1 /*
2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/stat.h>
18 #include <sys/limits.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 
22 #include <stddef.h>
23 #include <string.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <fcntl.h>
27 #include <errno.h>
28 #include <unistd.h>
29 #include <sha1.h>
30 #include <zlib.h>
31 #include <fnmatch.h>
32 #include <libgen.h>
33 
34 #include "got_error.h"
35 #include "got_repository.h"
36 #include "got_reference.h"
37 #include "got_object.h"
38 #include "got_worktree.h"
39 #include "got_opentemp.h"
40 
41 #include "got_lib_worktree.h"
42 #include "got_lib_path.h"
43 #include "got_lib_sha1.h"
44 #include "got_lib_fileindex.h"
45 #include "got_lib_inflate.h"
46 #include "got_lib_delta.h"
47 #include "got_lib_object.h"
48 
49 #ifndef MIN
50 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
51 #endif
52 
53 static const struct got_error *
54 create_meta_file(const char *path_got, const char *name, const char *content)
55 {
56 	const struct got_error *err = NULL;
57 	char *path;
58 	int fd = -1;
59 
60 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
61 		err = got_error_from_errno();
62 		path = NULL;
63 		goto done;
64 	}
65 
66 	fd = open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
67 	    GOT_DEFAULT_FILE_MODE);
68 	if (fd == -1) {
69 		err = got_error_from_errno();
70 		goto done;
71 	}
72 
73 	if (content) {
74 		int len = dprintf(fd, "%s\n", content);
75 		if (len != strlen(content) + 1) {
76 			err = got_error_from_errno();
77 			goto done;
78 		}
79 	}
80 
81 done:
82 	if (fd != -1 && close(fd) == -1 && err == NULL)
83 		err = got_error_from_errno();
84 	free(path);
85 	return err;
86 }
87 
88 static const struct got_error *
89 update_meta_file(const char *path_got, const char *name, const char *content)
90 {
91 	const struct got_error *err = NULL;
92 	FILE *tmpfile = NULL;
93 	char *tmppath = NULL;
94 	char *path = NULL;
95 
96 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
97 		err = got_error_from_errno();
98 		path = NULL;
99 		goto done;
100 	}
101 
102 	err = got_opentemp_named(&tmppath, &tmpfile, path);
103 	if (err)
104 		goto done;
105 
106 	if (content) {
107 		int len = fprintf(tmpfile, "%s\n", content);
108 		if (len != strlen(content) + 1) {
109 			err = got_error_from_errno();
110 			goto done;
111 		}
112 	}
113 
114 	if (rename(tmppath, path) != 0) {
115 		err = got_error_from_errno();
116 		goto done;
117 	}
118 
119 done:
120 	free(tmppath);
121 	fclose(tmpfile);
122 	return err;
123 }
124 
125 static const struct got_error *
126 read_meta_file(char **content, const char *path_got, const char *name)
127 {
128 	const struct got_error *err = NULL;
129 	char *path;
130 	int fd = -1;
131 	ssize_t n;
132 	struct stat sb;
133 
134 	*content = NULL;
135 
136 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
137 		err = got_error_from_errno();
138 		path = NULL;
139 		goto done;
140 	}
141 
142 	fd = open(path, O_RDONLY | O_NOFOLLOW);
143 	if (fd == -1) {
144 		err = got_error_from_errno();
145 		goto done;
146 	}
147 	if (flock(fd, LOCK_SH | LOCK_NB) == -1) {
148 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
149 		    : got_error_from_errno());
150 		goto done;
151 	}
152 
153 	stat(path, &sb);
154 	*content = calloc(1, sb.st_size);
155 	if (*content == NULL) {
156 		err = got_error_from_errno();
157 		goto done;
158 	}
159 
160 	n = read(fd, *content, sb.st_size);
161 	if (n != sb.st_size) {
162 		err = (n == -1 ? got_error_from_errno() :
163 		    got_error(GOT_ERR_WORKTREE_META));
164 		goto done;
165 	}
166 	if ((*content)[sb.st_size - 1] != '\n') {
167 		err = got_error(GOT_ERR_WORKTREE_META);
168 		goto done;
169 	}
170 	(*content)[sb.st_size - 1] = '\0';
171 
172 done:
173 	if (fd != -1 && close(fd) == -1 && err == NULL)
174 		err = got_error_from_errno();
