Merge branch 'ab/commit-graph-fixes'

Code cleanup with more careful error checking before using data
read from the commit-graph file.

* ab/commit-graph-fixes:
commit-graph: improve & i18n error messages
commit-graph write: don't die if the existing graph is corrupt
commit-graph verify: detect inability to read the graph
commit-graph: don't pass filename to load_commit_graph_one_fd_st()
commit-graph: don't early exit(1) on e.g. "git status"
commit-graph: fix segfault on e.g. "git status"
commit-graph tests: test a graph that's too small
commit-graph tests: split up corrupt_graph_and_verify()

diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index 4ae502754c292d0e743ed8fbfdf9d5dda00d1dba..537fdfd0f0759e8cce2303af5a197ae77b2b879b 100644 (file)
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -42,6 +42,9 @@ static int graph_verify(int argc, const char **argv)
 {
        struct commit_graph *graph = NULL;
        char *graph_name;
+       int open_ok;
+       int fd;
+       struct stat st;
 
        static struct option builtin_commit_graph_verify_options[] = {
                OPT_STRING(0, "object-dir", &opts.obj_dir,
@@ -58,11 +61,16 @@ static int graph_verify(int argc, const char **argv)
                opts.obj_dir = get_object_directory();
 
        graph_name = get_commit_graph_filename(opts.obj_dir);
-       graph = load_commit_graph_one(graph_name);
+       open_ok = open_commit_graph(graph_name, &fd, &st);
+       if (!open_ok && errno == ENOENT)
+               return 0;
+       if (!open_ok)
+               die_errno(_("Could not open commit-graph '%s'"), graph_name);
+       graph = load_commit_graph_one_fd_st(fd, &st);
        FREE_AND_NULL(graph_name);
 
        if (!graph)
-               return 0;
+               return 1;
 
        UNLEAK(graph);
        return verify_commit_graph(the_repository, graph);
@@ -72,6 +80,9 @@ static int graph_read(int argc, const char **argv)
 {
        struct commit_graph *graph = NULL;
        char *graph_name;
+       int open_ok;
+       int fd;
+       struct stat st;
 
        static struct option builtin_commit_graph_read_options[] = {
                OPT_STRING(0, "object-dir", &opts.obj_dir,
@@ -88,10 +99,14 @@ static int graph_read(int argc, const char **argv)
                opts.obj_dir = get_object_directory();
 
        graph_name = get_commit_graph_filename(opts.obj_dir);
-       graph = load_commit_graph_one(graph_name);
 
+       open_ok = open_commit_graph(graph_name, &fd, &st);
+       if (!open_ok)
+               die_errno(_("Could not open commit-graph '%s'"), graph_name);
+
+       graph = load_commit_graph_one_fd_st(fd, &st);
        if (!graph)
-               die("graph file %s does not exist", graph_name);
+               return 1;
 
        FREE_AND_NULL(graph_name);
 

diff --git a/commit-graph.c b/commit-graph.c
index 47e9be0a3aad883c17221b11c972b8376a70a555..66865acbd7489df4f85ee2454fe05a9b346e7aa7 100644 (file)
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -80,25 +80,30 @@ static int commit_graph_compatible(struct repository *r)
        return 1;
 }
 
-struct commit_graph *load_commit_graph_one(const char *graph_file)
+int open_commit_graph(const char *graph_file, int *fd, struct stat *st)
+{
+       *fd = git_open(graph_file);
+       if (*fd < 0)
+               return 0;
+       if (fstat(*fd, st)) {
+               close(*fd);
+               return 0;
+       }
+       return 1;
+}
+
+struct commit_graph *load_commit_graph_one_fd_st(int fd, struct stat *st)
 {
        void *graph_map;
        size_t graph_size;
-       struct stat st;
        struct commit_graph *ret;
-       int fd = git_open(graph_file);
 
