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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 | ||
8 | struct ref_lock { | |
9 | char *ref_name; | |
10 | struct lock_file *lk; | |
11 | struct object_id old_oid; | |
12 | }; | |
13 | ||
14 | struct ref_entry; | |
15 | ||
16 | /* | |
17 | * Information used (along with the information in ref_entry) to | |
18 | * describe a single cached reference. This data structure only | |
19 | * occurs embedded in a union in struct ref_entry, and only when | |
20 | * (ref_entry->flag & REF_DIR) is zero. | |
21 | */ | |
22 | struct ref_value { | |
23 | /* | |
24 | * The name of the object to which this reference resolves | |
25 | * (which may be a tag object). If REF_ISBROKEN, this is | |
26 | * null. If REF_ISSYMREF, then this is the name of the object | |
27 | * referred to by the last reference in the symlink chain. | |
28 | */ | |
29 | struct object_id oid; | |
30 | ||
31 | /* | |
32 | * If REF_KNOWS_PEELED, then this field holds the peeled value | |
33 | * of this reference, or null if the reference is known not to | |
34 | * be peelable. See the documentation for peel_ref() for an | |
35 | * exact definition of "peelable". | |
36 | */ | |
37 | struct object_id peeled; | |
38 | }; | |
39 | ||
40 | struct ref_cache; | |
41 | ||
42 | /* | |
43 | * Information used (along with the information in ref_entry) to | |
44 | * describe a level in the hierarchy of references. This data | |
45 | * structure only occurs embedded in a union in struct ref_entry, and | |
46 | * only when (ref_entry.flag & REF_DIR) is set. In that case, | |
47 | * (ref_entry.flag & REF_INCOMPLETE) determines whether the references | |
48 | * in the directory have already been read: | |
49 | * | |
50 | * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose | |
51 | * or packed references, already read. | |
52 | * | |
53 | * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose | |
54 | * references that hasn't been read yet (nor has any of its | |
55 | * subdirectories). | |
56 | * | |
57 | * Entries within a directory are stored within a growable array of | |
58 | * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < | |
59 | * sorted are sorted by their component name in strcmp() order and the | |
60 | * remaining entries are unsorted. | |
61 | * | |
62 | * Loose references are read lazily, one directory at a time. When a | |
63 | * directory of loose references is read, then all of the references | |
64 | * in that directory are stored, and REF_INCOMPLETE stubs are created | |
65 | * for any subdirectories, but the subdirectories themselves are not | |
66 | * read. The reading is triggered by get_ref_dir(). | |
67 | */ | |
68 | struct ref_dir { | |
69 | int nr, alloc; | |
70 | ||
71 | /* | |
72 | * Entries with index 0 <= i < sorted are sorted by name. New | |
73 | * entries are appended to the list unsorted, and are sorted | |
74 | * only when required; thus we avoid the need to sort the list | |
75 | * after the addition of every reference. | |
76 | */ | |
77 | int sorted; | |
78 | ||
79 | /* A pointer to the ref_cache that contains this ref_dir. */ | |
80 | struct ref_cache *ref_cache; | |
81 | ||
82 | struct ref_entry **entries; | |
83 | }; | |
84 | ||
85 | /* | |
86 | * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, | |
87 | * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are | |
88 | * public values; see refs.h. | |
89 | */ | |
90 | ||
91 | /* | |
92 | * The field ref_entry->u.value.peeled of this value entry contains | |
93 | * the correct peeled value for the reference, which might be | |
94 | * null_sha1 if the reference is not a tag or if it is broken. | |
95 | */ | |
96 | #define REF_KNOWS_PEELED 0x10 | |
97 | ||
98 | /* ref_entry represents a directory of references */ | |
99 | #define REF_DIR 0x20 | |
100 | ||
101 | /* | |
102 | * Entry has not yet been read from disk (used only for REF_DIR | |
103 | * entries representing loose references) | |
104 | */ | |
105 | #define REF_INCOMPLETE 0x40 | |
106 | ||
107 | /* | |
108 | * A ref_entry represents either a reference or a "subdirectory" of | |
109 | * references. | |
110 | * | |
111 | * Each directory in the reference namespace is represented by a | |
112 | * ref_entry with (flags & REF_DIR) set and containing a subdir member | |
113 | * that holds the entries in that directory that have been read so | |
114 | * far. If (flags & REF_INCOMPLETE) is set, then the directory and | |
115 | * its subdirectories haven't been read yet. REF_INCOMPLETE is only | |
116 | * used for loose reference directories. | |
117 | * | |
118 | * References are represented by a ref_entry with (flags & REF_DIR) | |
119 | * unset and a value member that describes the reference's value. The | |
120 | * flag member is at the ref_entry level, but it is also needed to | |
121 | * interpret the contents of the value field (in other words, a | |
122 | * ref_value object is not very much use without the enclosing | |
123 | * ref_entry). | |
124 | * | |
125 | * Reference names cannot end with slash and directories' names are | |
126 | * always stored with a trailing slash (except for the top-level | |
127 | * directory, which is always denoted by ""). This has two nice | |
128 | * consequences: (1) when the entries in each subdir are sorted | |
129 | * lexicographically by name (as they usually are), the references in | |
130 | * a whole tree can be generated in lexicographic order by traversing | |
131 | * the tree in left-to-right, depth-first order; (2) the names of | |
132 | * references and subdirectories cannot conflict, and therefore the | |
133 | * presence of an empty subdirectory does not block the creation of a | |
134 | * similarly-named reference. (The fact that reference names with the | |
135 | * same leading components can conflict *with each other* is a | |
136 | * separate issue that is regulated by verify_refname_available().) | |
137 | * | |
138 | * Please note that the name field contains the fully-qualified | |
139 | * reference (or subdirectory) name. Space could be saved by only | |
140 | * storing the relative names. But that would require the full names | |
141 | * to be generated on the fly when iterating in do_for_each_ref(), and | |
142 | * would break callback functions, who have always been able to assume | |
143 | * that the name strings that they are passed will not be freed during | |
144 | * the iteration. | |
145 | */ | |
146 | struct ref_entry { | |
147 | unsigned char flag; /* ISSYMREF? ISPACKED? */ | |
148 | union { | |
149 | struct ref_value value; /* if not (flags&REF_DIR) */ | |
150 | struct ref_dir subdir; /* if (flags&REF_DIR) */ | |
151 | } u; | |
152 | /* | |
153 | * The full name of the reference (e.g., "refs/heads/master") | |
154 | * or the full name of the directory with a trailing slash | |
155 | * (e.g., "refs/heads/"): | |
156 | */ | |
157 | char name[FLEX_ARRAY]; | |
158 | }; | |
159 | ||
160 | static void read_loose_refs(const char *dirname, struct ref_dir *dir); | |
161 | static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len); | |
162 | static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, | |
163 | const char *dirname, size_t len, | |
164 | int incomplete); | |
165 | static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry); | |
166 | ||
167 | static struct ref_dir *get_ref_dir(struct ref_entry *entry) | |
168 | { | |
169 | struct ref_dir *dir; | |
170 | assert(entry->flag & REF_DIR); | |
171 | dir = &entry->u.subdir; | |
172 | if (entry->flag & REF_INCOMPLETE) { | |
173 | read_loose_refs(entry->name, dir); | |
174 | ||
175 | /* | |
176 | * Manually add refs/bisect, which, being | |
177 | * per-worktree, might not appear in the directory | |
178 | * listing for refs/ in the main repo. | |
179 | */ | |
180 | if (!strcmp(entry->name, "refs/")) { | |
181 | int pos = search_ref_dir(dir, "refs/bisect/", 12); | |
182 | if (pos < 0) { | |
183 | struct ref_entry *child_entry; | |
184 | child_entry = create_dir_entry(dir->ref_cache, | |
185 | "refs/bisect/", | |
186 | 12, 1); | |
187 | add_entry_to_dir(dir, child_entry); | |
188 | read_loose_refs("refs/bisect", | |
189 | &child_entry->u.subdir); | |
190 | } | |
191 | } | |
192 | entry->flag &= ~REF_INCOMPLETE; | |
193 | } | |
194 | return dir; | |
195 | } | |
196 | ||
197 | static struct ref_entry *create_ref_entry(const char *refname, | |
198 | const unsigned char *sha1, int flag, | |
199 | int check_name) | |
200 | { | |
201 | struct ref_entry *ref; | |
202 | ||
203 | if (check_name && | |
204 | check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) | |
205 | die("Reference has invalid format: '%s'", refname); | |
206 | FLEX_ALLOC_STR(ref, name, refname); | |
