Add a place for (not) sharing stuff between worktrees
[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"
fb9c2d27 12#include "../chdir-notify.h"
7bd9bcf3 13
5ac95fee
MH
14/*
15 * This backend uses the following flags in `ref_update::flags` for
16 * internal bookkeeping purposes. Their numerical values must not
91774afc 17 * conflict with REF_NO_DEREF, REF_FORCE_CREATE_REFLOG, REF_HAVE_NEW,
acedcde7 18 * REF_HAVE_OLD, or REF_IS_PRUNING, which are also stored in
5ac95fee
MH
19 * `ref_update::flags`.
20 */
21
22/*
23 * Used as a flag in ref_update::flags when a loose ref is being
91774afc 24 * pruned. This flag must only be used when REF_NO_DEREF is set.
5ac95fee 25 */
acedcde7 26#define REF_IS_PRUNING (1 << 4)
5ac95fee
MH
27
28/*
29 * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken
30 * refs (i.e., because the reference is about to be deleted anyway).
31 */
32#define REF_DELETING (1 << 5)
33
34/*
35 * Used as a flag in ref_update::flags when the lockfile needs to be
36 * committed.
37 */
38#define REF_NEEDS_COMMIT (1 << 6)
39
40/*
41 * Used as a flag in ref_update::flags when we want to log a ref
42 * update but not actually perform it. This is used when a symbolic
43 * ref update is split up.
44 */
45#define REF_LOG_ONLY (1 << 7)
46
47/*
48 * Used as a flag in ref_update::flags when the ref_update was via an
49 * update to HEAD.
50 */
51#define REF_UPDATE_VIA_HEAD (1 << 8)
52
53/*
54 * Used as a flag in ref_update::flags when the loose reference has
55 * been deleted.
56 */
57#define REF_DELETED_LOOSE (1 << 9)
58
7bd9bcf3
MH
59struct ref_lock {
60 char *ref_name;
ee4d8e45 61 struct lock_file lk;
7bd9bcf3
MH
62 struct object_id old_oid;
63};
64
00eebe35
MH
65struct files_ref_store {
66 struct ref_store base;
9e7ec634 67 unsigned int store_flags;
32c597e7 68
f57f37e2
NTND
69 char *gitdir;
70 char *gitcommondir;
33dfb9f3 71
7c22bc8a 72 struct ref_cache *loose;
55c6bc37 73
e0cc8ac8 74 struct ref_store *packed_ref_store;
00eebe35 75};
7bd9bcf3 76
65a0a8e5 77static void clear_loose_ref_cache(struct files_ref_store *refs)
7bd9bcf3
MH
78{
79 if (refs->loose) {
7c22bc8a 80 free_ref_cache(refs->loose);
7bd9bcf3
MH
81 refs->loose = NULL;
82 }
83}
84
a2d5156c
JK
85/*
86 * Create a new submodule ref cache and add it to the internal
87 * set of caches.
88 */
9e7ec634
NTND
89static struct ref_store *files_ref_store_create(const char *gitdir,
90 unsigned int flags)
7bd9bcf3 91{
00eebe35
MH
92 struct files_ref_store *refs = xcalloc(1, sizeof(*refs));
93 struct ref_store *ref_store = (struct ref_store *)refs;
f57f37e2 94 struct strbuf sb = STRBUF_INIT;
7bd9bcf3 95
fbfd0a29 96 base_ref_store_init(ref_store, &refs_be_files);
9e7ec634 97 refs->store_flags = flags;
7bd9bcf3 98
f57f37e2
NTND
99 refs->gitdir = xstrdup(gitdir);
100 get_common_dir_noenv(&sb, gitdir);
101 refs->gitcommondir = strbuf_detach(&sb, NULL);
102 strbuf_addf(&sb, "%s/packed-refs", refs->gitcommondir);
e0d48397
MH
103 refs->packed_ref_store = packed_ref_store_create(sb.buf, flags);
104 strbuf_release(&sb);
7bd9bcf3 105
fb9c2d27
JK
106 chdir_notify_reparent("files-backend $GIT_DIR",
107 &refs->gitdir);
108 chdir_notify_reparent("files-backend $GIT_COMMONDIR",
109 &refs->gitcommondir);
110
00eebe35 111 return ref_store;
a2d5156c 112}
7bd9bcf3 113
32c597e7 114/*
9e7ec634
NTND
115 * Die if refs is not the main ref store. caller is used in any
116 * necessary error messages.
32c597e7
MH
117 */
118static void files_assert_main_repository(struct files_ref_store *refs,
119 const char *caller)
120{
9e7ec634
NTND
121 if (refs->store_flags & REF_STORE_MAIN)
122 return;
123
033abf97 124 BUG("operation %s only allowed for main ref store", caller);
32c597e7
MH
125}
126
a2d5156c 127/*
00eebe35 128 * Downcast ref_store to files_ref_store. Die if ref_store is not a
9e7ec634
NTND
129 * files_ref_store. required_flags is compared with ref_store's
130 * store_flags to ensure the ref_store has all required capabilities.
131 * "caller" is used in any necessary error messages.
a2d5156c 132 */
9e7ec634
NTND
133static struct files_ref_store *files_downcast(struct ref_store *ref_store,
134 unsigned int required_flags,
135 const char *caller)
a2d5156c 136{
32c597e7
MH
137 struct files_ref_store *refs;
138
00eebe35 139 if (ref_store->be != &refs_be_files)
033abf97 140 BUG("ref_store is type \"%s\" not \"files\" in %s",
00eebe35 141 ref_store->be->name, caller);
2eed2780 142
32c597e7
MH
143 refs = (struct files_ref_store *)ref_store;
144
9e7ec634 145 if ((refs->store_flags & required_flags) != required_flags)
033abf97 146 BUG("operation %s requires abilities 0x%x, but only have 0x%x",
9e7ec634 147 caller, required_flags, refs->store_flags);
2eed2780 148
32c597e7 149 return refs;
7bd9bcf3
MH
150}
151
802de3da
NTND
152static void files_reflog_path(struct files_ref_store *refs,
153 struct strbuf *sb,
154 const char *refname)
155{
f57f37e2
NTND
156 switch (ref_type(refname)) {
157 case REF_TYPE_PER_WORKTREE:
158 case REF_TYPE_PSEUDOREF:
159 strbuf_addf(sb, "%s/logs/%s", refs->gitdir, refname);
160 break;
161 case REF_TYPE_NORMAL:
162 strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir, refname);
163 break;
164 default:
033abf97 165 BUG("unknown ref type %d of ref %s",
f57f37e2
NTND
166 ref_type(refname), refname);
167 }
802de3da
NTND
168}
169
19e02f4f
NTND
170static void files_ref_path(struct files_ref_store *refs,
171 struct strbuf *sb,
172 const char *refname)
173{
f57f37e2
NTND
174 switch (ref_type(refname)) {
175 case REF_TYPE_PER_WORKTREE:
176 case REF_TYPE_PSEUDOREF:
177 strbuf_addf(sb, "%s/%s", refs->gitdir, refname);
178 break;
179 case REF_TYPE_NORMAL:
180 strbuf_addf(sb, "%s/%s", refs->gitcommondir, refname);
181 break;
182 default:
033abf97 183 BUG("unknown ref type %d of ref %s",
f57f37e2
NTND
184 ref_type(refname), refname);
185 }
19e02f4f
NTND
186}
187
7bd9bcf3
MH
188/*
189 * Read the loose references from the namespace dirname into dir
190 * (without recursing). dirname must end with '/'. dir must be the
191 * directory entry corresponding to dirname.
192 */
df308759
MH
193static void loose_fill_ref_dir(struct ref_store *ref_store,
194 struct ref_dir *dir, const char *dirname)
7bd9bcf3 195{
df308759
MH
196 struct files_ref_store *refs =
197 files_downcast(ref_store, REF_STORE_READ, "fill_ref_dir");
7bd9bcf3
MH
198 DIR *d;
199 struct dirent *de;
200 int dirnamelen = strlen(dirname);
201 struct strbuf refname;
202 struct strbuf path = STRBUF_INIT;
203 size_t path_baselen;
204
19e02f4f 205 files_ref_path(refs, &path, dirname);
7bd9bcf3
MH
206 path_baselen = path.len;
207
208 d = opendir(path.buf);
209 if (!d) {
210 strbuf_release(&path);
211 return;
212 }
213
214 strbuf_init(&refname, dirnamelen + 257);
215 strbuf_add(&refname, dirname, dirnamelen);
216
217 while ((de = readdir(d)) != NULL) {
4417df8c 218 struct object_id oid;
7bd9bcf3
MH
219 struct stat st;
220 int flag;
221
222 if (de->d_name[0] == '.')
223 continue;
224 if (ends_with(de->d_name, ".lock"))
225 continue;
226 strbuf_addstr(&refname, de->d_name);
227 strbuf_addstr(&path, de->d_name);
228 if (stat(path.buf, &st) < 0) {
229 ; /* silently ignore */
230 } else if (S_ISDIR(st.st_mode)) {
231 strbuf_addch(&refname, '/');
232 add_entry_to_dir(dir,
e00d1a4f 233 create_dir_entry(dir->cache, refname.buf,
7bd9bcf3
MH
234 refname.len, 1));
235 } else {
7d2df051 236 if (!refs_resolve_ref_unsafe(&refs->base,
3c0cb0cb
MH
237 refname.buf,
238 RESOLVE_REF_READING,
49e61479 239 &oid, &flag)) {
4417df8c 240 oidclr(&oid);
7bd9bcf3 241 flag |= REF_ISBROKEN;
4417df8c 242 } else if (is_null_oid(&oid)) {
7bd9bcf3
MH
243 /*
244 * It is so astronomically unlikely
78fb4579 245 * that null_oid is the OID of an
7bd9bcf3
MH
246 * actual object that we consider its
247 * appearance in a loose reference
248 * file to be repo corruption
249 * (probably due to a software bug).
