We are on the way to implement internal-backup with fleecing scheme,
which includes backup job copying from fleecing block driver node
(which is target of copy-before-write filter) to final target of
backup. This job doesn't need own filter, as fleecing block driver node
is a kind of snapshot, it's immutable from reader point of view.
Let's add a parameter for backup to not insert filter but instead
unshare writes on source. This way backup job becomes a simple copying
process.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
qapi/block-core.json | 12 +++++++-
include/block/block_int.h | 1 +
block/backup.c | 61 +++++++++++++++++++++++++++++++++++----
block/replication.c | 2 +-
blockdev.c | 1 +
5 files changed, 70 insertions(+), 7 deletions(-)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 8a333136f5..995ca16a5e 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1391,6 +1391,15 @@
# above node specified by @drive. If this option is not
given,
# a node name is autogenerated. (Since: 4.2)
#
+# @immutable-source: If true, assume source is immutable and don't insert
filter
+# as no copy-before-write operations are needed. It will
+# fail if there are existing writers on source node, as
well,
+# any attempt to add writer to source node during backup
will
+# fail. @filter-node-name must not be set.
+# If false, insert copy-before-write filter above source
node
+# (see also @filter-node-name parameter).
+# Default is false. (Since 6.2)
+#
# @x-perf: Performance options. (Since 6.0)
#
# Note: @on-source-error and @on-target-error only affect background
@@ -1407,7 +1416,8 @@
'*on-source-error': 'BlockdevOnError',
'*on-target-error': 'BlockdevOnError',
'*auto-finalize': 'bool', '*auto-dismiss': 'bool',
- '*filter-node-name': 'str', '*x-perf': 'BackupPerf' } }
+ '*filter-node-name': 'str', '*immutable-source': 'bool',
+ '*x-perf': 'BackupPerf' } }
##
# @DriveBackup:
diff --git a/include/block/block_int.h b/include/block/block_int.h
index f1a54db0f8..6571dad061 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -1284,6 +1284,7 @@ BlockJob *backup_job_create(const char *job_id,
BlockDriverState *bs,
BitmapSyncMode bitmap_mode,
bool compress,
const char *filter_node_name,
+ bool immutable_source,
BackupPerf *perf,
BlockdevOnError on_source_error,
BlockdevOnError on_target_error,
diff --git a/block/backup.c b/block/backup.c
index 687d2882bc..a7f4d0d663 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -34,6 +34,14 @@ typedef struct BackupBlockJob {
BlockDriverState *cbw;
BlockDriverState *source_bs;
BlockDriverState *target_bs;
+ BlockBackend *source_blk;
+ BlockBackend *target_blk;
+ /*
+ * Note that if backup runs with filter (immutable-source parameter is
+ * false), @cbw is set but @source_blk and @target_blk are NULL.
+ * Otherwise if backup runs without filter (immutable-source paramter is
+ * true), @cbw is NULL but @source_blk and @target_blk are set.
