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1 | #include "../git-compat-util.h" | |
2 | #include "../copy.h" | |
3 | #include "../environment.h" | |
4 | #include "../gettext.h" | |
5 | #include "../hash.h" | |
6 | #include "../hex.h" | |
7 | #include "../refs.h" | |
8 | #include "refs-internal.h" | |
9 | #include "ref-cache.h" | |
10 | #include "packed-backend.h" | |
11 | #include "../ident.h" | |
12 | #include "../iterator.h" | |
13 | #include "../dir-iterator.h" | |
14 | #include "../lockfile.h" | |
15 | #include "../object.h" | |
16 | #include "../object-file.h" | |
17 | #include "../path.h" | |
18 | #include "../dir.h" | |
19 | #include "../chdir-notify.h" | |
20 | #include "../setup.h" | |
21 | #include "../wrapper.h" | |
22 | #include "../write-or-die.h" | |
23 | #include "../revision.h" | |
24 | #include <wildmatch.h> | |
25 | ||
26 | /* | |
27 | * This backend uses the following flags in `ref_update::flags` for | |
28 | * internal bookkeeping purposes. Their numerical values must not | |
29 | * conflict with REF_NO_DEREF, REF_FORCE_CREATE_REFLOG, REF_HAVE_NEW, | |
30 | * or REF_HAVE_OLD, which are also stored in `ref_update::flags`. | |
31 | */ | |
32 | ||
33 | /* | |
34 | * Used as a flag in ref_update::flags when a loose ref is being | |
35 | * pruned. This flag must only be used when REF_NO_DEREF is set. | |
36 | */ | |
37 | #define REF_IS_PRUNING (1 << 4) | |
38 | ||
39 | /* | |
40 | * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken | |
41 | * refs (i.e., because the reference is about to be deleted anyway). | |
42 | */ | |
43 | #define REF_DELETING (1 << 5) | |
44 | ||
45 | /* | |
46 | * Used as a flag in ref_update::flags when the lockfile needs to be | |
47 | * committed. | |
48 | */ | |
49 | #define REF_NEEDS_COMMIT (1 << 6) | |
50 | ||
51 | /* | |
52 | * Used as a flag in ref_update::flags when the ref_update was via an | |
53 | * update to HEAD. | |
54 | */ | |
55 | #define REF_UPDATE_VIA_HEAD (1 << 8) | |
56 | ||
57 | /* | |
58 | * Used as a flag in ref_update::flags when a reference has been | |
59 | * deleted and the ref's parent directories may need cleanup. | |
60 | */ | |
61 | #define REF_DELETED_RMDIR (1 << 9) | |
62 | ||
63 | struct ref_lock { | |
64 | char *ref_name; | |
65 | struct lock_file lk; | |
66 | struct object_id old_oid; | |
67 | }; | |
68 | ||
69 | struct files_ref_store { | |
70 | struct ref_store base; | |
71 | unsigned int store_flags; | |
72 | ||
73 | char *gitcommondir; | |
74 | ||
75 | struct ref_cache *loose; | |
76 | ||
77 | struct ref_store *packed_ref_store; | |
78 | }; | |
79 | ||
80 | static void clear_loose_ref_cache(struct files_ref_store *refs) | |
81 | { | |
82 | if (refs->loose) { | |
83 | free_ref_cache(refs->loose); | |
84 | refs->loose = NULL; | |
85 | } | |
86 | } | |
87 | ||
88 | /* | |
89 | * Create a new submodule ref cache and add it to the internal | |
90 | * set of caches. | |
91 | */ | |
92 | static struct ref_store *files_ref_store_create(struct repository *repo, | |
93 | const char *gitdir, | |
94 | unsigned int flags) | |
95 | { | |
96 | struct files_ref_store *refs = xcalloc(1, sizeof(*refs)); | |
97 | struct ref_store *ref_store = (struct ref_store *)refs; | |
98 | struct strbuf sb = STRBUF_INIT; | |
99 | ||
100 | base_ref_store_init(ref_store, repo, gitdir, &refs_be_files); | |
101 | refs->store_flags = flags; | |
102 | get_common_dir_noenv(&sb, gitdir); | |
103 | refs->gitcommondir = strbuf_detach(&sb, NULL); | |
104 | refs->packed_ref_store = | |
105 | packed_ref_store_create(repo, refs->gitcommondir, flags); | |
106 | ||
107 | chdir_notify_reparent("files-backend $GIT_DIR", &refs->base.gitdir); | |
108 | chdir_notify_reparent("files-backend $GIT_COMMONDIR", | |
109 | &refs->gitcommondir); | |
110 | ||
111 | return ref_store; | |
112 | } | |
113 | ||
114 | /* | |
115 | * Die if refs is not the main ref store. caller is used in any | |
116 | * necessary error messages. | |
117 | */ | |
118 | static void files_assert_main_repository(struct files_ref_store *refs, | |
119 | const char *caller) | |
120 | { | |
121 | if (refs->store_flags & REF_STORE_MAIN) | |
122 | return; | |
123 | ||
124 | BUG("operation %s only allowed for main ref store", caller); | |
125 | } | |
126 | ||
127 | /* | |
128 | * Downcast ref_store to files_ref_store. Die if ref_store is not a | |
129 | * files_ref_store. required_flags is compared with ref_store's | |
130 | * store_flags to ensure the ref_store has all required capabilities. | |
131 | * "caller" is used in any necessary error messages. | |
132 | */ | |
133 | static struct files_ref_store *files_downcast(struct ref_store *ref_store, | |
134 | unsigned int required_flags, | |
135 | const char *caller) | |
136 | { | |
137 | struct files_ref_store *refs; | |
138 | ||
139 | if (ref_store->be != &refs_be_files) | |
140 | BUG("ref_store is type \"%s\" not \"files\" in %s", | |
141 | ref_store->be->name, caller); | |
142 | ||
143 | refs = (struct files_ref_store *)ref_store; | |
144 | ||
145 | if ((refs->store_flags & required_flags) != required_flags) | |
146 | BUG("operation %s requires abilities 0x%x, but only have 0x%x", | |
147 | caller, required_flags, refs->store_flags); | |
148 | ||
149 | return refs; | |
150 | } | |
151 | ||
152 | static void files_reflog_path(struct files_ref_store *refs, | |
153 | struct strbuf *sb, | |
154 | const char *refname) | |
155 | { | |
156 | const char *bare_refname; | |
157 | const char *wtname; | |
158 | int wtname_len; | |
159 | enum ref_worktree_type wt_type = parse_worktree_ref( | |
160 | refname, &wtname, &wtname_len, &bare_refname); | |
161 | ||
162 | switch (wt_type) { | |
163 | case REF_WORKTREE_CURRENT: | |
164 | strbuf_addf(sb, "%s/logs/%s", refs->base.gitdir, refname); | |
165 | break; | |
166 | case REF_WORKTREE_SHARED: | |
167 | case REF_WORKTREE_MAIN: | |
168 | strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir, bare_refname); | |
169 | break; | |
170 | case REF_WORKTREE_OTHER: | |
171 | strbuf_addf(sb, "%s/worktrees/%.*s/logs/%s", refs->gitcommondir, | |
172 | wtname_len, wtname, bare_refname); | |
173 | break; | |
174 | default: | |
175 | BUG("unknown ref type %d of ref %s", wt_type, refname); | |
176 | } | |
177 | } | |
178 | ||
179 | static void files_ref_path(struct files_ref_store *refs, | |
180 | struct strbuf *sb, | |
181 | const char *refname) | |
182 | { | |
183 | const char *bare_refname; | |
184 | const char *wtname; | |
185 | int wtname_len; | |
186 | enum ref_worktree_type wt_type = parse_worktree_ref( | |
187 | refname, &wtname, &wtname_len, &bare_refname); | |
188 | switch (wt_type) { | |
189 | case REF_WORKTREE_CURRENT: | |
190 | strbuf_addf(sb, "%s/%s", refs->base.gitdir, refname); | |
191 | break; | |
192 | case REF_WORKTREE_OTHER: | |
193 | strbuf_addf(sb, "%s/worktrees/%.*s/%s", refs->gitcommondir, | |
194 | wtname_len, wtname, bare_refname); | |
195 | break; | |
196 | case REF_WORKTREE_SHARED: | |
197 | case REF_WORKTREE_MAIN: | |
198 | strbuf_addf(sb, "%s/%s", refs->gitcommondir, bare_refname); | |
199 | break; | |
200 | default: | |
201 | BUG("unknown ref type %d of ref %s", wt_type, refname); | |
202 | } | |
203 | } | |
204 | ||
205 | /* | |
206 | * Manually add refs/bisect, refs/rewritten and refs/worktree, which, being | |
207 | * per-worktree, might not appear in the directory listing for | |
208 | * refs/ in the main repo. | |
209 | */ | |
210 | static void add_per_worktree_entries_to_dir(struct ref_dir *dir, const char *dirname) | |
211 | { | |
212 | const char *prefixes[] = { "refs/bisect/", "refs/worktree/", "refs/rewritten/" }; | |
213 | int ip; | |
214 | ||
215 | if (strcmp(dirname, "refs/")) | |
216 | return; | |
217 | ||
218 | for (ip = 0; ip < ARRAY_SIZE(prefixes); ip++) { | |
219 | const char *prefix = prefixes[ip]; | |
220 | int prefix_len = strlen(prefix); | |
221 | struct ref_entry *child_entry; | |
222 | int pos; | |
223 | ||
224 | pos = search_ref_dir(dir, prefix, prefix_len); | |
225 | if (pos >= 0) | |
226 | continue; | |
227 | child_entry = create_dir_entry(dir->cache, prefix, prefix_len); | |
228 | add_entry_to_dir(dir, child_entry); | |
229 | } | |
230 | } | |
231 | ||
232 | /* | |
233 | * Read the loose references from the namespace dirname into dir | |
234 | * (without recursing). dirname must end with '/'. dir must be the | |
235 | * directory entry corresponding to dirname. | |
236 | */ | |
237 | static void loose_fill_ref_dir(struct ref_store *ref_store, | |
238 | struct ref_dir *dir, const char *dirname) | |
239 | { | |
240 | struct files_ref_store *refs = | |
241 | files_downcast(ref_store, REF_STORE_READ, "fill_ref_dir"); | |
242 | DIR *d; | |
243 | struct dirent *de; | |
244 | int dirnamelen = strlen(dirname); | |
245 | struct strbuf refname; | |
246 | struct strbuf path = STRBUF_INIT; | |
247 | ||
248 | files_ref_path(refs, &path, dirname); | |
249 | ||
250 | d = opendir(path.buf); | |
251 | if (!d) { | |
252 | strbuf_release(&path); | |
253 | return; | |
254 | } | |
255 | ||
256 | strbuf_init(&refname, dirnamelen + 257); | |
257 | strbuf_add(&refname, dirname, dirnamelen); | |
258 | ||
259 | while ((de = readdir(d)) != NULL) { | |
260 | struct object_id oid; | |
261 | int flag; | |
262 | unsigned char dtype; | |
263 | ||
264 | if (de->d_name[0] == '.') | |
265 | continue; | |
266 | if (ends_with(de->d_name, ".lock")) | |
267 | continue; | |
268 | strbuf_addstr(&refname, de->d_name); | |
269 | ||
270 | dtype = get_dtype(de, &path, 1); | |
271 | if (dtype == DT_DIR) { | |
272 | strbuf_addch(&refname, '/'); | |
273 | add_entry_to_dir(dir, | |
274 | create_dir_entry(dir->cache, refname.buf, | |
275 | refname.len)); | |
276 | } else if (dtype == DT_REG) { | |
277 | if (!refs_resolve_ref_unsafe(&refs->base, | |
278 | refname.buf, | |
279 | RESOLVE_REF_READING, | |
280 | &oid, &flag)) { | |
281 | oidclr(&oid); | |
282 | flag |= REF_ISBROKEN; | |
283 | } else if (is_null_oid(&oid)) { | |
284 | /* | |
285 | * It is so astronomically unlikely | |
286 | * that null_oid is the OID of an | |
287 | * actual object that we consider its | |
288 | * appearance in a loose reference | |
289 | * file to be repo corruption | |
290 | * (probably due to a software bug). | |
291 | */ | |
292 | flag |= REF_ISBROKEN; | |
293 | } | |
294 | ||
295 | if (check_refname_format(refname.buf, | |
296 | REFNAME_ALLOW_ONELEVEL)) { | |
297 | if (!refname_is_safe(refname.buf)) | |
298 | die("loose refname is dangerous: %s", refname.buf); | |
299 | oidclr(&oid); | |
300 | flag |= REF_BAD_NAME | REF_ISBROKEN; | |
301 | } | |
302 | add_entry_to_dir(dir, | |
303 | create_ref_entry(refname.buf, &oid, flag)); | |
304 | } | |
305 | strbuf_setlen(&refname, dirnamelen); | |
306 | } | |
307 | strbuf_release(&refname); | |
308 | strbuf_release(&path); | |
309 | closedir(d); | |
310 | ||
311 | add_per_worktree_entries_to_dir(dir, dirname); | |
312 | } | |
313 | ||
314 | static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs) | |
315 | { | |
316 | if (!refs->loose) { | |
317 | /* | |
318 | * Mark the top-level directory complete because we | |
319 | * are about to read the only subdirectory that can | |
320 | * hold references: | |
321 | */ | |
322 | refs->loose = create_ref_cache(&refs->base, loose_fill_ref_dir); | |
323 | ||
324 | /* We're going to fill the top level ourselves: */ | |
325 | refs->loose->root->flag &= ~REF_INCOMPLETE; | |
326 | ||
327 | /* | |
328 | * Add an incomplete entry for "refs/" (to be filled | |
329 | * lazily): | |
330 | */ | |
331 | add_entry_to_dir(get_ref_dir(refs->loose->root), | |
332 | create_dir_entry(refs->loose, "refs/", 5)); | |
333 | } | |
334 | return refs->loose; | |
335 | } | |
336 | ||
337 | static int read_ref_internal(struct ref_store *ref_store, const char *refname, | |
338 | struct object_id *oid, struct strbuf *referent, | |
339 | unsigned int *type, int *failure_errno, int skip_packed_refs) | |
340 | { | |
341 | struct files_ref_store *refs = | |
342 | files_downcast(ref_store, REF_STORE_READ, "read_raw_ref"); | |
343 | struct strbuf sb_contents = STRBUF_INIT; | |
344 | struct strbuf sb_path = STRBUF_INIT; | |
345 | const char *path; | |
346 | const char *buf; | |
347 | struct stat st; | |
348 | int fd; | |
349 | int ret = -1; | |
350 | int remaining_retries = 3; | |
351 | int myerr = 0; | |
352 | ||
353 | *type = 0; | |
354 | strbuf_reset(&sb_path); | |
355 | ||
356 | files_ref_path(refs, &sb_path, refname); | |
357 | ||
358 | path = sb_path.buf; | |
359 | ||
360 | stat_ref: | |
361 | /* | |
362 | * We might have to loop back here to avoid a race | |
363 | * condition: first we lstat() the file, then we try | |
364 | * to read it as a link or as a file. But if somebody | |
365 | * changes the type of the file (file <-> directory | |
366 | * <-> symlink) between the lstat() and reading, then | |
367 | * we don't want to report that as an error but rather | |
368 | * try again starting with the lstat(). | |
369 | * | |
370 | * We'll keep a count of the retries, though, just to avoid | |
371 | * any confusing situation sending us into an infinite loop. | |
372 | */ | |
373 | ||
374 | if (remaining_retries-- <= 0) | |
375 | goto out; | |
376 | ||
377 | if (lstat(path, &st) < 0) { | |
378 | int ignore_errno; | |
379 | myerr = errno; | |
380 | if (myerr != ENOENT || skip_packed_refs) | |
381 | goto out; | |
382 | if (refs_read_raw_ref(refs->packed_ref_store, refname, oid, | |
383 | referent, type, &ignore_errno)) { | |
384 | myerr = ENOENT; | |
385 | goto out; | |
386 | } | |
387 | ret = 0; | |
388 | goto out; | |
389 | } | |
390 | ||
391 | /* Follow "normalized" - ie "refs/.." symlinks by hand */ | |
392 | if (S_ISLNK(st.st_mode)) { | |
393 | strbuf_reset(&sb_contents); | |
394 | if (strbuf_readlink(&sb_contents, path, st.st_size) < 0) { | |
395 | myerr = errno; | |
396 | if (myerr == ENOENT || myerr == EINVAL) | |
397 | /* inconsistent with lstat; retry */ | |
398 | goto stat_ref; | |
399 | else | |
400 | goto out; | |
401 | } | |
402 | if (starts_with(sb_contents.buf, "refs/") && | |
403 | !check_refname_format(sb_contents.buf, 0)) { | |
404 | strbuf_swap(&sb_contents, referent); | |
405 | *type |= REF_ISSYMREF; | |
406 | ret = 0; | |
407 | goto out; | |
408 | } | |
409 | /* | |
410 | * It doesn't look like a refname; fall through to just | |
411 | * treating it like a non-symlink, and reading whatever it | |
412 | * points to. | |
413 | */ | |
414 | } | |
415 | ||
416 | /* Is it a directory? */ | |
417 | if (S_ISDIR(st.st_mode)) { | |
418 | int ignore_errno; | |
419 | /* | |
420 | * Even though there is a directory where the loose | |
421 | * ref is supposed to be, there could still be a | |
422 | * packed ref: | |
423 | */ | |
424 | if (skip_packed_refs || | |
425 | refs_read_raw_ref(refs->packed_ref_store, refname, oid, | |
426 | referent, type, &ignore_errno)) { | |
427 | myerr = EISDIR; | |
428 | goto out; | |
429 | } | |
430 | ret = 0; | |
431 | goto out; | |
432 | } | |
433 | ||
434 | /* | |
435 | * Anything else, just open it and try to use it as | |
