From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58657) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VDttA-0001hi-VB for qemu-devel@nongnu.org; Mon, 26 Aug 2013 06:19:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VDtt1-000422-T1 for qemu-devel@nongnu.org; Mon, 26 Aug 2013 06:19:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:65404) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VDtt1-00041x-LH for qemu-devel@nongnu.org; Mon, 26 Aug 2013 06:19:03 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r7QAJ3eb026940 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 26 Aug 2013 06:19:03 -0400 From: Max Reitz Date: Mon, 26 Aug 2013 12:18:24 +0200 Message-Id: <1377512306-27382-4-git-send-email-mreitz@redhat.com> In-Reply-To: <1377512306-27382-1-git-send-email-mreitz@redhat.com> References: <1377512306-27382-1-git-send-email-mreitz@redhat.com> Subject: [Qemu-devel] [PATCH 3/5] qcow2: Employ metadata overlap checks List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, Max Reitz The pre-write overlap check function is now called before most of the qcow2 writes (aborting it on collision or other error). Signed-off-by: Max Reitz --- block/qcow2-cache.c | 17 +++++++++++++++++ block/qcow2-cluster.c | 23 +++++++++++++++++++++++ block/qcow2-snapshot.c | 24 ++++++++++++++++++++++++ block/qcow2.c | 38 +++++++++++++++++++++++++++++++++++++- 4 files changed, 101 insertions(+), 1 deletion(-) diff --git a/block/qcow2-cache.c b/block/qcow2-cache.c index 2f3114e..da65297 100644 --- a/block/qcow2-cache.c +++ b/block/qcow2-cache.c @@ -115,6 +115,23 @@ static int qcow2_cache_entry_flush(BlockDriverState *bs, Qcow2Cache *c, int i) } if (c == s->refcount_block_cache) { + ret = qcow2_pre_write_overlap_check(bs, + QCOW2_OL_DEFAULT & ~QCOW2_OL_REFCOUNT_BLOCK, + c->entries[i].offset, s->cluster_size); + } else if (c == s->l2_table_cache) { + ret = qcow2_pre_write_overlap_check(bs, + QCOW2_OL_DEFAULT & ~QCOW2_OL_ACTIVE_L2, + c->entries[i].offset, s->cluster_size); + } else { + ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, + c->entries[i].offset, s->cluster_size); + } + + if (ret) { + return (ret < 0) ? ret : -EIO; + } + + if (c == s->refcount_block_cache) { BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_UPDATE_PART); } else if (c == s->l2_table_cache) { BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE); diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index cca76d4..be35983 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -80,6 +80,15 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size, goto fail; } + /* the L1 position has not yet been updated, so these clusters must + * indeed be completely free */ + ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, + new_l1_table_offset, new_l1_size2); + if (ret) { + ret = (ret < 0) ? ret : -EIO; + goto fail; + } + BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_WRITE_TABLE); for(i = 0; i < s->l1_size; i++) new_l1_table[i] = cpu_to_be64(new_l1_table[i]); @@ -149,6 +158,13 @@ static int write_l1_entry(BlockDriverState *bs, int l1_index) buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]); } + ret = qcow2_pre_write_overlap_check(bs, + QCOW2_OL_DEFAULT & ~QCOW2_OL_ACTIVE_L1, + s->l1_table_offset + 8 * l1_start_index, sizeof(buf)); + if (ret) { + return (ret < 0) ? ret : -EIO; + } + BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); ret = bdrv_pwrite_sync(bs->file, s->l1_table_offset + 8 * l1_start_index, buf, sizeof(buf)); @@ -368,6 +384,13 @@ static int coroutine_fn copy_sectors(BlockDriverState *bs, &s->aes_encrypt_key); } + ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, + ((cluster_offset >> 9) + n_start) << 9, n * BDRV_SECTOR_SIZE); + if (ret) { + ret = (ret < 0) ? ret : -EIO; + goto out; + } + BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE); ret = bdrv_co_writev(bs->file, (cluster_offset >> 9) + n_start, n, &qiov); if (ret < 0) { diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c index 0caac90..6f69ecc 100644 --- a/block/qcow2-snapshot.c +++ b/block/qcow2-snapshot.c @@ -189,6 +189,15 @@ static int qcow2_write_snapshots(BlockDriverState *bs) return ret; } + /* The snapshot list position has not yet been updated, so these clusters + * must indeed be completely free */ + ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, + offset, s->nb_snapshots * sizeof(h)); + if (ret) { + return (ret < 0) ? ret : -EIO; + } + + /* Write all snapshots to the new list */ for(i = 0; i < s->nb_snapshots; i++) { sn = s->snapshots + i; @@ -363,6 +372,13 @@ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info) l1_table[i] = cpu_to_be64(s->l1_table[i]); } + ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, + sn->l1_table_offset, s->l1_size * sizeof(uint64_t)); + if (ret) { + ret = (ret < 0) ? ret : -EIO; + goto fail; + } + ret = bdrv_pwrite(bs->file, sn->l1_table_offset, l1_table, s->l1_size * sizeof(uint64_t)); if (ret < 0) { @@ -475,6 +491,14 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id) goto fail; } + ret = qcow2_pre_write_overlap_check(bs, + QCOW2_OL_DEFAULT & ~QCOW2_OL_ACTIVE_L1, + s->l1_table_offset, cur_l1_bytes); + if (ret) { + ret = (ret < 0) ? ret : -EIO; + goto fail; + } + ret = bdrv_pwrite_sync(bs->file, s->l1_table_offset, sn_l1_table, cur_l1_bytes); if (ret < 0) { diff --git a/block/qcow2.c b/block/qcow2.c index 1d0d7ca..95497c6 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -621,6 +621,8 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags) qcow2_free_snapshots(bs); qcow2_refcount_close(bs); g_free(s->l1_table); + /* else pre-write overlap checks in cache_destroy may crash */ + s->l1_table = NULL; if (s->l2_table_cache) { qcow2_cache_destroy(bs, s->l2_table_cache); } @@ -920,6 +922,14 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, cur_nr_sectors * 512); } + ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, + ((cluster_offset >> 9) + index_in_cluster) << 9, + cur_nr_sectors << 9); + if (ret) { + ret = (ret < 0) ? ret : -EIO; + goto fail; + } + qemu_co_mutex_unlock(&s->lock); BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); trace_qcow2_writev_data(qemu_coroutine_self(), @@ -986,6 +996,8 @@ static void qcow2_close(BlockDriverState *bs) { BDRVQcowState *s = bs->opaque; g_free(s->l1_table); + /* else pre-write overlap checks in cache_destroy may crash */ + s->l1_table = NULL; qcow2_cache_flush(bs, s->l2_table_cache); qcow2_cache_flush(bs, s->refcount_block_cache); @@ -1663,6 +1675,14 @@ static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, if (ret != Z_STREAM_END || out_len >= s->cluster_size) { /* could not compress: write normal cluster */ + + ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, + sector_num << 9, s->cluster_sectors << 9); + if (ret) { + ret = (ret < 0) ? ret : -EIO; + goto fail; + } + ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors); if (ret < 0) { goto fail; @@ -1675,6 +1695,14 @@ static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, goto fail; } cluster_offset &= s->cluster_offset_mask; + + ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, + cluster_offset, out_len); + if (ret) { + ret = (ret < 0) ? ret : -EIO; + goto fail; + } + BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED); ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len); if (ret < 0) { @@ -1752,10 +1780,18 @@ static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, BDRVQcowState *s = bs->opaque; int growable = bs->growable; int ret; + int64_t offset = qcow2_vm_state_offset(s) + pos; BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); bs->growable = 1; - ret = bdrv_pwritev(bs, qcow2_vm_state_offset(s) + pos, qiov); + + ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, offset, + qiov->size); + if (ret) { + return (ret < 0) ? ret : -EIO; + } + + ret = bdrv_pwritev(bs, offset, qiov); bs->growable = growable; return ret; -- 1.8.3.1