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-rw-r--r--block.c46
-rw-r--r--include/block/block_int.h2
2 files changed, 38 insertions, 10 deletions
diff --git a/block.c b/block.c
index b331eb9d38..c0ccc27c73 100644
--- a/block.c
+++ b/block.c
@@ -3609,18 +3609,34 @@ AioContext *bdrv_get_aio_context(BlockDriverState *bs)
return bs->aio_context;
}
+static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier *ban)
+{
+ QLIST_REMOVE(ban, list);
+ g_free(ban);
+}
+
void bdrv_detach_aio_context(BlockDriverState *bs)
{
- BdrvAioNotifier *baf;
+ BdrvAioNotifier *baf, *baf_tmp;
BdrvChild *child;
if (!bs->drv) {
return;
}
- QLIST_FOREACH(baf, &bs->aio_notifiers, list) {
- baf->detach_aio_context(baf->opaque);
+ assert(!bs->walking_aio_notifiers);
+ bs->walking_aio_notifiers = true;
+ QLIST_FOREACH_SAFE(baf, &bs->aio_notifiers, list, baf_tmp) {
+ if (baf->deleted) {
+ bdrv_do_remove_aio_context_notifier(baf);
+ } else {
+ baf->detach_aio_context(baf->opaque);
+ }
}
+ /* Never mind iterating again to check for ->deleted. bdrv_close() will
+ * remove remaining aio notifiers if we aren't called again.
+ */
+ bs->walking_aio_notifiers = false;
if (bs->drv->bdrv_detach_aio_context) {
bs->drv->bdrv_detach_aio_context(bs);
@@ -3635,7 +3651,7 @@ void bdrv_detach_aio_context(BlockDriverState *bs)
void bdrv_attach_aio_context(BlockDriverState *bs,
AioContext *new_context)
{
- BdrvAioNotifier *ban;
+ BdrvAioNotifier *ban, *ban_tmp;
BdrvChild *child;
if (!bs->drv) {
@@ -3651,9 +3667,16 @@ void bdrv_attach_aio_context(BlockDriverState *bs,
bs->drv->bdrv_attach_aio_context(bs, new_context);
}
- QLIST_FOREACH(ban, &bs->aio_notifiers, list) {
- ban->attached_aio_context(new_context, ban->opaque);
+ assert(!bs->walking_aio_notifiers);
+ bs->walking_aio_notifiers = true;
+ QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_tmp) {
+ if (ban->deleted) {
+ bdrv_do_remove_aio_context_notifier(ban);
+ } else {
+ ban->attached_aio_context(new_context, ban->opaque);
+ }
}
+ bs->walking_aio_notifiers = false;
}
void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
@@ -3695,11 +3718,14 @@ void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
if (ban->attached_aio_context == attached_aio_context &&
ban->detach_aio_context == detach_aio_context &&
- ban->opaque == opaque)
+ ban->opaque == opaque &&
+ ban->deleted == false)
{
- QLIST_REMOVE(ban, list);
- g_free(ban);
-
+ if (bs->walking_aio_notifiers) {
+ ban->deleted = true;
+ } else {
+ bdrv_do_remove_aio_context_notifier(ban);
+ }
return;
}
}
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 688c6be009..205715600b 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -361,6 +361,7 @@ typedef struct BdrvAioNotifier {
void (*detach_aio_context)(void *opaque);
void *opaque;
+ bool deleted;
QLIST_ENTRY(BdrvAioNotifier) list;
} BdrvAioNotifier;
@@ -427,6 +428,7 @@ struct BlockDriverState {
* BDS may register themselves in this list to be notified of changes
* regarding this BDS's context */
QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
+ bool walking_aio_notifiers; /* to make removal during iteration safe */
char filename[PATH_MAX];
char backing_file[PATH_MAX]; /* if non zero, the image is a diff of