436 | * a ref | |
437 | */ | |
438 | fd = open(path, O_RDONLY); | |
439 | if (fd < 0) { | |
440 | myerr = errno; | |
441 | if (myerr == ENOENT && !S_ISLNK(st.st_mode)) | |
442 | /* inconsistent with lstat; retry */ | |
443 | goto stat_ref; | |
444 | else | |
445 | goto out; | |
446 | } | |
447 | strbuf_reset(&sb_contents); | |
448 | if (strbuf_read(&sb_contents, fd, 256) < 0) { | |
449 | myerr = errno; | |
450 | close(fd); | |
451 | goto out; | |
452 | } | |
453 | close(fd); | |
454 | strbuf_rtrim(&sb_contents); | |
455 | buf = sb_contents.buf; | |
456 | ||
457 | ret = parse_loose_ref_contents(buf, oid, referent, type, &myerr); | |
458 | ||
459 | out: | |
460 | if (ret && !myerr) | |
461 | BUG("returning non-zero %d, should have set myerr!", ret); | |
462 | *failure_errno = myerr; | |
463 | ||
464 | strbuf_release(&sb_path); | |
465 | strbuf_release(&sb_contents); | |
466 | errno = 0; | |
467 | return ret; | |
468 | } | |
469 | ||
470 | static int files_read_raw_ref(struct ref_store *ref_store, const char *refname, | |
471 | struct object_id *oid, struct strbuf *referent, | |
472 | unsigned int *type, int *failure_errno) | |
473 | { | |
474 | return read_ref_internal(ref_store, refname, oid, referent, type, failure_errno, 0); | |
475 | } | |
476 | ||
477 | static int files_read_symbolic_ref(struct ref_store *ref_store, const char *refname, | |
478 | struct strbuf *referent) | |
479 | { | |
480 | struct object_id oid; | |
481 | int failure_errno, ret; | |
482 | unsigned int type; | |
483 | ||
484 | ret = read_ref_internal(ref_store, refname, &oid, referent, &type, &failure_errno, 1); | |
485 | if (ret) | |
486 | return ret; | |
487 | ||
488 | return !(type & REF_ISSYMREF); | |
489 | } | |
490 | ||
491 | int parse_loose_ref_contents(const char *buf, struct object_id *oid, | |
492 | struct strbuf *referent, unsigned int *type, | |
493 | int *failure_errno) | |
494 | { | |
495 | const char *p; | |
496 | if (skip_prefix(buf, "ref:", &buf)) { | |
497 | while (isspace(*buf)) | |
498 | buf++; | |
499 | ||
500 | strbuf_reset(referent); | |
501 | strbuf_addstr(referent, buf); | |
502 | *type |= REF_ISSYMREF; | |
503 | return 0; | |
504 | } | |
505 | ||
506 | /* | |
507 | * FETCH_HEAD has additional data after the sha. | |
508 | */ | |
509 | if (parse_oid_hex(buf, oid, &p) || | |
510 | (*p != '\0' && !isspace(*p))) { | |
511 | *type |= REF_ISBROKEN; | |
512 | *failure_errno = EINVAL; | |
513 | return -1; | |
514 | } | |
515 | return 0; | |
516 | } | |
517 | ||
518 | static void unlock_ref(struct ref_lock *lock) | |
519 | { | |
520 | rollback_lock_file(&lock->lk); | |
521 | free(lock->ref_name); | |
522 | free(lock); | |
523 | } | |
524 | ||
525 | /* | |
526 | * Lock refname, without following symrefs, and set *lock_p to point | |
527 | * at a newly-allocated lock object. Fill in lock->old_oid, referent, | |
528 | * and type similarly to read_raw_ref(). | |
529 | * | |
530 | * The caller must verify that refname is a "safe" reference name (in | |
531 | * the sense of refname_is_safe()) before calling this function. | |
532 | * | |
533 | * If the reference doesn't already exist, verify that refname doesn't | |
534 | * have a D/F conflict with any existing references. extras and skip | |
535 | * are passed to refs_verify_refname_available() for this check. | |
536 | * | |
537 | * If mustexist is not set and the reference is not found or is | |
538 | * broken, lock the reference anyway but clear old_oid. | |
539 | * | |
540 | * Return 0 on success. On failure, write an error message to err and | |
541 | * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR. | |
542 | * | |
543 | * Implementation note: This function is basically | |
544 | * | |
545 | * lock reference | |
546 | * read_raw_ref() | |
547 | * | |
548 | * but it includes a lot more code to | |
549 | * - Deal with possible races with other processes | |
550 | * - Avoid calling refs_verify_refname_available() when it can be | |
551 | * avoided, namely if we were successfully able to read the ref | |
552 | * - Generate informative error messages in the case of failure | |
553 | */ | |
554 | static int lock_raw_ref(struct files_ref_store *refs, | |
555 | const char *refname, int mustexist, | |
556 | const struct string_list *extras, | |
557 | struct ref_lock **lock_p, | |
558 | struct strbuf *referent, | |
559 | unsigned int *type, | |
560 | struct strbuf *err) | |
561 | { | |
562 | struct ref_lock *lock; | |
563 | struct strbuf ref_file = STRBUF_INIT; | |
564 | int attempts_remaining = 3; | |
565 | int ret = TRANSACTION_GENERIC_ERROR; | |
566 | int failure_errno; | |
567 | ||
568 | assert(err); | |
569 | files_assert_main_repository(refs, "lock_raw_ref"); | |
570 | ||
571 | *type = 0; | |
572 | ||
573 | /* First lock the file so it can't change out from under us. */ | |
574 | ||
575 | *lock_p = CALLOC_ARRAY(lock, 1); | |
576 | ||
577 | lock->ref_name = xstrdup(refname); | |
578 | files_ref_path(refs, &ref_file, refname); | |
579 | ||
580 | retry: | |
581 | switch (safe_create_leading_directories(ref_file.buf)) { | |
582 | case SCLD_OK: | |
583 | break; /* success */ | |
584 | case SCLD_EXISTS: | |
585 | /* | |
586 | * Suppose refname is "refs/foo/bar". We just failed | |
587 | * to create the containing directory, "refs/foo", | |
588 | * because there was a non-directory in the way. This | |
589 | * indicates a D/F conflict, probably because of | |
590 | * another reference such as "refs/foo". There is no | |
591 | * reason to expect this error to be transitory. | |
592 | */ | |
593 | if (refs_verify_refname_available(&refs->base, refname, | |
594 | extras, NULL, err)) { | |
595 | if (mustexist) { | |
596 | /* | |
597 | * To the user the relevant error is | |
598 | * that the "mustexist" reference is | |
599 | * missing: | |
600 | */ | |
601 | strbuf_reset(err); | |
602 | strbuf_addf(err, "unable to resolve reference '%s'", | |
603 | refname); | |
604 | } else { | |
605 | /* | |
606 | * The error message set by | |
607 | * refs_verify_refname_available() is | |
608 | * OK. | |
609 | */ | |
610 | ret = TRANSACTION_NAME_CONFLICT; | |
611 | } | |
612 | } else { | |
613 | /* | |
614 | * The file that is in the way isn't a loose | |
615 | * reference. Report it as a low-level | |
616 | * failure. | |
617 | */ | |
618 | strbuf_addf(err, "unable to create lock file %s.lock; " | |
619 | "non-directory in the way", | |
620 | ref_file.buf); | |
621 | } | |
622 | goto error_return; | |
623 | case SCLD_VANISHED: | |
624 | /* Maybe another process was tidying up. Try again. */ | |
625 | if (--attempts_remaining > 0) | |
626 | goto retry; | |
627 | /* fall through */ | |
628 | default: | |
629 | strbuf_addf(err, "unable to create directory for %s", | |
630 | ref_file.buf); | |
631 | goto error_return; | |
632 | } | |
633 | ||
634 | if (hold_lock_file_for_update_timeout( | |
635 | &lock->lk, ref_file.buf, LOCK_NO_DEREF, | |
636 | get_files_ref_lock_timeout_ms()) < 0) { | |
637 | int myerr = errno; | |
638 | errno = 0; | |
639 | if (myerr == ENOENT && --attempts_remaining > 0) { | |
640 | /* | |
641 | * Maybe somebody just deleted one of the | |
642 | * directories leading to ref_file. Try | |
643 | * again: | |
644 | */ | |
645 | goto retry; | |
646 | } else { | |
647 | unable_to_lock_message(ref_file.buf, myerr, err); | |
648 | goto error_return; | |
649 | } | |
650 | } | |
651 | ||
652 | /* | |
653 | * Now we hold the lock and can read the reference without | |
654 | * fear that its value will change. | |
655 | */ | |
656 | ||
657 | if (files_read_raw_ref(&refs->base, refname, &lock->old_oid, referent, | |
658 | type, &failure_errno)) { | |
659 | if (failure_errno == ENOENT) { | |
660 | if (mustexist) { | |
661 | /* Garden variety missing reference. */ | |
662 | strbuf_addf(err, "unable to resolve reference '%s'", | |
663 | refname); | |
664 | goto error_return; | |
665 | } else { | |
666 | /* | |
667 | * Reference is missing, but that's OK. We | |
668 | * know that there is not a conflict with | |
669 | * another loose reference because | |
670 | * (supposing that we are trying to lock | |
671 | * reference "refs/foo/bar"): | |
672 | * | |
673 | * - We were successfully able to create | |
674 | * the lockfile refs/foo/bar.lock, so we | |
675 | * know there cannot be a loose reference | |
676 | * named "refs/foo". | |
677 | * | |
678 | * - We got ENOENT and not EISDIR, so we | |
679 | * know that there cannot be a loose | |
680 | * reference named "refs/foo/bar/baz". | |
681 | */ | |
682 | } | |
683 | } else if (failure_errno == EISDIR) { | |
684 | /* | |
685 | * There is a directory in the way. It might have | |
686 | * contained references that have been deleted. If | |
687 | * we don't require that the reference already | |
688 | * exists, try to remove the directory so that it | |
689 | * doesn't cause trouble when we want to rename the | |
690 | * lockfile into place later. | |
691 | */ | |
692 | if (mustexist) { | |
693 | /* Garden variety missing reference. */ | |
694 | strbuf_addf(err, "unable to resolve reference '%s'", | |
695 | refname); | |
696 | goto error_return; | |
697 | } else if (remove_dir_recursively(&ref_file, | |
698 | REMOVE_DIR_EMPTY_ONLY)) { | |
699 | if (refs_verify_refname_available( | |
700 | &refs->base, refname, | |
701 | extras, NULL, err)) { | |
702 | /* | |
703 | * The error message set by | |
704 | * verify_refname_available() is OK. | |
705 | */ | |
706 | ret = TRANSACTION_NAME_CONFLICT; | |
707 | goto error_return; | |
708 | } else { | |
709 | /* | |
710 | * We can't delete the directory, | |
711 | * but we also don't know of any | |
712 | * references that it should | |
713 | * contain. | |
714 | */ | |
715 | strbuf_addf(err, "there is a non-empty directory '%s' " | |
716 | "blocking reference '%s'", | |
717 | ref_file.buf, refname); | |
718 | goto error_return; | |
719 | } | |
720 | } | |
721 | } else if (failure_errno == EINVAL && (*type & REF_ISBROKEN)) { | |
722 | strbuf_addf(err, "unable to resolve reference '%s': " | |
723 | "reference broken", refname); | |
724 | goto error_return; | |
725 | } else { | |
726 | strbuf_addf(err, "unable to resolve reference '%s': %s", | |
727 | refname, strerror(failure_errno)); | |
728 | goto error_return; | |
729 | } | |
730 | ||
731 | /* | |
732 | * If the ref did not exist and we are creating it, | |
733 | * make sure there is no existing packed ref that | |
734 | * conflicts with refname: | |
735 | */ | |
736 | if (refs_verify_refname_available( | |
737 | refs->packed_ref_store, refname, | |
738 | extras, NULL, err)) | |
739 | goto error_return; | |
740 | } | |
741 | ||
742 | ret = 0; | |
743 | goto out; | |
744 | ||
745 | error_return: | |
746 | unlock_ref(lock); | |
747 | *lock_p = NULL; | |
748 | ||
749 | out: | |
750 | strbuf_release(&ref_file); | |
751 | return ret; | |
752 | } | |
753 | ||
754 | struct files_ref_iterator { | |
755 | struct ref_iterator base; | |
756 | ||
757 | struct ref_iterator *iter0; | |
758 | struct repository *repo; | |
759 | unsigned int flags; | |
760 | }; | |
761 | ||
762 | static int files_ref_iterator_advance(struct ref_iterator *ref_iterator) | |
763 | { | |
764 | struct files_ref_iterator *iter = | |
765 | (struct files_ref_iterator *)ref_iterator; | |
766 | int ok; | |
767 | ||
768 | while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) { | |
769 | if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY && | |
770 | parse_worktree_ref(iter->iter0->refname, NULL, NULL, | |
771 | NULL) != REF_WORKTREE_CURRENT) | |
772 | continue; | |
773 | ||
774 | if ((iter->flags & DO_FOR_EACH_OMIT_DANGLING_SYMREFS) && | |
775 | (iter->iter0->flags & REF_ISSYMREF) && | |
776 | (iter->iter0->flags & REF_ISBROKEN)) | |
777 | continue; | |
778 | ||
779 | if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) && | |
780 | !ref_resolves_to_object(iter->iter0->refname, | |
781 | iter->repo, | |
782 | iter->iter0->oid, | |
783 | iter->iter0->flags)) | |
784 | continue; | |
785 | ||
786 | iter->base.refname = iter->iter0->refname; | |
787 | iter->base.oid = iter->iter0->oid; | |
788 | iter->base.flags = iter->iter0->flags; | |
789 | return ITER_OK; | |
790 | } | |
791 | ||
792 | iter->iter0 = NULL; | |
793 | if (ref_iterator_abort(ref_iterator) != ITER_DONE) | |
794 | ok = ITER_ERROR; | |
795 | ||
796 | return ok; | |
797 | } | |
798 | ||
799 | static int files_ref_iterator_peel(struct ref_iterator *ref_iterator, | |
800 | struct object_id *peeled) | |
801 | { | |
802 | struct files_ref_iterator *iter = | |
803 | (struct files_ref_iterator *)ref_iterator; | |
804 | ||
805 | return ref_iterator_peel(iter->iter0, peeled); | |
806 | } | |
807 | ||
808 | static int files_ref_iterator_abort(struct ref_iterator *ref_iterator) | |
809 | { | |
810 | struct files_ref_iterator *iter = | |
811 | (struct files_ref_iterator *)ref_iterator; | |
812 | int ok = ITER_DONE; | |
813 | ||
814 | if (iter->iter0) | |
815 | ok = ref_iterator_abort(iter->iter0); | |
816 | ||
817 | base_ref_iterator_free(ref_iterator); | |
818 | return ok; | |
819 | } | |
820 | ||
821 | static struct ref_iterator_vtable files_ref_iterator_vtable = { | |
822 | .advance = files_ref_iterator_advance, | |
823 | .peel = files_ref_iterator_peel, | |
824 | .abort = files_ref_iterator_abort, | |
825 | }; | |
826 | ||
827 | static struct ref_iterator *files_ref_iterator_begin( | |
828 | struct ref_store *ref_store, | |
829 | const char *prefix, const char **exclude_patterns, | |
830 | unsigned int flags) | |
831 | { | |
832 | struct files_ref_store *refs; | |
833 | struct ref_iterator *loose_iter, *packed_iter, *overlay_iter; | |
834 | struct files_ref_iterator *iter; | |
835 | struct ref_iterator *ref_iterator; | |
836 | unsigned int required_flags = REF_STORE_READ; | |
837 | ||
838 | if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) | |
839 | required_flags |= REF_STORE_ODB; | |
840 | ||
841 | refs = files_downcast(ref_store, required_flags, "ref_iterator_begin"); | |
842 | ||
843 | /* | |
844 | * We must make sure that all loose refs are read before | |
845 | * accessing the packed-refs file; this avoids a race | |
846 | * condition if loose refs are migrated to the packed-refs | |
847 | * file by a simultaneous process, but our in-memory view is | |
848 | * from before the migration. We ensure this as follows: | |
849 | * First, we call start the loose refs iteration with its | |
850 | * `prime_ref` argument set to true. This causes the loose | |
851 | * references in the subtree to be pre-read into the cache. | |
852 | * (If they've already been read, that's OK; we only need to | |
853 | * guarantee that they're read before the packed refs, not | |
854 | * *how much* before.) After that, we call | |
855 | * packed_ref_iterator_begin(), which internally checks | |
856 | * whether the packed-ref cache is up to date with what is on | |
857 | * disk, and re-reads it if not. | |
858 | */ | |
859 | ||
860 | loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), | |
