git/builtin-fsck.c
Junio C Hamano eadbcd498a Merge branch 'mk/maint-parse-careful'
* mk/maint-parse-careful:
  receive-pack: use strict mode for unpacking objects
  index-pack: introduce checking mode
  unpack-objects: prevent writing of inconsistent objects
  unpack-object: cache for non written objects
  add common fsck error printing function
  builtin-fsck: move common object checking code to fsck.c
  builtin-fsck: reports missing parent commits
  Remove unused object-ref code
  builtin-fsck: move away from object-refs to fsck_walk
  add generic, type aware object chain walker

Conflicts:

	Makefile
	builtin-fsck.c
2008-03-02 15:11:07 -08:00

652 lines
15 KiB
C

#include "builtin.h"
#include "cache.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"
#define REACHABLE 0x0001
#define SEEN 0x0002
static int show_root;
static int show_tags;
static int show_unreachable;
static int include_reflogs = 1;
static int check_full;
static int check_strict;
static int keep_cache_objects;
static unsigned char head_sha1[20];
static int errors_found;
static int write_lost_and_found;
static int verbose;
#define ERROR_OBJECT 01
#define ERROR_REACHABLE 02
#ifdef NO_D_INO_IN_DIRENT
#define SORT_DIRENT 0
#define DIRENT_SORT_HINT(de) 0
#else
#define SORT_DIRENT 1
#define DIRENT_SORT_HINT(de) ((de)->d_ino)
#endif
static void objreport(struct object *obj, const char *severity,
const char *err, va_list params)
{
fprintf(stderr, "%s in %s %s: ",
severity, typename(obj->type), sha1_to_hex(obj->sha1));
vfprintf(stderr, err, params);
fputs("\n", stderr);
}
static int objerror(struct object *obj, const char *err, ...)
{
va_list params;
va_start(params, err);
errors_found |= ERROR_OBJECT;
objreport(obj, "error", err, params);
va_end(params);
return -1;
}
static int fsck_error_func(struct object *obj, int type, const char *err, ...)
{
va_list params;
va_start(params, err);
objreport(obj, (type == FSCK_WARN) ? "warning" : "error", err, params);
va_end(params);
return (type == FSCK_WARN) ? 0 : 1;
}
static int mark_object(struct object *obj, int type, void *data)
{
struct tree *tree = NULL;
struct object *parent = data;
int result;
if (!obj) {
printf("broken link from %7s %s\n",
typename(parent->type), sha1_to_hex(parent->sha1));
printf("broken link from %7s %s\n",
(type == OBJ_ANY ? "unknown" : typename(type)), "unknown");
errors_found |= ERROR_REACHABLE;
return 1;
}
if (type != OBJ_ANY && obj->type != type)
objerror(parent, "wrong object type in link");
if (obj->flags & REACHABLE)
return 0;
obj->flags |= REACHABLE;
if (!obj->parsed) {
if (parent && !has_sha1_file(obj->sha1)) {
printf("broken link from %7s %s\n",
typename(parent->type), sha1_to_hex(parent->sha1));
printf(" to %7s %s\n",
typename(obj->type), sha1_to_hex(obj->sha1));
errors_found |= ERROR_REACHABLE;
}
return 1;
}
if (obj->type == OBJ_TREE) {
obj->parsed = 0;
tree = (struct tree *)obj;
if (parse_tree(tree) < 0)
return 1; /* error already displayed */
}
result = fsck_walk(obj, mark_object, obj);
if (tree) {
free(tree->buffer);
tree->buffer = NULL;
}
if (result < 0)
result = 1;
return result;
}
static void mark_object_reachable(struct object *obj)
{
mark_object(obj, OBJ_ANY, 0);
}
static int mark_used(struct object *obj, int type, void *data)
{
if (!obj)
return 1;
obj->used = 1;
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->parsed) {
if (has_sha1_pack(obj->sha1, NULL))
return; /* it is in pack - forget about it */
printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
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->parsed)
