io_uring: add flag for disabling provided buffer recycling

commit 8a3e8ee56417f5e0e66580d93941ed9d6f4c8274 upstream.

If we need to continue doing this IO, then we don't want a potentially
selected buffer recycled. Add a flag for that.

Set this for recv/recvmsg if they do partial IO.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 04441e9..2350d43 100644 (file)
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -740,6 +740,7 @@ enum {
        REQ_F_CREDS_BIT,
        REQ_F_REFCOUNT_BIT,
        REQ_F_ARM_LTIMEOUT_BIT,
+       REQ_F_PARTIAL_IO_BIT,
        /* keep async read/write and isreg together and in order */
        REQ_F_NOWAIT_READ_BIT,
        REQ_F_NOWAIT_WRITE_BIT,
@@ -795,6 +796,8 @@ enum {
        REQ_F_REFCOUNT          = BIT(REQ_F_REFCOUNT_BIT),
        /* there is a linked timeout that has to be armed */
        REQ_F_ARM_LTIMEOUT      = BIT(REQ_F_ARM_LTIMEOUT_BIT),
+       /* request has already done partial IO */
+       REQ_F_PARTIAL_IO        = BIT(REQ_F_PARTIAL_IO_BIT),
 };
 
 struct async_poll {
@@ -5123,6 +5126,7 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
                        ret = -EINTR;
                if (ret > 0 && io_net_retry(sock, flags)) {
                        sr->done_io += ret;
+                       req->flags |= REQ_F_PARTIAL_IO;
                        return io_setup_async_msg(req, kmsg);
                }
                req_set_fail(req);
@@ -5196,6 +5200,7 @@ out_free:
                        sr->len -= ret;
                        sr->buf += ret;
                        sr->done_io += ret;
+                       req->flags |= REQ_F_PARTIAL_IO;
                        return -EAGAIN;
                }
                req_set_fail(req);