861 | prefix, ref_store->repo, 1); | |
862 | ||
863 | /* | |
864 | * The packed-refs file might contain broken references, for | |
865 | * example an old version of a reference that points at an | |
866 | * object that has since been garbage-collected. This is OK as | |
867 | * long as there is a corresponding loose reference that | |
868 | * overrides it, and we don't want to emit an error message in | |
869 | * this case. So ask the packed_ref_store for all of its | |
870 | * references, and (if needed) do our own check for broken | |
871 | * ones in files_ref_iterator_advance(), after we have merged | |
872 | * the packed and loose references. | |
873 | */ | |
874 | packed_iter = refs_ref_iterator_begin( | |
875 | refs->packed_ref_store, prefix, exclude_patterns, 0, | |
876 | DO_FOR_EACH_INCLUDE_BROKEN); | |
877 | ||
878 | overlay_iter = overlay_ref_iterator_begin(loose_iter, packed_iter); | |
879 | ||
880 | CALLOC_ARRAY(iter, 1); | |
881 | ref_iterator = &iter->base; | |
882 | base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable, | |
883 | overlay_iter->ordered); | |
884 | iter->iter0 = overlay_iter; | |
885 | iter->repo = ref_store->repo; | |
886 | iter->flags = flags; | |
887 | ||
888 | return ref_iterator; | |
889 | } | |
890 | ||
891 | /* | |
892 | * Callback function for raceproof_create_file(). This function is | |
893 | * expected to do something that makes dirname(path) permanent despite | |
894 | * the fact that other processes might be cleaning up empty | |
895 | * directories at the same time. Usually it will create a file named | |
896 | * path, but alternatively it could create another file in that | |
897 | * directory, or even chdir() into that directory. The function should | |
898 | * return 0 if the action was completed successfully. On error, it | |
899 | * should return a nonzero result and set errno. | |
900 | * raceproof_create_file() treats two errno values specially: | |
901 | * | |
902 | * - ENOENT -- dirname(path) does not exist. In this case, | |
903 | * raceproof_create_file() tries creating dirname(path) | |
904 | * (and any parent directories, if necessary) and calls | |
905 | * the function again. | |
906 | * | |
907 | * - EISDIR -- the file already exists and is a directory. In this | |
908 | * case, raceproof_create_file() removes the directory if | |
909 | * it is empty (and recursively any empty directories that | |
910 | * it contains) and calls the function again. | |
911 | * | |
912 | * Any other errno causes raceproof_create_file() to fail with the | |
913 | * callback's return value and errno. | |
914 | * | |
915 | * Obviously, this function should be OK with being called again if it | |
916 | * fails with ENOENT or EISDIR. In other scenarios it will not be | |
917 | * called again. | |
918 | */ | |
919 | typedef int create_file_fn(const char *path, void *cb); | |
920 | ||
921 | /* | |
922 | * Create a file in dirname(path) by calling fn, creating leading | |
923 | * directories if necessary. Retry a few times in case we are racing | |
924 | * with another process that is trying to clean up the directory that | |
925 | * contains path. See the documentation for create_file_fn for more | |
926 | * details. | |
927 | * | |
928 | * Return the value and set the errno that resulted from the most | |
929 | * recent call of fn. fn is always called at least once, and will be | |
930 | * called more than once if it returns ENOENT or EISDIR. | |
931 | */ | |
932 | static int raceproof_create_file(const char *path, create_file_fn fn, void *cb) | |
933 | { | |
934 | /* | |
935 | * The number of times we will try to remove empty directories | |
936 | * in the way of path. This is only 1 because if another | |
937 | * process is racily creating directories that conflict with | |
938 | * us, we don't want to fight against them. | |
939 | */ | |
940 | int remove_directories_remaining = 1; | |
941 | ||
942 | /* | |
943 | * The number of times that we will try to create the | |
944 | * directories containing path. We are willing to attempt this | |
945 | * more than once, because another process could be trying to | |
946 | * clean up empty directories at the same time as we are | |
947 | * trying to create them. | |
948 | */ | |
949 | int create_directories_remaining = 3; | |
950 | ||
951 | /* A scratch copy of path, filled lazily if we need it: */ | |
952 | struct strbuf path_copy = STRBUF_INIT; | |
953 | ||
954 | int ret, save_errno; | |
955 | ||
956 | /* Sanity check: */ | |
957 | assert(*path); | |
958 | ||
959 | retry_fn: | |
960 | ret = fn(path, cb); | |
961 | save_errno = errno; | |
962 | if (!ret) | |
963 | goto out; | |
964 | ||
965 | if (errno == EISDIR && remove_directories_remaining-- > 0) { | |
966 | /* | |
967 | * A directory is in the way. Maybe it is empty; try | |
968 | * to remove it: | |
969 | */ | |
970 | if (!path_copy.len) | |
971 | strbuf_addstr(&path_copy, path); | |
972 | ||
973 | if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY)) | |
974 | goto retry_fn; | |
975 | } else if (errno == ENOENT && create_directories_remaining-- > 0) { | |
976 | /* | |
977 | * Maybe the containing directory didn't exist, or | |
978 | * maybe it was just deleted by a process that is | |
979 | * racing with us to clean up empty directories. Try | |
980 | * to create it: | |
981 | */ | |
982 | enum scld_error scld_result; | |
983 | ||
984 | if (!path_copy.len) | |
985 | strbuf_addstr(&path_copy, path); | |
986 | ||
987 | do { | |
988 | scld_result = safe_create_leading_directories(path_copy.buf); | |
989 | if (scld_result == SCLD_OK) | |
990 | goto retry_fn; | |
991 | } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0); | |
992 | } | |
993 | ||
994 | out: | |
995 | strbuf_release(&path_copy); | |
996 | errno = save_errno; | |
997 | return ret; | |
998 | } | |
999 | ||
1000 | static int remove_empty_directories(struct strbuf *path) | |
1001 | { | |
1002 | /* | |
1003 | * we want to create a file but there is a directory there; | |
1004 | * if that is an empty directory (or a directory that contains | |
1005 | * only empty directories), remove them. | |
1006 | */ | |
1007 | return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY); | |
1008 | } | |
1009 | ||
1010 | static int create_reflock(const char *path, void *cb) | |
1011 | { | |
1012 | struct lock_file *lk = cb; | |
1013 | ||
1014 | return hold_lock_file_for_update_timeout( | |
1015 | lk, path, LOCK_NO_DEREF, | |
1016 | get_files_ref_lock_timeout_ms()) < 0 ? -1 : 0; | |
1017 | } | |
1018 | ||
1019 | /* | |
1020 | * Locks a ref returning the lock on success and NULL on failure. | |
1021 | */ | |
1022 | static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs, | |
1023 | const char *refname, | |
1024 | struct strbuf *err) | |
1025 | { | |
1026 | struct strbuf ref_file = STRBUF_INIT; | |
1027 | struct ref_lock *lock; | |
1028 | ||
1029 | files_assert_main_repository(refs, "lock_ref_oid_basic"); | |
1030 | assert(err); | |
1031 | ||
1032 | CALLOC_ARRAY(lock, 1); | |
1033 | ||
1034 | files_ref_path(refs, &ref_file, refname); | |
1035 | ||
1036 | /* | |
1037 | * If the ref did not exist and we are creating it, make sure | |
1038 | * there is no existing packed ref whose name begins with our | |
1039 | * refname, nor a packed ref whose name is a proper prefix of | |
1040 | * our refname. | |
1041 | */ | |
1042 | if (is_null_oid(&lock->old_oid) && | |
1043 | refs_verify_refname_available(refs->packed_ref_store, refname, | |
1044 | NULL, NULL, err)) | |
1045 | goto error_return; | |
1046 | ||
1047 | lock->ref_name = xstrdup(refname); | |
1048 | ||
1049 | if (raceproof_create_file(ref_file.buf, create_reflock, &lock->lk)) { | |
1050 | unable_to_lock_message(ref_file.buf, errno, err); | |
1051 | goto error_return; | |
1052 | } | |
1053 | ||
1054 | if (!refs_resolve_ref_unsafe(&refs->base, lock->ref_name, 0, | |
1055 | &lock->old_oid, NULL)) | |
1056 | oidclr(&lock->old_oid); | |
1057 | goto out; | |
1058 | ||
1059 | error_return: | |
1060 | unlock_ref(lock); | |
1061 | lock = NULL; | |
1062 | ||
1063 | out: | |
1064 | strbuf_release(&ref_file); | |
1065 | return lock; | |
1066 | } | |
1067 | ||
1068 | struct ref_to_prune { | |
1069 | struct ref_to_prune *next; | |
1070 | struct object_id oid; | |
1071 | char name[FLEX_ARRAY]; | |
1072 | }; | |
1073 | ||
1074 | enum { | |
1075 | REMOVE_EMPTY_PARENTS_REF = 0x01, | |
1076 | REMOVE_EMPTY_PARENTS_REFLOG = 0x02 | |
1077 | }; | |
1078 | ||
1079 | /* | |
1080 | * Remove empty parent directories associated with the specified | |
1081 | * reference and/or its reflog, but spare [logs/]refs/ and immediate | |
1082 | * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or | |
1083 | * REMOVE_EMPTY_PARENTS_REFLOG. | |
1084 | */ | |
1085 | static void try_remove_empty_parents(struct files_ref_store *refs, | |
1086 | const char *refname, | |
1087 | unsigned int flags) | |
1088 | { | |
1089 | struct strbuf buf = STRBUF_INIT; | |
1090 | struct strbuf sb = STRBUF_INIT; | |
1091 | char *p, *q; | |
1092 | int i; | |
1093 | ||
1094 | strbuf_addstr(&buf, refname); | |
1095 | p = buf.buf; | |
1096 | for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */ | |
1097 | while (*p && *p != '/') | |
1098 | p++; | |
1099 | /* tolerate duplicate slashes; see check_refname_format() */ | |
1100 | while (*p == '/') | |
1101 | p++; | |
1102 | } | |
1103 | q = buf.buf + buf.len; | |
1104 | while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) { | |
1105 | while (q > p && *q != '/') | |
1106 | q--; | |
1107 | while (q > p && *(q-1) == '/') | |
1108 | q--; | |
1109 | if (q == p) | |
1110 | break; | |
1111 | strbuf_setlen(&buf, q - buf.buf); | |
1112 | ||
1113 | strbuf_reset(&sb); | |
1114 | files_ref_path(refs, &sb, buf.buf); | |
1115 | if ((flags & REMOVE_EMPTY_PARENTS_REF) && rmdir(sb.buf)) | |
1116 | flags &= ~REMOVE_EMPTY_PARENTS_REF; | |
1117 | ||
1118 | strbuf_reset(&sb); | |
1119 | files_reflog_path(refs, &sb, buf.buf); | |
1120 | if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) && rmdir(sb.buf)) | |
1121 | flags &= ~REMOVE_EMPTY_PARENTS_REFLOG; | |
1122 | } | |
1123 | strbuf_release(&buf); | |
1124 | strbuf_release(&sb); | |
1125 | } | |
1126 | ||
1127 | /* make sure nobody touched the ref, and unlink */ | |
1128 | static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r) | |
1129 | { | |
1130 | struct ref_transaction *transaction; | |
1131 | struct strbuf err = STRBUF_INIT; | |
1132 | int ret = -1; | |
1133 | ||
1134 | if (check_refname_format(r->name, 0)) | |
1135 | return; | |
1136 | ||
1137 | transaction = ref_store_transaction_begin(&refs->base, &err); | |
1138 | if (!transaction) | |
1139 | goto cleanup; | |
1140 | ref_transaction_add_update( | |
1141 | transaction, r->name, | |
1142 | REF_NO_DEREF | REF_HAVE_NEW | REF_HAVE_OLD | REF_IS_PRUNING, | |
1143 | null_oid(), &r->oid, NULL); | |
1144 | if (ref_transaction_commit(transaction, &err)) | |
1145 | goto cleanup; | |
1146 | ||
1147 | ret = 0; | |
1148 | ||
1149 | cleanup: | |
1150 | if (ret) | |
1151 | error("%s", err.buf); | |
1152 | strbuf_release(&err); | |
1153 | ref_transaction_free(transaction); | |
1154 | return; | |
1155 | } | |
1156 | ||
1157 | /* | |
1158 | * Prune the loose versions of the references in the linked list | |
1159 | * `*refs_to_prune`, freeing the entries in the list as we go. | |
1160 | */ | |
1161 | static void prune_refs(struct files_ref_store *refs, struct ref_to_prune **refs_to_prune) | |
1162 | { | |
1163 | while (*refs_to_prune) { | |
1164 | struct ref_to_prune *r = *refs_to_prune; | |
1165 | *refs_to_prune = r->next; | |
1166 | prune_ref(refs, r); | |
1167 | free(r); | |
1168 | } | |
1169 | } | |
1170 | ||
1171 | /* | |
1172 | * Return true if the specified reference should be packed. | |
1173 | */ | |
1174 | static int should_pack_ref(const char *refname, | |
1175 | const struct object_id *oid, unsigned int ref_flags, | |
1176 | struct pack_refs_opts *opts) | |
1177 | { | |
1178 | struct string_list_item *item; | |
1179 | ||
1180 | /* Do not pack per-worktree refs: */ | |
1181 | if (parse_worktree_ref(refname, NULL, NULL, NULL) != | |
1182 | REF_WORKTREE_SHARED) | |
1183 | return 0; | |
1184 | ||
1185 | /* Do not pack symbolic refs: */ | |
1186 | if (ref_flags & REF_ISSYMREF) | |
1187 | return 0; | |
1188 | ||
1189 | /* Do not pack broken refs: */ | |
1190 | if (!ref_resolves_to_object(refname, the_repository, oid, ref_flags)) | |
1191 | return 0; | |
1192 | ||
1193 | if (ref_excluded(opts->exclusions, refname)) | |
1194 | return 0; | |
1195 | ||
1196 | for_each_string_list_item(item, opts->includes) | |
1197 | if (!wildmatch(item->string, refname, 0)) | |
1198 | return 1; | |
1199 | ||
1200 | return 0; | |
1201 | } | |
1202 | ||
1203 | static int files_pack_refs(struct ref_store *ref_store, | |
1204 | struct pack_refs_opts *opts) | |
1205 | { | |
1206 | struct files_ref_store *refs = | |
1207 | files_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB, | |
1208 | "pack_refs"); | |
1209 | struct ref_iterator *iter; | |
1210 | int ok; | |
1211 | struct ref_to_prune *refs_to_prune = NULL; | |
1212 | struct strbuf err = STRBUF_INIT; | |
1213 | struct ref_transaction *transaction; | |
1214 | ||
1215 | transaction = ref_store_transaction_begin(refs->packed_ref_store, &err); | |
1216 | if (!transaction) | |
1217 | return -1; | |
1218 | ||
1219 | packed_refs_lock(refs->packed_ref_store, LOCK_DIE_ON_ERROR, &err); | |
1220 | ||
1221 | iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), NULL, | |
1222 | the_repository, 0); | |
1223 | while ((ok = ref_iterator_advance(iter)) == ITER_OK) { | |
1224 | /* | |
1225 | * If the loose reference can be packed, add an entry | |
1226 | * in the packed ref cache. If the reference should be | |
1227 | * pruned, also add it to refs_to_prune. | |
1228 | */ | |
1229 | if (!should_pack_ref(iter->refname, iter->oid, iter->flags, opts)) | |
1230 | continue; | |
1231 | ||
1232 | /* | |
1233 | * Add a reference creation for this reference to the | |
1234 | * packed-refs transaction: | |
1235 | */ | |
1236 | if (ref_transaction_update(transaction, iter->refname, | |
1237 | iter->oid, NULL, | |
1238 | REF_NO_DEREF, NULL, &err)) | |
1239 | die("failure preparing to create packed reference %s: %s", | |
1240 | iter->refname, err.buf); | |
1241 | ||
1242 | /* Schedule the loose reference for pruning if requested. */ | |
1243 | if ((opts->flags & PACK_REFS_PRUNE)) { | |
1244 | struct ref_to_prune *n; | |
1245 | FLEX_ALLOC_STR(n, name, iter->refname); | |
1246 | oidcpy(&n->oid, iter->oid); | |
1247 | n->next = refs_to_prune; | |
1248 | refs_to_prune = n; | |
1249 | } | |
1250 | } | |
1251 | if (ok != ITER_DONE) | |
1252 | die("error while iterating over references"); | |
1253 | ||
1254 | if (ref_transaction_commit(transaction, &err)) | |
1255 | die("unable to write new packed-refs: %s", err.buf); | |
1256 | ||
1257 | ref_transaction_free(transaction); | |
1258 | ||
