From e55c5452db0b7cb683d4e2ad51cd8f44046c23bd Mon Sep 17 00:00:00 2001 From: Kristofer Karlsson Date: Mon, 14 Sep 2026 07:57:41 +0200 Subject: [PATCH 1/2] Documentation: describe connectivity checking Add Documentation/technical/connectivity-check.adoc describing the connectivity invariant and the full connectivity check. Signed-off-by: Kristofer Karlsson --- .../technical/connectivity-check.adoc | 109 ++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 Documentation/technical/connectivity-check.adoc diff --git a/Documentation/technical/connectivity-check.adoc b/Documentation/technical/connectivity-check.adoc new file mode 100644 index 00000000000000..d20bff6af64dd2 --- /dev/null +++ b/Documentation/technical/connectivity-check.adoc @@ -0,0 +1,109 @@ +Connectivity checking +===================== + +After receiving new objects via fetch, push (receive-pack), clone, +or bundle, Git verifies that the new reference tips do not leave +the repository in a state where reachable objects are missing. +This verification is called the connectivity check. + +Connectivity invariant +---------------------- + +A repository is connected when every object reachable from its +references is available locally (with exceptions noted below). + +The connectivity check maintains this invariant when references +are updated. It trusts the existing connected state and verifies +that the new reference tips do not introduce references to +unavailable objects. Verification is permitted to stop when it +reaches objects already reachable from trusted existing +references, since their closure is already connected. These +trusted references include local references and references from +alternate object stores. + +Without this check, a truncated or corrupted transfer could leave +a repository in a state where later history walks encounter +missing objects. + +Exceptions +~~~~~~~~~~ + +Gitlink entries (submodule references) are excluded from +connectivity checking. Their target objects belong to a separate +repository. + +In partial clones, objects promised by a promisor remote are +accepted as connected without requiring local existence. The +check excludes promisor objects from traversal so that it does +not trigger on-demand fetches for them. + +Full connectivity check +----------------------- + +`check_connected()` (see `connected.c`) normally performs the +connectivity check using a `rev-list` subprocess, feeding the +new reference tips via stdin. A normal invocation is roughly: + + git rev-list --objects --stdin --not --all --quiet + --alternate-refs [--exclude-promisor-objects] + +When promisor remotes are configured, `check_connected()` first +attempts a fast path based on promisor packfiles. If it falls +back to the `rev-list` check, `--exclude-promisor-objects` is +added so that the traversal does not trigger on-demand fetches. + +Consider the following graph after a fetch, where all reference +tips point directly to commits. For simplicity, only local +references appear on the already-connected side; alternate refs +play the same role. N3 is a merge commit: + + /-------------L2 + / + C1---B1---C2---B2-----L1 + \ \ + N1 N3---T2 + \ / + N2-----------T1 + + L1, L2: local refs + T1, T2: incoming tips (new refs) + N1, N2, N3: incoming commits (N3 is a merge) + B1, B2: boundary commits (already connected) + C1, C2: already connected (but not boundary) + +The incoming set is the commits reachable from the incoming +tips but not from the already-connected side. Boundary commits +are the already-connected commits at the edge of that set. Here +B1 is an ancestor of B2, which happens when incoming branches +fork at different depths in the existing history. + +The check proceeds in three phases: + +1. Walk from the incoming tips (T1, T2) against the trusted + refs (L1, L2) to find the incoming set ({N1, N2, N3, T1, T2}). + +2. Walk the trees of the boundary commits (B1, B2) and mark + those objects uninteresting. These trees are already trusted + because their commits are on the already-connected side. + +3. Walk the trees of each incoming commit and verify that every + referenced object is connected, stopping at objects already + marked uninteresting in phase 2. + +Deepening fetches +~~~~~~~~~~~~~~~~~ + +For deepening fetches (where the shallow boundary moves), the +full check omits `--not --all`. There is no existing-reference +boundary at which the walk can stop. Instead, traversal follows +the effective shallow boundary supplied for the deepened +repository. The new content may be below the old shallow +boundary even when the tips themselves have not changed. + +Non-commit tips +~~~~~~~~~~~~~~~ + +When a new reference points to a non-commit object, such as a +tag, tree, or blob, that object is not part of the commit walk. +These non-commit tips are handled by the subsequent object +traversal. From ebe6c90cc58b9e1f64c9bec4a18e8cb3ce9be1b2 Mon Sep 17 00:00:00 2001 From: Kristofer Karlsson Date: Mon, 14 Sep 2026 07:57:48 +0200 Subject: [PATCH 2/2] connected: add incremental connectivity check via rev-list The full connectivity check uses rev-list to find commits reachable from the incoming tips but not from the already-connected side, then walks their object closure. Commit traversal stops at the connectivity boundary, but trees and blobs reachable from that boundary still need to be walked so they can be marked uninteresting, allocating a struct object for each one. On repositories where the boundary commits have large trees, the connectivity check for small incoming changes visits and tracks more objects than needed. Add an alternative connectivity check that verifies incoming commits incrementally against their parents. The verifier processes incoming commits with ancestors first and compares each new tree against its trusted parent trees. Entries already seen on the trusted side are skipped by OID, so unchanged subtrees need not remain at the same path to be recognized. Changed subtrees are recursively compared against same-path parent subtrees, and new subtrees without a comparison base are verified from scratch. See Documentation/technical/connectivity-check.adoc for the trust invariants and detailed algorithm. The incremental check runs as an internal --verify-trees-incremental mode in rev-list. After the normal revision walk identifies the incoming commits, the verifier consumes them before the usual object traversal; any pending non-commit tips are still handled by the existing traversal. Partial-clone semantics are preserved: objects promised by a promisor remote