Merge branch 'mm/keyid-docs'
[git] / builtin / fsck.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "commit.h"
4 #include "tree.h"
5 #include "blob.h"
6 #include "tag.h"
7 #include "refs.h"
8 #include "pack.h"
9 #include "cache-tree.h"
10 #include "tree-walk.h"
11 #include "fsck.h"
12 #include "parse-options.h"
13 #include "dir.h"
14 #include "progress.h"
15 #include "streaming.h"
16
17 #define REACHABLE 0x0001
18 #define SEEN      0x0002
19 #define HAS_OBJ   0x0004
20
21 static int show_root;
22 static int show_tags;
23 static int show_unreachable;
24 static int include_reflogs = 1;
25 static int check_full = 1;
26 static int connectivity_only;
27 static int check_strict;
28 static int keep_cache_objects;
29 static struct fsck_options fsck_walk_options = FSCK_OPTIONS_DEFAULT;
30 static struct fsck_options fsck_obj_options = FSCK_OPTIONS_DEFAULT;
31 static struct object_id head_oid;
32 static const char *head_points_at;
33 static int errors_found;
34 static int write_lost_and_found;
35 static int verbose;
36 static int show_progress = -1;
37 static int show_dangling = 1;
38 #define ERROR_OBJECT 01
39 #define ERROR_REACHABLE 02
40 #define ERROR_PACK 04
41
42 #ifdef NO_D_INO_IN_DIRENT
43 #define SORT_DIRENT 0
44 #define DIRENT_SORT_HINT(de) 0
45 #else
46 #define SORT_DIRENT 1
47 #define DIRENT_SORT_HINT(de) ((de)->d_ino)
48 #endif
49
50 static int fsck_config(const char *var, const char *value, void *cb)
51 {
52         if (strcmp(var, "fsck.skiplist") == 0) {
53                 const char *path;
54                 struct strbuf sb = STRBUF_INIT;
55
56                 if (git_config_pathname(&path, var, value))
57                         return 1;
58                 strbuf_addf(&sb, "skiplist=%s", path);
59                 free((char *)path);
60                 fsck_set_msg_types(&fsck_obj_options, sb.buf);
61                 strbuf_release(&sb);
62                 return 0;
63         }
64
65         if (skip_prefix(var, "fsck.", &var)) {
66                 fsck_set_msg_type(&fsck_obj_options, var, value);
67                 return 0;
68         }
69
70         return git_default_config(var, value, cb);
71 }
72
73 static void objreport(struct object *obj, const char *msg_type,
74                         const char *err)
75 {
76         fprintf(stderr, "%s in %s %s: %s\n",
77                 msg_type, typename(obj->type), sha1_to_hex(obj->sha1), err);
78 }
79
80 static int objerror(struct object *obj, const char *err)
81 {
82         errors_found |= ERROR_OBJECT;
83         objreport(obj, "error", err);
84         return -1;
85 }
86
87 static int fsck_error_func(struct object *obj, int type, const char *message)
88 {
89         objreport(obj, (type == FSCK_WARN) ? "warning" : "error", message);
90         return (type == FSCK_WARN) ? 0 : 1;
91 }
92
93 static struct object_array pending;
94
95 static int mark_object(struct object *obj, int type, void *data, struct fsck_options *options)
96 {
97         struct object *parent = data;
98
99         /*
100          * The only case data is NULL or type is OBJ_ANY is when
101          * mark_object_reachable() calls us.  All the callers of
102          * that function has non-NULL obj hence ...
