If you have the chain 'base.qcow2 <- top.qcow2' and want to merge a bitmap from top into base, qemu-img was failing with:
qemu-img: Could not open 'top.qcow2': Could not open backing file: Failed to get shared "write" lock Is another process using the image [base.qcow2]? The easiest fix is to not open the entire backing chain of the source image, so that we aren't worrying about competing BDS visiting the backing image as both a read-only backing of the source and the writeable destination. Fixes: http://bugzilla.redhat.com/1877209 Reported-by: Eyal Shenitzky <eshen...@redhat.com> Signed-off-by: Eric Blake <ebl...@redhat.com> --- qemu-img.c | 3 +- tests/qemu-iotests/291 | 12 ++++++++ tests/qemu-iotests/291.out | 56 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 70 insertions(+), 1 deletion(-) diff --git a/qemu-img.c b/qemu-img.c index eb2fc1f86243..b15098a2f9b3 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -4755,7 +4755,8 @@ static int img_bitmap(int argc, char **argv) } 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; } diff --git a/tests/qemu-iotests/291 b/tests/qemu-iotests/291 index 1e0bb76959bb..4f837b205655 100755 --- a/tests/qemu-iotests/291 +++ b/tests/qemu-iotests/291 @@ -91,6 +91,15 @@ $QEMU_IMG bitmap --remove --image-opts \ driver=$IMGFMT,file.driver=file,file.filename="$TEST_IMG" tmp _img_info --format-specific +echo +echo "=== Merge from top layer into backing image ===" +echo + +$QEMU_IMG rebase -u -F qcow2 -b "$TEST_IMG.base" "$TEST_IMG" +$QEMU_IMG bitmap --add --merge b2 -b "$TEST_IMG" -F $IMGFMT \ + -f $IMGFMT "$TEST_IMG.base" b3 +_img_info --format-specific --backing-chain + echo echo "=== Check bitmap contents ===" echo @@ -107,6 +116,9 @@ $QEMU_IMG map --output=json --image-opts \ nbd_server_start_unix_socket -r -f qcow2 -B b2 "$TEST_IMG" $QEMU_IMG map --output=json --image-opts \ "$IMG,x-dirty-bitmap=qemu:dirty-bitmap:b2" | _filter_qemu_img_map +nbd_server_start_unix_socket -r -f qcow2 -B b3 "$TEST_IMG" +$QEMU_IMG map --output=json --image-opts \ + "$IMG,x-dirty-bitmap=qemu:dirty-bitmap:b3" | _filter_qemu_img_map # success, all done echo '*** done' diff --git a/tests/qemu-iotests/291.out b/tests/qemu-iotests/291.out index ee89a728855f..3990f7aacc7b 100644 --- a/tests/qemu-iotests/291.out +++ b/tests/qemu-iotests/291.out @@ -68,6 +68,59 @@ Format specific information: corrupt: false extended l2: false +=== Merge from top layer into backing image === + +image: TEST_DIR/t.IMGFMT +file format: IMGFMT +virtual size: 10 MiB (10485760 bytes) +cluster_size: 65536 +backing file: TEST_DIR/t.IMGFMT.base +backing file format: IMGFMT +Format specific information: + compat: 1.1 + compression type: zlib + lazy refcounts: false + bitmaps: + [0]: + flags: + name: b1 + granularity: 524288 + [1]: + flags: + [0]: auto + name: b2 + granularity: 65536 + [2]: + flags: + name: b0 + granularity: 65536 + refcount bits: 16 + corrupt: false + extended l2: false + +image: TEST_DIR/t.IMGFMT.base +file format: IMGFMT +virtual size: 10 MiB (10485760 bytes) +cluster_size: 65536 +Format specific information: + compat: 1.1 + compression type: zlib + lazy refcounts: false + bitmaps: + [0]: + flags: + [0]: auto + name: b0 + granularity: 65536 + [1]: + flags: + [0]: auto + name: b3 + granularity: 65536 + refcount bits: 16 + corrupt: false + extended l2: false + === Check bitmap contents === [{ "start": 0, "length": 3145728, "depth": 0, "zero": false, "data": true, "offset": OFFSET}, @@ -79,4 +132,7 @@ Format specific information: [{ "start": 0, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": OFFSET}, { "start": 2097152, "length": 1048576, "depth": 0, "zero": false, "data": false}, { "start": 3145728, "length": 7340032, "depth": 0, "zero": false, "data": true, "offset": OFFSET}] +[{ "start": 0, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": OFFSET}, +{ "start": 2097152, "length": 1048576, "depth": 0, "zero": false, "data": false}, +{ "start": 3145728, "length": 7340032, "depth": 0, "zero": false, "data": true, "offset": OFFSET}] *** done -- 2.28.0
