git/builtin/fsck.c
Junio C Hamano 1689c22c1c Merge branch 'jk/core-use-replace-refs'
A new configuration variable core.usereplacerefs has been added,
primarily to help server installations that want to ignore the
replace mechanism altogether.

* jk/core-use-replace-refs:
  add core.usereplacerefs config option
  check_replace_refs: rename to read_replace_refs
  check_replace_refs: fix outdated comment
2018-08-15 15:08:23 -07:00

853 lines
22 KiB
C

#include "builtin.h"
#include "cache.h"
#include "repository.h"
#include "config.h"
#include "commit.h"
#include "tree.h"
#include "blob.h"
#include "tag.h"
#include "refs.h"
#include "pack.h"
#include "cache-tree.h"
#include "tree-walk.h"
#include "fsck.h"
#include "parse-options.h"
#include "dir.h"
#include "progress.h"
#include "streaming.h"
#include "decorate.h"
#include "packfile.h"
#include "object-store.h"
#include "run-command.h"
#define REACHABLE 0x0001
#define SEEN 0x0002
#define HAS_OBJ 0x0004
/* This flag is set if something points to this object. */
#define USED 0x0008
static int show_root;
static int show_tags;
static int show_unreachable;
static int include_reflogs = 1;
static int check_full = 1;
static int connectivity_only;
static int check_strict;
static int keep_cache_objects;
static struct fsck_options fsck_walk_options = FSCK_OPTIONS_DEFAULT;
static struct fsck_options fsck_obj_options = FSCK_OPTIONS_DEFAULT;
static struct object_id head_oid;
static const char *head_points_at;
static int errors_found;
static int write_lost_and_found;
static int verbose;
static int show_progress = -1;
static int show_dangling = 1;
static int name_objects;
#define ERROR_OBJECT 01
#define ERROR_REACHABLE 02
#define ERROR_PACK 04
#define ERROR_REFS 010
#define ERROR_COMMIT_GRAPH 020
static const char *describe_object(struct object *obj)
{
static struct strbuf buf = STRBUF_INIT;
char *name = name_objects ?
lookup_decoration(fsck_walk_options.object_names, obj) : NULL;
strbuf_reset(&buf);
strbuf_addstr(&buf, oid_to_hex(&obj->oid));
if (name)
strbuf_addf(&buf, " (%s)", name);
return buf.buf;
}
static const char *printable_type(struct object *obj)
{
const char *ret;
if (obj->type == OBJ_NONE) {
enum object_type type = oid_object_info(the_repository,
&obj->oid, NULL);
if (type > 0)
object_as_type(the_repository, obj, type, 0);
}
ret = type_name(obj->type);
if (!ret)
ret = "unknown";
return ret;
}
static int fsck_config(const char *var, const char *value, void *cb)
{
if (strcmp(var, "fsck.skiplist") == 0) {
const char *path;
struct strbuf sb = STRBUF_INIT;
if (git_config_pathname(&path, var, value))
return 1;
strbuf_addf(&sb, "skiplist=%s", path);
free((char *)path);
fsck_set_msg_types(&fsck_obj_options, sb.buf);
strbuf_release(&sb);
return 0;
}
if (skip_prefix(var, "fsck.", &var)) {
fsck_set_msg_type(&fsck_obj_options, var, value);
return 0;
}
return git_default_config(var, value, cb);
}
static void objreport(struct object *obj, const char *msg_type,
const char *err)
{
fprintf(stderr, "%s in %s %s: %s\n",
msg_type, printable_type(obj), describe_object(obj), err);
}
static int objerror(struct object *obj, const char *err)
{
errors_found |= ERROR_OBJECT;
objreport(obj, "error", err);
return -1;
}
static int fsck_error_func(struct fsck_options *o,
struct object *obj, int type, const char *message)
{
objreport(obj, (type == FSCK_WARN) ? "warning" : "error", message);
return (type == FSCK_WARN) ? 0 : 1;
}
static struct object_array pending;
static int mark_object(struct object *obj, int type, void *data, struct fsck_options *options)
{
struct object *parent = data;
/*
* The only case data is NULL or type is OBJ_ANY is when
* mark_object_reachable() calls us. All the callers of
* that function has non-NULL obj hence ...
