refs: tidy up and adjust visibility of the `ref_update` flags
[git/git.git] / refs / files-backend.c
CommitLineData
7bd9bcf3 1#include "../cache.h"
b2141fc1 2#include "../config.h"
7bd9bcf3
MH
3#include "../refs.h"
4#include "refs-internal.h"
958f9646 5#include "ref-cache.h"
67be7c5a 6#include "packed-backend.h"
3bc581b9 7#include "../iterator.h"
2880d16f 8#include "../dir-iterator.h"
7bd9bcf3
MH
9#include "../lockfile.h"
10#include "../object.h"
11#include "../dir.h"
12
5ac95fee
MH
13/*
14 * This backend uses the following flags in `ref_update::flags` for
15 * internal bookkeeping purposes. Their numerical values must not
16 * conflict with REF_NODEREF, REF_FORCE_CREATE_REFLOG, REF_HAVE_NEW,
17 * REF_HAVE_OLD, or REF_ISPRUNING, which are also stored in
18 * `ref_update::flags`.
19 */
20
21/*
22 * Used as a flag in ref_update::flags when a loose ref is being
23 * pruned. This flag must only be used when REF_NODEREF is set.
24 */
25#define REF_ISPRUNING (1 << 4)
26
27/*
28 * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken
29 * refs (i.e., because the reference is about to be deleted anyway).
30 */
31#define REF_DELETING (1 << 5)
32
33/*
34 * Used as a flag in ref_update::flags when the lockfile needs to be
35 * committed.
36 */
37#define REF_NEEDS_COMMIT (1 << 6)
38
39/*
40 * Used as a flag in ref_update::flags when we want to log a ref
41 * update but not actually perform it. This is used when a symbolic
42 * ref update is split up.
43 */
44#define REF_LOG_ONLY (1 << 7)
45
46/*
47 * Used as a flag in ref_update::flags when the ref_update was via an
48 * update to HEAD.
49 */
50#define REF_UPDATE_VIA_HEAD (1 << 8)
51
52/*
53 * Used as a flag in ref_update::flags when the loose reference has
54 * been deleted.
55 */
56#define REF_DELETED_LOOSE (1 << 9)
57
7bd9bcf3
MH
58struct ref_lock {
59 char *ref_name;
ee4d8e45 60 struct lock_file lk;
7bd9bcf3
MH
61 struct object_id old_oid;
62};
63
7bd9bcf3
MH
64/*
65 * Future: need to be in "struct repository"
66 * when doing a full libification.
67 */
00eebe35
MH
68struct files_ref_store {
69 struct ref_store base;
9e7ec634 70 unsigned int store_flags;
32c597e7 71
f57f37e2
NTND
72 char *gitdir;
73 char *gitcommondir;
33dfb9f3 74
7c22bc8a 75 struct ref_cache *loose;
55c6bc37 76
e0cc8ac8 77 struct ref_store *packed_ref_store;
00eebe35 78};
7bd9bcf3 79
65a0a8e5 80static void clear_loose_ref_cache(struct files_ref_store *refs)
7bd9bcf3
MH
81{
82 if (refs->loose) {
7c22bc8a 83 free_ref_cache(refs->loose);
7bd9bcf3
MH
84 refs->loose = NULL;
85 }
86}
87
a2d5156c
JK
88/*
89 * Create a new submodule ref cache and add it to the internal
90 * set of caches.
91 */
9e7ec634
NTND
92static struct ref_store *files_ref_store_create(const char *gitdir,
93 unsigned int flags)
7bd9bcf3 94{
00eebe35
MH
95 struct files_ref_store *refs = xcalloc(1, sizeof(*refs));
96 struct ref_store *ref_store = (struct ref_store *)refs;
f57f37e2 97 struct strbuf sb = STRBUF_INIT;
7bd9bcf3 98
fbfd0a29 99 base_ref_store_init(ref_store, &refs_be_files);
9e7ec634 100 refs->store_flags = flags;
7bd9bcf3 101
f57f37e2
NTND
102 refs->gitdir = xstrdup(gitdir);
103 get_common_dir_noenv(&sb, gitdir);
104 refs->gitcommondir = strbuf_detach(&sb, NULL);
105 strbuf_addf(&sb, "%s/packed-refs", refs->gitcommondir);
e0d48397
MH
106 refs->packed_ref_store = packed_ref_store_create(sb.buf, flags);
107 strbuf_release(&sb);
7bd9bcf3 108
00eebe35 109 return ref_store;
a2d5156c 110}
7bd9bcf3 111
32c597e7 112/*
9e7ec634
NTND
113 * Die if refs is not the main ref store. caller is used in any
114 * necessary error messages.
32c597e7
MH
115 */
116static void files_assert_main_repository(struct files_ref_store *refs,
117 const char *caller)
118{
9e7ec634
NTND
119 if (refs->store_flags & REF_STORE_MAIN)
120 return;
121
122 die("BUG: operation %s only allowed for main ref store", caller);
32c597e7
MH
123}
124
a2d5156c 125/*
00eebe35 126 * Downcast ref_store to files_ref_store. Die if ref_store is not a
9e7ec634
NTND
127 * files_ref_store. required_flags is compared with ref_store's
128 * store_flags to ensure the ref_store has all required capabilities.
129 * "caller" is used in any necessary error messages.
a2d5156c 130 */
9e7ec634
NTND
131static struct files_ref_store *files_downcast(struct ref_store *ref_store,
132 unsigned int required_flags,
133 const char *caller)
a2d5156c 134{
32c597e7
MH
135 struct files_ref_store *refs;
136
00eebe35
MH
137 if (ref_store->be != &refs_be_files)
138 die("BUG: ref_store is type \"%s\" not \"files\" in %s",
139 ref_store->be->name, caller);
2eed2780 140
32c597e7
MH
141 refs = (struct files_ref_store *)ref_store;
142
9e7ec634
NTND
143 if ((refs->store_flags & required_flags) != required_flags)
144 die("BUG: operation %s requires abilities 0x%x, but only have 0x%x",
145 caller, required_flags, refs->store_flags);
2eed2780 146
32c597e7 147 return refs;
7bd9bcf3
MH
148}
149
802de3da
NTND
150static void files_reflog_path(struct files_ref_store *refs,
151 struct strbuf *sb,
152 const char *refname)
153{
f57f37e2
NTND
154 switch (ref_type(refname)) {
155 case REF_TYPE_PER_WORKTREE:
156 case REF_TYPE_PSEUDOREF:
157 strbuf_addf(sb, "%s/logs/%s", refs->gitdir, refname);
158 break;
159 case REF_TYPE_NORMAL:
160 strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir, refname);
161 break;
162 default:
163 die("BUG: unknown ref type %d of ref %s",
164 ref_type(refname), refname);
165 }
802de3da
NTND
166}
167
19e02f4f
NTND
168static void files_ref_path(struct files_ref_store *refs,
169 struct strbuf *sb,
170 const char *refname)
171{
f57f37e2
NTND
172 switch (ref_type(refname)) {
173 case REF_TYPE_PER_WORKTREE:
174 case REF_TYPE_PSEUDOREF:
175 strbuf_addf(sb, "%s/%s", refs->gitdir, refname);
176 break;
177 case REF_TYPE_NORMAL:
178 strbuf_addf(sb, "%s/%s", refs->gitcommondir, refname);
179 break;
180 default:
181 die("BUG: unknown ref type %d of ref %s",
182 ref_type(refname), refname);
183 }
19e02f4f
NTND
184}
185
7bd9bcf3
MH
186/*
187 * Read the loose references from the namespace dirname into dir
188 * (without recursing). dirname must end with '/'. dir must be the
189 * directory entry corresponding to dirname.
190 */
df308759
MH
191static void loose_fill_ref_dir(struct ref_store *ref_store,
192 struct ref_dir *dir, const char *dirname)
7bd9bcf3 193{
df308759
MH
194 struct files_ref_store *refs =
195 files_downcast(ref_store, REF_STORE_READ, "fill_ref_dir");
7bd9bcf3
MH
196 DIR *d;
197 struct dirent *de;
198 int dirnamelen = strlen(dirname);
199 struct strbuf refname;
200 struct strbuf path = STRBUF_INIT;
201 size_t path_baselen;
202
19e02f4f 203 files_ref_path(refs, &path, dirname);
7bd9bcf3
MH
204 path_baselen = path.len;
205
206 d = opendir(path.buf);
207 if (!d) {
208 strbuf_release(&path);
209 return;
210 }
211
212 strbuf_init(&refname, dirnamelen + 257);
213 strbuf_add(&refname, dirname, dirnamelen);
214
215 while ((de = readdir(d)) != NULL) {
4417df8c 216 struct object_id oid;
7bd9bcf3
MH
217 struct stat st;
218 int flag;
219
220 if (de->d_name[0] == '.')
221 continue;
222 if (ends_with(de->d_name, ".lock"))
223 continue;
224 strbuf_addstr(&refname, de->d_name);
225 strbuf_addstr(&path, de->d_name);
226 if (stat(path.buf, &st) < 0) {
227 ; /* silently ignore */
228 } else if (S_ISDIR(st.st_mode)) {
229 strbuf_addch(&refname, '/');
230 add_entry_to_dir(dir,
e00d1a4f 231 create_dir_entry(dir->cache, refname.buf,
7bd9bcf3
MH
232 refname.len, 1));
233 } else {
7d2df051 234 if (!refs_resolve_ref_unsafe(&refs->base,
3c0cb0cb
MH
235 refname.buf,
236 RESOLVE_REF_READING,
49e61479 237 &oid, &flag)) {
4417df8c 238 oidclr(&oid);
7bd9bcf3 239 flag |= REF_ISBROKEN;
4417df8c 240 } else if (is_null_oid(&oid)) {
7bd9bcf3
MH
241 /*
242 * It is so astronomically unlikely
243 * that NULL_SHA1 is the SHA-1 of an
244 * actual object that we consider its
245 * appearance in a loose reference
246 * file to be repo corruption
247 * (probably due to a software bug).
248 */
249 flag |= REF_ISBROKEN;
250 }
251
252 if (check_refname_format(refname.buf,
253 REFNAME_ALLOW_ONELEVEL)) {
254 if (!refname_is_safe(refname.buf))
255 die("loose refname is dangerous: %s", refname.buf);
4417df8c 256 oidclr(&oid);
7bd9bcf3
MH
257 flag |= REF_BAD_NAME | REF_ISBROKEN;
258 }
259 add_entry_to_dir(dir,
c1da06c6 260 create_ref_entry(refname.buf, &oid, flag));
7bd9bcf3
MH
261 }
262 strbuf_setlen(&refname, dirnamelen);
263 strbuf_setlen(&path, path_baselen);
264 }
265 strbuf_release(&refname);
266 strbuf_release(&path);
267 closedir(d);
e3bf2989
MH
268
269 /*
270 * Manually add refs/bisect, which, being per-worktree, might
271 * not appear in the directory listing for refs/ in the main
272 * repo.
273 */
274 if (!strcmp(dirname, "refs/")) {
275 int pos = search_ref_dir(dir, "refs/bisect/", 12);
276
277 if (pos < 0) {
278 struct ref_entry *child_entry = create_dir_entry(
279 dir->cache, "refs/bisect/", 12, 1);
280 add_entry_to_dir(dir, child_entry);
281 }
282 }
7bd9bcf3
MH
283}
284
a714b19c 285static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs)
7bd9bcf3
MH
286{
287 if (!refs->loose) {
288 /*
289 * Mark the top-level directory complete because we
290 * are about to read the only subdirectory that can
291 * hold references:
292 */
df308759 293 refs->loose = create_ref_cache(&refs->base, loose_fill_ref_dir);
7c22bc8a
MH
294
295 /* We're going to fill the top level ourselves: */
296 refs->loose->root->flag &= ~REF_INCOMPLETE;
297
7bd9bcf3 298 /*
7c22bc8a
MH
299 * Add an incomplete entry for "refs/" (to be filled
300 * lazily):
7bd9bcf3 301 */
7c22bc8a 302 add_entry_to_dir(get_ref_dir(refs->loose->root),
e00d1a4f 303 create_dir_entry(refs->loose, "refs/", 5, 1));
7bd9bcf3 304 }
a714b19c 305 return refs->loose;
7bd9bcf3
MH
306}
307
e1e33b72 308static int files_read_raw_ref(struct ref_store *ref_store,
99afe91a 309 const char *refname, struct object_id *oid,
e1e33b72 310 struct strbuf *referent, unsigned int *type)
7bd9bcf3 311{
4308651c 312 struct files_ref_store *refs =
9e7ec634 313 files_downcast(ref_store, REF_STORE_READ, "read_raw_ref");
42a38cf7
MH
314 struct strbuf sb_contents = STRBUF_INIT;
315 struct strbuf sb_path = STRBUF_INIT;
7048653a
DT
316 const char *path;
317 const char *buf;
99afe91a 318 const char *p;
7048653a
DT
319 struct stat st;
320 int fd;
42a38cf7
MH
321 int ret = -1;
322 int save_errno;
e8c42cb9 323 int remaining_retries = 3;
7bd9bcf3 324
fa96ea1b 325 *type = 0;
42a38cf7 326 strbuf_reset(&sb_path);
34c7ad8f 327
19e02f4f 328 files_ref_path(refs, &sb_path, refname);
34c7ad8f 329
42a38cf7 330 path = sb_path.buf;
7bd9bcf3 331
7048653a
DT
332stat_ref:
333 /*
334 * We might have to loop back here to avoid a race
335 * condition: first we lstat() the file, then we try
336 * to read it as a link or as a file. But if somebody
337 * changes the type of the file (file <-> directory
338 * <-> symlink) between the lstat() and reading, then
339 * we don't want to report that as an error but rather
340 * try again starting with the lstat().
e8c42cb9
JK
341 *
342 * We'll keep a count of the retries, though, just to avoid
343 * any confusing situation sending us into an infinite loop.
7048653a 344 */
7bd9bcf3 345
e8c42cb9
JK
346 if (remaining_retries-- <= 0)
347 goto out;
348
7048653a
DT
349 if (lstat(path, &st) < 0) {
350 if (errno != ENOENT)
42a38cf7 351 goto out;
e0cc8ac8 352 if (refs_read_raw_ref(refs->packed_ref_store, refname,
99afe91a 353 oid, referent, type)) {
7048653a 354 errno = ENOENT;
42a38cf7 355 goto out;
7bd9bcf3 356 }
42a38cf7
MH
357 ret = 0;
358 goto out;
7bd9bcf3 359 }
7bd9bcf3 360
7048653a
DT
361 /* Follow "normalized" - ie "refs/.." symlinks by hand */
362 if (S_ISLNK(st.st_mode)) {
42a38cf7
MH
363 strbuf_reset(&sb_contents);
364 if (strbuf_readlink(&sb_contents, path, 0) < 0) {
7048653a 365 if (errno == ENOENT || errno == EINVAL)
7bd9bcf3
MH
366 /* inconsistent with lstat; retry */
367 goto stat_ref;
368 else
42a38cf7 369 goto out;
7bd9bcf3 370 }
42a38cf7
MH
371 if (starts_with(sb_contents.buf, "refs/") &&
372 !check_refname_format(sb_contents.buf, 0)) {
92b38093 373 strbuf_swap(&sb_contents, referent);
3a0b6b9a 374 *type |= REF_ISSYMREF;
42a38cf7
MH
375 ret = 0;
376 goto out;
7bd9bcf3 377 }
3f7bd767
JK
378 /*
379 * It doesn't look like a refname; fall through to just
380 * treating it like a non-symlink, and reading whatever it
381 * points to.
