From 0a85af351d90e1ae9e06b3bb5290ddf2d5d8b950 Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Fri, 11 Oct 2019 17:28:05 +0200 Subject: [PATCH] qcow2: Write v3-compliant snapshot list on upgrade qcow2 v3 requires every snapshot table entry to have two extra data fields: The 64-bit VM state size, and the virtual disk size. Both are optional for v2 images, so they may not be present. qcow2_upgrade() therefore should update the snapshot table to ensure all entries have these extra data fields. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1727347 Reported-by: Eric Blake Signed-off-by: Max Reitz Reviewed-by: Eric Blake Message-id: 20191011152814.14791-8-mreitz@redhat.com Signed-off-by: Max Reitz --- block/qcow2.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index af08757055..e3a4c44fb7 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -4922,7 +4922,9 @@ static int qcow2_upgrade(BlockDriverState *bs, int target_version, Error **errp) { BDRVQcow2State *s = bs->opaque; + bool need_snapshot_update; int current_version = s->qcow_version; + int i; int ret; /* This is qcow2_upgrade(), not qcow2_downgrade() */ @@ -4931,7 +4933,33 @@ static int qcow2_upgrade(BlockDriverState *bs, int target_version, /* There are no other versions (yet) that you can upgrade to */ assert(target_version == 3); - status_cb(bs, 0, 1, cb_opaque); + status_cb(bs, 0, 2, cb_opaque); + + /* + * In v2, snapshots do not need to have extra data. v3 requires + * the 64-bit VM state size and the virtual disk size to be + * present. + * qcow2_write_snapshots() will always write the list in the + * v3-compliant format. + */ + need_snapshot_update = false; + for (i = 0; i < s->nb_snapshots; i++) { + if (s->snapshots[i].extra_data_size < + sizeof_field(QCowSnapshotExtraData, vm_state_size_large) + + sizeof_field(QCowSnapshotExtraData, disk_size)) + { + need_snapshot_update = true; + break; + } + } + if (need_snapshot_update) { + ret = qcow2_write_snapshots(bs); + if (ret < 0) { + error_setg_errno(errp, -ret, "Failed to update the snapshot table"); + return ret; + } + } + status_cb(bs, 1, 2, cb_opaque); s->qcow_version = target_version; ret = qcow2_update_header(bs); @@ -4940,7 +4968,7 @@ static int qcow2_upgrade(BlockDriverState *bs, int target_version, error_setg_errno(errp, -ret, "Failed to update the image header"); return ret; } - status_cb(bs, 1, 1, cb_opaque); + status_cb(bs, 2, 2, cb_opaque); return 0; }