From: Zhao Liu <zhao1.liu@intel.com>
As the comment in qapi/error, passing @errp to error_prepend() requires
ERRP_GUARD():
* = Why, when and how to use ERRP_GUARD() =
*
* Without ERRP_GUARD(), use of the @errp parameter is restricted:
...
* - It should not be passed to error_prepend(), error_vprepend() or
* error_append_hint(), because that doesn't work with &error_fatal.
* ERRP_GUARD() lifts these restrictions.
*
* To use ERRP_GUARD(), add it right at the beginning of the function.
* @errp can then be used without worrying about the argument being
* NULL or &error_fatal.
ERRP_GUARD() could avoid the case when @errp is &error_fatal, the user
can't see this additional information, because exit() happens in
error_setg earlier than information is added [1].
In block/snapshot.c, there are 2 functions passing @errp to
error_prepend() without ERRP_GUARD():
- bdrv_all_delete_snapshot()
- bdrv_all_goto_snapshot()
As the APIs exposed in include/block/snapshot.h, they could be called
by other modules.
To avoid potential issues as [1] said, add missing ERRP_GUARD() at the
beginning of these 2 functions.
[1]: Issue description in the commit message of commit ae7c80a7bd73
("error: New macro ERRP_GUARD()").
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Hanna Reitz <hreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
block/snapshot.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/block/snapshot.c b/block/snapshot.c
index 8694fc0a3eba..8242b4abac41 100644
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -566,6 +566,7 @@ int bdrv_all_delete_snapshot(const char *name,
bool has_devices, strList *devices,
Error **errp)
{
+ ERRP_GUARD();
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
@@ -605,6 +606,7 @@ int bdrv_all_goto_snapshot(const char *name,
bool has_devices, strList *devices,
Error **errp)
{
+ ERRP_GUARD();
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
int ret;