Out of the five possible values for MirrorSyncMode, INCREMENTAL and
BITMAP are already rejected up front in mirror_start, leaving NONE,
TOP, and FULL as the remaining values that the code was collapsing
into a single bool is_none_mode. Furthermore, mirror_dirty_init() is
only reachable for modes TOP and FULL, as further guided by
s->zero_target. However, upcoming patches want to further optimize
the pre-zeroing pass of a sync=full mirror in mirror_dirty_init(),
while avoiding that pass on a sync=top action. Instead of throwing
away context by collapsing these two values into
s->is_none_mode=false, it is better to pass s->sync_mode throughout
the entire operation. For active commit, the desired semantics match
sync mode TOP.
Signed-off-by: Eric Blake <ebl...@redhat.com>
---
v4: new patch
---
block/mirror.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index 34c6c5252e1..2599b75d092 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -51,7 +51,7 @@ typedef struct MirrorBlockJob {
BlockDriverState *to_replace;
/* Used to block operations on the drive-mirror-replace target */
Error *replace_blocker;
- bool is_none_mode;
+ MirrorSyncMode sync_mode;
BlockMirrorBackingMode backing_mode;
/* Whether the target image requires explicit zero-initialization */
bool zero_target;
@@ -723,9 +723,10 @@ static int mirror_exit_common(Job *job)
&error_abort);
if (!abort && s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) {
- BlockDriverState *backing = s->is_none_mode ? src : s->base;
+ BlockDriverState *backing;
BlockDriverState *unfiltered_target = bdrv_skip_filters(target_bs);
+ backing = s->sync_mode == MIRROR_SYNC_MODE_NONE ? src : s->base;
if (bdrv_cow_bs(unfiltered_target) != backing) {
bdrv_set_backing_hd(unfiltered_target, backing, &local_err);
if (local_err) {
@@ -1020,7 +1021,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
mirror_free_init(s);
s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
- if (!s->is_none_mode) {
+ if (s->sync_mode != MIRROR_SYNC_MODE_NONE) {
ret = mirror_dirty_init(s);
if (ret < 0 || job_is_cancelled(&s->common.job)) {
goto immediate_exit;
@@ -1711,6 +1712,7 @@ static BlockJob *mirror_start_job(
int creation_flags, BlockDriverState *target,
const char *replaces, int64_t speed,
uint32_t granularity, int64_t buf_size,
+ MirrorSyncMode sync_mode,
BlockMirrorBackingMode backing_mode,
bool zero_target,
BlockdevOnError on_source_error,
@@ -1719,7 +1721,7 @@ static BlockJob *mirror_start_job(
BlockCompletionFunc *cb,
void *opaque,
const BlockJobDriver *driver,
- bool is_none_mode, BlockDriverState *base,
+ BlockDriverState *base,
bool auto_complete, const char *filter_node_name,
bool is_mirror, MirrorCopyMode copy_mode,
bool base_ro,
@@ -1878,7 +1880,7 @@ static BlockJob *mirror_start_job(
s->replaces = g_strdup(replaces);
s->on_source_error = on_source_error;
s->on_target_error = on_target_error;
- s->is_none_mode = is_none_mode;
+ s->sync_mode = sync_mode;
s->backing_mode = backing_mode;
s->zero_target = zero_target;
qatomic_set(&s->copy_mode, copy_mode);
@@ -2015,7 +2017,6 @@ void mirror_start(const char *job_id, BlockDriverState
*bs,
bool unmap, const char *filter_node_name,
MirrorCopyMode copy_mode, Error **errp)
{
- bool is_none_mode;
BlockDriverState *base;
GLOBAL_STATE_CODE();
@@ -2028,14 +2029,13 @@ void mirror_start(const char *job_id, BlockDriverState
*bs,
}
bdrv_graph_rdlock_main_loop();
- is_none_mode = mode == MIRROR_SYNC_MODE_NONE;
base = mode == MIRROR_SYNC_MODE_TOP ? bdrv_backing_chain_next(bs) : NULL;
bdrv_graph_rdunlock_main_loop();
mirror_start_job(job_id, bs, creation_flags, target, replaces,
- speed, granularity, buf_size, backing_mode, zero_target,
- on_source_error, on_target_error, unmap, NULL, NULL,
- &mirror_job_driver, is_none_mode, base, false,
+ speed, granularity, buf_size, mode, backing_mode,
+ zero_target, on_source_error, on_target_error, unmap,
+ NULL, NULL, &mirror_job_driver, base, false,
filter_node_name, true, copy_mode, false, errp);
}
@@ -2061,9 +2061,9 @@ BlockJob *commit_active_start(const char *job_id,
BlockDriverState *bs,
job = mirror_start_job(
job_id, bs, creation_flags, base, NULL, speed, 0, 0,
- MIRROR_LEAVE_BACKING_CHAIN, false,
+ MIRROR_SYNC_MODE_TOP, MIRROR_LEAVE_BACKING_CHAIN, false,
on_error, on_error, true, cb, opaque,
- &commit_active_job_driver, false, base, auto_complete,
+ &commit_active_job_driver, base, auto_complete,
filter_node_name, false, MIRROR_COPY_MODE_BACKGROUND,
base_read_only, errp);
if (!job) {
--
2.49.0