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", typename(obj->type), sha1_to_hex(obj->sha1));
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->used) {
printf("dangling %s %s\n", typename(obj->type),
sha1_to_hex(obj->sha1));
if (write_lost_and_found) {
char *filename = git_path("lost-found/%s/%s",
obj->type == OBJ_COMMIT ? "commit" : "other",
sha1_to_hex(obj->sha1));
FILE *f;
if (safe_create_leading_directories(filename)) {
error("Could not create lost-found");
return;
}
if (!(f = fopen(filename, "w")))
die("Could not open %s", filename);
if (obj->type == OBJ_BLOB) {
enum object_type type;
unsigned long size;
char *buf = read_sha1_file(obj->sha1,
&type, &size);
if (buf) {
fwrite(buf, size, 1, f);
free(buf);
}
} else
fprintf(f, "%s\n", sha1_to_hex(obj->sha1));
fclose(f);
}
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", sha1_to_hex(obj->sha1));
if (obj->flags & REACHABLE)
check_reachable_object(obj);
else
check_unreachable_object(obj);
}
static void check_connectivity(void)
{
int i, max;
/* 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_sha1(const unsigned char *sha1)
{
struct object *obj = parse_object(sha1);
if (!obj) {
errors_found |= ERROR_OBJECT;
return error("%s: object corrupt or missing",
sha1_to_hex(sha1));
}
if (obj->flags & SEEN)
return 0;
obj->flags |= SEEN;
if (verbose)
fprintf(stderr, "Checking %s %s\n",
typename(obj->type), sha1_to_hex(obj->sha1));
if (fsck_walk(obj, mark_used, 0))
objerror(obj, "broken links");
if (fsck_object(obj, check_strict, fsck_error_func))
return -1;
if (obj->type == OBJ_TREE) {
struct tree *item = (struct tree *) obj;
free(item->buffer);
item->buffer = NULL;
}
if (obj->type == OBJ_COMMIT) {
struct commit *commit = (struct commit *) obj;
free(commit->buffer);
commit->buffer = NULL;
if (!commit->parents && show_root)
printf("root %s\n", sha1_to_hex(commit->object.sha1));
}
if (obj->type == OBJ_TAG) {
struct tag *tag = (struct tag *) obj;
if (show_tags && tag->tagged) {
printf("tagged %s %s", typename(tag->tagged->type), sha1_to_hex(tag->tagged->sha1));
printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
}
}
return 0;
}
/*
* This is the sorting chunk size: make it reasonably
* big so that we can sort well..
*/
#define MAX_SHA1_ENTRIES (1024)
struct sha1_entry {
unsigned long ino;
unsigned char sha1[20];
};
static struct {
unsigned long nr;
struct sha1_entry *entry[MAX_SHA1_ENTRIES];
} sha1_list;
static int ino_compare(const void *_a, const void *_b)
{
const struct sha1_entry *a = _a, *b = _b;
unsigned long ino1 = a->ino, ino2 = b->ino;
return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
}
static void fsck_sha1_list(void)
{
int i, nr = sha1_list.nr;
if (SORT_DIRENT)
qsort(sha1_list.entry, nr,
sizeof(struct sha1_entry *), ino_compare);
for (i = 0; i < nr; i++) {
struct sha1_entry *entry = sha1_list.entry[i];
unsigned char *sha1 = entry->sha1;
sha1_list.entry[i] = NULL;
fsck_sha1(sha1);
free(entry);
}
sha1_list.nr = 0;
}
static void add_sha1_list(unsigned char *sha1, unsigned long ino)
{
struct sha1_entry *entry = xmalloc(sizeof(*entry));
int nr;
entry->ino = ino;
hashcpy(entry->sha1, sha1);
nr = sha1_list.nr;
if (nr == MAX_SHA1_ENTRIES) {
fsck_sha1_list();
nr = 0;
}
sha1_list.entry[nr] = entry;
sha1_list.nr = ++nr;
}
static void fsck_dir(int i, char *path)
{
DIR *dir = opendir(path);
struct dirent *de;
if (!dir)
return;
if (verbose)
fprintf(stderr, "Checking directory %s\n", path);
while ((de = readdir(dir)) != NULL) {
char name[100];
unsigned char sha1[20];
int len = strlen(de->d_name);
switch (len) {
case 2:
if (de->d_name[1] != '.')
break;
case 1:
if (de->d_name[0] != '.')
