Merge branch 'tb/idx-midx-race-fix'

Processes that access packdata while the .idx file gets removed
(e.g. while repacking) did not fail or fall back gracefully as they
could.

* tb/idx-midx-race-fix:
  midx.c: protect against disappearing packs
  packfile.c: protect against disappearing indexes
This commit is contained in:
Junio C Hamano 2020-12-08 15:11:18 -08:00
commit 6bac6a1ef9
3 changed files with 31 additions and 20 deletions

2
midx.c
View File

@ -298,7 +298,7 @@ static int nth_midxed_pack_entry(struct repository *r,
pack_int_id = nth_midxed_pack_int_id(m, pos);
if (prepare_midx_pack(r, m, pack_int_id))
die(_("error preparing packfile from multi-pack-index"));
return 0;
p = m->packs[pack_int_id];
/*

View File

@ -514,19 +514,8 @@ static int open_packed_git_1(struct packed_git *p)
ssize_t read_result;
const unsigned hashsz = the_hash_algo->rawsz;
if (!p->index_data) {
struct multi_pack_index *m;
const char *pack_name = pack_basename(p);
for (m = the_repository->objects->multi_pack_index;
m; m = m->next) {
if (midx_contains_pack(m, pack_name))
break;
}
if (!m && open_pack_index(p))
return error("packfile %s index unavailable", p->pack_name);
}
if (open_pack_index(p))
return error("packfile %s index unavailable", p->pack_name);
if (!pack_max_fds) {
unsigned int max_fds = get_max_fd_limit();
@ -567,10 +556,6 @@ static int open_packed_git_1(struct packed_git *p)
" supported (try upgrading GIT to a newer version)",
p->pack_name, ntohl(hdr.hdr_version));
/* Skip index checking if in multi-pack-index */
if (!p->index_data)
return 0;
/* Verify the pack matches its index. */
if (p->num_objects != ntohl(hdr.hdr_entries))
return error("packfile %s claims to have %"PRIu32" objects"

View File

@ -138,7 +138,7 @@ test_expect_success 'write midx with one v2 pack' '
compare_results_with_midx "one v2 pack"
test_expect_success 'corrupt idx not opened' '
test_expect_success 'corrupt idx reports errors' '
idx=$(test-tool read-midx $objdir | grep "\.idx\$") &&
mv $objdir/pack/$idx backup-$idx &&
test_when_finished "mv backup-\$idx \$objdir/pack/\$idx" &&
@ -149,7 +149,7 @@ test_expect_success 'corrupt idx not opened' '
test_copy_bytes 1064 <backup-$idx >$objdir/pack/$idx &&
git -c core.multiPackIndex=true rev-list --objects --all 2>err &&
test_must_be_empty err
grep "index unavailable" err
'
test_expect_success 'add more objects' '
@ -755,4 +755,30 @@ test_expect_success 'repack --batch-size=<large> repacks everything' '
)
'
test_expect_success 'load reverse index when missing .idx, .pack' '
git init repo &&
test_when_finished "rm -fr repo" &&
(
cd repo &&
git config core.multiPackIndex true &&
test_commit base &&
git repack -ad &&
git multi-pack-index write &&
git rev-parse HEAD >tip &&
pack=$(ls .git/objects/pack/pack-*.pack) &&
idx=$(ls .git/objects/pack/pack-*.idx) &&
mv $idx $idx.bak &&
git cat-file --batch-check="%(objectsize:disk)" <tip &&
mv $idx.bak $idx &&
mv $pack $pack.bak &&
git cat-file --batch-check="%(objectsize:disk)" <tip
)
'
test_done