382 */
7048653a 383 }
7bd9bcf3 384
7048653a
DT
385 /* Is it a directory? */
386 if (S_ISDIR(st.st_mode)) {
e167a567
MH
387 /*
388 * Even though there is a directory where the loose
389 * ref is supposed to be, there could still be a
390 * packed ref:
391 */
e0cc8ac8 392 if (refs_read_raw_ref(refs->packed_ref_store, refname,
99afe91a 393 oid, referent, type)) {
e167a567
MH
394 errno = EISDIR;
395 goto out;
396 }
397 ret = 0;
42a38cf7 398 goto out;
7048653a
DT
399 }
400
401 /*
402 * Anything else, just open it and try to use it as
403 * a ref
404 */
405 fd = open(path, O_RDONLY);
406 if (fd < 0) {
3f7bd767 407 if (errno == ENOENT && !S_ISLNK(st.st_mode))
7048653a
DT
408 /* inconsistent with lstat; retry */
409 goto stat_ref;
410 else
42a38cf7 411 goto out;
7048653a 412 }
42a38cf7
MH
413 strbuf_reset(&sb_contents);
414 if (strbuf_read(&sb_contents, fd, 256) < 0) {
7048653a
DT
415 int save_errno = errno;
416 close(fd);
417 errno = save_errno;
42a38cf7 418 goto out;
7048653a
DT
419 }
420 close(fd);
42a38cf7
MH
421 strbuf_rtrim(&sb_contents);
422 buf = sb_contents.buf;
7048653a
DT
423 if (starts_with(buf, "ref:")) {
424 buf += 4;
7bd9bcf3
MH
425 while (isspace(*buf))
426 buf++;
7048653a 427
92b38093
MH
428 strbuf_reset(referent);
429 strbuf_addstr(referent, buf);
3a0b6b9a 430 *type |= REF_ISSYMREF;
42a38cf7
MH
431 ret = 0;
432 goto out;
7bd9bcf3 433 }
7bd9bcf3 434
7048653a
DT
435 /*
436 * Please note that FETCH_HEAD has additional
437 * data after the sha.
438 */
99afe91a 439 if (parse_oid_hex(buf, oid, &p) ||
440 (*p != '\0' && !isspace(*p))) {
3a0b6b9a 441 *type |= REF_ISBROKEN;
7048653a 442 errno = EINVAL;
42a38cf7 443 goto out;
7048653a
DT
444 }
445
42a38cf7 446 ret = 0;
7bd9bcf3 447
42a38cf7
MH
448out:
449 save_errno = errno;
7bd9bcf3
MH
450 strbuf_release(&sb_path);
451 strbuf_release(&sb_contents);
42a38cf7 452 errno = save_errno;
7bd9bcf3
MH
453 return ret;
454}
455
8415d247
MH
456static void unlock_ref(struct ref_lock *lock)
457{
ee4d8e45 458 rollback_lock_file(&lock->lk);
8415d247 459 free(lock->ref_name);
8415d247
MH
460 free(lock);
461}
462
92b1551b
MH
463/*
464 * Lock refname, without following symrefs, and set *lock_p to point
465 * at a newly-allocated lock object. Fill in lock->old_oid, referent,
466 * and type similarly to read_raw_ref().
467 *
468 * The caller must verify that refname is a "safe" reference name (in
469 * the sense of refname_is_safe()) before calling this function.
470 *
471 * If the reference doesn't already exist, verify that refname doesn't
472 * have a D/F conflict with any existing references. extras and skip
524a9fdb 473 * are passed to refs_verify_refname_available() for this check.
92b1551b
MH
474 *
475 * If mustexist is not set and the reference is not found or is
476 * broken, lock the reference anyway but clear sha1.
477 *
478 * Return 0 on success. On failure, write an error message to err and
479 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.
480 *
481 * Implementation note: This function is basically
482 *
483 * lock reference
484 * read_raw_ref()
485 *
486 * but it includes a lot more code to
487 * - Deal with possible races with other processes
524a9fdb 488 * - Avoid calling refs_verify_refname_available() when it can be
92b1551b
MH
489 * avoided, namely if we were successfully able to read the ref
490 * - Generate informative error messages in the case of failure
491 */
f7b0a987
MH
492static int lock_raw_ref(struct files_ref_store *refs,
493 const char *refname, int mustexist,
92b1551b
MH
494 const struct string_list *extras,
495 const struct string_list *skip,
496 struct ref_lock **lock_p,
497 struct strbuf *referent,
498 unsigned int *type,
499 struct strbuf *err)
500{
501 struct ref_lock *lock;
502 struct strbuf ref_file = STRBUF_INIT;
503 int attempts_remaining = 3;
504 int ret = TRANSACTION_GENERIC_ERROR;
505
506 assert(err);
32c597e7 507 files_assert_main_repository(refs, "lock_raw_ref");
f7b0a987 508
92b1551b
MH
509 *type = 0;
510
511 /* First lock the file so it can't change out from under us. */
512
513 *lock_p = lock = xcalloc(1, sizeof(*lock));
514
515 lock->ref_name = xstrdup(refname);
19e02f4f 516 files_ref_path(refs, &ref_file, refname);
92b1551b
MH
517
518retry:
519 switch (safe_create_leading_directories(ref_file.buf)) {
520 case SCLD_OK:
521 break; /* success */
522 case SCLD_EXISTS:
523 /*
524 * Suppose refname is "refs/foo/bar". We just failed
525 * to create the containing directory, "refs/foo",
526 * because there was a non-directory in the way. This
527 * indicates a D/F conflict, probably because of
528 * another reference such as "refs/foo". There is no
529 * reason to expect this error to be transitory.
530 */
7d2df051
NTND
531 if (refs_verify_refname_available(&refs->base, refname,
532 extras, skip, err)) {
92b1551b
MH
533 if (mustexist) {
534 /*
535 * To the user the relevant error is
536 * that the "mustexist" reference is
537 * missing:
538 */
539 strbuf_reset(err);
540 strbuf_addf(err, "unable to resolve reference '%s'",
541 refname);
542 } else {
543 /*
544 * The error message set by
524a9fdb
MH
545 * refs_verify_refname_available() is
546 * OK.
92b1551b
MH
547 */
548 ret = TRANSACTION_NAME_CONFLICT;
549 }
550 } else {
551 /*
552 * The file that is in the way isn't a loose
553 * reference. Report it as a low-level
554 * failure.
555 */
556 strbuf_addf(err, "unable to create lock file %s.lock; "
557 "non-directory in the way",
558 ref_file.buf);
559 }
560 goto error_return;
561 case SCLD_VANISHED:
562 /* Maybe another process was tidying up. Try again. */
563 if (--attempts_remaining > 0)
564 goto retry;
565 /* fall through */
566 default:
567 strbuf_addf(err, "unable to create directory for %s",
568 ref_file.buf);
569 goto error_return;
570 }
571
4ff0f01c 572 if (hold_lock_file_for_update_timeout(
ee4d8e45 573 &lock->lk, ref_file.buf, LOCK_NO_DEREF,
4ff0f01c 574 get_files_ref_lock_timeout_ms()) < 0) {
92b1551b
MH
575 if (errno == ENOENT && --attempts_remaining > 0) {
576 /*
577 * Maybe somebody just deleted one of the
578 * directories leading to ref_file. Try
579 * again:
580 */
581 goto retry;
582 } else {
583 unable_to_lock_message(ref_file.buf, errno, err);
584 goto error_return;
585 }
586 }
587
588 /*
589 * Now we hold the lock and can read the reference without
590 * fear that its value will change.
591 */
592
f7b0a987 593 if (files_read_raw_ref(&refs->base, refname,
99afe91a 594 &lock->old_oid, referent, type)) {
92b1551b
MH
595 if (errno == ENOENT) {
596 if (mustexist) {
597 /* Garden variety missing reference. */
598 strbuf_addf(err, "unable to resolve reference '%s'",
599 refname);
600 goto error_return;
601 } else {
602 /*
603 * Reference is missing, but that's OK. We
604 * know that there is not a conflict with
605 * another loose reference because
606 * (supposing that we are trying to lock
607 * reference "refs/foo/bar"):
608 *
609 * - We were successfully able to create
610 * the lockfile refs/foo/bar.lock, so we
611 * know there cannot be a loose reference
612 * named "refs/foo".
613 *
614 * - We got ENOENT and not EISDIR, so we
615 * know that there cannot be a loose
616 * reference named "refs/foo/bar/baz".
617 */
618 }
619 } else if (errno == EISDIR) {
620 /*
621 * There is a directory in the way. It might have
622 * contained references that have been deleted. If
623 * we don't require that the reference already
624 * exists, try to remove the directory so that it
625 * doesn't cause trouble when we want to rename the
626 * lockfile into place later.
627 */
628 if (mustexist) {
629 /* Garden variety missing reference. */
630 strbuf_addf(err, "unable to resolve reference '%s'",
631 refname);
632 goto error_return;
633 } else if (remove_dir_recursively(&ref_file,
634 REMOVE_DIR_EMPTY_ONLY)) {
b05855b5
MH
635 if (refs_verify_refname_available(
636 &refs->base, refname,
637 extras, skip, err)) {
92b1551b
MH
638 /*
639 * The error message set by
640 * verify_refname_available() is OK.
641 */
642 ret = TRANSACTION_NAME_CONFLICT;
643 goto error_return;
644 } else {
645 /*
646 * We can't delete the directory,
647 * but we also don't know of any
648 * references that it should
649 * contain.
650 */
651 strbuf_addf(err, "there is a non-empty directory '%s' "
652 "blocking reference '%s'",
653 ref_file.buf, refname);
654 goto error_return;
655 }
656 }
657 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) {
658 strbuf_addf(err, "unable to resolve reference '%s': "
659 "reference broken", refname);
660 goto error_return;
661 } else {
662 strbuf_addf(err, "unable to resolve reference '%s': %s",
663 refname, strerror(errno));
664 goto error_return;
665 }
666
667 /*
668 * If the ref did not exist and we are creating it,
8ec617c8
MH
669 * make sure there is no existing packed ref that
670 * conflicts with refname:
92b1551b 671 */
524a9fdb 672 if (refs_verify_refname_available(
8ec617c8 673 refs->packed_ref_store, refname,
524a9fdb 674 extras, skip, err))
92b1551b 675 goto error_return;
92b1551b
MH
676 }
677
678 ret = 0;
679 goto out;
680
681error_return:
682 unlock_ref(lock);
683 *lock_p = NULL;
684
685out:
686 strbuf_release(&ref_file);
687 return ret;
688}
689
3bc581b9
MH
690struct files_ref_iterator {
691 struct ref_iterator base;
692
3bc581b9
MH
693 struct ref_iterator *iter0;
694 unsigned int flags;
695};
7bd9bcf3 696
3bc581b9
MH
697static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)
698{
699 struct files_ref_iterator *iter =
700 (struct files_ref_iterator *)ref_iterator;
701 int ok;
7bd9bcf3 702
3bc581b9 703 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
0c09ec07
DT
704 if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&
705 ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)
706 continue;
707
3bc581b9
MH
708 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
709 !ref_resolves_to_object(iter->iter0->refname,
710 iter->iter0->oid,
711 iter->iter0->flags))
712 continue;
713
714 iter->base.refname = iter->iter0->refname;
715 iter->base.oid = iter->iter0->oid;
716 iter->base.flags = iter->iter0->flags;
717 return ITER_OK;
7bd9bcf3
MH
718 }
719
3bc581b9
MH
720 iter->iter0 = NULL;
721 if (ref_iterator_abort(ref_iterator) != ITER_DONE)
722 ok = ITER_ERROR;
723
724 return ok;
7bd9bcf3
MH
725}
726
3bc581b9
MH
727static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,
728 struct object_id *peeled)
7bd9bcf3 729{
3bc581b9
MH
730 struct files_ref_iterator *iter =
731 (struct files_ref_iterator *)ref_iterator;
93770590 732
3bc581b9
MH
733 return ref_iterator_peel(iter->iter0, peeled);
734}
735
736static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)
737{
738 struct files_ref_iterator *iter =
739 (struct files_ref_iterator *)ref_iterator;
740 int ok = ITER_DONE;
741
742 if (iter->iter0)
743 ok = ref_iterator_abort(iter->iter0);
744
3bc581b9
MH
745 base_ref_iterator_free(ref_iterator);
746 return ok;
747}
748
749static struct ref_iterator_vtable files_ref_iterator_vtable = {
750 files_ref_iterator_advance,
751 files_ref_iterator_peel,
752 files_ref_iterator_abort
753};
754
1a769003 755static struct ref_iterator *files_ref_iterator_begin(
37b6f6d5 756 struct ref_store *ref_store,
3bc581b9
MH
757 const char *prefix, unsigned int flags)
758{
9e7ec634 759 struct files_ref_store *refs;
8738a8a4 760 struct ref_iterator *loose_iter, *packed_iter, *overlay_iter;
3bc581b9
MH
761 struct files_ref_iterator *iter;
762 struct ref_iterator *ref_iterator;
0a0865b8 763 unsigned int required_flags = REF_STORE_READ;
3bc581b9 764
0a0865b8
MH
765 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN))
766 required_flags |= REF_STORE_ODB;
3bc581b9 767
0a0865b8 768 refs = files_downcast(ref_store, required_flags, "ref_iterator_begin");
9e7ec634 769
3bc581b9
MH
770 /*
771 * We must make sure that all loose refs are read before
772 * accessing the packed-refs file; this avoids a race
773 * condition if loose refs are migrated to the packed-refs
774 * file by a simultaneous process, but our in-memory view is
775 * from before the migration. We ensure this as follows:
059ae35a
MH
776 * First, we call start the loose refs iteration with its
777 * `prime_ref` argument set to true. This causes the loose
778 * references in the subtree to be pre-read into the cache.
779 * (If they've already been read, that's OK; we only need to
780 * guarantee that they're read before the packed refs, not
781 * *how much* before.) After that, we call
38b86e81
MH
782 * packed_ref_iterator_begin(), which internally checks
783 * whether the packed-ref cache is up to date with what is on
784 * disk, and re-reads it if not.
3bc581b9
MH
785 */
786
059ae35a
MH
787 loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs),
788 prefix, 1);
3bc581b9 789
38b86e81
MH
790 /*
791 * The packed-refs file might contain broken references, for
792 * example an old version of a reference that points at an
793 * object that has since been garbage-collected. This is OK as
794 * long as there is a corresponding loose reference that
795 * overrides it, and we don't want to emit an error message in
796 * this case. So ask the packed_ref_store for all of its
797 * references, and (if needed) do our own check for broken
798 * ones in files_ref_iterator_advance(), after we have merged
799 * the packed and loose references.
800 */
e0cc8ac8
MH
801 packed_iter = refs_ref_iterator_begin(
802 refs->packed_ref_store, prefix, 0,
38b86e81 803 DO_FOR_EACH_INCLUDE_BROKEN);
3bc581b9 804
8738a8a4
MH
805 overlay_iter = overlay_ref_iterator_begin(loose_iter, packed_iter);
806
807 iter = xcalloc(1, sizeof(*iter));
808 ref_iterator = &iter->base;
809 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable,
810 overlay_iter->ordered);
811 iter->iter0 = overlay_iter;
3bc581b9
MH
812 iter->flags = flags;
813
814 return ref_iterator;
7bd9bcf3
MH
815}
816
7bd9bcf3 817/*
4f01e508 818 * Verify that the reference locked by lock has the value old_oid
819 * (unless it is NULL). Fail if the reference doesn't exist and
820 * mustexist is set. Return 0 on success. On error, write an error
821 * message to err, set errno, and return a negative value.
7bd9bcf3 822 */
2f40e954 823static int verify_lock(struct ref_store *ref_store, struct ref_lock *lock,
4f01e508 824 const struct object_id *old_oid, int mustexist,
7bd9bcf3
MH
825 struct strbuf *err)
826{
827 assert(err);
828
2f40e954
NTND
829 if (refs_read_ref_full(ref_store, lock->ref_name,
830 mustexist ? RESOLVE_REF_READING : 0,
34c290a6 831 &lock->old_oid, NULL)) {
4f01e508 832 if (old_oid) {
6294dcb4 833 int save_errno = errno;
0568c8e9 834 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);
6294dcb4
JK
835 errno = save_errno;
836 return -1;
837 } else {
c368dde9 838 oidclr(&lock->old_oid);
6294dcb4
JK
839 return 0;
840 }
7bd9bcf3 841 }
4f01e508 842 if (old_oid && oidcmp(&lock->old_oid, old_oid)) {
0568c8e9 843 strbuf_addf(err, "ref '%s' is at %s but expected %s",
7bd9bcf3 844 lock->ref_name,
c368dde9 845 oid_to_hex(&lock->old_oid),
4f01e508 846 oid_to_hex(old_oid));
7bd9bcf3
MH
847 errno = EBUSY;
848 return -1;
849 }
850 return 0;
851}
852
853static int remove_empty_directories(struct strbuf *path)
854{
855 /*
856 * we want to create a file but there is a directory there;
857 * if that is an empty directory (or a directory that contains
858 * only empty directories), remove them.