break;
continue;
case 38:
sprintf(name, "%02x", i);
memcpy(name+2, de->d_name, len+1);
if (get_sha1_hex(name, sha1) < 0)
break;
add_sha1_list(sha1, DIRENT_SORT_HINT(de));
continue;
}
fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
}
closedir(dir);
}
static int default_refs;
static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
const char *email, unsigned long timestamp, int tz,
const char *message, void *cb_data)
{
struct object *obj;
if (verbose)
fprintf(stderr, "Checking reflog %s->%s\n",
sha1_to_hex(osha1), sha1_to_hex(nsha1));
if (!is_null_sha1(osha1)) {
obj = lookup_object(osha1);
if (obj) {
obj->used = 1;
mark_object_reachable(obj);
}
}
obj = lookup_object(nsha1);
if (obj) {
obj->used = 1;
mark_object_reachable(obj);
}
return 0;
}
static int fsck_handle_reflog(const char *logname, const unsigned char *sha1, int flag, void *cb_data)
{
for_each_reflog_ent(logname, fsck_handle_reflog_ent, NULL);
return 0;
}
static int is_branch(const char *refname)
{
return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
}
static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
{
struct object *obj;
obj = parse_object(sha1);
if (!obj) {
error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
/* 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);
default_refs++;
obj->used = 1;
mark_object_reachable(obj);
return 0;
}
static void get_default_heads(void)
{
for_each_ref(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 void fsck_object_dir(const char *path)
{
int i;
if (verbose)
fprintf(stderr, "Checking object directory\n");
for (i = 0; i < 256; i++) {
static char dir[4096];
sprintf(dir, "%s/%02x", path, i);
fsck_dir(i, dir);
}
fsck_sha1_list();
}
static int fsck_head_link(void)
{
unsigned char sha1[20];
int flag;
int null_is_error = 0;
const char *head_points_at = resolve_ref("HEAD", sha1, 0, &flag);
if (verbose)
fprintf(stderr, "Checking HEAD link\n");
if (!head_points_at)
return error("Invalid HEAD");
if (!strcmp(head_points_at, "HEAD"))
/* detached HEAD */
null_is_error = 1;
else if (prefixcmp(head_points_at, "refs/heads/"))
return error("HEAD points to something strange (%s)",
head_points_at);
if (is_null_sha1(sha1)) {
if (null_is_error)
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(it->sha1);
if (!obj) {
error("%s: invalid sha1 pointer in cache-tree",
sha1_to_hex(it->sha1));
return 1;
}
mark_object_reachable(obj);
obj->used = 1;
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 char const * const fsck_usage[] = {
"git-fsck [options] [<object>...]",
NULL
};
static struct option fsck_opts[] = {
OPT__VERBOSE(&verbose),
OPT_BOOLEAN(0, "unreachable", &show_unreachable, "show unreachable objects"),
OPT_BOOLEAN(0, "tags", &show_tags, "report tags"),
OPT_BOOLEAN(0, "root", &show_root, "report root nodes"),
OPT_BOOLEAN(0, "cache", &keep_cache_objects, "make index objects head nodes"),
OPT_BOOLEAN(0, "reflogs", &include_reflogs, "make reflogs head nodes (default)"),
OPT_BOOLEAN(0, "full", &check_full, "also consider alternate objects"),
OPT_BOOLEAN(0, "strict", &check_strict, "enable more strict checking"),
OPT_BOOLEAN(0, "lost-found", &write_lost_and_found,
"write dangling objects in .git/lost-found"),
OPT_END(),
};
int cmd_fsck(int argc, const char **argv, const char *prefix)
{
int i, heads;
errors_found = 0;
argc = parse_options(argc, argv, fsck_opts, fsck_usage, 0);
if (write_lost_and_found) {
check_full = 1;
include_reflogs = 0;
}
fsck_head_link();
fsck_object_dir(get_object_directory());
if (check_full) {
struct alternate_object_database *alt;
struct packed_git *p;
prepare_alt_odb();
for (alt = alt_odb_list; alt; alt = alt->next) {
char namebuf[PATH_MAX];
int namelen = alt->name - alt->base;
memcpy(namebuf, alt->base, namelen);
namebuf[namelen - 1] = 0;
fsck_object_dir(namebuf);
}
prepare_packed_git();
for (p = packed_git; p; p = p->next)
/* verify gives error messages itself */
verify_pack(p, 0);
for (p = packed_git; p; p = p->next) {
uint32_t j, num;
if (open_pack_index(p))
continue;
num = p->num_objects;
for (j = 0; j < num; j++)
fsck_sha1(nth_packed_object_sha1(p, j));
}
}
heads = 0;
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (!get_sha1(arg, head_sha1)) {
struct object *obj = lookup_object(head_sha1);
/* Error is printed by lookup_object(). */
if (!obj)
continue;
obj->used = 1;
mark_object_reachable(obj);
heads++;
continue;
}
error("invalid parameter: expected sha1, got '%s'", arg);
}
/*
* 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 (!heads) {
get_default_heads();
keep_cache_objects = 1;
}
if (keep_cache_objects) {
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(active_cache[i]->sha1);
if (!blob)
continue;
obj = &blob->object;
obj->used = 1;
mark_object_reachable(obj);
}
if (active_cache_tree)
fsck_cache_tree(active_cache_tree);
}
check_connectivity();
return errors_found;
}