From: Peter Krempa <[email protected]> The 'max_depth' argument of 'virStorageSourceGetMetadata' doesn't just limit how far the function goes but also fails completely if the chain is deeper than the passed value.
In 'qemuSnapshotDiskHasBackingDisk' we only care about finding the backing image, so just one level below, the passed path, but due to the above setting '1' as max_depth will make the function simply fail every time. Extract and reuse QEMU_DOMAIN_STORAGE_SOURCE_CHAIN_MAX_DEPTH as the detection depth. While '200' layers is overkill for this code, we also start a full qemu instance just to delete an snapshot so this doens't matter and still protects from self-referential images. Signed-off-by: Peter Krempa <[email protected]> --- src/qemu/qemu_domain.c | 2 -- src/qemu/qemu_domain.h | 1 + src/qemu/qemu_snapshot.c | 4 +++- 3 files changed, 4 insertions(+), 3 deletions(-) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index ac56fc7cb4..486a0e7913 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -6297,8 +6297,6 @@ qemuDomainStorageAlias(const char *device, int depth) } -#define QEMU_DOMAIN_STORAGE_SOURCE_CHAIN_MAX_DEPTH 200 - /** * qemuDomainStorageSourceValidateDepth: * @src: storage source chain to validate diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h index 3396f929fd..b9bb338682 100644 --- a/src/qemu/qemu_domain.h +++ b/src/qemu/qemu_domain.h @@ -706,6 +706,7 @@ int qemuDomainCheckDiskStartupPolicy(virQEMUDriver *driver, size_t diskIndex, bool cold_boot); +#define QEMU_DOMAIN_STORAGE_SOURCE_CHAIN_MAX_DEPTH 200 int qemuDomainStorageSourceValidateDepth(virStorageSource *src, int add, const char *diskdst); diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c index 19bb6f8b37..1628c33865 100644 --- a/src/qemu/qemu_snapshot.c +++ b/src/qemu/qemu_snapshot.c @@ -3145,7 +3145,9 @@ qemuSnapshotDiskHasBackingDisk(void *payload, NULL, &uid, &gid); if (!disk->src->backingStore) - ignore_value(virStorageSourceGetMetadata(disk->src, uid, gid, 1, false)); + ignore_value(virStorageSourceGetMetadata(disk->src, uid, gid, + QEMU_DOMAIN_STORAGE_SOURCE_CHAIN_MAX_DEPTH, + false)); if (disk->src->backingStore && virStorageSourceIsSameLocation(disk->src->backingStore, iterdata->diskSrc)) { -- 2.52.0
