checkout,clone: check return value of create_symref
[git/git.git] / refs / files-backend.c
CommitLineData
7bd9bcf3
MH
1#include "../cache.h"
2#include "../refs.h"
3#include "refs-internal.h"
4#include "../lockfile.h"
5#include "../object.h"
6#include "../dir.h"
7
8struct ref_lock {
9 char *ref_name;
10 char *orig_ref_name;
11 struct lock_file *lk;
12 struct object_id old_oid;
13};
14
15struct ref_entry;
16
17/*
18 * Information used (along with the information in ref_entry) to
19 * describe a single cached reference. This data structure only
20 * occurs embedded in a union in struct ref_entry, and only when
21 * (ref_entry->flag & REF_DIR) is zero.
22 */
23struct ref_value {
24 /*
25 * The name of the object to which this reference resolves
26 * (which may be a tag object). If REF_ISBROKEN, this is
27 * null. If REF_ISSYMREF, then this is the name of the object
28 * referred to by the last reference in the symlink chain.
29 */
30 struct object_id oid;
31
32 /*
33 * If REF_KNOWS_PEELED, then this field holds the peeled value
34 * of this reference, or null if the reference is known not to
35 * be peelable. See the documentation for peel_ref() for an
36 * exact definition of "peelable".
37 */
38 struct object_id peeled;
39};
40
41struct ref_cache;
42
43/*
44 * Information used (along with the information in ref_entry) to
45 * describe a level in the hierarchy of references. This data
46 * structure only occurs embedded in a union in struct ref_entry, and
47 * only when (ref_entry.flag & REF_DIR) is set. In that case,
48 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
49 * in the directory have already been read:
50 *
51 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
52 * or packed references, already read.
53 *
54 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
55 * references that hasn't been read yet (nor has any of its
56 * subdirectories).
57 *
58 * Entries within a directory are stored within a growable array of
59 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
60 * sorted are sorted by their component name in strcmp() order and the
61 * remaining entries are unsorted.
62 *
63 * Loose references are read lazily, one directory at a time. When a
64 * directory of loose references is read, then all of the references
65 * in that directory are stored, and REF_INCOMPLETE stubs are created
66 * for any subdirectories, but the subdirectories themselves are not
67 * read. The reading is triggered by get_ref_dir().
68 */
69struct ref_dir {
70 int nr, alloc;
71
72 /*
73 * Entries with index 0 <= i < sorted are sorted by name. New
74 * entries are appended to the list unsorted, and are sorted
75 * only when required; thus we avoid the need to sort the list
76 * after the addition of every reference.
77 */
78 int sorted;
79
80 /* A pointer to the ref_cache that contains this ref_dir. */
81 struct ref_cache *ref_cache;
82
83 struct ref_entry **entries;
84};
85
86/*
87 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
88 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are
89 * public values; see refs.h.
90 */
91
92/*
93 * The field ref_entry->u.value.peeled of this value entry contains
94 * the correct peeled value for the reference, which might be
95 * null_sha1 if the reference is not a tag or if it is broken.
96 */
97#define REF_KNOWS_PEELED 0x10
98
99/* ref_entry represents a directory of references */
100#define REF_DIR 0x20
101
102/*
103 * Entry has not yet been read from disk (used only for REF_DIR
104 * entries representing loose references)
105 */
106#define REF_INCOMPLETE 0x40
107
108/*
109 * A ref_entry represents either a reference or a "subdirectory" of
110 * references.
111 *
112 * Each directory in the reference namespace is represented by a
113 * ref_entry with (flags & REF_DIR) set and containing a subdir member
114 * that holds the entries in that directory that have been read so
115 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
116 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
117 * used for loose reference directories.
118 *
119 * References are represented by a ref_entry with (flags & REF_DIR)
120 * unset and a value member that describes the reference's value. The
121 * flag member is at the ref_entry level, but it is also needed to
122 * interpret the contents of the value field (in other words, a
123 * ref_value object is not very much use without the enclosing
124 * ref_entry).
125 *
126 * Reference names cannot end with slash and directories' names are
127 * always stored with a trailing slash (except for the top-level
128 * directory, which is always denoted by ""). This has two nice
129 * consequences: (1) when the entries in each subdir are sorted
130 * lexicographically by name (as they usually are), the references in
131 * a whole tree can be generated in lexicographic order by traversing
132 * the tree in left-to-right, depth-first order; (2) the names of
133 * references and subdirectories cannot conflict, and therefore the
134 * presence of an empty subdirectory does not block the creation of a
135 * similarly-named reference. (The fact that reference names with the
136 * same leading components can conflict *with each other* is a
137 * separate issue that is regulated by verify_refname_available().)
138 *
139 * Please note that the name field contains the fully-qualified
140 * reference (or subdirectory) name. Space could be saved by only
141 * storing the relative names. But that would require the full names
142 * to be generated on the fly when iterating in do_for_each_ref(), and
143 * would break callback functions, who have always been able to assume
144 * that the name strings that they are passed will not be freed during
145 * the iteration.
146 */
147struct ref_entry {
148 unsigned char flag; /* ISSYMREF? ISPACKED? */
149 union {
150 struct ref_value value; /* if not (flags&REF_DIR) */
151 struct ref_dir subdir; /* if (flags&REF_DIR) */
152 } u;
153 /*
154 * The full name of the reference (e.g., "refs/heads/master")
155 * or the full name of the directory with a trailing slash
156 * (e.g., "refs/heads/"):
157 */
158 char name[FLEX_ARRAY];
159};
160
161static void read_loose_refs(const char *dirname, struct ref_dir *dir);
162static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len);
163static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
164 const char *dirname, size_t len,
165 int incomplete);
166static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry);
167
168static struct ref_dir *get_ref_dir(struct ref_entry *entry)
169{
170 struct ref_dir *dir;
171 assert(entry->flag & REF_DIR);
172 dir = &entry->u.subdir;
173 if (entry->flag & REF_INCOMPLETE) {
174 read_loose_refs(entry->name, dir);
175
176 /*
177 * Manually add refs/bisect, which, being
178 * per-worktree, might not appear in the directory
179 * listing for refs/ in the main repo.
180 */
181 if (!strcmp(entry->name, "refs/")) {
182 int pos = search_ref_dir(dir, "refs/bisect/", 12);
183 if (pos < 0) {
184 struct ref_entry *child_entry;
185 child_entry = create_dir_entry(dir->ref_cache,
186 "refs/bisect/",
187 12, 1);
188 add_entry_to_dir(dir, child_entry);
189 read_loose_refs("refs/bisect",
190 &child_entry->u.subdir);
191 }
192 }
193 entry->flag &= ~REF_INCOMPLETE;
194 }
195 return dir;
196}
197
198static struct ref_entry *create_ref_entry(const char *refname,
199 const unsigned char *sha1, int flag,
200 int check_name)
201{
202 int len;
203 struct ref_entry *ref;
204
205 if (check_name &&
206 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
207 die("Reference has invalid format: '%s'", refname);
208 len = strlen(refname) + 1;
209 ref = xmalloc(sizeof(struct ref_entry) + len);
210 hashcpy(ref->u.value.oid.hash, sha1);
211 oidclr(&ref->u.value.peeled);
212 memcpy(ref->name, refname, len);
213 ref->flag = flag;
214 return ref;
215}
216
217static void clear_ref_dir(struct ref_dir *dir);
218
219static void free_ref_entry(struct ref_entry *entry)
220{
221 if (entry->flag & REF_DIR) {
222 /*
223 * Do not use get_ref_dir() here, as that might
224 * trigger the reading of loose refs.
225 */
226 clear_ref_dir(&entry->u.subdir);
227 }
228 free(entry);
229}
230
231/*
232 * Add a ref_entry to the end of dir (unsorted). Entry is always
233 * stored directly in dir; no recursion into subdirectories is
234 * done.
235 */
236static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
237{
238 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
239 dir->entries[dir->nr++] = entry;
240 /* optimize for the case that entries are added in order */
241 if (dir->nr == 1 ||
242 (dir->nr == dir->sorted + 1 &&
243 strcmp(dir->entries[dir->nr - 2]->name,
244 dir->entries[dir->nr - 1]->name) < 0))
245 dir->sorted = dir->nr;
246}
247
248/*
249 * Clear and free all entries in dir, recursively.
250 */
251static void clear_ref_dir(struct ref_dir *dir)
252{
253 int i;
254 for (i = 0; i < dir->nr; i++)
255 free_ref_entry(dir->entries[i]);
256 free(dir->entries);
257 dir->sorted = dir->nr = dir->alloc = 0;
258 dir->entries = NULL;
259}
260
261/*
262 * Create a struct ref_entry object for the specified dirname.
263 * dirname is the name of the directory with a trailing slash (e.g.,
264 * "refs/heads/") or "" for the top-level directory.
265 */
266static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
267 const char *dirname, size_t len,
268 int incomplete)
269{
270 struct ref_entry *direntry;
271 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
272 memcpy(direntry->name, dirname, len);
273 direntry->name[len] = '\0';
274 direntry->u.subdir.ref_cache = ref_cache;
275 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
276 return direntry;
277}
278
279static int ref_entry_cmp(const void *a, const void *b)
280{
281 struct ref_entry *one = *(struct ref_entry **)a;
282 struct ref_entry *two = *(struct ref_entry **)b;
283 return strcmp(one->name, two->name);
284}
285
286static void sort_ref_dir(struct ref_dir *dir);
287
288struct string_slice {
289 size_t len;
290 const char *str;
291};
292
293static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
294{
295 const struct string_slice *key = key_;
296 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
297 int cmp = strncmp(key->str, ent->name, key->len);
298 if (cmp)
299 return cmp;
300 return '\0' - (unsigned char)ent->name[key->len];
301}
302
303/*
304 * Return the index of the entry with the given refname from the
305 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
306 * no such entry is found. dir must already be complete.
307 */
308static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
309{
310 struct ref_entry **r;
311 struct string_slice key;
312
313 if (refname == NULL || !dir->nr)
314 return -1;
315
316 sort_ref_dir(dir);
317 key.len = len;
318 key.str = refname;
319 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
320 ref_entry_cmp_sslice);
321
322 if (r == NULL)
323 return -1;
324
325 return r - dir->entries;
326}
327
328/*
329 * Search for a directory entry directly within dir (without
330 * recursing). Sort dir if necessary. subdirname must be a directory
331 * name (i.e., end in '/'). If mkdir is set, then create the
332 * directory if it is missing; otherwise, return NULL if the desired
333 * directory cannot be found. dir must already be complete.
334 */
335static struct ref_dir *search_for_subdir(struct ref_dir *dir,
336 const char *subdirname, size_t len,
337 int mkdir)
338{
339 int entry_index = search_ref_dir(dir, subdirname, len);
340 struct ref_entry *entry;
341 if (entry_index == -1) {
342 if (!mkdir)
343 return NULL;
344 /*
345 * Since dir is complete, the absence of a subdir
346 * means that the subdir really doesn't exist;
347 * therefore, create an empty record for it but mark
348 * the record complete.
349 */
350 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
351 add_entry_to_dir(dir, entry);
352 } else {
353 entry = dir->entries[entry_index];
354 }
355 return get_ref_dir(entry);
356}
357
358/*
359 * If refname is a reference name, find the ref_dir within the dir
360 * tree that should hold refname. If refname is a directory name
361 * (i.e., ends in '/'), then return that ref_dir itself. dir must
362 * represent the top-level directory and must already be complete.
363 * Sort ref_dirs and recurse into subdirectories as necessary. If
364 * mkdir is set, then create any missing directories; otherwise,
365 * return NULL if the desired directory cannot be found.
366 */
367static struct ref_dir *find_containing_dir(struct ref_dir *dir,
368 const char *refname, int mkdir)
369{
370 const char *slash;
371 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
372 size_t dirnamelen = slash - refname + 1;
373 struct ref_dir *subdir;
374 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
375 if (!subdir) {
376 dir = NULL;
377 break;
378 }
379 dir = subdir;
380 }
381
382 return dir;
383}
384
385/*
386 * Find the value entry with the given name in dir, sorting ref_dirs
387 * and recursing into subdirectories as necessary. If the name is not
388 * found or it corresponds to a directory entry, return NULL.
389 */
390static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
391{
392 int entry_index;
393 struct ref_entry *entry;
394 dir = find_containing_dir(dir, refname, 0);
395 if (!dir)
396 return NULL;
397 entry_index = search_ref_dir(dir, refname, strlen(refname));
398 if (entry_index == -1)
399 return NULL;
400 entry = dir->entries[entry_index];
401 return (entry->flag & REF_DIR) ? NULL : entry;
402}
403
404/*
405 * Remove the entry with the given name from dir, recursing into
406 * subdirectories as necessary. If refname is the name of a directory
407 * (i.e., ends with '/'), then remove the directory and its contents.
408 * If the removal was successful, return the number of entries
409 * remaining in the directory entry that contained the deleted entry.
410 * If the name was not found, return -1. Please note that this
411 * function only deletes the entry from the cache; it does not delete
412 * it from the filesystem or ensure that other cache entries (which
413 * might be symbolic references to the removed entry) are updated.
414 * Nor does it remove any containing dir entries that might be made
415 * empty by the removal. dir must represent the top-level directory
416 * and must already be complete.
417 */
418static int remove_entry(struct ref_dir *dir, const char *refname)
419{
420 int refname_len = strlen(refname);
421 int entry_index;
422 struct ref_entry *entry;
423 int is_dir = refname[refname_len - 1] == '/';
424 if (is_dir) {
425 /*
426 * refname represents a reference directory. Remove
427 * the trailing slash; otherwise we will get the
428 * directory *representing* refname rather than the
429 * one *containing* it.
