Merge branch 'rj/maint-t9159-svn-rev-notation'
[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         /*
78          * The only case data is NULL or type is OBJ_ANY is when
79          * mark_object_reachable() calls us.  All the callers of
80          * that function has non-NULL obj hence ...
81          */
82         if (!obj) {
83                 /* ... these references to parent->fld are safe here */
84                 printf("broken link from %7s %s\n",
85                            typename(parent->type), sha1_to_hex(parent->sha1));
86                 printf("broken link from %7s %s\n",
87                            (type == OBJ_ANY ? "unknown" : typename(type)), "unknown");
88                 errors_found |= ERROR_REACHABLE;
89                 return 1;
90         }
91
92         if (type != OBJ_ANY && obj->type != type)
93                 /* ... and the reference to parent is safe here */
94                 objerror(parent, "wrong object type in link");
95
96         if (obj->flags & REACHABLE)
97                 return 0;
98         obj->flags |= REACHABLE;
99         if (!obj->parsed) {
100                 if (parent && !has_sha1_file(obj->sha1)) {
101                         printf("broken link from %7s %s\n",
102                                  typename(parent->type), sha1_to_hex(parent->sha1));
103                         printf("              to %7s %s\n",
104                                  typename(obj->type), sha1_to_hex(obj->sha1));
105                         errors_found |= ERROR_REACHABLE;
106                 }
107                 return 1;
108         }
109
110         add_object_array(obj, (void *) parent, &pending);
111         return 0;
112 }
113
114 static void mark_object_reachable(struct object *obj)
115 {
116         mark_object(obj, OBJ_ANY, NULL);
117 }
118
119 static int traverse_one_object(struct object *obj)
120 {
121         int result;
122         struct tree *tree = NULL;
123
124         if (obj->type == OBJ_TREE) {
125                 obj->parsed = 0;
126                 tree = (struct tree *)obj;
127                 if (parse_tree(tree) < 0)
128                         return 1; /* error already displayed */
129         }
130         result = fsck_walk(obj, mark_object, obj);
131         if (tree) {
132                 free(tree->buffer);
133                 tree->buffer = NULL;
134         }
135         return result;
136 }
137
138 static int traverse_reachable(void)
139 {
140         int result = 0;
141         while (pending.nr) {
142                 struct object_array_entry *entry;
143                 struct object *obj;
144
145                 entry = pending.objects + --pending.nr;
146                 obj = entry->item;
147                 result |= traverse_one_object(obj);
148         }
149         return !!result;
150 }
151
152 static int mark_used(struct object *obj, int type, void *data)
153 {
154         if (!obj)
155                 return 1;
156         obj->used = 1;
157         return 0;
158 }
159
160 /*
161  * Check a single reachable object
162  */
163 static void check_reachable_object(struct object *obj)
164 {
165         /*
166          * We obviously want the object to be parsed,
167          * except if it was in a pack-file and we didn't
168          * do a full fsck
169          */
170         if (!obj->parsed) {
171                 if (has_sha1_pack(obj->sha1))
172                         return; /* it is in pack - forget about it */
173                 printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
174                 errors_found |= ERROR_REACHABLE;
175                 return;
176         }
177 }
178
179 /*
180  * Check a single unreachable object
181  */
182 static void check_unreachable_object(struct object *obj)
183 {
184         /*
185          * Missing unreachable object? Ignore it. It's not like
186          * we miss it (since it can't be reached), nor do we want
187          * to complain about it being unreachable (since it does
188          * not exist).
189          */
190         if (!obj->parsed)
191                 return;
192
193         /*
194          * Unreachable object that exists? Show it if asked to,
195          * since this is something that is prunable.
196          */
197         if (show_unreachable) {
198                 printf("unreachable %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
199                 return;
200         }
201
202         /*
203          * "!used" means that nothing at all points to it, including
204          * other unreachable objects. In other words, it's the "tip"
205          * of some set of unreachable objects, usually a commit that
206          * got dropped.