*/
if (!obj) {
/* ... these references to parent->fld are safe here */
printf("broken link from %7s %s\n",
printable_type(parent), describe_object(parent));
printf("broken link from %7s %s\n",
(type == OBJ_ANY ? "unknown" : type_name(type)), "unknown");
errors_found |= ERROR_REACHABLE;
return 1;
}
if (type != OBJ_ANY && obj->type != type)
/* ... and the reference to parent is safe here */
objerror(parent, "wrong object type in link");
if (obj->flags & REACHABLE)
return 0;
obj->flags |= REACHABLE;
if (is_promisor_object(&obj->oid))
/*
* Further recursion does not need to be performed on this
* object since it is a promisor object (so it does not need to
* be added to "pending").
*/
return 0;
if (!(obj->flags & HAS_OBJ)) {
if (parent && !has_object_file(&obj->oid)) {
printf("broken link from %7s %s\n",
printable_type(parent), describe_object(parent));
printf(" to %7s %s\n",
printable_type(obj), describe_object(obj));
errors_found |= ERROR_REACHABLE;
}
return 1;
}
add_object_array(obj, NULL, &pending);
return 0;
}
static void mark_object_reachable(struct object *obj)
{
mark_object(obj, OBJ_ANY, NULL, NULL);
}
static int traverse_one_object(struct object *obj)
{
int result = fsck_walk(obj, obj, &fsck_walk_options);
if (obj->type == OBJ_TREE) {
struct tree *tree = (struct tree *)obj;
free_tree_buffer(tree);
}
return result;
}
static int traverse_reachable(void)
{
struct progress *progress = NULL;
unsigned int nr = 0;
int result = 0;
if (show_progress)
progress = start_delayed_progress(_("Checking connectivity"), 0);
while (pending.nr) {
result |= traverse_one_object(object_array_pop(&pending));
display_progress(progress, ++nr);
}
stop_progress(&progress);
return !!result;
}
static int mark_used(struct object *obj, int type, void *data, struct fsck_options *options)
{
if (!obj)
return 1;
obj->flags |= USED;
return 0;
}
/*
* Check a single reachable object
*/
static void check_reachable_object(struct object *obj)
{
/*
* We obviously want the object to be parsed,
* except if it was in a pack-file and we didn't
* do a full fsck
*/
if (!(obj->flags & HAS_OBJ)) {
if (is_promisor_object(&obj->oid))
return;
if (has_object_pack(&obj->oid))
return; /* it is in pack - forget about it */
printf("missing %s %s\n", printable_type(obj),
describe_object(obj));
errors_found |= ERROR_REACHABLE;
return;
}
}
/*
* Check a single unreachable object
*/
static void check_unreachable_object(struct object *obj)
{
/*
* Missing unreachable object? Ignore it. It's not like
* we miss it (since it can't be reached), nor do we want
* to complain about it being unreachable (since it does
* not exist).
*/
if (!(obj->flags & HAS_OBJ))
return;
/*
* Unreachable object that exists? Show it if asked to,
* since this is something that is prunable.
*/
if (show_unreachable) {
printf("unreachable %s %s\n", printable_type(obj),
describe_object(obj));
return;
}
/*
* "!USED" means that nothing at all points to it, including
* other unreachable objects. In other words, it's the "tip"
* of some set of unreachable objects, usually a commit that
* got dropped.
*
* Such starting points are more interesting than some random
* set of unreachable objects, so we show them even if the user
* hasn't asked for _all_ unreachable objects. If you have
* deleted a branch by mistake, this is a prime candidate to
* start looking at, for example.