207 | hashcpy(ref->u.value.oid.hash, sha1); | |
208 | oidclr(&ref->u.value.peeled); | |
209 | ref->flag = flag; | |
210 | return ref; | |
211 | } | |
212 | ||
213 | static void clear_ref_dir(struct ref_dir *dir); | |
214 | ||
215 | static void free_ref_entry(struct ref_entry *entry) | |
216 | { | |
217 | if (entry->flag & REF_DIR) { | |
218 | /* | |
219 | * Do not use get_ref_dir() here, as that might | |
220 | * trigger the reading of loose refs. | |
221 | */ | |
222 | clear_ref_dir(&entry->u.subdir); | |
223 | } | |
224 | free(entry); | |
225 | } | |
226 | ||
227 | /* | |
228 | * Add a ref_entry to the end of dir (unsorted). Entry is always | |
229 | * stored directly in dir; no recursion into subdirectories is | |
230 | * done. | |
231 | */ | |
232 | static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry) | |
233 | { | |
234 | ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc); | |
235 | dir->entries[dir->nr++] = entry; | |
236 | /* optimize for the case that entries are added in order */ | |
237 | if (dir->nr == 1 || | |
238 | (dir->nr == dir->sorted + 1 && | |
239 | strcmp(dir->entries[dir->nr - 2]->name, | |
240 | dir->entries[dir->nr - 1]->name) < 0)) | |
241 | dir->sorted = dir->nr; | |
242 | } | |
243 | ||
244 | /* | |
245 | * Clear and free all entries in dir, recursively. | |
246 | */ | |
247 | static void clear_ref_dir(struct ref_dir *dir) | |
248 | { | |
249 | int i; | |
250 | for (i = 0; i < dir->nr; i++) | |
251 | free_ref_entry(dir->entries[i]); | |
252 | free(dir->entries); | |
253 | dir->sorted = dir->nr = dir->alloc = 0; | |
254 | dir->entries = NULL; | |
255 | } | |
256 | ||
257 | /* | |
258 | * Create a struct ref_entry object for the specified dirname. | |
259 | * dirname is the name of the directory with a trailing slash (e.g., | |
260 | * "refs/heads/") or "" for the top-level directory. | |
261 | */ | |
262 | static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, | |
263 | const char *dirname, size_t len, | |
264 | int incomplete) | |
265 | { | |
266 | struct ref_entry *direntry; | |
267 | FLEX_ALLOC_MEM(direntry, name, dirname, len); | |
268 | direntry->u.subdir.ref_cache = ref_cache; | |
269 | direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0); | |
270 | return direntry; | |
271 | } | |
272 | ||
273 | static int ref_entry_cmp(const void *a, const void *b) | |
274 | { | |
275 | struct ref_entry *one = *(struct ref_entry **)a; | |
276 | struct ref_entry *two = *(struct ref_entry **)b; | |
277 | return strcmp(one->name, two->name); | |
278 | } | |
279 | ||
280 | static void sort_ref_dir(struct ref_dir *dir); | |
281 | ||
282 | struct string_slice { | |
283 | size_t len; | |
284 | const char *str; | |
285 | }; | |
286 | ||
287 | static int ref_entry_cmp_sslice(const void *key_, const void *ent_) | |
288 | { | |
289 | const struct string_slice *key = key_; | |
290 | const struct ref_entry *ent = *(const struct ref_entry * const *)ent_; | |
291 | int cmp = strncmp(key->str, ent->name, key->len); | |
292 | if (cmp) | |
293 | return cmp; | |
294 | return '\0' - (unsigned char)ent->name[key->len]; | |
295 | } | |
296 | ||
297 | /* | |
298 | * Return the index of the entry with the given refname from the | |
299 | * ref_dir (non-recursively), sorting dir if necessary. Return -1 if | |
300 | * no such entry is found. dir must already be complete. | |
301 | */ | |
302 | static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len) | |
303 | { | |
304 | struct ref_entry **r; | |
305 | struct string_slice key; | |
306 | ||
307 | if (refname == NULL || !dir->nr) | |
308 | return -1; | |
309 | ||
310 | sort_ref_dir(dir); | |
311 | key.len = len; | |
312 | key.str = refname; | |
313 | r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries), | |
314 | ref_entry_cmp_sslice); | |
315 | ||
316 | if (r == NULL) | |
317 | return -1; | |
318 | ||
319 | return r - dir->entries; | |
320 | } | |
321 | ||
322 | /* | |
323 | * Search for a directory entry directly within dir (without | |
324 | * recursing). Sort dir if necessary. subdirname must be a directory | |
325 | * name (i.e., end in '/'). If mkdir is set, then create the | |
326 | * directory if it is missing; otherwise, return NULL if the desired | |
327 | * directory cannot be found. dir must already be complete. | |
328 | */ | |
329 | static struct ref_dir *search_for_subdir(struct ref_dir *dir, | |
330 | const char *subdirname, size_t len, | |
331 | int mkdir) | |
332 | { | |
333 | int entry_index = search_ref_dir(dir, subdirname, len); | |
334 | struct ref_entry *entry; | |
335 | if (entry_index == -1) { | |
336 | if (!mkdir) | |
337 | return NULL; | |
338 | /* | |
339 | * Since dir is complete, the absence of a subdir | |
340 | * means that the subdir really doesn't exist; | |
341 | * therefore, create an empty record for it but mark | |
342 | * the record complete. | |
343 | */ | |
344 | entry = create_dir_entry(dir->ref_cache, subdirname, len, 0); | |
345 | add_entry_to_dir(dir, entry); | |
346 | } else { | |
347 | entry = dir->entries[entry_index]; | |
348 | } | |
349 | return get_ref_dir(entry); | |
350 | } | |
351 | ||
352 | /* | |
353 | * If refname is a reference name, find the ref_dir within the dir | |
354 | * tree that should hold refname. If refname is a directory name | |
355 | * (i.e., ends in '/'), then return that ref_dir itself. dir must | |
356 | * represent the top-level directory and must already be complete. | |
357 | * Sort ref_dirs and recurse into subdirectories as necessary. If | |
358 | * mkdir is set, then create any missing directories; otherwise, | |
359 | * return NULL if the desired directory cannot be found. | |
360 | */ | |
361 | static struct ref_dir *find_containing_dir(struct ref_dir *dir, | |
362 | const char *refname, int mkdir) | |
363 | { | |
364 | const char *slash; | |
365 | for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { | |
366 | size_t dirnamelen = slash - refname + 1; | |
367 | struct ref_dir *subdir; | |
368 | subdir = search_for_subdir(dir, refname, dirnamelen, mkdir); | |
369 | if (!subdir) { | |
370 | dir = NULL; | |
371 | break; | |
372 | } | |
373 | dir = subdir; | |
374 | } | |
375 | ||
376 | return dir; | |
377 | } | |
378 | ||
379 | /* | |
380 | * Find the value entry with the given name in dir, sorting ref_dirs | |
381 | * and recursing into subdirectories as necessary. If the name is not | |
382 | * found or it corresponds to a directory entry, return NULL. | |
383 | */ | |
384 | static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname) | |
385 | { | |
386 | int entry_index; | |
387 | struct ref_entry *entry; | |
388 | dir = find_containing_dir(dir, refname, 0); | |
389 | if (!dir) | |
390 | return NULL; | |
391 | entry_index = search_ref_dir(dir, refname, strlen(refname)); | |
392 | if (entry_index == -1) | |
393 | return NULL; | |
394 | entry = dir->entries[entry_index]; | |
395 | return (entry->flag & REF_DIR) ? NULL : entry; | |
396 | } | |
397 | ||
398 | /* | |
399 | * Remove the entry with the given name from dir, recursing into | |
400 | * subdirectories as necessary. If refname is the name of a directory | |
401 | * (i.e., ends with '/'), then remove the directory and its contents. | |
402 | * If the removal was successful, return the number of entries | |
403 | * remaining in the directory entry that contained the deleted entry. | |
404 | * If the name was not found, return -1. Please note that this | |
405 | * function only deletes the entry from the cache; it does not delete | |
406 | * it from the filesystem or ensure that other cache entries (which | |
407 | * might be symbolic references to the removed entry) are updated. | |
408 | * Nor does it remove any containing dir entries that might be made | |
409 | * empty by the removal. dir must represent the top-level directory | |
410 | * and must already be complete. | |
411 | */ | |
412 | static int remove_entry(struct ref_dir *dir, const char *refname) | |
413 | { | |
414 | int refname_len = strlen(refname); | |
415 | int entry_index; | |
416 | struct ref_entry *entry; | |
417 | int is_dir = refname[refname_len - 1] == '/'; | |
418 | if (is_dir) { | |
419 | /* | |
420 | * refname represents a reference directory. Remove | |
421 | * the trailing slash; otherwise we will get the | |
422 | * directory *representing* refname rather than the | |
423 | * one *containing* it. | |
424 | */ | |
425 | char *dirname = xmemdupz(refname, refname_len - 1); | |
426 | dir = find_containing_dir(dir, dirname, 0); | |
427 | free(dirname); | |
428 | } else { | |
429 | dir = find_containing_dir(dir, refname, 0); | |
430 | } | |
431 | if (!dir) | |
432 | return -1; | |
433 | entry_index = search_ref_dir(dir, refname, refname_len); | |
