commit 469ef350e1a8b5715e620dbf6f6115628e5b566e
author Paolo Bonzini <pbonzini@redhat.com> Thu Apr 12 14:01:02 2012 +0200
committer Kevin Wolf <kwolf@redhat.com> Thu May 10 10:32:11 2012 +0200
tree 876de5201368d945ea9b28f23a44d23bad1a33a9
parent 5f3777945d22248d805fb7c134e206c2d943b77b

block: update in-memory backing file and format

These are needed to print "info block" output correctly.  QCOW2 does this
because it needs it to write the header, but QED does not, and common code
is the right place to do it.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block.c

diff --git a/block.c b/block.c
index 068e41d..dbd60e3 100644
--- a/block.c
+++ b/block.c
@@ -1459,6 +1459,7 @@
     const char *backing_file, const char *backing_fmt)
 {
     BlockDriver *drv = bs->drv;
+    int ret;
 
     /* Backing file format doesn't make sense without a backing file */
     if (backing_fmt && !backing_file) {
@@ -1466,10 +1467,16 @@
     }
 
     if (drv->bdrv_change_backing_file != NULL) {
-        return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
+        ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
     } else {
-        return -ENOTSUP;
+        ret = -ENOTSUP;
     }
+
+    if (ret == 0) {
+        pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
+        pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
+    }
+    return ret;
 }
 
 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,

block/stream.c

diff --git a/block/stream.c b/block/stream.c
index 6724af2..b7e1ad4 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -96,17 +96,6 @@
         bdrv_delete(unused);
     }
     top->backing_hd = base;
-
-    pstrcpy(top->backing_file, sizeof(top->backing_file), "");
-    pstrcpy(top->backing_format, sizeof(top->backing_format), "");
-    if (base_id) {
-        pstrcpy(top->backing_file, sizeof(top->backing_file), base_id);
-        if (base->drv) {
-            pstrcpy(top->backing_format, sizeof(top->backing_format),
-                    base->drv->format_name);
-        }
-    }
-
 }
 
 /*