diff options
| -rw-r--r-- | block/mirror.c | 37 |
1 files changed, 30 insertions, 7 deletions
diff --git a/block/mirror.c b/block/mirror.c index 1a75a47cc3..e5467b0053 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -82,6 +82,7 @@ typedef struct MirrorBlockJob { int max_iov; bool initial_zeroing_ongoing; int in_active_write_counter; + int64_t active_write_bytes_in_flight; bool prepared; bool in_drain; } MirrorBlockJob; @@ -494,6 +495,13 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) } bdrv_dirty_bitmap_unlock(s->dirty_bitmap); + /* + * Wait for concurrent requests to @offset. The next loop will limit the + * copied area based on in_flight_bitmap so we only copy an area that does + * not overlap with concurrent in-flight requests. Still, we would like to + * copy something, so wait until there are at least no more requests to the + * very beginning of the area. + */ mirror_wait_on_conflicts(NULL, s, offset, 1); job_pause_point(&s->common.job); @@ -988,12 +996,6 @@ static int coroutine_fn mirror_run(Job *job, Error **errp) int64_t cnt, delta; bool should_complete; - /* Do not start passive operations while there are active - * writes in progress */ - while (s->in_active_write_counter) { - mirror_wait_for_any_operation(s, true); - } - if (s->ret < 0) { ret = s->ret; goto immediate_exit; @@ -1010,7 +1012,9 @@ static int coroutine_fn mirror_run(Job *job, Error **errp) /* cnt is the number of dirty bytes remaining and s->bytes_in_flight is * the number of bytes currently being processed; together those are * the current remaining operation length */ - job_progress_set_remaining(&s->common.job, s->bytes_in_flight + cnt); + job_progress_set_remaining(&s->common.job, + s->bytes_in_flight + cnt + + s->active_write_bytes_in_flight); /* Note that even when no rate limit is applied we need to yield * periodically with no pending I/O so that bdrv_drain_all() returns. @@ -1071,6 +1075,10 @@ static int coroutine_fn mirror_run(Job *job, Error **errp) s->in_drain = true; bdrv_drained_begin(bs); + + /* Must be zero because we are drained */ + assert(s->in_active_write_counter == 0); + cnt = bdrv_get_dirty_count(s->dirty_bitmap); if (cnt > 0 || mirror_flush(s) < 0) { bdrv_drained_end(bs); @@ -1306,6 +1314,7 @@ do_sync_target_write(MirrorBlockJob *job, MirrorMethod method, } job_progress_increase_remaining(&job->common.job, bytes); + job->active_write_bytes_in_flight += bytes; switch (method) { case MIRROR_METHOD_COPY: @@ -1327,6 +1336,7 @@ do_sync_target_write(MirrorBlockJob *job, MirrorMethod method, abort(); } + job->active_write_bytes_in_flight -= bytes; if (ret >= 0) { job_progress_update(&job->common.job, bytes); } else { @@ -1375,6 +1385,19 @@ static MirrorOp *coroutine_fn active_write_prepare(MirrorBlockJob *s, s->in_active_write_counter++; + /* + * Wait for concurrent requests affecting the area. If there are already + * running requests that are copying off now-to-be stale data in the area, + * we must wait for them to finish before we begin writing fresh data to the + * target so that the write operations appear in the correct order. + * Note that background requests (see mirror_iteration()) in contrast only + * wait for conflicting requests at the start of the dirty area, and then + * (based on the in_flight_bitmap) truncate the area to copy so it will not + * conflict with any requests beyond that. For active writes, however, we + * cannot truncate that area. The request from our parent must be blocked + * until the area is copied in full. Therefore, we must wait for the whole + * area to become free of concurrent requests. + */ mirror_wait_on_conflicts(op, s, offset, bytes); bitmap_set(s->in_flight_bitmap, start_chunk, end_chunk - start_chunk); |