430 */
431 char *dirname = xmemdupz(refname, refname_len - 1);
432 dir = find_containing_dir(dir, dirname, 0);
433 free(dirname);
434 } else {
435 dir = find_containing_dir(dir, refname, 0);
436 }
437 if (!dir)
438 return -1;
439 entry_index = search_ref_dir(dir, refname, refname_len);
440 if (entry_index == -1)
441 return -1;
442 entry = dir->entries[entry_index];
443
444 memmove(&dir->entries[entry_index],
445 &dir->entries[entry_index + 1],
446 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
447 );
448 dir->nr--;
449 if (dir->sorted > entry_index)
450 dir->sorted--;
451 free_ref_entry(entry);
452 return dir->nr;
453}
454
455/*
456 * Add a ref_entry to the ref_dir (unsorted), recursing into
457 * subdirectories as necessary. dir must represent the top-level
458 * directory. Return 0 on success.
459 */
460static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
461{
462 dir = find_containing_dir(dir, ref->name, 1);
463 if (!dir)
464 return -1;
465 add_entry_to_dir(dir, ref);
466 return 0;
467}
468
469/*
470 * Emit a warning and return true iff ref1 and ref2 have the same name
471 * and the same sha1. Die if they have the same name but different
472 * sha1s.
473 */
474static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
475{
476 if (strcmp(ref1->name, ref2->name))
477 return 0;
478
479 /* Duplicate name; make sure that they don't conflict: */
480
481 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
482 /* This is impossible by construction */
483 die("Reference directory conflict: %s", ref1->name);
484
485 if (oidcmp(&ref1->u.value.oid, &ref2->u.value.oid))
486 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
487
488 warning("Duplicated ref: %s", ref1->name);
489 return 1;
490}
491
492/*
493 * Sort the entries in dir non-recursively (if they are not already
494 * sorted) and remove any duplicate entries.
495 */
496static void sort_ref_dir(struct ref_dir *dir)
497{
498 int i, j;
499 struct ref_entry *last = NULL;
500
501 /*
502 * This check also prevents passing a zero-length array to qsort(),
503 * which is a problem on some platforms.
504 */
505 if (dir->sorted == dir->nr)
506 return;
507
508 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
509
510 /* Remove any duplicates: */
511 for (i = 0, j = 0; j < dir->nr; j++) {
512 struct ref_entry *entry = dir->entries[j];
513 if (last && is_dup_ref(last, entry))
514 free_ref_entry(entry);
515 else
516 last = dir->entries[i++] = entry;
517 }
518 dir->sorted = dir->nr = i;
519}
520
521/* Include broken references in a do_for_each_ref*() iteration: */
522#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
523
524/*
525 * Return true iff the reference described by entry can be resolved to
526 * an object in the database. Emit a warning if the referred-to
527 * object does not exist.
528 */
529static int ref_resolves_to_object(struct ref_entry *entry)
530{
531 if (entry->flag & REF_ISBROKEN)
532 return 0;
533 if (!has_sha1_file(entry->u.value.oid.hash)) {
534 error("%s does not point to a valid object!", entry->name);
535 return 0;
536 }
537 return 1;
538}
539
540/*
541 * current_ref is a performance hack: when iterating over references
542 * using the for_each_ref*() functions, current_ref is set to the
543 * current reference's entry before calling the callback function. If
544 * the callback function calls peel_ref(), then peel_ref() first
545 * checks whether the reference to be peeled is the current reference
546 * (it usually is) and if so, returns that reference's peeled version
547 * if it is available. This avoids a refname lookup in a common case.
548 */
549static struct ref_entry *current_ref;
550
551typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
552
553struct ref_entry_cb {
554 const char *base;
555 int trim;
556 int flags;
557 each_ref_fn *fn;
558 void *cb_data;
559};
560
561/*
562 * Handle one reference in a do_for_each_ref*()-style iteration,
563 * calling an each_ref_fn for each entry.
564 */
565static int do_one_ref(struct ref_entry *entry, void *cb_data)
566{
567 struct ref_entry_cb *data = cb_data;
568 struct ref_entry *old_current_ref;
569 int retval;
570
571 if (!starts_with(entry->name, data->base))
572 return 0;
573
574 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
575 !ref_resolves_to_object(entry))
576 return 0;
577
578 /* Store the old value, in case this is a recursive call: */
579 old_current_ref = current_ref;
580 current_ref = entry;
581 retval = data->fn(entry->name + data->trim, &entry->u.value.oid,
582 entry->flag, data->cb_data);
583 current_ref = old_current_ref;
584 return retval;
585}
586
587/*
588 * Call fn for each reference in dir that has index in the range
589 * offset <= index < dir->nr. Recurse into subdirectories that are in
590 * that index range, sorting them before iterating. This function
591 * does not sort dir itself; it should be sorted beforehand. fn is
592 * called for all references, including broken ones.
593 */
594static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
595 each_ref_entry_fn fn, void *cb_data)
596{
597 int i;
598 assert(dir->sorted == dir->nr);
599 for (i = offset; i < dir->nr; i++) {
600 struct ref_entry *entry = dir->entries[i];
601 int retval;
602 if (entry->flag & REF_DIR) {
603 struct ref_dir *subdir = get_ref_dir(entry);
604 sort_ref_dir(subdir);
605 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
606 } else {
607 retval = fn(entry, cb_data);
608 }
609 if (retval)
610 return retval;
611 }
612 return 0;
613}
614
615/*
616 * Call fn for each reference in the union of dir1 and dir2, in order
617 * by refname. Recurse into subdirectories. If a value entry appears
618 * in both dir1 and dir2, then only process the version that is in
619 * dir2. The input dirs must already be sorted, but subdirs will be
620 * sorted as needed. fn is called for all references, including
621 * broken ones.
622 */
623static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
624 struct ref_dir *dir2,
625 each_ref_entry_fn fn, void *cb_data)
626{
627 int retval;
628 int i1 = 0, i2 = 0;
629
630 assert(dir1->sorted == dir1->nr);
631 assert(dir2->sorted == dir2->nr);
632 while (1) {
633 struct ref_entry *e1, *e2;
634 int cmp;
635 if (i1 == dir1->nr) {
636 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
637 }
638 if (i2 == dir2->nr) {
639 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
640 }
641 e1 = dir1->entries[i1];
642 e2 = dir2->entries[i2];
643 cmp = strcmp(e1->name, e2->name);
644 if (cmp == 0) {
645 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
646 /* Both are directories; descend them in parallel. */
647 struct ref_dir *subdir1 = get_ref_dir(e1);
648 struct ref_dir *subdir2 = get_ref_dir(e2);
649 sort_ref_dir(subdir1);
650 sort_ref_dir(subdir2);
651 retval = do_for_each_entry_in_dirs(
652 subdir1, subdir2, fn, cb_data);
653 i1++;
654 i2++;
655 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
656 /* Both are references; ignore the one from dir1. */
657 retval = fn(e2, cb_data);
658 i1++;
659 i2++;
660 } else {
661 die("conflict between reference and directory: %s",
662 e1->name);
663 }
664 } else {
665 struct ref_entry *e;
666 if (cmp < 0) {
667 e = e1;
668 i1++;
669 } else {
670 e = e2;
671 i2++;
672 }
673 if (e->flag & REF_DIR) {
674 struct ref_dir *subdir = get_ref_dir(e);
675 sort_ref_dir(subdir);
676 retval = do_for_each_entry_in_dir(
677 subdir, 0, fn, cb_data);
678 } else {
679 retval = fn(e, cb_data);
680 }
681 }
682 if (retval)
683 return retval;
684 }
685}
686
687/*
688 * Load all of the refs from the dir into our in-memory cache. The hard work
689 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
690 * through all of the sub-directories. We do not even need to care about
691 * sorting, as traversal order does not matter to us.
692 */
693static void prime_ref_dir(struct ref_dir *dir)
694{
695 int i;
696 for (i = 0; i < dir->nr; i++) {
697 struct ref_entry *entry = dir->entries[i];
698 if (entry->flag & REF_DIR)
699 prime_ref_dir(get_ref_dir(entry));
700 }
701}
702
703struct nonmatching_ref_data {
704 const struct string_list *skip;
705 const char *conflicting_refname;
706};
707
708static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata)
709{
710 struct nonmatching_ref_data *data = vdata;
711
712 if (data->skip && string_list_has_string(data->skip, entry->name))
713 return 0;
714
715 data->conflicting_refname = entry->name;
716 return 1;
717}
718
719/*
720 * Return 0 if a reference named refname could be created without
721 * conflicting with the name of an existing reference in dir.
722 * See verify_refname_available for more information.
723 */
724static int verify_refname_available_dir(const char *refname,
725 const struct string_list *extras,
726 const struct string_list *skip,
727 struct ref_dir *dir,
728 struct strbuf *err)
729{
730 const char *slash;
0845122c 731 const char *extra_refname;
7bd9bcf3
MH
732 int pos;
733 struct strbuf dirname = STRBUF_INIT;
734 int ret = -1;
735
736 /*
737 * For the sake of comments in this function, suppose that
738 * refname is "refs/foo/bar".
739 */
740
741 assert(err);
742
743 strbuf_grow(&dirname, strlen(refname) + 1);
744 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
745 /* Expand dirname to the new prefix, not including the trailing slash: */
746 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
747
748 /*
749 * We are still at a leading dir of the refname (e.g.,
750 * "refs/foo"; if there is a reference with that name,
751 * it is a conflict, *unless* it is in skip.
752 */
753 if (dir) {
754 pos = search_ref_dir(dir, dirname.buf, dirname.len);
755 if (pos >= 0 &&
756 (!skip || !string_list_has_string(skip, dirname.buf))) {
757 /*
758 * We found a reference whose name is
759 * a proper prefix of refname; e.g.,
760 * "refs/foo", and is not in skip.
761 */
762 strbuf_addf(err, "'%s' exists; cannot create '%s'",
763 dirname.buf, refname);
764 goto cleanup;
765 }
766 }
767
768 if (extras && string_list_has_string(extras, dirname.buf) &&
769 (!skip || !string_list_has_string(skip, dirname.buf))) {
770 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
771 refname, dirname.buf);
772 goto cleanup;
773 }
774
775 /*
776 * Otherwise, we can try to continue our search with
777 * the next component. So try to look up the
778 * directory, e.g., "refs/foo/". If we come up empty,
779 * we know there is nothing under this whole prefix,
780 * but even in that case we still have to continue the
781 * search for conflicts with extras.
782 */
783 strbuf_addch(&dirname, '/');
784 if (dir) {
785 pos = search_ref_dir(dir, dirname.buf, dirname.len);
786 if (pos < 0) {
787 /*
788 * There was no directory "refs/foo/",
789 * so there is nothing under this
790 * whole prefix. So there is no need
791 * to continue looking for conflicting
792 * references. But we need to continue
793 * looking for conflicting extras.
794 */
795 dir = NULL;
796 } else {
797 dir = get_ref_dir(dir->entries[pos]);
798 }
799 }
800 }
801
802 /*
803 * We are at the leaf of our refname (e.g., "refs/foo/bar").
804 * There is no point in searching for a reference with that
805 * name, because a refname isn't considered to conflict with
806 * itself. But we still need to check for references whose
807 * names are in the "refs/foo/bar/" namespace, because they
808 * *do* conflict.
809 */
810 strbuf_addstr(&dirname, refname + dirname.len);
811 strbuf_addch(&dirname, '/');
812
813 if (dir) {
814 pos = search_ref_dir(dir, dirname.buf, dirname.len);
815
816 if (pos >= 0) {
817 /*
818 * We found a directory named "$refname/"
819 * (e.g., "refs/foo/bar/"). It is a problem
820 * iff it contains any ref that is not in
821 * "skip".
822 */
823 struct nonmatching_ref_data data;
824
825 data.skip = skip;
826 data.conflicting_refname = NULL;
827 dir = get_ref_dir(dir->entries[pos]);
828 sort_ref_dir(dir);
829 if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) {
830 strbuf_addf(err, "'%s' exists; cannot create '%s'",
831 data.conflicting_refname, refname);
832 goto cleanup;
833 }
834 }
835 }
836
0845122c
DT
837 extra_refname = find_descendant_ref(dirname.buf, extras, skip);
838 if (extra_refname)
839 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
840 refname, extra_refname);
841 else
842 ret = 0;
7bd9bcf3
MH
843
844cleanup:
845 strbuf_release(&dirname);
846 return ret;
847}
848
849struct packed_ref_cache {
850 struct ref_entry *root;
851
852 /*
853 * Count of references to the data structure in this instance,
854 * including the pointer from ref_cache::packed if any. The
855 * data will not be freed as long as the reference count is
856 * nonzero.
857 */
858 unsigned int referrers;
859
860 /*
861 * Iff the packed-refs file associated with this instance is
862 * currently locked for writing, this points at the associated
863 * lock (which is owned by somebody else). The referrer count
864 * is also incremented when the file is locked and decremented
865 * when it is unlocked.
866 */
867 struct lock_file *lock;
868
869 /* The metadata from when this packed-refs cache was read */
870 struct stat_validity validity;
871};
872
873/*
874 * Future: need to be in "struct repository"
875 * when doing a full libification.
876 */
877static struct ref_cache {
878 struct ref_cache *next;
879 struct ref_entry *loose;
880 struct packed_ref_cache *packed;
881 /*
882 * The submodule name, or "" for the main repo. We allocate
883 * length 1 rather than FLEX_ARRAY so that the main ref_cache
884 * is initialized correctly.
885 */
886 char name[1];
887} ref_cache, *submodule_ref_caches;
888
889/* Lock used for the main packed-refs file: */
890static struct lock_file packlock;
891
892/*
893 * Increment the reference count of *packed_refs.
894 */
895static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
896{
897 packed_refs->referrers++;
898}
899
900/*
901 * Decrease the reference count of *packed_refs. If it goes to zero,
902 * free *packed_refs and return true; otherwise return false.
