Source

git / fsck-objects.c

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
#include <sys/types.h>
#include <dirent.h>

#include "cache.h"
#include "commit.h"
#include "tree.h"
#include "blob.h"
#include "tag.h"
#include "refs.h"
#include "pack.h"
#include "cache-tree.h"
#include "tree-walk.h"

#define REACHABLE 0x0001
#define SEEN      0x0002

static int show_root;
static int show_tags;
static int show_unreachable;
static int check_full;
static int check_strict;
static int keep_cache_objects;
static unsigned char head_sha1[20];

#ifdef NO_D_INO_IN_DIRENT
#define SORT_DIRENT 0
#define DIRENT_SORT_HINT(de) 0
#else
#define SORT_DIRENT 1
#define DIRENT_SORT_HINT(de) ((de)->d_ino)
#endif

static void objreport(struct object *obj, const char *severity,
                      const char *err, va_list params)
{
	fprintf(stderr, "%s in %s %s: ",
	        severity, typename(obj->type), sha1_to_hex(obj->sha1));
	vfprintf(stderr, err, params);
	fputs("\n", stderr);
}

static int objerror(struct object *obj, const char *err, ...)
{
	va_list params;
	va_start(params, err);
	objreport(obj, "error", err, params);
	va_end(params);
	return -1;
}

static int objwarning(struct object *obj, const char *err, ...)
{
	va_list params;
	va_start(params, err);
	objreport(obj, "warning", err, params);
	va_end(params);
	return -1;
}


static void check_connectivity(void)
{
	int i, max;

	/* Look up all the requirements, warn about missing objects.. */
	max = get_max_object_index();
	for (i = 0; i < max; i++) {
		const struct object_refs *refs;
		struct object *obj = get_indexed_object(i);

		if (!obj)
			continue;

		if (!obj->parsed) {
			if (has_sha1_file(obj->sha1))
				; /* it is in pack */
			else
				printf("missing %s %s\n",
				       typename(obj->type), sha1_to_hex(obj->sha1));
			continue;
		}

		refs = lookup_object_refs(obj);
		if (refs) {
			unsigned j;
			for (j = 0; j < refs->count; j++) {
				struct object *ref = refs->ref[j];
				if (ref->parsed ||
				    (has_sha1_file(ref->sha1)))
					continue;
				printf("broken link from %7s %s\n",
				       typename(obj->type), sha1_to_hex(obj->sha1));
				printf("              to %7s %s\n",
				       typename(ref->type), sha1_to_hex(ref->sha1));
			}
		}

		if (show_unreachable && !(obj->flags & REACHABLE)) {
			printf("unreachable %s %s\n",
			       typename(obj->type), sha1_to_hex(obj->sha1));
			continue;
		}

		if (!obj->used) {
			printf("dangling %s %s\n", typename(obj->type),
			       sha1_to_hex(obj->sha1));
		}
	}
}

/*
 * The entries in a tree are ordered in the _path_ order,
 * which means that a directory entry is ordered by adding
 * a slash to the end of it.
 *
 * So a directory called "a" is ordered _after_ a file
 * called "a.c", because "a/" sorts after "a.c".
 */
#define TREE_UNORDERED (-1)
#define TREE_HAS_DUPS  (-2)

static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
{
	int len1 = strlen(name1);
	int len2 = strlen(name2);
	int len = len1 < len2 ? len1 : len2;
	unsigned char c1, c2;
	int cmp;

	cmp = memcmp(name1, name2, len);
	if (cmp < 0)
		return 0;
	if (cmp > 0)
		return TREE_UNORDERED;

	/*
	 * Ok, the first <len> characters are the same.
	 * Now we need to order the next one, but turn
	 * a '\0' into a '/' for a directory entry.
	 */
	c1 = name1[len];
	c2 = name2[len];
	if (!c1 && !c2)
		/*
		 * git-write-tree used to write out a nonsense tree that has
		 * entries with the same name, one blob and one tree.  Make
		 * sure we do not have duplicate entries.
		 */
		return TREE_HAS_DUPS;
	if (!c1 && S_ISDIR(mode1))
		c1 = '/';
	if (!c2 && S_ISDIR(mode2))
		c2 = '/';
	return c1 < c2 ? 0 : TREE_UNORDERED;
}

