block-backend: Set werror/rerror defaults in blk_new()

Currently, the default values for werror and rerror have to be set
explicitly with blk_set_on_error() by the callers of blk_new(). The only
caller actually doing this is blockdev_init(), which is called for
BlockBackends created using -drive.

In particular, anonymous BlockBackends created with
-device ...,drive=<node-name> didn't get the correct default set and
instead defaulted to the integer value 0 (= BLOCKDEV_ON_ERROR_REPORT).
This is the intended default for rerror anyway, but the default for
werror should be BLOCKDEV_ON_ERROR_ENOSPC.

Set the defaults in blk_new() instead so that they apply no matter what
way the BlockBackend was created.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/block/block-backend.c b/block/block-backend.c
index 7b1ec5071b..dc0cd57724 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -325,6 +325,9 @@ BlockBackend *blk_new(uint64_t perm, uint64_t shared_perm)
     blk->shared_perm = shared_perm;
     blk_set_enable_write_cache(blk, true);
 
+    blk->on_read_error = BLOCKDEV_ON_ERROR_REPORT;
+    blk->on_write_error = BLOCKDEV_ON_ERROR_ENOSPC;
+
     block_acct_init(&blk->stats);
 
     notifier_list_init(&blk->remove_bs_notifiers);