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[Qemu-devel] [PATCH 2/3] block: mirror - split out part of mirror_run()
From: |
Jeff Cody |
Subject: |
[Qemu-devel] [PATCH 2/3] block: mirror - split out part of mirror_run() |
Date: |
Sun, 27 Sep 2015 23:29:17 -0400 |
This is code relocation, to pull the part of mirror_run() that
calls mirror_iteration out into a separate function.
Signed-off-by: Jeff Cody <address@hidden>
---
block/mirror.c | 206 ++++++++++++++++++++++++++++++---------------------------
1 file changed, 110 insertions(+), 96 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index 8b3e89b..405e5c4 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -318,6 +318,115 @@ static uint64_t coroutine_fn
mirror_iteration(MirrorBlockJob *s)
return delay_ns;
}
+static int mirror_do_iteration(MirrorBlockJob *s, uint64_t last_pause_ns)
+{
+ int ret;
+
+ BlockDriverState *bs = s->common.bs;
+
+ for (;;) {
+ uint64_t delay_ns = 0;
+ int64_t cnt;
+ bool should_complete;
+
+ if (s->ret < 0) {
+ ret = s->ret;
+ goto immediate_exit;
+ }
+
+ 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
+ * s->sectors_in_flight is the number of sectors currently being
+ * processed; together those are the current total operation length */
+ s->common.len = s->common.offset +
+ (cnt + s->sectors_in_flight) * BDRV_SECTOR_SIZE;
+
+ /* 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.
+ * We do so every SLICE_TIME nanoseconds, or when there is an error,
+ * or when the source is clean, whichever comes first.
+ */
+ if (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - last_pause_ns < SLICE_TIME
+ && s->common.iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
+ if (s->in_flight == MAX_IN_FLIGHT || s->buf_free_count == 0 ||
+ (cnt == 0 && s->in_flight > 0)) {
+ trace_mirror_yield(s, s->in_flight, s->buf_free_count, cnt);
+ s->waiting_for_io = true;
+ qemu_coroutine_yield();
+ s->waiting_for_io = false;
+ continue;
+ } else if (cnt != 0) {
+ delay_ns = mirror_iteration(s);
+ }
+ }
+
+ should_complete = false;
+ if (s->in_flight == 0 && cnt == 0) {
+ trace_mirror_before_flush(s);
+ ret = bdrv_flush(s->target);
+ if (ret < 0) {
+ if (mirror_error_action(s, false, -ret) ==
+ BLOCK_ERROR_ACTION_REPORT) {
+ goto immediate_exit;
+ }
+ } else {
+ /* We're out of the streaming phase. From now on, if the job
+ * is cancelled we will actually complete all pending I/O and
+ * report completion. This way, block-job-cancel will leave
+ * the target in a consistent state.
+ */
+ if (!s->synced) {
+ block_job_event_ready(&s->common);
+ s->synced = true;
+ }
+
+ should_complete = s->should_complete ||
+ block_job_is_cancelled(&s->common);
+ cnt = bdrv_get_dirty_count(s->dirty_bitmap);
+ }
+ }
+
+ if (cnt == 0 && should_complete) {
+ /* The dirty bitmap is not updated while operations are pending.
+ * If we're about to exit, wait for pending operations before
+ * calling bdrv_get_dirty_count(bs), or we may exit while the
+ * source has dirty data to copy!
+ *
+ * Note that I/O can be submitted by the guest while
+ * mirror_populate runs.
+ */
+ trace_mirror_before_drain(s, cnt);
+ bdrv_drain(bs);
+ cnt = bdrv_get_dirty_count(s->dirty_bitmap);
+ }
+
+ ret = 0;
+ trace_mirror_before_sleep(s, cnt, s->synced, delay_ns);
+ if (!s->synced) {
+ block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns);
+ if (block_job_is_cancelled(&s->common)) {
+ break;
+ }
+ } else if (!should_complete) {
+ delay_ns = (s->in_flight == 0 && cnt == 0 ? SLICE_TIME : 0);
+ block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns);
+ } else if (cnt == 0) {
+ /* The two disks are in sync. Exit and report successful
+ * completion.
