fsck: check rev-index position values
When checking a rev-index file, it may be helpful to identify exactly which positions are incorrect. Compare the rev-index to a freshly-computed in-memory rev-index and report the comparison failures. This additional check (on top of the checksum validation) can help find files that were corrupt by a single bit flip on-disk or perhaps were written incorrectly due to a bug in Git. Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee committed
Apr 17, 2023 at 16:21 UTC
5f658d1b577722111564f51962d6af33d1fe96c6
2 files changed
+26
-4
pack-revindex.c
+21
-4
@@ -310,16 +310,33 @@ int load_pack_revindex(struct repository *r, struct packed_git *p)
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*/
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int verify_pack_revindex(struct packed_git *p)
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{
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+ int res = 0;
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+
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/* Do not bother checking if not initialized. */
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- if (!p->revindex_map)
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- return 0;
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+ if (!p->revindex_map || !p->revindex_data)
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+ return res;
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if (!hashfile_checksum_valid((const unsigned char *)p->revindex_map, p->revindex_size)) {
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error(_("invalid checksum"));
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- return -1;
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+ res = -1;
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}
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- return 0;
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+ /* This may fail due to a broken .idx. */
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+ if (create_pack_revindex_in_memory(p))
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+ return res;
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+
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+ for (size_t i = 0; i < p->num_objects; i++) {
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+ uint32_t nr = p->revindex[i].nr;
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+ uint32_t rev_val = get_be32(p->revindex_data + i);
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+
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+ if (nr != rev_val) {
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+ error(_("invalid rev-index position at %"PRIu64": %"PRIu32" != %"PRIu32""),
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+ (uint64_t)i, nr, rev_val);
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+ res = -1;
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+ }
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+ }
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+
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+ return res;
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}
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int load_midx_revindex(struct multi_pack_index *m)
t/t5325-reverse-index.sh
+5
@@ -185,4 +185,9 @@ test_expect_success 'fsck catches invalid checksum' '
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"invalid checksum"
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'
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+test_expect_success 'fsck catches invalid row position' '
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+ corrupt_rev_and_verify 14 "\07" \
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+ "invalid rev-index position"
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+'
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+
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test_done