*/
if (!(obj->flags & USED)) {
if (show_dangling)
printf("dangling %s %s\n", printable_type(obj),
describe_object(obj));
if (write_lost_and_found) {
char *filename = git_pathdup("lost-found/%s/%s",
obj->type == OBJ_COMMIT ? "commit" : "other",
describe_object(obj));
FILE *f;
if (safe_create_leading_directories_const(filename)) {
error("Could not create lost-found");
free(filename);
return;
}
f = xfopen(filename, "w");
if (obj->type == OBJ_BLOB) {
if (stream_blob_to_fd(fileno(f), &obj->oid, NULL, 1))
die_errno("Could not write '%s'", filename);
} else
fprintf(f, "%s\n", describe_object(obj));
if (fclose(f))
die_errno("Could not finish '%s'",
filename);
free(filename);
}
return;
}
/*
* Otherwise? It's there, it's unreachable, and some other unreachable
* object points to it. Ignore it - it's not interesting, and we showed
* all the interesting cases above.
*/
}
static void check_object(struct object *obj)
{
if (verbose)
fprintf(stderr, "Checking %s\n", describe_object(obj));
if (obj->flags & REACHABLE)
check_reachable_object(obj);
else
check_unreachable_object(obj);
}
static void check_connectivity(void)
{
int i, max;
/* Traverse the pending reachable objects */
traverse_reachable();
/* Look up all the requirements, warn about missing objects.. */
max = get_max_object_index();
if (verbose)
fprintf(stderr, "Checking connectivity (%d objects)\n", max);
for (i = 0; i < max; i++) {
struct object *obj = get_indexed_object(i);
if (obj)
check_object(obj);
}
}
static int fsck_obj(struct object *obj, void *buffer, unsigned long size)
{
int err;
if (obj->flags & SEEN)
return 0;
obj->flags |= SEEN;
if (verbose)
fprintf(stderr, "Checking %s %s\n",
printable_type(obj), describe_object(obj));
if (fsck_walk(obj, NULL, &fsck_obj_options))
objerror(obj, "broken links");
err = fsck_object(obj, buffer, size, &fsck_obj_options);
if (err)
goto out;
if (obj->type == OBJ_COMMIT) {
struct commit *commit = (struct commit *) obj;
if (!commit->parents && show_root)
printf("root %s\n", describe_object(&commit->object));
}
if (obj->type == OBJ_TAG) {
struct tag *tag = (struct tag *) obj;
if (show_tags && tag->tagged) {
printf("tagged %s %s", printable_type(tag->tagged),
describe_object(tag->tagged));
printf(" (%s) in %s\n", tag->tag,
describe_object(&tag->object));
}
}
out:
if (obj->type == OBJ_TREE)
free_tree_buffer((struct tree *)obj);
if (obj->type == OBJ_COMMIT)
free_commit_buffer((struct commit *)obj);
return err;
}
static int fsck_obj_buffer(const struct object_id *oid, enum object_type type,
unsigned long size, void *buffer, int *eaten)
{
/*
* Note, buffer may be NULL if type is OBJ_BLOB. See
* verify_packfile(), data_valid variable for details.
*/
struct object *obj;
obj = parse_object_buffer(the_repository, oid, type, size, buffer,
eaten);
if (!obj) {
errors_found |= ERROR_OBJECT;
return error("%s: object corrupt or missing", oid_to_hex(oid));
}
obj->flags &= ~(REACHABLE | SEEN);
obj->flags |= HAS_OBJ;
return fsck_obj(obj, buffer, size);
}
static int default_refs;
static void fsck_handle_reflog_oid(const char *refname, struct object_id *oid,
timestamp_t timestamp)
{
struct object *obj;
if (!is_null_oid(oid)) {
obj = lookup_object(the_repository, oid->hash);
if (obj && (obj->flags & HAS_OBJ)) {
if (timestamp && name_objects)
add_decoration(fsck_walk_options.object_names,
obj,
xstrfmt("%s@{%"PRItime"}", refname, timestamp));
obj->flags |= USED;
mark_object_reachable(obj);
} else if (!is_promisor_object(oid)) {
error("%s: invalid reflog entry %s", refname, oid_to_hex(oid));
errors_found |= ERROR_REACHABLE;
}
}
}
static int fsck_handle_reflog_ent(struct object_id *ooid, struct object_id *noid,
const char *email, timestamp_t timestamp, int tz,
const char *message, void *cb_data)
{
const char *refname = cb_data;
if (verbose)
fprintf(stderr, "Checking reflog %s->%s\n",
oid_to_hex(ooid), oid_to_hex(noid));
fsck_handle_reflog_oid(refname, ooid, 0);
fsck_handle_reflog_oid(refname, noid, timestamp);
return 0;
}
static int fsck_handle_reflog(const char *logname, const struct object_id *oid,
int flag, void *cb_data)
{
for_each_reflog_ent(logname, fsck_handle_reflog_ent, (void *)logname);
return 0;
}
static int fsck_handle_ref(const char *refname, const struct object_id *oid,
int flag, void *cb_data)
{
struct object *obj;
obj = parse_object(the_repository, oid);
if (!obj) {
if (is_promisor_object(oid)) {
/*
* Increment default_refs anyway, because this is a
* valid ref.