903 */
904static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
905{
906 if (!--packed_refs->referrers) {
907 free_ref_entry(packed_refs->root);
908 stat_validity_clear(&packed_refs->validity);
909 free(packed_refs);
910 return 1;
911 } else {
912 return 0;
913 }
914}
915
916static void clear_packed_ref_cache(struct ref_cache *refs)
917{
918 if (refs->packed) {
919 struct packed_ref_cache *packed_refs = refs->packed;
920
921 if (packed_refs->lock)
922 die("internal error: packed-ref cache cleared while locked");
923 refs->packed = NULL;
924 release_packed_ref_cache(packed_refs);
925 }
926}
927
928static void clear_loose_ref_cache(struct ref_cache *refs)
929{
930 if (refs->loose) {
931 free_ref_entry(refs->loose);
932 refs->loose = NULL;
933 }
934}
935
936static struct ref_cache *create_ref_cache(const char *submodule)
937{
938 int len;
939 struct ref_cache *refs;
940 if (!submodule)
941 submodule = "";
942 len = strlen(submodule) + 1;
943 refs = xcalloc(1, sizeof(struct ref_cache) + len);
944 memcpy(refs->name, submodule, len);
945 return refs;
946}
947
948/*
949 * Return a pointer to a ref_cache for the specified submodule. For
950 * the main repository, use submodule==NULL. The returned structure
951 * will be allocated and initialized but not necessarily populated; it
952 * should not be freed.
953 */
954static struct ref_cache *get_ref_cache(const char *submodule)
955{
956 struct ref_cache *refs;
957
958 if (!submodule || !*submodule)
959 return &ref_cache;
960
961 for (refs = submodule_ref_caches; refs; refs = refs->next)
962 if (!strcmp(submodule, refs->name))
963 return refs;
964
965 refs = create_ref_cache(submodule);
966 refs->next = submodule_ref_caches;
967 submodule_ref_caches = refs;
968 return refs;
969}
970
971/* The length of a peeled reference line in packed-refs, including EOL: */
972#define PEELED_LINE_LENGTH 42
973
974/*
975 * The packed-refs header line that we write out. Perhaps other
976 * traits will be added later. The trailing space is required.
977 */
978static const char PACKED_REFS_HEADER[] =
979 "# pack-refs with: peeled fully-peeled \n";
980
981/*
982 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
983 * Return a pointer to the refname within the line (null-terminated),
984 * or NULL if there was a problem.
985 */
986static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1)
987{
988 const char *ref;
989
990 /*
991 * 42: the answer to everything.
992 *
993 * In this case, it happens to be the answer to
994 * 40 (length of sha1 hex representation)
995 * +1 (space in between hex and name)
996 * +1 (newline at the end of the line)
997 */
998 if (line->len <= 42)
999 return NULL;
1000
1001 if (get_sha1_hex(line->buf, sha1) < 0)
1002 return NULL;
1003 if (!isspace(line->buf[40]))
1004 return NULL;
1005
1006 ref = line->buf + 41;
1007 if (isspace(*ref))
1008 return NULL;
1009
1010 if (line->buf[line->len - 1] != '\n')
1011 return NULL;
1012 line->buf[--line->len] = 0;
1013
1014 return ref;
1015}
1016
1017/*
1018 * Read f, which is a packed-refs file, into dir.
1019 *
1020 * A comment line of the form "# pack-refs with: " may contain zero or
1021 * more traits. We interpret the traits as follows:
1022 *
1023 * No traits:
1024 *
1025 * Probably no references are peeled. But if the file contains a
1026 * peeled value for a reference, we will use it.
1027 *
1028 * peeled:
1029 *
1030 * References under "refs/tags/", if they *can* be peeled, *are*
1031 * peeled in this file. References outside of "refs/tags/" are
1032 * probably not peeled even if they could have been, but if we find
1033 * a peeled value for such a reference we will use it.
1034 *
1035 * fully-peeled:
1036 *
1037 * All references in the file that can be peeled are peeled.
1038 * Inversely (and this is more important), any references in the
1039 * file for which no peeled value is recorded is not peelable. This
1040 * trait should typically be written alongside "peeled" for
1041 * compatibility with older clients, but we do not require it
1042 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1043 */
1044static void read_packed_refs(FILE *f, struct ref_dir *dir)
1045{
1046 struct ref_entry *last = NULL;
1047 struct strbuf line = STRBUF_INIT;
1048 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
1049
1050 while (strbuf_getwholeline(&line, f, '\n') != EOF) {
1051 unsigned char sha1[20];
1052 const char *refname;
1053 const char *traits;
1054
1055 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {
1056 if (strstr(traits, " fully-peeled "))
1057 peeled = PEELED_FULLY;
1058 else if (strstr(traits, " peeled "))
1059 peeled = PEELED_TAGS;
1060 /* perhaps other traits later as well */
1061 continue;
1062 }
1063
1064 refname = parse_ref_line(&line, sha1);
1065 if (refname) {
1066 int flag = REF_ISPACKED;
1067
1068 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1069 if (!refname_is_safe(refname))
1070 die("packed refname is dangerous: %s", refname);
1071 hashclr(sha1);
1072 flag |= REF_BAD_NAME | REF_ISBROKEN;
1073 }
1074 last = create_ref_entry(refname, sha1, flag, 0);
1075 if (peeled == PEELED_FULLY ||
1076 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
1077 last->flag |= REF_KNOWS_PEELED;
1078 add_ref(dir, last);
1079 continue;
1080 }
1081 if (last &&
1082 line.buf[0] == '^' &&
1083 line.len == PEELED_LINE_LENGTH &&
1084 line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&
1085 !get_sha1_hex(line.buf + 1, sha1)) {
1086 hashcpy(last->u.value.peeled.hash, sha1);
1087 /*
1088 * Regardless of what the file header said,
1089 * we definitely know the value of *this*
1090 * reference:
1091 */
1092 last->flag |= REF_KNOWS_PEELED;
1093 }
1094 }
1095
1096 strbuf_release(&line);
1097}
1098
1099/*
1100 * Get the packed_ref_cache for the specified ref_cache, creating it
1101 * if necessary.
1102 */
1103static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
1104{
1105 char *packed_refs_file;
1106
1107 if (*refs->name)
1108 packed_refs_file = git_pathdup_submodule(refs->name, "packed-refs");
1109 else
1110 packed_refs_file = git_pathdup("packed-refs");
1111
1112 if (refs->packed &&
1113 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1114 clear_packed_ref_cache(refs);
1115
1116 if (!refs->packed) {
1117 FILE *f;
1118
1119 refs->packed = xcalloc(1, sizeof(*refs->packed));
1120 acquire_packed_ref_cache(refs->packed);
1121 refs->packed->root = create_dir_entry(refs, "", 0, 0);
1122 f = fopen(packed_refs_file, "r");
1123 if (f) {
1124 stat_validity_update(&refs->packed->validity, fileno(f));
1125 read_packed_refs(f, get_ref_dir(refs->packed->root));
1126 fclose(f);
1127 }
1128 }
1129 free(packed_refs_file);
1130 return refs->packed;
1131}
1132
1133static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1134{
1135 return get_ref_dir(packed_ref_cache->root);
1136}
1137
1138static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1139{
1140 return get_packed_ref_dir(get_packed_ref_cache(refs));
1141}
1142
1143/*
1144 * Add a reference to the in-memory packed reference cache. This may
1145 * only be called while the packed-refs file is locked (see
1146 * lock_packed_refs()). To actually write the packed-refs file, call
1147 * commit_packed_refs().
1148 */
1149static void add_packed_ref(const char *refname, const unsigned char *sha1)
1150{
1151 struct packed_ref_cache *packed_ref_cache =
1152 get_packed_ref_cache(&ref_cache);
1153
1154 if (!packed_ref_cache->lock)
1155 die("internal error: packed refs not locked");
1156 add_ref(get_packed_ref_dir(packed_ref_cache),
1157 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1158}
1159
1160/*
1161 * Read the loose references from the namespace dirname into dir
1162 * (without recursing). dirname must end with '/'. dir must be the
1163 * directory entry corresponding to dirname.
1164 */
1165static void read_loose_refs(const char *dirname, struct ref_dir *dir)
1166{
1167 struct ref_cache *refs = dir->ref_cache;
1168 DIR *d;
1169 struct dirent *de;
1170 int dirnamelen = strlen(dirname);
1171 struct strbuf refname;
1172 struct strbuf path = STRBUF_INIT;
1173 size_t path_baselen;
1174
1175 if (*refs->name)
1176 strbuf_git_path_submodule(&path, refs->name, "%s", dirname);
1177 else
1178 strbuf_git_path(&path, "%s", dirname);
1179 path_baselen = path.len;
1180
1181 d = opendir(path.buf);
1182 if (!d) {
1183 strbuf_release(&path);
1184 return;
1185 }
1186
1187 strbuf_init(&refname, dirnamelen + 257);
1188 strbuf_add(&refname, dirname, dirnamelen);
1189
1190 while ((de = readdir(d)) != NULL) {
1191 unsigned char sha1[20];
1192 struct stat st;
1193 int flag;
1194
1195 if (de->d_name[0] == '.')
1196 continue;
1197 if (ends_with(de->d_name, ".lock"))
1198 continue;
1199 strbuf_addstr(&refname, de->d_name);
1200 strbuf_addstr(&path, de->d_name);
1201 if (stat(path.buf, &st) < 0) {
1202 ; /* silently ignore */
1203 } else if (S_ISDIR(st.st_mode)) {
1204 strbuf_addch(&refname, '/');
1205 add_entry_to_dir(dir,
1206 create_dir_entry(refs, refname.buf,
1207 refname.len, 1));
1208 } else {
1209 int read_ok;
1210
1211 if (*refs->name) {
1212 hashclr(sha1);
1213 flag = 0;
1214 read_ok = !resolve_gitlink_ref(refs->name,
1215 refname.buf, sha1);
1216 } else {
1217 read_ok = !read_ref_full(refname.buf,
1218 RESOLVE_REF_READING,
1219 sha1, &flag);
1220 }
1221
1222 if (!read_ok) {
1223 hashclr(sha1);
1224 flag |= REF_ISBROKEN;
1225 } else if (is_null_sha1(sha1)) {
1226 /*
1227 * It is so astronomically unlikely
1228 * that NULL_SHA1 is the SHA-1 of an
1229 * actual object that we consider its
1230 * appearance in a loose reference
1231 * file to be repo corruption
1232 * (probably due to a software bug).
1233 */
1234 flag |= REF_ISBROKEN;
1235 }
1236
1237 if (check_refname_format(refname.buf,
1238 REFNAME_ALLOW_ONELEVEL)) {
1239 if (!refname_is_safe(refname.buf))
1240 die("loose refname is dangerous: %s", refname.buf);
1241 hashclr(sha1);
1242 flag |= REF_BAD_NAME | REF_ISBROKEN;
1243 }
1244 add_entry_to_dir(dir,
1245 create_ref_entry(refname.buf, sha1, flag, 0));
1246 }
1247 strbuf_setlen(&refname, dirnamelen);
1248 strbuf_setlen(&path, path_baselen);
1249 }
1250 strbuf_release(&refname);
1251 strbuf_release(&path);
1252 closedir(d);
1253}
1254
1255static struct ref_dir *get_loose_refs(struct ref_cache *refs)
1256{
1257 if (!refs->loose) {
1258 /*
1259 * Mark the top-level directory complete because we
1260 * are about to read the only subdirectory that can
1261 * hold references:
1262 */
1263 refs->loose = create_dir_entry(refs, "", 0, 0);
1264 /*
1265 * Create an incomplete entry for "refs/":
1266 */
1267 add_entry_to_dir(get_ref_dir(refs->loose),
1268 create_dir_entry(refs, "refs/", 5, 1));
1269 }
1270 return get_ref_dir(refs->loose);
1271}
1272
1273/* We allow "recursive" symbolic refs. Only within reason, though */
1274#define MAXDEPTH 5
1275#define MAXREFLEN (1024)
1276
1277/*
1278 * Called by resolve_gitlink_ref_recursive() after it failed to read
1279 * from the loose refs in ref_cache refs. Find <refname> in the
1280 * packed-refs file for the submodule.
1281 */
1282static int resolve_gitlink_packed_ref(struct ref_cache *refs,
1283 const char *refname, unsigned char *sha1)
1284{
1285 struct ref_entry *ref;
1286 struct ref_dir *dir = get_packed_refs(refs);
1287
1288 ref = find_ref(dir, refname);
1289 if (ref == NULL)
1290 return -1;
1291
1292 hashcpy(sha1, ref->u.value.oid.hash);
1293 return 0;
1294}
1295
1296static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
1297 const char *refname, unsigned char *sha1,
1298 int recursion)
1299{
1300 int fd, len;
1301 char buffer[128], *p;
1302 char *path;
1303
1304 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
1305 return -1;
1306 path = *refs->name
1307 ? git_pathdup_submodule(refs->name, "%s", refname)
1308 : git_pathdup("%s", refname);
1309 fd = open(path, O_RDONLY);
1310 free(path);
1311 if (fd < 0)
1312 return resolve_gitlink_packed_ref(refs, refname, sha1);
1313
1314 len = read(fd, buffer, sizeof(buffer)-1);
1315 close(fd);
1316 if (len < 0)
1317 return -1;
1318 while (len && isspace(buffer[len-1]))
1319 len--;
1320 buffer[len] = 0;
1321
1322 /* Was it a detached head or an old-fashioned symlink? */
1323 if (!get_sha1_hex(buffer, sha1))
1324 return 0;
1325
1326 /* Symref? */
1327 if (strncmp(buffer, "ref:", 4))
1328 return -1;
1329 p = buffer + 4;
1330 while (isspace(*p))
1331 p++;
1332
1333 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
1334}
1335
1336int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
1337{
1338 int len = strlen(path), retval;
1339 char *submodule;
1340 struct ref_cache *refs;
1341
1342 while (len && path[len-1] == '/')
1343 len--;
1344 if (!len)
1345 return -1;
1346 submodule = xstrndup(path, len);
1347 refs = get_ref_cache(submodule);
1348 free(submodule);
1349
1350 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
1351 return retval;
1352}
1353
1354/*
1355 * Return the ref_entry for the given refname from the packed
1356 * references. If it does not exist, return NULL.
1357 */
1358static struct ref_entry *get_packed_ref(const char *refname)
1359{
1360 return find_ref(get_packed_refs(&ref_cache), refname);
1361}
1362
1363/*
1364 * A loose ref file doesn't exist; check for a packed ref. The
1365 * options are forwarded from resolve_safe_unsafe().