207          *
208          * Such starting points are more interesting than some random
209          * set of unreachable objects, so we show them even if the user
210          * hasn't asked for _all_ unreachable objects. If you have
211          * deleted a branch by mistake, this is a prime candidate to
212          * start looking at, for example.
213          */
214         if (!obj->used) {
215                 printf("dangling %s %s\n", typename(obj->type),
216                        sha1_to_hex(obj->sha1));
217                 if (write_lost_and_found) {
218                         char *filename = git_path("lost-found/%s/%s",
219                                 obj->type == OBJ_COMMIT ? "commit" : "other",
220                                 sha1_to_hex(obj->sha1));
221                         FILE *f;
222
223                         if (safe_create_leading_directories(filename)) {
224                                 error("Could not create lost-found");
225                                 return;
226                         }
227                         if (!(f = fopen(filename, "w")))
228                                 die_errno("Could not open '%s'", filename);
229                         if (obj->type == OBJ_BLOB) {
230                                 enum object_type type;
231                                 unsigned long size;
232                                 char *buf = read_sha1_file(obj->sha1,
233                                                 &type, &size);
234                                 if (buf && fwrite(buf, 1, size, f) != size)
235                                         die_errno("Could not write '%s'", filename);
236                                 free(buf);
237                         } else
238                                 fprintf(f, "%s\n", sha1_to_hex(obj->sha1));
239                         if (fclose(f))
240                                 die_errno("Could not finish '%s'",
241                                           filename);
242                 }
243                 return;
244         }
245
246         /*
247          * Otherwise? It's there, it's unreachable, and some other unreachable
248          * object points to it. Ignore it - it's not interesting, and we showed
249          * all the interesting cases above.
250          */
251 }
252
253 static void check_object(struct object *obj)
254 {
255         if (verbose)
256                 fprintf(stderr, "Checking %s\n", sha1_to_hex(obj->sha1));
257
258         if (obj->flags & REACHABLE)
259                 check_reachable_object(obj);
260         else
261                 check_unreachable_object(obj);
262 }
263
264 static void check_connectivity(void)
265 {
266         int i, max;
267
268         /* Traverse the pending reachable objects */
269         traverse_reachable();
270
271         /* Look up all the requirements, warn about missing objects.. */
272         max = get_max_object_index();
273         if (verbose)
274                 fprintf(stderr, "Checking connectivity (%d objects)\n", max);
275
276         for (i = 0; i < max; i++) {
277                 struct object *obj = get_indexed_object(i);
278
279                 if (obj)
280                         check_object(obj);
281         }
282 }
283
284 static int fsck_sha1(const unsigned char *sha1)
285 {
286         struct object *obj = parse_object(sha1);
287         if (!obj) {
288                 errors_found |= ERROR_OBJECT;
289                 return error("%s: object corrupt or missing",
290                              sha1_to_hex(sha1));
291         }
292         if (obj->flags & SEEN)
293                 return 0;
294         obj->flags |= SEEN;
295
296         if (verbose)
297                 fprintf(stderr, "Checking %s %s\n",
298                         typename(obj->type), sha1_to_hex(obj->sha1));
299
300         if (fsck_walk(obj, mark_used, NULL))
301                 objerror(obj, "broken links");
302         if (fsck_object(obj, check_strict, fsck_error_func))
303                 return -1;
304
305         if (obj->type == OBJ_TREE) {
306                 struct tree *item = (struct tree *) obj;
307
308                 free(item->buffer);
309                 item->buffer = NULL;
310         }
311
312         if (obj->type == OBJ_COMMIT) {
313                 struct commit *commit = (struct commit *) obj;
314
315                 free(commit->buffer);
316                 commit->buffer = NULL;
317
318                 if (!commit->parents && show_root)
319                         printf("root %s\n", sha1_to_hex(commit->object.sha1));
320         }
321
322         if (obj->type == OBJ_TAG) {
323                 struct tag *tag = (struct tag *) obj;
324
325                 if (show_tags && tag->tagged) {
326                         printf("tagged %s %s", typename(tag->tagged->type), sha1_to_hex(tag->tagged->sha1));
327                         printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
328                 }
329         }
330
331         return 0;
332 }
333
334 /*
335  * This is the sorting chunk size: make it reasonably
336  * big so that we can sort well..