+ */
BdrvDirtyBitmap *sync_bitmap;
@@ -102,7 +110,17 @@ static void backup_clean(Job *job)
{
BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
block_job_remove_all_bdrv(&s->common);
- bdrv_cbw_drop(s->cbw);
+ if (s->cbw) {
+ assert(!s->source_blk && !s->target_blk);
+ bdrv_cbw_drop(s->cbw);
+ } else {
+ block_copy_state_free(s->bcs);
+ s->bcs = NULL;
+ blk_unref(s->source_blk);
+ s->source_blk = NULL;
+ blk_unref(s->target_blk);
+ s->target_blk = NULL;
+ }
}
void backup_do_checkpoint(BlockJob *job, Error **errp)
@@ -356,6 +374,7 @@ BlockJob *backup_job_create(const char *job_id,
BlockDriverState *bs,
BitmapSyncMode bitmap_mode,
bool compress,
const char *filter_node_name,
+ bool immutable_source,
BackupPerf *perf,
BlockdevOnError on_source_error,
BlockdevOnError on_target_error,
@@ -368,6 +387,7 @@ BlockJob *backup_job_create(const char *job_id,
BlockDriverState *bs,
int64_t cluster_size;
BlockDriverState *cbw = NULL;
BlockCopyState *bcs = NULL;
+ BlockBackend *source_blk = NULL, *target_blk = NULL;
assert(bs);
assert(target);
@@ -376,6 +396,12 @@ BlockJob *backup_job_create(const char *job_id,
BlockDriverState *bs,
assert(sync_mode != MIRROR_SYNC_MODE_INCREMENTAL);
assert(sync_bitmap || sync_mode != MIRROR_SYNC_MODE_BITMAP);
+ if (immutable_source && filter_node_name) {
+ error_setg(errp, "immutable-source and filter-node-name should not "
+ "be set simultaneously");
+ return NULL;
+ }
+
if (bs == target) {
error_setg(errp, "Source and target cannot be the same");
return NULL;
@@ -450,9 +476,30 @@ BlockJob *backup_job_create(const char *job_id,
BlockDriverState *bs,
goto error;
}
- cbw = bdrv_cbw_append(bs, target, filter_node_name, &bcs, errp);
- if (!cbw) {
- goto error;
+ if (immutable_source) {
+ source_blk = blk_new_with_bs(bs, BLK_PERM_CONSISTENT_READ,
+ BLK_PERM_WRITE_UNCHANGED |
+ BLK_PERM_CONSISTENT_READ, errp);
+ if (!source_blk) {
+ goto error;
+ }
+
+ target_blk = blk_new_with_bs(target, BLK_PERM_WRITE,
+ BLK_PERM_CONSISTENT_READ, errp);
+ if (!target_blk) {
+ goto error;
+ }
+
+ bcs = block_copy_state_new(blk_root(source_blk), blk_root(target_blk),
+ NULL, false, errp);
+ if (!bcs) {
+ goto error;
+ }
+ } else {
+ cbw = bdrv_cbw_append(bs, target, filter_node_name, &bcs, errp);
+ if (!cbw) {
+ goto error;
+ }
}
cluster_size = block_copy_cluster_size(bcs);
@@ -464,7 +511,7 @@ BlockJob *backup_job_create(const char *job_id,
BlockDriverState *bs,
}
/* job->len is fixed, so we can't allow resize */
- job = block_job_create(job_id, &backup_job_driver, txn, cbw,
+ job = block_job_create(job_id, &backup_job_driver, txn, cbw ?: bs,
0, BLK_PERM_ALL,
speed, creation_flags, cb, opaque, errp);
if (!job) {
@@ -474,6 +521,8 @@ BlockJob *backup_job_create(const char *job_id,
BlockDriverState *bs,
job->cbw = cbw;
job->source_bs = bs;
job->target_bs = target;
+ job->source_blk = source_blk;
+ job->target_blk = target_blk;
job->on_source_error = on_source_error;
job->on_target_error = on_target_error;
job->sync_mode = sync_mode;
@@ -501,6 +550,8 @@ BlockJob *backup_job_create(const char *job_id,
BlockDriverState *bs,
if (cbw) {
bdrv_cbw_drop(cbw);
}
+ blk_unref(source_blk);
+ blk_unref(target_blk);
return NULL;
}
diff --git a/block/replication.c b/block/replication.c
index 32444b9a8f..5dba4907b8 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -590,7 +590,7 @@ static void replication_start(ReplicationState *rs,
ReplicationMode mode,
s->backup_job = backup_job_create(
NULL, s->secondary_disk->bs,
s->hidden_disk->bs,
0, MIRROR_SYNC_MODE_NONE, NULL, 0, false, NULL,
- &perf,
+ false, &perf,
BLOCKDEV_ON_ERROR_REPORT,
BLOCKDEV_ON_ERROR_REPORT, JOB_INTERNAL,
backup_job_completed, bs, NULL, &local_err);
diff --git a/blockdev.c b/blockdev.c
index 3d8ac368a1..3a8ff7c5ce 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2911,6 +2911,7 @@ static BlockJob *do_backup_common(BackupCommon *backup,
backup->sync, bmap, backup->bitmap_mode,
backup->compress,
backup->filter_node_name,
+ backup->immutable_source,
&perf,
backup->on_source_error,
backup->on_target_error,
--
2.29.2