250 */
251 flag |= REF_ISBROKEN;
252 }
253
254 if (check_refname_format(refname.buf,
255 REFNAME_ALLOW_ONELEVEL)) {
256 if (!refname_is_safe(refname.buf))
257 die("loose refname is dangerous: %s", refname.buf);
4417df8c 258 oidclr(&oid);
7bd9bcf3
MH
259 flag |= REF_BAD_NAME | REF_ISBROKEN;
260 }
261 add_entry_to_dir(dir,
c1da06c6 262 create_ref_entry(refname.buf, &oid, flag));
7bd9bcf3
MH
263 }
264 strbuf_setlen(&refname, dirnamelen);
265 strbuf_setlen(&path, path_baselen);
266 }
267 strbuf_release(&refname);
268 strbuf_release(&path);
269 closedir(d);
e3bf2989
MH
270
271 /*
8aff1a9c
NTND
272 * Manually add refs/bisect and refs/worktree, which, being
273 * per-worktree, might not appear in the directory listing for
274 * refs/ in the main repo.
e3bf2989
MH
275 */
276 if (!strcmp(dirname, "refs/")) {
277 int pos = search_ref_dir(dir, "refs/bisect/", 12);
278
279 if (pos < 0) {
280 struct ref_entry *child_entry = create_dir_entry(
281 dir->cache, "refs/bisect/", 12, 1);
282 add_entry_to_dir(dir, child_entry);
283 }
8aff1a9c
NTND
284
285 pos = search_ref_dir(dir, "refs/worktree/", 11);
286
287 if (pos < 0) {
288 struct ref_entry *child_entry = create_dir_entry(
289 dir->cache, "refs/worktree/", 11, 1);
290 add_entry_to_dir(dir, child_entry);
291 }
e3bf2989 292 }
7bd9bcf3
MH
293}
294
a714b19c 295static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs)
7bd9bcf3
MH
296{
297 if (!refs->loose) {
298 /*
299 * Mark the top-level directory complete because we
300 * are about to read the only subdirectory that can
301 * hold references:
302 */
df308759 303 refs->loose = create_ref_cache(&refs->base, loose_fill_ref_dir);
7c22bc8a
MH
304
305 /* We're going to fill the top level ourselves: */
306 refs->loose->root->flag &= ~REF_INCOMPLETE;
307
7bd9bcf3 308 /*
7c22bc8a
MH
309 * Add an incomplete entry for "refs/" (to be filled
310 * lazily):
7bd9bcf3 311 */
7c22bc8a 312 add_entry_to_dir(get_ref_dir(refs->loose->root),
e00d1a4f 313 create_dir_entry(refs->loose, "refs/", 5, 1));
7bd9bcf3 314 }
a714b19c 315 return refs->loose;
7bd9bcf3
MH
316}
317
e1e33b72 318static int files_read_raw_ref(struct ref_store *ref_store,
99afe91a 319 const char *refname, struct object_id *oid,
e1e33b72 320 struct strbuf *referent, unsigned int *type)
7bd9bcf3 321{
4308651c 322 struct files_ref_store *refs =
9e7ec634 323 files_downcast(ref_store, REF_STORE_READ, "read_raw_ref");
42a38cf7
MH
324 struct strbuf sb_contents = STRBUF_INIT;
325 struct strbuf sb_path = STRBUF_INIT;
7048653a
DT
326 const char *path;
327 const char *buf;
99afe91a 328 const char *p;
7048653a
DT
329 struct stat st;
330 int fd;
42a38cf7
MH
331 int ret = -1;
332 int save_errno;
e8c42cb9 333 int remaining_retries = 3;
7bd9bcf3 334
fa96ea1b 335 *type = 0;
42a38cf7 336 strbuf_reset(&sb_path);
34c7ad8f 337
19e02f4f 338 files_ref_path(refs, &sb_path, refname);
34c7ad8f 339
42a38cf7 340 path = sb_path.buf;
7bd9bcf3 341
7048653a
DT
342stat_ref:
343 /*
344 * We might have to loop back here to avoid a race
345 * condition: first we lstat() the file, then we try
346 * to read it as a link or as a file. But if somebody
347 * changes the type of the file (file <-> directory
348 * <-> symlink) between the lstat() and reading, then
349 * we don't want to report that as an error but rather
350 * try again starting with the lstat().
e8c42cb9
JK
351 *
352 * We'll keep a count of the retries, though, just to avoid
353 * any confusing situation sending us into an infinite loop.
7048653a 354 */
7bd9bcf3 355
e8c42cb9
JK
356 if (remaining_retries-- <= 0)
357 goto out;
358
7048653a
DT
359 if (lstat(path, &st) < 0) {
360 if (errno != ENOENT)
42a38cf7 361 goto out;
e0cc8ac8 362 if (refs_read_raw_ref(refs->packed_ref_store, refname,
99afe91a 363 oid, referent, type)) {
7048653a 364 errno = ENOENT;
42a38cf7 365 goto out;
7bd9bcf3 366 }
42a38cf7
MH
367 ret = 0;
368 goto out;
7bd9bcf3 369 }
7bd9bcf3 370
7048653a
DT
371 /* Follow "normalized" - ie "refs/.." symlinks by hand */
372 if (S_ISLNK(st.st_mode)) {
42a38cf7 373 strbuf_reset(&sb_contents);
765b496d 374 if (strbuf_readlink(&sb_contents, path, st.st_size) < 0) {
7048653a 375 if (errno == ENOENT || errno == EINVAL)
7bd9bcf3
MH
376 /* inconsistent with lstat; retry */
377 goto stat_ref;
378 else
42a38cf7 379 goto out;
7bd9bcf3 380 }
42a38cf7
MH
381 if (starts_with(sb_contents.buf, "refs/") &&
382 !check_refname_format(sb_contents.buf, 0)) {
92b38093 383 strbuf_swap(&sb_contents, referent);
3a0b6b9a 384 *type |= REF_ISSYMREF;
42a38cf7
MH
385 ret = 0;
386 goto out;
7bd9bcf3 387 }
3f7bd767
JK
388 /*
389 * It doesn't look like a refname; fall through to just
390 * treating it like a non-symlink, and reading whatever it
391 * points to.
392 */
7048653a 393 }
7bd9bcf3 394
7048653a
DT
395 /* Is it a directory? */
396 if (S_ISDIR(st.st_mode)) {
e167a567
MH
397 /*
398 * Even though there is a directory where the loose
399 * ref is supposed to be, there could still be a
400 * packed ref:
401 */
e0cc8ac8 402 if (refs_read_raw_ref(refs->packed_ref_store, refname,
99afe91a 403 oid, referent, type)) {
e167a567
MH
404 errno = EISDIR;
405 goto out;
406 }
407 ret = 0;
42a38cf7 408 goto out;
7048653a
DT
409 }
410
411 /*
412 * Anything else, just open it and try to use it as
413 * a ref
414 */
415 fd = open(path, O_RDONLY);
416 if (fd < 0) {
3f7bd767 417 if (errno == ENOENT && !S_ISLNK(st.st_mode))
7048653a
DT
418 /* inconsistent with lstat; retry */
419 goto stat_ref;
420 else
42a38cf7 421 goto out;
7048653a 422 }
42a38cf7
MH
423 strbuf_reset(&sb_contents);
424 if (strbuf_read(&sb_contents, fd, 256) < 0) {
7048653a
DT
425 int save_errno = errno;
426 close(fd);
427 errno = save_errno;
42a38cf7 428 goto out;
7048653a
DT
429 }
430 close(fd);
42a38cf7
MH
431 strbuf_rtrim(&sb_contents);
432 buf = sb_contents.buf;
7048653a
DT
433 if (starts_with(buf, "ref:")) {
434 buf += 4;
7bd9bcf3
MH
435 while (isspace(*buf))
436 buf++;
7048653a 437
92b38093
MH
438 strbuf_reset(referent);
439 strbuf_addstr(referent, buf);
3a0b6b9a 440 *type |= REF_ISSYMREF;
42a38cf7
MH
441 ret = 0;
442 goto out;
7bd9bcf3 443 }
7bd9bcf3 444
7048653a
DT
445 /*
446 * Please note that FETCH_HEAD has additional
447 * data after the sha.
448 */
99afe91a 449 if (parse_oid_hex(buf, oid, &p) ||
450 (*p != '\0' && !isspace(*p))) {
3a0b6b9a 451 *type |= REF_ISBROKEN;
7048653a 452 errno = EINVAL;
42a38cf7 453 goto out;
7048653a
DT
454 }
455
42a38cf7 456 ret = 0;
7bd9bcf3 457
42a38cf7
MH
458out:
459 save_errno = errno;
7bd9bcf3
MH
460 strbuf_release(&sb_path);
461 strbuf_release(&sb_contents);
42a38cf7 462 errno = save_errno;
7bd9bcf3
MH
463 return ret;
464}
465
8415d247
MH
466static void unlock_ref(struct ref_lock *lock)
467{
ee4d8e45 468 rollback_lock_file(&lock->lk);
8415d247 469 free(lock->ref_name);
8415d247
MH
470 free(lock);
471}
472
92b1551b
MH
473/*
474 * Lock refname, without following symrefs, and set *lock_p to point
475 * at a newly-allocated lock object. Fill in lock->old_oid, referent,
476 * and type similarly to read_raw_ref().
477 *
478 * The caller must verify that refname is a "safe" reference name (in
479 * the sense of refname_is_safe()) before calling this function.
480 *
481 * If the reference doesn't already exist, verify that refname doesn't
482 * have a D/F conflict with any existing references. extras and skip
524a9fdb 483 * are passed to refs_verify_refname_available() for this check.
92b1551b
MH
484 *
485 * If mustexist is not set and the reference is not found or is
78fb4579 486 * broken, lock the reference anyway but clear old_oid.
92b1551b
MH
487 *
488 * Return 0 on success. On failure, write an error message to err and
489 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.
490 *
491 * Implementation note: This function is basically
492 *
493 * lock reference
494 * read_raw_ref()
495 *
496 * but it includes a lot more code to
497 * - Deal with possible races with other processes
524a9fdb 498 * - Avoid calling refs_verify_refname_available() when it can be
92b1551b
MH
499 * avoided, namely if we were successfully able to read the ref
500 * - Generate informative error messages in the case of failure
501 */
f7b0a987
MH
502static int lock_raw_ref(struct files_ref_store *refs,
503 const char *refname, int mustexist,
92b1551b
MH
504 const struct string_list *extras,
505 const struct string_list *skip,
506 struct ref_lock **lock_p,
507 struct strbuf *referent,
508 unsigned int *type,
509 struct strbuf *err)
510{
511 struct ref_lock *lock;
512 struct strbuf ref_file = STRBUF_INIT;
513 int attempts_remaining = 3;
514 int ret = TRANSACTION_GENERIC_ERROR;
515
516 assert(err);
32c597e7 517 files_assert_main_repository(refs, "lock_raw_ref");
f7b0a987 518
92b1551b
MH
519 *type = 0;
520
521 /* First lock the file so it can't change out from under us. */
522
523 *lock_p = lock = xcalloc(1, sizeof(*lock));
524
525 lock->ref_name = xstrdup(refname);
19e02f4f 526 files_ref_path(refs, &ref_file, refname);
92b1551b
MH
527
528retry:
529 switch (safe_create_leading_directories(ref_file.buf)) {
530 case SCLD_OK:
531 break; /* success */
532 case SCLD_EXISTS:
533 /*
534 * Suppose refname is "refs/foo/bar". We just failed
535 * to create the containing directory, "refs/foo",
536 * because there was a non-directory in the way. This
537 * indicates a D/F conflict, probably because of
538 * another reference such as "refs/foo". There is no
539 * reason to expect this error to be transitory.
540 */
7d2df051
NTND
541 if (refs_verify_refname_available(&refs->base, refname,
542 extras, skip, err)) {
92b1551b
MH
543 if (mustexist) {
544 /*
545 * To the user the relevant error is
546 * that the "mustexist" reference is
547 * missing:
548 */
549 strbuf_reset(err);
550 strbuf_addf(err, "unable to resolve reference '%s'",
551 refname);
552 } else {
553 /*
554 * The error message set by
524a9fdb
MH
555 * refs_verify_refname_available() is
556 * OK.
92b1551b
MH
557 */
558 ret = TRANSACTION_NAME_CONFLICT;
559 }
560 } else {
561 /*
562 * The file that is in the way isn't a loose
563 * reference. Report it as a low-level
564 * failure.
