Merge branch 'en/rebase-against-rebase-fix'
[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
15 #define REACHABLE 0x0001
16 #define SEEN      0x0002
17
18 static int show_root;
19 static int show_tags;
20 static int show_unreachable;
21 static int include_reflogs = 1;
22 static int check_full = 1;
23 static int check_strict;
24 static int keep_cache_objects;
25 static unsigned char head_sha1[20];
26 static const char *head_points_at;
27 static int errors_found;
28 static int write_lost_and_found;
29 static int verbose;
30 #define ERROR_OBJECT 01
31 #define ERROR_REACHABLE 02
32
33 #ifdef NO_D_INO_IN_DIRENT
34 #define SORT_DIRENT 0
35 #define DIRENT_SORT_HINT(de) 0
36 #else
37 #define SORT_DIRENT 1
38 #define DIRENT_SORT_HINT(de) ((de)->d_ino)
39 #endif
40
41 static void objreport(struct object *obj, const char *severity,
42                       const char *err, va_list params)
43 {
44         fprintf(stderr, "%s in %s %s: ",
45                 severity, typename(obj->type), sha1_to_hex(obj->sha1));
46         vfprintf(stderr, err, params);
47         fputs("\n", stderr);
48 }
49
50 __attribute__((format (printf, 2, 3)))
51 static int objerror(struct object *obj, const char *err, ...)
52 {
53         va_list params;
54         va_start(params, err);
55         errors_found |= ERROR_OBJECT;
56         objreport(obj, "error", err, params);
57         va_end(params);
58         return -1;
59 }
60
61 __attribute__((format (printf, 3, 4)))
62 static int fsck_error_func(struct object *obj, int type, const char *err, ...)
63 {
64         va_list params;
65         va_start(params, err);
66         objreport(obj, (type == FSCK_WARN) ? "warning" : "error", err, params);
67         va_end(params);
68         return (type == FSCK_WARN) ? 0 : 1;
69 }
70
71 static struct object_array pending;
72
73 static int mark_object(struct object *obj, int type, void *data)
74 {
75         struct object *parent = data;
76
77         if (!obj) {
78                 printf("broken link from %7s %s\n",
79                            typename(parent->type), sha1_to_hex(parent->sha1));
80                 printf("broken link from %7s %s\n",
81                            (type == OBJ_ANY ? "unknown" : typename(type)), "unknown");
82                 errors_found |= ERROR_REACHABLE;
83                 return 1;
84         }
85
86         if (type != OBJ_ANY && obj->type != type)
87                 objerror(parent, "wrong object type in link");
88
89         if (obj->flags & REACHABLE)
90                 return 0;
91         obj->flags |= REACHABLE;
92         if (!obj->parsed) {
93                 if (parent && !has_sha1_file(obj->sha1)) {
94                         printf("broken link from %7s %s\n",
95                                  typename(parent->type), sha1_to_hex(parent->sha1));
96                         printf("              to %7s %s\n",
97                                  typename(obj->type), sha1_to_hex(obj->sha1));
98                         errors_found |= ERROR_REACHABLE;
99                 }
100                 return 1;
101         }
102
103         add_object_array(obj, (void *) parent, &pending);
104         return 0;
105 }
106
107 static void mark_object_reachable(struct object *obj)
108 {
109         mark_object(obj, OBJ_ANY, NULL);
110 }
111
112 static int traverse_one_object(struct object *obj, struct object *parent)
113 {
114         int result;
115         struct tree *tree = NULL;
116
117         if (obj->type == OBJ_TREE) {
118                 obj->parsed = 0;
119                 tree = (struct tree *)obj;
120                 if (parse_tree(tree) < 0)
121                         return 1; /* error already displayed */
122         }
123         result = fsck_walk(obj, mark_object, obj);
124         if (tree) {
125                 free(tree->buffer);
126                 tree->buffer = NULL;
127         }
128         return result;
129 }
130
131 static int traverse_reachable(void)
132 {
133         int result = 0;
134         while (pending.nr) {
135                 struct object_array_entry *entry;
136                 struct object *obj, *parent;
137
138                 entry = pending.objects + --pending.nr;
139                 obj = entry->item;
140                 parent = (struct object *) entry->name;
141                 result |= traverse_one_object(obj, parent);
142         }
143         return !!result;
144 }
145
146 static int mark_used(struct object *obj, int type, void *data)
147 {
148         if (!obj)
149                 return 1;
150         obj->used = 1;
151         return 0;
152 }
153
154 /*
155  * Check a single reachable object
156  */
157 static void check_reachable_object(struct object *obj)
158 {
159         /*
160          * We obviously want the object to be parsed,
161          * except if it was in a pack-file and we didn't
162          * do a full fsck
163          */
164         if (!obj->parsed) {
165                 if (has_sha1_pack(obj->sha1))
166                         return; /* it is in pack - forget about it */
167                 printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
168                 errors_found |= ERROR_REACHABLE;
169                 return;
170         }
171 }
172
173 /*
174  * Check a single unreachable object
175  */
176 static void check_unreachable_object(struct object *obj)
177 {
178         /*
179          * Missing unreachable object? Ignore it. It's not like
180          * we miss it (since it can't be reached), nor do we want
181          * to complain about it being unreachable (since it does
182          * not exist).
