From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52397) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZN2ZU-0007Zm-Lt for qemu-devel@nongnu.org; Wed, 05 Aug 2015 13:33:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZN2ZT-0001IP-PP for qemu-devel@nongnu.org; Wed, 05 Aug 2015 13:33:44 -0400 From: Max Reitz Date: Wed, 5 Aug 2015 19:32:58 +0200 Message-Id: <1438795985-21903-11-git-send-email-mreitz@redhat.com> In-Reply-To: <1438795985-21903-1-git-send-email-mreitz@redhat.com> References: <1438795985-21903-1-git-send-email-mreitz@redhat.com> Subject: [Qemu-devel] [PATCH v6 10/17] qcow2/overlaps: Protect inactive L1 tables List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: Kevin Wolf , qemu-devel@nongnu.org, Stefan Hajnoczi , Max Reitz Keep track of the inactive L1 tables in the metadata list to protect them against accidental modifications. Signed-off-by: Max Reitz Reviewed-by: Eric Blake --- block/qcow2-snapshot.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c index 6d1ae00..95afd87 100644 --- a/block/qcow2-snapshot.c +++ b/block/qcow2-snapshot.c @@ -122,6 +122,21 @@ int qcow2_read_snapshots(BlockDriverState *bs) ret = -EFBIG; goto fail; } + + if (!(s->overlap_check & QCOW2_OL_INACTIVE_L1)) { + continue; + } + + if (sn->l1_size > INT_MAX / sizeof(uint64_t)) { + /* Do not fail opening the image because a snapshot is broken which + * might not be used anyway */ + continue; + } + + qcow2_metadata_list_enter(bs, sn->l1_table_offset, + size_to_clusters(s, sn->l1_size * + sizeof(uint64_t)), + QCOW2_OL_INACTIVE_L1); } assert(offset - s->snapshots_offset <= INT_MAX); @@ -415,6 +430,11 @@ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info) g_free(l1_table); l1_table = NULL; + qcow2_metadata_list_enter(bs, sn->l1_table_offset, + size_to_clusters(s, sn->l1_size * + sizeof(uint64_t)), + QCOW2_OL_INACTIVE_L1); + /* * Increase the refcounts of all clusters and make sure everything is * stable on disk before updating the snapshot table to contain a pointer @@ -635,6 +655,11 @@ int qcow2_snapshot_delete(BlockDriverState *bs, g_free(sn.id_str); g_free(sn.name); + qcow2_metadata_list_remove(bs, sn.l1_table_offset, + size_to_clusters(s, sn.l1_size * + sizeof(uint64_t)), + QCOW2_OL_INACTIVE_L1); + /* * Now decrease the refcounts of clusters referenced by the snapshot and * free the L1 table. -- 2.4.6