static int fsck_tree(struct tree *item)
{
	int retval;
	int has_full_path = 0;
	int has_zero_pad = 0;
	int has_bad_modes = 0;
	int has_dup_entries = 0;
	int not_properly_sorted = 0;
	struct tree_desc desc;
	unsigned o_mode;
	const char *o_name;
	const unsigned char *o_sha1;

	desc.buf = item->buffer;
	desc.size = item->size;

	o_mode = 0;
	o_name = NULL;
	o_sha1 = NULL;
	while (desc.size) {
		unsigned mode;
		const char *name;
		const unsigned char *sha1;

		sha1 = tree_entry_extract(&desc, &name, &mode);

		if (strchr(name, '/'))
			has_full_path = 1;
		has_zero_pad |= *(char *)desc.buf == '0';
		update_tree_entry(&desc);

		switch (mode) {
		/*
		 * Standard modes..
		 */
		case S_IFREG | 0755:
		case S_IFREG | 0644:
		case S_IFLNK:
		case S_IFDIR:
			break;
		/*
		 * This is nonstandard, but we had a few of these
		 * early on when we honored the full set of mode
		 * bits..
		 */
		case S_IFREG | 0664:
			if (!check_strict)
				break;
		default:
			has_bad_modes = 1;
		}

		if (o_name) {
			switch (verify_ordered(o_mode, o_name, mode, name)) {
			case TREE_UNORDERED:
				not_properly_sorted = 1;
				break;
			case TREE_HAS_DUPS:
				has_dup_entries = 1;
				break;
			default:
				break;
			}
		}

		o_mode = mode;
		o_name = name;
		o_sha1 = sha1;
	}
	free(item->buffer);
	item->buffer = NULL;

	retval = 0;
	if (has_full_path) {
		objwarning(&item->object, "contains full pathnames");
	}
	if (has_zero_pad) {
		objwarning(&item->object, "contains zero-padded file modes");
	}
	if (has_bad_modes) {
		objwarning(&item->object, "contains bad file modes");
	}
	if (has_dup_entries) {
		retval = objerror(&item->object, "contains duplicate file entries");
	}
	if (not_properly_sorted) {
		retval = objerror(&item->object, "not properly sorted");
	}
	return retval;
}

static int fsck_commit(struct commit *commit)
{
	char *buffer = commit->buffer;
	unsigned char tree_sha1[20], sha1[20];

	if (memcmp(buffer, "tree ", 5))
		return objerror(&commit->object, "invalid format - expected 'tree' line");
	if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
		return objerror(&commit->object, "invalid 'tree' line format - bad sha1");
	buffer += 46;
	while (!memcmp(buffer, "parent ", 7)) {
		if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
			return objerror(&commit->object, "invalid 'parent' line format - bad sha1");
		buffer += 48;
	}
	if (memcmp(buffer, "author ", 7))
		return objerror(&commit->object, "invalid format - expected 'author' line");
	free(commit->buffer);
	commit->buffer = NULL;
	if (!commit->tree)
		return objerror(&commit->object, "could not load commit's tree %s", tree_sha1);
	if (!commit->parents && show_root)
		printf("root %s\n", sha1_to_hex(commit->object.sha1));
	if (!commit->date)
		printf("bad commit date in %s\n", 
		       sha1_to_hex(commit->object.sha1));
	return 0;
}

static int fsck_tag(struct tag *tag)
{
	struct object *tagged = tag->tagged;

	if (!tagged) {
		return objerror(&tag->object, "could not load tagged object");
	}
	if (!show_tags)
		return 0;

	printf("tagged %s %s", typename(tagged->type), sha1_to_hex(tagged->sha1));
	printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
	return 0;
}

static int fsck_sha1(unsigned char *sha1)
{
	struct object *obj = parse_object(sha1);
	if (!obj)
		return error("%s: object not found", sha1_to_hex(sha1));
	if (obj->flags & SEEN)
		return 0;
	obj->flags |= SEEN;
	if (obj->type == OBJ_BLOB)
		return 0;
	if (obj->type == OBJ_TREE)
		return fsck_tree((struct tree *) obj);
	if (obj->type == OBJ_COMMIT)
		return fsck_commit((struct commit *) obj);
	if (obj->type == OBJ_TAG)
		return fsck_tag((struct tag *) obj);
	/* By now, parse_object() would've returned NULL instead. */
	return objerror(obj, "unknown type '%d' (internal fsck error)", obj->type);
}