183          */
184         if (!obj->parsed)
185                 return;
186
187         /*
188          * Unreachable object that exists? Show it if asked to,
189          * since this is something that is prunable.
190          */
191         if (show_unreachable) {
192                 printf("unreachable %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
193                 return;
194         }
195
196         /*
197          * "!used" means that nothing at all points to it, including
198          * other unreachable objects. In other words, it's the "tip"
199          * of some set of unreachable objects, usually a commit that
200          * got dropped.
201          *
202          * Such starting points are more interesting than some random
203          * set of unreachable objects, so we show them even if the user
204          * hasn't asked for _all_ unreachable objects. If you have
205          * deleted a branch by mistake, this is a prime candidate to
206          * start looking at, for example.
207          */
208         if (!obj->used) {
209                 printf("dangling %s %s\n", typename(obj->type),
210                        sha1_to_hex(obj->sha1));
211                 if (write_lost_and_found) {
212                         char *filename = git_path("lost-found/%s/%s",
213                                 obj->type == OBJ_COMMIT ? "commit" : "other",
214                                 sha1_to_hex(obj->sha1));
215                         FILE *f;
216
217                         if (safe_create_leading_directories(filename)) {
218                                 error("Could not create lost-found");
219                                 return;
220                         }
221                         if (!(f = fopen(filename, "w")))
222                                 die_errno("Could not open '%s'", filename);
223                         if (obj->type == OBJ_BLOB) {
224                                 enum object_type type;
225                                 unsigned long size;
226                                 char *buf = read_sha1_file(obj->sha1,
227                                                 &type, &size);
228                                 if (buf) {
229                                         if (fwrite(buf, size, 1, f) != 1)
230                                                 die_errno("Could not write '%s'",
231                                                           filename);
232                                         free(buf);
233                                 }
234                         } else
235                                 fprintf(f, "%s\n", sha1_to_hex(obj->sha1));
236                         if (fclose(f))
237                                 die_errno("Could not finish '%s'",
238                                           filename);
239                 }
240                 return;
241         }
242
243         /*
244          * Otherwise? It's there, it's unreachable, and some other unreachable
245          * object points to it. Ignore it - it's not interesting, and we showed
246          * all the interesting cases above.