565 */
566 strbuf_addf(err, "unable to create lock file %s.lock; "
567 "non-directory in the way",
568 ref_file.buf);
569 }
570 goto error_return;
571 case SCLD_VANISHED:
572 /* Maybe another process was tidying up. Try again. */
573 if (--attempts_remaining > 0)
574 goto retry;
575 /* fall through */
576 default:
577 strbuf_addf(err, "unable to create directory for %s",
578 ref_file.buf);
579 goto error_return;
580 }
581
4ff0f01c 582 if (hold_lock_file_for_update_timeout(
ee4d8e45 583 &lock->lk, ref_file.buf, LOCK_NO_DEREF,
4ff0f01c 584 get_files_ref_lock_timeout_ms()) < 0) {
92b1551b
MH
585 if (errno == ENOENT && --attempts_remaining > 0) {
586 /*
587 * Maybe somebody just deleted one of the
588 * directories leading to ref_file. Try
589 * again:
590 */
591 goto retry;
592 } else {
593 unable_to_lock_message(ref_file.buf, errno, err);
594 goto error_return;
595 }
596 }
597
598 /*
599 * Now we hold the lock and can read the reference without
600 * fear that its value will change.
601 */
602
f7b0a987 603 if (files_read_raw_ref(&refs->base, refname,
99afe91a 604 &lock->old_oid, referent, type)) {
92b1551b
MH
605 if (errno == ENOENT) {
606 if (mustexist) {
607 /* Garden variety missing reference. */
608 strbuf_addf(err, "unable to resolve reference '%s'",
609 refname);
610 goto error_return;
611 } else {
612 /*
613 * Reference is missing, but that's OK. We
614 * know that there is not a conflict with
615 * another loose reference because
616 * (supposing that we are trying to lock
617 * reference "refs/foo/bar"):
618 *
619 * - We were successfully able to create
620 * the lockfile refs/foo/bar.lock, so we
621 * know there cannot be a loose reference
622 * named "refs/foo".
623 *
624 * - We got ENOENT and not EISDIR, so we
625 * know that there cannot be a loose
626 * reference named "refs/foo/bar/baz".
627 */
628 }
629 } else if (errno == EISDIR) {
630 /*
631 * There is a directory in the way. It might have
632 * contained references that have been deleted. If
633 * we don't require that the reference already
634 * exists, try to remove the directory so that it
635 * doesn't cause trouble when we want to rename the
636 * lockfile into place later.
637 */
638 if (mustexist) {
639 /* Garden variety missing reference. */
640 strbuf_addf(err, "unable to resolve reference '%s'",
641 refname);
642 goto error_return;
643 } else if (remove_dir_recursively(&ref_file,
644 REMOVE_DIR_EMPTY_ONLY)) {
b05855b5
MH
645 if (refs_verify_refname_available(
646 &refs->base, refname,
647 extras, skip, err)) {
92b1551b
MH
648 /*
649 * The error message set by
650 * verify_refname_available() is OK.
651 */
652 ret = TRANSACTION_NAME_CONFLICT;
653 goto error_return;
654 } else {
655 /*
656 * We can't delete the directory,
657 * but we also don't know of any
658 * references that it should
659 * contain.
660 */
661 strbuf_addf(err, "there is a non-empty directory '%s' "
662 "blocking reference '%s'",
663 ref_file.buf, refname);
664 goto error_return;
665 }
666 }
667 } else if (errno == EINVAL && (*type & REF_ISBROKEN)) {
668 strbuf_addf(err, "unable to resolve reference '%s': "
669 "reference broken", refname);
670 goto error_return;
671 } else {
672 strbuf_addf(err, "unable to resolve reference '%s': %s",
673 refname, strerror(errno));
674 goto error_return;
675 }
676
677 /*
678 * If the ref did not exist and we are creating it,
8ec617c8
MH
679 * make sure there is no existing packed ref that
680 * conflicts with refname:
92b1551b 681 */
524a9fdb 682 if (refs_verify_refname_available(
8ec617c8 683 refs->packed_ref_store, refname,
524a9fdb 684 extras, skip, err))
92b1551b 685 goto error_return;
92b1551b
MH
686 }
687
688 ret = 0;
689 goto out;
690
691error_return:
692 unlock_ref(lock);
693 *lock_p = NULL;
694
695out:
696 strbuf_release(&ref_file);
697 return ret;
698}
699
3bc581b9
MH
700struct files_ref_iterator {
701 struct ref_iterator base;
702
3bc581b9
MH
703 struct ref_iterator *iter0;
704 unsigned int flags;
705};
7bd9bcf3 706
3bc581b9
MH
707static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)
708{
709 struct files_ref_iterator *iter =
710 (struct files_ref_iterator *)ref_iterator;
711 int ok;
7bd9bcf3 712
3bc581b9 713 while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
0c09ec07
DT
714 if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&
715 ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)
716 continue;
717
3bc581b9
MH
718 if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
719 !ref_resolves_to_object(iter->iter0->refname,
720 iter->iter0->oid,
721 iter->iter0->flags))
722 continue;
723
724 iter->base.refname = iter->iter0->refname;
725 iter->base.oid = iter->iter0->oid;
726 iter->base.flags = iter->iter0->flags;
727 return ITER_OK;
7bd9bcf3
MH
728 }
729
3bc581b9
MH
730 iter->iter0 = NULL;
731 if (ref_iterator_abort(ref_iterator) != ITER_DONE)
732 ok = ITER_ERROR;
733
734 return ok;
7bd9bcf3
MH
735}
736
3bc581b9
MH
737static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,
738 struct object_id *peeled)
7bd9bcf3 739{
3bc581b9
MH
740 struct files_ref_iterator *iter =
741 (struct files_ref_iterator *)ref_iterator;
93770590 742
3bc581b9
MH
743 return ref_iterator_peel(iter->iter0, peeled);
744}
745
746static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)
747{
748 struct files_ref_iterator *iter =
749 (struct files_ref_iterator *)ref_iterator;
750 int ok = ITER_DONE;
751
752 if (iter->iter0)
753 ok = ref_iterator_abort(iter->iter0);
754
3bc581b9
MH
755 base_ref_iterator_free(ref_iterator);
756 return ok;
757}
758
759static struct ref_iterator_vtable files_ref_iterator_vtable = {
760 files_ref_iterator_advance,
761 files_ref_iterator_peel,
762 files_ref_iterator_abort
763};
764
1a769003 765static struct ref_iterator *files_ref_iterator_begin(
37b6f6d5 766 struct ref_store *ref_store,
3bc581b9
MH
767 const char *prefix, unsigned int flags)
768{
9e7ec634 769 struct files_ref_store *refs;
8738a8a4 770 struct ref_iterator *loose_iter, *packed_iter, *overlay_iter;
3bc581b9
MH
771 struct files_ref_iterator *iter;
772 struct ref_iterator *ref_iterator;
0a0865b8 773 unsigned int required_flags = REF_STORE_READ;
3bc581b9 774
0a0865b8
MH
775 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN))
776 required_flags |= REF_STORE_ODB;
3bc581b9 777
0a0865b8 778 refs = files_downcast(ref_store, required_flags, "ref_iterator_begin");
9e7ec634 779
3bc581b9
MH
780 /*
781 * We must make sure that all loose refs are read before
782 * accessing the packed-refs file; this avoids a race
783 * condition if loose refs are migrated to the packed-refs
784 * file by a simultaneous process, but our in-memory view is
785 * from before the migration. We ensure this as follows:
059ae35a
MH
786 * First, we call start the loose refs iteration with its
787 * `prime_ref` argument set to true. This causes the loose
788 * references in the subtree to be pre-read into the cache.
789 * (If they've already been read, that's OK; we only need to
790 * guarantee that they're read before the packed refs, not
791 * *how much* before.) After that, we call
38b86e81
MH
792 * packed_ref_iterator_begin(), which internally checks
793 * whether the packed-ref cache is up to date with what is on
794 * disk, and re-reads it if not.
3bc581b9
MH
795 */
796
059ae35a
MH
797 loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs),
798 prefix, 1);
3bc581b9 799
38b86e81
MH
800 /*
801 * The packed-refs file might contain broken references, for
802 * example an old version of a reference that points at an
803 * object that has since been garbage-collected. This is OK as
804 * long as there is a corresponding loose reference that
805 * overrides it, and we don't want to emit an error message in
806 * this case. So ask the packed_ref_store for all of its
807 * references, and (if needed) do our own check for broken
808 * ones in files_ref_iterator_advance(), after we have merged
809 * the packed and loose references.
810 */
e0cc8ac8
MH
811 packed_iter = refs_ref_iterator_begin(
812 refs->packed_ref_store, prefix, 0,
38b86e81 813 DO_FOR_EACH_INCLUDE_BROKEN);
3bc581b9 814
8738a8a4
MH
815 overlay_iter = overlay_ref_iterator_begin(loose_iter, packed_iter);
816
817 iter = xcalloc(1, sizeof(*iter));
818 ref_iterator = &iter->base;
819 base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable,
820 overlay_iter->ordered);
821 iter->iter0 = overlay_iter;
3bc581b9
MH
822 iter->flags = flags;
823
824 return ref_iterator;
7bd9bcf3
MH
825}
826
7bd9bcf3 827/*
4f01e508 828 * Verify that the reference locked by lock has the value old_oid
829 * (unless it is NULL). Fail if the reference doesn't exist and
830 * mustexist is set. Return 0 on success. On error, write an error
831 * message to err, set errno, and return a negative value.
7bd9bcf3 832 */
2f40e954 833static int verify_lock(struct ref_store *ref_store, struct ref_lock *lock,
4f01e508 834 const struct object_id *old_oid, int mustexist,
7bd9bcf3
MH
835 struct strbuf *err)
836{
837 assert(err);
838
2f40e954
NTND
839 if (refs_read_ref_full(ref_store, lock->ref_name,
840 mustexist ? RESOLVE_REF_READING : 0,
34c290a6 841 &lock->old_oid, NULL)) {
4f01e508 842 if (old_oid) {
6294dcb4 843 int save_errno = errno;
0568c8e9 844 strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);
6294dcb4
JK
845 errno = save_errno;
846 return -1;
847 } else {
c368dde9 848 oidclr(&lock->old_oid);
6294dcb4
JK
849 return 0;
850 }
7bd9bcf3 851 }
9001dc2a 852 if (old_oid && !oideq(&lock->old_oid, old_oid)) {
0568c8e9 853 strbuf_addf(err, "ref '%s' is at %s but expected %s",
7bd9bcf3 854 lock->ref_name,
c368dde9 855 oid_to_hex(&lock->old_oid),
4f01e508 856 oid_to_hex(old_oid));
7bd9bcf3
MH
857 errno = EBUSY;
858 return -1;
859 }
860 return 0;
861}
862
863static int remove_empty_directories(struct strbuf *path)
864{
865 /*
866 * we want to create a file but there is a directory there;
867 * if that is an empty directory (or a directory that contains
868 * only empty directories), remove them.
869 */
870 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);
871}
872
3b5d3c98
MH
873static int create_reflock(const char *path, void *cb)
874{
875 struct lock_file *lk = cb;
876
4ff0f01c
MH
877 return hold_lock_file_for_update_timeout(
878 lk, path, LOCK_NO_DEREF,
879 get_files_ref_lock_timeout_ms()) < 0 ? -1 : 0;
3b5d3c98
MH
880}
881
7bd9bcf3
MH
882/*
883 * Locks a ref returning the lock on success and NULL on failure.
884 * On failure errno is set to something meaningful.