337  */
338 #define MAX_SHA1_ENTRIES (1024)
339
340 struct sha1_entry {
341         unsigned long ino;
342         unsigned char sha1[20];
343 };
344
345 static struct {
346         unsigned long nr;
347         struct sha1_entry *entry[MAX_SHA1_ENTRIES];
348 } sha1_list;
349
350 static int ino_compare(const void *_a, const void *_b)
351 {
352         const struct sha1_entry *a = _a, *b = _b;
353         unsigned long ino1 = a->ino, ino2 = b->ino;
354         return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
355 }
356
357 static void fsck_sha1_list(void)
358 {
359         int i, nr = sha1_list.nr;
360
361         if (SORT_DIRENT)
362                 qsort(sha1_list.entry, nr,
363                       sizeof(struct sha1_entry *), ino_compare);
364         for (i = 0; i < nr; i++) {
365                 struct sha1_entry *entry = sha1_list.entry[i];
366                 unsigned char *sha1 = entry->sha1;
367
368                 sha1_list.entry[i] = NULL;
369                 fsck_sha1(sha1);
370                 free(entry);
371         }
372         sha1_list.nr = 0;
373 }
374
375 static void add_sha1_list(unsigned char *sha1, unsigned long ino)
376 {
377         struct sha1_entry *entry = xmalloc(sizeof(*entry));
378         int nr;
379
380         entry->ino = ino;
381         hashcpy(entry->sha1, sha1);
382         nr = sha1_list.nr;
383         if (nr == MAX_SHA1_ENTRIES) {
384                 fsck_sha1_list();
385                 nr = 0;
386         }
387         sha1_list.entry[nr] = entry;
388         sha1_list.nr = ++nr;
389 }
390
391 static inline int is_loose_object_file(struct dirent *de,
392                                        char *name, unsigned char *sha1)
393 {
394         if (strlen(de->d_name) != 38)
395                 return 0;
396         memcpy(name + 2, de->d_name, 39);
397         return !get_sha1_hex(name, sha1);
398 }
399
400 static void fsck_dir(int i, char *path)
401 {
402         DIR *dir = opendir(path);
403         struct dirent *de;
404         char name[100];
405
406         if (!dir)
407                 return;
408
409         if (verbose)
410                 fprintf(stderr, "Checking directory %s\n", path);
411
412         sprintf(name, "%02x", i);
413         while ((de = readdir(dir)) != NULL) {
414                 unsigned char sha1[20];
415
416                 if (is_dot_or_dotdot(de->d_name))
417                         continue;
418                 if (is_loose_object_file(de, name, sha1)) {
419                         add_sha1_list(sha1, DIRENT_SORT_HINT(de));
420                         continue;
421                 }
422                 if (!prefixcmp(de->d_name, "tmp_obj_"))
423                         continue;
424                 fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
425         }
426         closedir(dir);
427 }
428
429 static int default_refs;
430
431 static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
432                 const char *email, unsigned long timestamp, int tz,
433                 const char *message, void *cb_data)
434 {
435         struct object *obj;
436
437         if (verbose)
438                 fprintf(stderr, "Checking reflog %s->%s\n",
439                         sha1_to_hex(osha1), sha1_to_hex(nsha1));
440
441         if (!is_null_sha1(osha1)) {
442                 obj = lookup_object(osha1);
443                 if (obj) {
444                         obj->used = 1;
445                         mark_object_reachable(obj);
446                 }
447         }
448         obj = lookup_object(nsha1);
449         if (obj) {
450                 obj->used = 1;
451                 mark_object_reachable(obj);
452         }
453         return 0;
454 }
455
456 static int fsck_handle_reflog(const char *logname, const unsigned char *sha1, int flag, void *cb_data)
457 {
458         for_each_reflog_ent(logname, fsck_handle_reflog_ent, NULL);
459         return 0;
460 }
461
462 static int is_branch(const char *refname)
463 {
464         return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
465 }
466
467 static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
468 {
469         struct object *obj;
470
471         obj = parse_object(sha1);