are accepted as connected, and on-demand fetching is prevented by excluding promisor objects from traversal. The new mode is selected by transfer.connectivityCheck=incremental, with full remaining the default. Deepening fetches fall back to the full check because they do not have the normal existing-reference boundary, and traversal instead follows the effective shallow boundary. p5412 results (median of 3), scaling one dimension at a time. Each fixture is a repository with a flat tree of many directories containing 100 files each. The incoming set is a chain of commits on top of the existing history, with each commit changing files in different directories round-robin. The three axes vary the total repository tree size, the number of incoming commits, and the number of files changed per incoming commit. Scaling tree size (10 incoming commits, 10 files/commit): files full incr. full/incr 5K 0.01s 0.01s 1.0x 50K 0.04s 0.01s 4.0x 200K 0.15s 0.01s 15.0x 800K 0.61s 0.03s 20.3x The full mode must walk the trees of boundary commits, which grows with overall tree size. Incremental still scans the root trees, but avoids descending into unchanged subtrees, so it grows much more slowly with repository size. Scaling incoming commit count (200K files, 10 files/commit): commits full incr. full/incr 1 0.14s 0.01s 14.0x 10 0.15s 0.01s 15.0x 100 0.19s 0.05s 3.8x 500 0.32s 0.27s 1.2x 3000 1.23s 1.52s 0.8x 5000 1.88s 2.43s 0.8x 10000 3.72s 5.36s 0.7x With many commits the per-commit overhead of scanning both the new and parent root trees accumulates and incremental becomes slower. Breakeven is between 500 and 3000 commits and the ratio stabilizes near 0.7x for this fixture. Scaling files per incoming commit (200K files, 10 commits): files/commit full incr. full/incr 1 0.14s 0.01s 14.0x 10 0.15s 0.01s 15.0x 100 0.16s 0.04s 4.0x 500 0.23s 0.14s 1.6x 1000 0.34s 0.28s 1.2x 2000 0.70s 0.63s 1.1x Breakeven is around 1000 files/commit. At 2000 files/commit (every directory touched), incremental remains slightly faster; bypassing the object cache for tree reads likely helps here. For small repositories both modes are fast enough that the difference is difficult to measure reliably. Selected peak RSS measurements from the same fixtures: case full incr. ratio 200K files, 10 commits 31 MB 12 MB 0.4x 800K files, 10 commits 110 MB 26 MB 0.2x 200K files, 5000 commits 155 MB 151 MB 1.0x Incremental uses substantially less memory when it can prune most of the boundary tree walk. In the long-history case the two modes visit similar object sets and memory converges. The regression cases in the CPU benchmarks are in wall-clock time rather than memory, primarily from scanning some trees more than once. Signed-off-by: Kristofer Karlsson --- Documentation/config/transfer.adoc | 20 + Documentation/rev-list-options.adoc | 6 + .../technical/connectivity-check.adoc | 134 ++++ Makefile | 1 + builtin/rev-list.c | 18 + connected.c | 24 + meson.build | 1 + t/meson.build | 1 + ...enerate-repo-p5412-connectivity-check.perl | 44 ++ t/perf/p5412-connectivity-check.sh | 92 +++ t/t5412-connectivity-check.sh | 655 ++++++++++++++++++ tree-verify.c | 306 ++++++++ tree-verify.h | 15 + 13 files changed, 1317 insertions(+) create mode 100644 t/perf/generate-repo-p5412-connectivity-check.perl create mode 100755 t/perf/p5412-connectivity-check.sh create mode 100755 t/t5412-connectivity-check.sh create mode 100644 tree-verify.c create mode 100644 tree-verify.h diff --git a/Documentation/config/transfer.adoc b/Documentation/config/transfer.adoc index f1ce50f4a6e6ba..b9939d3bde841c 100644 --- a/Documentation/config/transfer.adoc +++ b/Documentation/config/transfer.adoc @@ -1,3 +1,23 @@ +transfer.connectivityCheck:: + Choose which algorithm to use for the connectivity check + performed during object transfer operations such as + linkgit:git-fetch[1] and linkgit:git-receive-pack[1]. + The connectivity check verifies that all objects reachable + from the incoming tips are available locally or, in a partial + clone, promised by a promisor remote. + The variants are as follows: ++ +-- +`full` (default);; + Walk the full object closure of the boundary commits. +`incremental`;; + Verify incoming commits by diffing their trees against parent + trees, recursively descending only into entries that differ. + The largest benefits occur when incoming commits change a + small fraction of a large tree closure. + Falls back to `full` for deepening fetches. +-- + transfer.credentialsInUrl:: A configured URL can contain plaintext credentials in the form `://:@/`. You may want diff --git a/Documentation/rev-list-options.adoc b/Documentation/rev-list-options.adoc index fd831f0ec64744..7964b691c4af79 100644 --- a/Documentation/rev-list-options.adoc +++ b/Documentation/rev-list-options.adoc @@ -1089,6 +1089,12 @@ we cannot get their Object ID though, an error will be raised. stronger than `--missing=allow-promisor` because it limits the traversal, rather than just silencing errors about missing objects. + +`--verify-trees-incremental`:: + (For internal use only.) Verify tree connectivity + incrementally by comparing each commit's tree against its + parent trees. Used by `check_connected()` when + `transfer.connectivityCheck` is set to `incremental`. endif::git-rev-list[] `--no-walk[=(sorted|unsorted)]`:: diff --git a/Documentation/technical/connectivity-check.adoc b/Documentation/technical/connectivity-check.adoc index d20bff6af64dd2..0a8f370546be2f 100644 --- a/Documentation/technical/connectivity-check.adoc +++ b/Documentation/technical/connectivity-check.adoc @@ -107,3 +107,137 @@ When a new reference points to a non-commit object, such as a tag, tree, or blob, that object is not part of the commit walk. These non-commit tips are handled by the subsequent object traversal. + +Incremental connectivity check +------------------------------ + +The incremental mode, selected by +`transfer.connectivityCheck=incremental`, avoids traversing the +full tree walk of the boundary commits. Instead, it verifies +each incoming commit's tree against the already-trusted trees of +its parents. + +Trust model +~~~~~~~~~~~ + +A tree is trusted when its transitive object closure is known to +be connected. Trees reachable from commits on the +already-connected side of the boundary are therefore trusted. + +Incoming commits are processed with ancestors before descendants. +Once an incoming commit's tree has been verified, it is trusted +and can be used as a comparison base for later descendants. + +This gives an inductive correctness argument: every