From 955171e4417bf39edb5503e694501e082a757731 Mon Sep 17 00:00:00 2001
From: Eric Blake <eblake@redhat.com>
Date: Wed, 21 Jul 2021 10:53:48 -0500
Subject: qemu-img: Add --skip-broken-bitmaps for 'convert --bitmaps'

The point of 'qemu-img convert --bitmaps' is to be a convenience for
actions that are already possible through a string of smaller
'qemu-img bitmap' sub-commands.  One situation not accounted for
already is that if a source image contains an inconsistent bitmap (for
example, because a qemu process died abruptly before flushing bitmap
state), the user MUST delete those inconsistent bitmaps before
anything else useful can be done with the image.

We don't want to delete inconsistent bitmaps by default: although a
corrupt bitmap is only a loss of optimization rather than a corruption
of user-visible data, it is still nice to require the user to opt in
to the fact that they are aware of the loss of the bitmap.  Still,
requiring the user to check 'qemu-img info' to see whether bitmaps are
consistent, then use 'qemu-img bitmap --remove' to remove offenders,
all before using 'qemu-img convert', is a lot more work than just
adding a knob 'qemu-img convert --bitmaps --skip-broken-bitmaps' which
opts in to skipping the broken bitmaps.

After testing the new option, also demonstrate the way to manually fix
things (either deleting bad bitmaps, or re-creating them as empty) so
that it is possible to convert without the option.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1946084
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210709153951.2801666-4-eblake@redhat.com>
[eblake: warning message tweak, test enhancements]
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/tests/qemu-img-bitmaps     | 16 +++++++++++-
 tests/qemu-iotests/tests/qemu-img-bitmaps.out | 35 ++++++++++++++++++++++++++-
 2 files changed, 49 insertions(+), 2 deletions(-)

(limited to 'tests')

diff --git a/tests/qemu-iotests/tests/qemu-img-bitmaps b/tests/qemu-iotests/tests/qemu-img-bitmaps
index 09c3d395d1..7a3fe8c3d3 100755
--- a/tests/qemu-iotests/tests/qemu-img-bitmaps
+++ b/tests/qemu-iotests/tests/qemu-img-bitmaps
@@ -144,7 +144,21 @@ _img_info --format-specific | _filter_irrelevant_img_info
 echo
 $QEMU_IMG convert --bitmaps -O qcow2 "$TEST_IMG" "$TEST_IMG.copy" &&
     echo "unexpected success"
-TEST_IMG=$TEST_IMG.copy _img_info --format-specific \
+TEST_IMG="$TEST_IMG.copy" _img_info --format-specific \
+    | _filter_irrelevant_img_info
+# Skipping the broken bitmaps works,...
+echo
+$QEMU_IMG convert --bitmaps --skip-broken-bitmaps \
+    -O qcow2 "$TEST_IMG" "$TEST_IMG.copy"
+TEST_IMG="$TEST_IMG.copy" _img_info --format-specific \
+    | _filter_irrelevant_img_info
+# ...as does removing them
+echo
+_rm_test_img "$TEST_IMG.copy"
+$QEMU_IMG bitmap --remove "$TEST_IMG" b0
+$QEMU_IMG bitmap --remove --add "$TEST_IMG" b2
+$QEMU_IMG convert --bitmaps -O qcow2 "$TEST_IMG" "$TEST_IMG.copy"
+TEST_IMG="$TEST_IMG.copy" _img_info --format-specific \
     | _filter_irrelevant_img_info
 
 # success, all done
diff --git a/tests/qemu-iotests/tests/qemu-img-bitmaps.out b/tests/qemu-iotests/tests/qemu-img-bitmaps.out
index d99c279d0c..e851f0320e 100644
--- a/tests/qemu-iotests/tests/qemu-img-bitmaps.out
+++ b/tests/qemu-iotests/tests/qemu-img-bitmaps.out
@@ -145,6 +145,39 @@ Format specific information:
     corrupt: false
 
 qemu-img: Cannot copy inconsistent bitmap 'b0'
-Try 'qemu-img bitmap --remove' to delete it
+Try --skip-broken-bitmaps, or use 'qemu-img bitmap --remove' to delete it
 qemu-img: Could not open 'TEST_DIR/t.IMGFMT.copy': Could not open 'TEST_DIR/t.IMGFMT.copy': No such file or directory
+
+qemu-img: warning: Skipping inconsistent bitmap 'b0'
+qemu-img: warning: Skipping inconsistent bitmap 'b2'
+image: TEST_DIR/t.IMGFMT.copy
+file format: IMGFMT
+virtual size: 10 MiB (10485760 bytes)
+cluster_size: 65536
+Format specific information:
+    bitmaps:
+        [0]:
+            flags:
+                [0]: auto
+            name: b4
+            granularity: 65536
+    corrupt: false
+
+image: TEST_DIR/t.IMGFMT.copy
+file format: IMGFMT
+virtual size: 10 MiB (10485760 bytes)
+cluster_size: 65536
+Format specific information:
+    bitmaps:
+        [0]:
+            flags:
+                [0]: auto
+            name: b4
+            granularity: 65536
+        [1]:
+            flags:
+                [0]: auto
+            name: b2
+            granularity: 65536
+    corrupt: false
 *** done
-- 
cgit v1.2.3