Replication functions are mostly called when the BDS is quiescent and
does not have any pending I/O. They do not need to synchronize on
anything since BDS and BB are now thread-safe.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
block/replication.c | 51 ++++++++++++---------------------------------------
1 file changed, 12 insertions(+), 39 deletions(-)
diff --git a/block/replication.c b/block/replication.c
index 5d6e2ec916..7a3b94b90f 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -41,6 +41,8 @@ typedef struct BDRVReplicationState {
Error *blocker;
int orig_hidden_flags;
int orig_secondary_flags;
+
+ /* This field is accessed asynchronously. */
int error;
} BDRVReplicationState;
@@ -201,7 +203,7 @@ static int replication_return_value(BDRVReplicationState
*s, int ret)
}
if (ret < 0) {
- s->error = ret;
+ atomic_set(&s->error, ret);
ret = 0;
}
@@ -311,6 +313,7 @@ static bool
replication_recurse_is_first_non_filter(BlockDriverState *bs,
return bdrv_recurse_is_first_non_filter(bs->file->bs, candidate);
}
+/* Called with no I/O pending. */
static void secondary_do_checkpoint(BDRVReplicationState *s, Error **errp)
{
Error *local_err = NULL;
@@ -405,7 +408,7 @@ static void backup_job_completed(void *opaque, int ret)
if (s->stage != BLOCK_REPLICATION_FAILOVER) {
/* The backup job is cancelled unexpectedly */
- s->error = -EIO;
+ atomic_set(&s->error, -EIO);
}
backup_job_cleanup(bs);
@@ -430,6 +433,7 @@ static bool check_top_bs(BlockDriverState *top_bs,
BlockDriverState *bs)
return false;
}
+/* Called with no I/O pending. */
static void replication_start(ReplicationState *rs, ReplicationMode mode,
Error **errp)
{
@@ -437,24 +441,19 @@ static void replication_start(ReplicationState *rs,
ReplicationMode mode,
BDRVReplicationState *s;
BlockDriverState *top_bs;
int64_t active_length, hidden_length, disk_length;
- AioContext *aio_context;
Error *local_err = NULL;
BlockJob *job;
- aio_context = bdrv_get_aio_context(bs);
- aio_context_acquire(aio_context);
s = bs->opaque;
if (s->stage != BLOCK_REPLICATION_NONE) {
error_setg(errp, "Block replication is running or done");
- aio_context_release(aio_context);
return;
}
if (s->mode != mode) {
error_setg(errp, "The parameter mode's value is invalid, needs %d,"
" but got %d", s->mode, mode);
- aio_context_release(aio_context);
return;
}
@@ -466,21 +465,18 @@ static void replication_start(ReplicationState *rs,
ReplicationMode mode,
if (!s->active_disk || !s->active_disk->bs ||
!s->active_disk->bs->backing) {
error_setg(errp, "Active disk doesn't have backing file");
- aio_context_release(aio_context);
return;
}
s->hidden_disk = s->active_disk->bs->backing;
if (!s->hidden_disk->bs || !s->hidden_disk->bs->backing) {
error_setg(errp, "Hidden disk doesn't have backing file");
- aio_context_release(aio_context);
return;
}
s->secondary_disk = s->hidden_disk->bs->backing;
if (!s->secondary_disk->bs || !bdrv_has_blk(s->secondary_disk->bs)) {
error_setg(errp, "The secondary disk doesn't have block backend");
- aio_context_release(aio_context);
return;
}
@@ -492,7 +488,6 @@ static void replication_start(ReplicationState *rs,
ReplicationMode mode,
active_length != hidden_length || hidden_length != disk_length) {
error_setg(errp, "Active disk, hidden disk, secondary disk's
length"
" are not the same");
- aio_context_release(aio_context);
return;
}
@@ -500,7 +495,6 @@ static void replication_start(ReplicationState *rs,
ReplicationMode mode,
!s->hidden_disk->bs->drv->bdrv_make_empty) {
error_setg(errp,
"Active disk or hidden disk doesn't support
make_empty");
