This is a new version of the patches that add support for streaming to any intermediate layer. You can check the previous version here:
https://lists.gnu.org/archive/html/qemu-devel/2015-02/msg04116.html I followed Kevin's idea to put the ownership of the block job directly on the node that receives the data instead of the root node. There's a few things that I'm not completely sure of and will certainly generate some debate, but I decided to send the code anyway so the actual changes can be seen. Note that this depends on the "Add bdrv_get_device_or_node_name()" patchset I sent last week. Here are the changes: 1) The 'top' parameter of block-stream disappears. 'device' also accepts a node name now, which is used to specify the node where the data will be written. 2) Block jobs can now be owned by any node. This implies: - The block-job-* commands now also accept a node name in the 'device' parameter. I decided not to add a separate 'node-name' parameter, following what we agreed with the 'block-stream' command. - The BlockJobInfo type and BLOCK_JOB_* events will report the node name in the 'device' field if the node does not have a device name. It seems that we had an agreement for the BlockJobInfo case so I decided to follow the same approach for these events. However, in the BLOCK_IMAGE_CORRUPTED case the preferred solution was to add a new 'node-name' field, so I guess we might want to do the same here? - query-block-jobs now searches the whole tree, not just the root nodes. 3) Operations are blocked in all intermediate nodes during the job. If we have a chain [A] -> [B] -> [C] -> [D] -> [E] and we stream from [B] to [E], then [C] and [D] will also be blocked during the job. Since [C] and [D] will be removed from the chain after the job is finished I understand that we don't want to perform any operation with them. 4) As a consequence of 3), op blockers are also checked in all intermediate nodes (not just in the topmost one) before starting a streaming operation. I'm currently checking BLOCK_OP_TYPE_STREAM, but maybe I should use a different op for the intermediate nodes since what I'm going to do there is removing them from the chain? I think those are the most important changes. Any feedback is welcome! Berto v2: - The 'block-stream' command does not have a 'node-name' parameter anymore and reuses 'device' for that purpose. - Block jobs can now be owned by any intermediate node, and not just by the ones at the root. query-block-jobs is updated to reflect that change. - The 'device' parameter of all 'block-job-*' commands can now take a node name. - The BlockJobInfo type and all BLOCK_JOB_* events report the node name in the 'device' field if the node does not have a device name. - All intermediate nodes are blocked (and checked for blockers) during the streaming operation. Alberto Garcia (5): block: allow block jobs in any arbitrary node block: never cancel a streaming job without running stream_complete() block: Support streaming to an intermediate layer block: Add QMP support for streaming to an intermediate layer docs: Document how to stream to an intermediate layer block.c | 4 +++- block/mirror.c | 5 +++-- block/stream.c | 47 ++++++++++++++++++++++++++++++++++++++++++----- blockdev.c | 47 +++++++++++++++++++++++++---------------------- blockjob.c | 17 +++++++++-------- docs/live-block-ops.txt | 32 ++++++++++++++++++++------------ docs/qmp/qmp-events.txt | 8 ++++---- include/qapi/qmp/qerror.h | 3 --- qapi/block-core.json | 28 ++++++++++++++++------------ 9 files changed, 122 insertions(+), 69 deletions(-) -- 2.1.4
