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>

4 files changed, 39 insertions, 79 deletions

diff --git a/util/Makefile.objs b/util/Makefile.objs
index 36c7dcc..ad0f9c7 100644
--- a/util/Makefile.objs
+++ b/util/Makefile.objs
@@ -25,7 +25,6 @@ util-obj-y += uuid.o
 util-obj-y += throttle.o
 util-obj-y += getauxval.o
 util-obj-y += readline.o
-util-obj-y += rfifolock.o
 util-obj-y += rcu.o
 util-obj-y += qemu-coroutine.o qemu-coroutine-lock.o qemu-coroutine-io.o
 util-obj-y += qemu-coroutine-sleep.o
diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
index ce51b37..d20cdde 100644
--- a/util/qemu-thread-posix.c
+++ b/util/qemu-thread-posix.c
@@ -80,6 +80,20 @@ void qemu_mutex_unlock(QemuMutex *mutex)
         error_exit(err, __func__);
 }
 
+void qemu_rec_mutex_init(QemuRecMutex *mutex)
+{
+    int err;
+    pthread_mutexattr_t attr;
+
+    pthread_mutexattr_init(&attr);
+    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+    err = pthread_mutex_init(&mutex->lock, &attr);
+    pthread_mutexattr_destroy(&attr);
+    if (err) {
+        error_exit(err, __func__);
+    }
+}
+
 void qemu_cond_init(QemuCond *cond)
 {
     int err;
diff --git a/util/qemu-thread-win32.c b/util/qemu-thread-win32.c
index 072806f..728e76b 100644
--- a/util/qemu-thread-win32.c
+++ b/util/qemu-thread-win32.c
@@ -79,6 +79,31 @@ void qemu_mutex_unlock(QemuMutex *mutex)
     LeaveCriticalSection(&mutex->lock);
 }
 
+void qemu_rec_mutex_init(QemuRecMutex *mutex)
+{
+    InitializeCriticalSection(&mutex->lock);
+}
+
+void qemu_rec_mutex_destroy(QemuRecMutex *mutex)
+{
+    DeleteCriticalSection(&mutex->lock);
+}
+
+void qemu_rec_mutex_lock(QemuRecMutex *mutex)
+{
+    EnterCriticalSection(&mutex->lock);
+}
+
+int qemu_rec_mutex_trylock(QemuRecMutex *mutex)
+{
+    return !TryEnterCriticalSection(&mutex->lock);
+}
+
+void qemu_rec_mutex_unlock(QemuRecMutex *mutex)
+{
+    LeaveCriticalSection(&mutex->lock);
+}
+
 void qemu_cond_init(QemuCond *cond)
 {
     memset(cond, 0, sizeof(*cond));
diff --git a/util/rfifolock.c b/util/rfifolock.c
deleted file mode 100644
index 084c2f0..0000000
--- a/util/rfifolock.c
+++ /dev/null
@@ -1,78 +0,0 @@
-/*
- * Recursive FIFO lock
- *
- * Copyright Red Hat, Inc. 2013
- *
- * Authors:
- *  Stefan Hajnoczi   <stefanha@redhat.com>
- *
- * This work is licensed under the terms of the GNU LGPL, version 2 or later.
- * See the COPYING.LIB file in the top-level directory.
- *
- */
-
-#include "qemu/osdep.h"
-#include "qemu/rfifolock.h"
-
-void rfifolock_init(RFifoLock *r, void (*cb)(void *), void *opaque)
-{
-    qemu_mutex_init(&r->lock);
-    r->head = 0;
-    r->tail = 0;
-    qemu_cond_init(&r->cond);
-    r->nesting = 0;
-    r->cb = cb;
-    r->cb_opaque = opaque;
-}
-
-void rfifolock_destroy(RFifoLock *r)
-{
-    qemu_cond_destroy(&r->cond);
-    qemu_mutex_destroy(&r->lock);
-}
-
-/*
- * Theory of operation:
- *
- * In order to ensure FIFO ordering, implement a ticketlock.  Threads acquiring
- * the lock enqueue themselves by incrementing the tail index.  When the lock
- * is unlocked, the head is incremented and waiting threads are notified.
- *
- * Recursive locking does not take a ticket since the head is only incremented
- * when the outermost recursive caller unlocks.
- */
-void rfifolock_lock(RFifoLock *r)
-{
-    qemu_mutex_lock(&r->lock);
-
-    /* Take a ticket */
-    unsigned int ticket = r->tail++;
-
-    if (r->nesting > 0 && qemu_thread_is_self(&r->owner_thread)) {
-        r->tail--; /* put ticket back, we're nesting */
-    } else {
-        while (ticket != r->head) {
-            /* Invoke optional contention callback */
-            if (r->cb) {
-                r->cb(r->cb_opaque);
-            }
-            qemu_cond_wait(&r->cond, &r->lock);
-        }
-        qemu_thread_get_self(&r->owner_thread);
-    }
-
-    r->nesting++;
-    qemu_mutex_unlock(&r->lock);
-}
-
-void rfifolock_unlock(RFifoLock *r)
-{
-    qemu_mutex_lock(&r->lock);
-    assert(r->nesting > 0);
-    assert(qemu_thread_is_self(&r->owner_thread));
-    if (--r->nesting == 0) {
-        r->head++;
-        qemu_cond_broadcast(&r->cond);
-    }
-    qemu_mutex_unlock(&r->lock);
-}