-       if (fd < 0)
-               return NULL;
-       if (fstat(fd, &st)) {
-               close(fd);
-               return NULL;
-       }
-       graph_size = xsize_t(st.st_size);
+       graph_size = xsize_t(st->st_size);
 
        if (graph_size < GRAPH_MIN_SIZE) {
                close(fd);
-               die(_("graph file %s is too small"), graph_file);
+               error(_("commit-graph file is too small"));
+               return NULL;
        }
        graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);
        ret = parse_commit_graph(graph_map, fd, graph_size);
@@ -106,12 +111,41 @@ struct commit_graph *load_commit_graph_one(const char *graph_file)
        if (!ret) {
                munmap(graph_map, graph_size);
                close(fd);
-               exit(1);
        }
 
        return ret;
 }
 
+static int verify_commit_graph_lite(struct commit_graph *g)
+{
+       /*
+        * Basic validation shared between parse_commit_graph()
+        * which'll be called every time the graph is used, and the
+        * much more expensive verify_commit_graph() used by
+        * "commit-graph verify".
+        *
+        * There should only be very basic checks here to ensure that
+        * we don't e.g. segfault in fill_commit_in_graph(), but
+        * because this is a very hot codepath nothing that e.g. loops
+        * over g->num_commits, or runs a checksum on the commit-graph
+        * itself.
+        */
+       if (!g->chunk_oid_fanout) {
+               error("commit-graph is missing the OID Fanout chunk");
+               return 1;
+       }
+       if (!g->chunk_oid_lookup) {
+               error("commit-graph is missing the OID Lookup chunk");
+               return 1;
+       }
+       if (!g->chunk_commit_data) {
+               error("commit-graph is missing the Commit Data chunk");
+               return 1;
+       }
+
+       return 0;
+}
+
 struct commit_graph *parse_commit_graph(void *graph_map, int fd,
                                        size_t graph_size)
 {
@@ -133,21 +167,21 @@ struct commit_graph *parse_commit_graph(void *graph_map, int fd,
 
        graph_signature = get_be32(data);
        if (graph_signature != GRAPH_SIGNATURE) {
-               error(_("graph signature %X does not match signature %X"),
+               error(_("commit-graph signature %X does not match signature %X"),
                      graph_signature, GRAPH_SIGNATURE);
                return NULL;
        }
 
        graph_version = *(unsigned char*)(data + 4);
        if (graph_version != GRAPH_VERSION) {
-               error(_("graph version %X does not match version %X"),
+               error(_("commit-graph version %X does not match version %X"),
                      graph_version, GRAPH_VERSION);
                return NULL;
        }
 
        hash_version = *(unsigned char*)(data + 5);
        if (hash_version != oid_version()) {
-               error(_("hash version %X does not match version %X"),
+               error(_("commit-graph hash version %X does not match version %X"),
                      hash_version, oid_version());
                return NULL;
        }
@@ -170,7 +204,7 @@ struct commit_graph *parse_commit_graph(void *graph_map, int fd,
 
                if (data + graph_size - chunk_lookup <
                    GRAPH_CHUNKLOOKUP_WIDTH) {
-                       error(_("chunk lookup table entry missing; graph file may be incomplete"));
+                       error(_("commit-graph chunk lookup table entry missing; file may be incomplete"));
                        free(graph);
                        return NULL;
                }
@@ -181,7 +215,7 @@ struct commit_graph *parse_commit_graph(void *graph_map, int fd,
                chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;
 
                if (chunk_offset > graph_size - the_hash_algo->rawsz) {
-                       error(_("improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32),
+                       error(_("commit-graph improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32),
                              (uint32_t)chunk_offset);
                        free(graph);
                        return NULL;
@@ -218,7 +252,7 @@ struct commit_graph *parse_commit_graph(void *graph_map, int fd,
                }
 
                if (chunk_repeated) {
-                       error(_("chunk id %08x appears multiple times"), chunk_id);
+                       error(_("commit-graph chunk id %08x appears multiple times"), chunk_id);
                        free(graph);
                        return NULL;
                }
@@ -233,9 +267,25 @@ struct commit_graph *parse_commit_graph(void *graph_map, int fd,
                last_chunk_offset = chunk_offset;
        }
 
+       if (verify_commit_graph_lite(graph))
+               return NULL;
+
        return graph;
 }
 