103          */
104         if (!obj) {
105                 /* ... these references to parent->fld are safe here */
106                 printf("broken link from %7s %s\n",
107                            typename(parent->type), sha1_to_hex(parent->sha1));
108                 printf("broken link from %7s %s\n",
109                            (type == OBJ_ANY ? "unknown" : typename(type)), "unknown");
110                 errors_found |= ERROR_REACHABLE;
111                 return 1;
112         }
113
114         if (type != OBJ_ANY && obj->type != type)
115                 /* ... and the reference to parent is safe here */
116                 objerror(parent, "wrong object type in link");
117
118         if (obj->flags & REACHABLE)
119                 return 0;
120         obj->flags |= REACHABLE;
121         if (!(obj->flags & HAS_OBJ)) {
122                 if (parent && !has_sha1_file(obj->sha1)) {
123                         printf("broken link from %7s %s\n",
124                                  typename(parent->type), sha1_to_hex(parent->sha1));
125                         printf("              to %7s %s\n",
126                                  typename(obj->type), sha1_to_hex(obj->sha1));
127                         errors_found |= ERROR_REACHABLE;
128                 }
129                 return 1;
130         }
131
132         add_object_array(obj, NULL, &pending);
133         return 0;
134 }
135
136 static void mark_object_reachable(struct object *obj)
137 {
138         mark_object(obj, OBJ_ANY, NULL, NULL);
139 }
140
141 static int traverse_one_object(struct object *obj)
142 {
143         int result;
144         struct tree *tree = NULL;
145
146         if (obj->type == OBJ_TREE) {
147                 tree = (struct tree *)obj;
148                 if (parse_tree(tree) < 0)
149                         return 1; /* error already displayed */
150         }
151         result = fsck_walk(obj, obj, &fsck_walk_options);
152         if (tree)
153                 free_tree_buffer(tree);
154         return result;
155 }
156
157 static int traverse_reachable(void)
158 {
159         struct progress *progress = NULL;
160         unsigned int nr = 0;
161         int result = 0;
162         if (show_progress)
163                 progress = start_progress_delay(_("Checking connectivity"), 0, 0, 2);
164         while (pending.nr) {
165                 struct object_array_entry *entry;
166                 struct object *obj;
167
168                 entry = pending.objects + --pending.nr;
169                 obj = entry->item;
170                 result |= traverse_one_object(obj);
171                 display_progress(progress, ++nr);
172         }
173         stop_progress(&progress);
174         return !!result;
175 }
176
177 static int mark_used(struct object *obj, int type, void *data, struct fsck_options *options)
178 {
179         if (!obj)
180                 return 1;
181         obj->used = 1;
182         return 0;
183 }
184
185 /*
186  * Check a single reachable object
187  */
188 static void check_reachable_object(struct object *obj)
189 {
190         /*
191          * We obviously want the object to be parsed,
192          * except if it was in a pack-file and we didn't
193          * do a full fsck
194          */
195         if (!(obj->flags & HAS_OBJ)) {
196                 if (has_sha1_pack(obj->sha1))
197                         return; /* it is in pack - forget about it */
198                 if (connectivity_only && has_sha1_file(obj->sha1))
199                         return;
200                 printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
201                 errors_found |= ERROR_REACHABLE;
202                 return;
203         }
204 }
205
206 /*
207  * Check a single unreachable object
208  */
209 static void check_unreachable_object(struct object *obj)
210 {
211         /*
212          * Missing unreachable object? Ignore it. It's not like
213          * we miss it (since it can't be reached), nor do we want
214          * to complain about it being unreachable (since it does
215          * not exist).
216          */
217         if (!obj->parsed)
218                 return;
219
220         /*
221          * Unreachable object that exists? Show it if asked to,
222          * since this is something that is prunable.
223          */
224         if (show_unreachable) {
225                 printf("unreachable %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
226                 return;
227         }
228
229         /*
230          * "!used" means that nothing at all points to it, including
231          * other unreachable objects. In other words, it's the "tip"
232          * of some set of unreachable objects, usually a commit that
233          * got dropped.
234          *
235          * Such starting points are more interesting than some random
236          * set of unreachable objects, so we show them even if the user
237          * hasn't asked for _all_ unreachable objects. If you have
238          * deleted a branch by mistake, this is a prime candidate to
239          * start looking at, for example.
240          */
241         if (!obj->used) {
242                 if (show_dangling)
243                         printf("dangling %s %s\n", typename(obj->type),
244                                sha1_to_hex(obj->sha1));
245                 if (write_lost_and_found) {
246                         char *filename = git_pathdup("lost-found/%s/%s",
247                                 obj->type == OBJ_COMMIT ? "commit" : "other",
248                                 sha1_to_hex(obj->sha1));
249                         FILE *f;
250
251                         if (safe_create_leading_directories_const(filename)) {
252                                 error("Could not create lost-found");
253                                 free(filename);
254                                 return;
255                         }
256                         if (!(f = fopen(filename, "w")))
257                                 die_errno("Could not open '%s'", filename);
258                         if (obj->type == OBJ_BLOB) {
259                                 if (stream_blob_to_fd(fileno(f), obj->sha1, NULL, 1))
260                                         die_errno("Could not write '%s'", filename);
261                         } else
262                                 fprintf(f, "%s\n", sha1_to_hex(obj->sha1));
263                         if (fclose(f))
264                                 die_errno("Could not finish '%s'",
265                                           filename);
266                         free(filename);
267                 }
268                 return;
269         }
270
271         /*
272          * Otherwise? It's there, it's unreachable, and some other unreachable
273          * object points to it. Ignore it - it's not interesting, and we showed
274          * all the interesting cases above.