175 	free(path);
176 	if (err) {
177 		free(*content);
178 		*content = NULL;
179 	}
180 	return err;
181 }
182 
183 const struct got_error *
184 got_worktree_init(const char *path, struct got_reference *head_ref,
185     const char *prefix, struct got_repository *repo)
186 {
187 	const struct got_error *err = NULL;
188 	struct got_object_id *commit_id = NULL;
189 	int obj_type;
190 	char *path_got = NULL;
191 	char *refstr = NULL;
192 	char *formatstr = NULL;
193 	char *absprefix = NULL;
194 	char *basestr = NULL;
195 
196 	err = got_ref_resolve(&commit_id, repo, head_ref);
197 	if (err)
198 		return err;
199 	err = got_object_get_type(&obj_type, repo, commit_id);
200 	if (err)
201 		return err;
202 	if (obj_type != GOT_OBJ_TYPE_COMMIT)
203 		return got_error(GOT_ERR_OBJ_TYPE);
204 
205 	if (!got_path_is_absolute(prefix)) {
206 		if (asprintf(&absprefix, "/%s", prefix) == -1)
207 			return got_error_from_errno();
208 	}
209 
210 	/* Create top-level directory (may already exist). */
211 	if (mkdir(path, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
212 		err = got_error_from_errno();
213 		goto done;
214 	}
215 
216 	/* Create .got directory (may already exist). */
217 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
218 		err = got_error_from_errno();
219 		goto done;
220 	}
221 	if (mkdir(path_got, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
222 		err = got_error_from_errno();
223 		goto done;
224 	}
225 
226 	/* Create an empty lock file. */
227 	err = create_meta_file(path_got, GOT_WORKTREE_LOCK, NULL);
228 	if (err)
229 		goto done;
230 
231 	/* Create an empty file index. */
232 	err = create_meta_file(path_got, GOT_WORKTREE_FILE_INDEX, NULL);
233 	if (err)
234 		goto done;
235 
236 	/* Write the HEAD reference. */
237 	refstr = got_ref_to_str(head_ref);
238 	if (refstr == NULL) {
239 		err = got_error_from_errno();
240 		goto done;
241 	}
242 	err = create_meta_file(path_got, GOT_WORKTREE_HEAD_REF, refstr);
243 	if (err)
244 		goto done;
245 
246 	/* Record our base commit. */
247 	err = got_object_id_str(&basestr, commit_id);
248 	if (err)
249 		goto done;
250 	err = create_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, basestr);
251 	if (err)
252 		goto done;
253 
254 	/* Store path to repository. */
255 	err = create_meta_file(path_got, GOT_WORKTREE_REPOSITORY,
256 	    got_repo_get_path(repo));
257 	if (err)
258 		goto done;
259 
260 	/* Store in-repository path prefix. */
261 	err = create_meta_file(path_got, GOT_WORKTREE_PATH_PREFIX,
262 	    absprefix ? absprefix : prefix);
263 	if (err)
264 		goto done;
265 
266 	/* Stamp work tree with format file. */
267 	if (asprintf(&formatstr, "%d", GOT_WORKTREE_FORMAT_VERSION) == -1) {
268 		err = got_error_from_errno();
269 		goto done;
270 	}
271 	err = create_meta_file(path_got, GOT_WORKTREE_FORMAT, formatstr);
272 	if (err)
273 		goto done;
274 
275 done:
276 	free(commit_id);
277 	free(path_got);
278 	free(formatstr);
279 	free(refstr);
280 	free(absprefix);
281 	free(basestr);
282 	return err;
283 }
284 
285 const struct got_error *
286 got_worktree_open(struct got_worktree **worktree, const char *path)
287 {
288 	const struct got_error *err = NULL;
289 	char *path_got;
290 	char *formatstr = NULL;
291 	char *path_lock = NULL;
292 	char *base_commit_id_str = NULL;
293 	char *head_ref_str = NULL;
294 	int version, fd = -1;
295 	const char *errstr;
296 	struct got_repository *repo = NULL;
297 
298 	*worktree = NULL;
299 
300 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
301 		err = got_error_from_errno();
302 		path_got = NULL;
303 		goto done;
304 	}
305 
306 	if (asprintf(&path_lock, "%s/%s", path_got, GOT_WORKTREE_LOCK) == -1) {
307 		err = got_error_from_errno();
308 		path_lock = NULL;
309 		goto done;
310 	}
311 
312 	fd = open(path_lock, O_RDWR | O_EXLOCK | O_NONBLOCK);