+static struct commit_graph *load_commit_graph_one(const char *graph_file)
+{
+
+       struct stat st;
+       int fd;
+       int open_ok = open_commit_graph(graph_file, &fd, &st);
+
+       if (!open_ok)
+               return NULL;
+
+       return load_commit_graph_one_fd_st(fd, &st);
+}
+
 static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
 {
        char *graph_name;
@@ -261,6 +311,10 @@ static int prepare_commit_graph(struct repository *r)
        struct object_directory *odb;
        int config_value;
 
+       if (git_env_bool(GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD, 0))
+               die("dying as requested by the '%s' variable on commit-graph load!",
+                   GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD);
+
        if (r->objects->commit_graph_attempted)
                return !!r->objects->commit_graph;
        r->objects->commit_graph_attempted = 1;
@@ -525,7 +579,7 @@ static void write_graph_chunk_data(struct hashfile *f, int hash_len,
                uint32_t packedDate[2];
                display_progress(progress, ++*progress_cnt);
 
-               parse_commit(*list);
+               parse_commit_no_graph(*list);
                hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
 
                parent = (*list)->parents;
@@ -722,7 +776,7 @@ static void close_reachable(struct packed_oid_list *oids, int report_progress)
                display_progress(progress, i + 1);
                commit = lookup_commit(the_repository, &oids->list[i]);
 
-               if (commit && !parse_commit(commit))
+               if (commit && !parse_commit_no_graph(commit))
                        add_missing_parents(oids, commit);
        }
        stop_progress(&progress);
@@ -971,7 +1025,7 @@ void write_commit_graph(const char *obj_dir,
                        continue;
 
                commits.list[commits.nr] = lookup_commit(the_repository, &oids.list[i]);
-               parse_commit(commits.list[commits.nr]);
+               parse_commit_no_graph(commits.list[commits.nr]);
 
                for (parent = commits.list[commits.nr]->parents;
                     parent; parent = parent->next)
@@ -1089,15 +1143,7 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
                return 1;
        }
 
-       verify_commit_graph_error = 0;
-
-       if (!g->chunk_oid_fanout)
-               graph_report("commit-graph is missing the OID Fanout chunk");
-       if (!g->chunk_oid_lookup)
-               graph_report("commit-graph is missing the OID Lookup chunk");
-       if (!g->chunk_commit_data)
-               graph_report("commit-graph is missing the Commit Data chunk");
-
+       verify_commit_graph_error = verify_commit_graph_lite(g);
        if (verify_commit_graph_error)
                return verify_commit_graph_error;
 
@@ -1116,7 +1162,7 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
                hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
 
                if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
-                       graph_report("commit-graph has incorrect OID order: %s then %s",
+                       graph_report(_("commit-graph has incorrect OID order: %s then %s"),
                                     oid_to_hex(&prev_oid),
                                     oid_to_hex(&cur_oid));
 
@@ -1126,14 +1172,14 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
                        uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
 
                        if (i != fanout_value)
-                               graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
+                               graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
                                             cur_fanout_pos, fanout_value, i);
                        cur_fanout_pos++;
                }
 
                graph_commit = lookup_commit(r, &cur_oid);
                if (!parse_commit_in_graph_one(r, g, graph_commit))
-                       graph_report("failed to parse %s from commit-graph",
+                       graph_report(_("failed to parse commit %s from commit-graph"),
                                     oid_to_hex(&cur_oid));
        }
 
@@ -1141,7 +1187,7 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
                uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
 
                if (g->num_commits != fanout_value)
-                       graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
+                       graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
                                     cur_fanout_pos, fanout_value, i);
 
                cur_fanout_pos++;
@@ -1163,14 +1209,14 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
                graph_commit = lookup_commit(r, &cur_oid);
                odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
                if (parse_commit_internal(odb_commit, 0, 0)) {
-                       graph_report("failed to parse %s from object database",
+                       graph_report(_("failed to parse commit %s from object database for commit-graph"),
                                     oid_to_hex(&cur_oid));
                        continue;
                }
 