247          */
248 }
249
250 static void check_object(struct object *obj)
251 {
252         if (verbose)
253                 fprintf(stderr, "Checking %s\n", sha1_to_hex(obj->sha1));
254
255         if (obj->flags & REACHABLE)
256                 check_reachable_object(obj);
257         else
258                 check_unreachable_object(obj);
259 }
260
261 static void check_connectivity(void)
262 {
263         int i, max;
264
265         /* Traverse the pending reachable objects */
266         traverse_reachable();
267
268         /* Look up all the requirements, warn about missing objects.. */
269         max = get_max_object_index();
270         if (verbose)
271                 fprintf(stderr, "Checking connectivity (%d objects)\n", max);
272
273         for (i = 0; i < max; i++) {
274                 struct object *obj = get_indexed_object(i);
275
276                 if (obj)
277                         check_object(obj);
278         }
279 }
280
281 static int fsck_sha1(const unsigned char *sha1)
282 {
283         struct object *obj = parse_object(sha1);
284         if (!obj) {
285                 errors_found |= ERROR_OBJECT;
286                 return error("%s: object corrupt or missing",
287                              sha1_to_hex(sha1));
288         }
289         if (obj->flags & SEEN)
290                 return 0;
291         obj->flags |= SEEN;
292
293         if (verbose)
294                 fprintf(stderr, "Checking %s %s\n",
295                         typename(obj->type), sha1_to_hex(obj->sha1));
296
297         if (fsck_walk(obj, mark_used, NULL))
298                 objerror(obj, "broken links");
299         if (fsck_object(obj, check_strict, fsck_error_func))
300                 return -1;
301
302         if (obj->type == OBJ_TREE) {
303                 struct tree *item = (struct tree *) obj;
304
305                 free(item->buffer);
306                 item->buffer = NULL;
307         }
308
309         if (obj->type == OBJ_COMMIT) {
310                 struct commit *commit = (struct commit *) obj;
311
312                 free(commit->buffer);
313                 commit->buffer = NULL;
314
315                 if (!commit->parents && show_root)
316                         printf("root %s\n", sha1_to_hex(commit->object.sha1));
317         }
318
319         if (obj->type == OBJ_TAG) {
320                 struct tag *tag = (struct tag *) obj;
321
322                 if (show_tags && tag->tagged) {
323                         printf("tagged %s %s", typename(tag->tagged->type), sha1_to_hex(tag->tagged->sha1));
324                         printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
325                 }
326         }
327
328         return 0;
329 }
330
331 /*
332  * This is the sorting chunk size: make it reasonably
333  * big so that we can sort well..
334  */
335 #define MAX_SHA1_ENTRIES (1024)
336
337 struct sha1_entry {
338         unsigned long ino;
339         unsigned char sha1[20];
340 };
341
342 static struct {
343         unsigned long nr;
344         struct sha1_entry *entry[MAX_SHA1_ENTRIES];
345 } sha1_list;
346
347 static int ino_compare(const void *_a, const void *_b)
348 {
349         const struct sha1_entry *a = _a, *b = _b;
350         unsigned long ino1 = a->ino, ino2 = b->ino;
351         return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
352 }
353
354 static void fsck_sha1_list(void)
355 {
356         int i, nr = sha1_list.nr;
357
358         if (SORT_DIRENT)
359                 qsort(sha1_list.entry, nr,
360                       sizeof(struct sha1_entry *), ino_compare);
361         for (i = 0; i < nr; i++) {
362                 struct sha1_entry *entry = sha1_list.entry[i];
363                 unsigned char *sha1 = entry->sha1;
364
365                 sha1_list.entry[i] = NULL;
366                 fsck_sha1(sha1);
367                 free(entry);
368         }
369         sha1_list.nr = 0;
370 }
371
372 static void add_sha1_list(unsigned char *sha1, unsigned long ino)
373 {
374         struct sha1_entry *entry = xmalloc(sizeof(*entry));
375         int nr;
376
377         entry->ino = ino;
378         hashcpy(entry->sha1, sha1);
379         nr = sha1_list.nr;
380         if (nr == MAX_SHA1_ENTRIES) {
381                 fsck_sha1_list();
382                 nr = 0;
383         }
384         sha1_list.entry[nr] = entry;
385         sha1_list.nr = ++nr;
386 }
387
388 static void fsck_dir(int i, char *path)
389 {
390         DIR *dir = opendir(path);
391         struct dirent *de;
392
393         if (!dir)
394                 return;
395
396         if (verbose)
397                 fprintf(stderr, "Checking directory %s\n", path);
398
399         while ((de = readdir(dir)) != NULL) {
400                 char name[100];
401                 unsigned char sha1[20];
402
403                 if (is_dot_or_dotdot(de->d_name))
404                         continue;
405                 if (strlen(de->d_name) == 38) {
406                         sprintf(name, "%02x", i);
407                         memcpy(name+2, de->d_name, 39);
408                         if (get_sha1_hex(name, sha1) < 0)