472         if (!obj) {
473                 error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
474                 /* We'll continue with the rest despite the error.. */
475                 return 0;
476         }
477         if (obj->type != OBJ_COMMIT && is_branch(refname))
478                 error("%s: not a commit", refname);
479         default_refs++;
480         obj->used = 1;
481         mark_object_reachable(obj);
482
483         return 0;
484 }
485
486 static void get_default_heads(void)
487 {
488         if (head_points_at && !is_null_sha1(head_sha1))
489                 fsck_handle_ref("HEAD", head_sha1, 0, NULL);
490         for_each_ref(fsck_handle_ref, NULL);
491         if (include_reflogs)
492                 for_each_reflog(fsck_handle_reflog, NULL);
493
494         /*
495          * Not having any default heads isn't really fatal, but
496          * it does mean that "--unreachable" no longer makes any
497          * sense (since in this case everything will obviously
498          * be unreachable by definition.
499          *
500          * Showing dangling objects is valid, though (as those
501          * dangling objects are likely lost heads).
502          *
503          * So we just print a warning about it, and clear the
504          * "show_unreachable" flag.
505          */
506         if (!default_refs) {
507                 fprintf(stderr, "notice: No default references\n");
508                 show_unreachable = 0;
509         }
510 }
511
512 static void fsck_object_dir(const char *path)
513 {
514         int i;
515
516         if (verbose)
517                 fprintf(stderr, "Checking object directory\n");
518
519         for (i = 0; i < 256; i++) {
520                 static char dir[4096];
521                 sprintf(dir, "%s/%02x", path, i);
522                 fsck_dir(i, dir);
523         }
524         fsck_sha1_list();
525 }
526
527 static int fsck_head_link(void)
528 {
529         int flag;
530         int null_is_error = 0;
531
532         if (verbose)
533                 fprintf(stderr, "Checking HEAD link\n");
534
535         head_points_at = resolve_ref("HEAD", head_sha1, 0, &flag);
536         if (!head_points_at)
537                 return error("Invalid HEAD");
538         if (!strcmp(head_points_at, "HEAD"))
539                 /* detached HEAD */
540                 null_is_error = 1;
541         else if (prefixcmp(head_points_at, "refs/heads/"))
542                 return error("HEAD points to something strange (%s)",
543                              head_points_at);
544         if (is_null_sha1(head_sha1)) {
545                 if (null_is_error)
546                         return error("HEAD: detached HEAD points at nothing");
547                 fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
548                         head_points_at + 11);
549         }
550         return 0;
551 }
552
553 static int fsck_cache_tree(struct cache_tree *it)
554 {
555         int i;
556         int err = 0;
557
558         if (verbose)
559                 fprintf(stderr, "Checking cache tree\n");
560
561         if (0 <= it->entry_count) {
562                 struct object *obj = parse_object(it->sha1);
563                 if (!obj) {
564                         error("%s: invalid sha1 pointer in cache-tree",
565                               sha1_to_hex(it->sha1));
566                         return 1;
567                 }
568                 obj->used = 1;
569                 mark_object_reachable(obj);
570                 if (obj->type != OBJ_TREE)
571                         err |= objerror(obj, "non-tree in cache-tree");
572         }
573         for (i = 0; i < it->subtree_nr; i++)
574                 err |= fsck_cache_tree(it->down[i]->cache_tree);
575         return err;
576 }
577
578 static char const * const fsck_usage[] = {
579         "git fsck [options] [<object>...]",
580         NULL
581 };
582
583 static struct option fsck_opts[] = {
584         OPT__VERBOSE(&verbose, "be verbose"),
585         OPT_BOOLEAN(0, "unreachable", &show_unreachable, "show unreachable objects"),
586         OPT_BOOLEAN(0, "tags", &show_tags, "report tags"),
587         OPT_BOOLEAN(0, "root", &show_root, "report root nodes"),
