aboutsummaryrefslogtreecommitdiff
path: root/fsck-cache.c
blob: 48be6553a3b1d9b7e4b9a3382646bf753e15a4f3 (plain)
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
#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"

#define REACHABLE 0x0001

static int show_root = 0;
static int show_tags = 0;
static int show_unreachable = 0;
static int standalone = 0;
static int check_full = 0;
static int keep_cache_objects = 0; 
static unsigned char head_sha1[20];

static void check_connectivity(void)
{
	int i;

	/* Look up all the requirements, warn about missing objects.. */
	for (i = 0; i < nr_objs; i++) {
		struct object *obj = objs[i];
		struct object_list *refs;

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

		for (refs = obj->refs; refs; refs = refs->next) {
			if (refs->item->parsed ||
			    (!standalone && has_sha1_file(refs->item->sha1)))
				continue;
			printf("broken link from %7s %s\n",
			       obj->type, sha1_to_hex(obj->sha1));
			printf("              to %7s %s\n",
			       refs->item->type, sha1_to_hex(refs->item->sha1));
		}

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

		if (!obj->used) {
			printf("dangling %s %s\n", 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(struct tree_entry_list *a, struct tree_entry_list *b)
{
	int len1 = strlen(a->name);
	int len2 = strlen(b->name);
	int len = len1 < len2 ? len1 : len2;
	unsigned char c1, c2;
	int cmp;

	cmp = memcmp(a->name, b->name, 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 = a->name[len];
	c2 = b->name[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 && a->directory)
		c1 = '/';
	if (!c2 && b->directory)
		c2 = '/';
	return c1 < c2 ? 0 : TREE_UNORDERED;
}

static int fsck_tree(struct tree *item)
{
	int has_full_path = 0;
	struct tree_entry_list *entry, *last;

	last = NULL;
	for (entry = item->entries; entry; entry = entry->next) {
		if (strchr(entry->name, '/'))
			has_full_path = 1;

		switch (entry->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:
			break;
		default:
			printf("tree %s has entry %o %s\n",
				sha1_to_hex(item->object.sha1),
				entry->mode, entry->name);
		}

		if (last) {
			switch (verify_ordered(last, entry)) {
			case TREE_UNORDERED:
				fprintf(stderr, "tree %s not ordered\n",
					sha1_to_hex(item->object.sha1));
				return -1;
			case TREE_HAS_DUPS:
				fprintf(stderr, "tree %s has duplicate entries for '%s'\n",
					sha1_to_hex(item->object.sha1),
					entry->name);
				return -1;
			default:
				break;
			}
		}

		last = entry;
	}

	if (has_full_path) {
		fprintf(stderr, "warning: git-fsck-cache: tree %s "
			"has full pathnames in it\n", 
			sha1_to_hex(item->object.sha1));
	}

	return 0;
}

static int fsck_commit(struct commit *commit)
{
	free(commit->buffer);
	commit->buffer = NULL;
	if (!commit->tree)
		return -1;
	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) {
		printf("bad object in tag %s\n", sha1_to_hex(tag->object.sha1));
		return -1;
	}
	if (!show_tags)
		return 0;

	printf("tagged %s %s", 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 -1;
	if (obj->type == blob_type)
		return 0;
	if (obj->type == tree_type)
		return fsck_tree((struct tree *) obj);
	if (obj->type == commit_type)
		return fsck_commit((struct commit *) obj);
	if (obj->type == tag_type)
		return fsck_tag((struct tag *) obj);
	return -1;
}

/*
 * 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;

	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;
		if (fsck_sha1(sha1) < 0)
			fprintf(stderr, "bad sha1 entry '%s'\n", sha1_to_hex(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;
	memcpy(entry->sha1, sha1, 20);
	nr = sha1_list.nr;
	if (nr == MAX_SHA1_ENTRIES) {
		fsck_sha1_list();
		nr = 0;
	}
	sha1_list.entry[nr] = entry;
	sha1_list.nr = ++nr;
}

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

	if (!dir) {
		return error("missing sha1 directory '%s'", path);
	}

	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, de->d_ino);
			continue;
		}
		fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
	}
	closedir(dir);
	return 0;
}

static int default_refs = 0;

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

	obj = lookup_object(sha1);
	if (!obj) {
		if (!standalone && 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);
	if (!default_refs)
		die("No default references");
}

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)
{
	int fd, count;
	char hex[40];
	unsigned char sha1[20];
	static char path[PATH_MAX], link[PATH_MAX];
	const char *git_dir = gitenv(GIT_DIR_ENVIRONMENT) ? : DEFAULT_GIT_DIR_ENVIRONMENT;

	snprintf(path, sizeof(path), "%s/HEAD", git_dir);
	if (readlink(path, link, sizeof(link)) < 0)
		return error("HEAD is not a symlink");
	if (strncmp("refs/heads/", link, 11))
		return error("HEAD points to something strange (%s)", link);
	fd = open(path, O_RDONLY);
	if (fd < 0)
		return error("HEAD: %s", strerror(errno));
	count = read(fd, hex, sizeof(hex));
	close(fd);
	if (count < 0)
		return error("HEAD: %s", strerror(errno));
	if (count < 40 || get_sha1_hex(hex, sha1))
		return error("HEAD: not a valid git pointer");
	return 0;
}

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

	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, "--standalone")) {
			standalone = 1;
			continue;
		}
		if (!strcmp(arg, "--full")) {
			check_full = 1;
			continue;
		}
		if (*arg == '-')
			usage("git-fsck-cache [--tags] [[--unreachable] [--cache] [--standalone | --full] <head-sha1>*]");
	}

	if (standalone && check_full)
		die("Only one of --standalone or --full can be used.");
	if (standalone)
		unsetenv("GIT_ALTERNATE_OBJECT_DIRECTORIES");

	fsck_head_link();
	fsck_object_dir(get_object_directory());
	if (check_full) {
		int j;
		struct packed_git *p;
		prepare_alt_odb();
		for (j = 0; alt_odb[j].base; j++) {
			alt_odb[j].name[-1] = 0; /* was slash */
			fsck_object_dir(alt_odb[j].base);
			alt_odb[j].name[-1] = '/';
		}
		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);
				if (fsck_sha1(sha1) < 0)
					fprintf(stderr, "bad sha1 entry '%s'\n", sha1_to_hex(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("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);
		}
	}

	check_connectivity();
	return 0;
}