*/
default_refs++;
return 0;
}
error("%s: invalid sha1 pointer %s", refname, oid_to_hex(oid));
errors_found |= ERROR_REACHABLE;
/* We'll continue with the rest despite the error.. */
return 0;
}
if (obj->type != OBJ_COMMIT && is_branch(refname)) {
error("%s: not a commit", refname);
errors_found |= ERROR_REFS;
}
default_refs++;
obj->flags |= USED;
if (name_objects)
add_decoration(fsck_walk_options.object_names,
obj, xstrdup(refname));
mark_object_reachable(obj);
return 0;
}
static void get_default_heads(void)
{
if (head_points_at && !is_null_oid(&head_oid))
fsck_handle_ref("HEAD", &head_oid, 0, NULL);
for_each_rawref(fsck_handle_ref, NULL);
if (include_reflogs)
for_each_reflog(fsck_handle_reflog, NULL);
/*
* Not having any default heads isn't really fatal, but
* it does mean that "--unreachable" no longer makes any
* sense (since in this case everything will obviously
* be unreachable by definition.
*
* Showing dangling objects is valid, though (as those
* dangling objects are likely lost heads).
*
* So we just print a warning about it, and clear the
* "show_unreachable" flag.
*/
if (!default_refs) {
fprintf(stderr, "notice: No default references\n");
show_unreachable = 0;
}
}
static int fsck_loose(const struct object_id *oid, const char *path, void *data)
{
struct object *obj;
enum object_type type;
unsigned long size;
void *contents;
int eaten;
if (read_loose_object(path, oid, &type, &size, &contents) < 0) {
errors_found |= ERROR_OBJECT;
error("%s: object corrupt or missing: %s",
oid_to_hex(oid), path);
return 0; /* keep checking other objects */
}
if (!contents && type != OBJ_BLOB)
BUG("read_loose_object streamed a non-blob");
obj = parse_object_buffer(the_repository, oid, type, size,
contents, &eaten);
if (!obj) {
errors_found |= ERROR_OBJECT;
error("%s: object could not be parsed: %s",
oid_to_hex(oid), path);
if (!eaten)
free(contents);
return 0; /* keep checking other objects */
}
obj->flags &= ~(REACHABLE | SEEN);
obj->flags |= HAS_OBJ;
if (fsck_obj(obj, contents, size))
errors_found |= ERROR_OBJECT;
if (!eaten)
free(contents);
return 0; /* keep checking other objects, even if we saw an error */
}
static int fsck_cruft(const char *basename, const char *path, void *data)
{
if (!starts_with(basename, "tmp_obj_"))
fprintf(stderr, "bad sha1 file: %s\n", path);
return 0;
}
static int fsck_subdir(unsigned int nr, const char *path, void *progress)
{
display_progress(progress, nr + 1);
return 0;
}
static void fsck_object_dir(const char *path)
{
struct progress *progress = NULL;
if (verbose)
fprintf(stderr, "Checking object directory\n");
if (show_progress)
progress = start_progress(_("Checking object directories"), 256);
for_each_loose_file_in_objdir(path, fsck_loose, fsck_cruft, fsck_subdir,
progress);
display_progress(progress, 256);
stop_progress(&progress);
}
static int fsck_head_link(void)
{
int null_is_error = 0;
if (verbose)
fprintf(stderr, "Checking HEAD link\n");
head_points_at = resolve_ref_unsafe("HEAD", 0, &head_oid, NULL);
if (!head_points_at) {
errors_found |= ERROR_REFS;
return error("Invalid HEAD");
}
if (!strcmp(head_points_at, "HEAD"))
/* detached HEAD */
null_is_error = 1;
