From aa1df6fcd4c2dbfd39cac3e1d68208cca61643ce Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Sat, 13 Jun 2015 16:22:23 +0200 Subject: [PATCH 29/42] qcow2: Clean up after refcount rebuild Message-id: <1434212556-3927-30-git-send-email-mreitz@redhat.com> Patchwork-id: 66048 O-Subject: [RHEL-7.2 qemu-kvm PATCH 29/42] qcow2: Clean up after refcount rebuild Bugzilla: 1129893 RH-Acked-by: Jeffrey Cody RH-Acked-by: Fam Zheng RH-Acked-by: Stefan Hajnoczi BZ: 1129893 Because the old refcount structure will be leaked after having rebuilt it, we need to recalculate the refcounts and run a leak-fixing operation afterwards (if leaks should be fixed at all). Signed-off-by: Max Reitz Signed-off-by: Kevin Wolf (cherry picked from commit 791230d8bbd5c09d80845755a54074cd2d8b5a22) Signed-off-by: Max Reitz Signed-off-by: Miroslav Rezanina --- block/qcow2-refcount.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 651ddb6..fe36bbd 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1983,12 +1983,57 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, nb_clusters); if (rebuild && (fix & BDRV_FIX_ERRORS)) { + BdrvCheckResult old_res = *res; + int fresh_leaks = 0; + fprintf(stderr, "Rebuilding refcount structure\n"); ret = rebuild_refcount_structure(bs, res, &refcount_table, &nb_clusters); if (ret < 0) { goto fail; } + + res->corruptions = 0; + res->leaks = 0; + + /* Because the old reftable has been exchanged for a new one the + * references have to be recalculated */ + rebuild = false; + memset(refcount_table, 0, nb_clusters * sizeof(uint16_t)); + ret = calculate_refcounts(bs, res, 0, &rebuild, &refcount_table, + &nb_clusters); + if (ret < 0) { + goto fail; + } + + if (fix & BDRV_FIX_LEAKS) { + /* The old refcount structures are now leaked, fix it; the result + * can be ignored, aside from leaks which were introduced by + * rebuild_refcount_structure() that could not be fixed */ + BdrvCheckResult saved_res = *res; + *res = (BdrvCheckResult){ 0 }; + + compare_refcounts(bs, res, BDRV_FIX_LEAKS, &rebuild, + &highest_cluster, refcount_table, nb_clusters); + if (rebuild) { + fprintf(stderr, "ERROR rebuilt refcount structure is still " + "broken\n"); + } + + /* Any leaks accounted for here were introduced by + * rebuild_refcount_structure() because that function has created a + * new refcount structure from scratch */ + fresh_leaks = res->leaks; + *res = saved_res; + } + + if (res->corruptions < old_res.corruptions) { + res->corruptions_fixed += old_res.corruptions - res->corruptions; + } + if (res->leaks < old_res.leaks) { + res->leaks_fixed += old_res.leaks - res->leaks; + } + res->leaks += fresh_leaks; } else if (fix) { if (rebuild) { fprintf(stderr, "ERROR need to rebuild refcount structures\n"); -- 1.8.3.1