From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43526) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZJng2-0002PX-4V for qemu-devel@nongnu.org; Mon, 27 Jul 2015 15:03:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZJng1-0002CV-3g for qemu-devel@nongnu.org; Mon, 27 Jul 2015 15:03:06 -0400 From: Max Reitz Date: Mon, 27 Jul 2015 21:02:17 +0200 Message-Id: <1438023746-10132-9-git-send-email-mreitz@redhat.com> In-Reply-To: <1438023746-10132-1-git-send-email-mreitz@redhat.com> References: <1438023746-10132-1-git-send-email-mreitz@redhat.com> Subject: [Qemu-devel] [PATCH v5 08/17] qcow2/overlaps: Protect active L2 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 active L2 tables in the metadata list to protect them against accidental modifications. Signed-off-by: Max Reitz --- block/qcow2-cluster.c | 2 ++ block/qcow2-refcount.c | 6 ++++++ block/qcow2-snapshot.c | 21 +++++++++++++++++++++ block/qcow2.c | 8 +++++++- 4 files changed, 36 insertions(+), 1 deletion(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index b95f6fe..ec42602 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -285,6 +285,8 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) goto fail; } + qcow2_metadata_list_enter(bs, l2_offset, 1, QCOW2_OL_ACTIVE_L2); + *table = l2_table; trace_qcow2_l2_allocate_done(bs, l1_index, 0); return 0; diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 13799c8..76dd2bc 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1209,6 +1209,12 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs, if (ret < 0) { goto fail; } + if (addend < 0) { + if (!l1_allocated) { + qcow2_metadata_list_remove(bs, l2_offset, 1, + QCOW2_OL_ACTIVE_L2); + } + } } ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits, &refcount); diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c index 05e814d..7add805f 100644 --- a/block/qcow2-snapshot.c +++ b/block/qcow2-snapshot.c @@ -560,6 +560,13 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id) g_free(sn_l1_table); sn_l1_table = NULL; + for (i = 0; i < s->l1_size; i++) { + uint64_t l2_offset = s->l1_table[i] & L1E_OFFSET_MASK; + if (l2_offset) { + qcow2_metadata_list_enter(bs, l2_offset, 1, QCOW2_OL_ACTIVE_L2); + } + } + /* * Update QCOW_OFLAG_COPIED in the active L1 table (it may have changed * when we decreased the refcount of the old snapshot. @@ -724,6 +731,13 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs, sizeof(uint64_t)), QCOW2_OL_ACTIVE_L1); + for (i = 0; i < s->l1_size; i++) { + uint64_t l2_offset = s->l1_table[i] & L1E_OFFSET_MASK; + if (l2_offset) { + qcow2_metadata_list_remove(bs, l2_offset, 1, QCOW2_OL_ACTIVE_L2); + } + } + /* Switch the L1 table */ qemu_vfree(s->l1_table); @@ -740,5 +754,12 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs, sizeof(uint64_t)), QCOW2_OL_ACTIVE_L1); + for (i = 0; i < s->l1_size; i++) { + uint64_t l2_offset = s->l1_table[i] & L1E_OFFSET_MASK; + if (l2_offset) { + qcow2_metadata_list_enter(bs, l2_offset, 1, QCOW2_OL_ACTIVE_L2); + } + } + return 0; } diff --git a/block/qcow2.c b/block/qcow2.c index c186452..b7d0f33 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -863,8 +863,14 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, error_setg_errno(errp, -ret, "Could not read L1 table"); goto fail; } - for(i = 0;i < s->l1_size; i++) { + for (i = 0; i < s->l1_size; i++) { + uint64_t l2_offset; + be64_to_cpus(&s->l1_table[i]); + l2_offset = s->l1_table[i] & L1E_OFFSET_MASK; + if (l2_offset) { + qcow2_metadata_list_enter(bs, l2_offset, 1, QCOW2_OL_ACTIVE_L2); + } } } -- 2.4.6