1366 */
1367static int resolve_missing_loose_ref(const char *refname,
1368 int resolve_flags,
1369 unsigned char *sha1,
1370 int *flags)
1371{
1372 struct ref_entry *entry;
1373
1374 /*
1375 * The loose reference file does not exist; check for a packed
1376 * reference.
1377 */
1378 entry = get_packed_ref(refname);
1379 if (entry) {
1380 hashcpy(sha1, entry->u.value.oid.hash);
1381 if (flags)
1382 *flags |= REF_ISPACKED;
1383 return 0;
1384 }
1385 /* The reference is not a packed reference, either. */
1386 if (resolve_flags & RESOLVE_REF_READING) {
1387 errno = ENOENT;
1388 return -1;
1389 } else {
1390 hashclr(sha1);
1391 return 0;
1392 }
1393}
1394
1395/* This function needs to return a meaningful errno on failure */
1396static const char *resolve_ref_1(const char *refname,
1397 int resolve_flags,
1398 unsigned char *sha1,
1399 int *flags,
1400 struct strbuf *sb_refname,
1401 struct strbuf *sb_path,
1402 struct strbuf *sb_contents)
1403{
1404 int depth = MAXDEPTH;
1405 int bad_name = 0;
1406
1407 if (flags)
1408 *flags = 0;
1409
1410 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1411 if (flags)
1412 *flags |= REF_BAD_NAME;
1413
1414 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1415 !refname_is_safe(refname)) {
1416 errno = EINVAL;
1417 return NULL;
1418 }
1419 /*
1420 * dwim_ref() uses REF_ISBROKEN to distinguish between
1421 * missing refs and refs that were present but invalid,
1422 * to complain about the latter to stderr.
1423 *
1424 * We don't know whether the ref exists, so don't set
1425 * REF_ISBROKEN yet.
1426 */
1427 bad_name = 1;
1428 }
1429 for (;;) {
1430 const char *path;
1431 struct stat st;
1432 char *buf;
1433 int fd;
1434
1435 if (--depth < 0) {
1436 errno = ELOOP;
1437 return NULL;
1438 }
1439
1440 strbuf_reset(sb_path);
1441 strbuf_git_path(sb_path, "%s", refname);
1442 path = sb_path->buf;
1443
1444 /*
1445 * We might have to loop back here to avoid a race
1446 * condition: first we lstat() the file, then we try
1447 * to read it as a link or as a file. But if somebody
1448 * changes the type of the file (file <-> directory
1449 * <-> symlink) between the lstat() and reading, then
1450 * we don't want to report that as an error but rather
1451 * try again starting with the lstat().
1452 */
1453 stat_ref:
1454 if (lstat(path, &st) < 0) {
1455 if (errno != ENOENT)
1456 return NULL;
1457 if (resolve_missing_loose_ref(refname, resolve_flags,
1458 sha1, flags))
1459 return NULL;
1460 if (bad_name) {
1461 hashclr(sha1);
1462 if (flags)
1463 *flags |= REF_ISBROKEN;
1464 }
1465 return refname;
1466 }
1467
1468 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1469 if (S_ISLNK(st.st_mode)) {
1470 strbuf_reset(sb_contents);
1471 if (strbuf_readlink(sb_contents, path, 0) < 0) {
1472 if (errno == ENOENT || errno == EINVAL)
1473 /* inconsistent with lstat; retry */
1474 goto stat_ref;
1475 else
1476 return NULL;
1477 }
1478 if (starts_with(sb_contents->buf, "refs/") &&
1479 !check_refname_format(sb_contents->buf, 0)) {
1480 strbuf_swap(sb_refname, sb_contents);
1481 refname = sb_refname->buf;
1482 if (flags)
1483 *flags |= REF_ISSYMREF;
1484 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1485 hashclr(sha1);
1486 return refname;
1487 }
1488 continue;
1489 }
1490 }
1491
1492 /* Is it a directory? */
1493 if (S_ISDIR(st.st_mode)) {
1494 errno = EISDIR;
1495 return NULL;
1496 }
1497
1498 /*
1499 * Anything else, just open it and try to use it as
1500 * a ref
1501 */
1502 fd = open(path, O_RDONLY);
1503 if (fd < 0) {
1504 if (errno == ENOENT)
1505 /* inconsistent with lstat; retry */
1506 goto stat_ref;
1507 else
1508 return NULL;
1509 }
1510 strbuf_reset(sb_contents);
1511 if (strbuf_read(sb_contents, fd, 256) < 0) {
1512 int save_errno = errno;
1513 close(fd);
1514 errno = save_errno;
1515 return NULL;
1516 }
1517 close(fd);
1518 strbuf_rtrim(sb_contents);
1519
1520 /*
1521 * Is it a symbolic ref?
1522 */
1523 if (!starts_with(sb_contents->buf, "ref:")) {
1524 /*
1525 * Please note that FETCH_HEAD has a second
1526 * line containing other data.
1527 */
1528 if (get_sha1_hex(sb_contents->buf, sha1) ||
1529 (sb_contents->buf[40] != '\0' && !isspace(sb_contents->buf[40]))) {
1530 if (flags)
1531 *flags |= REF_ISBROKEN;
1532 errno = EINVAL;
1533 return NULL;
1534 }
1535 if (bad_name) {
1536 hashclr(sha1);
1537 if (flags)
1538 *flags |= REF_ISBROKEN;
1539 }
1540 return refname;
1541 }
1542 if (flags)
1543 *flags |= REF_ISSYMREF;
1544 buf = sb_contents->buf + 4;
1545 while (isspace(*buf))
1546 buf++;
1547 strbuf_reset(sb_refname);
1548 strbuf_addstr(sb_refname, buf);
1549 refname = sb_refname->buf;
1550 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1551 hashclr(sha1);
1552 return refname;
1553 }
1554 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1555 if (flags)
1556 *flags |= REF_ISBROKEN;
1557
1558 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1559 !refname_is_safe(buf)) {
1560 errno = EINVAL;
1561 return NULL;
1562 }
1563 bad_name = 1;
1564 }
1565 }
1566}
1567
1568const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1569 unsigned char *sha1, int *flags)
1570{
1571 static struct strbuf sb_refname = STRBUF_INIT;
1572 struct strbuf sb_contents = STRBUF_INIT;
1573 struct strbuf sb_path = STRBUF_INIT;
1574 const char *ret;
1575
1576 ret = resolve_ref_1(refname, resolve_flags, sha1, flags,
1577 &sb_refname, &sb_path, &sb_contents);
1578 strbuf_release(&sb_path);
1579 strbuf_release(&sb_contents);
1580 return ret;
1581}
1582
1583/*
1584 * Peel the entry (if possible) and return its new peel_status. If
1585 * repeel is true, re-peel the entry even if there is an old peeled
1586 * value that is already stored in it.
1587 *
1588 * It is OK to call this function with a packed reference entry that
1589 * might be stale and might even refer to an object that has since
1590 * been garbage-collected. In such a case, if the entry has
1591 * REF_KNOWS_PEELED then leave the status unchanged and return
1592 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
1593 */
1594static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
1595{
1596 enum peel_status status;
1597
1598 if (entry->flag & REF_KNOWS_PEELED) {
1599 if (repeel) {
1600 entry->flag &= ~REF_KNOWS_PEELED;
1601 oidclr(&entry->u.value.peeled);
1602 } else {
1603 return is_null_oid(&entry->u.value.peeled) ?
1604 PEEL_NON_TAG : PEEL_PEELED;
1605 }
1606 }
1607 if (entry->flag & REF_ISBROKEN)
1608 return PEEL_BROKEN;
1609 if (entry->flag & REF_ISSYMREF)
1610 return PEEL_IS_SYMREF;
1611
1612 status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);
1613 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1614 entry->flag |= REF_KNOWS_PEELED;
1615 return status;
1616}
1617
1618int peel_ref(const char *refname, unsigned char *sha1)
1619{
1620 int flag;
1621 unsigned char base[20];
1622
1623 if (current_ref && (current_ref->name == refname
1624 || !strcmp(current_ref->name, refname))) {
1625 if (peel_entry(current_ref, 0))
1626 return -1;
1627 hashcpy(sha1, current_ref->u.value.peeled.hash);
1628 return 0;
1629 }
1630
1631 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))
1632 return -1;
1633
1634 /*
1635 * If the reference is packed, read its ref_entry from the
1636 * cache in the hope that we already know its peeled value.
1637 * We only try this optimization on packed references because
1638 * (a) forcing the filling of the loose reference cache could
1639 * be expensive and (b) loose references anyway usually do not
1640 * have REF_KNOWS_PEELED.
1641 */
1642 if (flag & REF_ISPACKED) {
1643 struct ref_entry *r = get_packed_ref(refname);
1644 if (r) {
1645 if (peel_entry(r, 0))
1646 return -1;
1647 hashcpy(sha1, r->u.value.peeled.hash);
1648 return 0;
1649 }
1650 }
1651
1652 return peel_object(base, sha1);
1653}
1654
1655/*
1656 * Call fn for each reference in the specified ref_cache, omitting
1657 * references not in the containing_dir of base. fn is called for all
1658 * references, including broken ones. If fn ever returns a non-zero
1659 * value, stop the iteration and return that value; otherwise, return
1660 * 0.
1661 */
1662static int do_for_each_entry(struct ref_cache *refs, const char *base,
1663 each_ref_entry_fn fn, void *cb_data)
1664{
1665 struct packed_ref_cache *packed_ref_cache;
1666 struct ref_dir *loose_dir;
1667 struct ref_dir *packed_dir;
1668 int retval = 0;
1669
1670 /*
1671 * We must make sure that all loose refs are read before accessing the
1672 * packed-refs file; this avoids a race condition in which loose refs
1673 * are migrated to the packed-refs file by a simultaneous process, but
1674 * our in-memory view is from before the migration. get_packed_ref_cache()
1675 * takes care of making sure our view is up to date with what is on
1676 * disk.
1677 */
1678 loose_dir = get_loose_refs(refs);
1679 if (base && *base) {
1680 loose_dir = find_containing_dir(loose_dir, base, 0);
1681 }
1682 if (loose_dir)
1683 prime_ref_dir(loose_dir);
1684
1685 packed_ref_cache = get_packed_ref_cache(refs);
1686 acquire_packed_ref_cache(packed_ref_cache);
1687 packed_dir = get_packed_ref_dir(packed_ref_cache);
1688 if (base && *base) {
1689 packed_dir = find_containing_dir(packed_dir, base, 0);
1690 }
1691
1692 if (packed_dir && loose_dir) {
1693 sort_ref_dir(packed_dir);
1694 sort_ref_dir(loose_dir);
1695 retval = do_for_each_entry_in_dirs(
1696 packed_dir, loose_dir, fn, cb_data);
1697 } else if (packed_dir) {
1698 sort_ref_dir(packed_dir);
1699 retval = do_for_each_entry_in_dir(
1700 packed_dir, 0, fn, cb_data);
1701 } else if (loose_dir) {
1702 sort_ref_dir(loose_dir);
1703 retval = do_for_each_entry_in_dir(
1704 loose_dir, 0, fn, cb_data);
1705 }
1706
1707 release_packed_ref_cache(packed_ref_cache);
1708 return retval;
1709}
1710
1711/*
1712 * Call fn for each reference in the specified ref_cache for which the
1713 * refname begins with base. If trim is non-zero, then trim that many
1714 * characters off the beginning of each refname before passing the
1715 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1716 * broken references in the iteration. If fn ever returns a non-zero
1717 * value, stop the iteration and return that value; otherwise, return
1718 * 0.
1719 */
1720static int do_for_each_ref(struct ref_cache *refs, const char *base,
1721 each_ref_fn fn, int trim, int flags, void *cb_data)
1722{
1723 struct ref_entry_cb data;
1724 data.base = base;
1725 data.trim = trim;
1726 data.flags = flags;
1727 data.fn = fn;
1728 data.cb_data = cb_data;
1729
1730 if (ref_paranoia < 0)
1731 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1732 if (ref_paranoia)
1733 data.flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1734
1735 return do_for_each_entry(refs, base, do_one_ref, &data);
1736}
1737
1738static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1739{
1740 struct object_id oid;
1741 int flag;
1742
1743 if (submodule) {
1744 if (resolve_gitlink_ref(submodule, "HEAD", oid.hash) == 0)
1745 return fn("HEAD", &oid, 0, cb_data);
1746
1747 return 0;
1748 }
1749
1750 if (!read_ref_full("HEAD", RESOLVE_REF_READING, oid.hash, &flag))
1751 return fn("HEAD", &oid, flag, cb_data);
1752
1753 return 0;
1754}
1755
1756int head_ref(each_ref_fn fn, void *cb_data)
1757{
1758 return do_head_ref(NULL, fn, cb_data);
1759}
1760
1761int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1762{
1763 return do_head_ref(submodule, fn, cb_data);
1764}
1765
1766int for_each_ref(each_ref_fn fn, void *cb_data)
1767{
1768 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
1769}
1770
1771int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1772{
1773 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
1774}
1775
1776int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1777{
1778 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
1779}
1780
1781int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1782{
1783 unsigned int flag = 0;
1784
1785 if (broken)
1786 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1787 return do_for_each_ref(&ref_cache, prefix, fn, 0, flag, cb_data);
1788}
1789
1790int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1791 each_ref_fn fn, void *cb_data)
1792{
1793 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
1794}
1795
1796int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1797{
1798 return do_for_each_ref(&ref_cache, git_replace_ref_base, fn,
1799 strlen(git_replace_ref_base), 0, cb_data);
1800}
1801
1802int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1803{
1804 struct strbuf buf = STRBUF_INIT;
1805 int ret;
1806 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1807 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
1808 strbuf_release(&buf);
1809 return ret;
1810}
1811
1812int for_each_rawref(each_ref_fn fn, void *cb_data)
1813{
1814 return do_for_each_ref(&ref_cache, "", fn, 0,
1815 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1816}
1817
1818static void unlock_ref(struct ref_lock *lock)
1819{
1820 /* Do not free lock->lk -- atexit() still looks at them */
1821 if (lock->lk)
1822 rollback_lock_file(lock->lk);
1823 free(lock->ref_name);
1824 free(lock->orig_ref_name);
1825 free(lock);
1826}
1827
1828/*
1829 * Verify that the reference locked by lock has the value old_sha1.