885 */
4f01e508 886static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
887 const char *refname,
888 const struct object_id *old_oid,
889 const struct string_list *extras,
890 const struct string_list *skip,
891 unsigned int flags, int *type,
892 struct strbuf *err)
7bd9bcf3
MH
893{
894 struct strbuf ref_file = STRBUF_INIT;
7bd9bcf3
MH
895 struct ref_lock *lock;
896 int last_errno = 0;
4f01e508 897 int mustexist = (old_oid && !is_null_oid(old_oid));
7a418f3a 898 int resolve_flags = RESOLVE_REF_NO_RECURSE;
7a418f3a 899 int resolved;
7bd9bcf3 900
4f01e508 901 files_assert_main_repository(refs, "lock_ref_oid_basic");
7bd9bcf3
MH
902 assert(err);
903
904 lock = xcalloc(1, sizeof(struct ref_lock));
905
906 if (mustexist)
907 resolve_flags |= RESOLVE_REF_READING;
2859dcd4 908 if (flags & REF_DELETING)
7bd9bcf3 909 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
7bd9bcf3 910
19e02f4f 911 files_ref_path(refs, &ref_file, refname);
2f40e954
NTND
912 resolved = !!refs_resolve_ref_unsafe(&refs->base,
913 refname, resolve_flags,
49e61479 914 &lock->old_oid, type);
7a418f3a 915 if (!resolved && errno == EISDIR) {
7bd9bcf3
MH
916 /*
917 * we are trying to lock foo but we used to
918 * have foo/bar which now does not exist;
919 * it is normal for the empty directory 'foo'
920 * to remain.
921 */
7a418f3a 922 if (remove_empty_directories(&ref_file)) {
7bd9bcf3 923 last_errno = errno;
b05855b5
MH
924 if (!refs_verify_refname_available(
925 &refs->base,
926 refname, extras, skip, err))
7bd9bcf3 927 strbuf_addf(err, "there are still refs under '%s'",
7a418f3a 928 refname);
7bd9bcf3
MH
929 goto error_return;
930 }
2f40e954
NTND
931 resolved = !!refs_resolve_ref_unsafe(&refs->base,
932 refname, resolve_flags,
49e61479 933 &lock->old_oid, type);
7bd9bcf3 934 }
7a418f3a 935 if (!resolved) {
7bd9bcf3
MH
936 last_errno = errno;
937 if (last_errno != ENOTDIR ||
b05855b5
MH
938 !refs_verify_refname_available(&refs->base, refname,
939 extras, skip, err))
0568c8e9 940 strbuf_addf(err, "unable to resolve reference '%s': %s",
7a418f3a 941 refname, strerror(last_errno));
7bd9bcf3
MH
942
943 goto error_return;
944 }
2859dcd4 945
7bd9bcf3
MH
946 /*
947 * If the ref did not exist and we are creating it, make sure
948 * there is no existing packed ref whose name begins with our
949 * refname, nor a packed ref whose name is a proper prefix of
950 * our refname.
951 */
952 if (is_null_oid(&lock->old_oid) &&
8ec617c8 953 refs_verify_refname_available(refs->packed_ref_store, refname,
524a9fdb 954 extras, skip, err)) {
7bd9bcf3
MH
955 last_errno = ENOTDIR;
956 goto error_return;
957 }
958
7bd9bcf3 959 lock->ref_name = xstrdup(refname);
7bd9bcf3 960
ee4d8e45 961 if (raceproof_create_file(ref_file.buf, create_reflock, &lock->lk)) {
7bd9bcf3 962 last_errno = errno;
3b5d3c98 963 unable_to_lock_message(ref_file.buf, errno, err);
7bd9bcf3
MH
964 goto error_return;
965 }
966
4f01e508 967 if (verify_lock(&refs->base, lock, old_oid, mustexist, err)) {
7bd9bcf3
MH
968 last_errno = errno;
969 goto error_return;
970 }
971 goto out;
972
973 error_return:
974 unlock_ref(lock);
975 lock = NULL;
976
977 out:
978 strbuf_release(&ref_file);
7bd9bcf3
MH
979 errno = last_errno;
980 return lock;
981}
982
7bd9bcf3
MH
983struct ref_to_prune {
984 struct ref_to_prune *next;
49e99588 985 struct object_id oid;
7bd9bcf3
MH
986 char name[FLEX_ARRAY];
987};
988
a8f0db2d
MH
989enum {
990 REMOVE_EMPTY_PARENTS_REF = 0x01,
991 REMOVE_EMPTY_PARENTS_REFLOG = 0x02
992};
993
7bd9bcf3 994/*
a8f0db2d
MH
995 * Remove empty parent directories associated with the specified
996 * reference and/or its reflog, but spare [logs/]refs/ and immediate
997 * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or
998 * REMOVE_EMPTY_PARENTS_REFLOG.
7bd9bcf3 999 */
802de3da
NTND
1000static void try_remove_empty_parents(struct files_ref_store *refs,
1001 const char *refname,
1002 unsigned int flags)
7bd9bcf3 1003{
8bdaecb4 1004 struct strbuf buf = STRBUF_INIT;
e9dcc305 1005 struct strbuf sb = STRBUF_INIT;
7bd9bcf3
MH
1006 char *p, *q;
1007 int i;
8bdaecb4
MH
1008
1009 strbuf_addstr(&buf, refname);
1010 p = buf.buf;
7bd9bcf3
MH
1011 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
1012 while (*p && *p != '/')
1013 p++;
1014 /* tolerate duplicate slashes; see check_refname_format() */
1015 while (*p == '/')
1016 p++;
1017 }
8bdaecb4 1018 q = buf.buf + buf.len;
a8f0db2d 1019 while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {
7bd9bcf3
MH
1020 while (q > p && *q != '/')
1021 q--;
1022 while (q > p && *(q-1) == '/')
1023 q--;
1024 if (q == p)
1025 break;
8bdaecb4 1026 strbuf_setlen(&buf, q - buf.buf);
e9dcc305
NTND
1027
1028 strbuf_reset(&sb);
19e02f4f 1029 files_ref_path(refs, &sb, buf.buf);
e9dcc305 1030 if ((flags & REMOVE_EMPTY_PARENTS_REF) && rmdir(sb.buf))
a8f0db2d 1031 flags &= ~REMOVE_EMPTY_PARENTS_REF;
e9dcc305
NTND
1032
1033 strbuf_reset(&sb);
802de3da 1034 files_reflog_path(refs, &sb, buf.buf);
e9dcc305 1035 if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) && rmdir(sb.buf))
a8f0db2d 1036 flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;
7bd9bcf3 1037 }
8bdaecb4 1038 strbuf_release(&buf);
e9dcc305 1039 strbuf_release(&sb);
7bd9bcf3
MH
1040}
1041
1042/* make sure nobody touched the ref, and unlink */
2f40e954 1043static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r)
7bd9bcf3
MH
1044{
1045 struct ref_transaction *transaction;
1046 struct strbuf err = STRBUF_INIT;
b00f3cfa 1047 int ret = -1;
7bd9bcf3
MH
1048
1049 if (check_refname_format(r->name, 0))
1050 return;
1051
2f40e954 1052 transaction = ref_store_transaction_begin(&refs->base, &err);
b00f3cfa
MH
1053 if (!transaction)
1054 goto cleanup;
1055 ref_transaction_add_update(
1056 transaction, r->name,
acedcde7 1057 REF_NO_DEREF | REF_HAVE_NEW | REF_HAVE_OLD | REF_IS_PRUNING,
b00f3cfa
MH
1058 &null_oid, &r->oid, NULL);
1059 if (ref_transaction_commit(transaction, &err))
1060 goto cleanup;
1061
1062 ret = 0;
1063
1064cleanup:
1065 if (ret)
7bd9bcf3 1066 error("%s", err.buf);
7bd9bcf3 1067 strbuf_release(&err);
b00f3cfa
MH
1068 ref_transaction_free(transaction);
1069 return;
7bd9bcf3
MH
1070}
1071
22b09cdf
MH
1072/*
1073 * Prune the loose versions of the references in the linked list
1074 * `*refs_to_prune`, freeing the entries in the list as we go.
1075 */
1076static void prune_refs(struct files_ref_store *refs, struct ref_to_prune **refs_to_prune)
7bd9bcf3 1077{
22b09cdf
MH
1078 while (*refs_to_prune) {
1079 struct ref_to_prune *r = *refs_to_prune;
1080 *refs_to_prune = r->next;
2f40e954 1081 prune_ref(refs, r);
22b09cdf 1082 free(r);
7bd9bcf3
MH
1083 }
1084}
1085
531cc4a5
MH
1086/*
1087 * Return true if the specified reference should be packed.
1088 */
1089static int should_pack_ref(const char *refname,
1090 const struct object_id *oid, unsigned int ref_flags,
1091 unsigned int pack_flags)
1092{
1093 /* Do not pack per-worktree refs: */
1094 if (ref_type(refname) != REF_TYPE_NORMAL)
1095 return 0;
1096
1097 /* Do not pack non-tags unless PACK_REFS_ALL is set: */
1098 if (!(pack_flags & PACK_REFS_ALL) && !starts_with(refname, "refs/tags/"))
1099 return 0;
1100
1101 /* Do not pack symbolic refs: */
1102 if (ref_flags & REF_ISSYMREF)
1103 return 0;
1104
1105 /* Do not pack broken refs: */
1106 if (!ref_resolves_to_object(refname, oid, ref_flags))
1107 return 0;
1108
1109 return 1;
1110}
1111
8231527e 1112static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)
7bd9bcf3 1113{
00eebe35 1114 struct files_ref_store *refs =
9e7ec634
NTND
1115 files_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB,
1116 "pack_refs");
50c2d855 1117 struct ref_iterator *iter;
50c2d855
MH
1118 int ok;
1119 struct ref_to_prune *refs_to_prune = NULL;
3478983b 1120 struct strbuf err = STRBUF_INIT;
27d03d04
MH
1121 struct ref_transaction *transaction;
1122
1123 transaction = ref_store_transaction_begin(refs->packed_ref_store, &err);
1124 if (!transaction)
1125 return -1;
7bd9bcf3 1126
c8bed835 1127 packed_refs_lock(refs->packed_ref_store, LOCK_DIE_ON_ERROR, &err);
50c2d855
MH
1128
1129 iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), NULL, 0);
1130 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1131 /*
1132 * If the loose reference can be packed, add an entry
1133 * in the packed ref cache. If the reference should be
1134 * pruned, also add it to refs_to_prune.
