[Qemu-devel] [PATCH] fixup! block-migration: acquire AioContext as necessary

[Paolo Bonzini <pbonzini@redhat.com>]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 migration/block.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/migration/block.c b/migration/block.c
index 3bfa908..eea4788 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -54,6 +54,7 @@ typedef struct BlkMigDevState {
     int shared_base;
     int64_t total_sectors;
     QSIMPLEQ_ENTRY(BlkMigDevState) entry;
+    Error *blocker;
 
     /* Only used by migration thread.  Does not need a lock.  */
     int bulk_completed;
@@ -68,9 +69,10 @@ typedef struct BlkMigDevState {
     /* Protected by block migration lock.  */
     int64_t completed_sectors;
 
-    /* Protected by iothread lock / AioContext.  */
+    /* During migration this is protected by iothread lock / AioContext.
+     * Allocation and free happen during setup and cleanup respectively.
+     */
     BdrvDirtyBitmap *dirty_bitmap;
-    Error *blocker;
 } BlkMigDevState;
 
 typedef struct BlkMigBlock {
@@ -339,9 +341,10 @@ static int set_dirty_tracking(void)
     int ret;
 
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
-        /* Creating/dropping dirty bitmaps only requires the big QEMU lock.  */
+        aio_context_acquire(bdrv_get_aio_context(bmds->bs));
         bmds->dirty_bitmap = bdrv_create_dirty_bitmap(bmds->bs, BLOCK_SIZE,
                                                       NULL, NULL);
+        aio_context_release(bdrv_get_aio_context(bmds->bs));
         if (!bmds->dirty_bitmap) {
             ret = -errno;
             goto fail;
@@ -352,7 +355,9 @@ static int set_dirty_tracking(void)
 fail:
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
         if (bmds->dirty_bitmap) {
+            aio_context_acquire(bdrv_get_aio_context(bmds->bs));
             bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
+            aio_context_release(bdrv_get_aio_context(bmds->bs));
         }
     }
     return ret;
@@ -365,8 +370,9 @@ static void unset_dirty_tracking(void)
     BlkMigDevState *bmds;
 
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
-        /* Creating/dropping dirty bitmaps only requires the big QEMU lock.  */
+        aio_context_acquire(bdrv_get_aio_context(bmds->bs));
         bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
+        aio_context_release(bdrv_get_aio_context(bmds->bs));
     }
 }
 
-- 
2.5.0