275          */
276 }
277
278 static void check_object(struct object *obj)
279 {
280         if (verbose)
281                 fprintf(stderr, "Checking %s\n", sha1_to_hex(obj->sha1));
282
283         if (obj->flags & REACHABLE)
284                 check_reachable_object(obj);
285         else
286                 check_unreachable_object(obj);
287 }
288
289 static void check_connectivity(void)
290 {
291         int i, max;
292
293         /* Traverse the pending reachable objects */
294         traverse_reachable();
295
296         /* Look up all the requirements, warn about missing objects.. */
297         max = get_max_object_index();
298         if (verbose)
299                 fprintf(stderr, "Checking connectivity (%d objects)\n", max);
300
301         for (i = 0; i < max; i++) {
302                 struct object *obj = get_indexed_object(i);
303
304                 if (obj)
305                         check_object(obj);
306         }
307 }
308
309 static int fsck_obj(struct object *obj)
310 {
311         if (obj->flags & SEEN)
312                 return 0;
313         obj->flags |= SEEN;
314
315         if (verbose)
316                 fprintf(stderr, "Checking %s %s\n",
317                         typename(obj->type), sha1_to_hex(obj->sha1));
318
319         if (fsck_walk(obj, NULL, &fsck_obj_options))
320                 objerror(obj, "broken links");
321         if (fsck_object(obj, NULL, 0, &fsck_obj_options))
322                 return -1;
323
324         if (obj->type == OBJ_TREE) {
325                 struct tree *item = (struct tree *) obj;
326
327                 free_tree_buffer(item);
328         }
329
330         if (obj->type == OBJ_COMMIT) {
331                 struct commit *commit = (struct commit *) obj;
332
333                 free_commit_buffer(commit);
334
335                 if (!commit->parents && show_root)
336                         printf("root %s\n", sha1_to_hex(commit->object.sha1));
337         }
338
339         if (obj->type == OBJ_TAG) {
340                 struct tag *tag = (struct tag *) obj;
341
342                 if (show_tags && tag->tagged) {
343                         printf("tagged %s %s", typename(tag->tagged->type), sha1_to_hex(tag->tagged->sha1));
344                         printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
345                 }
346         }
347
348         return 0;
349 }
350
351 static int fsck_sha1(const unsigned char *sha1)
352 {
353         struct object *obj = parse_object(sha1);
354         if (!obj) {
355                 errors_found |= ERROR_OBJECT;
356                 return error("%s: object corrupt or missing",
357                              sha1_to_hex(sha1));
358         }
359         obj->flags |= HAS_OBJ;
360         return fsck_obj(obj);
361 }
362
363 static int fsck_obj_buffer(const unsigned char *sha1, enum object_type type,
364                            unsigned long size, void *buffer, int *eaten)
365 {
366         struct object *obj;
367         obj = parse_object_buffer(sha1, type, size, buffer, eaten);
368         if (!obj) {
369                 errors_found |= ERROR_OBJECT;
370                 return error("%s: object corrupt or missing", sha1_to_hex(sha1));
371         }
372         obj->flags = HAS_OBJ;
373         return fsck_obj(obj);
374 }
375
376 /*
377  * This is the sorting chunk size: make it reasonably
378  * big so that we can sort well..