1135 */
531cc4a5
MH
1136 if (!should_pack_ref(iter->refname, iter->oid, iter->flags,
1137 flags))
50c2d855
MH
1138 continue;
1139
1140 /*
27d03d04
MH
1141 * Add a reference creation for this reference to the
1142 * packed-refs transaction:
50c2d855 1143 */
27d03d04 1144 if (ref_transaction_update(transaction, iter->refname,
89f3bbdd 1145 iter->oid, NULL,
91774afc 1146 REF_NO_DEREF, NULL, &err))
27d03d04
MH
1147 die("failure preparing to create packed reference %s: %s",
1148 iter->refname, err.buf);
50c2d855
MH
1149
1150 /* Schedule the loose reference for pruning if requested. */
1151 if ((flags & PACK_REFS_PRUNE)) {
1152 struct ref_to_prune *n;
1153 FLEX_ALLOC_STR(n, name, iter->refname);
49e99588 1154 oidcpy(&n->oid, iter->oid);
50c2d855
MH
1155 n->next = refs_to_prune;
1156 refs_to_prune = n;
1157 }
1158 }
1159 if (ok != ITER_DONE)
1160 die("error while iterating over references");
7bd9bcf3 1161
27d03d04
MH
1162 if (ref_transaction_commit(transaction, &err))
1163 die("unable to write new packed-refs: %s", err.buf);
1164
1165 ref_transaction_free(transaction);
1166
42c7f7ff 1167 packed_refs_unlock(refs->packed_ref_store);
7bd9bcf3 1168
22b09cdf 1169 prune_refs(refs, &refs_to_prune);
3478983b 1170 strbuf_release(&err);
7bd9bcf3
MH
1171 return 0;
1172}
1173
64da4199 1174static int files_delete_refs(struct ref_store *ref_store, const char *msg,
a27dcf89 1175 struct string_list *refnames, unsigned int flags)
7bd9bcf3 1176{
0a95ac5f 1177 struct files_ref_store *refs =
9e7ec634 1178 files_downcast(ref_store, REF_STORE_WRITE, "delete_refs");
7bd9bcf3
MH
1179 struct strbuf err = STRBUF_INIT;
1180 int i, result = 0;
1181
1182 if (!refnames->nr)
1183 return 0;
1184
e5cc7d7d
MH
1185 if (packed_refs_lock(refs->packed_ref_store, 0, &err))
1186 goto error;
7bd9bcf3 1187
2fb330ca 1188 if (refs_delete_refs(refs->packed_ref_store, msg, refnames, flags)) {
e5cc7d7d
MH
1189 packed_refs_unlock(refs->packed_ref_store);
1190 goto error;
7bd9bcf3
MH
1191 }
1192
e5cc7d7d
MH
1193 packed_refs_unlock(refs->packed_ref_store);
1194
7bd9bcf3
MH
1195 for (i = 0; i < refnames->nr; i++) {
1196 const char *refname = refnames->items[i].string;
1197
64da4199 1198 if (refs_delete_ref(&refs->base, msg, refname, NULL, flags))
7bd9bcf3
MH
1199 result |= error(_("could not remove reference %s"), refname);
1200 }
1201
7bd9bcf3
MH
1202 strbuf_release(&err);
1203 return result;
e5cc7d7d
MH
1204
1205error:
1206 /*
1207 * If we failed to rewrite the packed-refs file, then it is
1208 * unsafe to try to remove loose refs, because doing so might
1209 * expose an obsolete packed value for a reference that might
1210 * even point at an object that has been garbage collected.
1211 */
1212 if (refnames->nr == 1)
1213 error(_("could not delete reference %s: %s"),
1214 refnames->items[0].string, err.buf);
1215 else
1216 error(_("could not delete references: %s"), err.buf);
1217
1218 strbuf_release(&err);
1219 return -1;
7bd9bcf3
MH
1220}
1221
1222/*
1223 * People using contrib's git-new-workdir have .git/logs/refs ->
1224 * /some/other/path/.git/logs/refs, and that may live on another device.
1225 *
1226 * IOW, to avoid cross device rename errors, the temporary renamed log must
1227 * live into logs/refs.
1228 */
a5c1efd6 1229#define TMP_RENAMED_LOG "refs/.tmp-renamed-log"
7bd9bcf3 1230
e9dcc305
NTND
1231struct rename_cb {
1232 const char *tmp_renamed_log;
1233 int true_errno;
1234};
1235
1236static int rename_tmp_log_callback(const char *path, void *cb_data)
7bd9bcf3 1237{
e9dcc305 1238 struct rename_cb *cb = cb_data;
7bd9bcf3 1239
e9dcc305 1240 if (rename(cb->tmp_renamed_log, path)) {
6a7f3631
MH
1241 /*
1242 * rename(a, b) when b is an existing directory ought
1243 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.
1244 * Sheesh. Record the true errno for error reporting,
1245 * but report EISDIR to raceproof_create_file() so
1246 * that it knows to retry.
1247 */
e9dcc305 1248 cb->true_errno = errno;
6a7f3631
MH
1249 if (errno == ENOTDIR)
1250 errno = EISDIR;
1251 return -1;
1252 } else {
1253 return 0;
7bd9bcf3 1254 }
6a7f3631 1255}
7bd9bcf3 1256
802de3da 1257static int rename_tmp_log(struct files_ref_store *refs, const char *newrefname)
6a7f3631 1258{
e9dcc305
NTND
1259 struct strbuf path = STRBUF_INIT;
1260 struct strbuf tmp = STRBUF_INIT;
1261 struct rename_cb cb;
1262 int ret;
6a7f3631 1263
802de3da
NTND
1264 files_reflog_path(refs, &path, newrefname);
1265 files_reflog_path(refs, &tmp, TMP_RENAMED_LOG);
e9dcc305
NTND
1266 cb.tmp_renamed_log = tmp.buf;
1267 ret = raceproof_create_file(path.buf, rename_tmp_log_callback, &cb);
6a7f3631
MH
1268 if (ret) {
1269 if (errno == EISDIR)
e9dcc305 1270 error("directory not empty: %s", path.buf);
6a7f3631 1271 else
990c98d2 1272 error("unable to move logfile %s to %s: %s",
e9dcc305
NTND
1273 tmp.buf, path.buf,
1274 strerror(cb.true_errno));
7bd9bcf3 1275 }
6a7f3631 1276
e9dcc305
NTND
1277 strbuf_release(&path);
1278 strbuf_release(&tmp);
7bd9bcf3
MH
1279 return ret;
1280}
1281
7bd9bcf3 1282static int write_ref_to_lockfile(struct ref_lock *lock,
4417df8c 1283 const struct object_id *oid, struct strbuf *err);
f18a7892
MH
1284static int commit_ref_update(struct files_ref_store *refs,
1285 struct ref_lock *lock,
4417df8c 1286 const struct object_id *oid, const char *logmsg,
5d9b2de4 1287 struct strbuf *err);
7bd9bcf3 1288
52d59cc6 1289static int files_copy_or_rename_ref(struct ref_store *ref_store,
9b6b40d9 1290 const char *oldrefname, const char *newrefname,
52d59cc6 1291 const char *logmsg, int copy)
7bd9bcf3 1292{
9b6b40d9 1293 struct files_ref_store *refs =
9e7ec634 1294 files_downcast(ref_store, REF_STORE_WRITE, "rename_ref");
4417df8c 1295 struct object_id oid, orig_oid;
7bd9bcf3
MH
1296 int flag = 0, logmoved = 0;
1297 struct ref_lock *lock;
1298 struct stat loginfo;
e9dcc305
NTND
1299 struct strbuf sb_oldref = STRBUF_INIT;
1300 struct strbuf sb_newref = STRBUF_INIT;
1301 struct strbuf tmp_renamed_log = STRBUF_INIT;
1302 int log, ret;
7bd9bcf3
MH
1303 struct strbuf err = STRBUF_INIT;
1304
802de3da
NTND
1305 files_reflog_path(refs, &sb_oldref, oldrefname);
1306 files_reflog_path(refs, &sb_newref, newrefname);
1307 files_reflog_path(refs, &tmp_renamed_log, TMP_RENAMED_LOG);
e9dcc305
NTND
1308
1309 log = !lstat(sb_oldref.buf, &loginfo);
0a3f07d6
NTND
1310 if (log && S_ISLNK(loginfo.st_mode)) {
1311 ret = error("reflog for %s is a symlink", oldrefname);
1312 goto out;
1313 }
7bd9bcf3 1314
2f40e954
NTND
1315 if (!refs_resolve_ref_unsafe(&refs->base, oldrefname,
1316 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
49e61479 1317 &orig_oid, &flag)) {
0a3f07d6
NTND
1318 ret = error("refname %s not found", oldrefname);
1319 goto out;
1320 }
e711b1af 1321
0a3f07d6 1322 if (flag & REF_ISSYMREF) {
52d59cc6
SD
1323 if (copy)
1324 ret = error("refname %s is a symbolic ref, copying it is not supported",
1325 oldrefname);
1326 else
1327 ret = error("refname %s is a symbolic ref, renaming it is not supported",
1328 oldrefname);
0a3f07d6
NTND
1329 goto out;
1330 }
7d2df051 1331 if (!refs_rename_ref_available(&refs->base, oldrefname, newrefname)) {
0a3f07d6
NTND
1332 ret = 1;
1333 goto out;
1334 }
7bd9bcf3 1335
52d59cc6 1336 if (!copy && log && rename(sb_oldref.buf, tmp_renamed_log.buf)) {
a5c1efd6 1337 ret = error("unable to move logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",
0a3f07d6
NTND
1338 oldrefname, strerror(errno));
1339 goto out;
1340 }
7bd9bcf3 1341
52d59cc6
SD
1342 if (copy && log && copy_file(tmp_renamed_log.buf, sb_oldref.buf, 0644)) {
1343 ret = error("unable to copy logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",
1344 oldrefname, strerror(errno));
1345 goto out;
1346 }
1347
1348 if (!copy && refs_delete_ref(&refs->base, logmsg, oldrefname,
91774afc 1349 &orig_oid, REF_NO_DEREF)) {
7bd9bcf3
MH
1350 error("unable to delete old %s", oldrefname);
1351 goto rollback;
1352 }
1353
12fd3496 1354 /*
4417df8c 1355 * Since we are doing a shallow lookup, oid is not the
1356 * correct value to pass to delete_ref as old_oid. But that
1357 * doesn't matter, because an old_oid check wouldn't add to
12fd3496
DT
1358 * the safety anyway; we want to delete the reference whatever
1359 * its current value.