1259 | packed_refs_unlock(refs->packed_ref_store); | |
1260 | ||
1261 | prune_refs(refs, &refs_to_prune); | |
1262 | strbuf_release(&err); | |
1263 | return 0; | |
1264 | } | |
1265 | ||
1266 | /* | |
1267 | * People using contrib's git-new-workdir have .git/logs/refs -> | |
1268 | * /some/other/path/.git/logs/refs, and that may live on another device. | |
1269 | * | |
1270 | * IOW, to avoid cross device rename errors, the temporary renamed log must | |
1271 | * live into logs/refs. | |
1272 | */ | |
1273 | #define TMP_RENAMED_LOG "refs/.tmp-renamed-log" | |
1274 | ||
1275 | struct rename_cb { | |
1276 | const char *tmp_renamed_log; | |
1277 | int true_errno; | |
1278 | }; | |
1279 | ||
1280 | static int rename_tmp_log_callback(const char *path, void *cb_data) | |
1281 | { | |
1282 | struct rename_cb *cb = cb_data; | |
1283 | ||
1284 | if (rename(cb->tmp_renamed_log, path)) { | |
1285 | /* | |
1286 | * rename(a, b) when b is an existing directory ought | |
1287 | * to result in ISDIR, but Solaris 5.8 gives ENOTDIR. | |
1288 | * Sheesh. Record the true errno for error reporting, | |
1289 | * but report EISDIR to raceproof_create_file() so | |
1290 | * that it knows to retry. | |
1291 | */ | |
1292 | cb->true_errno = errno; | |
1293 | if (errno == ENOTDIR) | |
1294 | errno = EISDIR; | |
1295 | return -1; | |
1296 | } else { | |
1297 | return 0; | |
1298 | } | |
1299 | } | |
1300 | ||
1301 | static int rename_tmp_log(struct files_ref_store *refs, const char *newrefname) | |
1302 | { | |
1303 | struct strbuf path = STRBUF_INIT; | |
1304 | struct strbuf tmp = STRBUF_INIT; | |
1305 | struct rename_cb cb; | |
1306 | int ret; | |
1307 | ||
1308 | files_reflog_path(refs, &path, newrefname); | |
1309 | files_reflog_path(refs, &tmp, TMP_RENAMED_LOG); | |
1310 | cb.tmp_renamed_log = tmp.buf; | |
1311 | ret = raceproof_create_file(path.buf, rename_tmp_log_callback, &cb); | |
1312 | if (ret) { | |
1313 | if (errno == EISDIR) | |
1314 | error("directory not empty: %s", path.buf); | |
1315 | else | |
1316 | error("unable to move logfile %s to %s: %s", | |
1317 | tmp.buf, path.buf, | |
1318 | strerror(cb.true_errno)); | |
1319 | } | |
1320 | ||
1321 | strbuf_release(&path); | |
1322 | strbuf_release(&tmp); | |
1323 | return ret; | |
1324 | } | |
1325 | ||
1326 | static int write_ref_to_lockfile(struct ref_lock *lock, | |
1327 | const struct object_id *oid, | |
1328 | int skip_oid_verification, struct strbuf *err); | |
1329 | static int commit_ref_update(struct files_ref_store *refs, | |
1330 | struct ref_lock *lock, | |
1331 | const struct object_id *oid, const char *logmsg, | |
1332 | struct strbuf *err); | |
1333 | ||
1334 | /* | |
1335 | * Emit a better error message than lockfile.c's | |
1336 | * unable_to_lock_message() would in case there is a D/F conflict with | |
1337 | * another existing reference. If there would be a conflict, emit an error | |
1338 | * message and return false; otherwise, return true. | |
1339 | * | |
1340 | * Note that this function is not safe against all races with other | |
1341 | * processes, and that's not its job. We'll emit a more verbose error on D/f | |
1342 | * conflicts if we get past it into lock_ref_oid_basic(). | |
1343 | */ | |
1344 | static int refs_rename_ref_available(struct ref_store *refs, | |
1345 | const char *old_refname, | |
1346 | const char *new_refname) | |
1347 | { | |
1348 | struct string_list skip = STRING_LIST_INIT_NODUP; | |
1349 | struct strbuf err = STRBUF_INIT; | |
1350 | int ok; | |
1351 | ||
1352 | string_list_insert(&skip, old_refname); | |
1353 | ok = !refs_verify_refname_available(refs, new_refname, | |
1354 | NULL, &skip, &err); | |
1355 | if (!ok) | |
1356 | error("%s", err.buf); | |
1357 | ||
1358 | string_list_clear(&skip, 0); | |
1359 | strbuf_release(&err); | |
1360 | return ok; | |
1361 | } | |
1362 | ||
1363 | static int files_copy_or_rename_ref(struct ref_store *ref_store, | |
1364 | const char *oldrefname, const char *newrefname, | |
1365 | const char *logmsg, int copy) | |
1366 | { | |
1367 | struct files_ref_store *refs = | |
1368 | files_downcast(ref_store, REF_STORE_WRITE, "rename_ref"); | |
1369 | struct object_id orig_oid; | |
1370 | int flag = 0, logmoved = 0; | |
1371 | struct ref_lock *lock; | |
1372 | struct stat loginfo; | |
1373 | struct strbuf sb_oldref = STRBUF_INIT; | |
1374 | struct strbuf sb_newref = STRBUF_INIT; | |
1375 | struct strbuf tmp_renamed_log = STRBUF_INIT; | |
1376 | int log, ret; | |
1377 | struct strbuf err = STRBUF_INIT; | |
1378 | ||
1379 | files_reflog_path(refs, &sb_oldref, oldrefname); | |
1380 | files_reflog_path(refs, &sb_newref, newrefname); | |
1381 | files_reflog_path(refs, &tmp_renamed_log, TMP_RENAMED_LOG); | |
1382 | ||
1383 | log = !lstat(sb_oldref.buf, &loginfo); | |
1384 | if (log && S_ISLNK(loginfo.st_mode)) { | |
1385 | ret = error("reflog for %s is a symlink", oldrefname); | |
1386 | goto out; | |
1387 | } | |
1388 | ||
1389 | if (!refs_resolve_ref_unsafe(&refs->base, oldrefname, | |
1390 | RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE, | |
1391 | &orig_oid, &flag)) { | |
1392 | ret = error("refname %s not found", oldrefname); | |
1393 | goto out; | |
1394 | } | |
1395 | ||
1396 | if (flag & REF_ISSYMREF) { | |
1397 | if (copy) | |
1398 | ret = error("refname %s is a symbolic ref, copying it is not supported", | |
1399 | oldrefname); | |
1400 | else | |
1401 | ret = error("refname %s is a symbolic ref, renaming it is not supported", | |
1402 | oldrefname); | |
1403 | goto out; | |
1404 | } | |
1405 | if (!refs_rename_ref_available(&refs->base, oldrefname, newrefname)) { | |
1406 | ret = 1; | |
1407 | goto out; | |
1408 | } | |
1409 | ||
1410 | if (!copy && log && rename(sb_oldref.buf, tmp_renamed_log.buf)) { | |
1411 | ret = error("unable to move logfile logs/%s to logs/"TMP_RENAMED_LOG": %s", | |
1412 | oldrefname, strerror(errno)); | |
1413 | goto out; | |
1414 | } | |
1415 | ||
1416 | if (copy && log && copy_file(tmp_renamed_log.buf, sb_oldref.buf, 0644)) { | |
1417 | ret = error("unable to copy logfile logs/%s to logs/"TMP_RENAMED_LOG": %s", | |
1418 | oldrefname, strerror(errno)); | |
1419 | goto out; | |
1420 | } | |
1421 | ||
1422 | if (!copy && refs_delete_ref(&refs->base, logmsg, oldrefname, | |
1423 | &orig_oid, REF_NO_DEREF)) { | |
1424 | error("unable to delete old %s", oldrefname); | |
1425 | goto rollback; | |
1426 | } | |
1427 | ||
1428 | /* | |
1429 | * Since we are doing a shallow lookup, oid is not the | |
1430 | * correct value to pass to delete_ref as old_oid. But that | |
1431 | * doesn't matter, because an old_oid check wouldn't add to | |
1432 | * the safety anyway; we want to delete the reference whatever | |
1433 | * its current value. | |
1434 | */ | |
1435 | if (!copy && refs_resolve_ref_unsafe(&refs->base, newrefname, | |
1436 | RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE, | |
1437 | NULL, NULL) && | |
1438 | refs_delete_ref(&refs->base, NULL, newrefname, | |
1439 | NULL, REF_NO_DEREF)) { | |
1440 | if (errno == EISDIR) { | |
1441 | struct strbuf path = STRBUF_INIT; | |
1442 | int result; | |
1443 | ||
1444 | files_ref_path(refs, &path, newrefname); | |
1445 | result = remove_empty_directories(&path); | |
1446 | strbuf_release(&path); | |
1447 | ||
1448 | if (result) { | |
1449 | error("Directory not empty: %s", newrefname); | |
1450 | goto rollback; | |
1451 | } | |
1452 | } else { | |
1453 | error("unable to delete existing %s", newrefname); | |
1454 | goto rollback; | |
1455 | } | |
1456 | } | |
1457 | ||
1458 | if (log && rename_tmp_log(refs, newrefname)) | |
1459 | goto rollback; | |
1460 | ||
1461 | logmoved = log; | |
1462 | ||
1463 | lock = lock_ref_oid_basic(refs, newrefname, &err); | |
1464 | if (!lock) { | |
1465 | if (copy) | |
1466 | error("unable to copy '%s' to '%s': %s", oldrefname, newrefname, err.buf); | |
1467 | else | |
1468 | error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf); | |
1469 | strbuf_release(&err); | |
1470 | goto rollback; | |
1471 | } | |
1472 | oidcpy(&lock->old_oid, &orig_oid); | |
1473 | ||
1474 | if (write_ref_to_lockfile(lock, &orig_oid, 0, &err) || | |
1475 | commit_ref_update(refs, lock, &orig_oid, logmsg, &err)) { | |
1476 | error("unable to write current sha1 into %s: %s", newrefname, err.buf); | |
1477 | strbuf_release(&err); | |
1478 | goto rollback; | |
1479 | } | |
1480 | ||
1481 | ret = 0; | |
1482 | goto out; | |
1483 | ||
1484 | rollback: | |
1485 | lock = lock_ref_oid_basic(refs, oldrefname, &err); | |
1486 | if (!lock) { | |
1487 | error("unable to lock %s for rollback: %s", oldrefname, err.buf); | |
1488 | strbuf_release(&err); | |
1489 | goto rollbacklog; | |
1490 | } | |
1491 | ||
1492 | flag = log_all_ref_updates; | |
1493 | log_all_ref_updates = LOG_REFS_NONE; | |
1494 | if (write_ref_to_lockfile(lock, &orig_oid, 0, &err) || | |
1495 | commit_ref_update(refs, lock, &orig_oid, NULL, &err)) { | |
1496 | error("unable to write current sha1 into %s: %s", oldrefname, err.buf); | |
1497 | strbuf_release(&err); | |
1498 | } | |
1499 | log_all_ref_updates = flag; | |
1500 | ||
1501 | rollbacklog: | |
1502 | if (logmoved && rename(sb_newref.buf, sb_oldref.buf)) | |
1503 | error("unable to restore logfile %s from %s: %s", | |
1504 | oldrefname, newrefname, strerror(errno)); | |
1505 | if (!logmoved && log && | |
1506 | rename(tmp_renamed_log.buf, sb_oldref.buf)) | |
1507 | error("unable to restore logfile %s from logs/"TMP_RENAMED_LOG": %s", | |
1508 | oldrefname, strerror(errno)); | |
1509 | ret = 1; | |
1510 | out: | |
1511 | strbuf_release(&sb_newref); | |
1512 | strbuf_release(&sb_oldref); | |
1513 | strbuf_release(&tmp_renamed_log); | |
1514 | ||
1515 | return ret; | |
1516 | } | |
1517 | ||
1518 | static int files_rename_ref(struct ref_store *ref_store, | |
1519 | const char *oldrefname, const char *newrefname, | |
1520 | const char *logmsg) | |
1521 | { | |
1522 | return files_copy_or_rename_ref(ref_store, oldrefname, | |
1523 | newrefname, logmsg, 0); | |
1524 | } | |
1525 | ||
1526 | static int files_copy_ref(struct ref_store *ref_store, | |
1527 | const char *oldrefname, const char *newrefname, | |
1528 | const char *logmsg) | |
1529 | { | |
1530 | return files_copy_or_rename_ref(ref_store, oldrefname, | |
1531 | newrefname, logmsg, 1); | |
1532 | } | |
1533 | ||
1534 | static int close_ref_gently(struct ref_lock *lock) | |
1535 | { | |
1536 | if (close_lock_file_gently(&lock->lk)) | |
1537 | return -1; | |
1538 | return 0; | |
1539 | } | |
1540 | ||
1541 | static int commit_ref(struct ref_lock *lock) | |
1542 | { | |
1543 | char *path = get_locked_file_path(&lock->lk); | |
1544 | struct stat st; | |
1545 | ||
1546 | if (!lstat(path, &st) && S_ISDIR(st.st_mode)) { | |
1547 | /* | |
1548 | * There is a directory at the path we want to rename | |
1549 | * the lockfile to. Hopefully it is empty; try to | |
1550 | * delete it. | |
1551 | */ | |
1552 | size_t len = strlen(path); | |
1553 | struct strbuf sb_path = STRBUF_INIT; | |
1554 | ||
1555 | strbuf_attach(&sb_path, path, len, len); | |
1556 | ||
1557 | /* | |
1558 | * If this fails, commit_lock_file() will also fail | |
1559 | * and will report the problem. | |
1560 | */ | |
1561 | remove_empty_directories(&sb_path); | |
1562 | strbuf_release(&sb_path); | |
1563 | } else { | |
1564 | free(path); | |
1565 | } | |
1566 | ||
1567 | if (commit_lock_file(&lock->lk)) | |
1568 | return -1; | |
1569 | return 0; | |
1570 | } | |
1571 | ||
1572 | static int open_or_create_logfile(const char *path, void *cb) | |
1573 | { | |
1574 | int *fd = cb; | |
1575 | ||
1576 | *fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666); | |
1577 | return (*fd < 0) ? -1 : 0; | |
1578 | } | |
1579 | ||
1580 | /* | |
1581 | * Create a reflog for a ref. If force_create = 0, only create the | |
1582 | * reflog for certain refs (those for which should_autocreate_reflog | |
1583 | * returns non-zero). Otherwise, create it regardless of the reference | |
1584 | * name. If the logfile already existed or was created, return 0 and | |
1585 | * set *logfd to the file descriptor opened for appending to the file. | |
1586 | * If no logfile exists and we decided not to create one, return 0 and | |
1587 | * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and | |
1588 | * return -1. | |
1589 | */ | |
1590 | static int log_ref_setup(struct files_ref_store *refs, | |
1591 | const char *refname, int force_create, | |
1592 | int *logfd, struct strbuf *err) | |
1593 | { | |
1594 | struct strbuf logfile_sb = STRBUF_INIT; | |
1595 | char *logfile; | |
1596 | ||
1597 | files_reflog_path(refs, &logfile_sb, refname); | |
1598 | logfile = strbuf_detach(&logfile_sb, NULL); | |
1599 | ||
1600 | if (force_create || should_autocreate_reflog(refname)) { | |
1601 | if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) { | |
1602 | if (errno == ENOENT) | |
1603 | strbuf_addf(err, "unable to create directory for '%s': " | |
1604 | "%s", logfile, strerror(errno)); | |
1605 | else if (errno == EISDIR) | |
1606 | strbuf_addf(err, "there are still logs under '%s'", | |
1607 | logfile); | |
1608 | else | |
1609 | strbuf_addf(err, "unable to append to '%s': %s", | |
1610 | logfile, strerror(errno)); | |
1611 | ||
1612 | goto error; | |
1613 | } | |
1614 | } else { | |
1615 | *logfd = open(logfile, O_APPEND | O_WRONLY); | |
1616 | if (*logfd < 0) { | |
1617 | if (errno == ENOENT || errno == EISDIR) { | |
1618 | /* | |
1619 | * The logfile doesn't already exist, | |
1620 | * but that is not an error; it only | |
1621 | * means that we won't write log | |
1622 | * entries to it. | |
1623 | */ | |
1624 | ; | |
1625 | } else { | |
1626 | strbuf_addf(err, "unable to append to '%s': %s", | |
1627 | logfile, strerror(errno)); | |
1628 | goto error; | |
1629 | } | |
1630 | } | |
1631 | } | |
1632 | ||
1633 | if (*logfd >= 0) | |
1634 | adjust_shared_perm(logfile); | |
1635 | ||
1636 | free(logfile); | |
1637 | return 0; | |
1638 | ||
1639 | error: | |
1640 | free(logfile); | |
1641 | return -1; | |
1642 | } | |
1643 | ||
1644 | static int files_create_reflog(struct ref_store *ref_store, const char *refname, | |
1645 | struct strbuf *err) | |
1646 | { | |
1647 | struct files_ref_store *refs = | |
1648 | files_downcast(ref_store, REF_STORE_WRITE, "create_reflog"); | |
1649 | int fd; | |
1650 | ||
1651 | if (log_ref_setup(refs, refname, 1, &fd, err)) | |
1652 | return -1; | |
1653 | ||
1654 | if (fd >= 0) | |
1655 | close(fd); | |
1656 | ||
1657 | return 0; | |
1658 | } | |
1659 | ||
1660 | static int log_ref_write_fd(int fd, const struct object_id *old_oid, | |
1661 | const struct object_id *new_oid, | |
1662 | const char *committer, const char *msg) | |
1663 | { | |
1664 | struct strbuf sb = STRBUF_INIT; | |
1665 | int ret = 0; | |
1666 | ||
1667 | strbuf_addf(&sb, "%s %s %s", oid_to_hex(old_oid), oid_to_hex(new_oid), committer); | |
1668 | if (msg && *msg) { | |
1669 | strbuf_addch(&sb, '\t'); | |
1670 | strbuf_addstr(&sb, msg); | |
1671 | } | |
1672 | strbuf_addch(&sb, '\n'); | |
