Merge tag 'for-6.3/iter-ubuf-2023-02-16' of git://git.kernel.dk/linux

Pull io_uring ITER_UBUF conversion from Jens Axboe:
 "Since we now have ITER_UBUF available, switch to using it for single
  ranges as it's more efficient than ITER_IOVEC for that"

* tag 'for-6.3/iter-ubuf-2023-02-16' of git://git.kernel.dk/linux:
  block: use iter_ubuf for single range
  iov_iter: move iter_ubuf check inside restore WARN
  io_uring: use iter_ubuf for single range imports
  io_uring: switch network send/recv to ITER_UBUF
  iov: add import_ubuf()

1 files changed, 13 insertions, 2 deletions

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index f9a3ff37ecd1..d9b3332c8405 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1877,6 +1877,17 @@ int import_single_range(int rw, void __user *buf, size_t len,
 }
 EXPORT_SYMBOL(import_single_range);
 
+int import_ubuf(int rw, void __user *buf, size_t len, struct iov_iter *i)
+{
+	if (len > MAX_RW_COUNT)
+		len = MAX_RW_COUNT;
+	if (unlikely(!access_ok(buf, len)))
+		return -EFAULT;
+
+	iov_iter_ubuf(i, rw, buf, len);
+	return 0;
+}
+
 /**
  * iov_iter_restore() - Restore a &struct iov_iter to the same state as when
  *     iov_iter_save_state() was called.
@@ -1891,8 +1902,8 @@ EXPORT_SYMBOL(import_single_range);
  */
 void iov_iter_restore(struct iov_iter *i, struct iov_iter_state *state)
 {
-	if (WARN_ON_ONCE(!iov_iter_is_bvec(i) && !iter_is_iovec(i)) &&
-			 !iov_iter_is_kvec(i) && !iter_is_ubuf(i))
+	if (WARN_ON_ONCE(!iov_iter_is_bvec(i) && !iter_is_iovec(i) &&
+			 !iter_is_ubuf(i)) && !iov_iter_is_kvec(i))
 		return;
 	i->iov_offset = state->iov_offset;
 	i->count = state->count;