1360 */
52d59cc6 1361 if (!copy && !refs_read_ref_full(&refs->base, newrefname,
2f40e954 1362 RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
34c290a6 1363 &oid, NULL) &&
2f40e954 1364 refs_delete_ref(&refs->base, NULL, newrefname,
91774afc 1365 NULL, REF_NO_DEREF)) {
58364324 1366 if (errno == EISDIR) {
7bd9bcf3
MH
1367 struct strbuf path = STRBUF_INIT;
1368 int result;
1369
19e02f4f 1370 files_ref_path(refs, &path, newrefname);
7bd9bcf3
MH
1371 result = remove_empty_directories(&path);
1372 strbuf_release(&path);
1373
1374 if (result) {
1375 error("Directory not empty: %s", newrefname);
1376 goto rollback;
1377 }
1378 } else {
1379 error("unable to delete existing %s", newrefname);
1380 goto rollback;
1381 }
1382 }
1383
802de3da 1384 if (log && rename_tmp_log(refs, newrefname))
7bd9bcf3
MH
1385 goto rollback;
1386
1387 logmoved = log;
1388
4f01e508 1389 lock = lock_ref_oid_basic(refs, newrefname, NULL, NULL, NULL,
91774afc 1390 REF_NO_DEREF, NULL, &err);
7bd9bcf3 1391 if (!lock) {
52d59cc6
SD
1392 if (copy)
1393 error("unable to copy '%s' to '%s': %s", oldrefname, newrefname, err.buf);
1394 else
1395 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);
7bd9bcf3
MH
1396 strbuf_release(&err);
1397 goto rollback;
1398 }
4417df8c 1399 oidcpy(&lock->old_oid, &orig_oid);
7bd9bcf3 1400
4417df8c 1401 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||
1402 commit_ref_update(refs, lock, &orig_oid, logmsg, &err)) {
7bd9bcf3
MH
1403 error("unable to write current sha1 into %s: %s", newrefname, err.buf);
1404 strbuf_release(&err);
1405 goto rollback;
1406 }
1407
0a3f07d6
NTND
1408 ret = 0;
1409 goto out;
7bd9bcf3
MH
1410
1411 rollback:
4f01e508 1412 lock = lock_ref_oid_basic(refs, oldrefname, NULL, NULL, NULL,
91774afc 1413 REF_NO_DEREF, NULL, &err);
7bd9bcf3
MH
1414 if (!lock) {
1415 error("unable to lock %s for rollback: %s", oldrefname, err.buf);
1416 strbuf_release(&err);
1417 goto rollbacklog;
1418 }
1419
1420 flag = log_all_ref_updates;
341fb286 1421 log_all_ref_updates = LOG_REFS_NONE;
4417df8c 1422 if (write_ref_to_lockfile(lock, &orig_oid, &err) ||
1423 commit_ref_update(refs, lock, &orig_oid, NULL, &err)) {
7bd9bcf3
MH
1424 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);
1425 strbuf_release(&err);
1426 }
1427 log_all_ref_updates = flag;
1428
1429 rollbacklog:
e9dcc305 1430 if (logmoved && rename(sb_newref.buf, sb_oldref.buf))
7bd9bcf3
MH
1431 error("unable to restore logfile %s from %s: %s",
1432 oldrefname, newrefname, strerror(errno));
1433 if (!logmoved && log &&
e9dcc305 1434 rename(tmp_renamed_log.buf, sb_oldref.buf))
a5c1efd6 1435 error("unable to restore logfile %s from logs/"TMP_RENAMED_LOG": %s",
7bd9bcf3 1436 oldrefname, strerror(errno));
0a3f07d6
NTND
1437 ret = 1;
1438 out:
e9dcc305
NTND
1439 strbuf_release(&sb_newref);
1440 strbuf_release(&sb_oldref);
1441 strbuf_release(&tmp_renamed_log);
1442
0a3f07d6 1443 return ret;
7bd9bcf3
MH
1444}
1445
52d59cc6
SD
1446static int files_rename_ref(struct ref_store *ref_store,
1447 const char *oldrefname, const char *newrefname,
1448 const char *logmsg)
1449{
1450 return files_copy_or_rename_ref(ref_store, oldrefname,
1451 newrefname, logmsg, 0);
1452}
1453
1454static int files_copy_ref(struct ref_store *ref_store,
1455 const char *oldrefname, const char *newrefname,
1456 const char *logmsg)
1457{
1458 return files_copy_or_rename_ref(ref_store, oldrefname,
1459 newrefname, logmsg, 1);
1460}
1461
83a3069a 1462static int close_ref_gently(struct ref_lock *lock)
7bd9bcf3 1463{
ee4d8e45 1464 if (close_lock_file_gently(&lock->lk))
7bd9bcf3
MH
1465 return -1;
1466 return 0;
1467}
1468
1469static int commit_ref(struct ref_lock *lock)
1470{
ee4d8e45 1471 char *path = get_locked_file_path(&lock->lk);
5387c0d8
MH
1472 struct stat st;
1473
1474 if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {
1475 /*
1476 * There is a directory at the path we want to rename
1477 * the lockfile to. Hopefully it is empty; try to
1478 * delete it.
1479 */
1480 size_t len = strlen(path);
1481 struct strbuf sb_path = STRBUF_INIT;
1482
1483 strbuf_attach(&sb_path, path, len, len);
1484
1485 /*
1486 * If this fails, commit_lock_file() will also fail
1487 * and will report the problem.
1488 */
1489 remove_empty_directories(&sb_path);
1490 strbuf_release(&sb_path);
1491 } else {
1492 free(path);
1493 }
1494
ee4d8e45 1495 if (commit_lock_file(&lock->lk))
7bd9bcf3
MH
1496 return -1;
1497 return 0;
1498}
1499
1fb0c809
MH
1500static int open_or_create_logfile(const char *path, void *cb)
1501{
1502 int *fd = cb;
1503
1504 *fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666);
1505 return (*fd < 0) ? -1 : 0;
1506}
1507
7bd9bcf3 1508/*
4533e534
MH
1509 * Create a reflog for a ref. If force_create = 0, only create the
1510 * reflog for certain refs (those for which should_autocreate_reflog
1511 * returns non-zero). Otherwise, create it regardless of the reference
1512 * name. If the logfile already existed or was created, return 0 and
1513 * set *logfd to the file descriptor opened for appending to the file.
1514 * If no logfile exists and we decided not to create one, return 0 and
1515 * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and
1516 * return -1.
7bd9bcf3 1517 */
802de3da
NTND
1518static int log_ref_setup(struct files_ref_store *refs,
1519 const char *refname, int force_create,
4533e534 1520 int *logfd, struct strbuf *err)
7bd9bcf3 1521{
802de3da
NTND
1522 struct strbuf logfile_sb = STRBUF_INIT;
1523 char *logfile;
1524
1525 files_reflog_path(refs, &logfile_sb, refname);
1526 logfile = strbuf_detach(&logfile_sb, NULL);
7bd9bcf3 1527
7bd9bcf3 1528 if (force_create || should_autocreate_reflog(refname)) {
4533e534 1529 if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) {
1fb0c809
MH
1530 if (errno == ENOENT)
1531 strbuf_addf(err, "unable to create directory for '%s': "
4533e534 1532 "%s", logfile, strerror(errno));
1fb0c809
MH
1533 else if (errno == EISDIR)
1534 strbuf_addf(err, "there are still logs under '%s'",
4533e534 1535 logfile);
1fb0c809 1536 else
854bda6b 1537 strbuf_addf(err, "unable to append to '%s': %s",
4533e534 1538 logfile, strerror(errno));
7bd9bcf3 1539
4533e534 1540 goto error;
7bd9bcf3 1541 }
854bda6b 1542 } else {
4533e534 1543 *logfd = open(logfile, O_APPEND | O_WRONLY, 0666);
e404f459 1544 if (*logfd < 0) {
854bda6b
MH
1545 if (errno == ENOENT || errno == EISDIR) {
1546 /*
1547 * The logfile doesn't already exist,
1548 * but that is not an error; it only
1549 * means that we won't write log
1550 * entries to it.
1551 */
1552 ;
1553 } else {
1554 strbuf_addf(err, "unable to append to '%s': %s",
4533e534
MH
1555 logfile, strerror(errno));
1556 goto error;
854bda6b 1557 }
7bd9bcf3
MH
1558 }
1559 }
1560
e404f459 1561 if (*logfd >= 0)
4533e534 1562 adjust_shared_perm(logfile);
854bda6b 1563
4533e534 1564 free(logfile);
7bd9bcf3 1565 return 0;
7bd9bcf3 1566
4533e534
MH
1567error:
1568 free(logfile);
1569 return -1;
7bd9bcf3 1570}
7bd9bcf3 1571
e3688bd6
DT
1572static int files_create_reflog(struct ref_store *ref_store,
1573 const char *refname, int force_create,
1574 struct strbuf *err)
7bd9bcf3 1575{
802de3da 1576 struct files_ref_store *refs =
9e7ec634 1577 files_downcast(ref_store, REF_STORE_WRITE, "create_reflog");
e404f459 1578 int fd;
7bd9bcf3 1579
802de3da 1580 if (log_ref_setup(refs, refname, force_create, &fd, err))
4533e534
MH
1581 return -1;
1582
e404f459
MH
1583 if (fd >= 0)
1584 close(fd);
4533e534
MH
1585
1586 return 0;
7bd9bcf3
MH
1587}
1588
4417df8c 1589static int log_ref_write_fd(int fd, const struct object_id *old_oid,
1590 const struct object_id *new_oid,
7bd9bcf3
MH
1591 const char *committer, const char *msg)
1592{
80a6c207
BP
1593 struct strbuf sb = STRBUF_INIT;
1594 int ret = 0;
1595
1596 strbuf_addf(&sb, "%s %s %s", oid_to_hex(old_oid), oid_to_hex(new_oid), committer);
1597 if (msg && *msg)
1598 copy_reflog_msg(&sb, msg);
1599 strbuf_addch(&sb, '\n');
1600 if (write_in_full(fd, sb.buf, sb.len) < 0)
1601 ret = -1;
1602 strbuf_release(&sb);
1603 return ret;
7bd9bcf3
MH
1604}
1605
802de3da 1606static int files_log_ref_write(struct files_ref_store *refs,
4417df8c 1607 const char *refname, const struct object_id *old_oid,
1608 const struct object_id *new_oid, const char *msg,
11f8457f 1609 int flags, struct strbuf *err)
7bd9bcf3 1610{
e404f459 1611 int logfd, result;
7bd9bcf3 1612
341fb286
CW
1613 if (log_all_ref_updates == LOG_REFS_UNSET)
1614 log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;
7bd9bcf3 1615
802de3da
NTND
1616 result = log_ref_setup(refs, refname,
1617 flags & REF_FORCE_CREATE_REFLOG,
4533e534 1618 &logfd, err);
7bd9bcf3
MH
1619
1620 if (result)
1621 return result;
1622
7bd9bcf3
MH
1623 if (logfd < 0)
1624 return 0;
4417df8c 1625 result = log_ref_write_fd(logfd, old_oid, new_oid,
7bd9bcf3
MH
1626 git_committer_info(0), msg);
1627 if (result) {
e9dcc305 1628 struct strbuf sb = STRBUF_INIT;
87b21e05
MH
1629 int save_errno = errno;
1630
802de3da 1631 files_reflog_path(refs, &sb, refname);
87b21e05 1632 strbuf_addf(err, "unable to append to '%s': %s",
e9dcc305
NTND
1633 sb.buf, strerror(save_errno));
1634 strbuf_release(&sb);
7bd9bcf3
MH
1635 close(logfd);
1636 return -1;
1637 }
1638 if (close(logfd)) {
e9dcc305 1639 struct strbuf sb = STRBUF_INIT;
87b21e05
MH
1640 int save_errno = errno;
1641
802de3da 1642 files_reflog_path(refs, &sb, refname);
87b21e05 1643 strbuf_addf(err, "unable to append to '%s': %s",
e9dcc305
NTND
1644 sb.buf, strerror(save_errno));
1645 strbuf_release(&sb);
7bd9bcf3
MH
1646 return -1;
1647 }
1648 return 0;
1649}
1650
7bd9bcf3 1651/*
78fb4579
MH
1652 * Write oid into the open lockfile, then close the lockfile. On
1653 * errors, rollback the lockfile, fill in *err and return -1.
7bd9bcf3
MH
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
109cd76d 1662 o = parse_object(the_repository, 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);
2ae2e2a1 1678 if (write_in_full(fd, oid_to_hex(oid), the_hash_algo->hexsz) < 0 ||
06f46f23 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,
91774afc 1819 NULL, NULL, REF_NO_DEREF, NULL,
4f01e508 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)
033abf97 2008 BUG("reverse reflog parser had leftover data");
7bd9bcf3
MH
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{
033abf97 2086 BUG("ref_iterator_peel() called for reflog_iterator");
2880d16f
MH
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) ||
acedcde7 2180 (update->flags & REF_IS_PRUNING) ||
92b1551b
MH
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",
91774afc 2203 update->flags | REF_LOG_ONLY | REF_NO_DEREF,
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
91774afc
MH
2222 * REF_NO_DEREF set. Split it into two updates:
2223 * - The original update, but with REF_LOG_ONLY and REF_NO_DEREF set
92b1551b
MH
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
78fb4579 2275 * doesn't need to check its old OID value, as that will be
6e30b2f6
MH
2276 * done when new_update is processed.