859 */
860 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);
861}
862
3b5d3c98
MH
863static int create_reflock(const char *path, void *cb)
864{
865 struct lock_file *lk = cb;
866
4ff0f01c
MH
867 return hold_lock_file_for_update_timeout(
868 lk, path, LOCK_NO_DEREF,
869 get_files_ref_lock_timeout_ms()) < 0 ? -1 : 0;
3b5d3c98
MH
870}
871
7bd9bcf3
MH
872/*
873 * Locks a ref returning the lock on success and NULL on failure.
874 * On failure errno is set to something meaningful.
875 */
4f01e508 876static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
877 const char *refname,
878 const struct object_id *old_oid,
879 const struct string_list *extras,
880 const struct string_list *skip,
881 unsigned int flags, int *type,
882 struct strbuf *err)
7bd9bcf3
MH
883{
884 struct strbuf ref_file = STRBUF_INIT;
7bd9bcf3
MH
885 struct ref_lock *lock;
886 int last_errno = 0;
4f01e508 887 int mustexist = (old_oid && !is_null_oid(old_oid));
7a418f3a 888 int resolve_flags = RESOLVE_REF_NO_RECURSE;
7a418f3a 889 int resolved;
7bd9bcf3 890
4f01e508 891 files_assert_main_repository(refs, "lock_ref_oid_basic");
7bd9bcf3
MH
892 assert(err);
893
894 lock = xcalloc(1, sizeof(struct ref_lock));
895
896 if (mustexist)
897 resolve_flags |= RESOLVE_REF_READING;
2859dcd4 898 if (flags & REF_DELETING)
7bd9bcf3 899 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
7bd9bcf3 900
19e02f4f 901 files_ref_path(refs, &ref_file, refname);
2f40e954
NTND
902 resolved = !!refs_resolve_ref_unsafe(&refs->base,
903 refname, resolve_flags,
49e61479 904 &lock->old_oid, type);
7a418f3a 905 if (!resolved && errno == EISDIR) {
7bd9bcf3
MH
906 /*
907 * we are trying to lock foo but we used to
908 * have foo/bar which now does not exist;
909 * it is normal for the empty directory 'foo'
910 * to remain.
911 */
7a418f3a 912 if (remove_empty_directories(&ref_file)) {
7bd9bcf3 913 last_errno = errno;
b05855b5
MH
914 if (!refs_verify_refname_available(
915 &refs->base,
916 refname, extras, skip, err))
7bd9bcf3 917 strbuf_addf(err, "there are still refs under '%s'",
7a418f3a 918 refname);
7bd9bcf3
MH
919 goto error_return;
920 }
2f40e954
NTND
921 resolved = !!refs_resolve_ref_unsafe(&refs->base,
922 refname, resolve_flags,
49e61479 923 &lock->old_oid, type);
7bd9bcf3 924 }
7a418f3a 925 if (!resolved) {
7bd9bcf3
MH
926 last_errno = errno;
927 if (last_errno != ENOTDIR ||
b05855b5
MH
928 !refs_verify_refname_available(&refs->base, refname,
929 extras, skip, err))
0568c8e9 930 strbuf_addf(err, "unable to resolve reference '%s': %s",
7a418f3a 931 refname, strerror(last_errno));
7bd9bcf3
MH
932
933 goto error_return;
934 }
2859dcd4 935
7bd9bcf3
MH
936 /*
937 * If the ref did not exist and we are creating it, make sure
938 * there is no existing packed ref whose name begins with our
939 * refname, nor a packed ref whose name is a proper prefix of
940 * our refname.
941 */
942 if (is_null_oid(&lock->old_oid) &&
8ec617c8 943 refs_verify_refname_available(refs->packed_ref_store, refname,
524a9fdb 944 extras, skip, err)) {
7bd9bcf3
MH
945 last_errno = ENOTDIR;
946 goto error_return;
947 }
948
7bd9bcf3 949 lock->ref_name = xstrdup(refname);
7bd9bcf3 950
ee4d8e45 951 if (raceproof_create_file(ref_file.buf, create_reflock, &lock->lk)) {
7bd9bcf3 952 last_errno = errno;
3b5d3c98 953 unable_to_lock_message(ref_file.buf, errno, err);
7bd9bcf3
MH
954 goto error_return;
955 }
956
4f01e508 957 if (verify_lock(&refs->base, lock, old_oid, mustexist, err)) {
7bd9bcf3
MH
958 last_errno = errno;
959 goto error_return;
960 }
961 goto out;
962
963 error_return:
964 unlock_ref(lock);
965 lock = NULL;
966
967 out:
968 strbuf_release(&ref_file);
7bd9bcf3
MH
969 errno = last_errno;
970 return lock;
971}
972
7bd9bcf3
MH
973struct ref_to_prune {
974 struct ref_to_prune *next;
49e99588 975 struct object_id oid;
7bd9bcf3
MH
976 char name[FLEX_ARRAY];
977};
978
a8f0db2d
MH
979enum {
980 REMOVE_EMPTY_PARENTS_REF = 0x01,
981 REMOVE_EMPTY_PARENTS_REFLOG = 0x02
982};
983
7bd9bcf3 984/*
a8f0db2d
MH
985 * Remove empty parent directories associated with the specified
986 * reference and/or its reflog, but spare [logs/]refs/ and immediate
987 * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or
988 * REMOVE_EMPTY_PARENTS_REFLOG.
7bd9bcf3 989 */
802de3da
NTND
990static void try_remove_empty_parents(struct files_ref_store *refs,
991 const char *refname,
992 unsigned int flags)
7bd9bcf3 993{
8bdaecb4 994 struct strbuf buf = STRBUF_INIT;
e9dcc305 995 struct strbuf sb = STRBUF_INIT;
7bd9bcf3
MH
996 char *p, *q;
997 int i;
8bdaecb4
MH
998
999 strbuf_addstr(&buf, refname);
1000 p = buf.buf;
7bd9bcf3
MH
1001 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
1002 while (*p && *p != '/')
1003 p++;
1004 /* tolerate duplicate slashes; see check_refname_format() */
1005 while (*p == '/')
1006 p++;
1007 }
8bdaecb4 1008 q = buf.buf + buf.len;
a8f0db2d 1009 while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {
7bd9bcf3
MH
1010 while (q > p && *q != '/')
1011 q--;
1012 while (q > p && *(q-1) == '/')
1013 q--;
1014 if (q == p)
1015 break;
8bdaecb4 1016 strbuf_setlen(&buf, q - buf.buf);
e9dcc305
NTND
1017
1018 strbuf_reset(&sb);
19e02f4f 1019 files_ref_path(refs, &sb, buf.buf);
e9dcc305 1020 if ((flags & REMOVE_EMPTY_PARENTS_REF) && rmdir(sb.buf))
a8f0db2d 1021 flags &= ~REMOVE_EMPTY_PARENTS_REF;
e9dcc305
NTND
1022
1023 strbuf_reset(&sb);
802de3da 1024 files_reflog_path(refs, &sb, buf.buf);
e9dcc305 1025 if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) && rmdir(sb.buf))
a8f0db2d 1026 flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;
7bd9bcf3 1027 }
8bdaecb4 1028 strbuf_release(&buf);
e9dcc305 1029 strbuf_release(&sb);
7bd9bcf3
MH
1030}
1031
1032/* make sure nobody touched the ref, and unlink */
2f40e954 1033static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r)
7bd9bcf3
MH
1034{
1035 struct ref_transaction *transaction;
1036 struct strbuf err = STRBUF_INIT;
b00f3cfa 1037 int ret = -1;
7bd9bcf3
MH
1038
1039 if (check_refname_format(r->name, 0))
1040 return;
1041
2f40e954 1042 transaction = ref_store_transaction_begin(&refs->base, &err);
b00f3cfa
MH
1043 if (!transaction)
1044 goto cleanup;
1045 ref_transaction_add_update(
1046 transaction, r->name,
1047 REF_NODEREF | REF_HAVE_NEW | REF_HAVE_OLD | REF_ISPRUNING,
1048 &null_oid, &r->oid, NULL);
1049 if (ref_transaction_commit(transaction, &err))
1050 goto cleanup;
1051
1052 ret = 0;
1053
1054cleanup:
1055 if (ret)
7bd9bcf3 1056 error("%s", err.buf);
7bd9bcf3 1057 strbuf_release(&err);
b00f3cfa
MH
1058 ref_transaction_free(transaction);
1059 return;
7bd9bcf3
MH
1060}
1061
22b09cdf
MH
1062/*
1063 * Prune the loose versions of the references in the linked list
1064 * `*refs_to_prune`, freeing the entries in the list as we go.
1065 */
1066static void prune_refs(struct files_ref_store *refs, struct ref_to_prune **refs_to_prune)
7bd9bcf3 1067{
22b09cdf
MH
1068 while (*refs_to_prune) {
1069 struct ref_to_prune *r = *refs_to_prune;
1070 *refs_to_prune = r->next;
2f40e954 1071 prune_ref(refs, r);
22b09cdf 1072 free(r);
7bd9bcf3
MH
1073 }
1074}
1075
531cc4a5
MH
1076/*
1077 * Return true if the specified reference should be packed.
1078 */
1079static int should_pack_ref(const char *refname,
1080 const struct object_id *oid, unsigned int ref_flags,
1081 unsigned int pack_flags)
1082{
1083 /* Do not pack per-worktree refs: */
1084 if (ref_type(refname) != REF_TYPE_NORMAL)
1085 return 0;
1086
1087 /* Do not pack non-tags unless PACK_REFS_ALL is set: */
1088 if (!(pack_flags & PACK_REFS_ALL) && !starts_with(refname, "refs/tags/"))
1089 return 0;
1090
1091 /* Do not pack symbolic refs: */
1092 if (ref_flags & REF_ISSYMREF)
1093 return 0;
1094
1095 /* Do not pack broken refs: */
1096 if (!ref_resolves_to_object(refname, oid, ref_flags))
1097 return 0;
1098
1099 return 1;
1100}
1101
8231527e 1102static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)
7bd9bcf3 1103{
00eebe35 1104 struct files_ref_store *refs =
9e7ec634
NTND
1105 files_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB,
1106 "pack_refs");
50c2d855 1107 struct ref_iterator *iter;
50c2d855
MH
1108 int ok;
1109 struct ref_to_prune *refs_to_prune = NULL;
3478983b 1110 struct strbuf err = STRBUF_INIT;
27d03d04
MH
1111 struct ref_transaction *transaction;
1112
1113 transaction = ref_store_transaction_begin(refs->packed_ref_store, &err);
1114 if (!transaction)
1115 return -1;
7bd9bcf3 1116
c8bed835 1117 packed_refs_lock(refs->packed_ref_store, LOCK_DIE_ON_ERROR, &err);
50c2d855
MH
1118
1119 iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), NULL, 0);
1120 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1121 /*
1122 * If the loose reference can be packed, add an entry
1123 * in the packed ref cache. If the reference should be
1124 * pruned, also add it to refs_to_prune.
1125 */
531cc4a5
MH
1126 if (!should_pack_ref(iter->refname, iter->oid, iter->flags,
1127 flags))
50c2d855
MH
1128 continue;
1129
1130 /*
27d03d04
MH
1131 * Add a reference creation for this reference to the
1132 * packed-refs transaction:
50c2d855 1133 */
27d03d04 1134 if (ref_transaction_update(transaction, iter->refname,
89f3bbdd 1135 iter->oid, NULL,
27d03d04
MH
1136 REF_NODEREF, NULL, &err))
1137 die("failure preparing to create packed reference %s: %s",
1138 iter->refname, err.buf);
50c2d855
MH
1139
1140 /* Schedule the loose reference for pruning if requested. */
1141 if ((flags & PACK_REFS_PRUNE)) {
1142 struct ref_to_prune *n;
1143 FLEX_ALLOC_STR(n, name, iter->refname);
49e99588 1144 oidcpy(&n->oid, iter->oid);
50c2d855
MH
1145 n->next = refs_to_prune;
1146 refs_to_prune = n;
1147 }
1148 }
1149 if (ok != ITER_DONE)
1150 die("error while iterating over references");
7bd9bcf3 1151
27d03d04
MH
1152 if (ref_transaction_commit(transaction, &err))
1153 die("unable to write new packed-refs: %s", err.buf);
1154
1155 ref_transaction_free(transaction);
1156
42c7f7ff 1157 packed_refs_unlock(refs->packed_ref_store);
7bd9bcf3 1158
22b09cdf 1159 prune_refs(refs, &refs_to_prune);
3478983b 1160 strbuf_release(&err);
7bd9bcf3
MH
1161 return 0;
1162}
1163
64da4199 1164static int files_delete_refs(struct ref_store *ref_store, const char *msg,
a27dcf89 1165 struct string_list *refnames, unsigned int flags)
7bd9bcf3 1166{
0a95ac5f 1167 struct files_ref_store *refs =
9e7ec634 1168 files_downcast(ref_store, REF_STORE_WRITE, "delete_refs");
7bd9bcf3
MH
1169 struct strbuf err = STRBUF_INIT;
1170 int i, result = 0;
1171
1172 if (!refnames->nr)
1173 return 0;
1174
e5cc7d7d
MH
1175 if (packed_refs_lock(refs->packed_ref_store, 0, &err))
1176 goto error;
7bd9bcf3 1177
2fb330ca 1178 if (refs_delete_refs(refs->packed_ref_store, msg, refnames, flags)) {
e5cc7d7d
MH
1179 packed_refs_unlock(refs->packed_ref_store);
1180 goto error;
7bd9bcf3
MH
1181 }
1182
e5cc7d7d
MH
1183 packed_refs_unlock(refs->packed_ref_store);
1184
7bd9bcf3
MH
1185 for (i = 0; i < refnames->nr; i++) {
1186 const char *refname = refnames->items[i].string;
1187
64da4199 1188 if (refs_delete_ref(&refs->base, msg, refname, NULL, flags))
7bd9bcf3
MH
1189 result |= error(_("could not remove reference %s"), refname);
1190 }
1191
7bd9bcf3
MH
1192 strbuf_release(&err);
1193 return result;
e5cc7d7d
MH
1194
1195error:
1196 /*
1197 * If we failed to rewrite the packed-refs file, then it is
1198 * unsafe to try to remove loose refs, because doing so might
1199 * expose an obsolete packed value for a reference that might
1200 * even point at an object that has been garbage collected.
1201 */
1202 if (refnames->nr == 1)
1203 error(_("could not delete reference %s: %s"),
1204 refnames->items[0].string, err.buf);
1205 else
1206 error(_("could not delete references: %s"), err.buf);
1207
1208 strbuf_release(&err);
1209 return -1;
7bd9bcf3
MH
1210}
1211
1212/*
1213 * People using contrib's git-new-workdir have .git/logs/refs ->
1214 * /some/other/path/.git/logs/refs, and that may live on another device.
1215 *
1216 * IOW, to avoid cross device rename errors, the temporary renamed log must
1217 * live into logs/refs.
1218 */
a5c1efd6 1219#define TMP_RENAMED_LOG "refs/.tmp-renamed-log"
7bd9bcf3 1220
e9dcc305
NTND
1221struct rename_cb {
1222 const char *tmp_renamed_log;
1223 int true_errno;
1224};
1225
1226static int rename_tmp_log_callback(const char *path, void *cb_data)
7bd9bcf3 1227{
e9dcc305 1228 struct rename_cb *cb = cb_data;
7bd9bcf3 1229
e9dcc305 1230 if (rename(cb->tmp_renamed_log, path)) {
6a7f3631
MH
1231 /*
1232 * rename(a, b) when b is an existing directory ought
1233 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.
