[PATCH 077/437] relay: convert to read/write iterators

[Jens Axboe]

Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
 kernel/relay.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/kernel/relay.c b/kernel/relay.c
index a8e90e98bf2c..d34f5b0e4e53 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1030,12 +1030,10 @@ static size_t relay_file_read_end_pos(struct rchan_buf *buf,
 	return end_pos;
 }
 
-static ssize_t relay_file_read(struct file *filp,
-			       char __user *buffer,
-			       size_t count,
-			       loff_t *ppos)
+static ssize_t relay_file_read(struct kiocb *iocb, struct iov_iter *to)
 {
-	struct rchan_buf *buf = filp->private_data;
+	struct rchan_buf *buf = iocb->ki_filp->private_data;
+	size_t count = iov_iter_count(to);
 	size_t read_start, avail;
 	size_t written = 0;
 	int ret;
@@ -1043,7 +1041,7 @@ static ssize_t relay_file_read(struct file *filp,
 	if (!count)
 		return 0;
 
-	inode_lock(file_inode(filp));
+	inode_lock(file_inode(iocb->ki_filp));
 	do {
 		void *from;
 
@@ -1058,27 +1056,25 @@ static ssize_t relay_file_read(struct file *filp,
 		avail = min(count, avail);
 		from = buf->start + read_start;
 		ret = avail;
-		if (copy_to_user(buffer, from, avail))
+		if (!copy_to_iter_full(from, avail, to))
 			break;
 
-		buffer += ret;
 		written += ret;
 		count -= ret;
 
 		relay_file_read_consume(buf, read_start, ret);
-		*ppos = relay_file_read_end_pos(buf, read_start, ret);
+		iocb->ki_pos = relay_file_read_end_pos(buf, read_start, ret);
 	} while (count);
-	inode_unlock(file_inode(filp));
+	inode_unlock(file_inode(iocb->ki_filp));
 
 	return written;
 }
 
-
 const struct file_operations relay_file_operations = {
 	.open		= relay_file_open,
 	.poll		= relay_file_poll,
 	.mmap		= relay_file_mmap,
-	.read		= relay_file_read,
+	.read_iter	= relay_file_read,
 	.llseek		= no_llseek,
 	.release	= relay_file_release,
 };
-- 
2.43.0