hw/9pfs: Update v9fs_readlink to use coroutine

[qemu.git] / linux-aio.c

diff --git a/linux-aio.c b/linux-aio.c
index 19ad36d7498dbb256d6ab602be152703bf1a2af7..dc3faf24995a673c802ea754a28b73c26d69134c 100644 (file)
--- a/linux-aio.c
+++ b/linux-aio.c
@@ -31,6 +31,7 @@ struct qemu_laiocb {
     struct iocb iocb;
     ssize_t ret;
     size_t nbytes;
+    QLIST_ENTRY(qemu_laiocb) node;
 };
 
 struct qemu_laio_state {
@@ -44,6 +45,38 @@ static inline ssize_t io_event_ret(struct io_event *ev)
     return (ssize_t)(((uint64_t)ev->res2 << 32) | ev->res);
 }
 
+/*
+ * Completes an AIO request (calls the callback and frees the ACB).
+ */
+static void qemu_laio_process_completion(struct qemu_laio_state *s,
+    struct qemu_laiocb *laiocb)
+{
+    int ret;
+
+    s->count--;
+
+    ret = laiocb->ret;
+    if (ret != -ECANCELED) {
+        if (ret == laiocb->nbytes)
+            ret = 0;
+        else if (ret >= 0)
+            ret = -EINVAL;
+
+        laiocb->common.cb(laiocb->common.opaque, ret);
+    }
+
+    qemu_aio_release(laiocb);
+}
+
+/*
+ * All requests are directly processed when they complete, so there's nothing
+ * left to do during qemu_aio_wait().
+ */
+static int qemu_laio_process_requests(void *opaque)
+{
+    return 0;
+}
+
 static void qemu_laio_completion_cb(void *opaque)
 {
     struct qemu_laio_state *s = opaque;
@@ -57,7 +90,7 @@ static void qemu_laio_completion_cb(void *opaque)
 
         do {
             ret = read(s->efd, &val, sizeof(val));
-        } while (ret == 1 && errno == EINTR);
+        } while (ret == -1 && errno == EINTR);
 
         if (ret == -1 && errno == EAGAIN)
             break;
@@ -74,19 +107,8 @@ static void qemu_laio_completion_cb(void *opaque)
             struct qemu_laiocb *laiocb =
                     container_of(iocb, struct qemu_laiocb, iocb);
 
-            s->count--;
-
-            ret = laiocb->ret = io_event_ret(&events[i]);
-            if (ret != -ECANCELED) {
-                if (ret == laiocb->nbytes)
-                    ret = 0;
-                else if (ret >= 0)
-                    ret = -EINVAL;
-
-                laiocb->common.cb(laiocb->common.opaque, ret);
-            }
-
-            qemu_aio_release(laiocb);
+            laiocb->ret = io_event_ret(&events[i]);
+            qemu_laio_process_completion(s, laiocb);
         }
     }
 }
@@ -191,8 +213,8 @@ void *laio_init(void)
     if (io_setup(MAX_EVENTS, &s->ctx) != 0)
         goto out_close_efd;
 
-    qemu_aio_set_fd_handler(s->efd, qemu_laio_completion_cb,
-                            NULL, qemu_laio_flush_cb, NULL, s);
+    qemu_aio_set_fd_handler(s->efd, qemu_laio_completion_cb, NULL,
+        qemu_laio_flush_cb, qemu_laio_process_requests, s);
 
     return s;