379  */
380 #define MAX_SHA1_ENTRIES (1024)
381
382 struct sha1_entry {
383         unsigned long ino;
384         unsigned char sha1[20];
385 };
386
387 static struct {
388         unsigned long nr;
389         struct sha1_entry *entry[MAX_SHA1_ENTRIES];
390 } sha1_list;
391
392 static int ino_compare(const void *_a, const void *_b)
393 {
394         const struct sha1_entry *a = _a, *b = _b;
395         unsigned long ino1 = a->ino, ino2 = b->ino;
396         return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
397 }
398
399 static void fsck_sha1_list(void)
400 {
401         int i, nr = sha1_list.nr;
402
403         if (SORT_DIRENT)
404                 qsort(sha1_list.entry, nr,
405                       sizeof(struct sha1_entry *), ino_compare);
406         for (i = 0; i < nr; i++) {
407                 struct sha1_entry *entry = sha1_list.entry[i];
408                 unsigned char *sha1 = entry->sha1;
409
410                 sha1_list.entry[i] = NULL;
411                 if (fsck_sha1(sha1))
412                         errors_found |= ERROR_OBJECT;
413                 free(entry);
414         }
415         sha1_list.nr = 0;
416 }
417
418 static void add_sha1_list(unsigned char *sha1, unsigned long ino)
419 {
420         struct sha1_entry *entry = xmalloc(sizeof(*entry));
421         int nr;
422
423         entry->ino = ino;
424         hashcpy(entry->sha1, sha1);
425         nr = sha1_list.nr;
426         if (nr == MAX_SHA1_ENTRIES) {
427                 fsck_sha1_list();
428                 nr = 0;
429         }
430         sha1_list.entry[nr] = entry;
431         sha1_list.nr = ++nr;
432 }
433
434 static inline int is_loose_object_file(struct dirent *de,
435                                        char *name, unsigned char *sha1)
436 {
437         if (strlen(de->d_name) != 38)
438                 return 0;
439         memcpy(name + 2, de->d_name, 39);
440         return !get_sha1_hex(name, sha1);
441 }
442
443 static void fsck_dir(int i, char *path)
444 {
445         DIR *dir = opendir(path);
446         struct dirent *de;
447         char name[100];
448
449         if (!dir)
450                 return;
451
452         if (verbose)
453                 fprintf(stderr, "Checking directory %s\n", path);
454
455         sprintf(name, "%02x", i);
456         while ((de = readdir(dir)) != NULL) {
457                 unsigned char sha1[20];
458
459                 if (is_dot_or_dotdot(de->d_name))
460                         continue;
461                 if (is_loose_object_file(de, name, sha1)) {
462                         add_sha1_list(sha1, DIRENT_SORT_HINT(de));
463                         continue;
464                 }
465                 if (starts_with(de->d_name, "tmp_obj_"))
466                         continue;
467                 fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
468         }
469         closedir(dir);
470 }
471
472 static int default_refs;
473
474 static void fsck_handle_reflog_sha1(const char *refname, unsigned char *sha1)
475 {
476         struct object *obj;
477
478         if (!is_null_sha1(sha1)) {
479                 obj = lookup_object(sha1);
480                 if (obj) {
481                         obj->used = 1;
482                         mark_object_reachable(obj);
483                 } else {
484                         error("%s: invalid reflog entry %s", refname, sha1_to_hex(sha1));
485                         errors_found |= ERROR_REACHABLE;
486                 }
487         }
488 }
489
490 static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
491                 const char *email, unsigned long timestamp, int tz,
492                 const char *message, void *cb_data)
493 {
494         const char *refname = cb_data;
495
496         if (verbose)
497                 fprintf(stderr, "Checking reflog %s->%s\n",
498                         sha1_to_hex(osha1), sha1_to_hex(nsha1));
499
500         fsck_handle_reflog_sha1(refname, osha1);
501         fsck_handle_reflog_sha1(refname, nsha1);
502         return 0;
503 }
504
505 static int fsck_handle_reflog(const char *logname, const struct object_id *oid,
506                               int flag, void *cb_data)
507 {
508         for_each_reflog_ent(logname, fsck_handle_reflog_ent, (void *)logname);
509         return 0;
510 }
511
512 static int fsck_handle_ref(const char *refname, const struct object_id *oid,
513                            int flag, void *cb_data)
514 {
515         struct object *obj;
516
517         obj = parse_object(oid->hash);
518         if (!obj) {
519                 error("%s: invalid sha1 pointer %s", refname, oid_to_hex(oid));
520                 errors_found |= ERROR_REACHABLE;
521                 /* We'll continue with the rest despite the error.. */
522                 return 0;
523         }
524         if (obj->type != OBJ_COMMIT && is_branch(refname))
525                 error("%s: not a commit", refname);
526         default_refs++;
527         obj->used = 1;
528         mark_object_reachable(obj);
529
530         return 0;
531 }
532
533 static void get_default_heads(void)
534 {
535         if (head_points_at && !is_null_oid(&head_oid))
536                 fsck_handle_ref("HEAD", &head_oid, 0, NULL);
537         for_each_rawref(fsck_handle_ref, NULL);
538         if (include_reflogs)
539                 for_each_reflog(fsck_handle_reflog, NULL);
540
541         /*
542          * Not having any default heads isn't really fatal, but
543          * it does mean that "--unreachable" no longer makes any
544          * sense (since in this case everything will obviously
545          * be unreachable by definition.
