diff options
| -rw-r--r-- | block.c | 7 | ||||
| -rw-r--r-- | block/cow.c | 1 | ||||
| -rw-r--r-- | block/qcow.c | 1 | ||||
| -rw-r--r-- | block/qcow2.c | 1 | ||||
| -rw-r--r-- | block/qed.c | 1 | ||||
| -rw-r--r-- | block/vmdk.c | 1 | ||||
| -rw-r--r-- | include/block/block_int.h | 3 | ||||
| -rwxr-xr-x | tests/qemu-iotests/051 | 5 | ||||
| -rw-r--r-- | tests/qemu-iotests/051.out | 9 |
9 files changed, 29 insertions, 0 deletions
@@ -1192,6 +1192,13 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX); } + if (!bs->drv || !bs->drv->supports_backing) { + ret = -EINVAL; + error_setg(errp, "Driver doesn't support backing files"); + QDECREF(options); + goto free_exit; + } + backing_hd = bdrv_new("", errp); if (bs->backing_format[0] != '\0') { diff --git a/block/cow.c b/block/cow.c index a05a92cada..8f81ee6d56 100644 --- a/block/cow.c +++ b/block/cow.c @@ -414,6 +414,7 @@ static BlockDriver bdrv_cow = { .bdrv_close = cow_close, .bdrv_create = cow_create, .bdrv_has_zero_init = bdrv_has_zero_init_1, + .supports_backing = true, .bdrv_read = cow_co_read, .bdrv_write = cow_co_write, diff --git a/block/qcow.c b/block/qcow.c index 1f2bac8a5f..a874056cf3 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -941,6 +941,7 @@ static BlockDriver bdrv_qcow = { .bdrv_reopen_prepare = qcow_reopen_prepare, .bdrv_create = qcow_create, .bdrv_has_zero_init = bdrv_has_zero_init_1, + .supports_backing = true, .bdrv_co_readv = qcow_co_readv, .bdrv_co_writev = qcow_co_writev, diff --git a/block/qcow2.c b/block/qcow2.c index b9d2fa6632..67e55c9667 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -2418,6 +2418,7 @@ static BlockDriver bdrv_qcow2 = { .bdrv_save_vmstate = qcow2_save_vmstate, .bdrv_load_vmstate = qcow2_load_vmstate, + .supports_backing = true, .bdrv_change_backing_file = qcow2_change_backing_file, .bdrv_refresh_limits = qcow2_refresh_limits, diff --git a/block/qed.c b/block/qed.c index 092e6fb1d2..eddae929eb 100644 --- a/block/qed.c +++ b/block/qed.c @@ -1652,6 +1652,7 @@ static BlockDriver bdrv_qed = { .format_name = "qed", .instance_size = sizeof(BDRVQEDState), .create_opts = &qed_create_opts, + .supports_backing = true, .bdrv_probe = bdrv_qed_probe, .bdrv_rebind = bdrv_qed_rebind, diff --git a/block/vmdk.c b/block/vmdk.c index 83dd6fe4fb..d0de0193fc 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -2180,6 +2180,7 @@ static BlockDriver bdrv_vmdk = { .bdrv_detach_aio_context = vmdk_detach_aio_context, .bdrv_attach_aio_context = vmdk_attach_aio_context, + .supports_backing = true, .create_opts = &vmdk_create_opts, }; diff --git a/include/block/block_int.h b/include/block/block_int.h index 715c761fad..135c5dc0e9 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -100,6 +100,9 @@ struct BlockDriver { */ bool bdrv_needs_filename; + /* Set if a driver can support backing files */ + bool supports_backing; + /* For handling image reopen for split or non-split files */ int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state, BlockReopenQueue *queue, Error **errp); diff --git a/tests/qemu-iotests/051 b/tests/qemu-iotests/051 index 30a712f847..a41334e022 100755 --- a/tests/qemu-iotests/051 +++ b/tests/qemu-iotests/051 @@ -100,6 +100,11 @@ echo echo "info block" | run_qemu -drive file="$TEST_IMG",driver=qcow2,backing.file.filename="$TEST_IMG.orig" -nodefaults +# Drivers that don't support backing files +run_qemu -drive file="$TEST_IMG",driver=raw,backing.file.filename="$TEST_IMG.orig" +run_qemu -drive file="$TEST_IMG",file.backing.driver=file,file.backing.filename="$TEST_IMG.orig" +run_qemu -drive file="$TEST_IMG",file.backing.driver=qcow2,file.backing.file.filename="$TEST_IMG.orig" + echo echo === Enable and disable lazy refcounting on the command line, plus some invalid values === echo diff --git a/tests/qemu-iotests/051.out b/tests/qemu-iotests/051.out index 94c7107250..d7b0f503af 100644 --- a/tests/qemu-iotests/051.out +++ b/tests/qemu-iotests/051.out @@ -53,6 +53,15 @@ ide0-hd0: TEST_DIR/t.qcow2 (qcow2) Backing file: TEST_DIR/t.qcow2.orig (chain depth: 1) (qemu) q[K[Dqu[K[D[Dqui[K[D[D[Dquit[K +Testing: -drive file=TEST_DIR/t.qcow2,driver=raw,backing.file.filename=TEST_DIR/t.qcow2.orig +QEMU_PROG: -drive file=TEST_DIR/t.qcow2,driver=raw,backing.file.filename=TEST_DIR/t.qcow2.orig: could not open disk image TEST_DIR/t.qcow2: Driver doesn't support backing files + +Testing: -drive file=TEST_DIR/t.qcow2,file.backing.driver=file,file.backing.filename=TEST_DIR/t.qcow2.orig +QEMU_PROG: -drive file=TEST_DIR/t.qcow2,file.backing.driver=file,file.backing.filename=TEST_DIR/t.qcow2.orig: could not open disk image TEST_DIR/t.qcow2: Driver doesn't support backing files + +Testing: -drive file=TEST_DIR/t.qcow2,file.backing.driver=qcow2,file.backing.file.filename=TEST_DIR/t.qcow2.orig +QEMU_PROG: -drive file=TEST_DIR/t.qcow2,file.backing.driver=qcow2,file.backing.file.filename=TEST_DIR/t.qcow2.orig: could not open disk image TEST_DIR/t.qcow2: Driver doesn't support backing files + === Enable and disable lazy refcounting on the command line, plus some invalid values === |