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Re: [Qemu-devel] [PATCH v2 00/11] block: allow blockjobs to coexist with
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] [PATCH v2 00/11] block: allow blockjobs to coexist with dataplane |
Date: |
Wed, 29 Oct 2014 12:11:31 +0000 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Tue, Oct 21, 2014 at 12:03:49PM +0100, Stefan Hajnoczi wrote:
> v2:
> * Protect block_job_defer_to_main_loop_bh() against AioContext change [Max]
> * Drop unnecessary if (buf) around qemu_vfree(buf) [Max]
>
> Almost all the infrastructure is in place to make blockjobs safe for use with
> dataplane:
>
> * Op blockers all us to exclude commands that could conflict with a blockjob
> or dataplane.
>
> * AioContext acquire/release allows threads to temporarily access a
> BlockDriverState that is running in another thread.
>
> This series introduces a few additional helpers:
>
> * block_job_defer_to_main_loop() which allows blockjobs to run their
> completion code in the QEMU main loop. This is necessary because some
> operations are not safe outside the QEMU global mutex.
>
> * bdrv_drain() which can be used in limited cases to wait for in-flight
> requests to complete (as opposed to the global bdrv_drain_all() function).
>
> The approach taken in this series is to convert the blockdev.c monitor command
> so it acquires the BlockDriverState's AioContext. Normally only 1 AioContext
> is involved at a time but the mirror job's to_replace argument can involve a
> second AioContext.
>
> Then the block job code itself is converted to defer main loop code using
> block_job_defer_to_main_loop().
>
> Example:
>
> $ qemu-system-x86_64 -enable-kvm -m 1024 \
> -drive if=none,id=drive0,file=test.img \
> -object iothread,iothread0 \
> -device virtio-blk-pci,drive=drive0,iothread=iothread0
> (qemu) drive_mirror drive0 test2.img
>
> Stefan Hajnoczi (11):
> block: acquire AioContext in generic blockjob QMP commands
> blockdev: acquire AioContext in do_qmp_query_block_jobs_one()
> blockdev: acquire AioContext in blockdev_mark_auto_del()
> blockdev: add note that block_job_cb() must be thread-safe
> blockjob: add block_job_defer_to_main_loop()
> block: add bdrv_drain()
> block: let backup blockjob run in BDS AioContext
> block: let stream blockjob run in BDS AioContext
> block: let mirror blockjob run in BDS AioContext
> block: let commit blockjob run in BDS AioContext
> block: declare blockjobs and dataplane friends!
>
> block.c | 49 +++++++++--
> block/backup.c | 21 ++++-
> block/commit.c | 70 ++++++++++------
> block/mirror.c | 85 +++++++++++++------
> block/stream.c | 50 +++++++----
> blockdev.c | 179
> +++++++++++++++++++++++++++++-----------
> blockjob.c | 46 +++++++++++
> hw/block/dataplane/virtio-blk.c | 5 ++
> include/block/block.h | 1 +
> include/block/blockjob.h | 19 +++++
> 10 files changed, 402 insertions(+), 123 deletions(-)
Applied to my block tree:
https://github.com/stefanha/qemu/commits/block
Stefan
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- [Qemu-devel] [PATCH v2 04/11] blockdev: add note that block_job_cb() must be thread-safe, (continued)
- [Qemu-devel] [PATCH v2 04/11] blockdev: add note that block_job_cb() must be thread-safe, Stefan Hajnoczi, 2014/10/21
- [Qemu-devel] [PATCH v2 05/11] blockjob: add block_job_defer_to_main_loop(), Stefan Hajnoczi, 2014/10/21
- [Qemu-devel] [PATCH v2 06/11] block: add bdrv_drain(), Stefan Hajnoczi, 2014/10/21
- [Qemu-devel] [PATCH v2 07/11] block: let backup blockjob run in BDS AioContext, Stefan Hajnoczi, 2014/10/21
- [Qemu-devel] [PATCH v2 09/11] block: let mirror blockjob run in BDS AioContext, Stefan Hajnoczi, 2014/10/21
- [Qemu-devel] [PATCH v2 08/11] block: let stream blockjob run in BDS AioContext, Stefan Hajnoczi, 2014/10/21
- [Qemu-devel] [PATCH v2 10/11] block: let commit blockjob run in BDS AioContext, Stefan Hajnoczi, 2014/10/21
- [Qemu-devel] [PATCH v2 11/11] block: declare blockjobs and dataplane friends!, Stefan Hajnoczi, 2014/10/21
- Re: [Qemu-devel] [PATCH v2 00/11] block: allow blockjobs to coexist with dataplane,
Stefan Hajnoczi <=