434 | if (entry_index == -1) | |
435 | return -1; | |
436 | entry = dir->entries[entry_index]; | |
437 | ||
438 | memmove(&dir->entries[entry_index], | |
439 | &dir->entries[entry_index + 1], | |
440 | (dir->nr - entry_index - 1) * sizeof(*dir->entries) | |
441 | ); | |
442 | dir->nr--; | |
443 | if (dir->sorted > entry_index) | |
444 | dir->sorted--; | |
445 | free_ref_entry(entry); | |
446 | return dir->nr; | |
447 | } | |
448 | ||
449 | /* | |
450 | * Add a ref_entry to the ref_dir (unsorted), recursing into | |
451 | * subdirectories as necessary. dir must represent the top-level | |
452 | * directory. Return 0 on success. | |
453 | */ | |
454 | static int add_ref(struct ref_dir *dir, struct ref_entry *ref) | |
455 | { | |
456 | dir = find_containing_dir(dir, ref->name, 1); | |
457 | if (!dir) | |
458 | return -1; | |
459 | add_entry_to_dir(dir, ref); | |
460 | return 0; | |
461 | } | |
462 | ||
463 | /* | |
464 | * Emit a warning and return true iff ref1 and ref2 have the same name | |
465 | * and the same sha1. Die if they have the same name but different | |
466 | * sha1s. | |
467 | */ | |
468 | static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2) | |
469 | { | |
470 | if (strcmp(ref1->name, ref2->name)) | |
471 | return 0; | |
472 | ||
473 | /* Duplicate name; make sure that they don't conflict: */ | |
474 | ||
475 | if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) | |
476 | /* This is impossible by construction */ | |
477 | die("Reference directory conflict: %s", ref1->name); | |
478 | ||
479 | if (oidcmp(&ref1->u.value.oid, &ref2->u.value.oid)) | |
480 | die("Duplicated ref, and SHA1s don't match: %s", ref1->name); | |
481 | ||
482 | warning("Duplicated ref: %s", ref1->name); | |
483 | return 1; | |
484 | } | |
485 | ||
486 | /* | |
487 | * Sort the entries in dir non-recursively (if they are not already | |
488 | * sorted) and remove any duplicate entries. | |
489 | */ | |
490 | static void sort_ref_dir(struct ref_dir *dir) | |
491 | { | |
492 | int i, j; | |
493 | struct ref_entry *last = NULL; | |
494 | ||
495 | /* | |
496 | * This check also prevents passing a zero-length array to qsort(), | |
497 | * which is a problem on some platforms. | |
498 | */ | |
499 | if (dir->sorted == dir->nr) | |
500 | return; | |
501 | ||
502 | qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp); | |
503 | ||
504 | /* Remove any duplicates: */ | |
505 | for (i = 0, j = 0; j < dir->nr; j++) { | |
506 | struct ref_entry *entry = dir->entries[j]; | |
507 | if (last && is_dup_ref(last, entry)) | |
508 | free_ref_entry(entry); | |
509 | else | |
510 | last = dir->entries[i++] = entry; | |
511 | } | |
512 | dir->sorted = dir->nr = i; | |
513 | } | |
514 | ||
515 | /* | |
516 | * Return true if refname, which has the specified oid and flags, can | |
517 | * be resolved to an object in the database. If the referred-to object | |
518 | * does not exist, emit a warning and return false. | |
519 | */ | |
520 | static int ref_resolves_to_object(const char *refname, | |
521 | const struct object_id *oid, | |
522 | unsigned int flags) | |
523 | { | |
524 | if (flags & REF_ISBROKEN) | |
525 | return 0; | |
526 | if (!has_sha1_file(oid->hash)) { | |
527 | error("%s does not point to a valid object!", refname); | |
528 | return 0; | |
529 | } | |
530 | return 1; | |
531 | } | |
532 | ||
533 | /* | |
534 | * Return true if the reference described by entry can be resolved to | |
535 | * an object in the database; otherwise, emit a warning and return | |
536 | * false. | |
537 | */ | |
538 | static int entry_resolves_to_object(struct ref_entry *entry) | |
539 | { | |
540 | return ref_resolves_to_object(entry->name, | |
541 | &entry->u.value.oid, entry->flag); | |
542 | } | |
543 | ||
544 | /* | |
545 | * current_ref is a performance hack: when iterating over references | |
546 | * using the for_each_ref*() functions, current_ref is set to the | |
547 | * current reference's entry before calling the callback function. If | |
548 | * the callback function calls peel_ref(), then peel_ref() first | |
549 | * checks whether the reference to be peeled is the current reference | |
550 | * (it usually is) and if so, returns that reference's peeled version | |
551 | * if it is available. This avoids a refname lookup in a common case. | |
552 | */ | |
553 | static struct ref_entry *current_ref; | |
554 | ||
555 | typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data); | |
556 | ||
557 | struct ref_entry_cb { | |
558 | const char *prefix; | |
559 | int trim; | |
560 | int flags; | |
561 | each_ref_fn *fn; | |
562 | void *cb_data; | |
563 | }; | |
564 | ||
565 | /* | |
566 | * Handle one reference in a do_for_each_ref*()-style iteration, | |
567 | * calling an each_ref_fn for each entry. | |
568 | */ | |
569 | static int do_one_ref(struct ref_entry *entry, void *cb_data) | |
570 | { | |
571 | struct ref_entry_cb *data = cb_data; | |
572 | struct ref_entry *old_current_ref; | |
573 | int retval; | |
574 | ||
575 | if (!starts_with(entry->name, data->prefix)) | |
576 | return 0; | |
577 | ||
578 | if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && | |
579 | !entry_resolves_to_object(entry)) | |
580 | return 0; | |
581 | ||
582 | /* Store the old value, in case this is a recursive call: */ | |
583 | old_current_ref = current_ref; | |
584 | current_ref = entry; | |
585 | retval = data->fn(entry->name + data->trim, &entry->u.value.oid, | |
586 | entry->flag, data->cb_data); | |
587 | current_ref = old_current_ref; | |
588 | return retval; | |
589 | } | |
590 | ||
591 | /* | |
592 | * Call fn for each reference in dir that has index in the range | |
593 | * offset <= index < dir->nr. Recurse into subdirectories that are in | |
594 | * that index range, sorting them before iterating. This function | |
595 | * does not sort dir itself; it should be sorted beforehand. fn is | |
596 | * called for all references, including broken ones. | |
597 | */ | |
598 | static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset, | |
599 | each_ref_entry_fn fn, void *cb_data) | |
600 | { | |
601 | int i; | |
602 | assert(dir->sorted == dir->nr); | |
603 | for (i = offset; i < dir->nr; i++) { | |
604 | struct ref_entry *entry = dir->entries[i]; | |
605 | int retval; | |
606 | if (entry->flag & REF_DIR) { | |
607 | struct ref_dir *subdir = get_ref_dir(entry); | |
608 | sort_ref_dir(subdir); | |
609 | retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data); | |
610 | } else { | |
611 | retval = fn(entry, cb_data); | |
612 | } | |
613 | if (retval) | |
614 | return retval; | |
615 | } | |
616 | return 0; | |
617 | } | |
618 | ||
619 | /* | |
620 | * Call fn for each reference in the union of dir1 and dir2, in order | |
621 | * by refname. Recurse into subdirectories. If a value entry appears | |
622 | * in both dir1 and dir2, then only process the version that is in | |
623 | * dir2. The input dirs must already be sorted, but subdirs will be | |
624 | * sorted as needed. fn is called for all references, including | |
625 | * broken ones. | |
626 | */ | |
627 | static int do_for_each_entry_in_dirs(struct ref_dir *dir1, | |
628 | struct ref_dir *dir2, | |
629 | each_ref_entry_fn fn, void *cb_data) | |
630 | { | |
631 | int retval; | |
632 | int i1 = 0, i2 = 0; | |
633 | ||
634 | assert(dir1->sorted == dir1->nr); | |
635 | assert(dir2->sorted == dir2->nr); | |
636 | while (1) { | |
637 | struct ref_entry *e1, *e2; | |
638 | int cmp; | |
639 | if (i1 == dir1->nr) { | |
640 | return do_for_each_entry_in_dir(dir2, i2, fn, cb_data); | |
641 | } | |
642 | if (i2 == dir2->nr) { | |
643 | return do_for_each_entry_in_dir(dir1, i1, fn, cb_data); | |
644 | } | |
645 | e1 = dir1->entries[i1]; | |
646 | e2 = dir2->entries[i2]; | |
647 | cmp = strcmp(e1->name, e2->name); | |
648 | if (cmp == 0) { | |
649 | if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { | |
650 | /* Both are directories; descend them in parallel. */ | |
651 | struct ref_dir *subdir1 = get_ref_dir(e1); | |
652 | struct ref_dir *subdir2 = get_ref_dir(e2); | |
653 | sort_ref_dir(subdir1); | |
654 | sort_ref_dir(subdir2); | |
655 | retval = do_for_each_entry_in_dirs( | |
656 | subdir1, subdir2, fn, cb_data); | |
657 | i1++; | |
658 | i2++; | |
659 | } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { | |
660 | /* Both are references; ignore the one from dir1. */ | |
661 | retval = fn(e2, cb_data); | |
662 | i1++; | |
663 | i2++; | |
664 | } else { | |
665 | die("conflict between reference and directory: %s", | |
666 | e1->name); | |
667 | } | |
668 | } else { | |
669 | struct ref_entry *e; | |
670 | if (cmp < 0) { | |
671 | e = e1; | |
672 | i1++; | |
673 | } else { | |
