We're about to move calls to 'fstat' into the thread-pool to avoid
blocking VCPU threads should the system call take too long.
To achieve that we first need to make sure none of its callers is
holding the aio_context lock, otherwise yielding before scheduling the
aiocb handler would result in a deadlock when the qemu_global_mutex is
released and another thread tries to acquire the aio_context.
Signed-off-by: Fabiano Rosas <faro...@suse.de>
---
block/qapi.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/block/qapi.c b/block/qapi.c
index ae6cd1c2ff..cd197abf1f 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -222,6 +222,26 @@ int bdrv_query_snapshot_info_list(BlockDriverState *bs,
return 0;
}
+static int64_t bdrv_get_actual_size(BlockDriverState *bs)
+{
+ int64_t size;
+ AioContext *old_ctx = NULL;
+
+ if (qemu_in_coroutine()) {
+ aio_context_release(bdrv_get_aio_context(bs));
+ old_ctx = bdrv_co_enter(bs);
+ }
+
+ size = bdrv_get_allocated_file_size(bs);
+
+ if (qemu_in_coroutine() && old_ctx) {
+ bdrv_co_leave(bs, old_ctx);
+ aio_context_acquire(bdrv_get_aio_context(bs));
+ }
+
+ return size;
+}
+
/**
* Helper function for other query info functions. Store information about @bs
* in @info, setting @errp on error.
@@ -250,7 +270,7 @@ static void bdrv_do_query_node_info(BlockDriverState *bs,
info->filename = g_strdup(bs->filename);
info->format = g_strdup(bdrv_get_format_name(bs));
info->virtual_size = size;
- info->actual_size = bdrv_get_allocated_file_size(bs);
+ info->actual_size = bdrv_get_actual_size(bs);
info->has_actual_size = info->actual_size >= 0;
if (bs->encrypted) {
info->encrypted = true;
--
2.35.3
