From: John Snow <js...@redhat.com>
Teach mirror two new tricks for using bitmaps:
Always: no matter what, we synchronize the copy_bitmap back to the
sync_bitmap. In effect, this allows us resume a failed mirror at a later
date.
Conditional: On success only, we sync the bitmap. This is akin to
incremental backup modes; we can use this bitmap to later refresh a
successfully created mirror.
Originally-by: John Snow <js...@redhat.com>
[FG: add check for bitmap-mode without bitmap
switch to bdrv_dirty_bitmap_merge_internal]
Signed-off-by: Fabian Grünbichler <f.gruenbich...@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lampre...@proxmox.com>
[FE: rebase for 9.0]
Signed-off-by: Fiona Ebner <f.eb...@proxmox.com>
---
The original patch this was based on came from a WIP git branch and
thus has no Signed-off-by trailer from John, see [0]. I added an
Originally-by trailer for now. Let me know if I should drop that and
wait for John's Signed-off-by instead.
[0] https://lore.kernel.org/qemu-devel/1599140071.n44h532eeu.astr...@nora.none/
block/mirror.c | 24 ++++++++++++++++++------
blockdev.c | 3 +++
2 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index 315dff11e2..84155b1f78 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -689,8 +689,6 @@ static int mirror_exit_common(Job *job)
bdrv_unfreeze_backing_chain(mirror_top_bs, target_bs);
}
- bdrv_release_dirty_bitmap(s->dirty_bitmap);
-
/* Make sure that the source BDS doesn't go away during bdrv_replace_node,
* before we can call bdrv_drained_end */
bdrv_ref(src);
@@ -796,6 +794,18 @@ static int mirror_exit_common(Job *job)
bdrv_drained_end(target_bs);
bdrv_unref(target_bs);
+ if (s->sync_bitmap) {
+ if (s->bitmap_mode == BITMAP_SYNC_MODE_ALWAYS ||
+ (s->bitmap_mode == BITMAP_SYNC_MODE_ON_SUCCESS &&
+ job->ret == 0 && ret == 0)) {
+ /* Success; synchronize copy back to sync. */
+ bdrv_clear_dirty_bitmap(s->sync_bitmap, NULL);
+ bdrv_dirty_bitmap_merge_internal(s->sync_bitmap, s->dirty_bitmap,
+ NULL, true);
+ }
+ }
+ bdrv_release_dirty_bitmap(s->dirty_bitmap);
+
bs_opaque->job = NULL;
bdrv_drained_end(src);
@@ -1755,10 +1765,6 @@ static BlockJob *mirror_start_job(
" sync mode",
MirrorSyncMode_str(sync_mode));
return NULL;
- } else if (bitmap_mode != BITMAP_SYNC_MODE_NEVER) {
- error_setg(errp,
- "Bitmap Sync Mode '%s' is not supported by Mirror",
- BitmapSyncMode_str(bitmap_mode));
}
} else if (bitmap) {
error_setg(errp,
@@ -1775,6 +1781,12 @@ static BlockJob *mirror_start_job(
return NULL;
}
granularity = bdrv_dirty_bitmap_granularity(bitmap);
+
+ if (bitmap_mode != BITMAP_SYNC_MODE_NEVER) {
+ if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT, errp)) {
+ return NULL;
+ }
+ }
} else if (granularity == 0) {
granularity = bdrv_get_default_bitmap_granularity(target);
}
diff --git a/blockdev.c b/blockdev.c
index c65d9ded70..aeb9fde9f3 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2873,6 +2873,9 @@ static void blockdev_mirror_common(const char *job_id,
BlockDriverState *bs,
if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
return;
}
+ } else if (has_bitmap_mode) {
+ error_setg(errp, "Cannot specify bitmap sync mode without a bitmap");
+ return;
}
if (!replaces) {
--
2.39.2