674 | e = e2; | |
675 | i2++; | |
676 | } | |
677 | if (e->flag & REF_DIR) { | |
678 | struct ref_dir *subdir = get_ref_dir(e); | |
679 | sort_ref_dir(subdir); | |
680 | retval = do_for_each_entry_in_dir( | |
681 | subdir, 0, fn, cb_data); | |
682 | } else { | |
683 | retval = fn(e, cb_data); | |
684 | } | |
685 | } | |
686 | if (retval) | |
687 | return retval; | |
688 | } | |
689 | } | |
690 | ||
691 | /* | |
692 | * Load all of the refs from the dir into our in-memory cache. The hard work | |
693 | * of loading loose refs is done by get_ref_dir(), so we just need to recurse | |
694 | * through all of the sub-directories. We do not even need to care about | |
695 | * sorting, as traversal order does not matter to us. | |
696 | */ | |
697 | static void prime_ref_dir(struct ref_dir *dir) | |
698 | { | |
699 | int i; | |
700 | for (i = 0; i < dir->nr; i++) { | |
701 | struct ref_entry *entry = dir->entries[i]; | |
702 | if (entry->flag & REF_DIR) | |
703 | prime_ref_dir(get_ref_dir(entry)); | |
704 | } | |
705 | } | |
706 | ||
707 | struct nonmatching_ref_data { | |
708 | const struct string_list *skip; | |
709 | const char *conflicting_refname; | |
710 | }; | |
711 | ||
712 | static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) | |
713 | { | |
714 | struct nonmatching_ref_data *data = vdata; | |
715 | ||
716 | if (data->skip && string_list_has_string(data->skip, entry->name)) | |
717 | return 0; | |
718 | ||
719 | data->conflicting_refname = entry->name; | |
720 | return 1; | |
721 | } | |
722 | ||
723 | /* | |
724 | * Return 0 if a reference named refname could be created without | |
725 | * conflicting with the name of an existing reference in dir. | |
726 | * See verify_refname_available for more information. | |
727 | */ | |
728 | static int verify_refname_available_dir(const char *refname, | |
729 | const struct string_list *extras, | |
730 | const struct string_list *skip, | |
731 | struct ref_dir *dir, | |
732 | struct strbuf *err) | |
733 | { | |
734 | const char *slash; | |
735 | const char *extra_refname; | |
736 | int pos; | |
737 | struct strbuf dirname = STRBUF_INIT; | |
738 | int ret = -1; | |
739 | ||
740 | /* | |
741 | * For the sake of comments in this function, suppose that | |
742 | * refname is "refs/foo/bar". | |
743 | */ | |
744 | ||
745 | assert(err); | |
746 | ||
747 | strbuf_grow(&dirname, strlen(refname) + 1); | |
748 | for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { | |
749 | /* Expand dirname to the new prefix, not including the trailing slash: */ | |
750 | strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); | |
751 | ||
752 | /* | |
753 | * We are still at a leading dir of the refname (e.g., | |
754 | * "refs/foo"; if there is a reference with that name, | |
755 | * it is a conflict, *unless* it is in skip. | |
756 | */ | |
757 | if (dir) { | |
758 | pos = search_ref_dir(dir, dirname.buf, dirname.len); | |
759 | if (pos >= 0 && | |
760 | (!skip || !string_list_has_string(skip, dirname.buf))) { | |
761 | /* | |
762 | * We found a reference whose name is | |
763 | * a proper prefix of refname; e.g., | |
764 | * "refs/foo", and is not in skip. | |
765 | */ | |
766 | strbuf_addf(err, "'%s' exists; cannot create '%s'", | |
767 | dirname.buf, refname); | |
768 | goto cleanup; | |
769 | } | |
770 | } | |
771 | ||
772 | if (extras && string_list_has_string(extras, dirname.buf) && | |
773 | (!skip || !string_list_has_string(skip, dirname.buf))) { | |
774 | strbuf_addf(err, "cannot process '%s' and '%s' at the same time", | |
775 | refname, dirname.buf); | |
776 | goto cleanup; | |
777 | } | |
778 | ||
779 | /* | |
780 | * Otherwise, we can try to continue our search with | |
781 | * the next component. So try to look up the | |
782 | * directory, e.g., "refs/foo/". If we come up empty, | |
783 | * we know there is nothing under this whole prefix, | |
784 | * but even in that case we still have to continue the | |
785 | * search for conflicts with extras. | |
786 | */ | |
787 | strbuf_addch(&dirname, '/'); | |
788 | if (dir) { | |
789 | pos = search_ref_dir(dir, dirname.buf, dirname.len); | |
790 | if (pos < 0) { | |
791 | /* | |
792 | * There was no directory "refs/foo/", | |
793 | * so there is nothing under this | |
794 | * whole prefix. So there is no need | |
795 | * to continue looking for conflicting | |
796 | * references. But we need to continue | |
797 | * looking for conflicting extras. | |
798 | */ | |
799 | dir = NULL; | |
800 | } else { | |
801 | dir = get_ref_dir(dir->entries[pos]); | |
802 | } | |
803 | } | |
804 | } | |
805 | ||
806 | /* | |
807 | * We are at the leaf of our refname (e.g., "refs/foo/bar"). | |
808 | * There is no point in searching for a reference with that | |
809 | * name, because a refname isn't considered to conflict with | |
810 | * itself. But we still need to check for references whose | |
811 | * names are in the "refs/foo/bar/" namespace, because they | |
812 | * *do* conflict. | |
813 | */ | |
814 | strbuf_addstr(&dirname, refname + dirname.len); | |
815 | strbuf_addch(&dirname, '/'); | |
816 | ||
817 | if (dir) { | |
818 | pos = search_ref_dir(dir, dirname.buf, dirname.len); | |
819 | ||
820 | if (pos >= 0) { | |
821 | /* | |
822 | * We found a directory named "$refname/" | |
823 | * (e.g., "refs/foo/bar/"). It is a problem | |
824 | * iff it contains any ref that is not in | |
825 | * "skip". | |
826 | */ | |
827 | struct nonmatching_ref_data data; | |
828 | ||
829 | data.skip = skip; | |
830 | data.conflicting_refname = NULL; | |
831 | dir = get_ref_dir(dir->entries[pos]); | |
832 | sort_ref_dir(dir); | |
833 | if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) { | |
834 | strbuf_addf(err, "'%s' exists; cannot create '%s'", | |
835 | data.conflicting_refname, refname); | |
836 | goto cleanup; | |
837 | } | |
838 | } | |
839 | } | |
840 | ||
841 | extra_refname = find_descendant_ref(dirname.buf, extras, skip); | |
842 | if (extra_refname) | |
843 | strbuf_addf(err, "cannot process '%s' and '%s' at the same time", | |
844 | refname, extra_refname); | |
845 | else | |
846 | ret = 0; | |
847 | ||
848 | cleanup: | |
849 | strbuf_release(&dirname); | |
850 | return ret; | |
851 | } | |
852 | ||
853 | struct packed_ref_cache { | |
854 | struct ref_entry *root; | |
855 | ||
856 | /* | |
857 | * Count of references to the data structure in this instance, | |
858 | * including the pointer from ref_cache::packed if any. The | |
859 | * data will not be freed as long as the reference count is | |
860 | * nonzero. | |
861 | */ | |
862 | unsigned int referrers; | |
863 | ||
864 | /* | |
865 | * Iff the packed-refs file associated with this instance is | |
866 | * currently locked for writing, this points at the associated | |
867 | * lock (which is owned by somebody else). The referrer count | |
868 | * is also incremented when the file is locked and decremented | |
869 | * when it is unlocked. | |
870 | */ | |
871 | struct lock_file *lock; | |
872 | ||
873 | /* The metadata from when this packed-refs cache was read */ | |
874 | struct stat_validity validity; | |
875 | }; | |
876 | ||
877 | /* | |
878 | * Future: need to be in "struct repository" | |
879 | * when doing a full libification. | |
880 | */ | |
881 | static struct ref_cache { | |
882 | struct ref_cache *next; | |
883 | struct ref_entry *loose; | |
884 | struct packed_ref_cache *packed; | |
885 | /* | |
886 | * The submodule name, or "" for the main repo. We allocate | |
887 | * length 1 rather than FLEX_ARRAY so that the main ref_cache | |
888 | * is initialized correctly. | |
889 | */ | |
890 | char name[1]; | |
891 | } ref_cache, *submodule_ref_caches; | |
892 | ||
893 | /* Lock used for the main packed-refs file: */ | |
894 | static struct lock_file packlock; | |
895 | ||
896 | /* | |
897 | * Increment the reference count of *packed_refs. | |
898 | */ | |
899 | static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) | |
900 | { | |
901 | packed_refs->referrers++; | |
902 | } | |
903 | ||
904 | /* | |
905 | * Decrease the reference count of *packed_refs. If it goes to zero, | |
906 | * free *packed_refs and return true; otherwise return false. | |
907 | */ | |
908 | static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) | |
909 | { | |
910 | if (!--packed_refs->referrers) { | |
911 | free_ref_entry(packed_refs->root); | |
912 | stat_validity_clear(&packed_refs->validity); | |
913 | free(packed_refs); | |
914 | return 1; | |
915 | } else { | |
916 | return 0; | |
917 | } | |
918 | } | |
919 | ||
920 | static void clear_packed_ref_cache(struct ref_cache *refs) | |
921 | { | |
922 | if (refs->packed) { | |
923 | struct packed_ref_cache *packed_refs = refs->packed; | |
924 | ||
