io_uring/rw: simplify io_rw_recycle()

Instead of freeing iovecs in case of IO_URING_F_UNLOCKED in
io_rw_recycle(), leave it be and rely on the core io_uring code to
call io_readv_writev_cleanup() later. This way the iovec will get
recycled and we can clean up io_rw_recycle() and kill
io_rw_iovec_free().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/14f83b112eb40078bea18e15d77a4f99fc981a44.1738087204.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: isilence

io_uring/rw.c

@@ -146,23 +146,13 @@ static inline int io_import_iovec(int rw, struct io_kiocb *req,
 	return 0;
 }
 
-static void io_rw_iovec_free(struct io_async_rw *rw)
-{
-	if (rw->free_iovec) {
-		kfree(rw->free_iovec);
-		rw->free_iov_nr = 0;
-		rw->free_iovec = NULL;
-	}
-}
-
 static void io_rw_recycle(struct io_kiocb *req, unsigned int issue_flags)
 {
 	struct io_async_rw *rw = req->async_data;
 
-	if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) {
-		io_rw_iovec_free(rw);
+	if (unlikely(issue_flags & IO_URING_F_UNLOCKED))
 		return;
-	}
+
 	io_alloc_cache_kasan(&rw->free_iovec, &rw->free_iov_nr);
 	if (io_alloc_cache_put(&req->ctx->rw_cache, rw)) {
 		req->async_data = NULL;
@@ -1310,6 +1300,6 @@ void io_rw_cache_free(const void *entry)
 	struct io_async_rw *rw = (struct io_async_rw *) entry;
 
 	if (rw->free_iovec)
-		io_rw_iovec_free(rw);
+		kfree(rw->free_iovec);
 	kfree(rw);
 }