Merge remote-tracking branch 'remotes/famz/tags/for-upstream' into staging

# gpg: Signature made Fri 28 Oct 2016 15:47:39 BST
# gpg:                using RSA key 0xCA35624C6A9171C6
# gpg: Good signature from "Fam Zheng <famz@redhat.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 5003 7CB7 9706 0F76 F021  AD56 CA35 624C 6A91 71C6

* remotes/famz/tags/for-upstream:
  aio: convert from RFifoLock to QemuRecMutex
  qemu-thread: introduce QemuRecMutex
  iothread: release AioContext around aio_poll
  block: only call aio_poll on the current thread's AioContext
  qemu-img: call aio_context_acquire/release around block job
  qemu-io: acquire AioContext
  block: prepare bdrv_reopen_multiple to release AioContext
  replication: pass BlockDriverState to reopen_backing_file
  iothread: detach all block devices before stopping them
  aio: introduce qemu_get_current_aio_context
  sheepdog: use BDRV_POLL_WHILE
  nfs: use BDRV_POLL_WHILE
  nfs: move nfs_set_events out of the while loops
  block: introduce BDRV_POLL_WHILE
  qed: Implement .bdrv_drain
  block: change drain to look only at one child at a time
  block: add BDS field to count in-flight requests
  mirror: use bdrv_drained_begin/bdrv_drained_end
  blockjob: introduce .drain callback for jobs
  replication: interrupt failover if the main device is closed

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 7 insertions, 22 deletions

diff --git a/async.c b/async.c
index f30d011ebc..b2de360c23 100644
--- a/async.c
+++ b/async.c
@@ -61,6 +61,7 @@ void aio_bh_schedule_oneshot(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
     smp_wmb();
     ctx->first_bh = bh;
     qemu_mutex_unlock(&ctx->bh_lock);
+    aio_notify(ctx);
 }
 
 QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
@@ -106,8 +107,8 @@ int aio_bh_poll(AioContext *ctx)
          * aio_notify again if necessary.
          */
         if (atomic_xchg(&bh->scheduled, 0)) {
-            /* Idle BHs and the notify BH don't count as progress */
-            if (!bh->idle && bh != ctx->notify_dummy_bh) {
+            /* Idle BHs don't count as progress */
+            if (!bh->idle) {
                 ret = 1;
             }
             bh->idle = 0;
@@ -259,7 +260,6 @@ aio_ctx_finalize(GSource     *source)
 {
     AioContext *ctx = (AioContext *) source;
 
-    qemu_bh_delete(ctx->notify_dummy_bh);
     thread_pool_free(ctx->thread_pool);
 
 #ifdef CONFIG_LINUX_AIO
@@ -284,7 +284,7 @@ aio_ctx_finalize(GSource     *source)
 
     aio_set_event_notifier(ctx, &ctx->notifier, false, NULL);
     event_notifier_cleanup(&ctx->notifier);
-    rfifolock_destroy(&ctx->lock);
+    qemu_rec_mutex_destroy(&ctx->lock);
     qemu_mutex_destroy(&ctx->bh_lock);
     timerlistgroup_deinit(&ctx->tlg);
 }
@@ -345,19 +345,6 @@ static void aio_timerlist_notify(void *opaque)
     aio_notify(opaque);
 }
 
-static void aio_rfifolock_cb(void *opaque)
-{
-    AioContext *ctx = opaque;
-
-    /* Kick owner thread in case they are blocked in aio_poll() */
-    qemu_bh_schedule(ctx->notify_dummy_bh);
-}
-
-static void notify_dummy_bh(void *opaque)
-{
-    /* Do nothing, we were invoked just to force the event loop to iterate */
-}
-
 static void event_notifier_dummy_cb(EventNotifier *e)
 {
 }
@@ -385,11 +372,9 @@ AioContext *aio_context_new(Error **errp)
 #endif
     ctx->thread_pool = NULL;
     qemu_mutex_init(&ctx->bh_lock);
-    rfifolock_init(&ctx->lock, aio_rfifolock_cb, ctx);
+    qemu_rec_mutex_init(&ctx->lock);
     timerlistgroup_init(&ctx->tlg, aio_timerlist_notify, ctx);
 
-    ctx->notify_dummy_bh = aio_bh_new(ctx, notify_dummy_bh, NULL);
-
     return ctx;
 fail:
     g_source_destroy(&ctx->source);
@@ -408,10 +393,10 @@ void aio_context_unref(AioContext *ctx)
 
 void aio_context_acquire(AioContext *ctx)
 {
-    rfifolock_lock(&ctx->lock);
+    qemu_rec_mutex_lock(&ctx->lock);
 }
 
 void aio_context_release(AioContext *ctx)
 {
-    rfifolock_unlock(&ctx->lock);
+    qemu_rec_mutex_unlock(&ctx->lock);
 }