925 | if (packed_refs->lock) | |
926 | die("internal error: packed-ref cache cleared while locked"); | |
927 | refs->packed = NULL; | |
928 | release_packed_ref_cache(packed_refs); | |
929 | } | |
930 | } | |
931 | ||
932 | static void clear_loose_ref_cache(struct ref_cache *refs) | |
933 | { | |
934 | if (refs->loose) { | |
935 | free_ref_entry(refs->loose); | |
936 | refs->loose = NULL; | |
937 | } | |
938 | } | |
939 | ||
940 | /* | |
941 | * Create a new submodule ref cache and add it to the internal | |
942 | * set of caches. | |
943 | */ | |
944 | static struct ref_cache *create_ref_cache(const char *submodule) | |
945 | { | |
946 | struct ref_cache *refs; | |
947 | if (!submodule) | |
948 | submodule = ""; | |
949 | FLEX_ALLOC_STR(refs, name, submodule); | |
950 | refs->next = submodule_ref_caches; | |
951 | submodule_ref_caches = refs; | |
952 | return refs; | |
953 | } | |
954 | ||
955 | static struct ref_cache *lookup_ref_cache(const char *submodule) | |
956 | { | |
957 | struct ref_cache *refs; | |
958 | ||
959 | if (!submodule || !*submodule) | |
960 | return &ref_cache; | |
961 | ||
962 | for (refs = submodule_ref_caches; refs; refs = refs->next) | |
963 | if (!strcmp(submodule, refs->name)) | |
964 | return refs; | |
965 | return NULL; | |
966 | } | |
967 | ||
968 | /* | |
969 | * Return a pointer to a ref_cache for the specified submodule. For | |
970 | * the main repository, use submodule==NULL; such a call cannot fail. | |
971 | * For a submodule, the submodule must exist and be a nonbare | |
972 | * repository, otherwise return NULL. | |
973 | * | |
974 | * The returned structure will be allocated and initialized but not | |
975 | * necessarily populated; it should not be freed. | |
976 | */ | |
977 | static struct ref_cache *get_ref_cache(const char *submodule) | |
978 | { | |
979 | struct ref_cache *refs = lookup_ref_cache(submodule); | |
980 | ||
981 | if (!refs) { | |
982 | struct strbuf submodule_sb = STRBUF_INIT; | |
983 | ||
984 | strbuf_addstr(&submodule_sb, submodule); | |
985 | if (is_nonbare_repository_dir(&submodule_sb)) | |
986 | refs = create_ref_cache(submodule); | |
987 | strbuf_release(&submodule_sb); | |
988 | } | |
989 | ||
990 | return refs; | |
991 | } | |
992 | ||
993 | /* The length of a peeled reference line in packed-refs, including EOL: */ | |
994 | #define PEELED_LINE_LENGTH 42 | |
995 | ||
996 | /* | |
997 | * The packed-refs header line that we write out. Perhaps other | |
998 | * traits will be added later. The trailing space is required. | |
999 | */ | |
1000 | static const char PACKED_REFS_HEADER[] = | |
1001 | "# pack-refs with: peeled fully-peeled \n"; | |
1002 | ||
1003 | /* | |
1004 | * Parse one line from a packed-refs file. Write the SHA1 to sha1. | |
1005 | * Return a pointer to the refname within the line (null-terminated), | |
1006 | * or NULL if there was a problem. | |
1007 | */ | |
1008 | static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1) | |
1009 | { | |
1010 | const char *ref; | |
1011 | ||
1012 | /* | |
1013 | * 42: the answer to everything. | |
1014 | * | |
1015 | * In this case, it happens to be the answer to | |
1016 | * 40 (length of sha1 hex representation) | |
1017 | * +1 (space in between hex and name) | |
1018 | * +1 (newline at the end of the line) | |
1019 | */ | |
1020 | if (line->len <= 42) | |
1021 | return NULL; | |
1022 | ||
1023 | if (get_sha1_hex(line->buf, sha1) < 0) | |
1024 | return NULL; | |
1025 | if (!isspace(line->buf[40])) | |
1026 | return NULL; | |
1027 | ||
1028 | ref = line->buf + 41; | |
1029 | if (isspace(*ref)) | |
1030 | return NULL; | |
1031 | ||
1032 | if (line->buf[line->len - 1] != '\n') | |
1033 | return NULL; | |
1034 | line->buf[--line->len] = 0; | |
1035 | ||
1036 | return ref; | |
1037 | } | |
1038 | ||
1039 | /* | |
1040 | * Read f, which is a packed-refs file, into dir. | |
1041 | * | |
1042 | * A comment line of the form "# pack-refs with: " may contain zero or | |
1043 | * more traits. We interpret the traits as follows: | |
1044 | * | |
1045 | * No traits: | |
1046 | * | |
1047 | * Probably no references are peeled. But if the file contains a | |
1048 | * peeled value for a reference, we will use it. | |
1049 | * | |
1050 | * peeled: | |
1051 | * | |
1052 | * References under "refs/tags/", if they *can* be peeled, *are* | |
1053 | * peeled in this file. References outside of "refs/tags/" are | |
1054 | * probably not peeled even if they could have been, but if we find | |
1055 | * a peeled value for such a reference we will use it. | |
1056 | * | |
1057 | * fully-peeled: | |
1058 | * | |
1059 | * All references in the file that can be peeled are peeled. | |
1060 | * Inversely (and this is more important), any references in the | |
1061 | * file for which no peeled value is recorded is not peelable. This | |
1062 | * trait should typically be written alongside "peeled" for | |
1063 | * compatibility with older clients, but we do not require it | |
1064 | * (i.e., "peeled" is a no-op if "fully-peeled" is set). | |
1065 | */ | |
1066 | static void read_packed_refs(FILE *f, struct ref_dir *dir) | |
1067 | { | |
1068 | struct ref_entry *last = NULL; | |
1069 | struct strbuf line = STRBUF_INIT; | |
1070 | enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; | |
1071 | ||
1072 | while (strbuf_getwholeline(&line, f, '\n') != EOF) { | |
1073 | unsigned char sha1[20]; | |
1074 | const char *refname; | |
1075 | const char *traits; | |
1076 | ||
1077 | if (skip_prefix(line.buf, "# pack-refs with:", &traits)) { | |
1078 | if (strstr(traits, " fully-peeled ")) | |
1079 | peeled = PEELED_FULLY; | |
1080 | else if (strstr(traits, " peeled ")) | |
1081 | peeled = PEELED_TAGS; | |
1082 | /* perhaps other traits later as well */ | |
1083 | continue; | |
1084 | } | |
1085 | ||
1086 | refname = parse_ref_line(&line, sha1); | |
1087 | if (refname) { | |
1088 | int flag = REF_ISPACKED; | |
1089 | ||
1090 | if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { | |
1091 | if (!refname_is_safe(refname)) | |
1092 | die("packed refname is dangerous: %s", refname); | |
1093 | hashclr(sha1); | |
1094 | flag |= REF_BAD_NAME | REF_ISBROKEN; | |
1095 | } | |
1096 | last = create_ref_entry(refname, sha1, flag, 0); | |
1097 | if (peeled == PEELED_FULLY || | |
1098 | (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/"))) | |
1099 | last->flag |= REF_KNOWS_PEELED; | |
1100 | add_ref(dir, last); | |
1101 | continue; | |
1102 | } | |
1103 | if (last && | |
1104 | line.buf[0] == '^' && | |
1105 | line.len == PEELED_LINE_LENGTH && | |
1106 | line.buf[PEELED_LINE_LENGTH - 1] == '\n' && | |
1107 | !get_sha1_hex(line.buf + 1, sha1)) { | |
1108 | hashcpy(last->u.value.peeled.hash, sha1); | |
1109 | /* | |
1110 | * Regardless of what the file header said, | |
1111 | * we definitely know the value of *this* | |
1112 | * reference: | |
1113 | */ | |
1114 | last->flag |= REF_KNOWS_PEELED; | |
1115 | } | |
1116 | } | |
1117 | ||
1118 | strbuf_release(&line); | |
1119 | } | |
1120 | ||
1121 | /* | |
1122 | * Get the packed_ref_cache for the specified ref_cache, creating it | |
1123 | * if necessary. | |
1124 | */ | |
1125 | static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs) | |
1126 | { | |
1127 | char *packed_refs_file; | |
1128 | ||
1129 | if (*refs->name) | |
1130 | packed_refs_file = git_pathdup_submodule(refs->name, "packed-refs"); | |
1131 | else | |
1132 | packed_refs_file = git_pathdup("packed-refs"); | |
1133 | ||
1134 | if (refs->packed && | |
1135 | !stat_validity_check(&refs->packed->validity, packed_refs_file)) | |
1136 | clear_packed_ref_cache(refs); | |
1137 | ||
1138 | if (!refs->packed) { | |
1139 | FILE *f; | |
1140 | ||
1141 | refs->packed = xcalloc(1, sizeof(*refs->packed)); | |
1142 | acquire_packed_ref_cache(refs->packed); | |
1143 | refs->packed->root = create_dir_entry(refs, "", 0, 0); | |
1144 | f = fopen(packed_refs_file, "r"); | |
1145 | if (f) { | |
1146 | stat_validity_update(&refs->packed->validity, fileno(f)); | |
1147 | read_packed_refs(f, get_ref_dir(refs->packed->root)); | |
1148 | fclose(f); | |
1149 | } | |
1150 | } | |
1151 | free(packed_refs_file); | |
1152 | return refs->packed; | |
1153 | } | |
1154 | ||
1155 | static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache) | |
1156 | { | |
1157 | return get_ref_dir(packed_ref_cache->root); | |
1158 | } | |
1159 | ||
1160 | static struct ref_dir *get_packed_refs(struct ref_cache *refs) | |
1161 | { | |
1162 | return get_packed_ref_dir(get_packed_ref_cache(refs)); | |
1163 | } | |
1164 | ||
1165 | /* | |
1166 | * Add a reference to the in-memory packed reference cache. This may | |
1167 | * only be called while the packed-refs file is locked (see | |
