diff mbox

[05/11] block: Add QMP support for streaming to an intermediate layer

Message ID ceea0983c4dfc9a61d278c2d64ed5350a32634aa.1429875134.git.berto@igalia.com
State New
Headers show

Commit Message

Alberto Garcia April 24, 2015, 11:40 a.m. UTC
This patch makes the 'device' parameter of the 'block-stream' command
accept a node name as well as a device name.

In addition to that, operation blockers will be checked in all
intermediate nodes between the top and the base node.

Since qmp_block_stream() now uses the error from bdrv_lookup_bs() and
no longer returns DeviceNotFound, iotest 030 is updated to expect
GenericError instead.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 blockdev.c             | 20 ++++++++++----------
 qapi/block-core.json   | 10 +++++++---
 tests/qemu-iotests/030 |  2 +-
 3 files changed, 18 insertions(+), 14 deletions(-)
diff mbox

Patch

diff --git a/blockdev.c b/blockdev.c
index 677432f..d62e548 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2104,8 +2104,7 @@  void qmp_block_stream(const char *device,
                       bool has_on_error, BlockdevOnError on_error,
                       Error **errp)
 {
-    BlockBackend *blk;
-    BlockDriverState *bs;
+    BlockDriverState *bs, *iter;
     BlockDriverState *base_bs = NULL;
     AioContext *aio_context;
     Error *local_err = NULL;
@@ -2115,20 +2114,14 @@  void qmp_block_stream(const char *device,
         on_error = BLOCKDEV_ON_ERROR_REPORT;
     }
 
-    blk = blk_by_name(device);
-    if (!blk) {
-        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+    bs = bdrv_lookup_bs(device, device, errp);
+    if (!bs) {
         return;
     }
-    bs = blk_bs(blk);
 
     aio_context = bdrv_get_aio_context(bs);
     aio_context_acquire(aio_context);
 
-    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_STREAM, errp)) {
-        goto out;
-    }
-
     if (has_base) {
         base_bs = bdrv_find_backing_image(bs, base);
         if (base_bs == NULL) {
@@ -2139,6 +2132,13 @@  void qmp_block_stream(const char *device,
         base_name = base;
     }
 
+    /* Check for op blockers in the whole chain between bs and base */
+    for (iter = bs; iter && iter != base_bs; iter = iter->backing_hd) {
+        if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_STREAM, errp)) {
+            goto out;
+        }
+    }
+
     /* if we are streaming the entire chain, the result will have no backing
      * file, and specifying one is therefore an error */
     if (base_bs == NULL && has_backing_file) {
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 5126ae0..befc5ce 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1014,6 +1014,10 @@ 
 # with query-block-jobs.  The operation can be stopped before it has completed
 # using the block-job-cancel command.
 #
+# The node that receives the data is called the top image, can be located
+# in any part of the whole chain and can be specified using its device
+# or node name.
+#
 # If a base file is specified then sectors are not copied from that base file and
 # its backing chain.  When streaming completes the image file will have the base
 # file as its backing file.  This can be used to stream a subset of the backing
@@ -1022,12 +1026,12 @@ 
 # On successful completion the image file is updated to drop the backing file
 # and the BLOCK_JOB_COMPLETED event is emitted.
 #
-# @device: the device name
+# @device: the device or node name of the top image
 #
 # @base:   #optional the common backing file name
 #
-# @backing-file: #optional The backing file string to write into the active
-#                          layer. This filename is not validated.
+# @backing-file: #optional The backing file string to write into the top
+#                          image. This filename is not validated.
 #
 #                          If a pathname string is such that it cannot be
 #                          resolved by QEMU, that means that subsequent QMP or
diff --git a/tests/qemu-iotests/030 b/tests/qemu-iotests/030
index 952a524..7ca9b25 100755
--- a/tests/qemu-iotests/030
+++ b/tests/qemu-iotests/030
@@ -107,7 +107,7 @@  class TestSingleDrive(iotests.QMPTestCase):
 
     def test_device_not_found(self):
         result = self.vm.qmp('block-stream', device='nonexistent')
-        self.assert_qmp(result, 'error/class', 'DeviceNotFound')
+        self.assert_qmp(result, 'error/class', 'GenericError')
 
 
 class TestSmallerBackingFile(iotests.QMPTestCase):