parent of the +commit currently being verified is either already connected or is +an earlier incoming commit whose tree has already been verified. + +Tree states +~~~~~~~~~~~ + +The verifier tracks tree OIDs in three states: + +untrusted:: + The tree has not yet been established as connected. This + is the implicit state of an OID not present in the state + map. + +trusted:: + The tree is known to have a connected transitive closure, + but its direct entries have not yet been published into the + verifier's trusted object sets. + +expanded:: + The tree is trusted and its direct non-gitlink entries + have also been published into the trusted object sets. + +State transitions are monotonic: a tree may move from untrusted +to trusted to expanded, but never backwards. An untrusted tree +that is successfully verified goes directly to expanded. + +Blobs require only trusted/untrusted state: a blob becomes +trusted when it is found in a trusted tree or when its existence +and type have been verified directly. + +The trusted/expanded distinction is an optimization. An expanded +parent does not need to be reread merely to publish entries that +are already trusted, though it may still be read when same-path +subtree bases are needed for recursive comparison. + +Algorithm +~~~~~~~~~ + +At a high level: + + verify(commits): + sort topologically (ancestors first) + for each commit: + mark parent root trees as trusted + verify_tree(commit.tree, parent root trees) + + verify_tree(tree, base_trees): + if tree already trusted: return + read tree, collect entries not already trusted + for each available base tree: + publish its entries as trusted + record same-path subtrees as bases + for each collected entry: + if now trusted: skip + if blob: verify blob connectivity and type + if tree: verify_tree(entry, its recorded bases) + mark tree as expanded + +The important ordering within `verify_tree` is that entries from +the new tree are collected before the base trees are scanned, but +are processed only afterwards. Trust learned from any base can +therefore eliminate work before recursive verification begins. + +Same-path parent subtrees are passed down as comparison bases +during recursive descent. If no comparison base is available, +the new subtree is verified from scratch. + +Worked example +~~~~~~~~~~~~~~ + +Consider a commit that changes one file under `lib/` and moves an +unchanged subtree from `src/` to `dev/`: + + Parent tree New tree + +-- src/ (aaa) +-- dev/ (aaa) + +-- lib/ (bbb) +-- lib/ (ccc) + +-- foo.c (ddd) +-- foo.c (ddd) + +-- bar.c (eee) +-- bar.c (fff) + +Scanning the parent makes `aaa` trusted even though it moved from +`src/` to `dev/`, so that subtree is skipped. The changed `ccc` +subtree is compared against its same-path parent `bbb`; scanning +`bbb` makes `ddd` and `eee` trusted, leaving only the new `fff` +blob to be checked. + +This illustrates two properties: + +* Trust is OID-based rather than path-based. An unchanged subtree + is recognized after a move. + +* Same-path parent subtrees provide recursive comparison bases. + These bases improve pruning efficiency but are not required for + correctness; a new subtree can always be verified from scratch. + +Multiple parents +~~~~~~~~~~~~~~~~ + +For a merge commit, root trees from all parents are comparison +bases. When several parents contain a same-path subtree, each +matching subtree is collected as a recursive comparison base. + +Entries published from any trusted parent become globally trusted, +so a matching tree or blob entry present in any parent can be +skipped while verifying the merge tree. + +Missing comparison bases +~~~~~~~~~~~~~~~~~~~~~~~~ + +A promised base tree may not be locally available for comparison. +In that case the verifier skips that base and verifies the new +subtree without it. The missing comparison can reduce pruning but +does not affect correctness. diff --git a/Makefile b/Makefile index d4b775953d3842..aa5b4e2b849fb6 100644 --- a/Makefile +++ b/Makefile @@ -1357,6 +1357,7 @@ LIB_OBJS += trailer.o LIB_OBJS += transport-helper.o LIB_OBJS += transport.o LIB_OBJS += tree-diff.o +LIB_OBJS += tree-verify.o LIB_OBJS += tree-walk.o LIB_OBJS += tree.o LIB_OBJS += unpack-trees.o diff --git a/builtin/rev-list.c b/builtin/rev-list.c index 6b596231ab1ab0..7741fdec9f9b58 100644 --- a/builtin/rev-list.c +++ b/builtin/rev-list.c @@ -28,6 +28,7 @@ #include "commit-reach.h" #include "quote.h" #include "strbuf.h" +#include "tree-verify.h" struct rev_list_info { struct rev_info *revs; @@ -706,6 +707,7 @@ int cmd_rev_list(int argc, int bisect_find_all = 0; int use_bitmap_index = 0; int filter_provided_objects = 0; + int verify_trees_incremental = 0; const char *show_progress = NULL; int ret = 0; @@ -748,6 +750,8 @@ int cmd_rev_list(int argc, if (!strcmp(arg, "--exclude-promisor-objects")) { repo->fetch_if_missing = 0; revs.exclude_promisor_objects = 1; + } else if (!strcmp(arg, "--verify-trees-incremental")) { + verify_trees_incremental = 1; } else if (skip_prefix(arg, "--missing=", &arg)) { parse_missing_action_value(repo, arg); } else if (!strcmp(arg, "-z")) { @@ -822,6 +826,8 @@ int cmd_rev_list(int argc, if (!strcmp(arg, "--exclude-promisor-objects")) continue; /* already handled above */ + if (!strcmp(arg, "--verify-trees-incremental")) + continue; /* already handled above */ if (skip_prefix(arg, "--missing=", &arg)) continue; /* already handled above */ @@ -935,6 +941,18 @@ int cmd_rev_list(int argc, prepare_maximal_independent(&revs); + if (verify_trees_incremental) { + struct commit *commit; + struct commit_list *new_commits = NULL; + + while ((commit = get_revision(&revs)) != NULL) + commit_list_insert(commit, &new_commits); + + verify_commits_incremental(repo, &new_commits, + revs.exclude_promisor_objects); + commit_list_free(new_commits); + } + if (revs.tree_objects) mark_edges_uninteresting(&revs, show_edge, 0); diff --git a/connected.c b/connected.c index 929b9bd28d6fab..e3dcd8e2b0ff58 100644 --- a/connected.c +++ b/connected.c @@ -1,6 +1,7 @@ #define USE_THE_REPOSITORY_VARIABLE #include "git-compat-util.h" +#include "config.h" #include "gettext.h" #include "hex.h" #include "odb.h" @@ -67,6 +68,26 @@ static int check_connected_promisor(oid_iterate_fn fn, return 1; } +static int incremental_check_applicable(struct check_connected_options *opt) +{ + const char *algorithm = NULL; + + if (repo_config_get_string_tmp(the_repository, + "transfer.connectivitycheck", + &algorithm)) + return 0; + if (!strcasecmp(algorithm, "full")) + return 0; + if (strcasecmp(algorithm, "incremental")) + die(_("unknown transfer.connectivityCheck algorithm '%s'"), + algorithm); + + if (opt->is_deepening_fetch) + return 0; + + return 1; +} + /* * If we feed all the commits we want to verify to this command * @@ -133,6 +154,9 @@ int check_connected(oid_iterate_fn fn, void *cb_data, if (opt->progress) strvec_pushf(&rev_list.args, "--progress=%s", _("Checking connectivity")); + if (incremental_check_applicable(opt)) + strvec_push(&rev_list.args, + "--verify-trees-incremental"); rev_list.git_cmd = 1; if (opt->env) diff --git a/meson.build b/meson.build index 0a95d90d211fd6..d94dedc26cc0c6 100644 --- a/meson.build +++ b/meson.build @@ -562,6 +562,7 @@ libgit_sources = [ 'transport-helper.c', 'transport.c', 'tree-diff.c', + 'tree-verify.c', 'tree-walk.c', 'tree.c', 'unpack-trees.c', diff --git a/t/meson.build b/t/meson.build index 7f53cca7d1f891..19a8246c44fc49 100644 --- a/t/meson.build +++ b/t/meson.build @@ -652,6 +652,7 @@ integration_tests = [ 't5409-colorize-remote-messages.sh', 't5410-receive-pack.sh', 't5411-proc-receive-hook.sh', + 't5412-connectivity-check.sh', 't5500-fetch-pack.sh', 't5501-fetch-push-alternates.sh', 't5502-quickfetch.sh', diff --git a/t/perf/generate-repo-p5412-connectivity-check.perl b/t/perf/generate-repo-p5412-connectivity-check.perl new file mode 100644 index 00000000000000..95469962804db9 --- /dev/null +++ b/t/perf/generate-repo-p5412-connectivity-check.perl @@ -0,0 +1,44 @@ +#!/usr/bin/perl +# +# Generate a fast-import stream for p5412 connectivity check benchmarks. +# +# Usage: generate-repo-p5412-connectivity-check.perl +# [] [] +# +# Creates one initial commit with dirs*files_per_dir files, then +# additional commits each modifying +# files in directories chosen round-robin from 1... + +use strict; +use warnings; + +my ($nd, $nf, $nc, $hot, $fpc) = @ARGV; +$hot = $nd if !$hot || $hot > $nd; +$fpc = 1 if !$fpc; + +sub data { + printf "data %d\n%s\n", length($_[0]), $_[0]; +} + +# Initial tree: one commit with nd*nf files. +printf "commit refs/heads/main\n"; +printf "committer perf now\n"; +data("initial"); +for my $d (1..$nd) { + for my $f (1..$nf) { + printf "M 100644 inline d-%04d/f-%03d\n", $d, $f; + data(sprintf "%03d%03d", $d, $f); + } +} + +# Subsequent commits (auto-chained by fast-import). +for my $i (1..$nc) { + printf "commit refs/heads/main\n"; + printf "committer perf now\n"; + data(sprintf "change-%03d", $i); + for my $j (0..$fpc-1) { + my $d = (($i + $j) % $hot) + 1; + printf "M 100644 inline d-%04d/f-001\n", $d; + data(sprintf "c%d-%d", $i, $j); + } +} diff --git a/t/perf/p5412-connectivity-check.sh b/t/perf/p5412-connectivity-check.sh new file mode 100755 index 00000000000000..827643a847f511 --- /dev/null +++ b/t/perf/p5412-connectivity-check.sh @@ -0,0 +1,92 @@ +#!/bin/sh + +test_description='performance of connectivity check modes + +Compare the default and incremental rev-list connectivity modes +directly, avoiding pack transfer noise. + +Each repository has a flat tree of many directories with 100 files +in each. Three axes are scaled independently: tree size, commit +count, and files changed per commit.' + +. ./perf-lib.sh + +test_perf_fresh_repo + +generate="$TEST_DIRECTORY/perf/generate-repo-p5412-connectivity-check.perl" + +# $1=dirs $2=files_per_dir $3=commits $4=hot_dirs (optional, default=all) +# $5=files_per_commit (optional, default=1) +test_perf_conn () { + local nd="$1" nf="$2" nc="$3" hot="${4:-$1}" fpc="${5:-1}" + local total=$(($nd * $nf)) + local name="repo-${nd}d-${nf}f-${nc}c-${hot}h-${fpc}fpc" + local label="${total} files, ${nc} commits" + if test "$hot" -lt "$nd" + then + label="$label (${hot} hot dirs)" + fi + if test "$fpc" -gt 1 + then + label="$label (${fpc} files/commit)" + fi + + test_expect_success "setup $label" ' + if test -d '"$name"' + then + true + else + git init '"$name"' && + "$PERL_PATH" '"$generate"' '"$nd"' '"$nf"' '"$nc"' '"$hot"' '"$fpc"' | + git -C '"$name"' fast-import --date-format=now --quiet && + ( + cd '"$name"' && + git rev-parse main~'"$nc"' >../'"${name}"'_old && + git rev-parse main >../'"${name}"'_new && + git update-ref refs/heads/main \ + $(cat ../'"${name}"'_old) && + git repack -ad && + git config gc.auto 0 + ) + fi + ' + + test_perf "$label (full)" ' + cat '"${name}"'_new | + git -C '"$name"' rev-list \ + --objects --stdin --not --all --quiet \ + --exclude-promisor-objects + ' + + test_perf "$label (incremental)" ' + cat '"${name}"'_new | + git -C '"$name"' rev-list --verify-trees-incremental \ + --objects --stdin --not --all --quiet \ + --exclude-promisor-objects + ' +} + +# Scaling tree size (10 commits, 10 files/commit). +test_perf_conn 50 100 10 50 10 +test_perf_conn 500 100 10 500 10 +test_perf_conn 2000 100 10 2000 10 +test_perf_conn 8000 100 10 8000 10 + +# Scaling commit count (200K files, 10 files/commit). +test_perf_conn 2000 100 1 2000 10 +test_perf_conn 2000 100 10 2000 10 +test_perf_conn 2000 100 100 2000 10 +test_perf_conn 2000 100 500 2000 10 +test_perf_conn 2000 100 3000 2000 10 +test_perf_conn 2000 100 5000 2000 10 +test_perf_conn 2000 100 10000 2000 10 + +# Scaling files per commit (200K files, 10 commits). +test_perf_conn 2000 100 10 2000 1 +test_perf_conn 2000 100 10 2000 10 +test_perf_conn 2000 100 10 2000 100 +test_perf_conn 2000 100 10 2000 500 +test_perf_conn 2000 100 10 2000 1000 +test_perf_conn 2000 100 10 2000 2000 + +test_done diff --git a/t/t5412-connectivity-check.sh b/t/t5412-connectivity-check.sh new file mode 100755 index 00000000000000..e276085e83635d --- /dev/null +++ b/t/t5412-connectivity-check.sh @@ -0,0 +1,655 @@ +#!/bin/sh + +test_description='connectivity check (transfer.connectivityCheck)' +GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main +export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME + +. ./test-lib.sh + +test_oid_cache <<-\EOF +missing sha1:0000000000000000000000000000000000000001 +missing sha256:0000000000000000000000000000000000000000000000000000000000000001 +EOF + +set_connectivity_check () { + git -C "$1" config transfer.connectivityCheck "$2" +} + +# Run a connectivity check via rev-list directly. Uses $mode +# (set by the enclosing for-loop) to choose full or incremental. +check_connected () { + flags= && + if test "$mode" = incremental + then + flags=--verify-trees-incremental + fi && + printf '%s\n' "$@" | + git rev-list $flags \ + --objects --stdin --not --all --quiet \ + --exclude-promisor-objects +} + +# Run git with a temporary index, leaving the real index untouched. +tmpgit () { + GIT_INDEX_FILE=.git/tmp-idx git "$@" +} + +# Create a commit