From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: qemu-block@nongnu.org
Cc: qemu-devel@nongnu.org, mreitz@redhat.com, kwolf@redhat.com,
vsementsov@virtuozzo.com, den@openvz.org, ktkhai@virtuozzo.com,
eblake@redhat.com, berto@igalia.com
Subject: [PATCH v2 04/10] qcow2-refcount: introduce fix_l2_entry_by_zero()
Date: Wed, 5 May 2021 09:59:49 +0300 [thread overview]
Message-ID: <20210505065955.13964-5-vsementsov@virtuozzo.com> (raw)
In-Reply-To: <20210505065955.13964-1-vsementsov@virtuozzo.com>
Split fix_l2_entry_by_zero() out of check_refcounts_l2() to be
reused in further patch.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
block/qcow2-refcount.c | 87 +++++++++++++++++++++++++++++-------------
1 file changed, 60 insertions(+), 27 deletions(-)
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 "
--
2.29.2
next prev parent reply other threads:[~2021-05-05 7:02 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-05 6:59 [PATCH v2 00/10] qcow2 check: check some reserved bits and subcluster bitmaps Vladimir Sementsov-Ogievskiy
2021-05-05 6:59 ` [PATCH v2 01/10] qcow2-refcount: improve style of check_refcounts_l2() Vladimir Sementsov-Ogievskiy
2021-05-05 6:59 ` [PATCH v2 02/10] qcow2: compressed read: simplify cluster descriptor passing Vladimir Sementsov-Ogievskiy
2021-05-10 15:36 ` Alberto Garcia
2021-05-05 6:59 ` [PATCH v2 03/10] qcow2: introduce qcow2_parse_compressed_l2_entry() helper Vladimir Sementsov-Ogievskiy
2021-05-05 6:59 ` Vladimir Sementsov-Ogievskiy [this message]
2021-05-05 6:59 ` [PATCH v2 05/10] qcow2-refcount: fix_l2_entry_by_zero(): also zero L2 entry bitmap Vladimir Sementsov-Ogievskiy
2021-05-05 6:59 ` [PATCH v2 06/10] qcow2-refcount: check_refcounts_l2(): check l2_bitmap Vladimir Sementsov-Ogievskiy
2021-05-11 16:49 ` Kirill Tkhai
2021-05-05 6:59 ` [PATCH v2 07/10] qcow2-refcount: check_refcounts_l2(): check reserved bits Vladimir Sementsov-Ogievskiy
2021-05-11 16:54 ` Kirill Tkhai
2021-05-05 6:59 ` [PATCH v2 08/10] qcow2-refcount: improve style of check_refcounts_l1() Vladimir Sementsov-Ogievskiy
2021-05-05 6:59 ` [PATCH v2 09/10] qcow2-refcount: check_refcounts_l1(): check reserved bits Vladimir Sementsov-Ogievskiy
2021-05-11 16:55 ` Kirill Tkhai
2021-05-05 6:59 ` [PATCH v2 10/10] qcow2-refcount: check_refblocks(): add separate message for reserved Vladimir Sementsov-Ogievskiy
2021-05-11 17:09 ` Kirill Tkhai
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