313 	if (fd == -1) {
314 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
315 		    : got_error_from_errno());
316 		goto done;
317 	}
318 
319 	err = read_meta_file(&formatstr, path_got, GOT_WORKTREE_FORMAT);
320 	if (err)
321 		goto done;
322 
323 	version = strtonum(formatstr, 1, INT_MAX, &errstr);
324 	if (errstr) {
325 		err = got_error(GOT_ERR_WORKTREE_META);
326 		goto done;
327 	}
328 	if (version != GOT_WORKTREE_FORMAT_VERSION) {
329 		err = got_error(GOT_ERR_WORKTREE_VERS);
330 		goto done;
331 	}
332 
333 	*worktree = calloc(1, sizeof(**worktree));
334 	if (*worktree == NULL) {
335 		err = got_error_from_errno();
336 		goto done;
337 	}
338 	(*worktree)->lockfd = -1;
339 
340 	(*worktree)->root_path = strdup(path);
341 	if ((*worktree)->root_path == NULL) {
342 		err = got_error_from_errno();
343 		goto done;
344 	}
345 	err = read_meta_file(&(*worktree)->repo_path, path_got,
346 	    GOT_WORKTREE_REPOSITORY);
347 	if (err)
348 		goto done;
349 
350 	err = read_meta_file(&(*worktree)->path_prefix, path_got,
351 	    GOT_WORKTREE_PATH_PREFIX);
352 	if (err)
353 		goto done;
354 
355 	err = read_meta_file(&base_commit_id_str, path_got,
356 	    GOT_WORKTREE_BASE_COMMIT);
357 	if (err)
358 		goto done;
359 
360 	err = got_repo_open(&repo, (*worktree)->repo_path);
361 	if (err)
362 		goto done;
363 
364 	err = got_object_resolve_id_str(&(*worktree)->base_commit_id, repo,
365 	    base_commit_id_str);
366 	if (err)
367 		goto done;
368 
369 	err = read_meta_file(&head_ref_str, path_got, GOT_WORKTREE_HEAD_REF);
370 	if (err)
371 		goto done;
372 
373 	err = got_ref_open(&(*worktree)->head_ref, repo, head_ref_str);
374 done:
375 	if (repo)
376 		got_repo_close(repo);
377 	free(path_got);
378 	free(path_lock);
379 	free(head_ref_str);
380 	free(base_commit_id_str);
381 	if (err) {
382 		if (fd != -1)
383 			close(fd);
384 		if (*worktree != NULL)
385 			got_worktree_close(*worktree);
386 		*worktree = NULL;
387 	} else
388 		(*worktree)->lockfd = fd;
389 
390 	return err;
391 }
392 
393 void
394 got_worktree_close(struct got_worktree *worktree)
395 {
396 	free(worktree->root_path);
397 	free(worktree->repo_path);
398 	free(worktree->path_prefix);
399 	free(worktree->base_commit_id);
400 	if (worktree->head_ref)
401 		got_ref_close(worktree->head_ref);
402 	if (worktree->lockfd != -1)
403 		close(worktree->lockfd);
404 	free(worktree);
405 }
406 
407 const char *
408 got_worktree_get_repo_path(struct got_worktree *worktree)
409 {
410 	return worktree->repo_path;
411 }
412 
413 const char *
414 got_worktree_get_path_prefix(struct got_worktree *worktree)
415 {
416 	return worktree->path_prefix;
417 }
418 
419 const struct got_error *
420 got_worktree_match_path_prefix(int *match, struct got_worktree *worktree,
421     const char *path_prefix)
422 {
423 	char *absprefix = NULL;
424 
425 	if (!got_path_is_absolute(path_prefix)) {
426 		if (asprintf(&absprefix, "/%s", path_prefix) == -1)
427 			return got_error_from_errno();
428 	}
429 	*match = (strcmp(absprefix ? absprefix : path_prefix,
430 	    worktree->path_prefix) == 0);
431 	free(absprefix);
432 	return NULL;
433 }
434 
435 char *
436 got_worktree_get_head_ref_name(struct got_worktree *worktree)
437 {
438 	return got_ref_to_str(worktree->head_ref);
439 }
440 
441 struct got_reference *
442 got_worktree_get_head_ref(struct got_worktree *worktree)
443 {
444 	return got_ref_dup(worktree->head_ref);
445 }
446 
447 const struct got_object_id *
448 got_worktree_get_base_commit_id(struct got_worktree *worktree)
449 {
450 	return worktree->base_commit_id;
451 }
452 
453 const struct got_error *
454 got_worktree_set_base_commit_id(struct got_worktree *worktree,
455     struct got_repository *repo, struct got_object_id *commit_id)
456 {
457 	const struct got_error *err;
458 	struct got_object *obj = NULL;
