1 files changed, 38 insertions, 20 deletions

diff --git a/dma-helpers.c b/dma-helpers.c
index 4610ea0420..86d2d0a997 100644
--- a/dma-helpers.c
+++ b/dma-helpers.c
@@ -42,7 +42,8 @@ typedef struct {
     BlockDriverAIOCB *acb;
     QEMUSGList *sg;
     uint64_t sector_num;
-    int is_write;
+    bool to_dev;
+    bool in_cancel;
     int sg_cur_index;
     target_phys_addr_t sg_cur_byte;
     QEMUIOVector iov;
@@ -58,7 +59,7 @@ static void reschedule_dma(void *opaque)
 
     qemu_bh_delete(dbs->bh);
     dbs->bh = NULL;
-    dma_bdrv_cb(opaque, 0);
+    dma_bdrv_cb(dbs, 0);
 }
 
 static void continue_after_map_failure(void *opaque)
@@ -75,9 +76,29 @@ static void dma_bdrv_unmap(DMAAIOCB *dbs)
 
     for (i = 0; i < dbs->iov.niov; ++i) {
         cpu_physical_memory_unmap(dbs->iov.iov[i].iov_base,
-                                  dbs->iov.iov[i].iov_len, !dbs->is_write,
+                                  dbs->iov.iov[i].iov_len, !dbs->to_dev,
                                   dbs->iov.iov[i].iov_len);
     }
+    qemu_iovec_reset(&dbs->iov);
+}
+
+static void dma_complete(DMAAIOCB *dbs, int ret)
+{
+    dma_bdrv_unmap(dbs);
+    if (dbs->common.cb) {
+        dbs->common.cb(dbs->common.opaque, ret);
+    }
+    qemu_iovec_destroy(&dbs->iov);
+    if (dbs->bh) {
+        qemu_bh_delete(dbs->bh);
+        dbs->bh = NULL;
+    }
+    if (!dbs->in_cancel) {
+        /* Requests may complete while dma_aio_cancel is in progress.  In
+         * this case, the AIOCB should not be released because it is still
+         * referenced by dma_aio_cancel.  */
+        qemu_aio_release(dbs);
+    }
 }
 
 static void dma_bdrv_cb(void *opaque, int ret)
@@ -89,19 +110,16 @@ static void dma_bdrv_cb(void *opaque, int ret)
     dbs->acb = NULL;
     dbs->sector_num += dbs->iov.size / 512;
     dma_bdrv_unmap(dbs);
-    qemu_iovec_reset(&dbs->iov);
 
     if (dbs->sg_cur_index == dbs->sg->nsg || ret < 0) {
-        dbs->common.cb(dbs->common.opaque, ret);
-        qemu_iovec_destroy(&dbs->iov);
-        qemu_aio_release(dbs);
+        dma_complete(dbs, ret);
         return;
     }
 
     while (dbs->sg_cur_index < dbs->sg->nsg) {
         cur_addr = dbs->sg->sg[dbs->sg_cur_index].base + dbs->sg_cur_byte;
         cur_len = dbs->sg->sg[dbs->sg_cur_index].len - dbs->sg_cur_byte;
-        mem = cpu_physical_memory_map(cur_addr, &cur_len, !dbs->is_write);
+        mem = cpu_physical_memory_map(cur_addr, &cur_len, !dbs->to_dev);
         if (!mem)
             break;
         qemu_iovec_add(&dbs->iov, mem, cur_len);
@@ -120,9 +138,7 @@ static void dma_bdrv_cb(void *opaque, int ret)
     dbs->acb = dbs->io_func(dbs->bs, dbs->sector_num, &dbs->iov,
                             dbs->iov.size / 512, dma_bdrv_cb, dbs);
     if (!dbs->acb) {
-        dma_bdrv_unmap(dbs);
-        qemu_iovec_destroy(&dbs->iov);
-        return;
+        dma_complete(dbs, -EIO);
     }
 }
 
@@ -131,8 +147,14 @@ static void dma_aio_cancel(BlockDriverAIOCB *acb)
     DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common);
 
     if (dbs->acb) {
-        bdrv_aio_cancel(dbs->acb);
+        BlockDriverAIOCB *acb = dbs->acb;
+        dbs->acb = NULL;
+        dbs->in_cancel = true;
+        bdrv_aio_cancel(acb);
+        dbs->in_cancel = false;
     }
+    dbs->common.cb = NULL;
+    dma_complete(dbs, 0);
 }
 
 static AIOPool dma_aio_pool = {
@@ -143,7 +165,7 @@ static AIOPool dma_aio_pool = {
 BlockDriverAIOCB *dma_bdrv_io(
     BlockDriverState *bs, QEMUSGList *sg, uint64_t sector_num,
     DMAIOFunc *io_func, BlockDriverCompletionFunc *cb,
-    void *opaque, int is_write)
+    void *opaque, bool to_dev)
 {
     DMAAIOCB *dbs = qemu_aio_get(&dma_aio_pool, bs, cb, opaque);
 
@@ -153,15 +175,11 @@ BlockDriverAIOCB *dma_bdrv_io(
     dbs->sector_num = sector_num;
     dbs->sg_cur_index = 0;
     dbs->sg_cur_byte = 0;
-    dbs->is_write = is_write;
+    dbs->to_dev = to_dev;
     dbs->io_func = io_func;
     dbs->bh = NULL;
     qemu_iovec_init(&dbs->iov, sg->nsg);
     dma_bdrv_cb(dbs, 0);
-    if (!dbs->acb) {
-        qemu_aio_release(dbs);
-        return NULL;
-    }
     return &dbs->common;
 }
 
@@ -170,12 +188,12 @@ BlockDriverAIOCB *dma_bdrv_read(BlockDriverState *bs,
                                 QEMUSGList *sg, uint64_t sector,
                                 void (*cb)(void *opaque, int ret), void *opaque)
 {
-    return dma_bdrv_io(bs, sg, sector, bdrv_aio_readv, cb, opaque, 0);
+    return dma_bdrv_io(bs, sg, sector, bdrv_aio_readv, cb, opaque, false);
 }
 
 BlockDriverAIOCB *dma_bdrv_write(BlockDriverState *bs,
                                  QEMUSGList *sg, uint64_t sector,
                                  void (*cb)(void *opaque, int ret), void *opaque)
 {
-    return dma_bdrv_io(bs, sg, sector, bdrv_aio_writev, cb, opaque, 1);
+    return dma_bdrv_io(bs, sg, sector, bdrv_aio_writev, cb, opaque, true);
 }