bdrv_img_create() polls internally (when calling bdrv_create(), which is
a co_wrapper), so it can't be called while holding the lock of any
AioContext except the current one without causing deadlocks. Drop the
lock around the call in external_snapshot_prepare().
Signed-off-by: Kevin Wolf <kw...@redhat.com>
Message-Id: <20221207131838.239125-11-kw...@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eespo...@redhat.com>
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block.c | 4 ++++
blockdev.c | 4 ++++
2 files changed, 8 insertions(+)
diff --git a/block.c b/block.c
index 6191ac1f44..44d59362d6 100644
--- a/block.c
+++ b/block.c
@@ -6924,6 +6924,10 @@ bool bdrv_op_blocker_is_empty(BlockDriverState *bs)
return true;
}
+/*
+ * Must not be called while holding the lock of an AioContext other than the
+ * current one.
+ */
void bdrv_img_create(const char *filename, const char *fmt,
const char *base_filename, const char *base_fmt,
char *options, uint64_t img_size, int flags, bool quiet,
diff --git a/blockdev.c b/blockdev.c
index 8ffb3d9537..011e48df7b 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1524,10 +1524,14 @@ static void external_snapshot_prepare(BlkActionState
*common,
goto out;
}
bdrv_refresh_filename(state->old_bs);
+
+ aio_context_release(aio_context);
bdrv_img_create(new_image_file, format,
state->old_bs->filename,
state->old_bs->drv->format_name,
NULL, size, flags, false, &local_err);
+ aio_context_acquire(aio_context);
+
if (local_err) {
error_propagate(errp, local_err);
goto out;
--
2.38.1