459 	char *id_str = NULL;
460 	char *path_got = NULL;
461 
462 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
463 	    GOT_WORKTREE_GOT_DIR) == -1) {
464 		err = got_error_from_errno();
465 		path_got = NULL;
466 		goto done;
467 	}
468 
469 	err = got_object_open(&obj, repo, commit_id);
470 	if (err)
471 		return err;
472 
473 	if (obj->type != GOT_OBJ_TYPE_COMMIT) {
474 		err = got_error(GOT_ERR_OBJ_TYPE);
475 		goto done;
476 	}
477 
478 	/* Record our base commit. */
479 	err = got_object_id_str(&id_str, commit_id);
480 	if (err)
481 		goto done;
482 	err = update_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, id_str);
483 	if (err)
484 		goto done;
485 
486 	free(worktree->base_commit_id);
487 	worktree->base_commit_id = got_object_id_dup(commit_id);
488 	if (worktree->base_commit_id == NULL) {
489 		err = got_error_from_errno();
490 		goto done;
491 	}
492 done:
493 	if (obj)
494 		got_object_close(obj);
495 	free(id_str);
496 	free(path_got);
497 	return err;
498 }
499 
500 static const struct got_error *
501 lock_worktree(struct got_worktree *worktree, int operation)
502 {
503 	if (flock(worktree->lockfd, operation | LOCK_NB) == -1)
504 		return (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
505 		    : got_error_from_errno());
506 	return NULL;
507 }
508 
509 static const struct got_error *
510 install_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
511    struct got_fileindex_entry *entry, const char *path,
512    struct got_blob_object *blob,
513    struct got_repository *repo, got_worktree_checkout_cb progress_cb,
514    void *progress_arg)
515 {
516 	const struct got_error *err = NULL;
517 	char *ondisk_path;
518 	int fd = -1;
519 	size_t len, hdrlen;
520 	int update = 0;
521 	char *tmppath = NULL;
522 
523 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
524 		return got_error_from_errno();
525 
526 	fd = open(ondisk_path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
527 	    GOT_DEFAULT_FILE_MODE);
528 	if (fd == -1) {
529 		err = got_error_from_errno();
530 		if (errno == EEXIST) {
531 			struct stat sb;
532 			if (lstat(ondisk_path, &sb) == -1) {
533 				err = got_error_from_errno();
534 				goto done;
535 			} else if (!S_ISREG(sb.st_mode)) {
536 				/* TODO file is obstructed; do something */
537 				err = got_error(GOT_ERR_FILE_OBSTRUCTED);
538 				goto done;
539 			} else {
540 				err = got_opentemp_named_fd(&tmppath, &fd,
541 				    ondisk_path);
542 				if (err)
543 					goto done;
544 				update = 1;
545 			}
546 		} else
547 			return err;
548 	}
549 
550 	(*progress_cb)(progress_arg,
551 	    update ? GOT_STATUS_UPDATE : GOT_STATUS_ADD, path);
552 
553 	hdrlen = got_object_blob_get_hdrlen(blob);
554 	do {
555 		const uint8_t *buf = got_object_blob_get_read_buf(blob);
556 		err = got_object_blob_read_block(&len, blob);
557 		if (err)
558 			break;
559 		if (len > 0) {
560 			/* Skip blob object header first time around. */
561 			ssize_t outlen = write(fd, buf + hdrlen, len - hdrlen);
562 			if (outlen == -1) {
563 				err = got_error_from_errno();
564 				goto done;
565 			} else if (outlen != len - hdrlen) {
566 				err = got_error(GOT_ERR_IO);
567 				goto done;
568 			}
569 			hdrlen = 0;
570 		}
571 	} while (len != 0);
572 
573 	fsync(fd);
574 
575 	if (update) {
576 		if (rename(tmppath, ondisk_path) != 0) {
577 			err = got_error_from_errno();
578 			goto done;
579 		}
580 	}
581 
582 	if (entry)
583 		err = got_fileindex_entry_update(entry, ondisk_path,
584 		    blob->id.sha1, worktree->base_commit_id->sha1);
585 	else {
586 		err = got_fileindex_entry_alloc(&entry, ondisk_path,
587 		    path, blob->id.sha1, worktree->base_commit_id->sha1);
588 		if (err)
589 			goto done;
590 		err = got_fileindex_entry_add(fileindex, entry);
591 	}
592 	if (err)
593 		goto done;
594 done:
