[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>

diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
index 4b010ff..7383781 100644 (file)
--- 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)