+ */
+ assert(QLIST_EMPTY(&bs->tracked_requests));
+ s->common.cancelled = false;
+ break;
+ }
+ last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+ }
+
+immediate_exit:
+ return ret;
+
+}
+
static void mirror_free_init(MirrorBlockJob *s)
{
int granularity = s->granularity;
@@ -485,103 +594,8 @@ static void coroutine_fn mirror_run(void *opaque)
}
bdrv_dirty_iter_init(s->dirty_bitmap, &s->hbi);
- for (;;) {
- uint64_t delay_ns = 0;
- int64_t cnt;
- bool should_complete;
- if (s->ret < 0) {
- ret = s->ret;
- goto immediate_exit;
- }
-
- 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
- * s->sectors_in_flight is the number of sectors currently being
- * processed; together those are the current total operation length */
- s->common.len = s->common.offset +
- (cnt + s->sectors_in_flight) * BDRV_SECTOR_SIZE;
-
- /* 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.
- * We do so every SLICE_TIME nanoseconds, or when there is an error,
- * or when the source is clean, whichever comes first.
- */
- if (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - last_pause_ns <
SLICE_TIME &&
- s->common.iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
- if (s->in_flight == MAX_IN_FLIGHT || s->buf_free_count == 0 ||
- (cnt == 0 && s->in_flight > 0)) {
- trace_mirror_yield(s, s->in_flight, s->buf_free_count, cnt);
- s->waiting_for_io = true;
- qemu_coroutine_yield();
- s->waiting_for_io = false;
- continue;
- } else if (cnt != 0) {
- delay_ns = mirror_iteration(s);
- }
- }
-
- should_complete = false;
- if (s->in_flight == 0 && cnt == 0) {
- trace_mirror_before_flush(s);
- ret = bdrv_flush(s->target);
- if (ret < 0) {
- if (mirror_error_action(s, false, -ret) ==
- BLOCK_ERROR_ACTION_REPORT) {
- goto immediate_exit;
- }
- } else {
- /* We're out of the streaming phase. From now on, if the job
- * is cancelled we will actually complete all pending I/O and
- * report completion. This way, block-job-cancel will leave
- * the target in a consistent state.
- */
- if (!s->synced) {
- block_job_event_ready(&s->common);
- s->synced = true;
- }
-
- should_complete = s->should_complete ||
- block_job_is_cancelled(&s->common);
- cnt = bdrv_get_dirty_count(s->dirty_bitmap);
- }
- }
-
- if (cnt == 0 && should_complete) {
- /* The dirty bitmap is not updated while operations are pending.
- * If we're about to exit, wait for pending operations before
- * calling bdrv_get_dirty_count(bs), or we may exit while the
- * source has dirty data to copy!
- *
- * Note that I/O can be submitted by the guest while
- * mirror_populate runs.
- */
- trace_mirror_before_drain(s, cnt);
- bdrv_drain(bs);
- cnt = bdrv_get_dirty_count(s->dirty_bitmap);
- }
-
- ret = 0;
- trace_mirror_before_sleep(s, cnt, s->synced, delay_ns);
- if (!s->synced) {
- block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns);
- if (block_job_is_cancelled(&s->common)) {
- break;
- }
- } else if (!should_complete) {
- delay_ns = (s->in_flight == 0 && cnt == 0 ? SLICE_TIME : 0);
- block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns);
- } else if (cnt == 0) {
- /* The two disks are in sync. Exit and report successful
- * completion.
- */
- assert(QLIST_EMPTY(&bs->tracked_requests));
- s->common.cancelled = false;
- break;
- }
- last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
- }
+ ret = mirror_do_iteration(s, last_pause_ns);
immediate_exit:
if (s->in_flight > 0) {
--
1.9.3