/*
 * This is the sorting chunk size: make it reasonably
 * big so that we can sort well..
 */
#define MAX_SHA1_ENTRIES (1024)

struct sha1_entry {
	unsigned long ino;
	unsigned char sha1[20];
};

static struct {
	unsigned long nr;
	struct sha1_entry *entry[MAX_SHA1_ENTRIES];
} sha1_list;

static int ino_compare(const void *_a, const void *_b)
{
	const struct sha1_entry *a = _a, *b = _b;
	unsigned long ino1 = a->ino, ino2 = b->ino;
	return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
}

static void fsck_sha1_list(void)
{
	int i, nr = sha1_list.nr;

	if (SORT_DIRENT)
		qsort(sha1_list.entry, nr,
		      sizeof(struct sha1_entry *), ino_compare);
	for (i = 0; i < nr; i++) {
		struct sha1_entry *entry = sha1_list.entry[i];
		unsigned char *sha1 = entry->sha1;

		sha1_list.entry[i] = NULL;
		fsck_sha1(sha1);
		free(entry);
	}
	sha1_list.nr = 0;
}

static void add_sha1_list(unsigned char *sha1, unsigned long ino)
{
	struct sha1_entry *entry = xmalloc(sizeof(*entry));
	int nr;

	entry->ino = ino;
	hashcpy(entry->sha1, sha1);
	nr = sha1_list.nr;
	if (nr == MAX_SHA1_ENTRIES) {
		fsck_sha1_list();
		nr = 0;
	}
	sha1_list.entry[nr] = entry;
	sha1_list.nr = ++nr;
}

static void fsck_dir(int i, char *path)
{
	DIR *dir = opendir(path);
	struct dirent *de;

	if (!dir)
		return;

	while ((de = readdir(dir)) != NULL) {
		char name[100];
		unsigned char sha1[20];
		int len = strlen(de->d_name);

		switch (len) {
		case 2:
			if (de->d_name[1] != '.')
				break;
		case 1:
			if (de->d_name[0] != '.')
				break;
			continue;
		case 38:
			sprintf(name, "%02x", i);
			memcpy(name+2, de->d_name, len+1);
			if (get_sha1_hex(name, sha1) < 0)
				break;
			add_sha1_list(sha1, DIRENT_SORT_HINT(de));
			continue;
		}
		fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
	}
	closedir(dir);
}

static int default_refs;

static int fsck_handle_ref(const char *refname, const unsigned char *sha1)
{
	struct object *obj;

	obj = lookup_object(sha1);
	if (!obj) {
		if (has_sha1_file(sha1)) {
			default_refs++;
			return 0; /* it is in a pack */
		}
		error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
		/* We'll continue with the rest despite the error.. */
		return 0;
	}
	default_refs++;
	obj->used = 1;
	mark_reachable(obj, REACHABLE);
	return 0;
}

static void get_default_heads(void)
{
	for_each_ref(fsck_handle_ref);

	/*
	 * Not having any default heads isn't really fatal, but
	 * it does mean that "--unreachable" no longer makes any
	 * sense (since in this case everything will obviously
	 * be unreachable by definition.
	 *
	 * Showing dangling objects is valid, though (as those
	 * dangling objects are likely lost heads).
	 *
	 * So we just print a warning about it, and clear the
	 * "show_unreachable" flag.
	 */
	if (!default_refs) {
		error("No default references");
		show_unreachable = 0;
	}
}

static void fsck_object_dir(const char *path)
{
	int i;
	for (i = 0; i < 256; i++) {
		static char dir[4096];
		sprintf(dir, "%s/%02x", path, i);
		fsck_dir(i, dir);
	}
	fsck_sha1_list();
}

static int fsck_head_link(void)
{
	unsigned char sha1[20];
	const char *git_HEAD = xstrdup(git_path("HEAD"));
	const char *git_refs_heads_master = resolve_ref(git_HEAD, sha1, 1);
	int pfxlen = strlen(git_HEAD) - 4; /* strip .../.git/ part */