else if (!starts_with(head_points_at, "refs/heads/")) {
errors_found |= ERROR_REFS;
return error("HEAD points to something strange (%s)",
head_points_at);
}
if (is_null_oid(&head_oid)) {
if (null_is_error) {
errors_found |= ERROR_REFS;
return error("HEAD: detached HEAD points at nothing");
}
fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
head_points_at + 11);
}
return 0;
}
static int fsck_cache_tree(struct cache_tree *it)
{
int i;
int err = 0;
if (verbose)
fprintf(stderr, "Checking cache tree\n");
if (0 <= it->entry_count) {
struct object *obj = parse_object(the_repository, &it->oid);
if (!obj) {
error("%s: invalid sha1 pointer in cache-tree",
oid_to_hex(&it->oid));
errors_found |= ERROR_REFS;
return 1;
}
obj->flags |= USED;
if (name_objects)
add_decoration(fsck_walk_options.object_names,
obj, xstrdup(":"));
mark_object_reachable(obj);
if (obj->type != OBJ_TREE)
err |= objerror(obj, "non-tree in cache-tree");
}
for (i = 0; i < it->subtree_nr; i++)
err |= fsck_cache_tree(it->down[i]->cache_tree);
return err;
}
static void mark_object_for_connectivity(const struct object_id *oid)
{
struct object *obj = lookup_unknown_object(oid->hash);
obj->flags |= HAS_OBJ;
}
static int mark_loose_for_connectivity(const struct object_id *oid,
const char *path,
void *data)
{
mark_object_for_connectivity(oid);
return 0;
}
static int mark_packed_for_connectivity(const struct object_id *oid,
struct packed_git *pack,
uint32_t pos,
void *data)
{
mark_object_for_connectivity(oid);
return 0;
}
static char const * const fsck_usage[] = {
N_("git fsck [<options>] [<object>...]"),
NULL
};
static struct option fsck_opts[] = {
OPT__VERBOSE(&verbose, N_("be verbose")),
OPT_BOOL(0, "unreachable", &show_unreachable, N_("show unreachable objects")),
OPT_BOOL(0, "dangling", &show_dangling, N_("show dangling objects")),
OPT_BOOL(0, "tags", &show_tags, N_("report tags")),
OPT_BOOL(0, "root", &show_root, N_("report root nodes")),
OPT_BOOL(0, "cache", &keep_cache_objects, N_("make index objects head nodes")),
OPT_BOOL(0, "reflogs", &include_reflogs, N_("make reflogs head nodes (default)")),
OPT_BOOL(0, "full", &check_full, N_("also consider packs and alternate objects")),
OPT_BOOL(0, "connectivity-only", &connectivity_only, N_("check only connectivity")),
OPT_BOOL(0, "strict", &check_strict, N_("enable more strict checking")),
OPT_BOOL(0, "lost-found", &write_lost_and_found,
N_("write dangling objects in .git/lost-found")),
OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
OPT_BOOL(0, "name-objects", &name_objects, N_("show verbose names for reachable objects")),
OPT_END(),
};
int cmd_fsck(int argc, const char **argv, const char *prefix)
{
int i;
struct alternate_object_database *alt;
/* fsck knows how to handle missing promisor objects */
fetch_if_missing = 0;
errors_found = 0;
read_replace_refs = 0;
argc = parse_options(argc, argv, prefix, fsck_opts, fsck_usage, 0);
fsck_walk_options.walk = mark_object;
fsck_obj_options.walk = mark_used;
fsck_obj_options.error_func = fsck_error_func;
if (check_strict)
fsck_obj_options.strict = 1;
if (show_progress == -1)
show_progress = isatty(2);
if (verbose)
show_progress = 0;
if (write_lost_and_found) {
check_full = 1;
include_reflogs = 0;