1234 * Sheesh. Record the true errno for error reporting,
1235 * but report EISDIR to raceproof_create_file() so
1236 * that it knows to retry.
1237 */
e9dcc305 1238 cb->true_errno = errno;
6a7f3631
MH
1239 if (errno == ENOTDIR)
1240 errno = EISDIR;
1241 return -1;
1242 } else {
1243 return 0;
7bd9bcf3 1244 }
6a7f3631 1245}
7bd9bcf3 1246
802de3da 1247static int rename_tmp_log(struct files_ref_store *refs, const char *newrefname)
6a7f3631 1248{
e9dcc305
NTND
1249 struct strbuf path = STRBUF_INIT;
1250 struct strbuf tmp = STRBUF_INIT;
1251 struct rename_cb cb;
1252 int ret;
6a7f3631 1253
802de3da
NTND
1254 files_reflog_path(refs, &path, newrefname);
1255 files_reflog_path(refs, &tmp, TMP_RENAMED_LOG);
e9dcc305
NTND
1256 cb.tmp_renamed_log = tmp.buf;
1257 ret = raceproof_create_file(path.buf, rename_tmp_log_callback, &cb);
6a7f3631
MH
1258 if (ret) {
1259 if (errno == EISDIR)
e9dcc305 1260 error("directory not empty: %s", path.buf);
6a7f3631 1261 else
990c98d2 1262 error("unable to move logfile %s to %s: %s",
e9dcc305
NTND
1263 tmp.buf, path.buf,
1264 strerror(cb.true_errno));
7bd9bcf3 1265 }
6a7f3631 1266
e9dcc305
NTND
1267 strbuf_release(&path);
1268 strbuf_release(&tmp);
7bd9bcf3
MH
1269 return ret;
1270}
1271
7bd9bcf3 1272static int write_ref_to_lockfile(struct ref_lock *lock,
4417df8c 1273 const struct object_id *oid, struct strbuf *err);
f18a7892
MH
1274static int commit_ref_update(struct files_ref_store *refs,
1275 struct ref_lock *lock,
4417df8c 1276 const struct object_id *oid, const char *logmsg,
5d9b2de4 1277 struct strbuf *err);
7bd9bcf3 1278
52d59cc6 1279static int files_copy_or_rename_ref(struct ref_store *ref_store,
9b6b40d9 1280 const char *oldrefname, const char *newrefname,
52d59cc6 1281 const char *logmsg, int copy)
7bd9bcf3 1282{
9b6b40d9 1283 struct files_ref_store *refs =
9e7ec634 1284 files_downcast(ref_store, REF_STORE_WRITE, "rename_ref");
4417df8c 1285 struct object_id oid, orig_oid;
7bd9bcf3
MH
1286 int flag = 0, logmoved = 0;
1287 struct ref_lock *lock;
1288 struct stat loginfo;
e9dcc305
NTND
1289 struct strbuf sb_oldref = STRBUF_INIT;
1290 struct strbuf sb_newref = STRBUF_INIT;
1291 struct strbuf tmp_renamed_log = STRBUF_INIT;
1292 int log, ret;
7bd9bcf3
MH
1293 struct strbuf err = STRBUF_INIT;
1294
802de3da
NTND
1295 files_reflog_path(refs, &sb_oldref, oldrefname);
1296 files_reflog_path(refs, &sb_newref, newrefname);
1297 files_reflog_path(refs, &tmp_renamed_log, TMP_RENAMED_LOG);
e9dcc305
NTND
1298
1299 log = !lstat(sb_oldref.buf, &loginfo);
0a3f07d6
NTND
1300 if (log && S_ISLNK(loginfo.st_mode)) {
1301 ret = error("reflog for %s is a symlink", oldrefname);
1302 goto out;
1303 }
7bd9bcf3 1304
2f40e954
NTND
1305 if (!refs_resolve_ref_unsafe(&refs->base, oldrefname,
1306 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
49e61479 1307 &orig_oid, &flag)) {
0a3f07d6
NTND
1308 ret = error("refname %s not found", oldrefname);
1309 goto out;
1310 }
e711b1af 1311
0a3f07d6 1312 if (flag & REF_ISSYMREF) {
52d59cc6
SD
1313 if (copy)
1314 ret = error("refname %s is a symbolic ref, copying it is not supported",
1315 oldrefname);
1316 else
1317 ret = error("refname %s is a symbolic ref, renaming it is not supported",
1318 oldrefname);
0a3f07d6
NTND
1319 goto out;
1320 }
7d2df051 1321 if (!refs_rename_ref_available(&refs->base, oldrefname, newrefname)) {
0a3f07d6
NTND
1322 ret = 1;
1323 goto out;
1324 }
7bd9bcf3 1325
52d59cc6 1326 if (!copy && log && rename(sb_oldref.buf, tmp_renamed_log.buf)) {
a5c1efd6 1327 ret = error("unable to move logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",
0a3f07d6
NTND
1328 oldrefname, strerror(errno));
1329 goto out;
1330 }
7bd9bcf3 1331
52d59cc6
SD
1332 if (copy && log && copy_file(tmp_renamed_log.buf, sb_oldref.buf, 0644)) {
1333 ret = error("unable to copy logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",
1334 oldrefname, strerror(errno));
1335 goto out;
1336 }
1337
1338 if (!copy && refs_delete_ref(&refs->base, logmsg, oldrefname,
2616a5e5 1339 &orig_oid, REF_NODEREF)) {
7bd9bcf3
MH
1340 error("unable to delete old %s", oldrefname);
1341 goto rollback;
1342 }
1343
12fd3496 1344 /*
4417df8c 1345 * Since we are doing a shallow lookup, oid is not the
1346 * correct value to pass to delete_ref as old_oid. But that
1347 * doesn't matter, because an old_oid check wouldn't add to
12fd3496
DT
1348 * the safety anyway; we want to delete the reference whatever
1349 * its current value.
1350 */
52d59cc6 1351 if (!copy && !refs_read_ref_full(&refs->base, newrefname,
2f40e954 1352 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
34c290a6 1353 &oid, NULL) &&
2f40e954
NTND
1354 refs_delete_ref(&refs->base, NULL, newrefname,
1355 NULL, REF_NODEREF)) {
58364324 1356 if (errno == EISDIR) {
7bd9bcf3
MH
1357 struct strbuf path = STRBUF_INIT;
1358 int result;
1359
19e02f4f 1360 files_ref_path(refs, &path, newrefname);
7bd9bcf3
MH
1361 result = remove_empty_directories(&path);
1362 strbuf_release(&path);
1363
1364 if (result) {
1365 error("Directory not empty: %s", newrefname);
1366 goto rollback;
1367 }
1368 } else {
1369 error("unable to delete existing %s", newrefname);
1370 goto rollback;
1371 }
1372 }
1373
802de3da 1374 if (log && rename_tmp_log(refs, newrefname))
7bd9bcf3
MH
1375 goto rollback;
1376
1377 logmoved = log;
1378
4f01e508 1379 lock = lock_ref_oid_basic(refs, newrefname, NULL, NULL, NULL,
1380 REF_NODEREF, NULL, &err);
7bd9bcf3 1381 if (!lock) {
52d59cc6
SD
1382 if (copy)
1383 error("unable to copy '%s' to '%s': %s", oldrefname, newrefname, err.buf);
1384 else
1385 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);
7bd9bcf3
MH
1386 strbuf_release(&err);
1387 goto rollback;
1388 }
4417df8c 1389 oidcpy(&lock->old_oid, &orig_oid);
7bd9bcf3 1390
4417df8c 1391 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||
1392 commit_ref_update(refs, lock, &orig_oid, logmsg, &err)) {
7bd9bcf3
MH
1393 error("unable to write current sha1 into %s: %s", newrefname, err.buf);
1394 strbuf_release(&err);
1395 goto rollback;
1396 }
1397
0a3f07d6
NTND
1398 ret = 0;
1399 goto out;
7bd9bcf3
MH
1400
1401 rollback:
4f01e508 1402 lock = lock_ref_oid_basic(refs, oldrefname, NULL, NULL, NULL,
1403 REF_NODEREF, NULL, &err);
7bd9bcf3
MH
1404 if (!lock) {
1405 error("unable to lock %s for rollback: %s", oldrefname, err.buf);
1406 strbuf_release(&err);
1407 goto rollbacklog;
1408 }
1409
1410 flag = log_all_ref_updates;
341fb286 1411 log_all_ref_updates = LOG_REFS_NONE;
4417df8c 1412 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||
1413 commit_ref_update(refs, lock, &orig_oid, NULL, &err)) {
7bd9bcf3
MH
1414 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);
1415 strbuf_release(&err);
1416 }
1417 log_all_ref_updates = flag;
1418
1419 rollbacklog:
e9dcc305 1420 if (logmoved && rename(sb_newref.buf, sb_oldref.buf))
7bd9bcf3
MH
1421 error("unable to restore logfile %s from %s: %s",
1422 oldrefname, newrefname, strerror(errno));
1423 if (!logmoved && log &&
e9dcc305 1424 rename(tmp_renamed_log.buf, sb_oldref.buf))
a5c1efd6 1425 error("unable to restore logfile %s from logs/"TMP_RENAMED_LOG": %s",
7bd9bcf3 1426 oldrefname, strerror(errno));
0a3f07d6
NTND
1427 ret = 1;
1428 out:
e9dcc305
NTND
1429 strbuf_release(&sb_newref);
1430 strbuf_release(&sb_oldref);
1431 strbuf_release(&tmp_renamed_log);
1432
0a3f07d6 1433 return ret;
7bd9bcf3
MH
1434}
1435
52d59cc6
SD
1436static int files_rename_ref(struct ref_store *ref_store,
1437 const char *oldrefname, const char *newrefname,
1438 const char *logmsg)
1439{
1440 return files_copy_or_rename_ref(ref_store, oldrefname,
1441 newrefname, logmsg, 0);
1442}
1443
1444static int files_copy_ref(struct ref_store *ref_store,
1445 const char *oldrefname, const char *newrefname,
1446 const char *logmsg)
1447{
1448 return files_copy_or_rename_ref(ref_store, oldrefname,
1449 newrefname, logmsg, 1);
1450}
1451
83a3069a 1452static int close_ref_gently(struct ref_lock *lock)
7bd9bcf3 1453{
ee4d8e45 1454 if (close_lock_file_gently(&lock->lk))
7bd9bcf3
MH
1455 return -1;
1456 return 0;
1457}
1458
1459static int commit_ref(struct ref_lock *lock)
1460{
ee4d8e45 1461 char *path = get_locked_file_path(&lock->lk);
5387c0d8
MH
1462 struct stat st;
1463
1464 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {
1465 /*
1466 * There is a directory at the path we want to rename
1467 * the lockfile to. Hopefully it is empty; try to
1468 * delete it.
1469 */
1470 size_t len = strlen(path);
1471 struct strbuf sb_path = STRBUF_INIT;
1472
1473 strbuf_attach(&sb_path, path, len, len);
1474
1475 /*
1476 * If this fails, commit_lock_file() will also fail
1477 * and will report the problem.
1478 */
1479 remove_empty_directories(&sb_path);
1480 strbuf_release(&sb_path);
1481 } else {
1482 free(path);
1483 }
1484
ee4d8e45 1485 if (commit_lock_file(&lock->lk))
7bd9bcf3
MH
1486 return -1;
1487 return 0;
1488}
1489
1fb0c809
MH
1490static int open_or_create_logfile(const char *path, void *cb)
1491{
1492 int *fd = cb;
1493
1494 *fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666);
1495 return (*fd < 0) ? -1 : 0;
1496}
1497
7bd9bcf3 1498/*
4533e534
MH
1499 * Create a reflog for a ref. If force_create = 0, only create the
1500 * reflog for certain refs (those for which should_autocreate_reflog
1501 * returns non-zero). Otherwise, create it regardless of the reference
1502 * name. If the logfile already existed or was created, return 0 and
1503 * set *logfd to the file descriptor opened for appending to the file.
1504 * If no logfile exists and we decided not to create one, return 0 and
1505 * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and
1506 * return -1.
7bd9bcf3 1507 */
802de3da
NTND
1508static int log_ref_setup(struct files_ref_store *refs,
1509 const char *refname, int force_create,
4533e534 1510 int *logfd, struct strbuf *err)
7bd9bcf3 1511{
802de3da
NTND
1512 struct strbuf logfile_sb = STRBUF_INIT;
1513 char *logfile;
1514
1515 files_reflog_path(refs, &logfile_sb, refname);
1516 logfile = strbuf_detach(&logfile_sb, NULL);
7bd9bcf3 1517
7bd9bcf3 1518 if (force_create || should_autocreate_reflog(refname)) {
4533e534 1519 if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) {
1fb0c809
MH
1520 if (errno == ENOENT)
1521 strbuf_addf(err, "unable to create directory for '%s': "
4533e534 1522 "%s", logfile, strerror(errno));
1fb0c809
MH
1523 else if (errno == EISDIR)
1524 strbuf_addf(err, "there are still logs under '%s'",
4533e534 1525 logfile);
1fb0c809 1526 else
854bda6b 1527 strbuf_addf(err, "unable to append to '%s': %s",
4533e534 1528 logfile, strerror(errno));
7bd9bcf3 1529
4533e534 1530 goto error;
7bd9bcf3 1531 }
854bda6b 1532 } else {
4533e534 1533 *logfd = open(logfile, O_APPEND | O_WRONLY, 0666);
e404f459 1534 if (*logfd < 0) {
854bda6b
MH
1535 if (errno == ENOENT || errno == EISDIR) {
1536 /*
1537 * The logfile doesn't already exist,
1538 * but that is not an error; it only
1539 * means that we won't write log
1540 * entries to it.