1168 | * lock_packed_refs()). To actually write the packed-refs file, call | |
1169 | * commit_packed_refs(). | |
1170 | */ | |
1171 | static void add_packed_ref(const char *refname, const unsigned char *sha1) | |
1172 | { | |
1173 | struct packed_ref_cache *packed_ref_cache = | |
1174 | get_packed_ref_cache(&ref_cache); | |
1175 | ||
1176 | if (!packed_ref_cache->lock) | |
1177 | die("internal error: packed refs not locked"); | |
1178 | add_ref(get_packed_ref_dir(packed_ref_cache), | |
1179 | create_ref_entry(refname, sha1, REF_ISPACKED, 1)); | |
1180 | } | |
1181 | ||
1182 | /* | |
1183 | * Read the loose references from the namespace dirname into dir | |
1184 | * (without recursing). dirname must end with '/'. dir must be the | |
1185 | * directory entry corresponding to dirname. | |
1186 | */ | |
1187 | static void read_loose_refs(const char *dirname, struct ref_dir *dir) | |
1188 | { | |
1189 | struct ref_cache *refs = dir->ref_cache; | |
1190 | DIR *d; | |
1191 | struct dirent *de; | |
1192 | int dirnamelen = strlen(dirname); | |
1193 | struct strbuf refname; | |
1194 | struct strbuf path = STRBUF_INIT; | |
1195 | size_t path_baselen; | |
1196 | ||
1197 | if (*refs->name) | |
1198 | strbuf_git_path_submodule(&path, refs->name, "%s", dirname); | |
1199 | else | |
1200 | strbuf_git_path(&path, "%s", dirname); | |
1201 | path_baselen = path.len; | |
1202 | ||
1203 | d = opendir(path.buf); | |
1204 | if (!d) { | |
1205 | strbuf_release(&path); | |
1206 | return; | |
1207 | } | |
1208 | ||
1209 | strbuf_init(&refname, dirnamelen + 257); | |
1210 | strbuf_add(&refname, dirname, dirnamelen); | |
1211 | ||
1212 | while ((de = readdir(d)) != NULL) { | |
1213 | unsigned char sha1[20]; | |
1214 | struct stat st; | |
1215 | int flag; | |
1216 | ||
1217 | if (de->d_name[0] == '.') | |
1218 | continue; | |
1219 | if (ends_with(de->d_name, ".lock")) | |
1220 | continue; | |
1221 | strbuf_addstr(&refname, de->d_name); | |
1222 | strbuf_addstr(&path, de->d_name); | |
1223 | if (stat(path.buf, &st) < 0) { | |
1224 | ; /* silently ignore */ | |
1225 | } else if (S_ISDIR(st.st_mode)) { | |
1226 | strbuf_addch(&refname, '/'); | |
1227 | add_entry_to_dir(dir, | |
1228 | create_dir_entry(refs, refname.buf, | |
1229 | refname.len, 1)); | |
1230 | } else { | |
1231 | int read_ok; | |
1232 | ||
1233 | if (*refs->name) { | |
1234 | hashclr(sha1); | |
1235 | flag = 0; | |
1236 | read_ok = !resolve_gitlink_ref(refs->name, | |
1237 | refname.buf, sha1); | |
1238 | } else { | |
1239 | read_ok = !read_ref_full(refname.buf, | |
1240 | RESOLVE_REF_READING, | |
1241 | sha1, &flag); | |
1242 | } | |
1243 | ||
1244 | if (!read_ok) { | |
1245 | hashclr(sha1); | |
1246 | flag |= REF_ISBROKEN; | |
1247 | } else if (is_null_sha1(sha1)) { | |
1248 | /* | |
1249 | * It is so astronomically unlikely | |
1250 | * that NULL_SHA1 is the SHA-1 of an | |
1251 | * actual object that we consider its | |
1252 | * appearance in a loose reference | |
1253 | * file to be repo corruption | |
1254 | * (probably due to a software bug). | |
1255 | */ | |
1256 | flag |= REF_ISBROKEN; | |
1257 | } | |
1258 | ||
1259 | if (check_refname_format(refname.buf, | |
1260 | REFNAME_ALLOW_ONELEVEL)) { | |
1261 | if (!refname_is_safe(refname.buf)) | |
1262 | die("loose refname is dangerous: %s", refname.buf); | |
1263 | hashclr(sha1); | |
1264 | flag |= REF_BAD_NAME | REF_ISBROKEN; | |
1265 | } | |
1266 | add_entry_to_dir(dir, | |
1267 | create_ref_entry(refname.buf, sha1, flag, 0)); | |
1268 | } | |
1269 | strbuf_setlen(&refname, dirnamelen); | |
1270 | strbuf_setlen(&path, path_baselen); | |
1271 | } | |
1272 | strbuf_release(&refname); | |
1273 | strbuf_release(&path); | |
1274 | closedir(d); | |
1275 | } | |
1276 | ||
1277 | static struct ref_dir *get_loose_refs(struct ref_cache *refs) | |
1278 | { | |
1279 | if (!refs->loose) { | |
1280 | /* | |
1281 | * Mark the top-level directory complete because we | |
1282 | * are about to read the only subdirectory that can | |
1283 | * hold references: | |
1284 | */ | |
1285 | refs->loose = create_dir_entry(refs, "", 0, 0); | |
1286 | /* | |
1287 | * Create an incomplete entry for "refs/": | |
1288 | */ | |
1289 | add_entry_to_dir(get_ref_dir(refs->loose), | |
1290 | create_dir_entry(refs, "refs/", 5, 1)); | |
1291 | } | |
1292 | return get_ref_dir(refs->loose); | |
1293 | } | |
1294 | ||
1295 | #define MAXREFLEN (1024) | |
1296 | ||
1297 | /* | |
1298 | * Called by resolve_gitlink_ref_recursive() after it failed to read | |
1299 | * from the loose refs in ref_cache refs. Find <refname> in the | |
1300 | * packed-refs file for the submodule. | |
1301 | */ | |
1302 | static int resolve_gitlink_packed_ref(struct ref_cache *refs, | |
1303 | const char *refname, unsigned char *sha1) | |
1304 | { | |
1305 | struct ref_entry *ref; | |
1306 | struct ref_dir *dir = get_packed_refs(refs); | |
1307 | ||
1308 | ref = find_ref(dir, refname); | |
1309 | if (ref == NULL) | |
1310 | return -1; | |
1311 | ||
1312 | hashcpy(sha1, ref->u.value.oid.hash); | |
1313 | return 0; | |
1314 | } | |
1315 | ||
1316 | static int resolve_gitlink_ref_recursive(struct ref_cache *refs, | |
1317 | const char *refname, unsigned char *sha1, | |
1318 | int recursion) | |
1319 | { | |
1320 | int fd, len; | |
1321 | char buffer[128], *p; | |
1322 | char *path; | |
1323 | ||
1324 | if (recursion > SYMREF_MAXDEPTH || strlen(refname) > MAXREFLEN) | |
1325 | return -1; | |
1326 | path = *refs->name | |
1327 | ? git_pathdup_submodule(refs->name, "%s", refname) | |
1328 | : git_pathdup("%s", refname); | |
1329 | fd = open(path, O_RDONLY); | |
1330 | free(path); | |
1331 | if (fd < 0) | |
1332 | return resolve_gitlink_packed_ref(refs, refname, sha1); | |
1333 | ||
1334 | len = read(fd, buffer, sizeof(buffer)-1); | |
1335 | close(fd); | |
1336 | if (len < 0) | |
1337 | return -1; | |
1338 | while (len && isspace(buffer[len-1])) | |
1339 | len--; | |
1340 | buffer[len] = 0; | |
1341 | ||
1342 | /* Was it a detached head or an old-fashioned symlink? */ | |
1343 | if (!get_sha1_hex(buffer, sha1)) | |
1344 | return 0; | |
1345 | ||
1346 | /* Symref? */ | |
1347 | if (strncmp(buffer, "ref:", 4)) | |
1348 | return -1; | |
1349 | p = buffer + 4; | |
1350 | while (isspace(*p)) | |
1351 | p++; | |
1352 | ||
1353 | return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1); | |
1354 | } | |
1355 | ||
1356 | int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1) | |
1357 | { | |
1358 | int len = strlen(path), retval; | |
1359 | struct strbuf submodule = STRBUF_INIT; | |
1360 | struct ref_cache *refs; | |
1361 | ||
1362 | while (len && path[len-1] == '/') | |
1363 | len--; | |
1364 | if (!len) | |
1365 | return -1; | |
1366 | ||
1367 | strbuf_add(&submodule, path, len); | |
1368 | refs = get_ref_cache(submodule.buf); | |
1369 | if (!refs) { | |
1370 | strbuf_release(&submodule); | |
1371 | return -1; | |
1372 | } | |
1373 | strbuf_release(&submodule); | |
1374 | ||
1375 | retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0); | |
1376 | return retval; | |
1377 | } | |
1378 | ||
1379 | /* | |
1380 | * Return the ref_entry for the given refname from the packed | |
1381 | * references. If it does not exist, return NULL. | |
1382 | */ | |
1383 | static struct ref_entry *get_packed_ref(const char *refname) | |
1384 | { | |
1385 | return find_ref(get_packed_refs(&ref_cache), refname); | |
1386 | } | |
1387 | ||
1388 | /* | |
1389 | * A loose ref file doesn't exist; check for a packed ref. | |
1390 | */ | |
1391 | static int resolve_missing_loose_ref(const char *refname, | |
1392 | unsigned char *sha1, | |
1393 | unsigned int *flags) | |
1394 | { | |
1395 | struct ref_entry *entry; | |
1396 | ||
1397 | /* | |
1398 | * The loose reference file does not exist; check for a packed | |
1399 | * reference. | |
1400 | */ | |
1401 | entry = get_packed_ref(refname); | |
1402 | if (entry) { | |
1403 | hashcpy(sha1, entry->u.value.oid.hash); | |
1404 | *flags |= REF_ISPACKED; | |
1405 | return 0; | |
1406 | } | |
1407 | /* refname is not a packed reference. */ | |
1408 | return -1; | |
1409 | } | |
1410 | ||
1411 | int read_raw_ref(const char *refname, unsigned char *sha1, | |
1412 | struct strbuf *referent, unsigned int *type) | |
1413 | { | |
1414 | struct strbuf sb_contents = STRBUF_INIT; | |
1415 | struct strbuf sb_path = STRBUF_INIT; | |
1416 | const char *path; | |
1417 | const char *buf; | |
1418 | struct stat st; | |
1419 | int fd; | |
1420 | int ret = -1; | |
1421 | int save_errno; | |
1422 | ||
1423 | *type = 0; | |
1424 | strbuf_reset(&sb_path); | |
1425 | strbuf_git_path(&sb_path, "%s", refname); | |
1426 | path = sb_path.buf; | |
1427 | ||
1428 | stat_ref: | |
1429 | /* | |
1430 | * We might have to loop back here to avoid a race | |