409                                 break;
410                         add_sha1_list(sha1, DIRENT_SORT_HINT(de));
411                         continue;
412                 }
413                 if (!prefixcmp(de->d_name, "tmp_obj_"))
414                         continue;
415                 fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
416         }
417         closedir(dir);
418 }
419
420 static int default_refs;
421
422 static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
423                 const char *email, unsigned long timestamp, int tz,
424                 const char *message, void *cb_data)
425 {
426         struct object *obj;
427
428         if (verbose)
429                 fprintf(stderr, "Checking reflog %s->%s\n",
430                         sha1_to_hex(osha1), sha1_to_hex(nsha1));
431
432         if (!is_null_sha1(osha1)) {
433                 obj = lookup_object(osha1);
434                 if (obj) {
435                         obj->used = 1;
436                         mark_object_reachable(obj);
437                 }
438         }
439         obj = lookup_object(nsha1);
440         if (obj) {
441                 obj->used = 1;
442                 mark_object_reachable(obj);
443         }
444         return 0;
445 }
446
447 static int fsck_handle_reflog(const char *logname, const unsigned char *sha1, int flag, void *cb_data)
448 {
449         for_each_reflog_ent(logname, fsck_handle_reflog_ent, NULL);
450         return 0;
451 }
452
453 static int is_branch(const char *refname)
454 {
455         return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
456 }
457
458 static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
459 {
460         struct object *obj;
461
462         obj = parse_object(sha1);
463         if (!obj) {
464                 error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
465                 /* We'll continue with the rest despite the error.. */
466                 return 0;
467         }
468         if (obj->type != OBJ_COMMIT && is_branch(refname))
469                 error("%s: not a commit", refname);
470         default_refs++;
471         obj->used = 1;
472         mark_object_reachable(obj);
473
474         return 0;
475 }
476
477 static void get_default_heads(void)
478 {
479         if (head_points_at && !is_null_sha1(head_sha1))
480                 fsck_handle_ref("HEAD", head_sha1, 0, NULL);
481         for_each_ref(fsck_handle_ref, NULL);
482         if (include_reflogs)
483                 for_each_reflog(fsck_handle_reflog, NULL);
484
485         /*
486          * Not having any default heads isn't really fatal, but
487          * it does mean that "--unreachable" no longer makes any
488          * sense (since in this case everything will obviously
489          * be unreachable by definition.
490          *
491          * Showing dangling objects is valid, though (as those
492          * dangling objects are likely lost heads).
493          *
494          * So we just print a warning about it, and clear the
495          * "show_unreachable" flag.
496          */
497         if (!default_refs) {
498                 fprintf(stderr, "notice: No default references\n");
499                 show_unreachable = 0;
500         }
501 }
502
503 static void fsck_object_dir(const char *path)
504 {
505         int i;
506
507         if (verbose)
508                 fprintf(stderr, "Checking object directory\n");
509
510         for (i = 0; i < 256; i++) {
511                 static char dir[4096];
512                 sprintf(dir, "%s/%02x", path, i);
513                 fsck_dir(i, dir);
514         }
515         fsck_sha1_list();
516 }
517
518 static int fsck_head_link(void)
519 {
520         int flag;
521         int null_is_error = 0;
522
523         if (verbose)
524                 fprintf(stderr, "Checking HEAD link\n");
525
526         head_points_at = resolve_ref("HEAD", head_sha1, 0, &flag);
527         if (!head_points_at)
528                 return error("Invalid HEAD");
529         if (!strcmp(head_points_at, "HEAD"))
530                 /* detached HEAD */
531                 null_is_error = 1;
532         else if (prefixcmp(head_points_at, "refs/heads/"))
533                 return error("HEAD points to something strange (%s)",
534                              head_points_at);
535         if (is_null_sha1(head_sha1)) {
536                 if (null_is_error)
537                         return error("HEAD: detached HEAD points at nothing");
538                 fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
539                         head_points_at + 11);
540         }
541         return 0;
542 }
543
544 static int fsck_cache_tree(struct cache_tree *it)
545 {
546         int i;
547         int err = 0;
548
549         if (verbose)
550                 fprintf(stderr, "Checking cache tree\n");
551
552         if (0 <= it->entry_count) {
553                 struct object *obj = parse_object(it->sha1);
554                 if (!obj) {
555                         error("%s: invalid sha1 pointer in cache-tree",