1541 */
1542 ;
1543 } else {
1544 strbuf_addf(err, "unable to append to '%s': %s",
4533e534
MH
1545 logfile, strerror(errno));
1546 goto error;
854bda6b 1547 }
7bd9bcf3
MH
1548 }
1549 }
1550
e404f459 1551 if (*logfd >= 0)
4533e534 1552 adjust_shared_perm(logfile);
854bda6b 1553
4533e534 1554 free(logfile);
7bd9bcf3 1555 return 0;
7bd9bcf3 1556
4533e534
MH
1557error:
1558 free(logfile);
1559 return -1;
7bd9bcf3 1560}
7bd9bcf3 1561
e3688bd6
DT
1562static int files_create_reflog(struct ref_store *ref_store,
1563 const char *refname, int force_create,
1564 struct strbuf *err)
7bd9bcf3 1565{
802de3da 1566 struct files_ref_store *refs =
9e7ec634 1567 files_downcast(ref_store, REF_STORE_WRITE, "create_reflog");
e404f459 1568 int fd;
7bd9bcf3 1569
802de3da 1570 if (log_ref_setup(refs, refname, force_create, &fd, err))
4533e534
MH
1571 return -1;
1572
e404f459
MH
1573 if (fd >= 0)
1574 close(fd);
4533e534
MH
1575
1576 return 0;
7bd9bcf3
MH
1577}
1578
4417df8c 1579static int log_ref_write_fd(int fd, const struct object_id *old_oid,
1580 const struct object_id *new_oid,
7bd9bcf3
MH
1581 const char *committer, const char *msg)
1582{
1583 int msglen, written;
1584 unsigned maxlen, len;
1585 char *logrec;
1586
1587 msglen = msg ? strlen(msg) : 0;
1588 maxlen = strlen(committer) + msglen + 100;
1589 logrec = xmalloc(maxlen);
1590 len = xsnprintf(logrec, maxlen, "%s %s %s\n",
4417df8c 1591 oid_to_hex(old_oid),
1592 oid_to_hex(new_oid),
7bd9bcf3
MH
1593 committer);
1594 if (msglen)
1595 len += copy_reflog_msg(logrec + len - 1, msg) - 1;
1596
1597 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;
1598 free(logrec);
564bde9a 1599 if (written < 0)
7bd9bcf3
MH
1600 return -1;
1601
1602 return 0;
1603}
1604
802de3da 1605static int files_log_ref_write(struct files_ref_store *refs,
4417df8c 1606 const char *refname, const struct object_id *old_oid,
1607 const struct object_id *new_oid, const char *msg,
11f8457f 1608 int flags, struct strbuf *err)
7bd9bcf3 1609{
e404f459 1610 int logfd, result;
7bd9bcf3 1611
341fb286
CW
1612 if (log_all_ref_updates == LOG_REFS_UNSET)
1613 log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;
7bd9bcf3 1614
802de3da
NTND
1615 result = log_ref_setup(refs, refname,
1616 flags & REF_FORCE_CREATE_REFLOG,
4533e534 1617 &logfd, err);
7bd9bcf3
MH
1618
1619 if (result)
1620 return result;
1621
7bd9bcf3
MH
1622 if (logfd < 0)
1623 return 0;
4417df8c 1624 result = log_ref_write_fd(logfd, old_oid, new_oid,
7bd9bcf3
MH
1625 git_committer_info(0), msg);
1626 if (result) {
e9dcc305 1627 struct strbuf sb = STRBUF_INIT;
87b21e05
MH
1628 int save_errno = errno;
1629
802de3da 1630 files_reflog_path(refs, &sb, refname);
87b21e05 1631 strbuf_addf(err, "unable to append to '%s': %s",
e9dcc305
NTND
1632 sb.buf, strerror(save_errno));
1633 strbuf_release(&sb);
7bd9bcf3
MH
1634 close(logfd);
1635 return -1;
1636 }
1637 if (close(logfd)) {
e9dcc305 1638 struct strbuf sb = STRBUF_INIT;
87b21e05
MH
1639 int save_errno = errno;
1640
802de3da 1641 files_reflog_path(refs, &sb, refname);
87b21e05 1642 strbuf_addf(err, "unable to append to '%s': %s",
e9dcc305
NTND
1643 sb.buf, strerror(save_errno));
1644 strbuf_release(&sb);
7bd9bcf3
MH
1645 return -1;
1646 }
1647 return 0;
1648}
1649
7bd9bcf3
MH
1650/*
1651 * Write sha1 into the open lockfile, then close the lockfile. On
1652 * errors, rollback the lockfile, fill in *err and
1653 * return -1.
1654 */
1655static int write_ref_to_lockfile(struct ref_lock *lock,
4417df8c 1656 const struct object_id *oid, struct strbuf *err)
7bd9bcf3
MH
1657{
1658 static char term = '\n';
1659 struct object *o;
1660 int fd;
1661
c251c83d 1662 o = parse_object(oid);
7bd9bcf3
MH
1663 if (!o) {
1664 strbuf_addf(err,
0568c8e9 1665 "trying to write ref '%s' with nonexistent object %s",
4417df8c 1666 lock->ref_name, oid_to_hex(oid));
7bd9bcf3
MH
1667 unlock_ref(lock);
1668 return -1;
1669 }
1670 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1671 strbuf_addf(err,
0568c8e9 1672 "trying to write non-commit object %s to branch '%s'",
4417df8c 1673 oid_to_hex(oid), lock->ref_name);
7bd9bcf3
MH
1674 unlock_ref(lock);
1675 return -1;
1676 }
ee4d8e45 1677 fd = get_lock_file_fd(&lock->lk);
06f46f23
JK
1678 if (write_in_full(fd, oid_to_hex(oid), GIT_SHA1_HEXSZ) < 0 ||
1679 write_in_full(fd, &term, 1) < 0 ||
83a3069a 1680 close_ref_gently(lock) < 0) {
7bd9bcf3 1681 strbuf_addf(err,
ee4d8e45 1682 "couldn't write '%s'", get_lock_file_path(&lock->lk));
7bd9bcf3
MH
1683 unlock_ref(lock);
1684 return -1;
1685 }
1686 return 0;
1687}
1688
1689/*
1690 * Commit a change to a loose reference that has already been written
1691 * to the loose reference lockfile. Also update the reflogs if
1692 * necessary, using the specified lockmsg (which can be NULL).
1693 */
f18a7892
MH
1694static int commit_ref_update(struct files_ref_store *refs,
1695 struct ref_lock *lock,
4417df8c 1696 const struct object_id *oid, const char *logmsg,
5d9b2de4 1697 struct strbuf *err)
7bd9bcf3 1698{
32c597e7 1699 files_assert_main_repository(refs, "commit_ref_update");
00eebe35
MH
1700
1701 clear_loose_ref_cache(refs);
802de3da 1702 if (files_log_ref_write(refs, lock->ref_name,
4417df8c 1703 &lock->old_oid, oid,
81b1b6d4 1704 logmsg, 0, err)) {
7bd9bcf3 1705 char *old_msg = strbuf_detach(err, NULL);
0568c8e9 1706 strbuf_addf(err, "cannot update the ref '%s': %s",
7bd9bcf3
MH
1707 lock->ref_name, old_msg);
1708 free(old_msg);
1709 unlock_ref(lock);
1710 return -1;
1711 }
7a418f3a
MH
1712
1713 if (strcmp(lock->ref_name, "HEAD") != 0) {
7bd9bcf3
MH
1714 /*
1715 * Special hack: If a branch is updated directly and HEAD
1716 * points to it (may happen on the remote side of a push
1717 * for example) then logically the HEAD reflog should be
1718 * updated too.
1719 * A generic solution implies reverse symref information,
1720 * but finding all symrefs pointing to the given branch
1721 * would be rather costly for this rare event (the direct
1722 * update of a branch) to be worth it. So let's cheat and
1723 * check with HEAD only which should cover 99% of all usage
1724 * scenarios (even 100% of the default ones).
1725 */
7bd9bcf3
MH
1726 int head_flag;
1727 const char *head_ref;
7a418f3a 1728
2f40e954
NTND
1729 head_ref = refs_resolve_ref_unsafe(&refs->base, "HEAD",
1730 RESOLVE_REF_READING,
e691b027 1731 NULL, &head_flag);
7bd9bcf3
MH
1732 if (head_ref && (head_flag & REF_ISSYMREF) &&
1733 !strcmp(head_ref, lock->ref_name)) {
1734 struct strbuf log_err = STRBUF_INIT;
802de3da 1735 if (files_log_ref_write(refs, "HEAD",
4417df8c 1736 &lock->old_oid, oid,
802de3da 1737 logmsg, 0, &log_err)) {
7bd9bcf3
MH
1738 error("%s", log_err.buf);
1739 strbuf_release(&log_err);
1740 }
1741 }
1742 }
7a418f3a 1743
7bd9bcf3 1744 if (commit_ref(lock)) {
0568c8e9 1745 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
7bd9bcf3
MH
1746 unlock_ref(lock);
1747 return -1;
1748 }
1749
1750 unlock_ref(lock);
1751 return 0;
1752}
1753
370e5ad6 1754static int create_ref_symlink(struct ref_lock *lock, const char *target)
7bd9bcf3 1755{
370e5ad6 1756 int ret = -1;
7bd9bcf3 1757#ifndef NO_SYMLINK_HEAD
ee4d8e45 1758 char *ref_path = get_locked_file_path(&lock->lk);
370e5ad6
JK
1759 unlink(ref_path);
1760 ret = symlink(target, ref_path);
1761 free(ref_path);
1762
1763 if (ret)
7bd9bcf3 1764 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
7bd9bcf3 1765#endif
370e5ad6
JK
1766 return ret;
1767}
7bd9bcf3 1768
802de3da
NTND
1769static void update_symref_reflog(struct files_ref_store *refs,
1770 struct ref_lock *lock, const char *refname,
370e5ad6
JK
1771 const char *target, const char *logmsg)
1772{
1773 struct strbuf err = STRBUF_INIT;
4417df8c 1774 struct object_id new_oid;
2f40e954
NTND
1775 if (logmsg &&
1776 !refs_read_ref_full(&refs->base, target,
34c290a6 1777 RESOLVE_REF_READING, &new_oid, NULL) &&
4417df8c 1778 files_log_ref_write(refs, refname, &lock->old_oid,
1779 &new_oid, logmsg, 0, &err)) {
7bd9bcf3
MH
1780 error("%s", err.buf);
1781 strbuf_release(&err);
1782 }
370e5ad6 1783}
7bd9bcf3 1784
802de3da
NTND
1785static int create_symref_locked(struct files_ref_store *refs,
1786 struct ref_lock *lock, const char *refname,
370e5ad6
JK
1787 const char *target, const char *logmsg)
1788{
1789 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {
802de3da 1790 update_symref_reflog(refs, lock, refname, target, logmsg);
370e5ad6
JK
1791 return 0;
1792 }
1793
ee4d8e45 1794 if (!fdopen_lock_file(&lock->lk, "w"))
370e5ad6 1795 return error("unable to fdopen %s: %s",
ee4d8e45 1796 lock->lk.tempfile->filename.buf, strerror(errno));
370e5ad6 1797
802de3da 1798 update_symref_reflog(refs, lock, refname, target, logmsg);
396da8f7 1799
370e5ad6 1800 /* no error check; commit_ref will check ferror */
ee4d8e45 1801 fprintf(lock->lk.tempfile->fp, "ref: %s\n", target);
370e5ad6
JK
1802 if (commit_ref(lock) < 0)
1803 return error("unable to write symref for %s: %s", refname,
1804 strerror(errno));
7bd9bcf3
MH
1805 return 0;
1806}
1807
284689ba
MH
1808static int files_create_symref(struct ref_store *ref_store,
1809 const char *refname, const char *target,
1810 const char *logmsg)
370e5ad6 1811{
7eb27cdf 1812 struct files_ref_store *refs =
9e7ec634 1813 files_downcast(ref_store, REF_STORE_WRITE, "create_symref");
370e5ad6
JK
1814 struct strbuf err = STRBUF_INIT;
1815 struct ref_lock *lock;
1816 int ret;
1817
4f01e508 1818 lock = lock_ref_oid_basic(refs, refname, NULL,
1819 NULL, NULL, REF_NODEREF, NULL,
1820 &err);
370e5ad6
JK
1821 if (!lock) {
1822 error("%s", err.buf);
1823 strbuf_release(&err);
1824 return -1;
1825 }
1826
802de3da 1827 ret = create_symref_locked(refs, lock, refname, target, logmsg);
370e5ad6
JK
1828 unlock_ref(lock);
1829 return ret;
1830}
1831
e3688bd6
DT
1832static int files_reflog_exists(struct ref_store *ref_store,
1833 const char *refname)
7bd9bcf3 1834{
802de3da 1835 struct files_ref_store *refs =
9e7ec634 1836 files_downcast(ref_store, REF_STORE_READ, "reflog_exists");
e9dcc305 1837 struct strbuf sb = STRBUF_INIT;
7bd9bcf3 1838 struct stat st;
e9dcc305 1839 int ret;
7bd9bcf3 1840
802de3da 1841 files_reflog_path(refs, &sb, refname);
e9dcc305
NTND
1842 ret = !lstat(sb.buf, &st) && S_ISREG(st.st_mode);
1843 strbuf_release(&sb);
1844 return ret;
7bd9bcf3
MH
1845}
1846
e3688bd6
DT
1847static int files_delete_reflog(struct ref_store *ref_store,
1848 const char *refname)
7bd9bcf3 1849{
802de3da 1850 struct files_ref_store *refs =
9e7ec634 1851 files_downcast(ref_store, REF_STORE_WRITE, "delete_reflog");
e9dcc305
NTND
1852 struct strbuf sb = STRBUF_INIT;
1853 int ret;
1854
802de3da 1855 files_reflog_path(refs, &sb, refname);
e9dcc305
NTND
1856 ret = remove_path(sb.buf);
1857 strbuf_release(&sb);
1858 return ret;
7bd9bcf3
MH
1859}
1860
1861static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
1862{
9461d272 1863 struct object_id ooid, noid;
7bd9bcf3 1864 char *email_end, *message;
dddbad72 1865 timestamp_t timestamp;
7bd9bcf3 1866 int tz;
43bc3b6c 1867 const char *p = sb->buf;
7bd9bcf3
MH
1868
1869 /* old SP new SP name <email> SP time TAB msg LF */
43bc3b6c 1870 if (!sb->len || sb->buf[sb->len - 1] != '\n' ||
1871 parse_oid_hex(p, &ooid, &p) || *p++ != ' ' ||
1872 parse_oid_hex(p, &noid, &p) || *p++ != ' ' ||
1873 !(email_end = strchr(p, '>')) ||
7bd9bcf3 1874 email_end[1] != ' ' ||
1aeb7e75 1875 !(timestamp = parse_timestamp(email_end + 2, &message, 10)) ||
7bd9bcf3
MH
1876 !message || message[0] != ' ' ||
1877 (message[1] != '+' && message[1] != '-') ||
1878 !isdigit(message[2]) || !isdigit(message[3]) ||
1879 !isdigit(message[4]) || !isdigit(message[5]))
1880 return 0; /* corrupt? */
1881 email_end[1] = '\0';
1882 tz = strtol(message + 1, NULL, 10);
1883 if (message[6] != '\t')
1884 message += 6;
1885 else
1886 message += 7;
43bc3b6c 1887 return fn(&ooid, &noid, p, timestamp, tz, message, cb_data);
7bd9bcf3
MH
1888}
1889
1890static char *find_beginning_of_line(char *bob, char *scan)
1891{
1892 while (bob < scan && *(--scan) != '\n')
1893 ; /* keep scanning backwards */
1894 /*
1895 * Return either beginning of the buffer, or LF at the end of
1896 * the previous line.
1897 */
1898 return scan;
1899}
1900
e3688bd6
DT
1901static int files_for_each_reflog_ent_reverse(struct ref_store *ref_store,
1902 const char *refname,
1903 each_reflog_ent_fn fn,
1904 void *cb_data)
7bd9bcf3 1905{
802de3da 1906 struct files_ref_store *refs =
9e7ec634
NTND
1907 files_downcast(ref_store, REF_STORE_READ,
1908 "for_each_reflog_ent_reverse");
7bd9bcf3
MH
1909 struct strbuf sb = STRBUF_INIT;
1910 FILE *logfp;
1911 long pos;
1912 int ret = 0, at_tail = 1;
1913
802de3da 1914 files_reflog_path(refs, &sb, refname);
e9dcc305
NTND
1915 logfp = fopen(sb.buf, "r");
1916 strbuf_release(&sb);
7bd9bcf3
MH
1917 if (!logfp)
1918 return -1;
1919
1920 /* Jump to the end */
1921 if (fseek(logfp, 0, SEEK_END) < 0)
be686f03
RS
1922 ret = error("cannot seek back reflog for %s: %s",
1923 refname, strerror(errno));
7bd9bcf3
MH
1924 pos = ftell(logfp);
1925 while (!ret && 0 < pos) {
1926 int cnt;
1927 size_t nread;
1928 char buf[BUFSIZ];
1929 char *endp, *scanp;
1930
1931 /* Fill next block from the end */
1932 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
be686f03
RS
1933 if (fseek(logfp, pos - cnt, SEEK_SET)) {
1934 ret = error("cannot seek back reflog for %s: %s",
1935 refname, strerror(errno));
1936 break;
1937 }
7bd9bcf3 1938 nread = fread(buf, cnt, 1, logfp);
be686f03
RS
1939 if (nread != 1) {
1940 ret = error("cannot read %d bytes from reflog for %s: %s",
1941 cnt, refname, strerror(errno));
1942 break;
1943 }
7bd9bcf3
MH
1944 pos -= cnt;
1945
1946 scanp = endp = buf + cnt;
1947 if (at_tail && scanp[-1] == '\n')
1948 /* Looking at the final LF at the end of the file */
1949 scanp--;
1950 at_tail = 0;
1951
1952 while (buf < scanp) {
1953 /*
1954 * terminating LF of the previous line, or the beginning
1955 * of the buffer.