1830 * Fail if the reference doesn't exist and mustexist is set. Return 0
1831 * on success. On error, write an error message to err, set errno, and
1832 * return a negative value.
1833 */
1834static int verify_lock(struct ref_lock *lock,
1835 const unsigned char *old_sha1, int mustexist,
1836 struct strbuf *err)
1837{
1838 assert(err);
1839
1840 if (read_ref_full(lock->ref_name,
1841 mustexist ? RESOLVE_REF_READING : 0,
1842 lock->old_oid.hash, NULL)) {
1843 int save_errno = errno;
1844 strbuf_addf(err, "can't verify ref %s", lock->ref_name);
1845 errno = save_errno;
1846 return -1;
1847 }
1848 if (hashcmp(lock->old_oid.hash, old_sha1)) {
1849 strbuf_addf(err, "ref %s is at %s but expected %s",
1850 lock->ref_name,
1851 sha1_to_hex(lock->old_oid.hash),
1852 sha1_to_hex(old_sha1));
1853 errno = EBUSY;
1854 return -1;
1855 }
1856 return 0;
1857}
1858
1859static int remove_empty_directories(struct strbuf *path)
1860{
1861 /*
1862 * we want to create a file but there is a directory there;
1863 * if that is an empty directory (or a directory that contains
1864 * only empty directories), remove them.
1865 */
1866 return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);
1867}
1868
1869/*
1870 * Locks a ref returning the lock on success and NULL on failure.
1871 * On failure errno is set to something meaningful.
1872 */
1873static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1874 const unsigned char *old_sha1,
1875 const struct string_list *extras,
1876 const struct string_list *skip,
1877 unsigned int flags, int *type_p,
1878 struct strbuf *err)
1879{
1880 struct strbuf ref_file = STRBUF_INIT;
1881 struct strbuf orig_ref_file = STRBUF_INIT;
1882 const char *orig_refname = refname;
1883 struct ref_lock *lock;
1884 int last_errno = 0;
1885 int type, lflags;
1886 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
1887 int resolve_flags = 0;
1888 int attempts_remaining = 3;
1889
1890 assert(err);
1891
1892 lock = xcalloc(1, sizeof(struct ref_lock));
1893
1894 if (mustexist)
1895 resolve_flags |= RESOLVE_REF_READING;
1896 if (flags & REF_DELETING) {
1897 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
1898 if (flags & REF_NODEREF)
1899 resolve_flags |= RESOLVE_REF_NO_RECURSE;
1900 }
1901
1902 refname = resolve_ref_unsafe(refname, resolve_flags,
1903 lock->old_oid.hash, &type);
1904 if (!refname && errno == EISDIR) {
1905 /*
1906 * we are trying to lock foo but we used to
1907 * have foo/bar which now does not exist;
1908 * it is normal for the empty directory 'foo'
1909 * to remain.
1910 */
1911 strbuf_git_path(&orig_ref_file, "%s", orig_refname);
1912 if (remove_empty_directories(&orig_ref_file)) {
1913 last_errno = errno;
1914 if (!verify_refname_available_dir(orig_refname, extras, skip,
1915 get_loose_refs(&ref_cache), err))
1916 strbuf_addf(err, "there are still refs under '%s'",
1917 orig_refname);
1918 goto error_return;
1919 }
1920 refname = resolve_ref_unsafe(orig_refname, resolve_flags,
1921 lock->old_oid.hash, &type);
1922 }
1923 if (type_p)
1924 *type_p = type;
1925 if (!refname) {
1926 last_errno = errno;
1927 if (last_errno != ENOTDIR ||
1928 !verify_refname_available_dir(orig_refname, extras, skip,
1929 get_loose_refs(&ref_cache), err))
1930 strbuf_addf(err, "unable to resolve reference %s: %s",
1931 orig_refname, strerror(last_errno));
1932
1933 goto error_return;
1934 }
1935 /*
1936 * If the ref did not exist and we are creating it, make sure
1937 * there is no existing packed ref whose name begins with our
1938 * refname, nor a packed ref whose name is a proper prefix of
1939 * our refname.
1940 */
1941 if (is_null_oid(&lock->old_oid) &&
1942 verify_refname_available_dir(refname, extras, skip,
1943 get_packed_refs(&ref_cache), err)) {
1944 last_errno = ENOTDIR;
1945 goto error_return;
1946 }
1947
1948 lock->lk = xcalloc(1, sizeof(struct lock_file));
1949
1950 lflags = 0;
1951 if (flags & REF_NODEREF) {
1952 refname = orig_refname;
1953 lflags |= LOCK_NO_DEREF;
1954 }
1955 lock->ref_name = xstrdup(refname);
1956 lock->orig_ref_name = xstrdup(orig_refname);
1957 strbuf_git_path(&ref_file, "%s", refname);
1958
1959 retry:
1960 switch (safe_create_leading_directories_const(ref_file.buf)) {
1961 case SCLD_OK:
1962 break; /* success */
1963 case SCLD_VANISHED:
1964 if (--attempts_remaining > 0)
1965 goto retry;
1966 /* fall through */
1967 default:
1968 last_errno = errno;
1969 strbuf_addf(err, "unable to create directory for %s",
1970 ref_file.buf);
1971 goto error_return;
1972 }
1973
1974 if (hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) < 0) {
1975 last_errno = errno;
1976 if (errno == ENOENT && --attempts_remaining > 0)
1977 /*
1978 * Maybe somebody just deleted one of the
1979 * directories leading to ref_file. Try
1980 * again:
1981 */
1982 goto retry;
1983 else {
1984 unable_to_lock_message(ref_file.buf, errno, err);
1985 goto error_return;
1986 }
1987 }
1988 if (old_sha1 && verify_lock(lock, old_sha1, mustexist, err)) {
1989 last_errno = errno;
1990 goto error_return;
1991 }
1992 goto out;
1993
1994 error_return:
1995 unlock_ref(lock);
1996 lock = NULL;
1997
1998 out:
1999 strbuf_release(&ref_file);
2000 strbuf_release(&orig_ref_file);
2001 errno = last_errno;
2002 return lock;
2003}
2004
2005/*
2006 * Write an entry to the packed-refs file for the specified refname.
2007 * If peeled is non-NULL, write it as the entry's peeled value.
2008 */
2009static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,
2010 unsigned char *peeled)
2011{
2012 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);
2013 if (peeled)
2014 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));
2015}
2016
2017/*
2018 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2019 */
2020static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2021{
2022 enum peel_status peel_status = peel_entry(entry, 0);
2023
2024 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2025 error("internal error: %s is not a valid packed reference!",
2026 entry->name);
2027 write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,
2028 peel_status == PEEL_PEELED ?
2029 entry->u.value.peeled.hash : NULL);
2030 return 0;
2031}
2032
2033/*
2034 * Lock the packed-refs file for writing. Flags is passed to
2035 * hold_lock_file_for_update(). Return 0 on success. On errors, set
2036 * errno appropriately and return a nonzero value.
2037 */
2038static int lock_packed_refs(int flags)
2039{
2040 static int timeout_configured = 0;
2041 static int timeout_value = 1000;
2042
2043 struct packed_ref_cache *packed_ref_cache;
2044
2045 if (!timeout_configured) {
2046 git_config_get_int("core.packedrefstimeout", &timeout_value);
2047 timeout_configured = 1;
2048 }
2049
2050 if (hold_lock_file_for_update_timeout(
2051 &packlock, git_path("packed-refs"),
2052 flags, timeout_value) < 0)
2053 return -1;
2054 /*
2055 * Get the current packed-refs while holding the lock. If the
2056 * packed-refs file has been modified since we last read it,
2057 * this will automatically invalidate the cache and re-read
2058 * the packed-refs file.
2059 */
2060 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2061 packed_ref_cache->lock = &packlock;
2062 /* Increment the reference count to prevent it from being freed: */
2063 acquire_packed_ref_cache(packed_ref_cache);
2064 return 0;
2065}
2066
2067/*
2068 * Write the current version of the packed refs cache from memory to
2069 * disk. The packed-refs file must already be locked for writing (see
2070 * lock_packed_refs()). Return zero on success. On errors, set errno
2071 * and return a nonzero value
2072 */
2073static int commit_packed_refs(void)
2074{
2075 struct packed_ref_cache *packed_ref_cache =
2076 get_packed_ref_cache(&ref_cache);
2077 int error = 0;
2078 int save_errno = 0;
2079 FILE *out;
2080
2081 if (!packed_ref_cache->lock)
2082 die("internal error: packed-refs not locked");
2083
2084 out = fdopen_lock_file(packed_ref_cache->lock, "w");
2085 if (!out)
2086 die_errno("unable to fdopen packed-refs descriptor");
2087
2088 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);
2089 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2090 0, write_packed_entry_fn, out);
2091
2092 if (commit_lock_file(packed_ref_cache->lock)) {
2093 save_errno = errno;
2094 error = -1;
2095 }
2096 packed_ref_cache->lock = NULL;
2097 release_packed_ref_cache(packed_ref_cache);
2098 errno = save_errno;
2099 return error;
2100}
2101
2102/*
2103 * Rollback the lockfile for the packed-refs file, and discard the
2104 * in-memory packed reference cache. (The packed-refs file will be
2105 * read anew if it is needed again after this function is called.)
2106 */
2107static void rollback_packed_refs(void)
2108{
2109 struct packed_ref_cache *packed_ref_cache =
2110 get_packed_ref_cache(&ref_cache);
2111
2112 if (!packed_ref_cache->lock)
2113 die("internal error: packed-refs not locked");
2114 rollback_lock_file(packed_ref_cache->lock);
2115 packed_ref_cache->lock = NULL;
2116 release_packed_ref_cache(packed_ref_cache);
2117 clear_packed_ref_cache(&ref_cache);
2118}
2119
2120struct ref_to_prune {
2121 struct ref_to_prune *next;
2122 unsigned char sha1[20];
2123 char name[FLEX_ARRAY];
2124};
2125
2126struct pack_refs_cb_data {
2127 unsigned int flags;
2128 struct ref_dir *packed_refs;
2129 struct ref_to_prune *ref_to_prune;
2130};
2131
2132/*
2133 * An each_ref_entry_fn that is run over loose references only. If
2134 * the loose reference can be packed, add an entry in the packed ref
2135 * cache. If the reference should be pruned, also add it to
2136 * ref_to_prune in the pack_refs_cb_data.
2137 */
2138static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
2139{
2140 struct pack_refs_cb_data *cb = cb_data;
2141 enum peel_status peel_status;
2142 struct ref_entry *packed_entry;
2143 int is_tag_ref = starts_with(entry->name, "refs/tags/");
2144
2145 /* Do not pack per-worktree refs: */
2146 if (ref_type(entry->name) != REF_TYPE_NORMAL)
2147 return 0;
2148
2149 /* ALWAYS pack tags */
2150 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
2151 return 0;
2152
2153 /* Do not pack symbolic or broken refs: */
2154 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2155 return 0;
2156
2157 /* Add a packed ref cache entry equivalent to the loose entry. */
2158 peel_status = peel_entry(entry, 1);
2159 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2160 die("internal error peeling reference %s (%s)",
2161 entry->name, oid_to_hex(&entry->u.value.oid));
2162 packed_entry = find_ref(cb->packed_refs, entry->name);
2163 if (packed_entry) {
2164 /* Overwrite existing packed entry with info from loose entry */
2165 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2166 oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);
2167 } else {
2168 packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash,
2169 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2170 add_ref(cb->packed_refs, packed_entry);
2171 }
2172 oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);
2173
2174 /* Schedule the loose reference for pruning if requested. */
2175 if ((cb->flags & PACK_REFS_PRUNE)) {
2176 int namelen = strlen(entry->name) + 1;
2177 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
2178 hashcpy(n->sha1, entry->u.value.oid.hash);
2179 memcpy(n->name, entry->name, namelen); /* includes NUL */
2180 n->next = cb->ref_to_prune;
2181 cb->ref_to_prune = n;
2182 }
2183 return 0;
2184}
2185
2186/*
2187 * Remove empty parents, but spare refs/ and immediate subdirs.
2188 * Note: munges *name.
2189 */
2190static void try_remove_empty_parents(char *name)
2191{
2192 char *p, *q;
2193 int i;
2194 p = name;
2195 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2196 while (*p && *p != '/')
2197 p++;
2198 /* tolerate duplicate slashes; see check_refname_format() */
2199 while (*p == '/')
2200 p++;
2201 }
2202 for (q = p; *q; q++)
2203 ;
2204 while (1) {
2205 while (q > p && *q != '/')
2206 q--;
2207 while (q > p && *(q-1) == '/')
2208 q--;
2209 if (q == p)
2210 break;
2211 *q = '\0';
2212 if (rmdir(git_path("%s", name)))
2213 break;
2214 }
2215}
2216
2217/* make sure nobody touched the ref, and unlink */
2218static void prune_ref(struct ref_to_prune *r)
2219{
2220 struct ref_transaction *transaction;
2221 struct strbuf err = STRBUF_INIT;
2222
2223 if (check_refname_format(r->name, 0))
2224 return;
2225
2226 transaction = ref_transaction_begin(&err);
2227 if (!transaction ||
2228 ref_transaction_delete(transaction, r->name, r->sha1,
2229 REF_ISPRUNING, NULL, &err) ||
2230 ref_transaction_commit(transaction, &err)) {
2231 ref_transaction_free(transaction);
2232 error("%s", err.buf);
2233 strbuf_release(&err);
2234 return;
2235 }
2236 ref_transaction_free(transaction);
2237 strbuf_release(&err);
2238 try_remove_empty_parents(r->name);
2239}
2240
2241static void prune_refs(struct ref_to_prune *r)
2242{
2243 while (r) {
2244 prune_ref(r);
2245 r = r->next;
2246 }
2247}
2248
2249int pack_refs(unsigned int flags)
2250{
2251 struct pack_refs_cb_data cbdata;
2252
2253 memset(&cbdata, 0, sizeof(cbdata));
2254 cbdata.flags = flags;
2255
2256 lock_packed_refs(LOCK_DIE_ON_ERROR);
2257 cbdata.packed_refs = get_packed_refs(&ref_cache);
2258
2259 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2260 pack_if_possible_fn, &cbdata);
2261
2262 if (commit_packed_refs())
2263 die_errno("unable to overwrite old ref-pack file");
2264
2265 prune_refs(cbdata.ref_to_prune);
2266 return 0;
2267}
2268
2269/*
2270 * Rewrite the packed-refs file, omitting any refs listed in
2271 * 'refnames'. On error, leave packed-refs unchanged, write an error
2272 * message to 'err', and return a nonzero value.
