block: Fail gracefully when using a format driver on protocol level

Specifying the wrong driver could fail an assertion:

$ qemu-system-x86_64 -drive file.driver=qcow2,file=x
qemu-system-x86_64: block.c:721: bdrv_open_common: Assertion `file !=
((void *)0)' failed.

Signed-off-by: Kevin Wolf <[email protected]>

diff --git a/block.c b/block.c
index 4ad663d3fae8e75e4c3eeddd5f6fc516bc8b3554..bea47c47555dcec297193d6e2ccc6e05d2f795ed 100644 (file)
--- a/block.c
+++ b/block.c
@@ -718,6 +718,13 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
         assert(drv->bdrv_parse_filename || filename != NULL);
         ret = drv->bdrv_file_open(bs, filename, options, open_flags);
     } else {
+        if (file == NULL) {
+            qerror_report(ERROR_CLASS_GENERIC_ERROR, "Can't use '%s' as a "
+                          "block driver for the protocol level",
+                          drv->format_name);
+            ret = -EINVAL;
+            goto free_and_fail;
+        }
         assert(file != NULL);
         bs->file = file;
         ret = drv->bdrv_open(bs, options, open_flags);

diff --git a/tests/qemu-iotests/051 b/tests/qemu-iotests/051
index 8b51de3f3127d5d0b2b071efaeb5c66982f4bcb8..8039e23ab3b53c022d57b60f46c3d7b386727fd2 100755 (executable)
--- a/tests/qemu-iotests/051
+++ b/tests/qemu-iotests/051
@@ -142,6 +142,13 @@ run_qemu -drive media=cdrom,cache=writethrough
 run_qemu -drive media=cdrom,cache=unsafe
 run_qemu -drive media=cdrom,cache=invalid_value
 
+echo
+echo === Specifying the protocol layer ===
+echo
+
+run_qemu -drive file=$TEST_IMG,file.driver=file
+run_qemu -drive file=$TEST_IMG,file.driver=qcow2
+
 # success, all done
 echo "*** done"
 rm -f $seq.full

diff --git a/tests/qemu-iotests/051.out b/tests/qemu-iotests/051.out
index 48456d5b07f631d3a239d54f4b168d7b0676d88c..3d1ac7b7daf8446ef2a9c7d09d57bd9a467c62bc 100644 (file)
--- a/tests/qemu-iotests/051.out
+++ b/tests/qemu-iotests/051.out
@@ -159,4 +159,14 @@ q\e[K\e[Dqu\e[K\e[D\e[Dqui\e[K\e[D\e[D\e[Dquit\e[K
 Testing: -drive media=cdrom,cache=invalid_value
 QEMU_PROG: -drive media=cdrom,cache=invalid_value: invalid cache option
 
+
+=== Specifying the protocol layer ===
+
+Testing: -drive file=TEST_DIR/t.qcow2,file.driver=file
+q\e[K\e[Dqu\e[K\e[D\e[Dqui\e[K\e[D\e[D\e[Dquit\e[K\r
+
+Testing: -drive file=TEST_DIR/t.qcow2,file.driver=qcow2
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,file.driver=qcow2: Can't use 'qcow2' as a block driver for the protocol level
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,file.driver=qcow2: could not open disk image TEST_DIR/t.qcow2: Invalid argument
+
 *** done