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