595 	if (fd != -1)
596 		close(fd);
597 	free(ondisk_path);
598 	free(tmppath);
599 	return err;
600 }
601 
602 static const struct got_error *
603 add_dir_on_disk(struct got_worktree *worktree, const char *path)
604 {
605 	const struct got_error *err = NULL;
606 	char *abspath;
607 
608 	if (asprintf(&abspath, "%s/%s", worktree->root_path, path) == -1)
609 		return got_error_from_errno();
610 
611 	/* XXX queue work rather than editing disk directly? */
612 	if (mkdir(abspath, GOT_DEFAULT_DIR_MODE) == -1) {
613 		struct stat sb;
614 
615 		if (errno != EEXIST) {
616 			err = got_error_from_errno();
617 			goto done;
618 		}
619 
620 		if (lstat(abspath, &sb) == -1) {
621 			err = got_error_from_errno();
622 			goto done;
623 		}
624 
625 		if (!S_ISDIR(sb.st_mode)) {
626 			/* TODO directory is obstructed; do something */
627 			return got_error(GOT_ERR_FILE_OBSTRUCTED);
628 		}
629 	}
630 
631 done:
632 	free(abspath);
633 	return err;
634 }
635 
636 static const struct got_error *
637 update_blob(struct got_worktree *worktree,
638     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
639     struct got_tree_entry *te, const char *path,
640     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
641     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
642 {
643 	const struct got_error *err = NULL;
644 	struct got_blob_object *blob = NULL;
645 
646 	if (ie) {
647 		if (memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
648 		    SHA1_DIGEST_LENGTH) == 0) {
649 			(*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
650 			    path);
651 			return NULL;
652 		}
653 		if (memcmp(ie->blob_sha1,
654 		    te->id->sha1, SHA1_DIGEST_LENGTH) == 0)
655 			return NULL;
656 	}
657 
658 	err = got_object_open_as_blob(&blob, repo, te->id, 8192);
659 	if (err)
660 		return err;
661 
662 	err = install_blob(worktree, fileindex, ie, path, blob, repo,
663 	    progress_cb, progress_arg);
664 	got_object_blob_close(blob);
665 	return err;
666 }
667 
668 static const struct got_error *
669 remove_ondisk_file(const char *root_path, const char *path)
670 {
671 	const struct got_error *err = NULL;
672 	char *ondisk_path = NULL;
673 
674 	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
675 		return got_error_from_errno();
676 
677 	if (unlink(ondisk_path) == -1)
678 		err = got_error_from_errno();
679 	else {
680 		char *parent = dirname(ondisk_path);
681 		while (parent && strcmp(parent, root_path) != 0) {
682 			if (rmdir(parent) == -1) {
683 				if (errno != ENOTEMPTY)
684 					err = got_error_from_errno();
685 				break;
686 			}
687 			parent = dirname(parent);
688 		}
689 	}
690 	free(ondisk_path);
691 	return err;
692 }
693 
694 struct diff_cb_arg {
695     struct got_fileindex *fileindex;
696     struct got_worktree *worktree;
697     struct got_repository *repo;
698     got_worktree_checkout_cb progress_cb;
699     void *progress_arg;
700     got_worktree_cancel_cb cancel_cb;
701     void *cancel_arg;
702 };
703 
704 static const struct got_error *
705 diff_old_new(void *arg, struct got_fileindex_entry *ie,
706     struct got_tree_entry *te, const char *parent_path)
707 {
708 	struct diff_cb_arg *a = arg;
709 
710 	return update_blob(a->worktree, a->fileindex, ie, te,
711 	    ie->path, a->repo, a->progress_cb, a->progress_arg,
712 	    a->cancel_cb, a->cancel_arg);
713 }
714 
715 static const struct got_error *
716 diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
717 {
718 	const struct got_error *err;
719 	struct diff_cb_arg *a = arg;
720 
721 	(*a->progress_cb)(a->progress_arg, GOT_STATUS_DELETE, ie->path);
722 
723 	err = remove_ondisk_file(a->worktree->root_path, ie->path);
724 	if (err)
725 		return err;
726 	got_fileindex_entry_remove(a->fileindex, ie);
727 	return NULL;
728 }
729 
730 static const struct got_error *
731 diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
