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

Block patches

# gpg: Signature made Fri 15 Aug 2014 14:07:42 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (59 commits)
  block: Catch !bs->drv in bdrv_check()
  iotests: Add test for image header overlap
  qcow2: Catch !*host_offset for data allocation
  qcow2: Return useful error code in refcount_init()
  mirror: Handle failure for potentially large allocations
  vpc: Handle failure for potentially large allocations
  vmdk: Handle failure for potentially large allocations
  vhdx: Handle failure for potentially large allocations
  vdi: Handle failure for potentially large allocations
  rbd: Handle failure for potentially large allocations
  raw-win32: Handle failure for potentially large allocations
  raw-posix: Handle failure for potentially large allocations
  qed: Handle failure for potentially large allocations
  qcow2: Handle failure for potentially large allocations
  qcow1: Handle failure for potentially large allocations
  parallels: Handle failure for potentially large allocations
  nfs: Handle failure for potentially large allocations
  iscsi: Handle failure for potentially large allocations
  dmg: Handle failure for potentially large allocations
  curl: Handle failure for potentially large allocations
  ...

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

1 files changed, 14 insertions, 13 deletions

diff --git a/thread-pool.c b/thread-pool.c
index dfb699d..23888dc 100644
--- a/thread-pool.c
+++ b/thread-pool.c
@@ -21,7 +21,6 @@
 #include "block/coroutine.h"
 #include "trace.h"
 #include "block/block_int.h"
-#include "qemu/event_notifier.h"
 #include "block/thread-pool.h"
 #include "qemu/main-loop.h"
 
@@ -57,8 +56,8 @@ struct ThreadPoolElement {
 };
 
 struct ThreadPool {
-    EventNotifier notifier;
     AioContext *ctx;
+    QEMUBH *completion_bh;
     QemuMutex lock;
     QemuCond check_cancel;
     QemuCond worker_stopped;
@@ -119,7 +118,7 @@ static void *worker_thread(void *opaque)
             qemu_cond_broadcast(&pool->check_cancel);
         }
 
-        event_notifier_set(&pool->notifier);
+        qemu_bh_schedule(pool->completion_bh);
     }
 
     pool->cur_threads--;
@@ -168,12 +167,11 @@ static void spawn_thread(ThreadPool *pool)
     }
 }
 
-static void event_notifier_ready(EventNotifier *notifier)
+static void thread_pool_completion_bh(void *opaque)
 {
-    ThreadPool *pool = container_of(notifier, ThreadPool, notifier);
+    ThreadPool *pool = opaque;
     ThreadPoolElement *elem, *next;
 
-    event_notifier_test_and_clear(notifier);
 restart:
     QLIST_FOREACH_SAFE(elem, &pool->head, all, next) {
         if (elem->state != THREAD_CANCELED && elem->state != THREAD_DONE) {
@@ -187,6 +185,12 @@ restart:
             QLIST_REMOVE(elem, all);
             /* Read state before ret.  */
             smp_rmb();
+
+            /* Schedule ourselves in case elem->common.cb() calls aio_poll() to
+             * wait for another request that completed at the same time.
+             */
+            qemu_bh_schedule(pool->completion_bh);
+
             elem->common.cb(elem->common.opaque, elem->ret);
             qemu_aio_release(elem);
             goto restart;
@@ -215,7 +219,7 @@ static void thread_pool_cancel(BlockDriverAIOCB *acb)
         qemu_sem_timedwait(&pool->sem, 0) == 0) {
         QTAILQ_REMOVE(&pool->request_list, elem, reqs);
         elem->state = THREAD_CANCELED;
-        event_notifier_set(&pool->notifier);
+        qemu_bh_schedule(pool->completion_bh);
     } else {
         pool->pending_cancellations++;
         while (elem->state != THREAD_CANCELED && elem->state != THREAD_DONE) {
@@ -224,7 +228,7 @@ static void thread_pool_cancel(BlockDriverAIOCB *acb)
         pool->pending_cancellations--;
     }
     qemu_mutex_unlock(&pool->lock);
-    event_notifier_ready(&pool->notifier);
+    thread_pool_completion_bh(pool);
 }
 
 static const AIOCBInfo thread_pool_aiocb_info = {
@@ -293,8 +297,8 @@ static void thread_pool_init_one(ThreadPool *pool, AioContext *ctx)
     }
 
     memset(pool, 0, sizeof(*pool));
-    event_notifier_init(&pool->notifier, false);
     pool->ctx = ctx;
+    pool->completion_bh = aio_bh_new(ctx, thread_pool_completion_bh, pool);
     qemu_mutex_init(&pool->lock);
     qemu_cond_init(&pool->check_cancel);
     qemu_cond_init(&pool->worker_stopped);
@@ -304,8 +308,6 @@ static void thread_pool_init_one(ThreadPool *pool, AioContext *ctx)
 
     QLIST_INIT(&pool->head);
     QTAILQ_INIT(&pool->request_list);
-
-    aio_set_event_notifier(ctx, &pool->notifier, event_notifier_ready);
 }
 
 ThreadPool *thread_pool_new(AioContext *ctx)
@@ -339,11 +341,10 @@ void thread_pool_free(ThreadPool *pool)
 
     qemu_mutex_unlock(&pool->lock);
 
-    aio_set_event_notifier(pool->ctx, &pool->notifier, NULL);
+    qemu_bh_delete(pool->completion_bh);
     qemu_sem_destroy(&pool->sem);
     qemu_cond_destroy(&pool->check_cancel);
     qemu_cond_destroy(&pool->worker_stopped);
     qemu_mutex_destroy(&pool->lock);
-    event_notifier_cleanup(&pool->notifier);
     g_free(pool);
 }