[PATCH 6/8] IB/qib: make qib_write_iter() deal with ITER_UBUF iov_iter

[Jens Axboe <axboe@kernel.dk>]

Don't assume that a user backed iterator is always of the type
ITER_IOVEC. Handle the single segment case separately, then we can
use the same logic for ITER_UBUF and ITER_IOVEC.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 drivers/infiniband/hw/qib/qib_file_ops.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/qib/qib_file_ops.c b/drivers/infiniband/hw/qib/qib_file_ops.c
index 80fe92a21f96..577d972ba048 100644
--- a/drivers/infiniband/hw/qib/qib_file_ops.c
+++ b/drivers/infiniband/hw/qib/qib_file_ops.c
@@ -2244,10 +2244,18 @@ static ssize_t qib_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	struct qib_filedata *fp = iocb->ki_filp->private_data;
 	struct qib_ctxtdata *rcd = ctxt_fp(iocb->ki_filp);
 	struct qib_user_sdma_queue *pq = fp->pq;
+	int nr_segs = iovec_nr_user_vecs(from);
 
-	if (!iter_is_iovec(from) || !from->nr_segs || !pq)
+	if (!from->user_backed)
+		return -EFAULT;
+	if (!nr_segs || !pq)
 		return -EINVAL;
 
+	if (nr_segs == 1) {
+		struct iovec iov = iov_iter_iovec(from);
+		return qib_user_sdma_writev(rcd, pq, &iov, 1);
+	}
+
 	return qib_user_sdma_writev(rcd, pq, from->iov, from->nr_segs);
 }
 
-- 
2.39.2