From a2debf6506266cc65014a1964c71059dce7b0118 Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Tue, 14 Sep 2021 15:24:48 +0300 Subject: qcow2-refcount: introduce fix_l2_entry_by_zero() Split fix_l2_entry_by_zero() out of check_refcounts_l2() to be reused in further patch. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Eric Blake Reviewed-by: Hanna Reitz Message-Id: <20210914122454.141075-5-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz --- block/qcow2-refcount.c | 87 ++++++++++++++++++++++++++++++++++---------------- 1 file changed, 60 insertions(+), 27 deletions(-) (limited to 'block/qcow2-refcount.c') diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 66cbb94ef9..184b96ad63 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1587,6 +1587,54 @@ enum { CHECK_FRAG_INFO = 0x2, /* update BlockFragInfo counters */ }; +/* + * Fix L2 entry by making it QCOW2_CLUSTER_ZERO_PLAIN. + * + * This function decrements res->corruptions on success, so the caller is + * responsible to increment res->corruptions prior to the call. + * + * On failure in-memory @l2_table may be modified. + */ +static int fix_l2_entry_by_zero(BlockDriverState *bs, BdrvCheckResult *res, + uint64_t l2_offset, + uint64_t *l2_table, int l2_index, bool active, + bool *metadata_overlap) +{ + BDRVQcow2State *s = bs->opaque; + int ret; + int idx = l2_index * (l2_entry_size(s) / sizeof(uint64_t)); + uint64_t l2e_offset = l2_offset + (uint64_t)l2_index * l2_entry_size(s); + int ign = active ? QCOW2_OL_ACTIVE_L2 : QCOW2_OL_INACTIVE_L2; + uint64_t l2_entry = has_subclusters(s) ? 0 : QCOW_OFLAG_ZERO; + + set_l2_entry(s, l2_table, l2_index, l2_entry); + ret = qcow2_pre_write_overlap_check(bs, ign, l2e_offset, l2_entry_size(s), + false); + if (metadata_overlap) { + *metadata_overlap = ret < 0; + } + if (ret < 0) { + fprintf(stderr, "ERROR: Overlap check failed\n"); + goto fail; + } + + ret = bdrv_pwrite_sync(bs->file, l2e_offset, &l2_table[idx], + l2_entry_size(s)); + if (ret < 0) { + fprintf(stderr, "ERROR: Failed to overwrite L2 " + "table entry: %s\n", strerror(-ret)); + goto fail; + } + + res->corruptions--; + res->corruptions_fixed++; + return 0; + +fail: + res->check_errors++; + return ret; +} + /* * Increases the refcount in the given refcount table for the all clusters * referenced in the L2 table. While doing so, performs some checks on L2 @@ -1606,6 +1654,7 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, int i, ret; size_t l2_size_bytes = s->l2_size * l2_entry_size(s); g_autofree uint64_t *l2_table = g_malloc(l2_size_bytes); + bool metadata_overlap; /* Read L2 table from disk */ ret = bdrv_pread(bs->file, l2_offset, l2_table, l2_size_bytes); @@ -1685,19 +1734,10 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", offset); if (fix & BDRV_FIX_ERRORS) { - int idx = i * (l2_entry_size(s) / sizeof(uint64_t)); - uint64_t l2e_offset = - l2_offset + (uint64_t)i * l2_entry_size(s); - int ign = active ? QCOW2_OL_ACTIVE_L2 : - QCOW2_OL_INACTIVE_L2; - - l2_entry = has_subclusters(s) ? 0 : QCOW_OFLAG_ZERO; - set_l2_entry(s, l2_table, i, l2_entry); - ret = qcow2_pre_write_overlap_check(bs, ign, - l2e_offset, l2_entry_size(s), false); - if (ret < 0) { - fprintf(stderr, "ERROR: Overlap check failed\n"); - res->check_errors++; + ret = fix_l2_entry_by_zero(bs, res, l2_offset, + l2_table, i, active, + &metadata_overlap); + if (metadata_overlap) { /* * Something is seriously wrong, so abort checking * this L2 table. @@ -1705,26 +1745,19 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, return ret; } - ret = bdrv_pwrite_sync(bs->file, l2e_offset, - &l2_table[idx], - l2_entry_size(s)); - 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--; - res->corruptions_fixed++; + if (ret == 0) { /* * Skip marking the cluster as used * (it is unused now). */ continue; } + + /* + * Failed to fix. + * Do not abort, continue checking the rest of this + * L2 table's entries. + */ } } else { fprintf(stderr, "ERROR offset=%" PRIx64 ": Data cluster is " -- cgit v1.2.3