1673 | if (write_in_full(fd, sb.buf, sb.len) < 0) | |
1674 | ret = -1; | |
1675 | strbuf_release(&sb); | |
1676 | return ret; | |
1677 | } | |
1678 | ||
1679 | static int files_log_ref_write(struct files_ref_store *refs, | |
1680 | const char *refname, const struct object_id *old_oid, | |
1681 | const struct object_id *new_oid, const char *msg, | |
1682 | int flags, struct strbuf *err) | |
1683 | { | |
1684 | int logfd, result; | |
1685 | ||
1686 | if (log_all_ref_updates == LOG_REFS_UNSET) | |
1687 | log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL; | |
1688 | ||
1689 | result = log_ref_setup(refs, refname, | |
1690 | flags & REF_FORCE_CREATE_REFLOG, | |
1691 | &logfd, err); | |
1692 | ||
1693 | if (result) | |
1694 | return result; | |
1695 | ||
1696 | if (logfd < 0) | |
1697 | return 0; | |
1698 | result = log_ref_write_fd(logfd, old_oid, new_oid, | |
1699 | git_committer_info(0), msg); | |
1700 | if (result) { | |
1701 | struct strbuf sb = STRBUF_INIT; | |
1702 | int save_errno = errno; | |
1703 | ||
1704 | files_reflog_path(refs, &sb, refname); | |
1705 | strbuf_addf(err, "unable to append to '%s': %s", | |
1706 | sb.buf, strerror(save_errno)); | |
1707 | strbuf_release(&sb); | |
1708 | close(logfd); | |
1709 | return -1; | |
1710 | } | |
1711 | if (close(logfd)) { | |
1712 | struct strbuf sb = STRBUF_INIT; | |
1713 | int save_errno = errno; | |
1714 | ||
1715 | files_reflog_path(refs, &sb, refname); | |
1716 | strbuf_addf(err, "unable to append to '%s': %s", | |
1717 | sb.buf, strerror(save_errno)); | |
1718 | strbuf_release(&sb); | |
1719 | return -1; | |
1720 | } | |
1721 | return 0; | |
1722 | } | |
1723 | ||
1724 | /* | |
1725 | * Write oid into the open lockfile, then close the lockfile. On | |
1726 | * errors, rollback the lockfile, fill in *err and return -1. | |
1727 | */ | |
1728 | static int write_ref_to_lockfile(struct ref_lock *lock, | |
1729 | const struct object_id *oid, | |
1730 | int skip_oid_verification, struct strbuf *err) | |
1731 | { | |
1732 | static char term = '\n'; | |
1733 | struct object *o; | |
1734 | int fd; | |
1735 | ||
1736 | if (!skip_oid_verification) { | |
1737 | o = parse_object(the_repository, oid); | |
1738 | if (!o) { | |
1739 | strbuf_addf( | |
1740 | err, | |
1741 | "trying to write ref '%s' with nonexistent object %s", | |
1742 | lock->ref_name, oid_to_hex(oid)); | |
1743 | unlock_ref(lock); | |
1744 | return -1; | |
1745 | } | |
1746 | if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) { | |
1747 | strbuf_addf( | |
1748 | err, | |
1749 | "trying to write non-commit object %s to branch '%s'", | |
1750 | oid_to_hex(oid), lock->ref_name); | |
1751 | unlock_ref(lock); | |
1752 | return -1; | |
1753 | } | |
1754 | } | |
1755 | fd = get_lock_file_fd(&lock->lk); | |
1756 | if (write_in_full(fd, oid_to_hex(oid), the_hash_algo->hexsz) < 0 || | |
1757 | write_in_full(fd, &term, 1) < 0 || | |
1758 | fsync_component(FSYNC_COMPONENT_REFERENCE, get_lock_file_fd(&lock->lk)) < 0 || | |
1759 | close_ref_gently(lock) < 0) { | |
1760 | strbuf_addf(err, | |
1761 | "couldn't write '%s'", get_lock_file_path(&lock->lk)); | |
1762 | unlock_ref(lock); | |
1763 | return -1; | |
1764 | } | |
1765 | return 0; | |
1766 | } | |
1767 | ||
1768 | /* | |
1769 | * Commit a change to a loose reference that has already been written | |
1770 | * to the loose reference lockfile. Also update the reflogs if | |
1771 | * necessary, using the specified lockmsg (which can be NULL). | |
1772 | */ | |
1773 | static int commit_ref_update(struct files_ref_store *refs, | |
1774 | struct ref_lock *lock, | |
1775 | const struct object_id *oid, const char *logmsg, | |
1776 | struct strbuf *err) | |
1777 | { | |
1778 | files_assert_main_repository(refs, "commit_ref_update"); | |
1779 | ||
1780 | clear_loose_ref_cache(refs); | |
1781 | if (files_log_ref_write(refs, lock->ref_name, | |
1782 | &lock->old_oid, oid, | |
1783 | logmsg, 0, err)) { | |
1784 | char *old_msg = strbuf_detach(err, NULL); | |
1785 | strbuf_addf(err, "cannot update the ref '%s': %s", | |
1786 | lock->ref_name, old_msg); | |
1787 | free(old_msg); | |
1788 | unlock_ref(lock); | |
1789 | return -1; | |
1790 | } | |
1791 | ||
1792 | if (strcmp(lock->ref_name, "HEAD") != 0) { | |
1793 | /* | |
1794 | * Special hack: If a branch is updated directly and HEAD | |
1795 | * points to it (may happen on the remote side of a push | |
1796 | * for example) then logically the HEAD reflog should be | |
1797 | * updated too. | |
1798 | * A generic solution implies reverse symref information, | |
1799 | * but finding all symrefs pointing to the given branch | |
1800 | * would be rather costly for this rare event (the direct | |
1801 | * update of a branch) to be worth it. So let's cheat and | |
1802 | * check with HEAD only which should cover 99% of all usage | |
1803 | * scenarios (even 100% of the default ones). | |
1804 | */ | |
1805 | int head_flag; | |
1806 | const char *head_ref; | |
1807 | ||
1808 | head_ref = refs_resolve_ref_unsafe(&refs->base, "HEAD", | |
1809 | RESOLVE_REF_READING, | |
1810 | NULL, &head_flag); | |
1811 | if (head_ref && (head_flag & REF_ISSYMREF) && | |
1812 | !strcmp(head_ref, lock->ref_name)) { | |
1813 | struct strbuf log_err = STRBUF_INIT; | |
1814 | if (files_log_ref_write(refs, "HEAD", | |
1815 | &lock->old_oid, oid, | |
1816 | logmsg, 0, &log_err)) { | |
1817 | error("%s", log_err.buf); | |
1818 | strbuf_release(&log_err); | |
1819 | } | |
1820 | } | |
1821 | } | |
1822 | ||
1823 | if (commit_ref(lock)) { | |
1824 | strbuf_addf(err, "couldn't set '%s'", lock->ref_name); | |
1825 | unlock_ref(lock); | |
1826 | return -1; | |
1827 | } | |
1828 | ||
1829 | unlock_ref(lock); | |
1830 | return 0; | |
1831 | } | |
1832 | ||
1833 | static int create_ref_symlink(struct ref_lock *lock, const char *target) | |
1834 | { | |
1835 | int ret = -1; | |
1836 | #ifndef NO_SYMLINK_HEAD | |
1837 | char *ref_path = get_locked_file_path(&lock->lk); | |
1838 | unlink(ref_path); | |
1839 | ret = symlink(target, ref_path); | |
1840 | free(ref_path); | |
1841 | ||
1842 | if (ret) | |
1843 | fprintf(stderr, "no symlink - falling back to symbolic ref\n"); | |
1844 | #endif | |
1845 | return ret; | |
1846 | } | |
1847 | ||
1848 | static void update_symref_reflog(struct files_ref_store *refs, | |
1849 | struct ref_lock *lock, const char *refname, | |
1850 | const char *target, const char *logmsg) | |
1851 | { | |
1852 | struct strbuf err = STRBUF_INIT; | |
1853 | struct object_id new_oid; | |
1854 | ||
1855 | if (logmsg && | |
1856 | refs_resolve_ref_unsafe(&refs->base, target, | |
1857 | RESOLVE_REF_READING, &new_oid, NULL) && | |
1858 | files_log_ref_write(refs, refname, &lock->old_oid, | |
1859 | &new_oid, logmsg, 0, &err)) { | |
1860 | error("%s", err.buf); | |
1861 | strbuf_release(&err); | |
1862 | } | |
1863 | } | |
1864 | ||
1865 | static int create_symref_locked(struct files_ref_store *refs, | |
1866 | struct ref_lock *lock, const char *refname, | |
1867 | const char *target, const char *logmsg) | |
1868 | { | |
1869 | if (prefer_symlink_refs && !create_ref_symlink(lock, target)) { | |
1870 | update_symref_reflog(refs, lock, refname, target, logmsg); | |
1871 | return 0; | |
1872 | } | |
1873 | ||
1874 | if (!fdopen_lock_file(&lock->lk, "w")) | |
1875 | return error("unable to fdopen %s: %s", | |
1876 | get_lock_file_path(&lock->lk), strerror(errno)); | |
1877 | ||
1878 | update_symref_reflog(refs, lock, refname, target, logmsg); | |
1879 | ||
1880 | /* no error check; commit_ref will check ferror */ | |
1881 | fprintf(get_lock_file_fp(&lock->lk), "ref: %s\n", target); | |
1882 | if (commit_ref(lock) < 0) | |
1883 | return error("unable to write symref for %s: %s", refname, | |
1884 | strerror(errno)); | |
1885 | return 0; | |
1886 | } | |
1887 | ||
1888 | static int files_create_symref(struct ref_store *ref_store, | |
1889 | const char *refname, const char *target, | |
1890 | const char *logmsg) | |
1891 | { | |
1892 | struct files_ref_store *refs = | |
1893 | files_downcast(ref_store, REF_STORE_WRITE, "create_symref"); | |
1894 | struct strbuf err = STRBUF_INIT; | |
1895 | struct ref_lock *lock; | |
1896 | int ret; | |
1897 | ||
1898 | lock = lock_ref_oid_basic(refs, refname, &err); | |
1899 | if (!lock) { | |
1900 | error("%s", err.buf); | |
1901 | strbuf_release(&err); | |
1902 | return -1; | |
1903 | } | |
1904 | ||
1905 | ret = create_symref_locked(refs, lock, refname, target, logmsg); | |
1906 | unlock_ref(lock); | |
1907 | return ret; | |
1908 | } | |
1909 | ||
1910 | static int files_reflog_exists(struct ref_store *ref_store, | |
1911 | const char *refname) | |
1912 | { | |
1913 | struct files_ref_store *refs = | |
1914 | files_downcast(ref_store, REF_STORE_READ, "reflog_exists"); | |
1915 | struct strbuf sb = STRBUF_INIT; | |
1916 | struct stat st; | |
1917 | int ret; | |
1918 | ||
1919 | files_reflog_path(refs, &sb, refname); | |
1920 | ret = !lstat(sb.buf, &st) && S_ISREG(st.st_mode); | |
1921 | strbuf_release(&sb); | |
1922 | return ret; | |
1923 | } | |
1924 | ||
1925 | static int files_delete_reflog(struct ref_store *ref_store, | |
1926 | const char *refname) | |
1927 | { | |
1928 | struct files_ref_store *refs = | |
1929 | files_downcast(ref_store, REF_STORE_WRITE, "delete_reflog"); | |
1930 | struct strbuf sb = STRBUF_INIT; | |
1931 | int ret; | |
1932 | ||
1933 | files_reflog_path(refs, &sb, refname); | |
1934 | ret = remove_path(sb.buf); | |
1935 | strbuf_release(&sb); | |
1936 | return ret; | |
1937 | } | |
1938 | ||
1939 | static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data) | |
1940 | { | |
1941 | struct object_id ooid, noid; | |
1942 | char *email_end, *message; | |
1943 | timestamp_t timestamp; | |
1944 | int tz; | |
1945 | const char *p = sb->buf; | |
1946 | ||
1947 | /* old SP new SP name <email> SP time TAB msg LF */ | |
1948 | if (!sb->len || sb->buf[sb->len - 1] != '\n' || | |
1949 | parse_oid_hex(p, &ooid, &p) || *p++ != ' ' || | |
1950 | parse_oid_hex(p, &noid, &p) || *p++ != ' ' || | |
1951 | !(email_end = strchr(p, '>')) || | |
1952 | email_end[1] != ' ' || | |
1953 | !(timestamp = parse_timestamp(email_end + 2, &message, 10)) || | |
1954 | !message || message[0] != ' ' || | |
1955 | (message[1] != '+' && message[1] != '-') || | |
1956 | !isdigit(message[2]) || !isdigit(message[3]) || | |
1957 | !isdigit(message[4]) || !isdigit(message[5])) | |
1958 | return 0; /* corrupt? */ | |
1959 | email_end[1] = '\0'; | |
1960 | tz = strtol(message + 1, NULL, 10); | |
1961 | if (message[6] != '\t') | |
1962 | message += 6; | |
1963 | else | |
1964 | message += 7; | |
1965 | return fn(&ooid, &noid, p, timestamp, tz, message, cb_data); | |
1966 | } | |
1967 | ||
1968 | static char *find_beginning_of_line(char *bob, char *scan) | |
1969 | { | |
1970 | while (bob < scan && *(--scan) != '\n') | |
1971 | ; /* keep scanning backwards */ | |
1972 | /* | |
1973 | * Return either beginning of the buffer, or LF at the end of | |
1974 | * the previous line. | |
1975 | */ | |
1976 | return scan; | |
1977 | } | |
1978 | ||
1979 | static int files_for_each_reflog_ent_reverse(struct ref_store *ref_store, | |
1980 | const char *refname, | |
1981 | each_reflog_ent_fn fn, | |
1982 | void *cb_data) | |
1983 | { | |
1984 | struct files_ref_store *refs = | |
1985 | files_downcast(ref_store, REF_STORE_READ, | |
1986 | "for_each_reflog_ent_reverse"); | |
1987 | struct strbuf sb = STRBUF_INIT; | |
1988 | FILE *logfp; | |
1989 | long pos; | |
1990 | int ret = 0, at_tail = 1; | |
1991 | ||
1992 | files_reflog_path(refs, &sb, refname); | |
1993 | logfp = fopen(sb.buf, "r"); | |
1994 | strbuf_release(&sb); | |
1995 | if (!logfp) | |
1996 | return -1; | |
1997 | ||
1998 | /* Jump to the end */ | |
1999 | if (fseek(logfp, 0, SEEK_END) < 0) | |
2000 | ret = error("cannot seek back reflog for %s: %s", | |
2001 | refname, strerror(errno)); | |
2002 | pos = ftell(logfp); | |
2003 | while (!ret && 0 < pos) { | |
2004 | int cnt; | |
2005 | size_t nread; | |
2006 | char buf[BUFSIZ]; | |
2007 | char *endp, *scanp; | |
2008 | ||
2009 | /* Fill next block from the end */ | |
2010 | cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos; | |
2011 | if (fseek(logfp, pos - cnt, SEEK_SET)) { | |
2012 | ret = error("cannot seek back reflog for %s: %s", | |
2013 | refname, strerror(errno)); | |
2014 | break; | |
2015 | } | |
2016 | nread = fread(buf, cnt, 1, logfp); | |
2017 | if (nread != 1) { | |
2018 | ret = error("cannot read %d bytes from reflog for %s: %s", | |
2019 | cnt, refname, strerror(errno)); | |
2020 | break; | |
2021 | } | |
2022 | pos -= cnt; | |
2023 | ||
2024 | scanp = endp = buf + cnt; | |
2025 | if (at_tail && scanp[-1] == '\n') | |
2026 | /* Looking at the final LF at the end of the file */ | |
2027 | scanp--; | |
2028 | at_tail = 0; | |
2029 | ||
2030 | while (buf < scanp) { | |
2031 | /* | |
2032 | * terminating LF of the previous line, or the beginning | |
2033 | * of the buffer. | |
2034 | */ | |
2035 | char *bp; | |
2036 | ||
2037 | bp = find_beginning_of_line(buf, scanp); | |
2038 | ||
2039 | if (*bp == '\n') { | |
2040 | /* | |
2041 | * The newline is the end of the previous line, | |
2042 | * so we know we have complete line starting | |
2043 | * at (bp + 1). Prefix it onto any prior data | |
2044 | * we collected for the line and process it. | |
2045 | */ | |
2046 | strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1)); | |
2047 | scanp = bp; | |
2048 | endp = bp + 1; | |
2049 | ret = show_one_reflog_ent(&sb, fn, cb_data); | |
2050 | strbuf_reset(&sb); | |
2051 | if (ret) | |
2052 | break; | |
2053 | } else if (!pos) { | |
2054 | /* | |
2055 | * We are at the start of the buffer, and the | |
2056 | * start of the file; there is no previous | |
2057 | * line, and we have everything for this one. | |
2058 | * Process it, and we can end the loop. | |
2059 | */ | |
2060 | strbuf_splice(&sb, 0, 0, buf, endp - buf); | |
2061 | ret = show_one_reflog_ent(&sb, fn, cb_data); | |
2062 | strbuf_reset(&sb); | |
2063 | break; | |
2064 | } | |
2065 | ||
2066 | if (bp == buf) { | |
2067 | /* | |
2068 | * We are at the start of the buffer, and there | |
2069 | * is more file to read backwards. Which means | |
2070 | * we are in the middle of a line. Note that we | |
2071 | * may get here even if *bp was a newline; that | |
2072 | * just means we are at the exact end of the | |
2073 | * previous line, rather than some spot in the | |
2074 | * middle. | |
2075 | * | |
2076 | * Save away what we have to be combined with | |
2077 | * the data from the next read. | |
2078 | */ | |
2079 | strbuf_splice(&sb, 0, 0, buf, endp - buf); | |
2080 | break; | |
2081 | } | |
2082 | } | |
2083 | ||
2084 | } | |
2085 | if (!ret && sb.len) | |
2086 | BUG("reverse reflog parser had leftover data"); | |
2087 | ||
2088 | fclose(logfp); | |
2089 | strbuf_release(&sb); | |
2090 | return ret; | |
2091 | } | |
2092 | ||
2093 | static int files_for_each_reflog_ent(struct ref_store *ref_store, | |