}
if (name_objects)
fsck_walk_options.object_names =
xcalloc(1, sizeof(struct decoration));
git_config(fsck_config, NULL);
fsck_head_link();
if (connectivity_only) {
for_each_loose_object(mark_loose_for_connectivity, NULL, 0);
for_each_packed_object(mark_packed_for_connectivity, NULL, 0);
} else {
struct alternate_object_database *alt_odb_list;
fsck_object_dir(get_object_directory());
prepare_alt_odb(the_repository);
alt_odb_list = the_repository->objects->alt_odb_list;
for (alt = alt_odb_list; alt; alt = alt->next)
fsck_object_dir(alt->path);
if (check_full) {
struct packed_git *p;
uint32_t total = 0, count = 0;
struct progress *progress = NULL;
if (show_progress) {
for (p = get_packed_git(the_repository); p;
p = p->next) {
if (open_pack_index(p))
continue;
total += p->num_objects;
}
progress = start_progress(_("Checking objects"), total);
}
for (p = get_packed_git(the_repository); p;
p = p->next) {
/* verify gives error messages itself */
if (verify_pack(p, fsck_obj_buffer,
progress, count))
errors_found |= ERROR_PACK;
count += p->num_objects;
}
stop_progress(&progress);
}
if (fsck_finish(&fsck_obj_options))
errors_found |= ERROR_OBJECT;
}
for (i = 0; i < argc; i++) {
const char *arg = argv[i];
struct object_id oid;
if (!get_oid(arg, &oid)) {
struct object *obj = lookup_object(the_repository,
oid.hash);
if (!obj || !(obj->flags & HAS_OBJ)) {
if (is_promisor_object(&oid))
continue;
error("%s: object missing", oid_to_hex(&oid));
errors_found |= ERROR_OBJECT;
continue;
}
obj->flags |= USED;
if (name_objects)
add_decoration(fsck_walk_options.object_names,
obj, xstrdup(arg));
mark_object_reachable(obj);
continue;
}
error("invalid parameter: expected sha1, got '%s'", arg);
errors_found |= ERROR_OBJECT;
}
/*
* If we've not been given any explicit head information, do the
* default ones from .git/refs. We also consider the index file
* in this case (ie this implies --cache).
*/
if (!argc) {
get_default_heads();
keep_cache_objects = 1;
}
if (keep_cache_objects) {
verify_index_checksum = 1;
verify_ce_order = 1;
read_cache();
for (i = 0; i < active_nr; i++) {
unsigned int mode;
struct blob *blob;
struct object *obj;
mode = active_cache[i]->ce_mode;
if (S_ISGITLINK(mode))
continue;
blob = lookup_blob(the_repository,
&active_cache[i]->oid);
if (!blob)
continue;
obj = &blob->object;
obj->flags |= USED;
if (name_objects)
add_decoration(fsck_walk_options.object_names,
obj,
xstrfmt(":%s", active_cache[i]->name));
mark_object_reachable(obj);
}
if (active_cache_tree)
fsck_cache_tree(active_cache_tree);
}
check_connectivity();
if (!git_config_get_bool("core.commitgraph", &i) && i) {
struct child_process commit_graph_verify = CHILD_PROCESS_INIT;
const char *verify_argv[] = { "commit-graph", "verify", NULL, NULL, NULL };
commit_graph_verify.argv = verify_argv;
commit_graph_verify.git_cmd = 1;
if (run_command(&commit_graph_verify))
errors_found |= ERROR_COMMIT_GRAPH;
prepare_alt_odb(the_repository);
for (alt = the_repository->objects->alt_odb_list; alt; alt = alt->next) {
verify_argv[2] = "--object-dir";
verify_argv[3] = alt->path;
if (run_command(&commit_graph_verify))
errors_found |= ERROR_COMMIT_GRAPH;
}
}
return errors_found;
}