- aio_context_release(aio_context);
return;
}
@@ -508,7 +502,6 @@ static void replication_start(ReplicationState *rs,
ReplicationMode mode,
reopen_backing_file(bs, true, &local_err);
if (local_err) {
error_propagate(errp, local_err);
- aio_context_release(aio_context);
return;
}
@@ -521,7 +514,6 @@ static void replication_start(ReplicationState *rs,
ReplicationMode mode,
!check_top_bs(top_bs, bs)) {
error_setg(errp, "No top_bs or it is invalid");
reopen_backing_file(bs, false, NULL);
- aio_context_release(aio_context);
return;
}
bdrv_op_block_all(top_bs, s->blocker);
@@ -535,13 +527,11 @@ static void replication_start(ReplicationState *rs,
ReplicationMode mode,
if (local_err) {
error_propagate(errp, local_err);
backup_job_cleanup(bs);
- aio_context_release(aio_context);
return;
}
block_job_start(job);
break;
default:
- aio_context_release(aio_context);
abort();
}
@@ -551,48 +541,38 @@ static void replication_start(ReplicationState *rs,
ReplicationMode mode,
secondary_do_checkpoint(s, errp);
}
- s->error = 0;
- aio_context_release(aio_context);
+ atomic_set(&s->error, 0);
}
+/* Called with no I/O pending. */
static void replication_do_checkpoint(ReplicationState *rs, Error **errp)
{
BlockDriverState *bs = rs->opaque;
BDRVReplicationState *s;
- AioContext *aio_context;
- aio_context = bdrv_get_aio_context(bs);
- aio_context_acquire(aio_context);
s = bs->opaque;
if (s->mode == REPLICATION_MODE_SECONDARY) {
secondary_do_checkpoint(s, errp);
}
- aio_context_release(aio_context);
}
static void replication_get_error(ReplicationState *rs, Error **errp)
{
BlockDriverState *bs = rs->opaque;
BDRVReplicationState *s;
- AioContext *aio_context;
- aio_context = bdrv_get_aio_context(bs);
- aio_context_acquire(aio_context);
s = bs->opaque;
if (s->stage != BLOCK_REPLICATION_RUNNING) {
error_setg(errp, "Block replication is not running");
- aio_context_release(aio_context);
return;
}
- if (s->error) {
+ if (atomic_read(&s->error)) {
error_setg(errp, "I/O error occurred");
- aio_context_release(aio_context);
return;
}
- aio_context_release(aio_context);
}
static void replication_done(void *opaque, int ret)
@@ -608,10 +588,10 @@ static void replication_done(void *opaque, int ret)
s->active_disk = NULL;
s->secondary_disk = NULL;
s->hidden_disk = NULL;
- s->error = 0;
+ atomic_set(&s->error, 0);
} else {
s->stage = BLOCK_REPLICATION_FAILOVER_FAILED;
- s->error = -EIO;
+ atomic_set(&s->error, -EIO);
}
}
@@ -619,22 +599,18 @@ static void replication_stop(ReplicationState *rs, bool
failover, Error **errp)
{
BlockDriverState *bs = rs->opaque;
BDRVReplicationState *s;
- AioContext *aio_context;
- aio_context = bdrv_get_aio_context(bs);
- aio_context_acquire(aio_context);
s = bs->opaque;
if (s->stage != BLOCK_REPLICATION_RUNNING) {
error_setg(errp, "Block replication is not running");
- aio_context_release(aio_context);
return;
}
switch (s->mode) {
case REPLICATION_MODE_PRIMARY:
s->stage = BLOCK_REPLICATION_DONE;
- s->error = 0;
+ atomic_set(&s->error, 0);
break;
case REPLICATION_MODE_SECONDARY:
/*
@@ -649,7 +625,6 @@ static void replication_stop(ReplicationState *rs, bool
failover, Error **errp)
if (!failover) {
secondary_do_checkpoint(s, errp);
s->stage = BLOCK_REPLICATION_DONE;
- aio_context_release(aio_context);
return;
}
@@ -659,10 +634,8 @@ static void replication_stop(ReplicationState *rs, bool
failover, Error **errp)
NULL, replication_done, bs, true, errp);
break;
default:
- aio_context_release(aio_context);
abort();
}
- aio_context_release(aio_context);
}
BlockDriver bdrv_replication = {
--
2.13.0