2094 | const char *refname, | |
2095 | each_reflog_ent_fn fn, void *cb_data) | |
2096 | { | |
2097 | struct files_ref_store *refs = | |
2098 | files_downcast(ref_store, REF_STORE_READ, | |
2099 | "for_each_reflog_ent"); | |
2100 | FILE *logfp; | |
2101 | struct strbuf sb = STRBUF_INIT; | |
2102 | int ret = 0; | |
2103 | ||
2104 | files_reflog_path(refs, &sb, refname); | |
2105 | logfp = fopen(sb.buf, "r"); | |
2106 | strbuf_release(&sb); | |
2107 | if (!logfp) | |
2108 | return -1; | |
2109 | ||
2110 | while (!ret && !strbuf_getwholeline(&sb, logfp, '\n')) | |
2111 | ret = show_one_reflog_ent(&sb, fn, cb_data); | |
2112 | fclose(logfp); | |
2113 | strbuf_release(&sb); | |
2114 | return ret; | |
2115 | } | |
2116 | ||
2117 | struct files_reflog_iterator { | |
2118 | struct ref_iterator base; | |
2119 | ||
2120 | struct ref_store *ref_store; | |
2121 | struct dir_iterator *dir_iterator; | |
2122 | struct object_id oid; | |
2123 | }; | |
2124 | ||
2125 | static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator) | |
2126 | { | |
2127 | struct files_reflog_iterator *iter = | |
2128 | (struct files_reflog_iterator *)ref_iterator; | |
2129 | struct dir_iterator *diter = iter->dir_iterator; | |
2130 | int ok; | |
2131 | ||
2132 | while ((ok = dir_iterator_advance(diter)) == ITER_OK) { | |
2133 | int flags; | |
2134 | ||
2135 | if (!S_ISREG(diter->st.st_mode)) | |
2136 | continue; | |
2137 | if (diter->basename[0] == '.') | |
2138 | continue; | |
2139 | if (ends_with(diter->basename, ".lock")) | |
2140 | continue; | |
2141 | ||
2142 | if (!refs_resolve_ref_unsafe(iter->ref_store, | |
2143 | diter->relative_path, 0, | |
2144 | &iter->oid, &flags)) { | |
2145 | error("bad ref for %s", diter->path.buf); | |
2146 | continue; | |
2147 | } | |
2148 | ||
2149 | iter->base.refname = diter->relative_path; | |
2150 | iter->base.oid = &iter->oid; | |
2151 | iter->base.flags = flags; | |
2152 | return ITER_OK; | |
2153 | } | |
2154 | ||
2155 | iter->dir_iterator = NULL; | |
2156 | if (ref_iterator_abort(ref_iterator) == ITER_ERROR) | |
2157 | ok = ITER_ERROR; | |
2158 | return ok; | |
2159 | } | |
2160 | ||
2161 | static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator UNUSED, | |
2162 | struct object_id *peeled UNUSED) | |
2163 | { | |
2164 | BUG("ref_iterator_peel() called for reflog_iterator"); | |
2165 | } | |
2166 | ||
2167 | static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator) | |
2168 | { | |
2169 | struct files_reflog_iterator *iter = | |
2170 | (struct files_reflog_iterator *)ref_iterator; | |
2171 | int ok = ITER_DONE; | |
2172 | ||
2173 | if (iter->dir_iterator) | |
2174 | ok = dir_iterator_abort(iter->dir_iterator); | |
2175 | ||
2176 | base_ref_iterator_free(ref_iterator); | |
2177 | return ok; | |
2178 | } | |
2179 | ||
2180 | static struct ref_iterator_vtable files_reflog_iterator_vtable = { | |
2181 | .advance = files_reflog_iterator_advance, | |
2182 | .peel = files_reflog_iterator_peel, | |
2183 | .abort = files_reflog_iterator_abort, | |
2184 | }; | |
2185 | ||
2186 | static struct ref_iterator *reflog_iterator_begin(struct ref_store *ref_store, | |
2187 | const char *gitdir) | |
2188 | { | |
2189 | struct dir_iterator *diter; | |
2190 | struct files_reflog_iterator *iter; | |
2191 | struct ref_iterator *ref_iterator; | |
2192 | struct strbuf sb = STRBUF_INIT; | |
2193 | ||
2194 | strbuf_addf(&sb, "%s/logs", gitdir); | |
2195 | ||
2196 | diter = dir_iterator_begin(sb.buf, 0); | |
2197 | if (!diter) { | |
2198 | strbuf_release(&sb); | |
2199 | return empty_ref_iterator_begin(); | |
2200 | } | |
2201 | ||
2202 | CALLOC_ARRAY(iter, 1); | |
2203 | ref_iterator = &iter->base; | |
2204 | ||
2205 | base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable, 0); | |
2206 | iter->dir_iterator = diter; | |
2207 | iter->ref_store = ref_store; | |
2208 | strbuf_release(&sb); | |
2209 | ||
2210 | return ref_iterator; | |
2211 | } | |
2212 | ||
2213 | static enum iterator_selection reflog_iterator_select( | |
2214 | struct ref_iterator *iter_worktree, | |
2215 | struct ref_iterator *iter_common, | |
2216 | void *cb_data UNUSED) | |
2217 | { | |
2218 | if (iter_worktree) { | |
2219 | /* | |
2220 | * We're a bit loose here. We probably should ignore | |
2221 | * common refs if they are accidentally added as | |
2222 | * per-worktree refs. | |
2223 | */ | |
2224 | return ITER_SELECT_0; | |
2225 | } else if (iter_common) { | |
2226 | if (parse_worktree_ref(iter_common->refname, NULL, NULL, | |
2227 | NULL) == REF_WORKTREE_SHARED) | |
2228 | return ITER_SELECT_1; | |
2229 | ||
2230 | /* | |
2231 | * The main ref store may contain main worktree's | |
2232 | * per-worktree refs, which should be ignored | |
2233 | */ | |
2234 | return ITER_SKIP_1; | |
2235 | } else | |
2236 | return ITER_DONE; | |
2237 | } | |
2238 | ||
2239 | static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store) | |
2240 | { | |
2241 | struct files_ref_store *refs = | |
2242 | files_downcast(ref_store, REF_STORE_READ, | |
2243 | "reflog_iterator_begin"); | |
2244 | ||
2245 | if (!strcmp(refs->base.gitdir, refs->gitcommondir)) { | |
2246 | return reflog_iterator_begin(ref_store, refs->gitcommondir); | |
2247 | } else { | |
2248 | return merge_ref_iterator_begin( | |
2249 | 0, reflog_iterator_begin(ref_store, refs->base.gitdir), | |
2250 | reflog_iterator_begin(ref_store, refs->gitcommondir), | |
2251 | reflog_iterator_select, refs); | |
2252 | } | |
2253 | } | |
2254 | ||
2255 | /* | |
2256 | * If update is a direct update of head_ref (the reference pointed to | |
2257 | * by HEAD), then add an extra REF_LOG_ONLY update for HEAD. | |
2258 | */ | |
2259 | static int split_head_update(struct ref_update *update, | |
2260 | struct ref_transaction *transaction, | |
2261 | const char *head_ref, | |
2262 | struct string_list *affected_refnames, | |
2263 | struct strbuf *err) | |
2264 | { | |
2265 | struct string_list_item *item; | |
2266 | struct ref_update *new_update; | |
2267 | ||
2268 | if ((update->flags & REF_LOG_ONLY) || | |
2269 | (update->flags & REF_IS_PRUNING) || | |
2270 | (update->flags & REF_UPDATE_VIA_HEAD)) | |
2271 | return 0; | |
2272 | ||
2273 | if (strcmp(update->refname, head_ref)) | |
2274 | return 0; | |
2275 | ||
2276 | /* | |
2277 | * First make sure that HEAD is not already in the | |
2278 | * transaction. This check is O(lg N) in the transaction | |
2279 | * size, but it happens at most once per transaction. | |
2280 | */ | |
2281 | if (string_list_has_string(affected_refnames, "HEAD")) { | |
2282 | /* An entry already existed */ | |
2283 | strbuf_addf(err, | |
2284 | "multiple updates for 'HEAD' (including one " | |
2285 | "via its referent '%s') are not allowed", | |
2286 | update->refname); | |
2287 | return TRANSACTION_NAME_CONFLICT; | |
2288 | } | |
2289 | ||
2290 | new_update = ref_transaction_add_update( | |
2291 | transaction, "HEAD", | |
2292 | update->flags | REF_LOG_ONLY | REF_NO_DEREF, | |
2293 | &update->new_oid, &update->old_oid, | |
2294 | update->msg); | |
2295 | ||
2296 | /* | |
2297 | * Add "HEAD". This insertion is O(N) in the transaction | |
2298 | * size, but it happens at most once per transaction. | |
2299 | * Add new_update->refname instead of a literal "HEAD". | |
2300 | */ | |
2301 | if (strcmp(new_update->refname, "HEAD")) | |
2302 | BUG("%s unexpectedly not 'HEAD'", new_update->refname); | |
2303 | item = string_list_insert(affected_refnames, new_update->refname); | |
2304 | item->util = new_update; | |
2305 | ||
2306 | return 0; | |
2307 | } | |
2308 | ||
2309 | /* | |
2310 | * update is for a symref that points at referent and doesn't have | |
2311 | * REF_NO_DEREF set. Split it into two updates: | |
2312 | * - The original update, but with REF_LOG_ONLY and REF_NO_DEREF set | |
2313 | * - A new, separate update for the referent reference | |
2314 | * Note that the new update will itself be subject to splitting when | |
2315 | * the iteration gets to it. | |
2316 | */ | |
2317 | static int split_symref_update(struct ref_update *update, | |
2318 | const char *referent, | |
2319 | struct ref_transaction *transaction, | |
2320 | struct string_list *affected_refnames, | |
2321 | struct strbuf *err) | |
2322 | { | |
2323 | struct string_list_item *item; | |
2324 | struct ref_update *new_update; | |
2325 | unsigned int new_flags; | |
2326 | ||
2327 | /* | |
2328 | * First make sure that referent is not already in the | |
2329 | * transaction. This check is O(lg N) in the transaction | |
2330 | * size, but it happens at most once per symref in a | |
2331 | * transaction. | |
2332 | */ | |
2333 | if (string_list_has_string(affected_refnames, referent)) { | |
2334 | /* An entry already exists */ | |
2335 | strbuf_addf(err, | |
2336 | "multiple updates for '%s' (including one " | |
2337 | "via symref '%s') are not allowed", | |
2338 | referent, update->refname); | |
2339 | return TRANSACTION_NAME_CONFLICT; | |
2340 | } | |
2341 | ||
2342 | new_flags = update->flags; | |
2343 | if (!strcmp(update->refname, "HEAD")) { | |
2344 | /* | |
2345 | * Record that the new update came via HEAD, so that | |
2346 | * when we process it, split_head_update() doesn't try | |
2347 | * to add another reflog update for HEAD. Note that | |
2348 | * this bit will be propagated if the new_update | |
2349 | * itself needs to be split. | |
2350 | */ | |
2351 | new_flags |= REF_UPDATE_VIA_HEAD; | |
2352 | } | |
2353 | ||
2354 | new_update = ref_transaction_add_update( | |
2355 | transaction, referent, new_flags, | |
2356 | &update->new_oid, &update->old_oid, | |
2357 | update->msg); | |
2358 | ||
2359 | new_update->parent_update = update; | |
2360 | ||
2361 | /* | |
2362 | * Change the symbolic ref update to log only. Also, it | |
2363 | * doesn't need to check its old OID value, as that will be | |
2364 | * done when new_update is processed. | |
2365 | */ | |
2366 | update->flags |= REF_LOG_ONLY | REF_NO_DEREF; | |
2367 | update->flags &= ~REF_HAVE_OLD; | |
2368 | ||
2369 | /* | |
2370 | * Add the referent. This insertion is O(N) in the transaction | |
2371 | * size, but it happens at most once per symref in a | |
2372 | * transaction. Make sure to add new_update->refname, which will | |
2373 | * be valid as long as affected_refnames is in use, and NOT | |
2374 | * referent, which might soon be freed by our caller. | |
2375 | */ | |
2376 | item = string_list_insert(affected_refnames, new_update->refname); | |
2377 | if (item->util) | |
2378 | BUG("%s unexpectedly found in affected_refnames", | |
2379 | new_update->refname); | |
2380 | item->util = new_update; | |
2381 | ||
2382 | return 0; | |
2383 | } | |
2384 | ||
2385 | /* | |
2386 | * Return the refname under which update was originally requested. | |
2387 | */ | |
2388 | static const char *original_update_refname(struct ref_update *update) | |
2389 | { | |
2390 | while (update->parent_update) | |
2391 | update = update->parent_update; | |
2392 | ||
2393 | return update->refname; | |
2394 | } | |
2395 | ||
2396 | /* | |
2397 | * Check whether the REF_HAVE_OLD and old_oid values stored in update | |
2398 | * are consistent with oid, which is the reference's current value. If | |
2399 | * everything is OK, return 0; otherwise, write an error message to | |
2400 | * err and return -1. | |
2401 | */ | |
2402 | static int check_old_oid(struct ref_update *update, struct object_id *oid, | |
2403 | struct strbuf *err) | |
2404 | { | |
2405 | if (!(update->flags & REF_HAVE_OLD) || | |
2406 | oideq(oid, &update->old_oid)) | |
2407 | return 0; | |
2408 | ||
2409 | if (is_null_oid(&update->old_oid)) | |
2410 | strbuf_addf(err, "cannot lock ref '%s': " | |
2411 | "reference already exists", | |
2412 | original_update_refname(update)); | |
2413 | else if (is_null_oid(oid)) | |
2414 | strbuf_addf(err, "cannot lock ref '%s': " | |
2415 | "reference is missing but expected %s", | |
2416 | original_update_refname(update), | |
2417 | oid_to_hex(&update->old_oid)); | |
2418 | else | |
2419 | strbuf_addf(err, "cannot lock ref '%s': " | |
2420 | "is at %s but expected %s", | |
2421 | original_update_refname(update), | |
2422 | oid_to_hex(oid), | |
2423 | oid_to_hex(&update->old_oid)); | |
2424 | ||
2425 | return -1; | |
2426 | } | |
2427 | ||
2428 | /* | |
2429 | * Prepare for carrying out update: | |
2430 | * - Lock the reference referred to by update. | |
2431 | * - Read the reference under lock. | |
2432 | * - Check that its old OID value (if specified) is correct, and in | |
2433 | * any case record it in update->lock->old_oid for later use when | |
2434 | * writing the reflog. | |
2435 | * - If it is a symref update without REF_NO_DEREF, split it up into a | |
2436 | * REF_LOG_ONLY update of the symref and add a separate update for | |
2437 | * the referent to transaction. | |
2438 | * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY | |
2439 | * update of HEAD. | |
2440 | */ | |
2441 | static int lock_ref_for_update(struct files_ref_store *refs, | |
2442 | struct ref_update *update, | |
2443 | struct ref_transaction *transaction, | |
2444 | const char *head_ref, | |
2445 | struct string_list *affected_refnames, | |
2446 | struct strbuf *err) | |
2447 | { | |
2448 | struct strbuf referent = STRBUF_INIT; | |
2449 | int mustexist = (update->flags & REF_HAVE_OLD) && | |
2450 | !is_null_oid(&update->old_oid); | |
2451 | int ret = 0; | |
2452 | struct ref_lock *lock; | |
2453 | ||
2454 | files_assert_main_repository(refs, "lock_ref_for_update"); | |
2455 | ||
2456 | if ((update->flags & REF_HAVE_NEW) && is_null_oid(&update->new_oid)) | |
2457 | update->flags |= REF_DELETING; | |
2458 | ||
2459 | if (head_ref) { | |
2460 | ret = split_head_update(update, transaction, head_ref, | |
2461 | affected_refnames, err); | |
2462 | if (ret) | |
2463 | goto out; | |
2464 | } | |
2465 | ||
2466 | ret = lock_raw_ref(refs, update->refname, mustexist, | |
2467 | affected_refnames, | |
2468 | &lock, &referent, | |
2469 | &update->type, err); | |
2470 | if (ret) { | |
2471 | char *reason; | |
2472 | ||
2473 | reason = strbuf_detach(err, NULL); | |
2474 | strbuf_addf(err, "cannot lock ref '%s': %s", | |
2475 | original_update_refname(update), reason); | |
2476 | free(reason); | |
2477 | goto out; | |
2478 | } | |
2479 | ||
2480 | update->backend_data = lock; | |
2481 | ||
2482 | if (update->type & REF_ISSYMREF) { | |
2483 | if (update->flags & REF_NO_DEREF) { | |
2484 | /* | |
2485 | * We won't be reading the referent as part of | |
2486 | * the transaction, so we have to read it here | |
2487 | * to record and possibly check old_oid: | |
2488 | */ | |
2489 | if (!refs_resolve_ref_unsafe(&refs->base, | |
2490 | referent.buf, 0, | |
2491 | &lock->old_oid, NULL)) { | |
2492 | if (update->flags & REF_HAVE_OLD) { | |
2493 | strbuf_addf(err, "cannot lock ref '%s': " | |
2494 | "error reading reference", | |
2495 | original_update_refname(update)); | |
2496 | ret = TRANSACTION_GENERIC_ERROR; | |
2497 | goto out; | |
2498 | } | |