with one file changed, without modifying HEAD, +# index, or worktree. Prints the new commit OID on stdout. +# Usage: commit_with_change +commit_with_change () { + new_blob=$(echo "$3" | git hash-object -w --stdin) && + tmpgit read-tree "$1" && + tmpgit update-index --replace \ + --cacheinfo "100644,$new_blob,$2" && + new_tree=$(tmpgit write-tree) && + rm -f .git/tmp-idx && + git commit-tree "$new_tree" -p "$1" -m "modify $2" +} + +# Check OIDs and optionally verify trace2 counts. +# Usage: check_connected_trace ... +# An empty string for or skips that assertion. +check_connected_trace () { + trace_file=$1 trees=$2 blobs=$3 && + shift 3 && + test_env GIT_TRACE2_EVENT="$(pwd)/$trace_file" \ + check_connected "$@" && + if test "$mode" != incremental + then + return + fi && + if test -n "$trees" + then + test_trace2_data_singular connectivity trees_loaded "$trees" \ + <"$trace_file" + fi && + if test -n "$blobs" + then + test_trace2_data_singular connectivity blobs_checked "$blobs" \ + <"$trace_file" + fi +} + +# Shared setup: a repo with several root-level files and nested dirs. +# The unchanged/ subtree (10 dirs x 10 files = 100 blobs, 11 trees) +# acts as a canary: any test asserting small tree/blob counts would +# fail dramatically if incremental accidentally walked into it. + +test_expect_success 'setup main repo' ' + git init main-repo && + ( + cd main-repo && + for i in $(test_seq 1 5) + do + echo "file $i" >"file-$i.txt" || return 1 + done && + git add file-*.txt && + git commit -m "initial" && + + mkdir -p a/b/c && + echo deep >a/b/c/deep.txt && + echo other >a/other.txt && + git add a/b/c/deep.txt a/other.txt && + git commit -m "add nested dirs" && + + for i in $(test_seq 1 10) + do + d="unchanged/dir-$i" && + mkdir -p "$d" && + for j in $(test_seq 1 10) + do + echo "$i $j" >"$d/file-$j.txt" || return 1 + done + done && + git add unchanged/ && + git commit -m "add unchanged canary subtree" + ) +' + +test_expect_success 'setup replacement object repo' ' + git init replace-test && + ( + cd replace-test && + + test_commit --no-tag original file.txt && + original=$(git rev-parse HEAD) && + orig_blob=$(git rev-parse HEAD:file.txt) && + + # Orphan replacement commit with a different tree + replacement_tree=$(echo replaced | git hash-object -w --stdin | + xargs -I{} git mktree <<-EOF + 100644 blob {} file.txt + EOF + ) && + replacement=$(git commit-tree -m "replacement" \ + "$replacement_tree") && + + git replace "$original" "$replacement" && + + # Remove the original blob so only the replacement + # tree is complete. + rm .git/objects/$(test_oid_to_path "$orig_blob") && + + # Drop branch and HEAD so --not --all does not + # exclude the original commit. + git update-ref -d refs/heads/main && + git update-ref -d HEAD && + + echo "$original" >.git/test-oid + ) +' + +missing_oid=$(test_oid missing) +original_oid=$(cat replace-test/.git/test-oid) + +for mode in full incremental +do + +# Corruption detection: craft broken object graphs and verify detection. +# All tests use main-repo without modifying its refs or worktree. + +test_expect_success "$mode: rejects commit with missing blob" ' + ( + cd main-repo && + bad_tree=$(printf "100644 blob ${missing_oid}\tfile.txt\n" | + git mktree --missing) && + bad_commit=$(git commit-tree "$bad_tree" -p HEAD -m "bad") && + test_expect_code 128 check_connected "$bad_commit" 2>err && + test_grep "missing blob object" err + ) +' + +test_expect_success "$mode: rejects commit with missing subtree" ' + ( + cd main-repo && + bad_tree=$(printf "40000 tree ${missing_oid}\tdir\n" | + git mktree --missing) && + bad_commit=$(git commit-tree "$bad_tree" -p HEAD -m "bad") && + test_expect_code 128 check_connected "$bad_commit" 2>err && + test_grep "bad tree object" err + ) +' + +test_expect_success "$mode: verifies direct tree tip" ' + ( + cd main-repo && + bad_tree=$(printf "100644 blob ${missing_oid}\tfile.txt\n" | + git mktree --missing) && + test_expect_code 128 check_connected "$bad_tree" 2>err && + test_grep "missing blob object" err + ) +' + +test_expect_success "$mode: verifies direct blob tip" ' + ( + cd main-repo && + blob_oid=$(echo "hello" | git hash-object -w --stdin) && + check_connected "$blob_oid" + ) +' + +test_expect_success "$mode: rejects missing direct blob tip" ' + ( + cd main-repo && + test_expect_code 128 check_connected \ + "$missing_oid" 2>err + ) +' + +test_expect_success PERL_TEST_HELPERS \ + "$mode: rejects blob OID reused as tree entry" ' + ( + cd main-repo && + + blob_oid=$(git rev-parse HEAD:file-1.txt) && + bin_oid=$(echo "$blob_oid" | hex2oct) && + + bad_tree=$(printf "40000 subdir\0$bin_oid" | + git hash-object -t tree -w --stdin) && + bad_commit=$(git commit-tree -p HEAD -m "child" "$bad_tree") && + + test_expect_code 128 check_connected "$bad_commit" 2>err && + test_grep "not a tree" err + ) +' + +test_expect_success PERL_TEST_HELPERS \ + "$mode: rejects tree OID reused as blob entry" ' + ( + cd main-repo && + + tree_oid=$(git rev-parse HEAD:a) && + bin_oid=$(echo "$tree_oid" | hex2oct) && + + bad_tree=$(printf "100644 fakefile\0$bin_oid" | + git hash-object -t tree -w --stdin) && + bad_commit=$(git commit-tree -p HEAD -m "child" "$bad_tree") && + + test_expect_code 128 check_connected "$bad_commit" 2>err && + test_grep "not a blob" err + ) +' + +test_expect_success "$mode: checks multiple tips" ' + ( + cd main-repo && + c1=$(commit_with_change HEAD file-1.txt "tip-a") && + c2=$(commit_with_change HEAD file-2.txt "tip-b") && + git tag -a -m "tagged" multi-tag "$c1" && + tag_oid=$(git rev-parse multi-tag) && + git tag -d multi-tag && + check_connected "$c2" "$tag_oid" + ) +' + +# Tree-diff optimization: verify trace2 counts. + +test_expect_success "$mode: handles root commit (no parents)" ' + ( + cd main-repo && + blob_oid=$(echo "root-content" | git hash-object -w --stdin) && + tree_oid=$(printf "100644 blob %s\tfile.txt\n" \ + "$blob_oid" | git mktree) && + root_oid=$(git commit-tree "$tree_oid" -m "root") && + + # No parent trees, so the full tree is verified. + # 1 tree loaded (root), 1 blob checked. + check_connected_trace trace-root.txt 1 1 "$root_oid" + ) +' + +test_expect_success "$mode: handles single file change" ' + ( + cd main-repo && + oid=$(commit_with_change HEAD file-1.txt "changed") && + + # 2 trees loaded (new root + parent root), 1 blob checked. + check_connected_trace trace-flat.txt 2 1 "$oid" + ) +' + +test_expect_success "$mode: handles nested change" ' + ( + cd main-repo && + oid=$(commit_with_change HEAD a/b/c/deep.txt "deep-changed") && + # 4 new trees + 4 parent