1956 */
1957 char *bp;
1958
1959 bp = find_beginning_of_line(buf, scanp);
1960
1961 if (*bp == '\n') {
1962 /*
1963 * The newline is the end of the previous line,
1964 * so we know we have complete line starting
1965 * at (bp + 1). Prefix it onto any prior data
1966 * we collected for the line and process it.
1967 */
1968 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
1969 scanp = bp;
1970 endp = bp + 1;
1971 ret = show_one_reflog_ent(&sb, fn, cb_data);
1972 strbuf_reset(&sb);
1973 if (ret)
1974 break;
1975 } else if (!pos) {
1976 /*
1977 * We are at the start of the buffer, and the
1978 * start of the file; there is no previous
1979 * line, and we have everything for this one.
1980 * Process it, and we can end the loop.
1981 */
1982 strbuf_splice(&sb, 0, 0, buf, endp - buf);
1983 ret = show_one_reflog_ent(&sb, fn, cb_data);
1984 strbuf_reset(&sb);
1985 break;
1986 }
1987
1988 if (bp == buf) {
1989 /*
1990 * We are at the start of the buffer, and there
1991 * is more file to read backwards. Which means
1992 * we are in the middle of a line. Note that we
1993 * may get here even if *bp was a newline; that
1994 * just means we are at the exact end of the
1995 * previous line, rather than some spot in the
1996 * middle.
1997 *
1998 * Save away what we have to be combined with
1999 * the data from the next read.
2000 */
2001 strbuf_splice(&sb, 0, 0, buf, endp - buf);
2002 break;
2003 }
2004 }
2005
2006 }
2007 if (!ret && sb.len)
2008 die("BUG: reverse reflog parser had leftover data");
2009
2010 fclose(logfp);
2011 strbuf_release(&sb);
2012 return ret;
2013}
2014
e3688bd6
DT
2015static int files_for_each_reflog_ent(struct ref_store *ref_store,
2016 const char *refname,
2017 each_reflog_ent_fn fn, void *cb_data)
7bd9bcf3 2018{
802de3da 2019 struct files_ref_store *refs =
9e7ec634
NTND
2020 files_downcast(ref_store, REF_STORE_READ,
2021 "for_each_reflog_ent");
7bd9bcf3
MH
2022 FILE *logfp;
2023 struct strbuf sb = STRBUF_INIT;
2024 int ret = 0;
2025
802de3da 2026 files_reflog_path(refs, &sb, refname);
e9dcc305
NTND
2027 logfp = fopen(sb.buf, "r");
2028 strbuf_release(&sb);
7bd9bcf3
MH
2029 if (!logfp)
2030 return -1;
2031
2032 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
2033 ret = show_one_reflog_ent(&sb, fn, cb_data);
2034 fclose(logfp);
2035 strbuf_release(&sb);
2036 return ret;
2037}
7bd9bcf3 2038
2880d16f
MH
2039struct files_reflog_iterator {
2040 struct ref_iterator base;
7bd9bcf3 2041
2f40e954 2042 struct ref_store *ref_store;
2880d16f
MH
2043 struct dir_iterator *dir_iterator;
2044 struct object_id oid;
2045};
7bd9bcf3 2046
2880d16f
MH
2047static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
2048{
2049 struct files_reflog_iterator *iter =
2050 (struct files_reflog_iterator *)ref_iterator;
2051 struct dir_iterator *diter = iter->dir_iterator;
2052 int ok;
2053
2054 while ((ok = dir_iterator_advance(diter)) == ITER_OK) {
2055 int flags;
2056
2057 if (!S_ISREG(diter->st.st_mode))
7bd9bcf3 2058 continue;
2880d16f
MH
2059 if (diter->basename[0] == '.')
2060 continue;
2061 if (ends_with(diter->basename, ".lock"))
7bd9bcf3 2062 continue;
7bd9bcf3 2063
2f40e954
NTND
2064 if (refs_read_ref_full(iter->ref_store,
2065 diter->relative_path, 0,
34c290a6 2066 &iter->oid, &flags)) {
2880d16f
MH
2067 error("bad ref for %s", diter->path.buf);
2068 continue;
7bd9bcf3 2069 }
2880d16f
MH
2070
2071 iter->base.refname = diter->relative_path;
2072 iter->base.oid = &iter->oid;
2073 iter->base.flags = flags;
2074 return ITER_OK;
7bd9bcf3 2075 }
2880d16f
MH
2076
2077 iter->dir_iterator = NULL;
2078 if (ref_iterator_abort(ref_iterator) == ITER_ERROR)
2079 ok = ITER_ERROR;
2080 return ok;
2081}
2082
2083static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,
2084 struct object_id *peeled)
2085{
2086 die("BUG: ref_iterator_peel() called for reflog_iterator");
2087}
2088
2089static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)
2090{
2091 struct files_reflog_iterator *iter =
2092 (struct files_reflog_iterator *)ref_iterator;
2093 int ok = ITER_DONE;
2094
2095 if (iter->dir_iterator)
2096 ok = dir_iterator_abort(iter->dir_iterator);
2097
2098 base_ref_iterator_free(ref_iterator);
2099 return ok;
2100}
2101
2102static struct ref_iterator_vtable files_reflog_iterator_vtable = {
2103 files_reflog_iterator_advance,
2104 files_reflog_iterator_peel,
2105 files_reflog_iterator_abort
2106};
2107
944b4e30
NTND
2108static struct ref_iterator *reflog_iterator_begin(struct ref_store *ref_store,
2109 const char *gitdir)
2880d16f
MH
2110{
2111 struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));
2112 struct ref_iterator *ref_iterator = &iter->base;
e9dcc305 2113 struct strbuf sb = STRBUF_INIT;
2880d16f 2114
8738a8a4 2115 base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable, 0);
944b4e30 2116 strbuf_addf(&sb, "%s/logs", gitdir);
e9dcc305 2117 iter->dir_iterator = dir_iterator_begin(sb.buf);
2f40e954 2118 iter->ref_store = ref_store;
e9dcc305 2119 strbuf_release(&sb);
944b4e30 2120
2880d16f 2121 return ref_iterator;
7bd9bcf3
MH
2122}
2123
944b4e30
NTND
2124static enum iterator_selection reflog_iterator_select(
2125 struct ref_iterator *iter_worktree,
2126 struct ref_iterator *iter_common,
2127 void *cb_data)
2128{
2129 if (iter_worktree) {
2130 /*
2131 * We're a bit loose here. We probably should ignore
2132 * common refs if they are accidentally added as
2133 * per-worktree refs.
2134 */
2135 return ITER_SELECT_0;
2136 } else if (iter_common) {
2137 if (ref_type(iter_common->refname) == REF_TYPE_NORMAL)
2138 return ITER_SELECT_1;
2139
2140 /*
2141 * The main ref store may contain main worktree's
2142 * per-worktree refs, which should be ignored
2143 */
2144 return ITER_SKIP_1;
2145 } else
2146 return ITER_DONE;
2147}
2148
2149static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)
2150{
2151 struct files_ref_store *refs =
2152 files_downcast(ref_store, REF_STORE_READ,
2153 "reflog_iterator_begin");
2154
2155 if (!strcmp(refs->gitdir, refs->gitcommondir)) {
2156 return reflog_iterator_begin(ref_store, refs->gitcommondir);
2157 } else {
2158 return merge_ref_iterator_begin(
1a2e1a76 2159 0,
944b4e30
NTND
2160 reflog_iterator_begin(ref_store, refs->gitdir),
2161 reflog_iterator_begin(ref_store, refs->gitcommondir),
2162 reflog_iterator_select, refs);
2163 }
2164}
2165
165056b2 2166/*
92b1551b
MH
2167 * If update is a direct update of head_ref (the reference pointed to
2168 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.
2169 */
2170static int split_head_update(struct ref_update *update,
2171 struct ref_transaction *transaction,
2172 const char *head_ref,
2173 struct string_list *affected_refnames,
2174 struct strbuf *err)
2175{
2176 struct string_list_item *item;
2177 struct ref_update *new_update;
2178
2179 if ((update->flags & REF_LOG_ONLY) ||
2180 (update->flags & REF_ISPRUNING) ||
2181 (update->flags & REF_UPDATE_VIA_HEAD))
2182 return 0;
2183
2184 if (strcmp(update->refname, head_ref))
2185 return 0;
2186
2187 /*
2188 * First make sure that HEAD is not already in the
276d0e35 2189 * transaction. This check is O(lg N) in the transaction
92b1551b
MH
2190 * size, but it happens at most once per transaction.
2191 */
276d0e35 2192 if (string_list_has_string(affected_refnames, "HEAD")) {
92b1551b
MH
2193 /* An entry already existed */
2194 strbuf_addf(err,
2195 "multiple updates for 'HEAD' (including one "
2196 "via its referent '%s') are not allowed",
2197 update->refname);
2198 return TRANSACTION_NAME_CONFLICT;
2199 }
2200
2201 new_update = ref_transaction_add_update(
2202 transaction, "HEAD",
2203 update->flags | REF_LOG_ONLY | REF_NODEREF,
89f3bbdd 2204 &update->new_oid, &update->old_oid,
92b1551b
MH
2205 update->msg);
2206
276d0e35
2207 /*
2208 * Add "HEAD". This insertion is O(N) in the transaction
2209 * size, but it happens at most once per transaction.
2210 * Add new_update->refname instead of a literal "HEAD".
2211 */
2212 if (strcmp(new_update->refname, "HEAD"))
2213 BUG("%s unexpectedly not 'HEAD'", new_update->refname);
2214 item = string_list_insert(affected_refnames, new_update->refname);
92b1551b
MH
2215 item->util = new_update;
2216
2217 return 0;
2218}
2219
2220/*
2221 * update is for a symref that points at referent and doesn't have
2222 * REF_NODEREF set. Split it into two updates:
2223 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set
2224 * - A new, separate update for the referent reference
2225 * Note that the new update will itself be subject to splitting when
2226 * the iteration gets to it.
2227 */
fcc42ea0
MH
2228static int split_symref_update(struct files_ref_store *refs,
2229 struct ref_update *update,
92b1551b
MH
2230 const char *referent,
2231 struct ref_transaction *transaction,
2232 struct string_list *affected_refnames,
2233 struct strbuf *err)
2234{
2235 struct string_list_item *item;
2236 struct ref_update *new_update;
2237 unsigned int new_flags;
2238
2239 /*
2240 * First make sure that referent is not already in the
c299468b 2241 * transaction. This check is O(lg N) in the transaction
92b1551b
MH
2242 * size, but it happens at most once per symref in a
2243 * transaction.
2244 */
c299468b
2245 if (string_list_has_string(affected_refnames, referent)) {
2246 /* An entry already exists */
92b1551b
MH
2247 strbuf_addf(err,
2248 "multiple updates for '%s' (including one "
2249 "via symref '%s') are not allowed",
2250 referent, update->refname);
2251 return TRANSACTION_NAME_CONFLICT;
2252 }
2253
2254 new_flags = update->flags;
2255 if (!strcmp(update->refname, "HEAD")) {
2256 /*
2257 * Record that the new update came via HEAD, so that
2258 * when we process it, split_head_update() doesn't try
2259 * to add another reflog update for HEAD. Note that
2260 * this bit will be propagated if the new_update
2261 * itself needs to be split.
2262 */
2263 new_flags |= REF_UPDATE_VIA_HEAD;
2264 }
2265
2266 new_update = ref_transaction_add_update(
2267 transaction, referent, new_flags,
89f3bbdd 2268 &update->new_oid, &update->old_oid,
92b1551b
MH
2269 update->msg);
2270
6e30b2f6
MH
2271 new_update->parent_update = update;
2272
2273 /*
2274 * Change the symbolic ref update to log only. Also, it
2275 * doesn't need to check its old SHA-1 value, as that will be
2276 * done when new_update is processed.
2277 */
92b1551b 2278 update->flags |= REF_LOG_ONLY | REF_NODEREF;
6e30b2f6 2279 update->flags &= ~REF_HAVE_OLD;
92b1551b 2280
c299468b
2281 /*
2282 * Add the referent. This insertion is O(N) in the transaction
2283 * size, but it happens at most once per symref in a
2284 * transaction. Make sure to add new_update->refname, which will
2285 * be valid as long as affected_refnames is in use, and NOT
2286 * referent, which might soon be freed by our caller.
2287 */
2288 item = string_list_insert(affected_refnames, new_update->refname);
2289 if (item->util)
2290 BUG("%s unexpectedly found in affected_refnames",
2291 new_update->refname);
92b1551b
MH
2292 item->util = new_update;
2293
2294 return 0;
2295}
2296
6e30b2f6
MH
2297/*
2298 * Return the refname under which update was originally requested.
2299 */
2300static const char *original_update_refname(struct ref_update *update)
2301{
2302 while (update->parent_update)
2303 update = update->parent_update;
2304
2305 return update->refname;
2306}
2307
e3f51039
MH
2308/*
2309 * Check whether the REF_HAVE_OLD and old_oid values stored in update
2310 * are consistent with oid, which is the reference's current value. If
2311 * everything is OK, return 0; otherwise, write an error message to
2312 * err and return -1.
2313 */
2314static int check_old_oid(struct ref_update *update, struct object_id *oid,
2315 struct strbuf *err)
2316{
2317 if (!(update->flags & REF_HAVE_OLD) ||
98491298 2318 !oidcmp(oid, &update->old_oid))
e3f51039
MH
2319 return 0;
2320
98491298 2321 if (is_null_oid(&update->old_oid))
e3f51039
MH
2322 strbuf_addf(err, "cannot lock ref '%s': "
2323 "reference already exists",
2324 original_update_refname(update));
2325 else if (is_null_oid(oid))
2326 strbuf_addf(err, "cannot lock ref '%s': "
2327 "reference is missing but expected %s",
2328 original_update_refname(update),
98491298 2329 oid_to_hex(&update->old_oid));
e3f51039
MH
2330 else
2331 strbuf_addf(err, "cannot lock ref '%s': "
2332 "is at %s but expected %s",
2333 original_update_refname(update),
2334 oid_to_hex(oid),
98491298 2335 oid_to_hex(&update->old_oid));
e3f51039
MH
2336
2337 return -1;
2338}
2339
92b1551b
MH
2340/*
2341 * Prepare for carrying out update:
2342 * - Lock the reference referred to by update.
2343 * - Read the reference under lock.
2344 * - Check that its old SHA-1 value (if specified) is correct, and in
2345 * any case record it in update->lock->old_oid for later use when
2346 * writing the reflog.
2347 * - If it is a symref update without REF_NODEREF, split it up into a
2348 * REF_LOG_ONLY update of the symref and add a separate update for
2349 * the referent to transaction.
2350 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY
2351 * update of HEAD.