2273 *
2274 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.
2275 */
2276static int repack_without_refs(struct string_list *refnames, struct strbuf *err)
2277{
2278 struct ref_dir *packed;
2279 struct string_list_item *refname;
2280 int ret, needs_repacking = 0, removed = 0;
2281
2282 assert(err);
2283
2284 /* Look for a packed ref */
2285 for_each_string_list_item(refname, refnames) {
2286 if (get_packed_ref(refname->string)) {
2287 needs_repacking = 1;
2288 break;
2289 }
2290 }
2291
2292 /* Avoid locking if we have nothing to do */
2293 if (!needs_repacking)
2294 return 0; /* no refname exists in packed refs */
2295
2296 if (lock_packed_refs(0)) {
2297 unable_to_lock_message(git_path("packed-refs"), errno, err);
2298 return -1;
2299 }
2300 packed = get_packed_refs(&ref_cache);
2301
2302 /* Remove refnames from the cache */
2303 for_each_string_list_item(refname, refnames)
2304 if (remove_entry(packed, refname->string) != -1)
2305 removed = 1;
2306 if (!removed) {
2307 /*
2308 * All packed entries disappeared while we were
2309 * acquiring the lock.
2310 */
2311 rollback_packed_refs();
2312 return 0;
2313 }
2314
2315 /* Write what remains */
2316 ret = commit_packed_refs();
2317 if (ret)
2318 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",
2319 strerror(errno));
2320 return ret;
2321}
2322
2323static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)
2324{
2325 assert(err);
2326
2327 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
2328 /*
2329 * loose. The loose file name is the same as the
2330 * lockfile name, minus ".lock":
2331 */
2332 char *loose_filename = get_locked_file_path(lock->lk);
2333 int res = unlink_or_msg(loose_filename, err);
2334 free(loose_filename);
2335 if (res)
2336 return 1;
2337 }
2338 return 0;
2339}
2340
2341int delete_refs(struct string_list *refnames)
2342{
2343 struct strbuf err = STRBUF_INIT;
2344 int i, result = 0;
2345
2346 if (!refnames->nr)
2347 return 0;
2348
2349 result = repack_without_refs(refnames, &err);
2350 if (result) {
2351 /*
2352 * If we failed to rewrite the packed-refs file, then
2353 * it is unsafe to try to remove loose refs, because
2354 * doing so might expose an obsolete packed value for
2355 * a reference that might even point at an object that
2356 * has been garbage collected.
2357 */
2358 if (refnames->nr == 1)
2359 error(_("could not delete reference %s: %s"),
2360 refnames->items[0].string, err.buf);
2361 else
2362 error(_("could not delete references: %s"), err.buf);
2363
2364 goto out;
2365 }
2366
2367 for (i = 0; i < refnames->nr; i++) {
2368 const char *refname = refnames->items[i].string;
2369
2370 if (delete_ref(refname, NULL, 0))
2371 result |= error(_("could not remove reference %s"), refname);
2372 }
2373
2374out:
2375 strbuf_release(&err);
2376 return result;
2377}
2378
2379/*
2380 * People using contrib's git-new-workdir have .git/logs/refs ->
2381 * /some/other/path/.git/logs/refs, and that may live on another device.
2382 *
2383 * IOW, to avoid cross device rename errors, the temporary renamed log must
2384 * live into logs/refs.
2385 */
2386#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2387
2388static int rename_tmp_log(const char *newrefname)
2389{
2390 int attempts_remaining = 4;
2391 struct strbuf path = STRBUF_INIT;
2392 int ret = -1;
2393
2394 retry:
2395 strbuf_reset(&path);
2396 strbuf_git_path(&path, "logs/%s", newrefname);
2397 switch (safe_create_leading_directories_const(path.buf)) {
2398 case SCLD_OK:
2399 break; /* success */
2400 case SCLD_VANISHED:
2401 if (--attempts_remaining > 0)
2402 goto retry;
2403 /* fall through */
2404 default:
2405 error("unable to create directory for %s", newrefname);
2406 goto out;
2407 }
2408
2409 if (rename(git_path(TMP_RENAMED_LOG), path.buf)) {
2410 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
2411 /*
2412 * rename(a, b) when b is an existing
2413 * directory ought to result in ISDIR, but
2414 * Solaris 5.8 gives ENOTDIR. Sheesh.
2415 */
2416 if (remove_empty_directories(&path)) {
2417 error("Directory not empty: logs/%s", newrefname);
2418 goto out;
2419 }
2420 goto retry;
2421 } else if (errno == ENOENT && --attempts_remaining > 0) {
2422 /*
2423 * Maybe another process just deleted one of
2424 * the directories in the path to newrefname.
2425 * Try again from the beginning.
2426 */
2427 goto retry;
2428 } else {
2429 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2430 newrefname, strerror(errno));
2431 goto out;
2432 }
2433 }
2434 ret = 0;
2435out:
2436 strbuf_release(&path);
2437 return ret;
2438}
2439
2440int verify_refname_available(const char *newname,
2441 struct string_list *extras,
2442 struct string_list *skip,
2443 struct strbuf *err)
2444{
2445 struct ref_dir *packed_refs = get_packed_refs(&ref_cache);
2446 struct ref_dir *loose_refs = get_loose_refs(&ref_cache);
2447
2448 if (verify_refname_available_dir(newname, extras, skip,
2449 packed_refs, err) ||
2450 verify_refname_available_dir(newname, extras, skip,
2451 loose_refs, err))
2452 return -1;
2453
2454 return 0;
2455}
2456
7bd9bcf3
MH
2457static int write_ref_to_lockfile(struct ref_lock *lock,
2458 const unsigned char *sha1, struct strbuf *err);
2459static int commit_ref_update(struct ref_lock *lock,
2460 const unsigned char *sha1, const char *logmsg,
2461 int flags, struct strbuf *err);
2462
2463int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
2464{
2465 unsigned char sha1[20], orig_sha1[20];
2466 int flag = 0, logmoved = 0;
2467 struct ref_lock *lock;
2468 struct stat loginfo;
2469 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
2470 const char *symref = NULL;
2471 struct strbuf err = STRBUF_INIT;
2472
2473 if (log && S_ISLNK(loginfo.st_mode))
2474 return error("reflog for %s is a symlink", oldrefname);
2475
2476 symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,
2477 orig_sha1, &flag);
2478 if (flag & REF_ISSYMREF)
2479 return error("refname %s is a symbolic ref, renaming it is not supported",
2480 oldrefname);
2481 if (!symref)
2482 return error("refname %s not found", oldrefname);
2483
2484 if (!rename_ref_available(oldrefname, newrefname))
2485 return 1;
2486
2487 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
2488 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
2489 oldrefname, strerror(errno));
2490
2491 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2492 error("unable to delete old %s", oldrefname);
2493 goto rollback;
2494 }
2495
2496 if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&
2497 delete_ref(newrefname, sha1, REF_NODEREF)) {
2498 if (errno==EISDIR) {
2499 struct strbuf path = STRBUF_INIT;
2500 int result;
2501
2502 strbuf_git_path(&path, "%s", newrefname);
2503 result = remove_empty_directories(&path);
2504 strbuf_release(&path);
2505
2506 if (result) {
2507 error("Directory not empty: %s", newrefname);
2508 goto rollback;
2509 }
2510 } else {
2511 error("unable to delete existing %s", newrefname);
2512 goto rollback;
2513 }
2514 }
2515
2516 if (log && rename_tmp_log(newrefname))
2517 goto rollback;
2518
2519 logmoved = log;
2520
2521 lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, 0, NULL, &err);
2522 if (!lock) {
2523 error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);
2524 strbuf_release(&err);
2525 goto rollback;
2526 }
2527 hashcpy(lock->old_oid.hash, orig_sha1);
2528
2529 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||
2530 commit_ref_update(lock, orig_sha1, logmsg, 0, &err)) {
2531 error("unable to write current sha1 into %s: %s", newrefname, err.buf);
2532 strbuf_release(&err);
2533 goto rollback;
2534 }
2535
2536 return 0;
2537
2538 rollback:
2539 lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, 0, NULL, &err);
2540 if (!lock) {
2541 error("unable to lock %s for rollback: %s", oldrefname, err.buf);
2542 strbuf_release(&err);
2543 goto rollbacklog;
2544 }
2545
2546 flag = log_all_ref_updates;
2547 log_all_ref_updates = 0;
2548 if (write_ref_to_lockfile(lock, orig_sha1, &err) ||
2549 commit_ref_update(lock, orig_sha1, NULL, 0, &err)) {
2550 error("unable to write current sha1 into %s: %s", oldrefname, err.buf);
2551 strbuf_release(&err);
2552 }
2553 log_all_ref_updates = flag;
2554
2555 rollbacklog:
2556 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
2557 error("unable to restore logfile %s from %s: %s",
2558 oldrefname, newrefname, strerror(errno));
2559 if (!logmoved && log &&
2560 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
2561 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
2562 oldrefname, strerror(errno));
2563
2564 return 1;
2565}
2566
2567static int close_ref(struct ref_lock *lock)
2568{
2569 if (close_lock_file(lock->lk))
2570 return -1;
2571 return 0;
2572}
2573
2574static int commit_ref(struct ref_lock *lock)
2575{
2576 if (commit_lock_file(lock->lk))
2577 return -1;
2578 return 0;
2579}
2580
2581/*
2582 * Create a reflog for a ref. If force_create = 0, the reflog will
2583 * only be created for certain refs (those for which
2584 * should_autocreate_reflog returns non-zero. Otherwise, create it
2585 * regardless of the ref name. Fill in *err and return -1 on failure.
2586 */
2587static int log_ref_setup(const char *refname, struct strbuf *logfile, struct strbuf *err, int force_create)
2588{
2589 int logfd, oflags = O_APPEND | O_WRONLY;
2590
2591 strbuf_git_path(logfile, "logs/%s", refname);
2592 if (force_create || should_autocreate_reflog(refname)) {
2593 if (safe_create_leading_directories(logfile->buf) < 0) {
2594 strbuf_addf(err, "unable to create directory for %s: "
2595 "%s", logfile->buf, strerror(errno));
2596 return -1;
2597 }
2598 oflags |= O_CREAT;
2599 }
2600
2601 logfd = open(logfile->buf, oflags, 0666);
2602 if (logfd < 0) {
2603 if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))
2604 return 0;
2605
2606 if (errno == EISDIR) {
2607 if (remove_empty_directories(logfile)) {
2608 strbuf_addf(err, "There are still logs under "
2609 "'%s'", logfile->buf);
2610 return -1;
2611 }
2612 logfd = open(logfile->buf, oflags, 0666);
2613 }
2614
2615 if (logfd < 0) {
2616 strbuf_addf(err, "unable to append to %s: %s",
2617 logfile->buf, strerror(errno));
2618 return -1;
2619 }
2620 }
2621
2622 adjust_shared_perm(logfile->buf);
2623 close(logfd);
2624 return 0;
2625}
2626
2627
2628int safe_create_reflog(const char *refname, int force_create, struct strbuf *err)
2629{
2630 int ret;
2631 struct strbuf sb = STRBUF_INIT;
2632
2633 ret = log_ref_setup(refname, &sb, err, force_create);
2634 strbuf_release(&sb);
2635 return ret;
2636}
2637
2638static int log_ref_write_fd(int fd, const unsigned char *old_sha1,
2639 const unsigned char *new_sha1,
2640 const char *committer, const char *msg)
2641{
2642 int msglen, written;
2643 unsigned maxlen, len;
2644 char *logrec;
2645
2646 msglen = msg ? strlen(msg) : 0;
2647 maxlen = strlen(committer) + msglen + 100;
2648 logrec = xmalloc(maxlen);
2649 len = xsnprintf(logrec, maxlen, "%s %s %s\n",
2650 sha1_to_hex(old_sha1),
2651 sha1_to_hex(new_sha1),
2652 committer);
2653 if (msglen)
2654 len += copy_reflog_msg(logrec + len - 1, msg) - 1;
2655
2656 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;
2657 free(logrec);
2658 if (written != len)
2659 return -1;
2660
2661 return 0;
2662}
2663
2664static int log_ref_write_1(const char *refname, const unsigned char *old_sha1,
2665 const unsigned char *new_sha1, const char *msg,
2666 struct strbuf *logfile, int flags,
2667 struct strbuf *err)
2668{
2669 int logfd, result, oflags = O_APPEND | O_WRONLY;
2670
2671 if (log_all_ref_updates < 0)
2672 log_all_ref_updates = !is_bare_repository();
2673
2674 result = log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);
2675
2676 if (result)
2677 return result;
2678
2679 logfd = open(logfile->buf, oflags);
2680 if (logfd < 0)
2681 return 0;
2682 result = log_ref_write_fd(logfd, old_sha1, new_sha1,
2683 git_committer_info(0), msg);
2684 if (result) {
2685 strbuf_addf(err, "unable to append to %s: %s", logfile->buf,
2686 strerror(errno));
2687 close(logfd);
2688 return -1;
2689 }
2690 if (close(logfd)) {
2691 strbuf_addf(err, "unable to append to %s: %s", logfile->buf,
2692 strerror(errno));
2693 return -1;
2694 }
2695 return 0;
2696}
2697
2698static int log_ref_write(const char *refname, const unsigned char *old_sha1,
2699 const unsigned char *new_sha1, const char *msg,
2700 int flags, struct strbuf *err)
5f3c3a4e
DT
2701{
2702 return files_log_ref_write(refname, old_sha1, new_sha1, msg, flags,
2703 err);
2704}
2705
2706int files_log_ref_write(const char *refname, const unsigned char *old_sha1,
2707 const unsigned char *new_sha1, const char *msg,
2708 int flags, struct strbuf *err)
7bd9bcf3
MH
2709{
2710 struct strbuf sb = STRBUF_INIT;
2711 int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,
2712 err);
2713 strbuf_release(&sb);
2714 return ret;
2715}
2716
2717/*
2718 * Write sha1 into the open lockfile, then close the lockfile. On
2719 * errors, rollback the lockfile, fill in *err and
2720 * return -1.
