From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:46354) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXZNK-0000BO-8n for qemu-devel@nongnu.org; Mon, 05 Dec 2011 09:18:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RXZNI-00008Q-CD for qemu-devel@nongnu.org; Mon, 05 Dec 2011 09:18:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39230) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXZNH-00008C-Rs for qemu-devel@nongnu.org; Mon, 05 Dec 2011 09:18:32 -0500 From: Kevin Wolf Date: Mon, 5 Dec 2011 15:20:56 +0100 Message-Id: <1323094878-7967-20-git-send-email-kwolf@redhat.com> In-Reply-To: <1323094878-7967-1-git-send-email-kwolf@redhat.com> References: <1323094878-7967-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH 19/41] qcow2: Fix error path in qcow2_snapshot_load_tmp List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: anthony@codemonkey.ws Cc: kwolf@redhat.com, qemu-devel@nongnu.org If the bdrv_read() of the snapshot's L1 table fails, return the right error code and make sure that the old L1 table is still loaded and we don't break the BlockDriverState completely. Signed-off-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi --- block/qcow2-snapshot.c | 34 ++++++++++++++++++++++------------ 1 files changed, 22 insertions(+), 12 deletions(-) diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c index e959ef2..c3112bf 100644 --- a/block/qcow2-snapshot.c +++ b/block/qcow2-snapshot.c @@ -573,32 +573,42 @@ int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab) int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name) { - int i, snapshot_index, l1_size2; + int i, snapshot_index; BDRVQcowState *s = bs->opaque; QCowSnapshot *sn; + uint64_t *new_l1_table; + int new_l1_bytes; + int ret; + assert(bs->read_only); + + /* Search the snapshot */ snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_name); if (snapshot_index < 0) { return -ENOENT; } - sn = &s->snapshots[snapshot_index]; - s->l1_size = sn->l1_size; - l1_size2 = s->l1_size * sizeof(uint64_t); - if (s->l1_table != NULL) { - g_free(s->l1_table); - } - s->l1_table_offset = sn->l1_table_offset; - s->l1_table = g_malloc0(align_offset(l1_size2, 512)); + /* Allocate and read in the snapshot's L1 table */ + new_l1_bytes = s->l1_size * sizeof(uint64_t); + new_l1_table = g_malloc0(align_offset(new_l1_bytes, 512)); - if (bdrv_pread(bs->file, sn->l1_table_offset, - s->l1_table, l1_size2) != l1_size2) { - return -1; + ret = bdrv_pread(bs->file, sn->l1_table_offset, new_l1_table, new_l1_bytes); + if (ret < 0) { + g_free(new_l1_table); + return ret; } + /* Switch the L1 table */ + g_free(s->l1_table); + + s->l1_size = sn->l1_size; + s->l1_table_offset = sn->l1_table_offset; + s->l1_table = new_l1_table; + for(i = 0;i < s->l1_size; i++) { be64_to_cpus(&s->l1_table[i]); } + return 0; } -- 1.7.6.4