556                               sha1_to_hex(it->sha1));
557                         return 1;
558                 }
559                 mark_object_reachable(obj);
560                 obj->used = 1;
561                 if (obj->type != OBJ_TREE)
562                         err |= objerror(obj, "non-tree in cache-tree");
563         }
564         for (i = 0; i < it->subtree_nr; i++)
565                 err |= fsck_cache_tree(it->down[i]->cache_tree);
566         return err;
567 }
568
569 static char const * const fsck_usage[] = {
570         "git fsck [options] [<object>...]",
571         NULL
572 };
573
574 static struct option fsck_opts[] = {
575         OPT__VERBOSE(&verbose),
576         OPT_BOOLEAN(0, "unreachable", &show_unreachable, "show unreachable objects"),
577         OPT_BOOLEAN(0, "tags", &show_tags, "report tags"),
578         OPT_BOOLEAN(0, "root", &show_root, "report root nodes"),
579         OPT_BOOLEAN(0, "cache", &keep_cache_objects, "make index objects head nodes"),
580         OPT_BOOLEAN(0, "reflogs", &include_reflogs, "make reflogs head nodes (default)"),
581         OPT_BOOLEAN(0, "full", &check_full, "also consider packs and alternate objects"),
582         OPT_BOOLEAN(0, "strict", &check_strict, "enable more strict checking"),
583         OPT_BOOLEAN(0, "lost-found", &write_lost_and_found,
584                                 "write dangling objects in .git/lost-found"),
585         OPT_END(),
586 };
587
588 int cmd_fsck(int argc, const char **argv, const char *prefix)
589 {
590         int i, heads;
591         struct alternate_object_database *alt;
592
593         errors_found = 0;
594         read_replace_refs = 0;
595
596         argc = parse_options(argc, argv, prefix, fsck_opts, fsck_usage, 0);
597         if (write_lost_and_found) {
598                 check_full = 1;
599                 include_reflogs = 0;
600         }
601
602         fsck_head_link();
603         fsck_object_dir(get_object_directory());
604
605         prepare_alt_odb();
606         for (alt = alt_odb_list; alt; alt = alt->next) {
607                 char namebuf[PATH_MAX];
608                 int namelen = alt->name - alt->base;
609                 memcpy(namebuf, alt->base, namelen);
610                 namebuf[namelen - 1] = 0;
611                 fsck_object_dir(namebuf);
612         }
613
614         if (check_full) {
615                 struct packed_git *p;
616
617                 prepare_packed_git();
618                 for (p = packed_git; p; p = p->next)
619                         /* verify gives error messages itself */
620                         verify_pack(p);
621
622                 for (p = packed_git; p; p = p->next) {
623                         uint32_t j, num;
624                         if (open_pack_index(p))
625                                 continue;
626                         num = p->num_objects;
627                         for (j = 0; j < num; j++)
628                                 fsck_sha1(nth_packed_object_sha1(p, j));
629                 }
630         }
631
632         heads = 0;
633         for (i = 0; i < argc; i++) {
634                 const char *arg = argv[i];
635                 unsigned char sha1[20];
636                 if (!get_sha1(arg, sha1)) {
637                         struct object *obj = lookup_object(sha1);
638
639                         /* Error is printed by lookup_object(). */
640                         if (!obj)
641                                 continue;
642
643                         obj->used = 1;
644                         mark_object_reachable(obj);
645                         heads++;
646                         continue;
647                 }
648                 error("invalid parameter: expected sha1, got '%s'", arg);
649         }
650
651         /*
652          * If we've not been given any explicit head information, do the
653          * default ones from .git/refs. We also consider the index file
654          * in this case (ie this implies --cache).
655          */
656         if (!heads) {
657                 get_default_heads();
658                 keep_cache_objects = 1;
659         }
660
661         if (keep_cache_objects) {
662                 read_cache();
663                 for (i = 0; i < active_nr; i++) {
664                         unsigned int mode;
665                         struct blob *blob;
666                         struct object *obj;
667
668                         mode = active_cache[i]->ce_mode;
669                         if (S_ISGITLINK(mode))
670                                 continue;
671                         blob = lookup_blob(active_cache[i]->sha1);
672                         if (!blob)
673                                 continue;
674                         obj = &blob->object;
675                         obj->used = 1;
676                         mark_object_reachable(obj);
677                 }
678                 if (active_cache_tree)
679                         fsck_cache_tree(active_cache_tree);
680         }
681
682         check_connectivity();
683         return errors_found;
684 }