From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57624) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1edz9g-0003PF-90 for qemu-devel@nongnu.org; Tue, 23 Jan 2018 09:02:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1edz9a-0005lR-BY for qemu-devel@nongnu.org; Tue, 23 Jan 2018 09:02:28 -0500 From: Kevin Wolf Date: Tue, 23 Jan 2018 15:01:37 +0100 Message-Id: <20180123140201.31163-6-kwolf@redhat.com> In-Reply-To: <20180123140201.31163-1-kwolf@redhat.com> References: <20180123140201.31163-1-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 05/29] qcow2: Repair unaligned preallocated zero clusters List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org From: Max Reitz We can easily repair unaligned preallocated zero clusters by discarding them, so why not do it? Signed-off-by: Max Reitz Message-id: 20171110203759.14018-2-mreitz@redhat.com Reviewed-by: Eric Blake Signed-off-by: Max Reitz --- block/qcow2-refcount.c | 70 ++++++++++++++++++++++++++++++++++++++-------- tests/qemu-iotests/060 | 3 +- tests/qemu-iotests/060.out | 9 ++++++ 3 files changed, 69 insertions(+), 13 deletions(-) diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 3de1ab51ba..92701ab7af 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1508,7 +1508,7 @@ enum { static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, void **refcount_table, int64_t *refcount_table_size, int64_t l2_offset, - int flags) + int flags, BdrvCheckMode fix) { BDRVQcow2State *s = bs->opaque; uint64_t *l2_table, l2_entry; @@ -1579,6 +1579,57 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, next_contiguous_offset = offset + s->cluster_size; } + /* Correct offsets are cluster aligned */ + if (offset_into_cluster(s, offset)) { + if (qcow2_get_cluster_type(l2_entry) == + QCOW2_CLUSTER_ZERO_ALLOC) + { + fprintf(stderr, "%s offset=%" PRIx64 ": Preallocated zero " + "cluster is not properly aligned; L2 entry " + "corrupted.\n", + fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", + offset); + if (fix & BDRV_FIX_ERRORS) { + uint64_t l2e_offset = + l2_offset + (uint64_t)i * sizeof(uint64_t); + + l2_entry = QCOW_OFLAG_ZERO; + l2_table[i] = cpu_to_be64(l2_entry); + ret = qcow2_pre_write_overlap_check(bs, + QCOW2_OL_ACTIVE_L2 | QCOW2_OL_INACTIVE_L2, + l2e_offset, sizeof(uint64_t)); + if (ret < 0) { + fprintf(stderr, "ERROR: Overlap check failed\n"); + res->check_errors++; + /* Something is seriously wrong, so abort checking + * this L2 table */ + goto fail; + } + + ret = bdrv_pwrite_sync(bs->file, l2e_offset, + &l2_table[i], sizeof(uint64_t)); + if (ret < 0) { + fprintf(stderr, "ERROR: Failed to overwrite L2 " + "table entry: %s\n", strerror(-ret)); + res->check_errors++; + /* Do not abort, continue checking the rest of this + * L2 table's entries */ + } else { + res->corruptions_fixed++; + /* Skip marking the cluster as used + * (it is unused now) */ + continue; + } + } else { + res->corruptions++; + } + } else { + fprintf(stderr, "ERROR offset=%" PRIx64 ": Data cluster is " + "not properly aligned; L2 entry corrupted.\n", offset); + res->corruptions++; + } + } + /* Mark cluster as used */ ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, refcount_table_size, @@ -1586,13 +1637,6 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, if (ret < 0) { goto fail; } - - /* Correct offsets are cluster aligned */ - if (offset_into_cluster(s, offset)) { - fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not " - "properly aligned; L2 entry corrupted.\n", offset); - res->corruptions++; - } break; } @@ -1626,7 +1670,7 @@ static int check_refcounts_l1(BlockDriverState *bs, void **refcount_table, int64_t *refcount_table_size, int64_t l1_table_offset, int l1_size, - int flags) + int flags, BdrvCheckMode fix) { BDRVQcow2State *s = bs->opaque; uint64_t *l1_table = NULL, l2_offset, l1_size2; @@ -1681,7 +1725,8 @@ static int check_refcounts_l1(BlockDriverState *bs, /* Process and check L2 entries */ ret = check_refcounts_l2(bs, res, refcount_table, - refcount_table_size, l2_offset, flags); + refcount_table_size, l2_offset, flags, + fix); if (ret < 0) { goto fail; } @@ -1957,7 +2002,8 @@ static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res, /* current L1 table */ ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, - s->l1_table_offset, s->l1_size, CHECK_FRAG_INFO); + s->l1_table_offset, s->l1_size, CHECK_FRAG_INFO, + fix); if (ret < 0) { return ret; } @@ -1966,7 +2012,7 @@ static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res, for (i = 0; i < s->nb_snapshots; i++) { sn = s->snapshots + i; ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, - sn->l1_table_offset, sn->l1_size, 0); + sn->l1_table_offset, sn->l1_size, 0, fix); if (ret < 0) { return ret; } diff --git a/tests/qemu-iotests/060 b/tests/qemu-iotests/060 index 14797dd3b0..6c7407f499 100755 --- a/tests/qemu-iotests/060 +++ b/tests/qemu-iotests/060 @@ -335,7 +335,8 @@ poke_file "$TEST_IMG" "$l2_offset" "\x80\x00\x00\x00\x00\x00\x2a\x01" # Let's write to it! $QEMU_IO -c "write 0 64k" "$TEST_IMG" | _filter_qemu_io -# Can't repair this yet (TODO: We can just deallocate the cluster) +echo '--- Repairing ---' +_check_test_img -r all echo echo '=== Discarding with an unaligned refblock ===' diff --git a/tests/qemu-iotests/060.out b/tests/qemu-iotests/060.out index c4cb7c665e..25d5c3938b 100644 --- a/tests/qemu-iotests/060.out +++ b/tests/qemu-iotests/060.out @@ -317,6 +317,15 @@ discard 65536/65536 bytes at offset 0 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) qcow2: Marking image as corrupt: Preallocated zero cluster offset 0x2a00 unaligned (guest offset: 0); further corruption events will be suppressed write failed: Input/output error +--- Repairing --- +Repairing offset=2a00: Preallocated zero cluster is not properly aligned; L2 entry corrupted. +The following inconsistencies were found and repaired: + + 0 leaked clusters + 1 corruptions + +Double checking the fixed image now... +No errors were found on the image. === Discarding with an unaligned refblock === -- 2.13.6