Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

# gpg: Signature made Mon 31 Oct 2016 16:10:07 GMT
# gpg:                using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (29 commits)
  qapi: allow blockdev-add for NFS
  block/nfs: Introduce runtime_opts in NFS
  block: Mention replication in BlockdevDriver enum docs
  qemu-iotests: test 'offset' and 'size' options in raw driver
  raw_bsd: add offset and size options
  qemu-iotests: Test the 'base-node' parameter of 'block-stream'
  block: Add 'base-node' parameter to the 'block-stream' command
  qemu-iotests: Test streaming to a Quorum child
  qemu-iotests: Add iotests.supports_quorum()
  qemu-iotests: Test block-stream and block-commit in parallel
  qemu-iotests: Test overlapping stream and commit operations
  qemu-iotests: Test block-stream operations in parallel
  qemu-iotests: Test streaming to an intermediate layer
  docs: Document how to stream to an intermediate layer
  block: Add QMP support for streaming to an intermediate layer
  block: Support streaming to an intermediate layer
  block: Block all intermediate nodes in commit_active_start()
  block: Block all nodes involved in the block-commit operation
  block: Check blockers in all nodes involved in a block-commit job
  block: Use block_job_add_bdrv() in backup_start()
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 30 insertions, 13 deletions

diff --git a/docs/live-block-ops.txt b/docs/live-block-ops.txt
index a257087401..2211d14428 100644
--- a/docs/live-block-ops.txt
+++ b/docs/live-block-ops.txt
@@ -4,15 +4,20 @@ LIVE BLOCK OPERATIONS
 High level description of live block operations. Note these are not
 supported for use with the raw format at the moment.
 
+Note also that this document is incomplete and it currently only
+covers the 'stream' operation. Other operations supported by QEMU such
+as 'commit', 'mirror' and 'backup' are not described here yet. Please
+refer to the qapi/block-core.json file for an overview of those.
+
 Snapshot live merge
 ===================
 
 Given a snapshot chain, described in this document in the following
 format:
 
-[A] -> [B] -> [C] -> [D]
+[A] <- [B] <- [C] <- [D] <- [E]
 
-Where the rightmost object ([D] in the example) described is the current
+Where the rightmost object ([E] in the example) described is the current
 image which the guest OS has write access to. To the left of it is its base
 image, and so on accordingly until the leftmost image, which has no
 base.
@@ -21,11 +26,14 @@ The snapshot live merge operation transforms such a chain into a
 smaller one with fewer elements, such as this transformation relative
 to the first example:
 
-[A] -> [D]
+[A] <- [E]
+
+Data is copied in the right direction with destination being the
+rightmost image, but any other intermediate image can be specified
+instead. In this example data is copied from [C] into [D], so [D] can
+be backed by [B]:
 
-Currently only forward merge with target being the active image is
-supported, that is, data copy is performed in the right direction with
-destination being the rightmost image.
+[A] <- [B] <- [D] <- [E]
 
 The operation is implemented in QEMU through image streaming facilities.
 
@@ -35,14 +43,20 @@ streaming operation completes it raises a QMP event. 'block_stream'
 copies data from the backing file(s) into the active image. When finished,
 it adjusts the backing file pointer.
 
-The 'base' parameter specifies an image which data need not be streamed from.
-This image will be used as the backing file for the active image when the
-operation is finished.
+The 'base' parameter specifies an image which data need not be
+streamed from. This image will be used as the backing file for the
+destination image when the operation is finished.
+
+In the first example above, the command would be:
+
+(qemu) block_stream virtio0 file-A.img
 
-In the example above, the command would be:
+In order to specify a destination image different from the active
+(rightmost) one we can use its node name instead.
 
-(qemu) block_stream virtio0 A
+In the second example above, the command would be:
 
+(qemu) block_stream node-D file-B.img
 
 Live block copy
 ===============
diff --git a/docs/qmp-commands.txt b/docs/qmp-commands.txt
index a4732a570c..6afa87298d 100644
--- a/docs/qmp-commands.txt
+++ b/docs/qmp-commands.txt
@@ -750,8 +750,11 @@ Arguments:
 - "job-id": Identifier for the newly-created block job. If omitted,
             the device name will be used. (json-string, optional)
 - "device": The device name or node-name of a root node (json-string)
-- "base": The file name of the backing image above which copying starts
-          (json-string, optional)
+- "base": The file name of the backing image above which copying starts.
+          It cannot be set if 'base-node' is also set (json-string, optional)
+- "base-node": the node name of the backing image above which copying starts.
+               It cannot be set if 'base' is also set.
+               (json-string, optional) (Since 2.8)
 - "backing-file": The backing file string to write into the active layer. This
                   filename is not validated.