546          *
547          * Showing dangling objects is valid, though (as those
548          * dangling objects are likely lost heads).
549          *
550          * So we just print a warning about it, and clear the
551          * "show_unreachable" flag.
552          */
553         if (!default_refs) {
554                 fprintf(stderr, "notice: No default references\n");
555                 show_unreachable = 0;
556         }
557 }
558
559 static void fsck_object_dir(const char *path)
560 {
561         int i;
562         struct progress *progress = NULL;
563
564         if (verbose)
565                 fprintf(stderr, "Checking object directory\n");
566
567         if (show_progress)
568                 progress = start_progress(_("Checking object directories"), 256);
569         for (i = 0; i < 256; i++) {
570                 static char dir[4096];
571                 sprintf(dir, "%s/%02x", path, i);
572                 fsck_dir(i, dir);
573                 display_progress(progress, i+1);
574         }
575         stop_progress(&progress);
576         fsck_sha1_list();
577 }
578
579 static int fsck_head_link(void)
580 {
581         int flag;
582         int null_is_error = 0;
583
584         if (verbose)
585                 fprintf(stderr, "Checking HEAD link\n");
586
587         head_points_at = resolve_ref_unsafe("HEAD", 0, head_oid.hash, &flag);
588         if (!head_points_at)
589                 return error("Invalid HEAD");
590         if (!strcmp(head_points_at, "HEAD"))
591                 /* detached HEAD */
592                 null_is_error = 1;
593         else if (!starts_with(head_points_at, "refs/heads/"))
594                 return error("HEAD points to something strange (%s)",
595                              head_points_at);
596         if (is_null_oid(&head_oid)) {
597                 if (null_is_error)
598                         return error("HEAD: detached HEAD points at nothing");
599                 fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
600                         head_points_at + 11);
601         }
602         return 0;
603 }
604
605 static int fsck_cache_tree(struct cache_tree *it)
606 {
607         int i;
608         int err = 0;
609
610         if (verbose)
611                 fprintf(stderr, "Checking cache tree\n");
612
613         if (0 <= it->entry_count) {
614                 struct object *obj = parse_object(it->sha1);
615                 if (!obj) {
616                         error("%s: invalid sha1 pointer in cache-tree",
617                               sha1_to_hex(it->sha1));
618                         return 1;
619                 }
620                 obj->used = 1;
621                 mark_object_reachable(obj);
622                 if (obj->type != OBJ_TREE)
623                         err |= objerror(obj, "non-tree in cache-tree");
624         }
625         for (i = 0; i < it->subtree_nr; i++)
626                 err |= fsck_cache_tree(it->down[i]->cache_tree);
627         return err;
628 }
629
630 static char const * const fsck_usage[] = {
631         N_("git fsck [<options>] [<object>...]"),
632         NULL
633 };
634
635 static struct option fsck_opts[] = {
636         OPT__VERBOSE(&verbose, N_("be verbose")),
637         OPT_BOOL(0, "unreachable", &show_unreachable, N_("show unreachable objects")),
638         OPT_BOOL(0, "dangling", &show_dangling, N_("show dangling objects")),
639         OPT_BOOL(0, "tags", &show_tags, N_("report tags")),
640         OPT_BOOL(0, "root", &show_root, N_("report root nodes")),
641         OPT_BOOL(0, "cache", &keep_cache_objects, N_("make index objects head nodes")),
642         OPT_BOOL(0, "reflogs", &include_reflogs, N_("make reflogs head nodes (default)")),
643         OPT_BOOL(0, "full", &check_full, N_("also consider packs and alternate objects")),
644         OPT_BOOL(0, "connectivity-only", &connectivity_only, N_("check only connectivity")),
645         OPT_BOOL(0, "strict", &check_strict, N_("enable more strict checking")),
646         OPT_BOOL(0, "lost-found", &write_lost_and_found,
647                                 N_("write dangling objects in .git/lost-found")),
648         OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
649         OPT_END(),
650 };
651
652 int cmd_fsck(int argc, const char **argv, const char *prefix)
653 {
654         int i, heads;
655         struct alternate_object_database *alt;
