io_uring/net: improve zc addr import error handling

We may account memory to a memcg of a request that didn't even got to
the network layer. It's not a bug as it'll be routinely cleaned up on
flush, but it might be confusing for the userspace.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b8aae61f4c3ddc4da97c1da876bb73871f352d50.1660566179.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/net.c b/io_uring/net.c
index 2129562..f7cbd71 100644 (file)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -977,6 +977,14 @@ int io_sendzc(struct io_kiocb *req, unsigned int issue_flags)
        msg.msg_controllen = 0;
        msg.msg_namelen = 0;
 
+       if (zc->addr) {
+               ret = move_addr_to_kernel(zc->addr, zc->addr_len, &address);
+               if (unlikely(ret < 0))
+                       return ret;
+               msg.msg_name = (struct sockaddr *)&address;
+               msg.msg_namelen = zc->addr_len;
+       }
+
        if (zc->flags & IORING_RECVSEND_FIXED_BUF) {
                ret = io_import_fixed(WRITE, &msg.msg_iter, req->imu,
                                        (u64)(uintptr_t)zc->buf, zc->len);
@@ -992,14 +1000,6 @@ int io_sendzc(struct io_kiocb *req, unsigned int issue_flags)
                        return ret;
        }
 
-       if (zc->addr) {
-               ret = move_addr_to_kernel(zc->addr, zc->addr_len, &address);
-               if (unlikely(ret < 0))
-                       return ret;
-               msg.msg_name = (struct sockaddr *)&address;
-               msg.msg_namelen = zc->addr_len;
-       }
-
        msg_flags = zc->msg_flags | MSG_ZEROCOPY;
        if (issue_flags & IO_URING_F_NONBLOCK)
                msg_flags |= MSG_DONTWAIT;