trees = 8 loaded, 1 blob checked. + check_connected_trace trace-nested.txt 8 1 "$oid" + ) +' + +test_expect_success "$mode: handles change-then-revert" ' + ( + cd main-repo && + c1=$(commit_with_change HEAD file-1.txt "revert-tmp") && + c2=$(commit_with_change "$c1" file-1.txt "file 1") && + c3=$(commit_with_change "$c2" file-1.txt "revert-final") && + + # c1: new root + parent root = 2 loads. c2: root matches + # HEAD (already trusted), skipped. c3: new root + parent + # already expanded = 1 load. Total: 3 trees, 2 blobs. + check_connected_trace trace-revert.txt 3 2 "$c3" + ) +' + +test_expect_success "$mode: handles subtree moved to another path" ' + ( + cd main-repo && + moved_tree=$(git ls-tree HEAD | + sed "s/ a$/ moved/" | + git mktree) && + moved=$(git commit-tree "$moved_tree" -p HEAD -m move) && + # New root + parent root scanned, but the moved subtree + # (same OID) is trusted and not descended into. + check_connected_trace trace-move.txt 2 0 "$moved" + ) +' + +test_expect_success "$mode: handles multi-parent merge" ' + ( + cd main-repo && + left=$(commit_with_change HEAD file-1.txt left) && + right=$(commit_with_change HEAD file-2.txt right) && + git update-ref refs/heads/left "$left" && + git update-ref refs/heads/right "$right" && + left_blob=$(git rev-parse "$left:file-1.txt") && + right_blob=$(git rev-parse "$right:file-2.txt") && + tmpgit read-tree HEAD && + tmpgit update-index --replace \ + --cacheinfo "100644,$left_blob,file-1.txt" && + tmpgit update-index --replace \ + --cacheinfo "100644,$right_blob,file-2.txt" && + merge_tree=$(tmpgit write-tree) && + rm -f .git/tmp-idx && + merge=$(git commit-tree "$merge_tree" \ + -p "$left" -p "$right" -m merge) && + # Both parent root trees are scanned as bases, so + # blobs from each parent are trusted without ODB checks. + check_connected_trace trace-merge.txt 3 0 "$merge" && + git update-ref -d refs/heads/left && + git update-ref -d refs/heads/right + ) +' + +test_expect_success "$mode: handles merge with incoming and boundary parents" ' + ( + cd main-repo && + # parent1 is incoming (not a ref), HEAD is boundary. + parent1=$(commit_with_change HEAD file-1.txt merge-inc) && + merge=$(git commit-tree \ + "$(git rev-parse "$parent1^{tree}")" \ + -p "$parent1" -p HEAD -m merge-mixed) && + # parent1 verified first (topo order): 2 trees, 1 blob. + # merge tree = parent1 tree (already trusted): 0 extra. + check_connected_trace trace-merge-inc.txt 2 1 "$merge" + ) +' + +test_expect_success "$mode: handles gitlink entries (submodules)" ' + ( + cd main-repo && + tmpgit read-tree HEAD && + tmpgit update-index --add \ + --cacheinfo "160000,$missing_oid,my-submodule" && + gitlink_tree=$(tmpgit write-tree) && + rm -f .git/tmp-idx && + gitlink_commit=$(git commit-tree "$gitlink_tree" -p HEAD \ + -m "add gitlink") && + + # Gitlink entries are skipped -- the missing submodule + # commit OID does not cause a failure. + check_connected_trace trace-gitlink.txt 2 0 "$gitlink_commit" + ) +' + +test_expect_success "$mode: handles file-to-directory transition" ' + ( + cd main-repo && + + # Parent: "foo" is a blob at root. + blob_a=$(echo "file-content" | git hash-object -w --stdin) && + tmpgit read-tree HEAD && + tmpgit update-index --add \ + --cacheinfo "100644,$blob_a,foo" && + parent_tree=$(tmpgit write-tree) && + rm -f .git/tmp-idx && + parent=$(git commit-tree "$parent_tree" -p HEAD \ + -m "add foo as file") && + + # Child: "foo" becomes a directory (foo/bar.txt). + blob_b=$(echo "dir-content" | git hash-object -w --stdin) && + tmpgit read-tree "$parent" && + tmpgit update-index --remove foo && + tmpgit update-index --add \ + --cacheinfo "100644,$blob_b,foo/bar.txt" && + child_tree=$(tmpgit write-tree) && + rm -f .git/tmp-idx && + child=$(git commit-tree "$child_tree" -p "$parent" \ + -m "foo: file to directory") && + check_connected_trace trace-f2d.txt "" "" "$child" + ) +' + +test_expect_success "$mode: handles directory-to-file transition" ' + ( + cd main-repo && + + # Parent: "bar/baz.txt" exists (bar is a directory). + blob_a=$(echo "nested" | git hash-object -w --stdin) && + tmpgit read-tree HEAD && + tmpgit update-index --add \ + --cacheinfo "100644,$blob_a,bar/baz.txt" && + parent_tree=$(tmpgit write-tree) && + rm -f .git/tmp-idx && + parent=$(git commit-tree "$parent_tree" -p HEAD \ + -m "add bar as directory") && + + # Child: "bar" becomes a plain file. + blob_b=$(echo "flat" | git hash-object -w --stdin) && + tmpgit read-tree "$parent" && + tmpgit update-index --remove bar/baz.txt && + tmpgit update-index --add \ + --cacheinfo "100644,$blob_b,bar" && + child_tree=$(tmpgit write-tree) && + rm -f .git/tmp-idx && + child=$(git commit-tree "$child_tree" -p "$parent" \ + -m "bar: directory to file") && + check_connected_trace trace-d2f.txt "" "" "$child" + ) +' + +# Replacement objects. + +test_expect_success "$mode: accepts with replacement objects" ' + ( + cd replace-test && + check_connected "$original_oid" + ) +' + +test_expect_success "$mode: rejects without replacement objects" ' + ( + cd replace-test && + GIT_NO_REPLACE_OBJECTS=1 && + export GIT_NO_REPLACE_OBJECTS && + test_expect_code 128 check_connected \ + "$original_oid" 2>err && + test_grep "missing blob object" err + ) +' + +test_expect_success "$mode: accepts missing promised blob" ' + test_when_finished "rm -rf prom-src prom-server.git prom-client" && + git init prom-src && + test_commit -C prom-src --no-tag base file.txt original && + test_commit -C prom-src --no-tag "add file2" file2.txt extra && + git clone --bare prom-src prom-server.git && + git -C prom-server.git config uploadpack.allowfilter true && + git -C prom-server.git config uploadpack.allowanysha1inwant true && + git clone --no-checkout --filter=blob:none \ + "file://$(pwd)/prom-server.git" prom-client && + ( + cd prom-client && + promised_blob=$(git rev-parse HEAD:file2.txt) && + test_must_fail env GIT_NO_LAZY_FETCH=1 \ + git cat-file -e "$promised_blob" && + new_tree=$(printf "100644 blob %s\tnewname.txt\n" \ + "$promised_blob" | + git mktree --missing) && + new_commit=$(git commit-tree "$new_tree" \ + -p HEAD -m "reuse promised blob") && + check_connected "$new_commit" && + test_must_fail env GIT_NO_LAZY_FETCH=1 \ + git cat-file -e "$promised_blob" + ) +' + +test_expect_success "$mode: accepts missing promised tree" ' + test_when_finished "rm -rf prom-tree-src prom-tree-server.git prom-tree-client" && + git init prom-tree-src && + mkdir -p prom-tree-src/a/b && + test_commit -C prom-tree-src --no-tag "nested dirs" a/b/file.txt deep && + git clone --bare prom-tree-src