                if (!oideq(&get_commit_tree_in_graph_one(r, g, graph_commit)->object.oid,
                           get_commit_tree_oid(odb_commit)))
-                       graph_report("root tree OID for commit %s in commit-graph is %s != %s",
+                       graph_report(_("root tree OID for commit %s in commit-graph is %s != %s"),
                                     oid_to_hex(&cur_oid),
                                     oid_to_hex(get_commit_tree_oid(graph_commit)),
                                     oid_to_hex(get_commit_tree_oid(odb_commit)));
@@ -1180,13 +1226,13 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
 
                while (graph_parents) {
                        if (odb_parents == NULL) {
-                               graph_report("commit-graph parent list for commit %s is too long",
+                               graph_report(_("commit-graph parent list for commit %s is too long"),
                                             oid_to_hex(&cur_oid));
                                break;
                        }
 
                        if (!oideq(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
-                               graph_report("commit-graph parent for %s is %s != %s",
+                               graph_report(_("commit-graph parent for %s is %s != %s"),
                                             oid_to_hex(&cur_oid),
                                             oid_to_hex(&graph_parents->item->object.oid),
                                             oid_to_hex(&odb_parents->item->object.oid));
@@ -1199,16 +1245,16 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
                }
 
                if (odb_parents != NULL)
-                       graph_report("commit-graph parent list for commit %s terminates early",
+                       graph_report(_("commit-graph parent list for commit %s terminates early"),
                                     oid_to_hex(&cur_oid));
 
                if (!graph_commit->generation) {
                        if (generation_zero == GENERATION_NUMBER_EXISTS)
-                               graph_report("commit-graph has generation number zero for commit %s, but non-zero elsewhere",
+                               graph_report(_("commit-graph has generation number zero for commit %s, but non-zero elsewhere"),
                                             oid_to_hex(&cur_oid));
                        generation_zero = GENERATION_ZERO_EXISTS;
                } else if (generation_zero == GENERATION_ZERO_EXISTS)
-                       graph_report("commit-graph has non-zero generation number for commit %s, but zero elsewhere",
+                       graph_report(_("commit-graph has non-zero generation number for commit %s, but zero elsewhere"),
                                     oid_to_hex(&cur_oid));
 
                if (generation_zero == GENERATION_ZERO_EXISTS)
@@ -1223,13 +1269,13 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
                        max_generation--;
 
                if (graph_commit->generation != max_generation + 1)
-                       graph_report("commit-graph generation for commit %s is %u != %u",
+                       graph_report(_("commit-graph generation for commit %s is %u != %u"),
                                     oid_to_hex(&cur_oid),
                                     graph_commit->generation,
                                     max_generation + 1);
 
                if (graph_commit->date != odb_commit->date)
-                       graph_report("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime,
+                       graph_report(_("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime),
                                     oid_to_hex(&cur_oid),
                                     graph_commit->date,
                                     odb_commit->date);

diff --git a/commit-graph.h b/commit-graph.h
index 096d8bac340514916c852268ef37c7b97190799a..7dfb8c896fc35f633c73221ec639ca9c425338ab 100644 (file)
--- a/commit-graph.h
+++ b/commit-graph.h
@@ -7,10 +7,12 @@
 #include "cache.h"
 
 #define GIT_TEST_COMMIT_GRAPH "GIT_TEST_COMMIT_GRAPH"
+#define GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD "GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD"
 
 struct commit;
 
 char *get_commit_graph_filename(const char *obj_dir);
+int open_commit_graph(const char *graph_file, int *fd, struct stat *st);
 
 /*
  * Given a commit struct, try to fill the commit struct info, including:
@@ -52,7 +54,7 @@ struct commit_graph {
        const unsigned char *chunk_extra_edges;
 };
 