	if (!git_refs_heads_master)
		return error("HEAD is not a symbolic ref");
	if (strncmp(git_refs_heads_master + pfxlen, "refs/heads/", 11))
		return error("HEAD points to something strange (%s)",
			     git_refs_heads_master + pfxlen);
	if (is_null_sha1(sha1))
		return error("HEAD: not a valid git pointer");
	return 0;
}

static int fsck_cache_tree(struct cache_tree *it)
{
	int i;
	int err = 0;

	if (0 <= it->entry_count) {
		struct object *obj = parse_object(it->sha1);
		if (!obj) {
			error("%s: invalid sha1 pointer in cache-tree",
			      sha1_to_hex(it->sha1));
			return 1;
		}
		mark_reachable(obj, REACHABLE);
		obj->used = 1;
		if (obj->type != OBJ_TREE)
			err |= objerror(obj, "non-tree in cache-tree");
	}
	for (i = 0; i < it->subtree_nr; i++)
		err |= fsck_cache_tree(it->down[i]->cache_tree);
	return err;
}

int main(int argc, char **argv)
{
	int i, heads;

	track_object_refs = 1;
	setup_git_directory();

	for (i = 1; i < argc; i++) {
		const char *arg = argv[i];

		if (!strcmp(arg, "--unreachable")) {
			show_unreachable = 1;
			continue;
		}
		if (!strcmp(arg, "--tags")) {
			show_tags = 1;
			continue;
		}
		if (!strcmp(arg, "--root")) {
			show_root = 1;
			continue;
		}
		if (!strcmp(arg, "--cache")) {
			keep_cache_objects = 1;
			continue;
		}
		if (!strcmp(arg, "--full")) {
			check_full = 1;
			continue;
		}
		if (!strcmp(arg, "--strict")) {
			check_strict = 1;
			continue;
		}
		if (*arg == '-')
			usage("git-fsck-objects [--tags] [--root] [[--unreachable] [--cache] [--full] [--strict] <head-sha1>*]");
	}

	fsck_head_link();
	fsck_object_dir(get_object_directory());
	if (check_full) {
		struct alternate_object_database *alt;
		struct packed_git *p;
		prepare_alt_odb();
		for (alt = alt_odb_list; alt; alt = alt->next) {
			char namebuf[PATH_MAX];
			int namelen = alt->name - alt->base;
			memcpy(namebuf, alt->base, namelen);
			namebuf[namelen - 1] = 0;
			fsck_object_dir(namebuf);
		}
		prepare_packed_git();
		for (p = packed_git; p; p = p->next)
			/* verify gives error messages itself */
			verify_pack(p, 0);

		for (p = packed_git; p; p = p->next) {
			int num = num_packed_objects(p);
			for (i = 0; i < num; i++) {
				unsigned char sha1[20];
				nth_packed_object_sha1(p, i, sha1);
				fsck_sha1(sha1);
			}
		}
	}

	heads = 0;
	for (i = 1; i < argc; i++) {
		const char *arg = argv[i]; 

		if (*arg == '-')
			continue;

		if (!get_sha1(arg, head_sha1)) {
			struct object *obj = lookup_object(head_sha1);

			/* Error is printed by lookup_object(). */
			if (!obj)
				continue;

			obj->used = 1;
			mark_reachable(obj, REACHABLE);
			heads++;
			continue;
		}
		error("invalid parameter: expected sha1, got '%s'", arg);
	}

	/*
	 * If we've not been given any explicit head information, do the
	 * default ones from .git/refs. We also consider the index file
	 * in this case (ie this implies --cache).
	 */
	if (!heads) {
		get_default_heads();
		keep_cache_objects = 1;
	}

	if (keep_cache_objects) {
		int i;
		read_cache();
		for (i = 0; i < active_nr; i++) {
			struct blob *blob = lookup_blob(active_cache[i]->sha1);
			struct object *obj;
			if (!blob)
				continue;
			obj = &blob->object;
			obj->used = 1;
			mark_reachable(obj, REACHABLE);
		}
		if (active_cache_tree)
			fsck_cache_tree(active_cache_tree);
	}

	check_connectivity();
	return 0;
}