732 {
733 	struct diff_cb_arg *a = arg;
734 	const struct got_error *err;
735 	char *path;
736 
737 	if (asprintf(&path, "%s%s%s", parent_path,
738 	    parent_path[0] ? "/" : "", te->name)
739 	    == -1)
740 		return got_error_from_errno();
741 
742 	if (S_ISDIR(te->mode))
743 		err = add_dir_on_disk(a->worktree, path);
744 	else
745 		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
746 		    a->repo, a->progress_cb, a->progress_arg,
747 		    a->cancel_cb, a->cancel_arg);
748 
749 	free(path);
750 	return err;
751 }
752 
753 const struct got_error *
754 got_worktree_checkout_files(struct got_worktree *worktree,
755     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
756     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
757 {
758 	const struct got_error *err = NULL, *unlockerr, *checkout_err = NULL;
759 	struct got_commit_object *commit = NULL;
760 	struct got_object_id *tree_id = NULL;
761 	struct got_tree_object *tree = NULL;
762 	char *fileindex_path = NULL, *new_fileindex_path = NULL;
763 	struct got_fileindex *fileindex = NULL;
764 	FILE *index = NULL, *new_index = NULL;
765 	struct got_fileindex_diff_cb diff_cb;
766 	struct diff_cb_arg arg;
767 
768 	err = lock_worktree(worktree, LOCK_EX);
769 	if (err)
770 		return err;
771 
772 	fileindex = got_fileindex_alloc();
773 	if (fileindex == NULL) {
774 		err = got_error_from_errno();
775 		goto done;
776 	}
777 
778 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
779 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
780 		err = got_error_from_errno();
781 		fileindex_path = NULL;
782 		goto done;
783 	}
784 
785 	/*
786 	 * Read the file index.
787 	 * Checking out files is supposed to be an idempotent operation.
788 	 * If the on-disk file index is incomplete we will try to complete it.
789 	 */
790 	index = fopen(fileindex_path, "rb");
791 	if (index == NULL) {
792 		err = got_error_from_errno();
793 		goto done;
794 	}
795 	err = got_fileindex_read(fileindex, index);
796 	fclose(index);
797 	if (err)
798 		goto done;
799 
800 	err = got_opentemp_named(&new_fileindex_path, &new_index,
801 	    fileindex_path);
802 	if (err)
803 		goto done;
804 
805 	err = got_object_open_as_commit(&commit, repo,
806 	   worktree->base_commit_id);
807 	if (err)
808 		goto done;
809 
810 	err = got_object_id_by_path(&tree_id, repo,
811 	    worktree->base_commit_id, worktree->path_prefix);
812 	if (err)
813 		goto done;
814 
815 	err = got_object_open_as_tree(&tree, repo, tree_id);
816 	if (err)
817 		goto done;
818 
819 	diff_cb.diff_old_new = diff_old_new;
820 	diff_cb.diff_old = diff_old;
821 	diff_cb.diff_new = diff_new;
822 	arg.fileindex = fileindex;
823 	arg.worktree = worktree;
824 	arg.repo = repo;
825 	arg.progress_cb = progress_cb;
826 	arg.progress_arg = progress_arg;
827 	arg.cancel_cb = cancel_cb;
828 	arg.cancel_arg = cancel_arg;
829 	checkout_err = got_fileindex_diff_tree(fileindex, tree, repo,
830 	    &diff_cb, &arg);
831 
832 	/* Try to sync the fileindex back to disk in any case. */
833 	err = got_fileindex_write(fileindex, new_index);
834 	if (err)
835 		goto done;
836 
837 	if (rename(new_fileindex_path, fileindex_path) != 0) {
838 		err = got_error_from_errno();
839 		goto done;
840 	}
841 
842 	free(new_fileindex_path);
843 	new_fileindex_path = NULL;
844 
845 done:
846 	if (tree)
847 		got_object_tree_close(tree);
848 	if (commit)
849 		got_object_commit_close(commit);
850 	if (new_fileindex_path)
851 		unlink(new_fileindex_path);
852 	if (new_index)
853 		fclose(new_index);
854 	free(new_fileindex_path);
855 	free(fileindex_path);
856 	got_fileindex_free(fileindex);
857 	if (checkout_err)
858 		err = checkout_err;
859 	unlockerr = lock_worktree(worktree, LOCK_SH);
860 	if (unlockerr && err == NULL)
861 		err = unlockerr;
862 	return err;
863 }