD:
rc = dasd_ioctl_read_profile(block, argp);
--
2.17.1