2721 */
2722static int write_ref_to_lockfile(struct ref_lock *lock,
2723 const unsigned char *sha1, struct strbuf *err)
2724{
2725 static char term = '\n';
2726 struct object *o;
2727 int fd;
2728
2729 o = parse_object(sha1);
2730 if (!o) {
2731 strbuf_addf(err,
2732 "Trying to write ref %s with nonexistent object %s",
2733 lock->ref_name, sha1_to_hex(sha1));
2734 unlock_ref(lock);
2735 return -1;
2736 }
2737 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2738 strbuf_addf(err,
2739 "Trying to write non-commit object %s to branch %s",
2740 sha1_to_hex(sha1), lock->ref_name);
2741 unlock_ref(lock);
2742 return -1;
2743 }
2744 fd = get_lock_file_fd(lock->lk);
2745 if (write_in_full(fd, sha1_to_hex(sha1), 40) != 40 ||
2746 write_in_full(fd, &term, 1) != 1 ||
2747 close_ref(lock) < 0) {
2748 strbuf_addf(err,
2749 "Couldn't write %s", get_lock_file_path(lock->lk));
2750 unlock_ref(lock);
2751 return -1;
2752 }
2753 return 0;
2754}
2755
2756/*
2757 * Commit a change to a loose reference that has already been written
2758 * to the loose reference lockfile. Also update the reflogs if
2759 * necessary, using the specified lockmsg (which can be NULL).
2760 */
2761static int commit_ref_update(struct ref_lock *lock,
2762 const unsigned char *sha1, const char *logmsg,
2763 int flags, struct strbuf *err)
2764{
2765 clear_loose_ref_cache(&ref_cache);
2766 if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) < 0 ||
2767 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2768 log_ref_write(lock->orig_ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) < 0)) {
2769 char *old_msg = strbuf_detach(err, NULL);
2770 strbuf_addf(err, "Cannot update the ref '%s': %s",
2771 lock->ref_name, old_msg);
2772 free(old_msg);
2773 unlock_ref(lock);
2774 return -1;
2775 }
2776 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2777 /*
2778 * Special hack: If a branch is updated directly and HEAD
2779 * points to it (may happen on the remote side of a push
2780 * for example) then logically the HEAD reflog should be
2781 * updated too.
2782 * A generic solution implies reverse symref information,
2783 * but finding all symrefs pointing to the given branch
2784 * would be rather costly for this rare event (the direct
2785 * update of a branch) to be worth it. So let's cheat and
2786 * check with HEAD only which should cover 99% of all usage
2787 * scenarios (even 100% of the default ones).
2788 */
2789 unsigned char head_sha1[20];
2790 int head_flag;
2791 const char *head_ref;
2792 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
2793 head_sha1, &head_flag);
2794 if (head_ref && (head_flag & REF_ISSYMREF) &&
2795 !strcmp(head_ref, lock->ref_name)) {
2796 struct strbuf log_err = STRBUF_INIT;
2797 if (log_ref_write("HEAD", lock->old_oid.hash, sha1,
2798 logmsg, 0, &log_err)) {
2799 error("%s", log_err.buf);
2800 strbuf_release(&log_err);
2801 }
2802 }
2803 }
2804 if (commit_ref(lock)) {
2805 error("Couldn't set %s", lock->ref_name);
2806 unlock_ref(lock);
2807 return -1;
2808 }
2809
2810 unlock_ref(lock);
2811 return 0;
2812}
2813
370e5ad6 2814static int create_ref_symlink(struct ref_lock *lock, const char *target)
7bd9bcf3 2815{
370e5ad6 2816 int ret = -1;
7bd9bcf3 2817#ifndef NO_SYMLINK_HEAD
370e5ad6
JK
2818 char *ref_path = get_locked_file_path(lock->lk);
2819 unlink(ref_path);
2820 ret = symlink(target, ref_path);
2821 free(ref_path);
2822
2823 if (ret)
7bd9bcf3 2824 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
7bd9bcf3 2825#endif
370e5ad6
JK
2826 return ret;
2827}
7bd9bcf3 2828
370e5ad6
JK
2829static void update_symref_reflog(struct ref_lock *lock, const char *refname,
2830 const char *target, const char *logmsg)
2831{
2832 struct strbuf err = STRBUF_INIT;
2833 unsigned char new_sha1[20];
b9badadd 2834 if (logmsg && !read_ref(target, new_sha1) &&
370e5ad6 2835 log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg, 0, &err)) {
7bd9bcf3
MH
2836 error("%s", err.buf);
2837 strbuf_release(&err);
2838 }
370e5ad6 2839}
7bd9bcf3 2840
370e5ad6
JK
2841static int create_symref_locked(struct ref_lock *lock, const char *refname,
2842 const char *target, const char *logmsg)
2843{
2844 if (prefer_symlink_refs && !create_ref_symlink(lock, target)) {
2845 update_symref_reflog(lock, refname, target, logmsg);
2846 return 0;
2847 }
2848
2849 if (!fdopen_lock_file(lock->lk, "w"))
2850 return error("unable to fdopen %s: %s",
2851 lock->lk->tempfile.filename.buf, strerror(errno));
2852
396da8f7
JK
2853 update_symref_reflog(lock, refname, target, logmsg);
2854
370e5ad6
JK
2855 /* no error check; commit_ref will check ferror */
2856 fprintf(lock->lk->tempfile.fp, "ref: %s\n", target);
2857 if (commit_ref(lock) < 0)
2858 return error("unable to write symref for %s: %s", refname,
2859 strerror(errno));
7bd9bcf3
MH
2860 return 0;
2861}
2862
370e5ad6
JK
2863int create_symref(const char *refname, const char *target, const char *logmsg)
2864{
2865 struct strbuf err = STRBUF_INIT;
2866 struct ref_lock *lock;
2867 int ret;
2868
2869 lock = lock_ref_sha1_basic(refname, NULL, NULL, NULL, REF_NODEREF, NULL,
2870 &err);
2871 if (!lock) {
2872 error("%s", err.buf);
2873 strbuf_release(&err);
2874 return -1;
2875 }
2876
2877 ret = create_symref_locked(lock, refname, target, logmsg);
2878 unlock_ref(lock);
2879 return ret;
2880}
2881
7bd9bcf3
MH
2882int reflog_exists(const char *refname)
2883{
2884 struct stat st;
2885
2886 return !lstat(git_path("logs/%s", refname), &st) &&
2887 S_ISREG(st.st_mode);
2888}
2889
2890int delete_reflog(const char *refname)
2891{
2892 return remove_path(git_path("logs/%s", refname));
2893}
2894
2895static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
2896{
2897 unsigned char osha1[20], nsha1[20];
2898 char *email_end, *message;
2899 unsigned long timestamp;
2900 int tz;
2901
2902 /* old SP new SP name <email> SP time TAB msg LF */
2903 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
2904 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
2905 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
2906 !(email_end = strchr(sb->buf + 82, '>')) ||
2907 email_end[1] != ' ' ||
2908 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2909 !message || message[0] != ' ' ||
2910 (message[1] != '+' && message[1] != '-') ||
2911 !isdigit(message[2]) || !isdigit(message[3]) ||
2912 !isdigit(message[4]) || !isdigit(message[5]))
2913 return 0; /* corrupt? */
2914 email_end[1] = '\0';
2915 tz = strtol(message + 1, NULL, 10);
2916 if (message[6] != '\t')
2917 message += 6;
2918 else
2919 message += 7;
2920 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
2921}
2922
2923static char *find_beginning_of_line(char *bob, char *scan)
2924{
2925 while (bob < scan && *(--scan) != '\n')
2926 ; /* keep scanning backwards */
2927 /*
2928 * Return either beginning of the buffer, or LF at the end of
2929 * the previous line.
2930 */
2931 return scan;
2932}
2933
2934int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
2935{
2936 struct strbuf sb = STRBUF_INIT;
2937 FILE *logfp;
2938 long pos;
2939 int ret = 0, at_tail = 1;
2940
2941 logfp = fopen(git_path("logs/%s", refname), "r");
2942 if (!logfp)
2943 return -1;
2944
2945 /* Jump to the end */
2946 if (fseek(logfp, 0, SEEK_END) < 0)
2947 return error("cannot seek back reflog for %s: %s",
2948 refname, strerror(errno));
2949 pos = ftell(logfp);
2950 while (!ret && 0 < pos) {
2951 int cnt;
2952 size_t nread;
2953 char buf[BUFSIZ];
2954 char *endp, *scanp;
2955
2956 /* Fill next block from the end */
2957 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
2958 if (fseek(logfp, pos - cnt, SEEK_SET))
2959 return error("cannot seek back reflog for %s: %s",
2960 refname, strerror(errno));
2961 nread = fread(buf, cnt, 1, logfp);
2962 if (nread != 1)
2963 return error("cannot read %d bytes from reflog for %s: %s",
2964 cnt, refname, strerror(errno));
2965 pos -= cnt;
2966
2967 scanp = endp = buf + cnt;
2968 if (at_tail && scanp[-1] == '\n')
2969 /* Looking at the final LF at the end of the file */
2970 scanp--;
2971 at_tail = 0;
2972
2973 while (buf < scanp) {
2974 /*
2975 * terminating LF of the previous line, or the beginning
2976 * of the buffer.
2977 */
2978 char *bp;
2979
2980 bp = find_beginning_of_line(buf, scanp);
2981
2982 if (*bp == '\n') {
2983 /*
2984 * The newline is the end of the previous line,
2985 * so we know we have complete line starting
2986 * at (bp + 1). Prefix it onto any prior data
2987 * we collected for the line and process it.
2988 */
2989 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
2990 scanp = bp;
2991 endp = bp + 1;
2992 ret = show_one_reflog_ent(&sb, fn, cb_data);
2993 strbuf_reset(&sb);
2994 if (ret)
2995 break;
2996 } else if (!pos) {
2997 /*
2998 * We are at the start of the buffer, and the
2999 * start of the file; there is no previous
3000 * line, and we have everything for this one.
3001 * Process it, and we can end the loop.
3002 */
3003 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3004 ret = show_one_reflog_ent(&sb, fn, cb_data);
3005 strbuf_reset(&sb);
3006 break;
3007 }
3008
3009 if (bp == buf) {
3010 /*
3011 * We are at the start of the buffer, and there
3012 * is more file to read backwards. Which means
3013 * we are in the middle of a line. Note that we
3014 * may get here even if *bp was a newline; that
3015 * just means we are at the exact end of the
3016 * previous line, rather than some spot in the
3017 * middle.
3018 *
3019 * Save away what we have to be combined with
3020 * the data from the next read.
3021 */
3022 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3023 break;
3024 }
3025 }
3026
3027 }
3028 if (!ret && sb.len)
3029 die("BUG: reverse reflog parser had leftover data");
3030
3031 fclose(logfp);
3032 strbuf_release(&sb);
3033 return ret;
3034}
3035
3036int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3037{
3038 FILE *logfp;
3039 struct strbuf sb = STRBUF_INIT;
3040 int ret = 0;
3041
3042 logfp = fopen(git_path("logs/%s", refname), "r");
3043 if (!logfp)
3044 return -1;
3045
3046 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3047 ret = show_one_reflog_ent(&sb, fn, cb_data);
3048 fclose(logfp);
3049 strbuf_release(&sb);
3050 return ret;
3051}
3052/*
3053 * Call fn for each reflog in the namespace indicated by name. name
3054 * must be empty or end with '/'. Name will be used as a scratch
3055 * space, but its contents will be restored before return.
3056 */
3057static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
3058{
3059 DIR *d = opendir(git_path("logs/%s", name->buf));
3060 int retval = 0;
3061 struct dirent *de;
3062 int oldlen = name->len;
3063
3064 if (!d)
3065 return name->len ? errno : 0;
3066
3067 while ((de = readdir(d)) != NULL) {
3068 struct stat st;
3069
3070 if (de->d_name[0] == '.')
