From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60385) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xgs56-0008Qr-Od for qemu-devel@nongnu.org; Wed, 22 Oct 2014 05:19:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xgs50-00023x-Jd for qemu-devel@nongnu.org; Wed, 22 Oct 2014 05:19:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7838) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xgs50-00023t-CI for qemu-devel@nongnu.org; Wed, 22 Oct 2014 05:19:42 -0400 Date: Wed, 22 Oct 2014 11:19:38 +0200 From: Kevin Wolf Message-ID: <20141022091938.GD3188@noname.str.redhat.com> References: <1413965324-14541-1-git-send-email-mreitz@redhat.com> <1413965324-14541-12-git-send-email-mreitz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1413965324-14541-12-git-send-email-mreitz@redhat.com> Subject: Re: [Qemu-devel] [PATCH v7 11/13] qcow2: Clean up after refcount rebuild List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Reitz Cc: qemu-devel@nongnu.org, Stefan Hajnoczi , =?iso-8859-1?Q?Beno=EEt?= Canet Am 22.10.2014 um 10:08 hat Max Reitz geschrieben: > 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 > --- > block/qcow2-refcount.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 45 insertions(+) > > diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c > index 8ca2324..b7c956c 100644 > --- a/block/qcow2-refcount.c > +++ b/block/qcow2-refcount.c > @@ -1962,12 +1962,57 @@ 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->leaks_fixed; Fixed leaks are not accounted for in res->leaks, so you probably want to use that directly without subtracting res->leaks_fixed. > + *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"); Kevin