From 5f658d1b577722111564f51962d6af33d1fe96c6 Mon Sep 17 00:00:00 2001 From: Derrick Stolee Date: Mon, 17 Apr 2023 16:21:40 +0000 Subject: 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 Signed-off-by: Junio C Hamano --- pack-revindex.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) (limited to 'pack-revindex.c') diff --git a/pack-revindex.c b/pack-revindex.c index 007a806994..62a9846470 100644 --- a/pack-revindex.c +++ b/pack-revindex.c @@ -310,16 +310,33 @@ int load_pack_revindex(struct repository *r, struct packed_git *p) */ int verify_pack_revindex(struct packed_git *p) { + int res = 0; + /* Do not bother checking if not initialized. */ - if (!p->revindex_map) - return 0; + if (!p->revindex_map || !p->revindex_data) + return res; if (!hashfile_checksum_valid((const unsigned char *)p->revindex_map, p->revindex_size)) { error(_("invalid checksum")); - return -1; + res = -1; } - return 0; + /* This may fail due to a broken .idx. */ + if (create_pack_revindex_in_memory(p)) + return res; + + for (size_t i = 0; i < p->num_objects; i++) { + uint32_t nr = p->revindex[i].nr; + uint32_t rev_val = get_be32(p->revindex_data + i); + + if (nr != rev_val) { + error(_("invalid rev-index position at %"PRIu64": %"PRIu32" != %"PRIu32""), + (uint64_t)i, nr, rev_val); + res = -1; + } + } + + return res; } int load_midx_revindex(struct multi_pack_index *m) -- cgit v1.2.3