3071 continue;
3072 if (ends_with(de->d_name, ".lock"))
3073 continue;
3074 strbuf_addstr(name, de->d_name);
3075 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3076 ; /* silently ignore */
3077 } else {
3078 if (S_ISDIR(st.st_mode)) {
3079 strbuf_addch(name, '/');
3080 retval = do_for_each_reflog(name, fn, cb_data);
3081 } else {
3082 struct object_id oid;
3083
3084 if (read_ref_full(name->buf, 0, oid.hash, NULL))
3085 retval = error("bad ref for %s", name->buf);
3086 else
3087 retval = fn(name->buf, &oid, 0, cb_data);
3088 }
3089 if (retval)
3090 break;
3091 }
3092 strbuf_setlen(name, oldlen);
3093 }
3094 closedir(d);
3095 return retval;
3096}
3097
3098int for_each_reflog(each_ref_fn fn, void *cb_data)
3099{
3100 int retval;
3101 struct strbuf name;
3102 strbuf_init(&name, PATH_MAX);
3103 retval = do_for_each_reflog(&name, fn, cb_data);
3104 strbuf_release(&name);
3105 return retval;
3106}
3107
3108static int ref_update_reject_duplicates(struct string_list *refnames,
3109 struct strbuf *err)
3110{
3111 int i, n = refnames->nr;
3112
3113 assert(err);
3114
3115 for (i = 1; i < n; i++)
3116 if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {
3117 strbuf_addf(err,
3118 "Multiple updates for ref '%s' not allowed.",
3119 refnames->items[i].string);
3120 return 1;
3121 }
3122 return 0;
3123}
3124
3125int ref_transaction_commit(struct ref_transaction *transaction,
3126 struct strbuf *err)
3127{
3128 int ret = 0, i;
3129 int n = transaction->nr;
3130 struct ref_update **updates = transaction->updates;
3131 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;
3132 struct string_list_item *ref_to_delete;
3133 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
3134
3135 assert(err);
3136
3137 if (transaction->state != REF_TRANSACTION_OPEN)
3138 die("BUG: commit called for transaction that is not open");
3139
3140 if (!n) {
3141 transaction->state = REF_TRANSACTION_CLOSED;
3142 return 0;
3143 }
3144
3145 /* Fail if a refname appears more than once in the transaction: */
3146 for (i = 0; i < n; i++)
3147 string_list_append(&affected_refnames, updates[i]->refname);
3148 string_list_sort(&affected_refnames);
3149 if (ref_update_reject_duplicates(&affected_refnames, err)) {
3150 ret = TRANSACTION_GENERIC_ERROR;
3151 goto cleanup;
3152 }
3153
3154 /*
3155 * Acquire all locks, verify old values if provided, check
3156 * that new values are valid, and write new values to the
3157 * lockfiles, ready to be activated. Only keep one lockfile
3158 * open at a time to avoid running out of file descriptors.
3159 */
3160 for (i = 0; i < n; i++) {
3161 struct ref_update *update = updates[i];
3162
3163 if ((update->flags & REF_HAVE_NEW) &&
3164 is_null_sha1(update->new_sha1))
3165 update->flags |= REF_DELETING;
3166 update->lock = lock_ref_sha1_basic(
3167 update->refname,
3168 ((update->flags & REF_HAVE_OLD) ?
3169 update->old_sha1 : NULL),
3170 &affected_refnames, NULL,
3171 update->flags,
3172 &update->type,
3173 err);
3174 if (!update->lock) {
3175 char *reason;
3176
3177 ret = (errno == ENOTDIR)
3178 ? TRANSACTION_NAME_CONFLICT
3179 : TRANSACTION_GENERIC_ERROR;
3180 reason = strbuf_detach(err, NULL);
3181 strbuf_addf(err, "cannot lock ref '%s': %s",
3182 update->refname, reason);
3183 free(reason);
3184 goto cleanup;
3185 }
3186 if ((update->flags & REF_HAVE_NEW) &&
3187 !(update->flags & REF_DELETING)) {
3188 int overwriting_symref = ((update->type & REF_ISSYMREF) &&
3189 (update->flags & REF_NODEREF));
3190
3191 if (!overwriting_symref &&
3192 !hashcmp(update->lock->old_oid.hash, update->new_sha1)) {
3193 /*
3194 * The reference already has the desired
3195 * value, so we don't need to write it.
3196 */
3197 } else if (write_ref_to_lockfile(update->lock,
3198 update->new_sha1,
3199 err)) {
3200 char *write_err = strbuf_detach(err, NULL);
3201
3202 /*
3203 * The lock was freed upon failure of
3204 * write_ref_to_lockfile():
3205 */
3206 update->lock = NULL;
3207 strbuf_addf(err,
3208 "cannot update the ref '%s': %s",
3209 update->refname, write_err);
3210 free(write_err);
3211 ret = TRANSACTION_GENERIC_ERROR;
3212 goto cleanup;
3213 } else {
3214 update->flags |= REF_NEEDS_COMMIT;
3215 }
3216 }
3217 if (!(update->flags & REF_NEEDS_COMMIT)) {
3218 /*
3219 * We didn't have to write anything to the lockfile.
3220 * Close it to free up the file descriptor:
3221 */
3222 if (close_ref(update->lock)) {
3223 strbuf_addf(err, "Couldn't close %s.lock",
3224 update->refname);
3225 goto cleanup;
3226 }
3227 }
3228 }
3229
3230 /* Perform updates first so live commits remain referenced */
3231 for (i = 0; i < n; i++) {
3232 struct ref_update *update = updates[i];
3233
3234 if (update->flags & REF_NEEDS_COMMIT) {
3235 if (commit_ref_update(update->lock,
3236 update->new_sha1, update->msg,
3237 update->flags, err)) {
3238 /* freed by commit_ref_update(): */
3239 update->lock = NULL;
3240 ret = TRANSACTION_GENERIC_ERROR;
3241 goto cleanup;
3242 } else {
3243 /* freed by commit_ref_update(): */
3244 update->lock = NULL;
3245 }
3246 }
3247 }
3248
3249 /* Perform deletes now that updates are safely completed */
3250 for (i = 0; i < n; i++) {
3251 struct ref_update *update = updates[i];
3252
3253 if (update->flags & REF_DELETING) {
3254 if (delete_ref_loose(update->lock, update->type, err)) {
3255 ret = TRANSACTION_GENERIC_ERROR;
3256 goto cleanup;
3257 }
3258
3259 if (!(update->flags & REF_ISPRUNING))
3260 string_list_append(&refs_to_delete,
3261 update->lock->ref_name);
3262 }
3263 }
3264
3265 if (repack_without_refs(&refs_to_delete, err)) {
3266 ret = TRANSACTION_GENERIC_ERROR;
3267 goto cleanup;
3268 }
3269 for_each_string_list_item(ref_to_delete, &refs_to_delete)
3270 unlink_or_warn(git_path("logs/%s", ref_to_delete->string));
3271 clear_loose_ref_cache(&ref_cache);
3272
3273cleanup:
3274 transaction->state = REF_TRANSACTION_CLOSED;
3275
3276 for (i = 0; i < n; i++)
3277 if (updates[i]->lock)
3278 unlock_ref(updates[i]->lock);
3279 string_list_clear(&refs_to_delete, 0);
3280 string_list_clear(&affected_refnames, 0);
3281 return ret;
3282}
3283
3284static int ref_present(const char *refname,
3285 const struct object_id *oid, int flags, void *cb_data)
3286{
3287 struct string_list *affected_refnames = cb_data;
3288
3289 return string_list_has_string(affected_refnames, refname);
3290}
3291
3292int initial_ref_transaction_commit(struct ref_transaction *transaction,
3293 struct strbuf *err)
3294{
3295 int ret = 0, i;
3296 int n = transaction->nr;
3297 struct ref_update **updates = transaction->updates;
3298 struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
3299
3300 assert(err);
3301
3302 if (transaction->state != REF_TRANSACTION_OPEN)
3303 die("BUG: commit called for transaction that is not open");
3304
3305 /* Fail if a refname appears more than once in the transaction: */
3306 for (i = 0; i < n; i++)
3307 string_list_append(&affected_refnames, updates[i]->refname);
3308 string_list_sort(&affected_refnames);
3309 if (ref_update_reject_duplicates(&affected_refnames, err)) {
3310 ret = TRANSACTION_GENERIC_ERROR;
3311 goto cleanup;
3312 }
3313
3314 /*
3315 * It's really undefined to call this function in an active
3316 * repository or when there are existing references: we are
3317 * only locking and changing packed-refs, so (1) any
3318 * simultaneous processes might try to change a reference at
3319 * the same time we do, and (2) any existing loose versions of
3320 * the references that we are setting would have precedence
3321 * over our values. But some remote helpers create the remote
3322 * "HEAD" and "master" branches before calling this function,
3323 * so here we really only check that none of the references
3324 * that we are creating already exists.
3325 */
3326 if (for_each_rawref(ref_present, &affected_refnames))
3327 die("BUG: initial ref transaction called with existing refs");
3328
3329 for (i = 0; i < n; i++) {
3330 struct ref_update *update = updates[i];
3331
3332 if ((update->flags & REF_HAVE_OLD) &&
3333 !is_null_sha1(update->old_sha1))
3334 die("BUG: initial ref transaction with old_sha1 set");
3335 if (verify_refname_available(update->refname,
3336 &affected_refnames, NULL,
3337 err)) {
3338 ret = TRANSACTION_NAME_CONFLICT;
3339 goto cleanup;
3340 }
3341 }
3342
3343 if (lock_packed_refs(0)) {
3344 strbuf_addf(err, "unable to lock packed-refs file: %s",
3345 strerror(errno));
3346 ret = TRANSACTION_GENERIC_ERROR;
3347 goto cleanup;
3348 }
3349
3350 for (i = 0; i < n; i++) {
3351 struct ref_update *update = updates[i];
3352
3353 if ((update->flags & REF_HAVE_NEW) &&
3354 !is_null_sha1(update->new_sha1))
3355 add_packed_ref(update->refname, update->new_sha1);
3356 }
3357
3358 if (commit_packed_refs()) {
3359 strbuf_addf(err, "unable to commit packed-refs file: %s",
3360 strerror(errno));
3361 ret = TRANSACTION_GENERIC_ERROR;
3362 goto cleanup;
3363 }
3364
3365cleanup:
3366 transaction->state = REF_TRANSACTION_CLOSED;
3367 string_list_clear(&affected_refnames, 0);
3368 return ret;
3369}
3370
3371struct expire_reflog_cb {
3372 unsigned int flags;
3373 reflog_expiry_should_prune_fn *should_prune_fn;
3374 void *policy_cb;
3375 FILE *newlog;
3376 unsigned char last_kept_sha1[20];
3377};
3378
3379static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
3380 const char *email, unsigned long timestamp, int tz,
3381 const char *message, void *cb_data)
3382{
3383 struct expire_reflog_cb *cb = cb_data;
3384 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
3385
3386 if (cb->flags & EXPIRE_REFLOGS_REWRITE)
3387 osha1 = cb->last_kept_sha1;
3388
3389 if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,
3390 message, policy_cb)) {
3391 if (!cb->newlog)
3392 printf("would prune %s", message);
3393 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
3394 printf("prune %s", message);
3395 } else {
3396 if (cb->newlog) {
3397 fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",
3398 sha1_to_hex(osha1), sha1_to_hex(nsha1),
3399 email, timestamp, tz, message);
3400 hashcpy(cb->last_kept_sha1, nsha1);
3401 }
3402 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
3403 printf("keep %s", message);
3404 }
3405 return 0;
3406}
3407
3408int reflog_expire(const char *refname, const unsigned char *sha1,
3409 unsigned int flags,
3410 reflog_expiry_prepare_fn prepare_fn,
3411 reflog_expiry_should_prune_fn should_prune_fn,
3412 reflog_expiry_cleanup_fn cleanup_fn,
3413 void *policy_cb_data)
3414{
3415 static struct lock_file reflog_lock;
3416 struct expire_reflog_cb cb;
3417 struct ref_lock *lock;
3418 char *log_file;
3419 int status = 0;
3420 int type;
3421 struct strbuf err = STRBUF_INIT;
3422
3423 memset(&cb, 0, sizeof(cb));
3424 cb.flags = flags;
3425 cb.policy_cb = policy_cb_data;
3426 cb.should_prune_fn = should_prune_fn;
3427
3428 /*
3429 * The reflog file is locked by holding the lock on the
3430 * reference itself, plus we might need to update the
3431 * reference if --updateref was specified:
3432 */
3433 lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, 0, &type, &err);
3434 if (!lock) {
3435 error("cannot lock ref '%s': %s", refname, err.buf);
3436 strbuf_release(&err);
3437 return -1;
3438 }
3439 if (!reflog_exists(refname)) {
3440 unlock_ref(lock);
3441 return 0;
3442 }
3443
3444 log_file = git_pathdup("logs/%s", refname);
3445 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
3446 /*
3447 * Even though holding $GIT_DIR/logs/$reflog.lock has
3448 * no locking implications, we use the lock_file
3449 * machinery here anyway because it does a lot of the
3450 * work we need, including cleaning up if the program
3451 * exits unexpectedly.
3452 */
3453 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
3454 struct strbuf err = STRBUF_INIT;
3455 unable_to_lock_message(log_file, errno, &err);
3456 error("%s", err.buf);
3457 strbuf_release(&err);
3458 goto failure;
3459 }
3460 cb.newlog = fdopen_lock_file(&reflog_lock, "w");
3461 if (!cb.newlog) {
3462 error("cannot fdopen %s (%s)",
3463 get_lock_file_path(&reflog_lock), strerror(errno));
3464 goto failure;
3465 }
3466 }
3467
3468 (*prepare_fn)(refname, sha1, cb.policy_cb);
3469 for_each_reflog_ent(refname, expire_reflog_ent, &cb);
3470 (*cleanup_fn)(cb.policy_cb);
3471
3472 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
3473 /*
3474 * It doesn't make sense to adjust a reference pointed
3475 * to by a symbolic ref based on expiring entries in
3476 * the symbolic reference's reflog. Nor can we update
3477 * a reference if there are no remaining reflog
3478 * entries.
3479 */
3480 int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&
3481 !(type & REF_ISSYMREF) &&
3482 !is_null_sha1(cb.last_kept_sha1);
3483
3484 if (close_lock_file(&reflog_lock)) {
3485 status |= error("couldn't write %s: %s", log_file,
3486 strerror(errno));
3487 } else if (update &&
3488 (write_in_full(get_lock_file_fd(lock->lk),
3489 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
3490 write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||
3491 close_ref(lock) < 0)) {
3492 status |= error("couldn't write %s",
3493 get_lock_file_path(lock->lk));
3494 rollback_lock_file(&reflog_lock);
3495 } else if (commit_lock_file(&reflog_lock)) {
e0048d3e 3496 status |= error("unable to write reflog '%s' (%s)",
7bd9bcf3
MH
3497 log_file, strerror(errno));
3498 } else if (update && commit_ref(lock)) {
3499 status |= error("couldn't set %s", lock->ref_name);
3500 }
3501 }
3502 free(log_file);
3503 unlock_ref(lock);
3504 return status;
3505
3506 failure:
3507 rollback_lock_file(&reflog_lock);
3508 free(log_file);
3509 unlock_ref(lock);
3510 return -1;
3511}