From 450888d96b359d53cc26e99787fe42034988267a Mon Sep 17 00:00:00 2001 From: Peter Krempa Date: Wed, 4 Dec 2019 17:39:16 +0100 Subject: [PATCH] qemu: backup: Merge bitmaps accross the backing chain To allow backups work across external snapshots we need to improve the algorithm which calculates which bitmaps to merge. The algorithm must look for appropriately named bitmaps in the image and possibly descend into a backing image if the current image does not have the bitmap. Signed-off-by: Peter Krempa Reviewed-by: Eric Blake --- src/qemu/qemu_backup.c | 62 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 54 insertions(+), 8 deletions(-) diff --git a/src/qemu/qemu_backup.c b/src/qemu/qemu_backup.c index 14cf6bbef0..294d5999a0 100644 --- a/src/qemu/qemu_backup.c +++ b/src/qemu/qemu_backup.c @@ -173,24 +173,70 @@ qemuBackupDiskDataCleanup(virDomainObjPtr vm, virJSONValuePtr qemuBackupDiskPrepareOneBitmapsChain(virDomainMomentDefPtr *incremental, virStorageSourcePtr backingChain, - virHashTablePtr blockNamedNodeData G_GNUC_UNUSED, - const char *diskdst G_GNUC_UNUSED) + virHashTablePtr blockNamedNodeData, + const char *diskdst) { + qemuBlockNamedNodeDataBitmapPtr bitmap; g_autoptr(virJSONValue) ret = NULL; + size_t incridx = 0; if (!(ret = virJSONValueNewArray())) return NULL; - /* TODO: this code works only if the bitmaps are present on a single node. - * The algorithm needs to be changed so that it looks into the backing chain - * so that we can combine all relevant bitmaps for a given backing chain */ - while (*incremental) { + if (!(bitmap = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData, + backingChain, + incremental[0]->name))) { + virReportError(VIR_ERR_INVALID_ARG, + _("failed to find bitmap '%s' in image '%s%u'"), + incremental[0]->name, diskdst, backingChain->id); + return NULL; + } + + while (bitmap) { + if (bitmap->inconsistent) { + virReportError(VIR_ERR_INVALID_ARG, + _("bitmap '%s' for image '%s%u' is inconsistent"), + bitmap->name, diskdst, backingChain->id); + return NULL; + } + if (qemuMonitorTransactionBitmapMergeSourceAddBitmap(ret, backingChain->nodeformat, - (*incremental)->name) < 0) + bitmap->name) < 0) return NULL; - incremental++; + if (backingChain->backingStore && + (bitmap = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData, + backingChain->backingStore, + incremental[incridx]->name))) { + backingChain = backingChain->backingStore; + continue; + } + + if (incremental[incridx + 1]) { + if ((bitmap = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData, + backingChain, + incremental[incridx + 1]->name))) { + incridx++; + continue; + } + + if (backingChain->backingStore && + (bitmap = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData, + backingChain->backingStore, + incremental[incridx + 1]->name))) { + incridx++; + backingChain = backingChain->backingStore; + continue; + } + + virReportError(VIR_ERR_INVALID_ARG, + _("failed to find bitmap '%s' in image '%s%u'"), + incremental[incridx]->name, diskdst, backingChain->id); + return NULL; + } else { + break; + } } return g_steal_pointer(&ret); -- 2.39.5