Revert "vl: Fix to create migration object before block backends again"

[mirror_qemu.git] / block / linux-aio.c

diff --git a/block/linux-aio.c b/block/linux-aio.c
index d4e19d444cf4030fa9ae99f78e70b85c8c278984..d4b61fb2517d6b9fb6ff088d37180e3f4fb8792d 100644 (file)
--- a/block/linux-aio.c
+++ b/block/linux-aio.c
@@ -15,6 +15,7 @@
 #include "block/raw-aio.h"
 #include "qemu/event_notifier.h"
 #include "qemu/coroutine.h"
+#include "qapi/error.h"
 
 #include <libaio.h>
 
@@ -54,10 +55,10 @@ struct LinuxAioState {
     io_context_t ctx;
     EventNotifier e;
 
-    /* io queue for submit at batch */
+    /* io queue for submit at batch.  Protected by AioContext lock. */
     LaioQueue io_q;
 
-    /* I/O completion processing */
+    /* I/O completion processing.  Only runs in I/O thread.  */
     QEMUBH *completion_bh;
     int event_idx;
     int event_max;
@@ -94,10 +95,13 @@ static void qemu_laio_process_completion(struct qemu_laiocb *laiocb)
 
     laiocb->ret = ret;
     if (laiocb->co) {
-        /* Jump and continue completion for foreign requests, don't do
-         * anything for current request, it will be completed shortly. */
-        if (laiocb->co != qemu_coroutine_self()) {
-            qemu_coroutine_enter(laiocb->co);
+        /* If the coroutine is already entered it must be in ioq_submit() and
+         * will notice laio->ret has been filled in when it eventually runs
+         * later.  Coroutines cannot be entered recursively so avoid doing
+         * that!
+         */
+        if (!qemu_coroutine_entered(laiocb->co)) {
+            aio_co_wake(laiocb->co);
         }
     } else {
         laiocb->common.cb(laiocb->common.opaque, ret);
@@ -230,10 +234,13 @@ static void qemu_laio_process_completions(LinuxAioState *s)
 
 static void qemu_laio_process_completions_and_submit(LinuxAioState *s)
 {
+    aio_context_acquire(s->aio_context);
     qemu_laio_process_completions(s);
+
     if (!s->io_q.plugged && !QSIMPLEQ_EMPTY(&s->io_q.pending)) {
         ioq_submit(s);
     }
+    aio_context_release(s->aio_context);
 }
 
 static void qemu_laio_completion_bh(void *opaque)
@@ -252,6 +259,20 @@ static void qemu_laio_completion_cb(EventNotifier *e)
     }
 }
 
+static bool qemu_laio_poll_cb(void *opaque)
+{
+    EventNotifier *e = opaque;
+    LinuxAioState *s = container_of(e, LinuxAioState, e);
+    struct io_event *events;
+
+    if (!io_getevents_peek(s->ctx, &events)) {
+        return false;
+    }
+
+    qemu_laio_process_completions_and_submit(s);
+    return true;
+}
+
 static void laio_cancel(BlockAIOCB *blockacb)
 {
     struct qemu_laiocb *laiocb = (struct qemu_laiocb *)blockacb;
@@ -363,10 +384,10 @@ static int laio_do_submit(int fd, struct qemu_laiocb *laiocb, off_t offset,
     switch (type) {
     case QEMU_AIO_WRITE:
         io_prep_pwritev(iocbs, fd, qiov->iov, qiov->niov, offset);
-       break;
+        break;
     case QEMU_AIO_READ:
         io_prep_preadv(iocbs, fd, qiov->iov, qiov->niov, offset);
-       break;
+        break;
     /* Currently Linux kernel does not support other operations */
     default:
         fprintf(stderr, "%s: invalid AIO request type 0x%x.\n",
@@ -436,8 +457,9 @@ BlockAIOCB *laio_submit(BlockDriverState *bs, LinuxAioState *s, int fd,
 
 void laio_detach_aio_context(LinuxAioState *s, AioContext *old_context)
 {
-    aio_set_event_notifier(old_context, &s->e, false, NULL);
+    aio_set_event_notifier(old_context, &s->e, false, NULL, NULL);
     qemu_bh_delete(s->completion_bh);
+    s->aio_context = NULL;
 }
 
 void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context)
@@ -445,19 +467,25 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context)
     s->aio_context = new_context;
     s->completion_bh = aio_bh_new(new_context, qemu_laio_completion_bh, s);
     aio_set_event_notifier(new_context, &s->e, false,
-                           qemu_laio_completion_cb);
+                           qemu_laio_completion_cb,
+                           qemu_laio_poll_cb);
 }
 
-LinuxAioState *laio_init(void)
+LinuxAioState *laio_init(Error **errp)
 {
+    int rc;
     LinuxAioState *s;
 
     s = g_malloc0(sizeof(*s));
-    if (event_notifier_init(&s->e, false) < 0) {
+    rc = event_notifier_init(&s->e, false);
+    if (rc < 0) {
+        error_setg_errno(errp, -rc, "failed to to initialize event notifier");
         goto out_free_state;
     }
 
-    if (io_setup(MAX_EVENTS, &s->ctx) != 0) {
+    rc = io_setup(MAX_EVENTS, &s->ctx);
+    if (rc < 0) {
+        error_setg_errno(errp, -rc, "failed to create linux AIO context");
         goto out_close_efd;
     }