165056b2 2352 */
b3bbbc5c
MH
2353static int lock_ref_for_update(struct files_ref_store *refs,
2354 struct ref_update *update,
165056b2 2355 struct ref_transaction *transaction,
92b1551b 2356 const char *head_ref,
165056b2
MH
2357 struct string_list *affected_refnames,
2358 struct strbuf *err)
2359{
92b1551b
MH
2360 struct strbuf referent = STRBUF_INIT;
2361 int mustexist = (update->flags & REF_HAVE_OLD) &&
98491298 2362 !is_null_oid(&update->old_oid);
851e1fbd 2363 int ret = 0;
92b1551b 2364 struct ref_lock *lock;
165056b2 2365
32c597e7 2366 files_assert_main_repository(refs, "lock_ref_for_update");
b3bbbc5c 2367
98491298 2368 if ((update->flags & REF_HAVE_NEW) && is_null_oid(&update->new_oid))
165056b2 2369 update->flags |= REF_DELETING;
92b1551b
MH
2370
2371 if (head_ref) {
2372 ret = split_head_update(update, transaction, head_ref,
2373 affected_refnames, err);
2374 if (ret)
851e1fbd 2375 goto out;
92b1551b
MH
2376 }
2377
f7b0a987 2378 ret = lock_raw_ref(refs, update->refname, mustexist,
92b1551b 2379 affected_refnames, NULL,
7d618264 2380 &lock, &referent,
92b1551b 2381 &update->type, err);
92b1551b 2382 if (ret) {
165056b2
MH
2383 char *reason;
2384
165056b2
MH
2385 reason = strbuf_detach(err, NULL);
2386 strbuf_addf(err, "cannot lock ref '%s': %s",
e3f51039 2387 original_update_refname(update), reason);
165056b2 2388 free(reason);
851e1fbd 2389 goto out;
165056b2 2390 }
92b1551b 2391
7d618264 2392 update->backend_data = lock;
92b1551b 2393
8169d0d0 2394 if (update->type & REF_ISSYMREF) {
6e30b2f6
MH
2395 if (update->flags & REF_NODEREF) {
2396 /*
2397 * We won't be reading the referent as part of
2398 * the transaction, so we have to read it here
2399 * to record and possibly check old_sha1:
2400 */
2f40e954
NTND
2401 if (refs_read_ref_full(&refs->base,
2402 referent.buf, 0,
34c290a6 2403 &lock->old_oid, NULL)) {
6e30b2f6
MH
2404 if (update->flags & REF_HAVE_OLD) {
2405 strbuf_addf(err, "cannot lock ref '%s': "
e3f51039
MH
2406 "error reading reference",
2407 original_update_refname(update));
3f5ef95b 2408 ret = TRANSACTION_GENERIC_ERROR;
851e1fbd 2409 goto out;
6e30b2f6 2410 }
e3f51039 2411 } else if (check_old_oid(update, &lock->old_oid, err)) {
851e1fbd
2412 ret = TRANSACTION_GENERIC_ERROR;
2413 goto out;
8169d0d0 2414 }
6e30b2f6
MH
2415 } else {
2416 /*
2417 * Create a new update for the reference this
2418 * symref is pointing at. Also, we will record
2419 * and verify old_sha1 for this update as part
2420 * of processing the split-off update, so we
2421 * don't have to do it here.
2422 */
fcc42ea0
MH
2423 ret = split_symref_update(refs, update,
2424 referent.buf, transaction,
92b1551b
MH
2425 affected_refnames, err);
2426 if (ret)
851e1fbd 2427 goto out;
92b1551b 2428 }
6e30b2f6
MH
2429 } else {
2430 struct ref_update *parent_update;
8169d0d0 2431
851e1fbd
2432 if (check_old_oid(update, &lock->old_oid, err)) {
2433 ret = TRANSACTION_GENERIC_ERROR;
2434 goto out;
2435 }
e3f51039 2436
6e30b2f6
MH
2437 /*
2438 * If this update is happening indirectly because of a
2439 * symref update, record the old SHA-1 in the parent
2440 * update:
2441 */
2442 for (parent_update = update->parent_update;
2443 parent_update;
2444 parent_update = parent_update->parent_update) {
7d618264
DT
2445 struct ref_lock *parent_lock = parent_update->backend_data;
2446 oidcpy(&parent_lock->old_oid, &lock->old_oid);
6e30b2f6 2447 }
92b1551b
MH
2448 }
2449
165056b2
MH
2450 if ((update->flags & REF_HAVE_NEW) &&
2451 !(update->flags & REF_DELETING) &&
2452 !(update->flags & REF_LOG_ONLY)) {
92b1551b 2453 if (!(update->type & REF_ISSYMREF) &&
98491298 2454 !oidcmp(&lock->old_oid, &update->new_oid)) {
165056b2
MH
2455 /*
2456 * The reference already has the desired
2457 * value, so we don't need to write it.
2458 */
4417df8c 2459 } else if (write_ref_to_lockfile(lock, &update->new_oid,
165056b2
MH
2460 err)) {
2461 char *write_err = strbuf_detach(err, NULL);
2462
2463 /*
2464 * The lock was freed upon failure of
2465 * write_ref_to_lockfile():
2466 */
7d618264 2467 update->backend_data = NULL;
165056b2 2468 strbuf_addf(err,
e3f51039 2469 "cannot update ref '%s': %s",
165056b2
MH
2470 update->refname, write_err);
2471 free(write_err);
851e1fbd
2472 ret = TRANSACTION_GENERIC_ERROR;
2473 goto out;
165056b2
MH
2474 } else {
2475 update->flags |= REF_NEEDS_COMMIT;
2476 }
2477 }
2478 if (!(update->flags & REF_NEEDS_COMMIT)) {
2479 /*
2480 * We didn't call write_ref_to_lockfile(), so
2481 * the lockfile is still open. Close it to
2482 * free up the file descriptor:
2483 */
83a3069a 2484 if (close_ref_gently(lock)) {
165056b2
MH
2485 strbuf_addf(err, "couldn't close '%s.lock'",
2486 update->refname);
851e1fbd
2487 ret = TRANSACTION_GENERIC_ERROR;
2488 goto out;
165056b2
MH
2489 }
2490 }
851e1fbd
2491
2492out:
2493 strbuf_release(&referent);
2494 return ret;
165056b2
MH
2495}
2496
dc39e099
MH
2497struct files_transaction_backend_data {
2498 struct ref_transaction *packed_transaction;
2499 int packed_refs_locked;
2500};
2501
c0ca9357
MH
2502/*
2503 * Unlock any references in `transaction` that are still locked, and
2504 * mark the transaction closed.
2505 */
dc39e099
MH
2506static void files_transaction_cleanup(struct files_ref_store *refs,
2507 struct ref_transaction *transaction)
c0ca9357
MH
2508{
2509 size_t i;
dc39e099
MH
2510 struct files_transaction_backend_data *backend_data =
2511 transaction->backend_data;
2512 struct strbuf err = STRBUF_INIT;
c0ca9357
MH
2513
2514 for (i = 0; i < transaction->nr; i++) {
2515 struct ref_update *update = transaction->updates[i];
2516 struct ref_lock *lock = update->backend_data;
2517
2518 if (lock) {
2519 unlock_ref(lock);
2520 update->backend_data = NULL;
2521 }
2522 }
2523
dc39e099
MH
2524 if (backend_data->packed_transaction &&
2525 ref_transaction_abort(backend_data->packed_transaction, &err)) {
2526 error("error aborting transaction: %s", err.buf);
2527 strbuf_release(&err);
2528 }
2529
2530 if (backend_data->packed_refs_locked)
2531 packed_refs_unlock(refs->packed_ref_store);
2532
2533 free(backend_data);
2534
c0ca9357
MH
2535 transaction->state = REF_TRANSACTION_CLOSED;
2536}
2537
30173b88
MH
2538static int files_transaction_prepare(struct ref_store *ref_store,
2539 struct ref_transaction *transaction,
2540 struct strbuf *err)
7bd9bcf3 2541{
00eebe35 2542 struct files_ref_store *refs =
9e7ec634 2543 files_downcast(ref_store, REF_STORE_WRITE,
30173b88 2544 "ref_transaction_prepare");
43a2dfde
MH
2545 size_t i;
2546 int ret = 0;
7bd9bcf3 2547 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
92b1551b
MH
2548 char *head_ref = NULL;
2549 int head_type;
dc39e099
MH
2550 struct files_transaction_backend_data *backend_data;
2551 struct ref_transaction *packed_transaction = NULL;
7bd9bcf3
MH
2552
2553 assert(err);
2554
c0ca9357
MH
2555 if (!transaction->nr)
2556 goto cleanup;
7bd9bcf3 2557
dc39e099
MH
2558 backend_data = xcalloc(1, sizeof(*backend_data));
2559 transaction->backend_data = backend_data;
2560
92b1551b
MH
2561 /*
2562 * Fail if a refname appears more than once in the
2563 * transaction. (If we end up splitting up any updates using
2564 * split_symref_update() or split_head_update(), those
2565 * functions will check that the new updates don't have the
62c72d1f
MH
2566 * same refname as any existing ones.) Also fail if any of the
2567 * updates use REF_ISPRUNING without REF_NODEREF.
92b1551b
MH
2568 */
2569 for (i = 0; i < transaction->nr; i++) {
2570 struct ref_update *update = transaction->updates[i];
2571 struct string_list_item *item =
2572 string_list_append(&affected_refnames, update->refname);
2573
62c72d1f
MH
2574 if ((update->flags & REF_ISPRUNING) &&
2575 !(update->flags & REF_NODEREF))
2576 BUG("REF_ISPRUNING set without REF_NODEREF");
2577
92b1551b
MH
2578 /*
2579 * We store a pointer to update in item->util, but at
2580 * the moment we never use the value of this field
2581 * except to check whether it is non-NULL.
2582 */
2583 item->util = update;
2584 }
7bd9bcf3
MH
2585 string_list_sort(&affected_refnames);
2586 if (ref_update_reject_duplicates(&affected_refnames, err)) {
2587 ret = TRANSACTION_GENERIC_ERROR;
2588 goto cleanup;
2589 }
2590
92b1551b
MH
2591 /*
2592 * Special hack: If a branch is updated directly and HEAD
2593 * points to it (may happen on the remote side of a push
2594 * for example) then logically the HEAD reflog should be
2595 * updated too.
2596 *
2597 * A generic solution would require reverse symref lookups,
2598 * but finding all symrefs pointing to a given branch would be
2599 * rather costly for this rare event (the direct update of a
2600 * branch) to be worth it. So let's cheat and check with HEAD
2601 * only, which should cover 99% of all usage scenarios (even
2602 * 100% of the default ones).
2603 *
2604 * So if HEAD is a symbolic reference, then record the name of
2605 * the reference that it points to. If we see an update of
2606 * head_ref within the transaction, then split_head_update()
2607 * arranges for the reflog of HEAD to be updated, too.
2608 */
2f40e954
NTND
2609 head_ref = refs_resolve_refdup(ref_store, "HEAD",
2610 RESOLVE_REF_NO_RECURSE,
872ccb2c 2611 NULL, &head_type);
92b1551b
MH
2612
2613 if (head_ref && !(head_type & REF_ISSYMREF)) {
6a83d902 2614 FREE_AND_NULL(head_ref);
92b1551b
MH
2615 }
2616
7bd9bcf3
MH
2617 /*
2618 * Acquire all locks, verify old values if provided, check
2619 * that new values are valid, and write new values to the
2620 * lockfiles, ready to be activated. Only keep one lockfile
2621 * open at a time to avoid running out of file descriptors.
30173b88
MH
2622 * Note that lock_ref_for_update() might append more updates
2623 * to the transaction.
7bd9bcf3 2624 */
efe47281
MH
2625 for (i = 0; i < transaction->nr; i++) {
2626 struct ref_update *update = transaction->updates[i];
7bd9bcf3 2627
b3bbbc5c
MH
2628 ret = lock_ref_for_update(refs, update, transaction,
2629 head_ref, &affected_refnames, err);
165056b2 2630 if (ret)
da5267f1 2631 goto cleanup;
dc39e099
MH
2632
2633 if (update->flags & REF_DELETING &&
2634 !(update->flags & REF_LOG_ONLY) &&
2635 !(update->flags & REF_ISPRUNING)) {
2636 /*
2637 * This reference has to be deleted from
2638 * packed-refs if it exists there.
2639 */
2640 if (!packed_transaction) {
2641 packed_transaction = ref_store_transaction_begin(
2642 refs->packed_ref_store, err);
2643 if (!packed_transaction) {
2644 ret = TRANSACTION_GENERIC_ERROR;
2645 goto cleanup;
2646 }
2647
2648 backend_data->packed_transaction =
2649 packed_transaction;
2650 }
2651
2652 ref_transaction_add_update(
2653 packed_transaction, update->refname,
b0ca4110
MH
2654 REF_HAVE_NEW | REF_NODEREF,
2655 &update->new_oid, NULL,
dc39e099
MH
2656 NULL);
2657 }
2658 }
2659
2660 if (packed_transaction) {
2661 if (packed_refs_lock(refs->packed_ref_store, 0, err)) {
2662 ret = TRANSACTION_GENERIC_ERROR;
2663 goto cleanup;
2664 }
2665 backend_data->packed_refs_locked = 1;
2666 ret = ref_transaction_prepare(packed_transaction, err);
30173b88
MH
2667 }
2668
2669cleanup:
2670 free(head_ref);
2671 string_list_clear(&affected_refnames, 0);
2672
2673 if (ret)
dc39e099 2674 files_transaction_cleanup(refs, transaction);
30173b88
MH
2675 else
2676 transaction->state = REF_TRANSACTION_PREPARED;
2677
2678 return ret;
2679}
2680
2681static int files_transaction_finish(struct ref_store *ref_store,
2682 struct ref_transaction *transaction,
2683 struct strbuf *err)
2684{
2685 struct files_ref_store *refs =
2686 files_downcast(ref_store, 0, "ref_transaction_finish");
2687 size_t i;
2688 int ret = 0;
30173b88 2689 struct strbuf sb = STRBUF_INIT;
dc39e099
MH
2690 struct files_transaction_backend_data *backend_data;
2691 struct ref_transaction *packed_transaction;
2692
30173b88
MH
2693
2694 assert(err);
2695
2696 if (!transaction->nr) {
2697 transaction->state = REF_TRANSACTION_CLOSED;
2698 return 0;
7bd9bcf3 2699 }
7bd9bcf3 2700
dc39e099
MH
2701 backend_data = transaction->backend_data;
2702 packed_transaction = backend_data->packed_transaction;
2703
7bd9bcf3 2704 /* Perform updates first so live commits remain referenced */
efe47281
MH
2705 for (i = 0; i < transaction->nr; i++) {
2706 struct ref_update *update = transaction->updates[i];
7d618264 2707 struct ref_lock *lock = update->backend_data;
7bd9bcf3 2708
d99aa884
DT
2709 if (update->flags & REF_NEEDS_COMMIT ||
2710 update->flags & REF_LOG_ONLY) {
802de3da
NTND
2711 if (files_log_ref_write(refs,
2712 lock->ref_name,
4417df8c 2713 &lock->old_oid,
2714 &update->new_oid,
81b1b6d4
MH
2715 update->msg, update->flags,
2716 err)) {
92b1551b
MH
2717 char *old_msg = strbuf_detach(err, NULL);
2718
2719 strbuf_addf(err, "cannot update the ref '%s': %s",
2720 lock->ref_name, old_msg);
2721 free(old_msg);
2722 unlock_ref(lock);
7d618264 2723 update->backend_data = NULL;
7bd9bcf3
MH
2724 ret = TRANSACTION_GENERIC_ERROR;
2725 goto cleanup;
7bd9bcf3
MH
2726 }
2727 }
7bd9bcf3 2728 if (update->flags & REF_NEEDS_COMMIT) {
00eebe35 2729 clear_loose_ref_cache(refs);
92b1551b
MH
2730 if (commit_ref(lock)) {
2731 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
2732 unlock_ref(lock);
7d618264 2733 update->backend_data = NULL;
7bd9bcf3
MH
2734 ret = TRANSACTION_GENERIC_ERROR;
2735 goto cleanup;
7bd9bcf3
MH
2736 }
2737 }
2738 }
dc39e099 2739
5e00a6c8
MH
2740 /*
2741 * Now that updates are safely completed, we can perform
2742 * deletes. First delete the reflogs of any references that
2743 * will be deleted, since (in the unexpected event of an
2744 * error) leaving a reference without a reflog is less bad
2745 * than leaving a reflog without a reference (the latter is a
2746 * mildly invalid repository state):
2747 */
2748 for (i = 0; i < transaction->nr; i++) {
2749 struct ref_update *update = transaction->updates[i];
2750 if (update->flags & REF_DELETING &&
2751 !(update->flags & REF_LOG_ONLY) &&
2752 !(update->flags & REF_ISPRUNING)) {
2753 strbuf_reset(&sb);
2754 files_reflog_path(refs, &sb, update->refname);
2755 if (!unlink_or_warn(sb.buf))
2756 try_remove_empty_parents(refs, update->refname,
2757 REMOVE_EMPTY_PARENTS_REFLOG);
2758 }
2759 }
2760
dc39e099
MH
2761 /*
2762 * Perform deletes now that updates are safely completed.
