diff mbox

[v11,10/19] block: Add QMP support for streaming to an intermediate layer

Message ID 810feb3cd4b455bd1f225843e5b9aeec3a962f0c.1476450059.git.berto@igalia.com (mailing list archive)
State New, archived
Headers show

Commit Message

Alberto Garcia Oct. 14, 2016, 1:08 p.m. UTC
This patch makes the 'device' parameter of the 'block-stream' command
accept a node name that is not a root node.

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

Signed-off-by: Alberto Garcia <berto@igalia.com>
---
 blockdev.c           | 15 +++++++++------
 qapi/block-core.json | 10 +++++++---
 2 files changed, 16 insertions(+), 9 deletions(-)
diff mbox

Patch

diff --git a/blockdev.c b/blockdev.c
index f13fc69..c01776a 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2937,7 +2937,7 @@  void qmp_block_stream(bool has_job_id, const char *job_id, const char *device,
                       bool has_on_error, BlockdevOnError on_error,
                       Error **errp)
 {
-    BlockDriverState *bs;
+    BlockDriverState *bs, *iter;
     BlockDriverState *base_bs = NULL;
     AioContext *aio_context;
     Error *local_err = NULL;
@@ -2947,7 +2947,7 @@  void qmp_block_stream(bool has_job_id, const char *job_id, const char *device,
         on_error = BLOCKDEV_ON_ERROR_REPORT;
     }
 
-    bs = qmp_get_root_bs(device, errp);
+    bs = bdrv_lookup_bs(device, device, errp);
     if (!bs) {
         return;
     }
@@ -2955,10 +2955,6 @@  void qmp_block_stream(bool has_job_id, const char *job_id, const char *device,
     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) {
@@ -2969,6 +2965,13 @@  void qmp_block_stream(bool has_job_id, const char *job_id, 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 = backing_bs(iter)) {
+        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 1b7aa1b..cbbbbb9 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1464,6 +1464,10 @@ 
 # 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 chain (but always above the base image; see below) 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
@@ -1475,12 +1479,12 @@ 
 # @job-id: #optional identifier for the newly-created block job. If
 #          omitted, the device name will be used. (Since 2.7)
 #
-# @device: the device name or node-name of a root node
+# @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