1431 | * condition: first we lstat() the file, then we try | |
1432 | * to read it as a link or as a file. But if somebody | |
1433 | * changes the type of the file (file <-> directory | |
1434 | * <-> symlink) between the lstat() and reading, then | |
1435 | * we don't want to report that as an error but rather | |
1436 | * try again starting with the lstat(). | |
1437 | */ | |
1438 | ||
1439 | if (lstat(path, &st) < 0) { | |
1440 | if (errno != ENOENT) | |
1441 | goto out; | |
1442 | if (resolve_missing_loose_ref(refname, sha1, type)) { | |
1443 | errno = ENOENT; | |
1444 | goto out; | |
1445 | } | |
1446 | ret = 0; | |
1447 | goto out; | |
1448 | } | |
1449 | ||
1450 | /* Follow "normalized" - ie "refs/.." symlinks by hand */ | |
1451 | if (S_ISLNK(st.st_mode)) { | |
1452 | strbuf_reset(&sb_contents); | |
1453 | if (strbuf_readlink(&sb_contents, path, 0) < 0) { | |
1454 | if (errno == ENOENT || errno == EINVAL) | |
1455 | /* inconsistent with lstat; retry */ | |
1456 | goto stat_ref; | |
1457 | else | |
1458 | goto out; | |
1459 | } | |
1460 | if (starts_with(sb_contents.buf, "refs/") && | |
1461 | !check_refname_format(sb_contents.buf, 0)) { | |
1462 | strbuf_swap(&sb_contents, referent); | |
1463 | *type |= REF_ISSYMREF; | |
1464 | ret = 0; | |
1465 | goto out; | |
1466 | } | |
1467 | } | |
1468 | ||
1469 | /* Is it a directory? */ | |
1470 | if (S_ISDIR(st.st_mode)) { | |
1471 | /* | |
1472 | * Even though there is a directory where the loose | |
1473 | * ref is supposed to be, there could still be a | |
1474 | * packed ref: | |
1475 | */ | |
1476 | if (resolve_missing_loose_ref(refname, sha1, type)) { | |
1477 | errno = EISDIR; | |
1478 | goto out; | |
1479 | } | |
1480 | ret = 0; | |
1481 | goto out; | |
1482 | } | |
1483 | ||
1484 | /* | |
1485 | * Anything else, just open it and try to use it as | |
1486 | * a ref | |
1487 | */ | |
1488 | fd = open(path, O_RDONLY); | |
1489 | if (fd < 0) { | |
1490 | if (errno == ENOENT) | |
1491 | /* inconsistent with lstat; retry */ | |
1492 | goto stat_ref; | |
1493 | else | |
1494 | goto out; | |
1495 | } | |
1496 | strbuf_reset(&sb_contents); | |
1497 | if (strbuf_read(&sb_contents, fd, 256) < 0) { | |
1498 | int save_errno = errno; | |
1499 | close(fd); | |
1500 | errno = save_errno; | |
1501 | goto out; | |
1502 | } | |
1503 | close(fd); | |
1504 | strbuf_rtrim(&sb_contents); | |
1505 | buf = sb_contents.buf; | |
1506 | if (starts_with(buf, "ref:")) { | |
1507 | buf += 4; | |
1508 | while (isspace(*buf)) | |
1509 | buf++; | |
1510 | ||
1511 | strbuf_reset(referent); | |
1512 | strbuf_addstr(referent, buf); | |
1513 | *type |= REF_ISSYMREF; | |
1514 | ret = 0; | |
1515 | goto out; | |
1516 | } | |
1517 | ||
1518 | /* | |
1519 | * Please note that FETCH_HEAD has additional | |
1520 | * data after the sha. | |
1521 | */ | |
1522 | if (get_sha1_hex(buf, sha1) || | |
1523 | (buf[40] != '\0' && !isspace(buf[40]))) { | |
1524 | *type |= REF_ISBROKEN; | |
1525 | errno = EINVAL; | |
1526 | goto out; | |
1527 | } | |
1528 | ||
1529 | ret = 0; | |
1530 | ||
1531 | out: | |
1532 | save_errno = errno; | |
1533 | strbuf_release(&sb_path); | |
1534 | strbuf_release(&sb_contents); | |
1535 | errno = save_errno; | |
1536 | return ret; | |
1537 | } | |
1538 | ||
1539 | static void unlock_ref(struct ref_lock *lock) | |
1540 | { | |
1541 | /* Do not free lock->lk -- atexit() still looks at them */ | |
1542 | if (lock->lk) | |
1543 | rollback_lock_file(lock->lk); | |
1544 | free(lock->ref_name); | |
1545 | free(lock); | |
1546 | } | |
1547 | ||
1548 | /* | |
1549 | * Lock refname, without following symrefs, and set *lock_p to point | |
1550 | * at a newly-allocated lock object. Fill in lock->old_oid, referent, | |
1551 | * and type similarly to read_raw_ref(). | |
1552 | * | |
1553 | * The caller must verify that refname is a "safe" reference name (in | |
1554 | * the sense of refname_is_safe()) before calling this function. | |
1555 | * | |
1556 | * If the reference doesn't already exist, verify that refname doesn't | |
1557 | * have a D/F conflict with any existing references. extras and skip | |
1558 | * are passed to verify_refname_available_dir() for this check. | |
1559 | * | |
1560 | * If mustexist is not set and the reference is not found or is | |
1561 | * broken, lock the reference anyway but clear sha1. | |
1562 | * | |
1563 | * Return 0 on success. On failure, write an error message to err and | |
1564 | * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR. | |
1565 | * | |
1566 | * Implementation note: This function is basically | |
1567 | * | |
1568 | * lock reference | |
1569 | * read_raw_ref() | |
1570 | * | |
1571 | * but it includes a lot more code to | |
1572 | * - Deal with possible races with other processes | |
1573 | * - Avoid calling verify_refname_available_dir() when it can be | |
1574 | * avoided, namely if we were successfully able to read the ref | |
1575 | * - Generate informative error messages in the case of failure | |
1576 | */ | |
1577 | static int lock_raw_ref(const char *refname, int mustexist, | |
1578 | const struct string_list *extras, | |
1579 | const struct string_list *skip, | |
1580 | struct ref_lock **lock_p, | |
1581 | struct strbuf *referent, | |
1582 | unsigned int *type, | |
1583 | struct strbuf *err) | |
1584 | { | |
1585 | struct ref_lock *lock; | |
1586 | struct strbuf ref_file = STRBUF_INIT; | |
1587 | int attempts_remaining = 3; | |
1588 | int ret = TRANSACTION_GENERIC_ERROR; | |
1589 | ||
1590 | assert(err); | |
1591 | *type = 0; | |
1592 | ||
1593 | /* First lock the file so it can't change out from under us. */ | |
1594 | ||
1595 | *lock_p = lock = xcalloc(1, sizeof(*lock)); | |
1596 | ||
1597 | lock->ref_name = xstrdup(refname); | |
1598 | strbuf_git_path(&ref_file, "%s", refname); | |
1599 | ||
1600 | retry: | |
1601 | switch (safe_create_leading_directories(ref_file.buf)) { | |
1602 | case SCLD_OK: | |
1603 | break; /* success */ | |
1604 | case SCLD_EXISTS: | |
1605 | /* | |
1606 | * Suppose refname is "refs/foo/bar". We just failed | |
1607 | * to create the containing directory, "refs/foo", | |
1608 | * because there was a non-directory in the way. This | |
1609 | * indicates a D/F conflict, probably because of | |
1610 | * another reference such as "refs/foo". There is no | |
1611 | * reason to expect this error to be transitory. | |
1612 | */ | |
1613 | if (verify_refname_available(refname, extras, skip, err)) { | |
1614 | if (mustexist) { | |
1615 | /* | |
1616 | * To the user the relevant error is | |
1617 | * that the "mustexist" reference is | |
1618 | * missing: | |
1619 | */ | |
1620 | strbuf_reset(err); | |
1621 | strbuf_addf(err, "unable to resolve reference '%s'", | |
1622 | refname); | |
1623 | } else { | |
1624 | /* | |
1625 | * The error message set by | |
1626 | * verify_refname_available_dir() is OK. | |
1627 | */ | |
1628 | ret = TRANSACTION_NAME_CONFLICT; | |
1629 | } | |
1630 | } else { | |
1631 | /* | |
1632 | * The file that is in the way isn't a loose | |
1633 | * reference. Report it as a low-level | |
1634 | * failure. | |
1635 | */ | |
1636 | strbuf_addf(err, "unable to create lock file %s.lock; " | |
1637 | "non-directory in the way", | |
1638 | ref_file.buf); | |
1639 | } | |
1640 | goto error_return; | |
1641 | case SCLD_VANISHED: | |
1642 | /* Maybe another process was tidying up. Try again. */ | |
1643 | if (--attempts_remaining > 0) | |
1644 | goto retry; | |
1645 | /* fall through */ | |
1646 | default: | |
1647 | strbuf_addf(err, "unable to create directory for %s", | |
1648 | ref_file.buf); | |
1649 | goto error_return; | |
1650 | } | |
1651 | ||
1652 | if (!lock->lk) | |
1653 | lock->lk = xcalloc(1, sizeof(struct lock_file)); | |
1654 | ||
1655 | if (hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) < 0) { | |
1656 | if (errno == ENOENT && --attempts_remaining > 0) { | |
1657 | /* | |
1658 | * Maybe somebody just deleted one of the | |
1659 | * directories leading to ref_file. Try | |
1660 | * again: | |
1661 | */ | |
1662 | goto retry; | |
1663 | } else { | |
1664 | unable_to_lock_message(ref_file.buf, errno, err); | |
1665 | goto error_return; | |
1666 | } | |
1667 | } | |
1668 | ||
1669 | /* | |
1670 | * Now we hold the lock and can read the reference without | |
1671 | * fear that its value will change. | |
1672 | */ | |
1673 | ||
1674 | if (read_raw_ref(refname, lock->old_oid.hash, referent, type)) { | |
1675 | if (errno == ENOENT) { | |
1676 | if (mustexist) { | |
1677 | /* Garden variety missing reference. */ | |
1678 | strbuf_addf(err, "unable to resolve reference '%s'", | |
1679 | refname); | |
1680 | goto error_return; | |
1681 | } else { | |
1682 | /* | |