656
657         errors_found = 0;
658         check_replace_refs = 0;
659
660         argc = parse_options(argc, argv, prefix, fsck_opts, fsck_usage, 0);
661
662         fsck_walk_options.walk = mark_object;
663         fsck_obj_options.walk = mark_used;
664         fsck_obj_options.error_func = fsck_error_func;
665         if (check_strict)
666                 fsck_obj_options.strict = 1;
667
668         if (show_progress == -1)
669                 show_progress = isatty(2);
670         if (verbose)
671                 show_progress = 0;
672
673         if (write_lost_and_found) {
674                 check_full = 1;
675                 include_reflogs = 0;
676         }
677
678         git_config(fsck_config, NULL);
679
680         fsck_head_link();
681         if (!connectivity_only)
682                 fsck_object_dir(get_object_directory());
683
684         prepare_alt_odb();
685         for (alt = alt_odb_list; alt; alt = alt->next) {
686                 char namebuf[PATH_MAX];
687                 int namelen = alt->name - alt->base;
688                 memcpy(namebuf, alt->base, namelen);
689                 namebuf[namelen - 1] = 0;
690                 fsck_object_dir(namebuf);
691         }
692
693         if (check_full) {
694                 struct packed_git *p;
695                 uint32_t total = 0, count = 0;
696                 struct progress *progress = NULL;
697
698                 prepare_packed_git();
699
700                 if (show_progress) {
701                         for (p = packed_git; p; p = p->next) {
702                                 if (open_pack_index(p))
703                                         continue;
704                                 total += p->num_objects;
705                         }
706
707                         progress = start_progress(_("Checking objects"), total);
708                 }
709                 for (p = packed_git; p; p = p->next) {
710                         /* verify gives error messages itself */
711                         if (verify_pack(p, fsck_obj_buffer,
712                                         progress, count))
713                                 errors_found |= ERROR_PACK;
714                         count += p->num_objects;
715                 }
716                 stop_progress(&progress);
717         }
718
719         heads = 0;
720         for (i = 0; i < argc; i++) {
721                 const char *arg = argv[i];
722                 unsigned char sha1[20];
723                 if (!get_sha1(arg, sha1)) {
724                         struct object *obj = lookup_object(sha1);
725
726                         /* Error is printed by lookup_object(). */
727                         if (!obj)
728                                 continue;
729
730                         obj->used = 1;
731                         mark_object_reachable(obj);
732                         heads++;
733                         continue;
734                 }
735                 error("invalid parameter: expected sha1, got '%s'", arg);
736         }
737
738         /*
739          * If we've not been given any explicit head information, do the
740          * default ones from .git/refs. We also consider the index file
741          * in this case (ie this implies --cache).
742          */
743         if (!heads) {
744                 get_default_heads();
745                 keep_cache_objects = 1;
746         }
747
748         if (keep_cache_objects) {
749                 read_cache();
750                 for (i = 0; i < active_nr; i++) {
751                         unsigned int mode;
752                         struct blob *blob;
753                         struct object *obj;
754
755                         mode = active_cache[i]->ce_mode;
756                         if (S_ISGITLINK(mode))
757                                 continue;
758                         blob = lookup_blob(active_cache[i]->sha1);
759                         if (!blob)
760                                 continue;
761                         obj = &blob->object;
762                         obj->used = 1;
763                         mark_object_reachable(obj);
764                 }
765                 if (active_cache_tree)
766                         fsck_cache_tree(active_cache_tree);
767         }
768
769         check_connectivity();
770         return errors_found;
771 }