Merge remote-tracking branch 'remotes/ericb/tags/pull-bitmaps-2020-09-21' into staging

bitmaps patches for 2020-09-21

- Eric Blake: Improve 'qemu-img bitmap --merge' by not opening backing images

# gpg: Signature made Tue 22 Sep 2020 01:58:31 BST
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-bitmaps-2020-09-21:
  qemu-img: Support bitmap --merge into backing image

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/qemu-img.c b/qemu-img.c
index 3b7700c780..2103507936 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -4779,14 +4779,19 @@ static int img_bitmap(int argc, char **argv)
     filename = argv[optind];
     bitmap = argv[optind + 1];
 
-    blk = img_open(image_opts, filename, fmt, BDRV_O_RDWR, false, false,
-                   false);
+    /*
+     * No need to open backing chains; we will be manipulating bitmaps
+     * directly in this image without reference to image contents.
+     */
+    blk = img_open(image_opts, filename, fmt, BDRV_O_RDWR | BDRV_O_NO_BACKING,
+                   false, false, false);
     if (!blk) {
         goto out;
     }
     bs = blk_bs(blk);
     if (src_filename) {
-        src = img_open(false, src_filename, src_fmt, 0, false, false, false);
+        src = img_open(false, src_filename, src_fmt, BDRV_O_NO_BACKING,
+                       false, false, false);
         if (!src) {
             goto out;
         }