block: explicitly acquire aiocontext in callbacks that need it

[qemu.git] / block / io.c

diff --git a/block/io.c b/block/io.c
index 4f005623f71e95a4f7d27b1767ef2ae04279350e..dd6c74f62ce3d6705ab72f94c703d1061ab60a09 100644 (file)
--- a/block/io.c
+++ b/block/io.c
@@ -228,9 +228,7 @@ void bdrv_drained_begin(BlockDriverState *bs)
         bdrv_parent_drained_begin(bs);
     }
 
-    bdrv_io_unplugged_begin(bs);
     bdrv_drain_recurse(bs);
-    bdrv_io_unplugged_end(bs);
 }
 
 void bdrv_drained_end(BlockDriverState *bs)
@@ -302,7 +300,6 @@ void bdrv_drain_all_begin(void)
 
         aio_context_acquire(aio_context);
         bdrv_parent_drained_begin(bs);
-        bdrv_io_unplugged_begin(bs);
         aio_disable_external(aio_context);
         aio_context_release(aio_context);
 
@@ -347,7 +344,6 @@ void bdrv_drain_all_end(void)
 
         aio_context_acquire(aio_context);
         aio_enable_external(aio_context);
-        bdrv_io_unplugged_end(bs);
         bdrv_parent_drained_end(bs);
         aio_context_release(aio_context);
     }
@@ -2084,6 +2080,11 @@ void bdrv_aio_cancel(BlockAIOCB *acb)
         if (acb->aiocb_info->get_aio_context) {
             aio_poll(acb->aiocb_info->get_aio_context(acb), true);
         } else if (acb->bs) {
+            /* qemu_aio_ref and qemu_aio_unref are not thread-safe, so
+             * assert that we're not using an I/O thread.  Thread-safe
+             * code should use bdrv_aio_cancel_async exclusively.
+             */
+            assert(bdrv_get_aio_context(acb->bs) == qemu_get_aio_context());
             aio_poll(bdrv_get_aio_context(acb->bs), true);
         } else {
             abort();
@@ -2243,35 +2244,6 @@ BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
     return &acb->common;
 }
 
-void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs,
-                   BlockCompletionFunc *cb, void *opaque)
-{
-    BlockAIOCB *acb;
-
-    acb = g_malloc(aiocb_info->aiocb_size);
-    acb->aiocb_info = aiocb_info;
-    acb->bs = bs;
-    acb->cb = cb;
-    acb->opaque = opaque;
-    acb->refcnt = 1;
-    return acb;
-}
-
-void qemu_aio_ref(void *p)
-{
-    BlockAIOCB *acb = p;
-    acb->refcnt++;
-}
-
-void qemu_aio_unref(void *p)
-{
-    BlockAIOCB *acb = p;
-    assert(acb->refcnt > 0);
-    if (--acb->refcnt == 0) {
-        g_free(acb);
-    }
-}
-
 /**************************************************************/
 /* Coroutine block device emulation */
 
@@ -2650,7 +2622,7 @@ void bdrv_io_plug(BlockDriverState *bs)
         bdrv_io_plug(child->bs);
     }
 
-    if (bs->io_plugged++ == 0 && bs->io_plug_disabled == 0) {
+    if (bs->io_plugged++ == 0) {
         BlockDriver *drv = bs->drv;
         if (drv && drv->bdrv_io_plug) {
             drv->bdrv_io_plug(bs);
@@ -2663,7 +2635,7 @@ void bdrv_io_unplug(BlockDriverState *bs)
     BdrvChild *child;
 
     assert(bs->io_plugged);
-    if (--bs->io_plugged == 0 && bs->io_plug_disabled == 0) {
+    if (--bs->io_plugged == 0) {
         BlockDriver *drv = bs->drv;
         if (drv && drv->bdrv_io_unplug) {
             drv->bdrv_io_unplug(bs);
@@ -2674,36 +2646,3 @@ void bdrv_io_unplug(BlockDriverState *bs)
         bdrv_io_unplug(child->bs);
     }
 }
-
-void bdrv_io_unplugged_begin(BlockDriverState *bs)
-{
-    BdrvChild *child;
-
-    if (bs->io_plug_disabled++ == 0 && bs->io_plugged > 0) {
-        BlockDriver *drv = bs->drv;
-        if (drv && drv->bdrv_io_unplug) {
-            drv->bdrv_io_unplug(bs);
-        }
-    }
-
-    QLIST_FOREACH(child, &bs->children, next) {
-        bdrv_io_unplugged_begin(child->bs);
-    }
-}
-
-void bdrv_io_unplugged_end(BlockDriverState *bs)
-{
-    BdrvChild *child;
-
-    assert(bs->io_plug_disabled);
-    QLIST_FOREACH(child, &bs->children, next) {
-        bdrv_io_unplugged_end(child->bs);
-    }
-
-    if (--bs->io_plug_disabled == 0 && bs->io_plugged > 0) {
-        BlockDriver *drv = bs->drv;
-        if (drv && drv->bdrv_io_plug) {
-            drv->bdrv_io_plug(bs);
-        }
-    }
-}