[PATCH v3 1/3] dasd: refactor dasd_ioctl_information

[Stefan Haberland]

From: Christoph Hellwig <h...@lst.de>

Prepare for in-kernel callers of this functionality.

Signed-off-by: Christoph Hellwig <h...@lst.de>
Signed-off-by: Stefan Haberland <s...@linux.ibm.com>
---
 drivers/s390/block/dasd_ioctl.c | 38 +++++++++++++++++++--------------
 1 file changed, 22 insertions(+), 16 deletions(-)

diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index 9a5f3add325f..dabcb4ce92da 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;
@@ -473,10 +472,6 @@ 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);
@@ -520,15 +515,24 @@ 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 = 0;
+
+       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 +626,12 @@ 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