2499 | } else if (check_old_oid(update, &lock->old_oid, err)) { | |
2500 | ret = TRANSACTION_GENERIC_ERROR; | |
2501 | goto out; | |
2502 | } | |
2503 | } else { | |
2504 | /* | |
2505 | * Create a new update for the reference this | |
2506 | * symref is pointing at. Also, we will record | |
2507 | * and verify old_oid for this update as part | |
2508 | * of processing the split-off update, so we | |
2509 | * don't have to do it here. | |
2510 | */ | |
2511 | ret = split_symref_update(update, | |
2512 | referent.buf, transaction, | |
2513 | affected_refnames, err); | |
2514 | if (ret) | |
2515 | goto out; | |
2516 | } | |
2517 | } else { | |
2518 | struct ref_update *parent_update; | |
2519 | ||
2520 | if (check_old_oid(update, &lock->old_oid, err)) { | |
2521 | ret = TRANSACTION_GENERIC_ERROR; | |
2522 | goto out; | |
2523 | } | |
2524 | ||
2525 | /* | |
2526 | * If this update is happening indirectly because of a | |
2527 | * symref update, record the old OID in the parent | |
2528 | * update: | |
2529 | */ | |
2530 | for (parent_update = update->parent_update; | |
2531 | parent_update; | |
2532 | parent_update = parent_update->parent_update) { | |
2533 | struct ref_lock *parent_lock = parent_update->backend_data; | |
2534 | oidcpy(&parent_lock->old_oid, &lock->old_oid); | |
2535 | } | |
2536 | } | |
2537 | ||
2538 | if ((update->flags & REF_HAVE_NEW) && | |
2539 | !(update->flags & REF_DELETING) && | |
2540 | !(update->flags & REF_LOG_ONLY)) { | |
2541 | if (!(update->type & REF_ISSYMREF) && | |
2542 | oideq(&lock->old_oid, &update->new_oid)) { | |
2543 | /* | |
2544 | * The reference already has the desired | |
2545 | * value, so we don't need to write it. | |
2546 | */ | |
2547 | } else if (write_ref_to_lockfile( | |
2548 | lock, &update->new_oid, | |
2549 | update->flags & REF_SKIP_OID_VERIFICATION, | |
2550 | err)) { | |
2551 | char *write_err = strbuf_detach(err, NULL); | |
2552 | ||
2553 | /* | |
2554 | * The lock was freed upon failure of | |
2555 | * write_ref_to_lockfile(): | |
2556 | */ | |
2557 | update->backend_data = NULL; | |
2558 | strbuf_addf(err, | |
2559 | "cannot update ref '%s': %s", | |
2560 | update->refname, write_err); | |
2561 | free(write_err); | |
2562 | ret = TRANSACTION_GENERIC_ERROR; | |
2563 | goto out; | |
2564 | } else { | |
2565 | update->flags |= REF_NEEDS_COMMIT; | |
2566 | } | |
2567 | } | |
2568 | if (!(update->flags & REF_NEEDS_COMMIT)) { | |
2569 | /* | |
2570 | * We didn't call write_ref_to_lockfile(), so | |
2571 | * the lockfile is still open. Close it to | |
2572 | * free up the file descriptor: | |
2573 | */ | |
2574 | if (close_ref_gently(lock)) { | |
2575 | strbuf_addf(err, "couldn't close '%s.lock'", | |
2576 | update->refname); | |
2577 | ret = TRANSACTION_GENERIC_ERROR; | |
2578 | goto out; | |
2579 | } | |
2580 | } | |
2581 | ||
2582 | out: | |
2583 | strbuf_release(&referent); | |
2584 | return ret; | |
2585 | } | |
2586 | ||
2587 | struct files_transaction_backend_data { | |
2588 | struct ref_transaction *packed_transaction; | |
2589 | int packed_refs_locked; | |
2590 | }; | |
2591 | ||
2592 | /* | |
2593 | * Unlock any references in `transaction` that are still locked, and | |
2594 | * mark the transaction closed. | |
2595 | */ | |
2596 | static void files_transaction_cleanup(struct files_ref_store *refs, | |
2597 | struct ref_transaction *transaction) | |
2598 | { | |
2599 | size_t i; | |
2600 | struct files_transaction_backend_data *backend_data = | |
2601 | transaction->backend_data; | |
2602 | struct strbuf err = STRBUF_INIT; | |
2603 | ||
2604 | for (i = 0; i < transaction->nr; i++) { | |
2605 | struct ref_update *update = transaction->updates[i]; | |
2606 | struct ref_lock *lock = update->backend_data; | |
2607 | ||
2608 | if (lock) { | |
2609 | unlock_ref(lock); | |
2610 | update->backend_data = NULL; | |
2611 | } | |
2612 | } | |
2613 | ||
2614 | if (backend_data) { | |
2615 | if (backend_data->packed_transaction && | |
2616 | ref_transaction_abort(backend_data->packed_transaction, &err)) { | |
2617 | error("error aborting transaction: %s", err.buf); | |
2618 | strbuf_release(&err); | |
2619 | } | |
2620 | ||
2621 | if (backend_data->packed_refs_locked) | |
2622 | packed_refs_unlock(refs->packed_ref_store); | |
2623 | ||
2624 | free(backend_data); | |
2625 | } | |
2626 | ||
2627 | transaction->state = REF_TRANSACTION_CLOSED; | |
2628 | } | |
2629 | ||
2630 | static int files_transaction_prepare(struct ref_store *ref_store, | |
2631 | struct ref_transaction *transaction, | |
2632 | struct strbuf *err) | |
2633 | { | |
2634 | struct files_ref_store *refs = | |
2635 | files_downcast(ref_store, REF_STORE_WRITE, | |
2636 | "ref_transaction_prepare"); | |
2637 | size_t i; | |
2638 | int ret = 0; | |
2639 | struct string_list affected_refnames = STRING_LIST_INIT_NODUP; | |
2640 | char *head_ref = NULL; | |
2641 | int head_type; | |
2642 | struct files_transaction_backend_data *backend_data; | |
2643 | struct ref_transaction *packed_transaction = NULL; | |
2644 | ||
2645 | assert(err); | |
2646 | ||
2647 | if (!transaction->nr) | |
2648 | goto cleanup; | |
2649 | ||
2650 | CALLOC_ARRAY(backend_data, 1); | |
2651 | transaction->backend_data = backend_data; | |
2652 | ||
2653 | /* | |
2654 | * Fail if a refname appears more than once in the | |
2655 | * transaction. (If we end up splitting up any updates using | |
2656 | * split_symref_update() or split_head_update(), those | |
2657 | * functions will check that the new updates don't have the | |
2658 | * same refname as any existing ones.) Also fail if any of the | |
2659 | * updates use REF_IS_PRUNING without REF_NO_DEREF. | |
2660 | */ | |
2661 | for (i = 0; i < transaction->nr; i++) { | |
2662 | struct ref_update *update = transaction->updates[i]; | |
2663 | struct string_list_item *item = | |
2664 | string_list_append(&affected_refnames, update->refname); | |
2665 | ||
2666 | if ((update->flags & REF_IS_PRUNING) && | |
2667 | !(update->flags & REF_NO_DEREF)) | |
2668 | BUG("REF_IS_PRUNING set without REF_NO_DEREF"); | |
2669 | ||
2670 | /* | |
2671 | * We store a pointer to update in item->util, but at | |
2672 | * the moment we never use the value of this field | |
2673 | * except to check whether it is non-NULL. | |
2674 | */ | |
2675 | item->util = update; | |
2676 | } | |
2677 | string_list_sort(&affected_refnames); | |
2678 | if (ref_update_reject_duplicates(&affected_refnames, err)) { | |
2679 | ret = TRANSACTION_GENERIC_ERROR; | |
2680 | goto cleanup; | |
2681 | } | |
2682 | ||
2683 | /* | |
2684 | * Special hack: If a branch is updated directly and HEAD | |
2685 | * points to it (may happen on the remote side of a push | |
2686 | * for example) then logically the HEAD reflog should be | |
2687 | * updated too. | |
2688 | * | |
2689 | * A generic solution would require reverse symref lookups, | |
2690 | * but finding all symrefs pointing to a given branch would be | |
2691 | * rather costly for this rare event (the direct update of a | |
2692 | * branch) to be worth it. So let's cheat and check with HEAD | |
2693 | * only, which should cover 99% of all usage scenarios (even | |
2694 | * 100% of the default ones). | |
2695 | * | |
2696 | * So if HEAD is a symbolic reference, then record the name of | |
2697 | * the reference that it points to. If we see an update of | |
2698 | * head_ref within the transaction, then split_head_update() | |
2699 | * arranges for the reflog of HEAD to be updated, too. | |
2700 | */ | |
2701 | head_ref = refs_resolve_refdup(ref_store, "HEAD", | |
2702 | RESOLVE_REF_NO_RECURSE, | |
2703 | NULL, &head_type); | |
2704 | ||
2705 | if (head_ref && !(head_type & REF_ISSYMREF)) { | |
2706 | FREE_AND_NULL(head_ref); | |
2707 | } | |
2708 | ||
2709 | /* | |
2710 | * Acquire all locks, verify old values if provided, check | |
2711 | * that new values are valid, and write new values to the | |
2712 | * lockfiles, ready to be activated. Only keep one lockfile | |
2713 | * open at a time to avoid running out of file descriptors. | |
2714 | * Note that lock_ref_for_update() might append more updates | |
2715 | * to the transaction. | |
2716 | */ | |
2717 | for (i = 0; i < transaction->nr; i++) { | |
2718 | struct ref_update *update = transaction->updates[i]; | |
2719 | ||
2720 | ret = lock_ref_for_update(refs, update, transaction, | |
2721 | head_ref, &affected_refnames, err); | |
2722 | if (ret) | |
2723 | goto cleanup; | |
2724 | ||
2725 | if (update->flags & REF_DELETING && | |
2726 | !(update->flags & REF_LOG_ONLY) && | |
2727 | !(update->flags & REF_IS_PRUNING)) { | |
2728 | /* | |
2729 | * This reference has to be deleted from | |
2730 | * packed-refs if it exists there. | |
2731 | */ | |
2732 | if (!packed_transaction) { | |
2733 | packed_transaction = ref_store_transaction_begin( | |
2734 | refs->packed_ref_store, err); | |
2735 | if (!packed_transaction) { | |
2736 | ret = TRANSACTION_GENERIC_ERROR; | |
2737 | goto cleanup; | |
2738 | } | |
2739 | ||
2740 | backend_data->packed_transaction = | |
2741 | packed_transaction; | |
2742 | } | |
2743 | ||
2744 | ref_transaction_add_update( | |
2745 | packed_transaction, update->refname, | |
2746 | REF_HAVE_NEW | REF_NO_DEREF, | |
2747 | &update->new_oid, NULL, | |
2748 | NULL); | |
2749 | } | |
2750 | } | |
2751 | ||
2752 | if (packed_transaction) { | |
2753 | if (packed_refs_lock(refs->packed_ref_store, 0, err)) { | |
2754 | ret = TRANSACTION_GENERIC_ERROR; | |
2755 | goto cleanup; | |
2756 | } | |
2757 | backend_data->packed_refs_locked = 1; | |
2758 | ||
2759 | if (is_packed_transaction_needed(refs->packed_ref_store, | |
2760 | packed_transaction)) { | |
2761 | ret = ref_transaction_prepare(packed_transaction, err); | |
2762 | /* | |
2763 | * A failure during the prepare step will abort | |
2764 | * itself, but not free. Do that now, and disconnect | |
2765 | * from the files_transaction so it does not try to | |
2766 | * abort us when we hit the cleanup code below. | |
2767 | */ | |
2768 | if (ret) { | |
2769 | ref_transaction_free(packed_transaction); | |
2770 | backend_data->packed_transaction = NULL; | |
2771 | } | |
2772 | } else { | |
2773 | /* | |
2774 | * We can skip rewriting the `packed-refs` | |
2775 | * file. But we do need to leave it locked, so | |
2776 | * that somebody else doesn't pack a reference | |
2777 | * that we are trying to delete. | |
2778 | * | |
2779 | * We need to disconnect our transaction from | |
2780 | * backend_data, since the abort (whether successful or | |
2781 | * not) will free it. | |
2782 | */ | |
2783 | backend_data->packed_transaction = NULL; | |
2784 | if (ref_transaction_abort(packed_transaction, err)) { | |
2785 | ret = TRANSACTION_GENERIC_ERROR; | |
2786 | goto cleanup; | |
2787 | } | |
2788 | } | |
2789 | } | |
2790 | ||
2791 | cleanup: | |
2792 | free(head_ref); | |
2793 | string_list_clear(&affected_refnames, 0); | |
2794 | ||
2795 | if (ret) | |
2796 | files_transaction_cleanup(refs, transaction); | |
2797 | else | |
2798 | transaction->state = REF_TRANSACTION_PREPARED; | |
2799 | ||
2800 | return ret; | |
2801 | } | |
2802 | ||
2803 | static int files_transaction_finish(struct ref_store *ref_store, | |
2804 | struct ref_transaction *transaction, | |
2805 | struct strbuf *err) | |
2806 | { | |
2807 | struct files_ref_store *refs = | |
2808 | files_downcast(ref_store, 0, "ref_transaction_finish"); | |
2809 | size_t i; | |
2810 | int ret = 0; | |
2811 | struct strbuf sb = STRBUF_INIT; | |
2812 | struct files_transaction_backend_data *backend_data; | |
2813 | struct ref_transaction *packed_transaction; | |
2814 | ||
2815 | ||
2816 | assert(err); | |
2817 | ||
2818 | if (!transaction->nr) { | |
2819 | transaction->state = REF_TRANSACTION_CLOSED; | |
2820 | return 0; | |
2821 | } | |
2822 | ||
2823 | backend_data = transaction->backend_data; | |
2824 | packed_transaction = backend_data->packed_transaction; | |
2825 | ||
2826 | /* Perform updates first so live commits remain referenced */ | |
2827 | for (i = 0; i < transaction->nr; i++) { | |
2828 | struct ref_update *update = transaction->updates[i]; | |
2829 | struct ref_lock *lock = update->backend_data; | |
2830 | ||
2831 | if (update->flags & REF_NEEDS_COMMIT || | |
2832 | update->flags & REF_LOG_ONLY) { | |
2833 | if (files_log_ref_write(refs, | |
2834 | lock->ref_name, | |
2835 | &lock->old_oid, | |
2836 | &update->new_oid, | |
2837 | update->msg, update->flags, | |
2838 | err)) { | |
2839 | char *old_msg = strbuf_detach(err, NULL); | |
2840 | ||
2841 | strbuf_addf(err, "cannot update the ref '%s': %s", | |
2842 | lock->ref_name, old_msg); | |
2843 | free(old_msg); | |
2844 | unlock_ref(lock); | |
2845 | update->backend_data = NULL; | |
2846 | ret = TRANSACTION_GENERIC_ERROR; | |
2847 | goto cleanup; | |
2848 | } | |
2849 | } | |
2850 | if (update->flags & REF_NEEDS_COMMIT) { | |
2851 | clear_loose_ref_cache(refs); | |
2852 | if (commit_ref(lock)) { | |
2853 | strbuf_addf(err, "couldn't set '%s'", lock->ref_name); | |
2854 | unlock_ref(lock); | |
2855 | update->backend_data = NULL; | |
2856 | ret = TRANSACTION_GENERIC_ERROR; | |
2857 | goto cleanup; | |
2858 | } | |
2859 | } | |
2860 | } | |
2861 | ||
2862 | /* | |
2863 | * Now that updates are safely completed, we can perform | |
2864 | * deletes. First delete the reflogs of any references that | |
2865 | * will be deleted, since (in the unexpected event of an | |
2866 | * error) leaving a reference without a reflog is less bad | |
2867 | * than leaving a reflog without a reference (the latter is a | |
2868 | * mildly invalid repository state): | |
2869 | */ | |
2870 | for (i = 0; i < transaction->nr; i++) { | |
2871 | struct ref_update *update = transaction->updates[i]; | |
2872 | if (update->flags & REF_DELETING && | |
2873 | !(update->flags & REF_LOG_ONLY) && | |
2874 | !(update->flags & REF_IS_PRUNING)) { | |
2875 | strbuf_reset(&sb); | |
2876 | files_reflog_path(refs, &sb, update->refname); | |
2877 | if (!unlink_or_warn(sb.buf)) | |
2878 | try_remove_empty_parents(refs, update->refname, | |
2879 | REMOVE_EMPTY_PARENTS_REFLOG); | |
2880 | } | |
2881 | } | |
2882 | ||
2883 | /* | |
2884 | * Perform deletes now that updates are safely completed. | |
2885 | * | |
2886 | * First delete any packed versions of the references, while | |
2887 | * retaining the packed-refs lock: | |
2888 | */ | |
2889 | if (packed_transaction) { | |
2890 | ret = ref_transaction_commit(packed_transaction, err); | |
2891 | ref_transaction_free(packed_transaction); | |
2892 | packed_transaction = NULL; | |
2893 | backend_data->packed_transaction = NULL; | |
2894 | if (ret) | |
2895 | goto cleanup; | |
2896 | } | |
2897 | ||
2898 | /* Now delete the loose versions of the references: */ | |
2899 | for (i = 0; i < transaction->nr; i++) { | |
2900 | struct ref_update *update = transaction->updates[i]; | |
2901 | struct ref_lock *lock = update->backend_data; | |
2902 | ||
2903 | if (update->flags & REF_DELETING && | |
2904 | !(update->flags & REF_LOG_ONLY)) { | |