588         OPT_BOOLEAN(0, "cache", &keep_cache_objects, "make index objects head nodes"),
589         OPT_BOOLEAN(0, "reflogs", &include_reflogs, "make reflogs head nodes (default)"),
590         OPT_BOOLEAN(0, "full", &check_full, "also consider packs and alternate objects"),
591         OPT_BOOLEAN(0, "strict", &check_strict, "enable more strict checking"),
592         OPT_BOOLEAN(0, "lost-found", &write_lost_and_found,
593                                 "write dangling objects in .git/lost-found"),
594         OPT_END(),
595 };
596
597 int cmd_fsck(int argc, const char **argv, const char *prefix)
598 {
599         int i, heads;
600         struct alternate_object_database *alt;
601
602         errors_found = 0;
603         read_replace_refs = 0;
604
605         argc = parse_options(argc, argv, prefix, fsck_opts, fsck_usage, 0);
606         if (write_lost_and_found) {
607                 check_full = 1;
608                 include_reflogs = 0;
609         }
610
611         fsck_head_link();
612         fsck_object_dir(get_object_directory());
613
614         prepare_alt_odb();
615         for (alt = alt_odb_list; alt; alt = alt->next) {
616                 char namebuf[PATH_MAX];
617                 int namelen = alt->name - alt->base;
618                 memcpy(namebuf, alt->base, namelen);
619                 namebuf[namelen - 1] = 0;
620                 fsck_object_dir(namebuf);
621         }
622
623         if (check_full) {
624                 struct packed_git *p;
625
626                 prepare_packed_git();
627                 for (p = packed_git; p; p = p->next)
628                         /* verify gives error messages itself */
629                         verify_pack(p);
630
631                 for (p = packed_git; p; p = p->next) {
632                         uint32_t j, num;
633                         if (open_pack_index(p))
634                                 continue;
635                         num = p->num_objects;
636                         for (j = 0; j < num; j++)
637                                 fsck_sha1(nth_packed_object_sha1(p, j));
638                 }
639         }
640
641         heads = 0;
642         for (i = 0; i < argc; i++) {
643                 const char *arg = argv[i];
644                 unsigned char sha1[20];
645                 if (!get_sha1(arg, sha1)) {
646                         struct object *obj = lookup_object(sha1);
647
648                         /* Error is printed by lookup_object(). */
649                         if (!obj)
650                                 continue;
651
652                         obj->used = 1;
653                         mark_object_reachable(obj);
654                         heads++;
655                         continue;
656                 }
657                 error("invalid parameter: expected sha1, got '%s'", arg);
658         }
659
660         /*
661          * If we've not been given any explicit head information, do the
662          * default ones from .git/refs. We also consider the index file
663          * in this case (ie this implies --cache).
664          */
665         if (!heads) {
666                 get_default_heads();
667                 keep_cache_objects = 1;
668         }
669
670         if (keep_cache_objects) {
671                 read_cache();
672                 for (i = 0; i < active_nr; i++) {
673                         unsigned int mode;
674                         struct blob *blob;
675                         struct object *obj;
676
677                         mode = active_cache[i]->ce_mode;
678                         if (S_ISGITLINK(mode))
679                                 continue;
680                         blob = lookup_blob(active_cache[i]->sha1);
681                         if (!blob)
682                                 continue;
683                         obj = &blob->object;
684                         obj->used = 1;
685                         mark_object_reachable(obj);
686                 }
687                 if (active_cache_tree)
688                         fsck_cache_tree(active_cache_tree);
689         }
690
691         check_connectivity();
692         return errors_found;
693 }