[S390] s390: use simple_read_from_buffer()

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 10 insertions, 19 deletions

diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
index 4b010ff814c9..7383781f3e6a 100644
--- a/arch/s390/hypfs/inode.c
+++ b/arch/s390/hypfs/inode.c
@@ -150,33 +150,24 @@ static ssize_t hypfs_aio_read(struct kiocb *iocb, const struct iovec *iov,
                               unsigned long nr_segs, loff_t offset)
 {
         char *data;
-        size_t len;
+        ssize_t ret;
         struct file *filp = iocb->ki_filp;
         /* XXX: temporary */
         char __user *buf = iov[0].iov_base;
         size_t count = iov[0].iov_len;
 
-        if (nr_segs != 1) {
-                count = -EINVAL;
-                goto out;
-        }
+        if (nr_segs != 1)
+                return -EINVAL;
 
         data = filp->private_data;
-        len = strlen(data);
-        if (offset > len) {
-                count = 0;
-                goto out;
-        }
-        if (count > len - offset)
-                count = len - offset;
-        if (copy_to_user(buf, data + offset, count)) {
-                count = -EFAULT;
-                goto out;
-        }
-        iocb->ki_pos += count;
+        ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data));
+        if (ret <= 0)
+                return ret;
+
+        iocb->ki_pos += ret;
         file_accessed(filp);
-out:
-        return count;
+
+        return ret;
 }
 static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov,
                               unsigned long nr_segs, loff_t offset)