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author | Stefan Hajnoczi <stefanha@redhat.com> | 2016-06-16 17:56:28 +0100 |
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committer | Stefan Hajnoczi <stefanha@redhat.com> | 2016-06-20 14:25:41 +0100 |
commit | 565ac01f8d35236844dd0257a185f81425cd4b6a (patch) | |
tree | 31b21ed53f6d1a0a4f313563c77de9af16b9f474 /block/mirror.c | |
parent | 463e0be101cb5a78ca6ee517d58604c3f3637bcd (diff) | |
download | qemu-565ac01f8d35236844dd0257a185f81425cd4b6a.zip qemu-565ac01f8d35236844dd0257a185f81425cd4b6a.tar.gz qemu-565ac01f8d35236844dd0257a185f81425cd4b6a.tar.bz2 |
mirror: follow AioContext change gracefully
Add block_job_pause_point() calls to mark quiescent points and make sure
to complete in-flight requests when switching AioContexts.
This patch solves undefined behavior in the mirror block job when the
BDS AioContext is changed by dataplane.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 1466096189-6477-8-git-send-email-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/mirror.c')
-rw-r--r-- | block/mirror.c | 43 |
1 files changed, 35 insertions, 8 deletions
diff --git a/block/mirror.c b/block/mirror.c index 075384a..a04ed9c 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -331,6 +331,8 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) mirror_wait_for_io(s); } + block_job_pause_point(&s->common); + /* Find the number of consective dirty chunks following the first dirty * one, and wait for in flight requests in them. */ while (nb_chunks * sectors_per_chunk < (s->buf_size >> BDRV_SECTOR_BITS)) { @@ -582,6 +584,8 @@ static void coroutine_fn mirror_run(void *opaque) if (now - last_pause_ns > SLICE_TIME) { last_pause_ns = now; block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, 0); + } else { + block_job_pause_point(&s->common); } if (block_job_is_cancelled(&s->common)) { @@ -613,6 +617,8 @@ static void coroutine_fn mirror_run(void *opaque) goto immediate_exit; } + block_job_pause_point(&s->common); + cnt = bdrv_get_dirty_count(s->dirty_bitmap); /* s->common.offset contains the number of bytes already processed so * far, cnt is the number of dirty sectors remaining and @@ -795,18 +801,39 @@ static void mirror_complete(BlockJob *job, Error **errp) block_job_enter(&s->common); } +/* There is no matching mirror_resume() because mirror_run() will begin + * iterating again when the job is resumed. + */ +static void coroutine_fn mirror_pause(BlockJob *job) +{ + MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); + + mirror_drain(s); +} + +static void mirror_attached_aio_context(BlockJob *job, AioContext *new_context) +{ + MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); + + blk_set_aio_context(s->target, new_context); +} + static const BlockJobDriver mirror_job_driver = { - .instance_size = sizeof(MirrorBlockJob), - .job_type = BLOCK_JOB_TYPE_MIRROR, - .set_speed = mirror_set_speed, - .complete = mirror_complete, + .instance_size = sizeof(MirrorBlockJob), + .job_type = BLOCK_JOB_TYPE_MIRROR, + .set_speed = mirror_set_speed, + .complete = mirror_complete, + .pause = mirror_pause, + .attached_aio_context = mirror_attached_aio_context, }; static const BlockJobDriver commit_active_job_driver = { - .instance_size = sizeof(MirrorBlockJob), - .job_type = BLOCK_JOB_TYPE_COMMIT, - .set_speed = mirror_set_speed, - .complete = mirror_complete, + .instance_size = sizeof(MirrorBlockJob), + .job_type = BLOCK_JOB_TYPE_COMMIT, + .set_speed = mirror_set_speed, + .complete = mirror_complete, + .pause = mirror_pause, + .attached_aio_context = mirror_attached_aio_context, }; static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target, |