2277 */
91774afc 2278 update->flags |= REF_LOG_ONLY | REF_NO_DEREF;
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) ||
4a7e27e9 2318 oideq(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.
78fb4579 2344 * - Check that its old OID value (if specified) is correct, and in
92b1551b
MH
2345 * any case record it in update->lock->old_oid for later use when
2346 * writing the reflog.
91774afc 2347 * - If it is a symref update without REF_NO_DEREF, split it up into a
92b1551b
MH
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) {
91774afc 2395 if (update->flags & REF_NO_DEREF) {
6e30b2f6
MH
2396 /*
2397 * We won't be reading the referent as part of
2398 * the transaction, so we have to read it here
78fb4579 2399 * to record and possibly check old_oid:
6e30b2f6 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
78fb4579 2419 * and verify old_oid for this update as part
6e30b2f6
MH
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
78fb4579 2439 * symref update, record the old OID in the parent
6e30b2f6
MH
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) &&
4a7e27e9 2454 oideq(&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 2566 * same refname as any existing ones.) Also fail if any of the
acedcde7 2567 * updates use REF_IS_PRUNING without REF_NO_DEREF.
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
acedcde7 2574 if ((update->flags & REF_IS_PRUNING) &&
91774afc 2575 !(update->flags & REF_NO_DEREF))
acedcde7 2576 BUG("REF_IS_PRUNING set without REF_NO_DEREF");
62c72d1f 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) &&
acedcde7 2635 !(update->flags & REF_IS_PRUNING)) {
dc39e099
MH
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,
91774afc 2654 REF_HAVE_NEW | REF_NO_DEREF,
b0ca4110 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;
7c6bd25c
MH
2666
2667 if (is_packed_transaction_needed(refs->packed_ref_store,
2668 packed_transaction)) {
2669 ret = ref_transaction_prepare(packed_transaction, err);
2670 } else {
2671 /*
2672 * We can skip rewriting the `packed-refs`
2673 * file. But we do need to leave it locked, so
2674 * that somebody else doesn't pack a reference
2675 * that we are trying to delete.
2676 */
2677 if (ref_transaction_abort(packed_transaction, err)) {
2678 ret = TRANSACTION_GENERIC_ERROR;
2679 goto cleanup;
2680 }
2681 backend_data->packed_transaction = NULL;
2682 }
30173b88
MH
2683 }
2684
2685cleanup:
2686 free(head_ref);
2687 string_list_clear(&affected_refnames, 0);
2688
2689 if (ret)
dc39e099 2690 files_transaction_cleanup(refs, transaction);
30173b88
MH
2691 else
2692 transaction->state = REF_TRANSACTION_PREPARED;
2693
2694 return ret;
2695}
2696
2697static int files_transaction_finish(struct ref_store *ref_store,
2698 struct ref_transaction *transaction,
2699 struct strbuf *err)
2700{
2701 struct files_ref_store *refs =
2702 files_downcast(ref_store, 0, "ref_transaction_finish");
2703 size_t i;
2704 int ret = 0;
30173b88 2705 struct strbuf sb = STRBUF_INIT;
dc39e099
MH
2706 struct files_transaction_backend_data *backend_data;
2707 struct ref_transaction *packed_transaction;
2708
30173b88
MH
2709
2710 assert(err);
2711
2712 if (!transaction->nr) {
2713 transaction->state = REF_TRANSACTION_CLOSED;
2714 return 0;
7bd9bcf3 2715 }
7bd9bcf3 2716
dc39e099
MH
2717 backend_data = transaction->backend_data;
2718 packed_transaction = backend_data->packed_transaction;
2719
7bd9bcf3 2720 /* Perform updates first so live commits remain referenced */
efe47281
MH
2721 for (i = 0; i < transaction->nr; i++) {
2722 struct ref_update *update = transaction->updates[i];
7d618264 2723 struct ref_lock *lock = update->backend_data;
7bd9bcf3 2724
d99aa884
DT
2725 if (update->flags & REF_NEEDS_COMMIT ||
2726 update->flags & REF_LOG_ONLY) {
802de3da
NTND
2727 if (files_log_ref_write(refs,
2728 lock->ref_name,
4417df8c 2729 &lock->old_oid,
2730 &update->new_oid,
81b1b6d4
MH
2731 update->msg, update->flags,
2732 err)) {
92b1551b
MH
2733 char *old_msg = strbuf_detach(err, NULL);
2734
2735 strbuf_addf(err, "cannot update the ref '%s': %s",
2736 lock->ref_name, old_msg);
2737 free(old_msg);
2738 unlock_ref(lock);
7d618264 2739 update->backend_data = NULL;
7bd9bcf3
MH
2740 ret = TRANSACTION_GENERIC_ERROR;
2741 goto cleanup;
7bd9bcf3
MH
2742 }
2743 }
7bd9bcf3 2744 if (update->flags & REF_NEEDS_COMMIT) {
00eebe35 2745 clear_loose_ref_cache(refs);
92b1551b
MH
2746 if (commit_ref(lock)) {
2747 strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
2748 unlock_ref(lock);
7d618264 2749 update->backend_data = NULL;
7bd9bcf3
MH
2750 ret = TRANSACTION_GENERIC_ERROR;
2751 goto cleanup;
7bd9bcf3
MH
2752 }
2753 }
2754 }
dc39e099 2755
5e00a6c8
MH
2756 /*
2757 * Now that updates are safely completed, we can perform
2758 * deletes. First delete the reflogs of any references that
2759 * will be deleted, since (in the unexpected event of an
2760 * error) leaving a reference without a reflog is less bad
2761 * than leaving a reflog without a reference (the latter is a
2762 * mildly invalid repository state):
2763 */
2764 for (i = 0; i < transaction->nr; i++) {
2765 struct ref_update *update = transaction->updates[i];
2766 if (update->flags & REF_DELETING &&
2767 !(update->flags & REF_LOG_ONLY) &&
acedcde7 2768 !(update->flags & REF_IS_PRUNING)) {
5e00a6c8
MH
2769 strbuf_reset(&sb);
2770 files_reflog_path(refs, &sb, update->refname);
2771 if (!unlink_or_warn(sb.buf))
2772 try_remove_empty_parents(refs, update->refname,
2773 REMOVE_EMPTY_PARENTS_REFLOG);
2774 }
2775 }
2776
dc39e099
MH
2777 /*
2778 * Perform deletes now that updates are safely completed.
2779 *
2780 * First delete any packed versions of the references, while
2781 * retaining the packed-refs lock:
2782 */
2783 if (packed_transaction) {
2784 ret = ref_transaction_commit(packed_transaction, err);
2785 ref_transaction_free(packed_transaction);
2786 packed_transaction = NULL;
2787 backend_data->packed_transaction = NULL;
2788 if (ret)
2789 goto cleanup;
2790 }
2791
2792 /* Now delete the loose versions of the references: */
efe47281
MH
2793 for (i = 0; i < transaction->nr; i++) {
2794 struct ref_update *update = transaction->updates[i];
7d618264 2795 struct ref_lock *lock = update->backend_data;
7bd9bcf3 2796
d99aa884
DT
2797 if (update->flags & REF_DELETING &&
2798 !(update->flags & REF_LOG_ONLY)) {
ce0af24d
MH
2799 if (!(update->type & REF_ISPACKED) ||
2800 update->type & REF_ISSYMREF) {
2801 /* It is a loose reference. */
e9dcc305 2802 strbuf_reset(&sb);
19e02f4f 2803 files_ref_path(refs, &sb, lock->ref_name);
e9dcc305 2804 if (unlink_or_msg(sb.buf, err)) {
ce0af24d
MH
2805 ret = TRANSACTION_GENERIC_ERROR;
2806 goto cleanup;
2807 }
44639777 2808 update->flags |= REF_DELETED_LOOSE;
7bd9bcf3 2809 }
7bd9bcf3
MH
2810 }
2811 }
2812
00eebe35 2813 clear_loose_ref_cache(refs);
7bd9bcf3
MH
2814
2815cleanup:
dc39e099 2816 files_transaction_cleanup(refs, transaction);
7bd9bcf3 2817
44639777
MH
2818 for (i = 0; i < transaction->nr; i++) {
2819 struct ref_update *update = transaction->updates[i];
44639777
MH
2820
2821 if (update->flags & REF_DELETED_LOOSE) {
2822 /*
2823 * The loose reference was deleted. Delete any
2824 * empty parent directories. (Note that this
2825 * can only work because we have already
2826 * removed the lockfile.)
2827 */
802de3da 2828 try_remove_empty_parents(refs, update->refname,
44639777
MH
2829 REMOVE_EMPTY_PARENTS_REF);
2830 }
2831 }
2832
30173b88 2833 strbuf_release(&sb);
7bd9bcf3
MH
2834 return ret;
2835}
2836
30173b88
MH
2837static int files_transaction_abort(struct ref_store *ref_store,
2838 struct ref_transaction *transaction,
2839 struct strbuf *err)
2840{
dc39e099
MH
2841 struct files_ref_store *refs =
2842 files_downcast(ref_store, 0, "ref_transaction_abort");
2843
2844 files_transaction_cleanup(refs, transaction);
30173b88
MH
2845 return 0;
2846}
2847
7bd9bcf3
MH
2848static int ref_present(const char *refname,
2849 const struct object_id *oid, int flags, void *cb_data)
2850{
2851 struct string_list *affected_refnames = cb_data;
2852
2853 return string_list_has_string(affected_refnames, refname);
2854}
2855
fc681463
DT
2856static int files_initial_transaction_commit(struct ref_store *ref_store,
2857 struct ref_transaction *transaction,
2858 struct strbuf *err)
7bd9bcf3 2859{
d99825ab 2860 struct files_ref_store *refs =
9e7ec634
NTND
2861 files_downcast(ref_store, REF_STORE_WRITE,
2862 "initial_ref_transaction_commit");
43a2dfde
MH
2863 size_t i;
2864 int ret = 0;
7bd9bcf3 2865 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
1444bfe0 2866 struct ref_transaction *packed_transaction = NULL;
7bd9bcf3
MH
2867
2868 assert(err);
2869
2870 if (transaction->state != REF_TRANSACTION_OPEN)
033abf97 2871 BUG("commit called for transaction that is not open");
7bd9bcf3
MH
2872
2873 /* Fail if a refname appears more than once in the transaction: */
efe47281
MH
2874 for (i = 0; i < transaction->nr; i++)
2875 string_list_append(&affected_refnames,
2876 transaction->updates[i]->refname);
7bd9bcf3
MH
2877 string_list_sort(&affected_refnames);
2878 if (ref_update_reject_duplicates(&affected_refnames, err)) {
2879 ret = TRANSACTION_GENERIC_ERROR;
2880 goto cleanup;
2881 }
2882
2883 /*
2884 * It's really undefined to call this function in an active
2885 * repository or when there are existing references: we are
2886 * only locking and changing packed-refs, so (1) any
2887 * simultaneous processes might try to change a reference at
2888 * the same time we do, and (2) any existing loose versions of
2889 * the references that we are setting would have precedence
2890 * over our values. But some remote helpers create the remote
2891 * "HEAD" and "master" branches before calling this function,
2892 * so here we really only check that none of the references
2893 * that we are creating already exists.