prom-tree-server.git && + git -C prom-tree-server.git config uploadpack.allowfilter true && + git -C prom-tree-server.git config uploadpack.allowanysha1inwant true && + git clone --no-checkout --filter=tree:1 \ + "file://$(pwd)/prom-tree-server.git" prom-tree-client && + ( + cd prom-tree-client && + promised_tree=$(git ls-tree HEAD -- a | + awk "{print \$3}") && + test_must_fail env GIT_NO_LAZY_FETCH=1 \ + git cat-file -e "$promised_tree" && + new_tree=$(printf "40000 tree %s\trenamed\n" \ + "$promised_tree" | + git mktree --missing) && + new_commit=$(git commit-tree "$new_tree" \ + -p HEAD -m "reuse promised tree") && + check_connected "$new_commit" && + test_must_fail env GIT_NO_LAZY_FETCH=1 \ + git cat-file -e "$promised_tree" + ) +' + +test_expect_success "$mode: verifies new subtree when parent subtree is promised" ' + test_when_finished "rm -rf prom-base-src prom-base-server.git prom-base-client" && + git init prom-base-src && + mkdir -p prom-base-src/a && + test_commit -C prom-base-src --no-tag "base" a/file.txt deep && + git clone --bare prom-base-src prom-base-server.git && + git -C prom-base-server.git config uploadpack.allowfilter true && + git -C prom-base-server.git config uploadpack.allowanysha1inwant true && + git clone --no-checkout --filter=tree:1 \ + "file://$(pwd)/prom-base-server.git" prom-base-client && + ( + cd prom-base-client && + parent_subtree=$(git ls-tree HEAD -- a | + awk "{print \$3}") && + test_must_fail env GIT_NO_LAZY_FETCH=1 \ + git cat-file -e "$parent_subtree" && + new_blob=$(echo "local-content" | git hash-object -w --stdin) && + new_subtree=$(printf "100644 blob %s\tfile.txt\n" \ + "$new_blob" | git mktree) && + new_root=$(printf "40000 tree %s\ta\n" \ + "$new_subtree" | git mktree) && + new_commit=$(git commit-tree "$new_root" \ + -p HEAD -m "replace promised subtree") && + check_connected "$new_commit" && + test_must_fail env GIT_NO_LAZY_FETCH=1 \ + git cat-file -e "$parent_subtree" + ) +' + +test_expect_success "$mode: verifies local commit in partial clone" ' + test_when_finished "rm -rf pc-src pc-server.git pc-client" && + git init pc-src && + test_commit -C pc-src --no-tag base file.txt && + git clone --bare pc-src pc-server.git && + git -C pc-server.git config uploadpack.allowfilter true && + git -C pc-server.git config uploadpack.allowanysha1inwant true && + git clone --filter=blob:none \ + "file://$(pwd)/pc-server.git" pc-client && + ( + cd pc-client && + local_commit=$(commit_with_change HEAD file.txt local-content) && + check_connected "$local_commit" + ) +' + +test_expect_success "$mode: respects shallow boundary" ' + test_when_finished "rm -rf shallow-src shallow" && + git init shallow-src && + test_commit -C shallow-src --no-tag base file content-1 && + mkdir shallow-src/sub && + test_commit -C shallow-src --no-tag change sub/other content-2 && + git clone --depth=1 "file://$(pwd)/shallow-src" shallow && + ( + cd shallow && + tip=$(git rev-parse HEAD) && + git for-each-ref --format="delete %(refname)" | + git update-ref --no-deref --stdin && + check_connected "$tip" + ) +' + +test_expect_success "$mode: deepening fetch succeeds" ' + test_when_finished "rm -rf deepen-src deepen-server.git deepen-client" && + git init deepen-src && + test_commit -C deepen-src --no-tag c1 file.txt && + test_commit -C deepen-src --no-tag c2 file.txt && + test_commit -C deepen-src --no-tag c3 file.txt && + git clone --bare deepen-src deepen-server.git && + git clone --depth=1 "file://$(pwd)/deepen-server.git" deepen-client && + set_connectivity_check deepen-client $mode && + test -f deepen-client/.git/shallow && + GIT_TRACE2_EVENT="$(pwd)/deepen-trace.txt" \ + git -C deepen-client fetch --deepen=2 origin main && + # Incremental falls back to full for deepening fetches, + # so the trees_loaded event should not appear. + test_grep ! trees_loaded deepen-trace.txt +' + +test_expect_success "$mode: malformed tree detected" ' + ( + cd main-repo && + echo abc >malformed-tree && + malformed_tree=$(git hash-object --literally -t tree -w \ + malformed-tree) && + malformed_commit=$(git commit-tree "$malformed_tree" \ + -p HEAD -m malformed) && + test_expect_code 128 check_connected \ + "$malformed_commit" 2>err + ) +' + +test_expect_success PERL_TEST_HELPERS \ + "$mode: mid-tree corruption detected" ' + ( + cd main-repo && + # Build a tree with one valid entry followed by garbage. + blob_oid=$(echo "valid" | git hash-object -w --stdin) && + bin_oid=$(echo "$blob_oid" | hex2oct) && + printf "100644 good\0${bin_oid}GARBAGE" >corrupt-mid-tree && + corrupt_tree=$(git hash-object --literally -t tree -w \ + corrupt-mid-tree) && + corrupt_commit=$(git commit-tree "$corrupt_tree" \ + -p HEAD -m "mid-tree corruption") && + test_expect_code 128 check_connected \ + "$corrupt_commit" 2>err && + test_grep "too-short tree object" err + ) +' + +done + +# Algorithm selection. + +test_expect_success 'invalid transfer.connectivityCheck is rejected' ' + test_when_finished "rm -rf invalid-cfg-src invalid-cfg-dst" && + git init invalid-cfg-src && + test_commit -C invalid-cfg-src --no-tag base file.txt && + git clone invalid-cfg-src invalid-cfg-dst && + test_commit -C invalid-cfg-src --no-tag update file.txt updated && + git -C invalid-cfg-dst config transfer.connectivityCheck bogus && + test_must_fail git -C invalid-cfg-dst fetch origin main 2>err && + test_grep "unknown transfer.connectivityCheck" err +' + +test_expect_success 'push uses incremental when configured' ' + test_when_finished "rm -rf int-src int-dst.git" && + git init int-src && + test_commit -C int-src --no-tag base file.txt && + git clone --bare int-src int-dst.git && + test_commit -C int-src --no-tag update file.txt updated && + set_connectivity_check int-dst.git incremental && + GIT_TRACE2_EVENT="$(pwd)/push-trace.txt" \ + git -C int-src push ../int-dst.git main && + test_trace2_data_singular connectivity trees_loaded 2 \ + kh_val(m, pos)) + kh_val(m, pos) = state; +} + +struct work_item { + struct name_entry entry; + struct oid_array parent_trees; +}; + +struct verify_state { + kh_oid_tree_t *trees; + struct oidset trusted_blobs; + int trees_loaded; + int blobs_checked; + int exclude_promisor_objects; +}; + +/* + * Merge-walk the work list against one base tree entry, recording + * same-path parent subtrees as recursive comparison bases. + * Returns the updated work-list cursor. + */ +static size_t collect_subtree_bases(struct work_item *work, size_t nr_work, + size_t wi, const struct name_entry *entry) +{ + while (wi < nr_work) { + int cmp = base_name_compare( + work[wi].entry.path, work[wi].entry.pathlen, + work[wi].entry.mode, + entry->path, entry->pathlen, + entry->mode); + if (cmp > 0) + break; + if (cmp < 0) { + wi++; + continue; + } + if (S_ISDIR(work[wi].entry.mode) && + S_ISDIR(entry->mode)) + oid_array_append(&work[wi].parent_trees, + &entry->oid); + return wi + 1; + } + return wi; +} + +static void verify_blob(struct repository *repo, + const struct object_id *oid, + struct verify_state *vs) +{ + int type; + + if (oidset_contains(&vs->trusted_blobs, oid)) + return; + + vs->blobs_checked++; + type = odb_read_object_info(repo->objects, oid, NULL); + if (type == OBJ_BLOB) { + oidset_insert(&vs->trusted_blobs, oid); + return; + } + if (type >= 0) + die(_("object %s is a %s, not a blob"), + oid_to_hex(oid), type_name(type)); + if (vs->exclude_promisor_objects && + is_promisor_object(repo, oid)) + return; + die(_("missing blob object '%s'"), oid_to_hex(oid)); +} + +static void *read_tree_object(struct object_database *odb, + const struct object_id *oid, + size_t *sizep) +{ + enum object_type type; + void *buf = odb_read_object(odb, oid, &type, sizep); + + if (buf && type != OBJ_TREE) { + free(buf); + die(_("object %s is a %s, not a tree"), + oid_to_hex(oid), type_name(type)); + } + return buf; +} + +static void verify_tree(struct repository *repo, + const struct object_id *new_tree_oid, + const struct oid_array *base_trees, + struct verify_state *vs, int depth) +{ + struct tree_desc desc; + struct name_entry entry; + struct work_item *work = NULL; + size_t nr_work = 0, alloc_work = 0; + int need_subtree_bases = 0; + size_t i, tree_size; + void *tree_buf; + + if (depth > repo->settings.max_allowed_tree_depth) + die(_("exceeded maximum allowed tree depth")); + + if (tree_map_get(vs->trees, new_tree_oid) >= TREE_TRUSTED) + return; + + tree_buf = read_tree_object(repo->objects, new_tree_oid, &tree_size); + if (!tree_buf) { + if (vs->exclude_promisor_objects && + is_promisor_object(repo, new_tree_oid)) + return; + die(_("bad tree object %s"), + oid_to_hex(new_tree_oid)); + } + + vs->trees_loaded++; + init_tree_desc(&desc, new_tree_oid, tree_buf, tree_size); + + while (tree_entry(&desc, &entry)) { + if (S_ISGITLINK(entry.mode)) + continue; + if (S_ISDIR(entry.mode)) { + if (tree_map_get(vs->trees, &entry.oid) >= TREE_TRUSTED) + continue; + need_subtree_bases = 1; + } else { + if (oidset_contains(&vs->trusted_blobs, &entry.oid)) + continue; + } + ALLOC_GROW(work, nr_work + 1, alloc_work); + memset(&work[nr_work], 0, sizeof(work[nr_work])); + work[nr_work].entry = entry; + nr_work++; + } + + if (!nr_work) { + free(tree_buf); + goto done; + } + + for (i = 0; base_trees && i < base_trees->nr; i++) { + const struct object_id *base_oid = &base_trees->oid[i]; + int expanded = tree_map_get(vs->trees, base_oid) >= TREE_EXPANDED; + struct tree_desc base_desc; + struct name_entry scan_entry; + size_t wi = 0, base_size; + void *base_buf; + + if (expanded && !need_subtree_bases) + continue; + + base_buf = read_tree_object(repo->objects, base_oid, + &base_size); + if (!base_buf) { + if (vs->exclude_promisor_objects && + is_promisor_object(repo, base_oid)) + continue; + die(_("bad tree object %s"), + oid_to_hex(base_oid)); + } + + vs->trees_loaded++; + init_tree_desc(&base_desc, base_oid, base_buf, base_size); + + while (tree_entry(&base_desc, &scan_entry)) { + if (S_ISGITLINK(scan_entry.mode)) + continue; + + if (need_subtree_bases) + wi = collect_subtree_bases(work, nr_work, + wi, &scan_entry); + + if (!expanded) { + if (S_ISDIR(scan_entry.mode)) + tree_map_add(vs->trees, + &scan_entry.oid, + TREE_TRUSTED); + else + oidset_insert(&vs->trusted_blobs, + &scan_entry.oid); + } + } + + if (!expanded) + tree_map_add(vs->trees, base_oid, TREE_EXPANDED); + + free(base_buf); + } + + for (i = 0; i < nr_work; i++) { + if (S_ISDIR(work[i].entry.mode)) + verify_tree(repo, &work[i].entry.oid, + &work[i].parent_trees, vs, + depth + 1); + else + verify_blob(repo, &work[i].entry.oid, vs); + } + + free(tree_buf); + +done: + tree_map_add(vs->trees, new_tree_oid, TREE_EXPANDED); + for (i = 0; i < nr_work; i++) + oid_array_clear(&work[i].parent_trees); + free(work); +} + +static void verify_commit_tree(struct repository *repo, + struct commit *commit, + struct verify_state *vs) +{ + struct oid_array base_trees = OID_ARRAY_INIT; + struct commit_list *p; + + /* + * Parent trees are trusted: boundary parents are already + * connected, and earlier incoming parents were verified + * first due to the topological processing order. + */ + for (p = commit->parents; p; p = p->next) { + const struct object_id *tree_oid; + parse_commit_or_die(p->item); + tree_oid = get_commit_tree_oid(p->item); + tree_map_add(vs->trees, tree_oid, TREE_TRUSTED); + oid_array_append(&base_trees, tree_oid); + } + + verify_tree(repo, get_commit_tree_oid(commit), + &base_trees, vs, 0); + oid_array_clear(&base_trees); +} + +void verify_commits_incremental(struct repository *repo, + struct commit_list **commits, + int exclude_promisor_objects) +{ + struct verify_state vs = { 0 }; + struct commit_list *iter; + unsigned nr_before; + + vs.trees = kh_init_oid_tree(); + vs.exclude_promisor_objects = exclude_promisor_objects; + + /* + * Ancestors must be verified before descendants so that parent + * trees can be trusted without re-verification. Sort explicitly + * rather than relying on the caller's ordering. + * + * sort_in_topological_order() silently drops cycle members, + * so explicitly check if the size has changed. + */ + nr_before = commit_list_count(*commits); + sort_in_topological_order(commits, REV_SORT_IN_GRAPH_ORDER); + if (commit_list_count(*commits) < nr_before) + die(_("cycle detected in incoming commit graph")); + + *commits = commit_list_reverse(*commits); + + for (iter = *commits; iter; iter = iter->next) + verify_commit_tree(repo, iter->item, &vs); + + kh_destroy_oid_tree(vs.trees); + oidset_clear(&vs.trusted_blobs); + trace2_data_intmax("connectivity", repo, + "trees_loaded", vs.trees_loaded); + trace2_data_intmax("connectivity", repo, + "blobs_checked", vs.blobs_checked); +} diff --git a/tree-verify.h b/tree-verify.h new file mode 100644 index 00000000000000..6aadadff704d9e --- /dev/null +++ b/tree-verify.h @@ -0,0 +1,15 @@ +#ifndef TREE_VERIFY_H +#define TREE_VERIFY_H + +struct commit_list; +struct repository; + +/* + * Verify trees of commits incrementally against their parents. + * Dies on verification failure. + */ +void verify_commits_incremental(struct repository *repo, + struct commit_list **commits, + int exclude_promisor_objects); + +#endif /* TREE_VERIFY_H */