-struct commit_graph *load_commit_graph_one(const char *graph_file);
+struct commit_graph *load_commit_graph_one_fd_st(int fd, struct stat *st);
 
 struct commit_graph *parse_commit_graph(void *graph_map, int fd,
                                        size_t graph_size);

diff --git a/commit.h b/commit.h
index 42728c2906608a9f4f1724e02b16d913b74b8728..5d33477e788633e12bf4cfb5319a79d5a7abf586 100644 (file)
--- a/commit.h
+++ b/commit.h
@@ -89,6 +89,12 @@ static inline int repo_parse_commit(struct repository *r, struct commit *item)
 {
        return repo_parse_commit_gently(r, item, 0);
 }
+
+static inline int parse_commit_no_graph(struct commit *commit)
+{
+       return repo_parse_commit_internal(the_repository, commit, 0, 0);
+}
+
 #ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
 #define parse_commit_internal(item, quiet, use) repo_parse_commit_internal(the_repository, item, quiet, use)
 #define parse_commit_gently(item, quiet) repo_parse_commit_gently(the_repository, item, quiet)

diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index 069e4e28e42d69e7b892112f3ba3743e4e13edac..840ad4d8accbfef59e2c9ade82105cc717f6866c 100755 (executable)
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -366,6 +366,26 @@ GRAPH_OCTOPUS_DATA_OFFSET=$(($GRAPH_COMMIT_DATA_OFFSET + \
 GRAPH_BYTE_OCTOPUS=$(($GRAPH_OCTOPUS_DATA_OFFSET + 4))
 GRAPH_BYTE_FOOTER=$(($GRAPH_OCTOPUS_DATA_OFFSET + 4 * $NUM_OCTOPUS_EDGES))
 
+corrupt_graph_setup() {
+       cd "$TRASH_DIRECTORY/full" &&
+       test_when_finished mv commit-graph-backup $objdir/info/commit-graph &&
+       cp $objdir/info/commit-graph commit-graph-backup
+}
+
+corrupt_graph_verify() {
+       grepstr=$1
+       test_must_fail git commit-graph verify 2>test_err &&
+       grep -v "^+" test_err >err &&
+       test_i18ngrep "$grepstr" err &&
+       if test "$2" != "no-copy"
+       then
+               cp $objdir/info/commit-graph commit-graph-pre-write-test
+       fi &&
+       git status --short &&
+       GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD=true git commit-graph write &&
+       git commit-graph verify
+}
+
 # usage: corrupt_graph_and_verify <position> <data> <string> [<zero_pos>]
 # Manipulates the commit-graph file at the position
 # by inserting the data, optionally zeroing the file
@@ -376,19 +396,28 @@ corrupt_graph_and_verify() {
        pos=$1
        data="${2:-\0}"
        grepstr=$3
-       cd "$TRASH_DIRECTORY/full" &&
+       corrupt_graph_setup &&
        orig_size=$(wc -c < $objdir/info/commit-graph) &&
        zero_pos=${4:-${orig_size}} &&
-       test_when_finished mv commit-graph-backup $objdir/info/commit-graph &&
-       cp $objdir/info/commit-graph commit-graph-backup &&
        printf "$data" | dd of="$objdir/info/commit-graph" bs=1 seek="$pos" conv=notrunc &&
        dd of="$objdir/info/commit-graph" bs=1 seek="$zero_pos" if=/dev/null &&
        generate_zero_bytes $(($orig_size - $zero_pos)) >>"$objdir/info/commit-graph" &&
-       test_must_fail git commit-graph verify 2>test_err &&
-       grep -v "^+" test_err >err &&
-       test_i18ngrep "$grepstr" err
+       corrupt_graph_verify "$grepstr"
+
 }
 
+test_expect_success POSIXPERM,SANITY 'detect permission problem' '
+       corrupt_graph_setup &&
+       chmod 000 $objdir/info/commit-graph &&
+       corrupt_graph_verify "Could not open" "no-copy"
+'
+
+test_expect_success 'detect too small' '
+       corrupt_graph_setup &&
+       echo "a small graph" >$objdir/info/commit-graph &&
+       corrupt_graph_verify "too small"
+'
+
 test_expect_success 'detect bad signature' '
        corrupt_graph_and_verify 0 "\0" \
                "graph signature"
@@ -499,6 +528,7 @@ test_expect_success 'git fsck (checks commit-graph)' '
        git fsck &&
        corrupt_graph_and_verify $GRAPH_BYTE_FOOTER "\00" \
                "incorrect checksum" &&
+       cp commit-graph-pre-write-test $objdir/info/commit-graph &&
        test_must_fail git fsck
 '