2763 *
2764 * First delete any packed versions of the references, while
2765 * retaining the packed-refs lock:
2766 */
2767 if (packed_transaction) {
2768 ret = ref_transaction_commit(packed_transaction, err);
2769 ref_transaction_free(packed_transaction);
2770 packed_transaction = NULL;
2771 backend_data->packed_transaction = NULL;
2772 if (ret)
2773 goto cleanup;
2774 }
2775
2776 /* Now delete the loose versions of the references: */
efe47281
MH
2777 for (i = 0; i < transaction->nr; i++) {
2778 struct ref_update *update = transaction->updates[i];
7d618264 2779 struct ref_lock *lock = update->backend_data;
7bd9bcf3 2780
d99aa884
DT
2781 if (update->flags & REF_DELETING &&
2782 !(update->flags & REF_LOG_ONLY)) {
ce0af24d
MH
2783 if (!(update->type & REF_ISPACKED) ||
2784 update->type & REF_ISSYMREF) {
2785 /* It is a loose reference. */
e9dcc305 2786 strbuf_reset(&sb);
19e02f4f 2787 files_ref_path(refs, &sb, lock->ref_name);
e9dcc305 2788 if (unlink_or_msg(sb.buf, err)) {
ce0af24d
MH
2789 ret = TRANSACTION_GENERIC_ERROR;
2790 goto cleanup;
2791 }
44639777 2792 update->flags |= REF_DELETED_LOOSE;
7bd9bcf3 2793 }
7bd9bcf3
MH
2794 }
2795 }
2796
00eebe35 2797 clear_loose_ref_cache(refs);
7bd9bcf3
MH
2798
2799cleanup:
dc39e099 2800 files_transaction_cleanup(refs, transaction);
7bd9bcf3 2801
44639777
MH
2802 for (i = 0; i < transaction->nr; i++) {
2803 struct ref_update *update = transaction->updates[i];
44639777
MH
2804
2805 if (update->flags & REF_DELETED_LOOSE) {
2806 /*
2807 * The loose reference was deleted. Delete any
2808 * empty parent directories. (Note that this
2809 * can only work because we have already
2810 * removed the lockfile.)
2811 */
802de3da 2812 try_remove_empty_parents(refs, update->refname,
44639777
MH
2813 REMOVE_EMPTY_PARENTS_REF);
2814 }
2815 }
2816
30173b88 2817 strbuf_release(&sb);
7bd9bcf3
MH
2818 return ret;
2819}
2820
30173b88
MH
2821static int files_transaction_abort(struct ref_store *ref_store,
2822 struct ref_transaction *transaction,
2823 struct strbuf *err)
2824{
dc39e099
MH
2825 struct files_ref_store *refs =
2826 files_downcast(ref_store, 0, "ref_transaction_abort");
2827
2828 files_transaction_cleanup(refs, transaction);
30173b88
MH
2829 return 0;
2830}
2831
7bd9bcf3
MH
2832static int ref_present(const char *refname,
2833 const struct object_id *oid, int flags, void *cb_data)
2834{
2835 struct string_list *affected_refnames = cb_data;
2836
2837 return string_list_has_string(affected_refnames, refname);
2838}
2839
fc681463
DT
2840static int files_initial_transaction_commit(struct ref_store *ref_store,
2841 struct ref_transaction *transaction,
2842 struct strbuf *err)
7bd9bcf3 2843{
d99825ab 2844 struct files_ref_store *refs =
9e7ec634
NTND
2845 files_downcast(ref_store, REF_STORE_WRITE,
2846 "initial_ref_transaction_commit");
43a2dfde
MH
2847 size_t i;
2848 int ret = 0;
7bd9bcf3 2849 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
1444bfe0 2850 struct ref_transaction *packed_transaction = NULL;
7bd9bcf3
MH
2851
2852 assert(err);
2853
2854 if (transaction->state != REF_TRANSACTION_OPEN)
2855 die("BUG: commit called for transaction that is not open");
2856
2857 /* Fail if a refname appears more than once in the transaction: */
efe47281
MH
2858 for (i = 0; i < transaction->nr; i++)
2859 string_list_append(&affected_refnames,
2860 transaction->updates[i]->refname);
7bd9bcf3
MH
2861 string_list_sort(&affected_refnames);
2862 if (ref_update_reject_duplicates(&affected_refnames, err)) {
2863 ret = TRANSACTION_GENERIC_ERROR;
2864 goto cleanup;
2865 }
2866
2867 /*
2868 * It's really undefined to call this function in an active
2869 * repository or when there are existing references: we are
2870 * only locking and changing packed-refs, so (1) any
2871 * simultaneous processes might try to change a reference at
2872 * the same time we do, and (2) any existing loose versions of
2873 * the references that we are setting would have precedence
2874 * over our values. But some remote helpers create the remote
2875 * "HEAD" and "master" branches before calling this function,
2876 * so here we really only check that none of the references
2877 * that we are creating already exists.
2878 */
2f40e954
NTND
2879 if (refs_for_each_rawref(&refs->base, ref_present,
2880 &affected_refnames))
7bd9bcf3
MH
2881 die("BUG: initial ref transaction called with existing refs");
2882
1444bfe0
MH
2883 packed_transaction = ref_store_transaction_begin(refs->packed_ref_store, err);
2884 if (!packed_transaction) {
2885 ret = TRANSACTION_GENERIC_ERROR;
2886 goto cleanup;
2887 }
2888
efe47281
MH
2889 for (i = 0; i < transaction->nr; i++) {
2890 struct ref_update *update = transaction->updates[i];
7bd9bcf3
MH
2891
2892 if ((update->flags & REF_HAVE_OLD) &&
98491298 2893 !is_null_oid(&update->old_oid))
7bd9bcf3 2894 die("BUG: initial ref transaction with old_sha1 set");
7d2df051
NTND
2895 if (refs_verify_refname_available(&refs->base, update->refname,
2896 &affected_refnames, NULL,
2897 err)) {
7bd9bcf3
MH
2898 ret = TRANSACTION_NAME_CONFLICT;
2899 goto cleanup;
2900 }
1444bfe0
MH
2901
2902 /*
2903 * Add a reference creation for this reference to the
2904 * packed-refs transaction:
2905 */
2906 ref_transaction_add_update(packed_transaction, update->refname,
2907 update->flags & ~REF_HAVE_OLD,
89f3bbdd 2908 &update->new_oid, &update->old_oid,
1444bfe0 2909 NULL);
7bd9bcf3
MH
2910 }
2911
c8bed835 2912 if (packed_refs_lock(refs->packed_ref_store, 0, err)) {
7bd9bcf3
MH
2913 ret = TRANSACTION_GENERIC_ERROR;
2914 goto cleanup;
2915 }
2916
1444bfe0 2917 if (initial_ref_transaction_commit(packed_transaction, err)) {
7bd9bcf3
MH
2918 ret = TRANSACTION_GENERIC_ERROR;
2919 goto cleanup;
2920 }
2921
2922cleanup:
1444bfe0
MH
2923 if (packed_transaction)
2924 ref_transaction_free(packed_transaction);
42c7f7ff 2925 packed_refs_unlock(refs->packed_ref_store);
7bd9bcf3
MH
2926 transaction->state = REF_TRANSACTION_CLOSED;
2927 string_list_clear(&affected_refnames, 0);
2928 return ret;
2929}
2930
2931struct expire_reflog_cb {
2932 unsigned int flags;
2933 reflog_expiry_should_prune_fn *should_prune_fn;
2934 void *policy_cb;
2935 FILE *newlog;
9461d272 2936 struct object_id last_kept_oid;
7bd9bcf3
MH
2937};
2938
9461d272 2939static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
dddbad72 2940 const char *email, timestamp_t timestamp, int tz,
7bd9bcf3
MH
2941 const char *message, void *cb_data)
2942{
2943 struct expire_reflog_cb *cb = cb_data;
2944 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
2945
2946 if (cb->flags & EXPIRE_REFLOGS_REWRITE)
9461d272 2947 ooid = &cb->last_kept_oid;
7bd9bcf3 2948
4322478a 2949 if ((*cb->should_prune_fn)(ooid, noid, email, timestamp, tz,
7bd9bcf3
MH
2950 message, policy_cb)) {
2951 if (!cb->newlog)
2952 printf("would prune %s", message);
2953 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
2954 printf("prune %s", message);
2955 } else {
2956 if (cb->newlog) {
cb71f8bd 2957 fprintf(cb->newlog, "%s %s %s %"PRItime" %+05d\t%s",
9461d272 2958 oid_to_hex(ooid), oid_to_hex(noid),
7bd9bcf3 2959 email, timestamp, tz, message);
9461d272 2960 oidcpy(&cb->last_kept_oid, noid);
7bd9bcf3
MH
2961 }
2962 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
2963 printf("keep %s", message);
2964 }
2965 return 0;
2966}
2967
e3688bd6 2968static int files_reflog_expire(struct ref_store *ref_store,
0155f710 2969 const char *refname, const struct object_id *oid,
e3688bd6
DT
2970 unsigned int flags,
2971 reflog_expiry_prepare_fn prepare_fn,
2972 reflog_expiry_should_prune_fn should_prune_fn,
2973 reflog_expiry_cleanup_fn cleanup_fn,
2974 void *policy_cb_data)
7bd9bcf3 2975{
7eb27cdf 2976 struct files_ref_store *refs =
9e7ec634 2977 files_downcast(ref_store, REF_STORE_WRITE, "reflog_expire");
7bd9bcf3
MH
2978 static struct lock_file reflog_lock;
2979 struct expire_reflog_cb cb;
2980 struct ref_lock *lock;
802de3da 2981 struct strbuf log_file_sb = STRBUF_INIT;
7bd9bcf3
MH
2982 char *log_file;
2983 int status = 0;
2984 int type;
2985 struct strbuf err = STRBUF_INIT;
2986
2987 memset(&cb, 0, sizeof(cb));
2988 cb.flags = flags;
2989 cb.policy_cb = policy_cb_data;
2990 cb.should_prune_fn = should_prune_fn;
2991
2992 /*
2993 * The reflog file is locked by holding the lock on the
2994 * reference itself, plus we might need to update the
2995 * reference if --updateref was specified:
2996 */
4f01e508 2997 lock = lock_ref_oid_basic(refs, refname, oid,
2998 NULL, NULL, REF_NODEREF,
2999 &type, &err);
7bd9bcf3
MH
3000 if (!lock) {
3001 error("cannot lock ref '%s': %s", refname, err.buf);
3002 strbuf_release(&err);
3003 return -1;
3004 }
2f40e954 3005 if (!refs_reflog_exists(ref_store, refname)) {
7bd9bcf3
MH
3006 unlock_ref(lock);
3007 return 0;
3008 }
3009
802de3da
NTND
3010 files_reflog_path(refs, &log_file_sb, refname);
3011 log_file = strbuf_detach(&log_file_sb, NULL);
7bd9bcf3
MH
3012 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
3013 /*
3014 * Even though holding $GIT_DIR/logs/$reflog.lock has
3015 * no locking implications, we use the lock_file
3016 * machinery here anyway because it does a lot of the
3017 * work we need, including cleaning up if the program
3018 * exits unexpectedly.
3019 */
3020 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
3021 struct strbuf err = STRBUF_INIT;
3022 unable_to_lock_message(log_file, errno, &err);
3023 error("%s", err.buf);
3024 strbuf_release(&err);
3025 goto failure;
3026 }
3027 cb.newlog = fdopen_lock_file(&reflog_lock, "w");
3028 if (!cb.newlog) {
3029 error("cannot fdopen %s (%s)",
3030 get_lock_file_path(&reflog_lock), strerror(errno));
3031 goto failure;
3032 }
3033 }
3034
0155f710 3035 (*prepare_fn)(refname, oid, cb.policy_cb);
2f40e954 3036 refs_for_each_reflog_ent(ref_store, refname, expire_reflog_ent, &cb);
7bd9bcf3
MH
3037 (*cleanup_fn)(cb.policy_cb);
3038
3039 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
3040 /*
3041 * It doesn't make sense to adjust a reference pointed
3042 * to by a symbolic ref based on expiring entries in
3043 * the symbolic reference's reflog. Nor can we update
3044 * a reference if there are no remaining reflog
3045 * entries.
3046 */
3047 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&
3048 !(type & REF_ISSYMREF) &&
9461d272 3049 !is_null_oid(&cb.last_kept_oid);
7bd9bcf3 3050
83a3069a 3051 if (close_lock_file_gently(&reflog_lock)) {
7bd9bcf3
MH
3052 status |= error("couldn't write %s: %s", log_file,
3053 strerror(errno));
83a3069a 3054 rollback_lock_file(&reflog_lock);
7bd9bcf3 3055 } else if (update &&
ee4d8e45 3056 (write_in_full(get_lock_file_fd(&lock->lk),
06f46f23 3057 oid_to_hex(&cb.last_kept_oid), GIT_SHA1_HEXSZ) < 0 ||
88780c37 3058 write_str_in_full(get_lock_file_fd(&lock->lk), "\n") < 0 ||
83a3069a 3059 close_ref_gently(lock) < 0)) {
7bd9bcf3 3060 status |= error("couldn't write %s",
ee4d8e45 3061 get_lock_file_path(&lock->lk));
7bd9bcf3
MH
3062 rollback_lock_file(&reflog_lock);
3063 } else if (commit_lock_file(&reflog_lock)) {
e0048d3e 3064 status |= error("unable to write reflog '%s' (%s)",
7bd9bcf3
MH
3065 log_file, strerror(errno));
3066 } else if (update && commit_ref(lock)) {
3067 status |= error("couldn't set %s", lock->ref_name);
3068 }
3069 }
3070 free(log_file);
3071 unlock_ref(lock);
3072 return status;
3073
3074 failure:
3075 rollback_lock_file(&reflog_lock);
3076 free(log_file);
3077 unlock_ref(lock);
3078 return -1;
3079}
3dce444f 3080
6fb5acfd
DT
3081static int files_init_db(struct ref_store *ref_store, struct strbuf *err)
3082{
19e02f4f 3083 struct files_ref_store *refs =
9e7ec634 3084 files_downcast(ref_store, REF_STORE_WRITE, "init_db");
e9dcc305
NTND
3085 struct strbuf sb = STRBUF_INIT;
3086
6fb5acfd
DT
3087 /*
3088 * Create .git/refs/{heads,tags}
3089 */
19e02f4f 3090 files_ref_path(refs, &sb, "refs/heads");
e9dcc305
NTND
3091 safe_create_dir(sb.buf, 1);
3092
3093 strbuf_reset(&sb);
19e02f4f 3094 files_ref_path(refs, &sb, "refs/tags");
e9dcc305
NTND
3095 safe_create_dir(sb.buf, 1);
3096
3097 strbuf_release(&sb);
6fb5acfd
DT
3098 return 0;
3099}
3100
3dce444f
RS
3101struct ref_storage_be refs_be_files = {
3102 NULL,
00eebe35 3103 "files",
127b42a1 3104 files_ref_store_create,
6fb5acfd 3105 files_init_db,
30173b88
MH
3106 files_transaction_prepare,
3107 files_transaction_finish,
3108 files_transaction_abort,
fc681463 3109 files_initial_transaction_commit,
e1e33b72 3110
8231527e 3111 files_pack_refs,
284689ba 3112 files_create_symref,
a27dcf89 3113 files_delete_refs,
9b6b40d9 3114 files_rename_ref,
52d59cc6 3115 files_copy_ref,
8231527e 3116
1a769003 3117 files_ref_iterator_begin,
62665823 3118 files_read_raw_ref,
e3688bd6
DT
3119
3120 files_reflog_iterator_begin,
3121 files_for_each_reflog_ent,
3122 files_for_each_reflog_ent_reverse,
3123 files_reflog_exists,
3124 files_create_reflog,
3125 files_delete_reflog,
3126 files_reflog_expire
3dce444f 3127};