2894 */
2f40e954
NTND
2895 if (refs_for_each_rawref(&refs->base, ref_present,
2896 &affected_refnames))
033abf97 2897 BUG("initial ref transaction called with existing refs");
7bd9bcf3 2898
1444bfe0
MH
2899 packed_transaction = ref_store_transaction_begin(refs->packed_ref_store, err);
2900 if (!packed_transaction) {
2901 ret = TRANSACTION_GENERIC_ERROR;
2902 goto cleanup;
2903 }
2904
efe47281
MH
2905 for (i = 0; i < transaction->nr; i++) {
2906 struct ref_update *update = transaction->updates[i];
7bd9bcf3
MH
2907
2908 if ((update->flags & REF_HAVE_OLD) &&
98491298 2909 !is_null_oid(&update->old_oid))
033abf97 2910 BUG("initial ref transaction with old_sha1 set");
7d2df051
NTND
2911 if (refs_verify_refname_available(&refs->base, update->refname,
2912 &affected_refnames, NULL,
2913 err)) {
7bd9bcf3
MH
2914 ret = TRANSACTION_NAME_CONFLICT;
2915 goto cleanup;
2916 }
1444bfe0
MH
2917
2918 /*
2919 * Add a reference creation for this reference to the
2920 * packed-refs transaction:
2921 */
2922 ref_transaction_add_update(packed_transaction, update->refname,
2923 update->flags & ~REF_HAVE_OLD,
89f3bbdd 2924 &update->new_oid, &update->old_oid,
1444bfe0 2925 NULL);
7bd9bcf3
MH
2926 }
2927
c8bed835 2928 if (packed_refs_lock(refs->packed_ref_store, 0, err)) {
7bd9bcf3
MH
2929 ret = TRANSACTION_GENERIC_ERROR;
2930 goto cleanup;
2931 }
2932
1444bfe0 2933 if (initial_ref_transaction_commit(packed_transaction, err)) {
7bd9bcf3 2934 ret = TRANSACTION_GENERIC_ERROR;
7bd9bcf3
MH
2935 }
2936
81fcb698 2937 packed_refs_unlock(refs->packed_ref_store);
7bd9bcf3 2938cleanup:
1444bfe0
MH
2939 if (packed_transaction)
2940 ref_transaction_free(packed_transaction);
7bd9bcf3
MH
2941 transaction->state = REF_TRANSACTION_CLOSED;
2942 string_list_clear(&affected_refnames, 0);
2943 return ret;
2944}
2945
2946struct expire_reflog_cb {
2947 unsigned int flags;
2948 reflog_expiry_should_prune_fn *should_prune_fn;
2949 void *policy_cb;
2950 FILE *newlog;
9461d272 2951 struct object_id last_kept_oid;
7bd9bcf3
MH
2952};
2953
9461d272 2954static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
dddbad72 2955 const char *email, timestamp_t timestamp, int tz,
7bd9bcf3
MH
2956 const char *message, void *cb_data)
2957{
2958 struct expire_reflog_cb *cb = cb_data;
2959 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
2960
2961 if (cb->flags & EXPIRE_REFLOGS_REWRITE)
9461d272 2962 ooid = &cb->last_kept_oid;
7bd9bcf3 2963
4322478a 2964 if ((*cb->should_prune_fn)(ooid, noid, email, timestamp, tz,
7bd9bcf3
MH
2965 message, policy_cb)) {
2966 if (!cb->newlog)
2967 printf("would prune %s", message);
2968 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
2969 printf("prune %s", message);
2970 } else {
2971 if (cb->newlog) {
cb71f8bd 2972 fprintf(cb->newlog, "%s %s %s %"PRItime" %+05d\t%s",
9461d272 2973 oid_to_hex(ooid), oid_to_hex(noid),
7bd9bcf3 2974 email, timestamp, tz, message);
9461d272 2975 oidcpy(&cb->last_kept_oid, noid);
7bd9bcf3
MH
2976 }
2977 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
2978 printf("keep %s", message);
2979 }
2980 return 0;
2981}
2982
e3688bd6 2983static int files_reflog_expire(struct ref_store *ref_store,
0155f710 2984 const char *refname, const struct object_id *oid,
e3688bd6
DT
2985 unsigned int flags,
2986 reflog_expiry_prepare_fn prepare_fn,
2987 reflog_expiry_should_prune_fn should_prune_fn,
2988 reflog_expiry_cleanup_fn cleanup_fn,
2989 void *policy_cb_data)
7bd9bcf3 2990{
7eb27cdf 2991 struct files_ref_store *refs =
9e7ec634 2992 files_downcast(ref_store, REF_STORE_WRITE, "reflog_expire");
b2275868 2993 struct lock_file reflog_lock = LOCK_INIT;
7bd9bcf3
MH
2994 struct expire_reflog_cb cb;
2995 struct ref_lock *lock;
802de3da 2996 struct strbuf log_file_sb = STRBUF_INIT;
7bd9bcf3
MH
2997 char *log_file;
2998 int status = 0;
2999 int type;
3000 struct strbuf err = STRBUF_INIT;
3001
3002 memset(&cb, 0, sizeof(cb));
3003 cb.flags = flags;
3004 cb.policy_cb = policy_cb_data;
3005 cb.should_prune_fn = should_prune_fn;
3006
3007 /*
3008 * The reflog file is locked by holding the lock on the
3009 * reference itself, plus we might need to update the
3010 * reference if --updateref was specified:
3011 */
4f01e508 3012 lock = lock_ref_oid_basic(refs, refname, oid,
91774afc 3013 NULL, NULL, REF_NO_DEREF,
4f01e508 3014 &type, &err);
7bd9bcf3
MH
3015 if (!lock) {
3016 error("cannot lock ref '%s': %s", refname, err.buf);
3017 strbuf_release(&err);
3018 return -1;
3019 }
2f40e954 3020 if (!refs_reflog_exists(ref_store, refname)) {
7bd9bcf3
MH
3021 unlock_ref(lock);
3022 return 0;
3023 }
3024
802de3da
NTND
3025 files_reflog_path(refs, &log_file_sb, refname);
3026 log_file = strbuf_detach(&log_file_sb, NULL);
7bd9bcf3
MH
3027 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
3028 /*
3029 * Even though holding $GIT_DIR/logs/$reflog.lock has
3030 * no locking implications, we use the lock_file
3031 * machinery here anyway because it does a lot of the
3032 * work we need, including cleaning up if the program
3033 * exits unexpectedly.
3034 */
3035 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
3036 struct strbuf err = STRBUF_INIT;
3037 unable_to_lock_message(log_file, errno, &err);
3038 error("%s", err.buf);
3039 strbuf_release(&err);
3040 goto failure;
3041 }
3042 cb.newlog = fdopen_lock_file(&reflog_lock, "w");
3043 if (!cb.newlog) {
3044 error("cannot fdopen %s (%s)",
3045 get_lock_file_path(&reflog_lock), strerror(errno));
3046 goto failure;
3047 }
3048 }
3049
0155f710 3050 (*prepare_fn)(refname, oid, cb.policy_cb);
2f40e954 3051 refs_for_each_reflog_ent(ref_store, refname, expire_reflog_ent, &cb);
7bd9bcf3
MH
3052 (*cleanup_fn)(cb.policy_cb);
3053
3054 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
3055 /*
3056 * It doesn't make sense to adjust a reference pointed
3057 * to by a symbolic ref based on expiring entries in
3058 * the symbolic reference's reflog. Nor can we update
3059 * a reference if there are no remaining reflog
3060 * entries.
3061 */
3062 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&
3063 !(type & REF_ISSYMREF) &&
9461d272 3064 !is_null_oid(&cb.last_kept_oid);
7bd9bcf3 3065
83a3069a 3066 if (close_lock_file_gently(&reflog_lock)) {
7bd9bcf3
MH
3067 status |= error("couldn't write %s: %s", log_file,
3068 strerror(errno));
83a3069a 3069 rollback_lock_file(&reflog_lock);
7bd9bcf3 3070 } else if (update &&
ee4d8e45 3071 (write_in_full(get_lock_file_fd(&lock->lk),
2ae2e2a1 3072 oid_to_hex(&cb.last_kept_oid), the_hash_algo->hexsz) < 0 ||
88780c37 3073 write_str_in_full(get_lock_file_fd(&lock->lk), "\n") < 0 ||
83a3069a 3074 close_ref_gently(lock) < 0)) {
7bd9bcf3 3075 status |= error("couldn't write %s",
ee4d8e45 3076 get_lock_file_path(&lock->lk));
7bd9bcf3
MH
3077 rollback_lock_file(&reflog_lock);
3078 } else if (commit_lock_file(&reflog_lock)) {
e0048d3e 3079 status |= error("unable to write reflog '%s' (%s)",
7bd9bcf3
MH
3080 log_file, strerror(errno));
3081 } else if (update && commit_ref(lock)) {
3082 status |= error("couldn't set %s", lock->ref_name);
3083 }
3084 }
3085 free(log_file);
3086 unlock_ref(lock);
3087 return status;
3088
3089 failure:
3090 rollback_lock_file(&reflog_lock);
3091 free(log_file);
3092 unlock_ref(lock);
3093 return -1;
3094}
3dce444f 3095
6fb5acfd
DT
3096static int files_init_db(struct ref_store *ref_store, struct strbuf *err)
3097{
19e02f4f 3098 struct files_ref_store *refs =
9e7ec634 3099 files_downcast(ref_store, REF_STORE_WRITE, "init_db");
e9dcc305
NTND
3100 struct strbuf sb = STRBUF_INIT;
3101
6fb5acfd
DT
3102 /*
3103 * Create .git/refs/{heads,tags}
3104 */
19e02f4f 3105 files_ref_path(refs, &sb, "refs/heads");
e9dcc305
NTND
3106 safe_create_dir(sb.buf, 1);
3107
3108 strbuf_reset(&sb);
19e02f4f 3109 files_ref_path(refs, &sb, "refs/tags");
e9dcc305
NTND
3110 safe_create_dir(sb.buf, 1);
3111
3112 strbuf_release(&sb);
6fb5acfd
DT
3113 return 0;
3114}
3115
3dce444f
RS
3116struct ref_storage_be refs_be_files = {
3117 NULL,
00eebe35 3118 "files",
127b42a1 3119 files_ref_store_create,
6fb5acfd 3120 files_init_db,
30173b88
MH
3121 files_transaction_prepare,
3122 files_transaction_finish,
3123 files_transaction_abort,
fc681463 3124 files_initial_transaction_commit,
e1e33b72 3125
8231527e 3126 files_pack_refs,
284689ba 3127 files_create_symref,
a27dcf89 3128 files_delete_refs,
9b6b40d9 3129 files_rename_ref,
52d59cc6 3130 files_copy_ref,
8231527e 3131
1a769003 3132 files_ref_iterator_begin,
62665823 3133 files_read_raw_ref,
e3688bd6
DT
3134
3135 files_reflog_iterator_begin,
3136 files_for_each_reflog_ent,
3137 files_for_each_reflog_ent_reverse,
3138 files_reflog_exists,
3139 files_create_reflog,
3140 files_delete_reflog,
3141 files_reflog_expire
3dce444f 3142};