2905 | update->flags |= REF_DELETED_RMDIR; | |
2906 | if (!(update->type & REF_ISPACKED) || | |
2907 | update->type & REF_ISSYMREF) { | |
2908 | /* It is a loose reference. */ | |
2909 | strbuf_reset(&sb); | |
2910 | files_ref_path(refs, &sb, lock->ref_name); | |
2911 | if (unlink_or_msg(sb.buf, err)) { | |
2912 | ret = TRANSACTION_GENERIC_ERROR; | |
2913 | goto cleanup; | |
2914 | } | |
2915 | } | |
2916 | } | |
2917 | } | |
2918 | ||
2919 | clear_loose_ref_cache(refs); | |
2920 | ||
2921 | cleanup: | |
2922 | files_transaction_cleanup(refs, transaction); | |
2923 | ||
2924 | for (i = 0; i < transaction->nr; i++) { | |
2925 | struct ref_update *update = transaction->updates[i]; | |
2926 | ||
2927 | if (update->flags & REF_DELETED_RMDIR) { | |
2928 | /* | |
2929 | * The reference was deleted. Delete any | |
2930 | * empty parent directories. (Note that this | |
2931 | * can only work because we have already | |
2932 | * removed the lockfile.) | |
2933 | */ | |
2934 | try_remove_empty_parents(refs, update->refname, | |
2935 | REMOVE_EMPTY_PARENTS_REF); | |
2936 | } | |
2937 | } | |
2938 | ||
2939 | strbuf_release(&sb); | |
2940 | return ret; | |
2941 | } | |
2942 | ||
2943 | static int files_transaction_abort(struct ref_store *ref_store, | |
2944 | struct ref_transaction *transaction, | |
2945 | struct strbuf *err UNUSED) | |
2946 | { | |
2947 | struct files_ref_store *refs = | |
2948 | files_downcast(ref_store, 0, "ref_transaction_abort"); | |
2949 | ||
2950 | files_transaction_cleanup(refs, transaction); | |
2951 | return 0; | |
2952 | } | |
2953 | ||
2954 | static int ref_present(const char *refname, | |
2955 | const struct object_id *oid UNUSED, | |
2956 | int flags UNUSED, | |
2957 | void *cb_data) | |
2958 | { | |
2959 | struct string_list *affected_refnames = cb_data; | |
2960 | ||
2961 | return string_list_has_string(affected_refnames, refname); | |
2962 | } | |
2963 | ||
2964 | static int files_initial_transaction_commit(struct ref_store *ref_store, | |
2965 | struct ref_transaction *transaction, | |
2966 | struct strbuf *err) | |
2967 | { | |
2968 | struct files_ref_store *refs = | |
2969 | files_downcast(ref_store, REF_STORE_WRITE, | |
2970 | "initial_ref_transaction_commit"); | |
2971 | size_t i; | |
2972 | int ret = 0; | |
2973 | struct string_list affected_refnames = STRING_LIST_INIT_NODUP; | |
2974 | struct ref_transaction *packed_transaction = NULL; | |
2975 | ||
2976 | assert(err); | |
2977 | ||
2978 | if (transaction->state != REF_TRANSACTION_OPEN) | |
2979 | BUG("commit called for transaction that is not open"); | |
2980 | ||
2981 | /* Fail if a refname appears more than once in the transaction: */ | |
2982 | for (i = 0; i < transaction->nr; i++) | |
2983 | string_list_append(&affected_refnames, | |
2984 | transaction->updates[i]->refname); | |
2985 | string_list_sort(&affected_refnames); | |
2986 | if (ref_update_reject_duplicates(&affected_refnames, err)) { | |
2987 | ret = TRANSACTION_GENERIC_ERROR; | |
2988 | goto cleanup; | |
2989 | } | |
2990 | ||
2991 | /* | |
2992 | * It's really undefined to call this function in an active | |
2993 | * repository or when there are existing references: we are | |
2994 | * only locking and changing packed-refs, so (1) any | |
2995 | * simultaneous processes might try to change a reference at | |
2996 | * the same time we do, and (2) any existing loose versions of | |
2997 | * the references that we are setting would have precedence | |
2998 | * over our values. But some remote helpers create the remote | |
2999 | * "HEAD" and "master" branches before calling this function, | |
3000 | * so here we really only check that none of the references | |
3001 | * that we are creating already exists. | |
3002 | */ | |
3003 | if (refs_for_each_rawref(&refs->base, ref_present, | |
3004 | &affected_refnames)) | |
3005 | BUG("initial ref transaction called with existing refs"); | |
3006 | ||
3007 | packed_transaction = ref_store_transaction_begin(refs->packed_ref_store, err); | |
3008 | if (!packed_transaction) { | |
3009 | ret = TRANSACTION_GENERIC_ERROR; | |
3010 | goto cleanup; | |
3011 | } | |
3012 | ||
3013 | for (i = 0; i < transaction->nr; i++) { | |
3014 | struct ref_update *update = transaction->updates[i]; | |
3015 | ||
3016 | if ((update->flags & REF_HAVE_OLD) && | |
3017 | !is_null_oid(&update->old_oid)) | |
3018 | BUG("initial ref transaction with old_sha1 set"); | |
3019 | if (refs_verify_refname_available(&refs->base, update->refname, | |
3020 | &affected_refnames, NULL, | |
3021 | err)) { | |
3022 | ret = TRANSACTION_NAME_CONFLICT; | |
3023 | goto cleanup; | |
3024 | } | |
3025 | ||
3026 | /* | |
3027 | * Add a reference creation for this reference to the | |
3028 | * packed-refs transaction: | |
3029 | */ | |
3030 | ref_transaction_add_update(packed_transaction, update->refname, | |
3031 | update->flags & ~REF_HAVE_OLD, | |
3032 | &update->new_oid, &update->old_oid, | |
3033 | NULL); | |
3034 | } | |
3035 | ||
3036 | if (packed_refs_lock(refs->packed_ref_store, 0, err)) { | |
3037 | ret = TRANSACTION_GENERIC_ERROR; | |
3038 | goto cleanup; | |
3039 | } | |
3040 | ||
3041 | if (initial_ref_transaction_commit(packed_transaction, err)) { | |
3042 | ret = TRANSACTION_GENERIC_ERROR; | |
3043 | } | |
3044 | ||
3045 | packed_refs_unlock(refs->packed_ref_store); | |
3046 | cleanup: | |
3047 | if (packed_transaction) | |
3048 | ref_transaction_free(packed_transaction); | |
3049 | transaction->state = REF_TRANSACTION_CLOSED; | |
3050 | string_list_clear(&affected_refnames, 0); | |
3051 | return ret; | |
3052 | } | |
3053 | ||
3054 | struct expire_reflog_cb { | |
3055 | reflog_expiry_should_prune_fn *should_prune_fn; | |
3056 | void *policy_cb; | |
3057 | FILE *newlog; | |
3058 | struct object_id last_kept_oid; | |
3059 | unsigned int rewrite:1, | |
3060 | dry_run:1; | |
3061 | }; | |
3062 | ||
3063 | static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid, | |
3064 | const char *email, timestamp_t timestamp, int tz, | |
3065 | const char *message, void *cb_data) | |
3066 | { | |
3067 | struct expire_reflog_cb *cb = cb_data; | |
3068 | reflog_expiry_should_prune_fn *fn = cb->should_prune_fn; | |
3069 | ||
3070 | if (cb->rewrite) | |
3071 | ooid = &cb->last_kept_oid; | |
3072 | ||
3073 | if (fn(ooid, noid, email, timestamp, tz, message, cb->policy_cb)) | |
3074 | return 0; | |
3075 | ||
3076 | if (cb->dry_run) | |
3077 | return 0; /* --dry-run */ | |
3078 | ||
3079 | fprintf(cb->newlog, "%s %s %s %"PRItime" %+05d\t%s", oid_to_hex(ooid), | |
3080 | oid_to_hex(noid), email, timestamp, tz, message); | |
3081 | oidcpy(&cb->last_kept_oid, noid); | |
3082 | ||
3083 | return 0; | |
3084 | } | |
3085 | ||
3086 | static int files_reflog_expire(struct ref_store *ref_store, | |
3087 | const char *refname, | |
3088 | unsigned int expire_flags, | |
3089 | reflog_expiry_prepare_fn prepare_fn, | |
3090 | reflog_expiry_should_prune_fn should_prune_fn, | |
3091 | reflog_expiry_cleanup_fn cleanup_fn, | |
3092 | void *policy_cb_data) | |
3093 | { | |
3094 | struct files_ref_store *refs = | |
3095 | files_downcast(ref_store, REF_STORE_WRITE, "reflog_expire"); | |
3096 | struct lock_file reflog_lock = LOCK_INIT; | |
3097 | struct expire_reflog_cb cb; | |
3098 | struct ref_lock *lock; | |
3099 | struct strbuf log_file_sb = STRBUF_INIT; | |
3100 | char *log_file; | |
3101 | int status = 0; | |
3102 | struct strbuf err = STRBUF_INIT; | |
3103 | const struct object_id *oid; | |
3104 | ||
3105 | memset(&cb, 0, sizeof(cb)); | |
3106 | cb.rewrite = !!(expire_flags & EXPIRE_REFLOGS_REWRITE); | |
3107 | cb.dry_run = !!(expire_flags & EXPIRE_REFLOGS_DRY_RUN); | |
3108 | cb.policy_cb = policy_cb_data; | |
3109 | cb.should_prune_fn = should_prune_fn; | |
3110 | ||
3111 | /* | |
3112 | * The reflog file is locked by holding the lock on the | |
3113 | * reference itself, plus we might need to update the | |
3114 | * reference if --updateref was specified: | |
3115 | */ | |
3116 | lock = lock_ref_oid_basic(refs, refname, &err); | |
3117 | if (!lock) { | |
3118 | error("cannot lock ref '%s': %s", refname, err.buf); | |
3119 | strbuf_release(&err); | |
3120 | return -1; | |
3121 | } | |
3122 | oid = &lock->old_oid; | |
3123 | ||
3124 | /* | |
3125 | * When refs are deleted, their reflog is deleted before the | |
3126 | * ref itself is deleted. This is because there is no separate | |
3127 | * lock for reflog; instead we take a lock on the ref with | |
3128 | * lock_ref_oid_basic(). | |
3129 | * | |
3130 | * If a race happens and the reflog doesn't exist after we've | |
3131 | * acquired the lock that's OK. We've got nothing more to do; | |
3132 | * We were asked to delete the reflog, but someone else | |
3133 | * deleted it! The caller doesn't care that we deleted it, | |
3134 | * just that it is deleted. So we can return successfully. | |
3135 | */ | |
3136 | if (!refs_reflog_exists(ref_store, refname)) { | |
3137 | unlock_ref(lock); | |
3138 | return 0; | |
3139 | } | |
3140 | ||
3141 | files_reflog_path(refs, &log_file_sb, refname); | |
3142 | log_file = strbuf_detach(&log_file_sb, NULL); | |
3143 | if (!cb.dry_run) { | |
3144 | /* | |
3145 | * Even though holding $GIT_DIR/logs/$reflog.lock has | |
3146 | * no locking implications, we use the lock_file | |
3147 | * machinery here anyway because it does a lot of the | |
3148 | * work we need, including cleaning up if the program | |
3149 | * exits unexpectedly. | |
3150 | */ | |
3151 | if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) { | |
3152 | struct strbuf err = STRBUF_INIT; | |
3153 | unable_to_lock_message(log_file, errno, &err); | |
3154 | error("%s", err.buf); | |
3155 | strbuf_release(&err); | |
3156 | goto failure; | |
3157 | } | |
3158 | cb.newlog = fdopen_lock_file(&reflog_lock, "w"); | |
3159 | if (!cb.newlog) { | |
3160 | error("cannot fdopen %s (%s)", | |
3161 | get_lock_file_path(&reflog_lock), strerror(errno)); | |
3162 | goto failure; | |
3163 | } | |
3164 | } | |
3165 | ||
3166 | (*prepare_fn)(refname, oid, cb.policy_cb); | |
3167 | refs_for_each_reflog_ent(ref_store, refname, expire_reflog_ent, &cb); | |
3168 | (*cleanup_fn)(cb.policy_cb); | |
3169 | ||
3170 | if (!cb.dry_run) { | |
3171 | /* | |
3172 | * It doesn't make sense to adjust a reference pointed | |
3173 | * to by a symbolic ref based on expiring entries in | |
3174 | * the symbolic reference's reflog. Nor can we update | |
3175 | * a reference if there are no remaining reflog | |
3176 | * entries. | |
3177 | */ | |
3178 | int update = 0; | |
3179 | ||
3180 | if ((expire_flags & EXPIRE_REFLOGS_UPDATE_REF) && | |
3181 | !is_null_oid(&cb.last_kept_oid)) { | |
3182 | int type; | |
3183 | const char *ref; | |
3184 | ||
3185 | ref = refs_resolve_ref_unsafe(&refs->base, refname, | |
3186 | RESOLVE_REF_NO_RECURSE, | |
3187 | NULL, &type); | |
3188 | update = !!(ref && !(type & REF_ISSYMREF)); | |
3189 | } | |
3190 | ||
3191 | if (close_lock_file_gently(&reflog_lock)) { | |
3192 | status |= error("couldn't write %s: %s", log_file, | |
3193 | strerror(errno)); | |
3194 | rollback_lock_file(&reflog_lock); | |
3195 | } else if (update && | |
3196 | (write_in_full(get_lock_file_fd(&lock->lk), | |
3197 | oid_to_hex(&cb.last_kept_oid), the_hash_algo->hexsz) < 0 || | |
3198 | write_str_in_full(get_lock_file_fd(&lock->lk), "\n") < 0 || | |
3199 | close_ref_gently(lock) < 0)) { | |
3200 | status |= error("couldn't write %s", | |
3201 | get_lock_file_path(&lock->lk)); | |
3202 | rollback_lock_file(&reflog_lock); | |
3203 | } else if (commit_lock_file(&reflog_lock)) { | |
3204 | status |= error("unable to write reflog '%s' (%s)", | |
3205 | log_file, strerror(errno)); | |
3206 | } else if (update && commit_ref(lock)) { | |
3207 | status |= error("couldn't set %s", lock->ref_name); | |
3208 | } | |
3209 | } | |
3210 | free(log_file); | |
3211 | unlock_ref(lock); | |
3212 | return status; | |
3213 | ||
3214 | failure: | |
3215 | rollback_lock_file(&reflog_lock); | |
3216 | free(log_file); | |
3217 | unlock_ref(lock); | |
3218 | return -1; | |
3219 | } | |
3220 | ||
3221 | static int files_init_db(struct ref_store *ref_store, | |
3222 | int flags, | |
3223 | struct strbuf *err UNUSED) | |
3224 | { | |
3225 | struct files_ref_store *refs = | |
3226 | files_downcast(ref_store, REF_STORE_WRITE, "init_db"); | |
3227 | struct strbuf sb = STRBUF_INIT; | |
3228 | ||
3229 | /* | |
3230 | * We need to create a "refs" dir in any case so that older versions of | |
3231 | * Git can tell that this is a repository. This serves two main purposes: | |
3232 | * | |
3233 | * - Clients will know to stop walking the parent-directory chain when | |
3234 | * detecting the Git repository. Otherwise they may end up detecting | |
3235 | * a Git repository in a parent directory instead. | |
3236 | * | |
3237 | * - Instead of failing to detect a repository with unknown reference | |
3238 | * format altogether, old clients will print an error saying that | |
3239 | * they do not understand the reference format extension. | |
3240 | */ | |
3241 | strbuf_addf(&sb, "%s/refs", ref_store->gitdir); | |
3242 | safe_create_dir(sb.buf, 1); | |
3243 | adjust_shared_perm(sb.buf); | |
3244 | ||
3245 | /* | |
3246 | * There is no need to create directories for common refs when creating | |
3247 | * a worktree ref store. | |
3248 | */ | |
3249 | if (!(flags & REFS_INIT_DB_IS_WORKTREE)) { | |
3250 | /* | |
3251 | * Create .git/refs/{heads,tags} | |
3252 | */ | |
3253 | strbuf_reset(&sb); | |
3254 | files_ref_path(refs, &sb, "refs/heads"); | |
3255 | safe_create_dir(sb.buf, 1); | |
3256 | ||
3257 | strbuf_reset(&sb); | |
3258 | files_ref_path(refs, &sb, "refs/tags"); | |
3259 | safe_create_dir(sb.buf, 1); | |
3260 | } | |
3261 | ||
3262 | strbuf_release(&sb); | |
3263 | return 0; | |
3264 | } | |
3265 | ||
3266 | struct ref_storage_be refs_be_files = { | |
3267 | .name = "files", | |
3268 | .init = files_ref_store_create, | |
3269 | .init_db = files_init_db, | |
3270 | .transaction_prepare = files_transaction_prepare, | |
3271 | .transaction_finish = files_transaction_finish, | |
3272 | .transaction_abort = files_transaction_abort, | |
3273 | .initial_transaction_commit = files_initial_transaction_commit, | |
3274 | ||
3275 | .pack_refs = files_pack_refs, | |
3276 | .create_symref = files_create_symref, | |
3277 | .rename_ref = files_rename_ref, | |
3278 | .copy_ref = files_copy_ref, | |
3279 | ||
3280 | .iterator_begin = files_ref_iterator_begin, | |
3281 | .read_raw_ref = files_read_raw_ref, | |
3282 | .read_symbolic_ref = files_read_symbolic_ref, | |
3283 | ||
3284 | .reflog_iterator_begin = files_reflog_iterator_begin, | |
3285 | .for_each_reflog_ent = files_for_each_reflog_ent, | |
3286 | .for_each_reflog_ent_reverse = files_for_each_reflog_ent_reverse, | |
3287 | .reflog_exists = files_reflog_exists, | |
3288 | .create_reflog = files_create_reflog, | |
3289 | .delete_reflog = files_delete_reflog, | |
3290 | .reflog_expire = files_reflog_expire | |
3291 | }; |