dump-guest-memory: add dump_in_progress() helper function

For now, it has no effect. It will be used in dump detach support.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-Id: <1455772616-8668-5-git-send-email-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/dump.c b/dump.c
index 434bc60..158d6ea 100644
--- a/dump.c
+++ b/dump.c
@@ -1450,6 +1450,12 @@ static void dump_state_prepare(DumpState *s)
     *s = (DumpState) { .status = DUMP_STATUS_ACTIVE };
 }
 
+bool dump_in_progress(void)
+{
+    DumpState *state = &dump_state_global;
+    return (state->status == DUMP_STATUS_ACTIVE);
+}
+
 static void dump_init(DumpState *s, int fd, bool has_format,
                       DumpGuestMemoryFormat format, bool paging, bool has_filter,
                       int64_t begin, int64_t length, Error **errp)
@@ -1628,6 +1634,13 @@ void qmp_dump_guest_memory(bool paging, const char *file,
     DumpState *s;
     Error *local_err = NULL;
 
+    /* if there is a dump in background, we should wait until the dump
+     * finished */
+    if (dump_in_progress()) {
+        error_setg(errp, "There is a dump in process, please wait.");
+        return;
+    }
+
     /*
      * kdump-compressed format need the whole memory dumped, so paging or
      * filter is not supported here.