From 78e9a796a24c4f60c162ee3643c4a251c97ab1d2 Mon Sep 17 00:00:00 2001 Message-ID: <78e9a796a24c4f60c162ee3643c4a251c97ab1d2.1769699749.git.jdenemar@redhat.com> From: Peter Krempa Date: Mon, 26 Jan 2026 16:39:24 +0100 Subject: [PATCH] qemuSnapshotDiskHasBackingDisk: Use proper 'max_depth' when calling 'virStorageSourceGetMetadata' 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 Reviewed-by: Pavel Hrdina (cherry picked from commit 6bcdf4ee59595041c76ed2339c45503723400737) https://issues.redhat.com/browse/RHEL-144089 [rhel-10.2] https://issues.redhat.com/browse/RHEL-144090 [rhel-9.8] --- 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 942ba0d437..c23add5103 100644 --- a/src/qemu/qemu_snapshot.c +++ b/src/qemu/qemu_snapshot.c @@ -3133,7 +3133,9 @@ 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