1683 | * Reference is missing, but that's OK. We | |
1684 | * know that there is not a conflict with | |
1685 | * another loose reference because | |
1686 | * (supposing that we are trying to lock | |
1687 | * reference "refs/foo/bar"): | |
1688 | * | |
1689 | * - We were successfully able to create | |
1690 | * the lockfile refs/foo/bar.lock, so we | |
1691 | * know there cannot be a loose reference | |
1692 | * named "refs/foo". | |
1693 | * | |
1694 | * - We got ENOENT and not EISDIR, so we | |
1695 | * know that there cannot be a loose | |
1696 | * reference named "refs/foo/bar/baz". | |
1697 | */ | |
1698 | } | |
1699 | } else if (errno == EISDIR) { | |
1700 | /* | |
1701 | * There is a directory in the way. It might have | |
1702 | * contained references that have been deleted. If | |
1703 | * we don't require that the reference already | |
1704 | * exists, try to remove the directory so that it | |
1705 | * doesn't cause trouble when we want to rename the | |
1706 | * lockfile into place later. | |
1707 | */ | |
1708 | if (mustexist) { | |
1709 | /* Garden variety missing reference. */ | |
1710 | strbuf_addf(err, "unable to resolve reference '%s'", | |
1711 | refname); | |
1712 | goto error_return; | |
1713 | } else if (remove_dir_recursively(&ref_file, | |
1714 | REMOVE_DIR_EMPTY_ONLY)) { | |
1715 | if (verify_refname_available_dir( | |
1716 | refname, extras, skip, | |
1717 | get_loose_refs(&ref_cache), | |
1718 | err)) { | |
1719 | /* | |
1720 | * The error message set by | |
1721 | * verify_refname_available() is OK. | |
1722 | */ | |
1723 | ret = TRANSACTION_NAME_CONFLICT; | |
1724 | goto error_return; | |
1725 | } else { | |
1726 | /* | |
1727 | * We can't delete the directory, | |
1728 | * but we also don't know of any | |
1729 | * references that it should | |
1730 | * contain. | |
1731 | */ | |
1732 | strbuf_addf(err, "there is a non-empty directory '%s' " | |
1733 | "blocking reference '%s'", | |
1734 | ref_file.buf, refname); | |
1735 | goto error_return; | |
1736 | } | |
1737 | } | |
1738 | } else if (errno == EINVAL && (*type & REF_ISBROKEN)) { | |
1739 | strbuf_addf(err, "unable to resolve reference '%s': " | |
1740 | "reference broken", refname); | |
1741 | goto error_return; | |
1742 | } else { | |
1743 | strbuf_addf(err, "unable to resolve reference '%s': %s", | |
1744 | refname, strerror(errno)); | |
1745 | goto error_return; | |
1746 | } | |
1747 | ||
1748 | /* | |
1749 | * If the ref did not exist and we are creating it, | |
1750 | * make sure there is no existing packed ref whose | |
1751 | * name begins with our refname, nor a packed ref | |
1752 | * whose name is a proper prefix of our refname. | |
1753 | */ | |
1754 | if (verify_refname_available_dir( | |
1755 | refname, extras, skip, | |
1756 | get_packed_refs(&ref_cache), | |
1757 | err)) { | |
1758 | goto error_return; | |
1759 | } | |
1760 | } | |
1761 | ||
1762 | ret = 0; | |
1763 | goto out; | |
1764 | ||
1765 | error_return: | |
1766 | unlock_ref(lock); | |
1767 | *lock_p = NULL; | |
1768 | ||
1769 | out: | |
1770 | strbuf_release(&ref_file); | |
1771 | return ret; | |
1772 | } | |
1773 | ||
1774 | /* | |
1775 | * Peel the entry (if possible) and return its new peel_status. If | |
1776 | * repeel is true, re-peel the entry even if there is an old peeled | |
1777 | * value that is already stored in it. | |
1778 | * | |
1779 | * It is OK to call this function with a packed reference entry that | |
1780 | * might be stale and might even refer to an object that has since | |
1781 | * been garbage-collected. In such a case, if the entry has | |
1782 | * REF_KNOWS_PEELED then leave the status unchanged and return | |
1783 | * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID. | |
1784 | */ | |
1785 | static enum peel_status peel_entry(struct ref_entry *entry, int repeel) | |
1786 | { | |
1787 | enum peel_status status; | |
1788 | ||
1789 | if (entry->flag & REF_KNOWS_PEELED) { | |
1790 | if (repeel) { | |
1791 | entry->flag &= ~REF_KNOWS_PEELED; | |
1792 | oidclr(&entry->u.value.peeled); | |
1793 | } else { | |
1794 | return is_null_oid(&entry->u.value.peeled) ? | |
1795 | PEEL_NON_TAG : PEEL_PEELED; | |
1796 | } | |
1797 | } | |
1798 | if (entry->flag & REF_ISBROKEN) | |
1799 | return PEEL_BROKEN; | |
1800 | if (entry->flag & REF_ISSYMREF) | |
1801 | return PEEL_IS_SYMREF; | |
1802 | ||
1803 | status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash); | |
1804 | if (status == PEEL_PEELED || status == PEEL_NON_TAG) | |
1805 | entry->flag |= REF_KNOWS_PEELED; | |
1806 | return status; | |
1807 | } | |
1808 | ||
1809 | int peel_ref(const char *refname, unsigned char *sha1) | |
1810 | { | |
1811 | int flag; | |
1812 | unsigned char base[20]; | |
1813 | ||
1814 | if (current_ref && (current_ref->name == refname | |
1815 | || !strcmp(current_ref->name, refname))) { | |
1816 | if (peel_entry(current_ref, 0)) | |
1817 | return -1; | |
1818 | hashcpy(sha1, current_ref->u.value.peeled.hash); | |
1819 | return 0; | |
1820 | } | |
1821 | ||
1822 | if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag)) | |
1823 | return -1; | |
1824 | ||
1825 | /* | |
1826 | * If the reference is packed, read its ref_entry from the | |
1827 | * cache in the hope that we already know its peeled value. | |
1828 | * We only try this optimization on packed references because | |
1829 | * (a) forcing the filling of the loose reference cache could | |
1830 | * be expensive and (b) loose references anyway usually do not | |
1831 | * have REF_KNOWS_PEELED. | |
1832 | */ | |
1833 | if (flag & REF_ISPACKED) { | |
1834 | struct ref_entry *r = get_packed_ref(refname); | |
1835 | if (r) { | |
1836 | if (peel_entry(r, 0)) | |
1837 | return -1; | |
1838 | hashcpy(sha1, r->u.value.peeled.hash); | |
1839 | return 0; | |
1840 | } | |
1841 | } | |
1842 | ||
1843 | return peel_object(base, sha1); | |
1844 | } | |
1845 | ||
1846 | /* | |
1847 | * Call fn for each reference in the specified ref_cache, omitting | |
1848 | * references not in the containing_dir of prefix. Call fn for all | |
1849 | * references, including broken ones. If fn ever returns a non-zero | |
1850 | * value, stop the iteration and return that value; otherwise, return | |
1851 | * 0. | |
1852 | */ | |
1853 | static int do_for_each_entry(struct ref_cache *refs, const char *prefix, | |
1854 | each_ref_entry_fn fn, void *cb_data) | |
1855 | { | |
1856 | struct packed_ref_cache *packed_ref_cache; | |
1857 | struct ref_dir *loose_dir; | |
1858 | struct ref_dir *packed_dir; | |
1859 | int retval = 0; | |
1860 | ||
1861 | /* | |
1862 | * We must make sure that all loose refs are read before accessing the | |
1863 | * packed-refs file; this avoids a race condition in which loose refs | |
1864 | * are migrated to the packed-refs file by a simultaneous process, but | |
1865 | * our in-memory view is from before the migration. get_packed_ref_cache() | |
1866 | * takes care of making sure our view is up to date with what is on | |
1867 | * disk. | |
1868 | */ | |
1869 | loose_dir = get_loose_refs(refs); | |
1870 | if (prefix && *prefix) { | |
1871 | loose_dir = find_containing_dir(loose_dir, prefix, 0); | |
1872 | } | |
1873 | if (loose_dir) | |
1874 | prime_ref_dir(loose_dir); | |
1875 | ||
1876 | packed_ref_cache = get_packed_ref_cache(refs); | |
1877 | acquire_packed_ref_cache(packed_ref_cache); | |
1878 | packed_dir = get_packed_ref_dir(packed_ref_cache); | |
1879 | if (prefix && *prefix) { | |
1880 | packed_dir = find_containing_dir(packed_dir, prefix, 0); | |
1881 | } | |
1882 | ||
1883 | if (packed_dir && loose_dir) { | |
1884 | sort_ref_dir(packed_dir); | |
1885 | sort_ref_dir(loose_dir); | |
1886 | retval = do_for_each_entry_in_dirs( | |
1887 | packed_dir, loose_dir, fn, cb_data); | |
1888 | } else if (packed_dir) { | |
1889 | sort_ref_dir(packed_dir); | |
1890 | retval = do_for_each_entry_in_dir( | |
1891 | packed_dir, 0, fn, cb_data); | |
1892 | } else if (loose_dir) { | |
1893 | sort_ref_dir(loose_dir); | |
1894 | retval = do_for_each_entry_in_dir( | |
1895 | loose_dir, 0, fn, cb_data); | |
1896 | } | |
1897 | ||
1898 | release_packed_ref_cache(packed_ref_cache); | |
1899 | return retval; | |
1900 | } | |
1901 | ||
1902 | int do_for_each_ref(const char *submodule, const char *prefix, | |
1903 | each_ref_fn fn, int trim, int flags, void *cb_data) | |
1904 | { | |
1905 | struct ref_entry_cb data; | |
1906 | struct ref_cache *refs; | |
1907 | ||
1908 | refs = get_ref_cache(submodule); | |
1909 | if (!refs) | |
1910 | return 0; | |
1911 | ||
1912 | data.prefix = prefix; | |
1913 | data.trim = trim; | |
1914 | data.flags = flags; | |
1915 | data.fn = fn; | |
1916 | data.cb_data = cb_data; | |
1917 | ||
1918 | if (ref_paranoia < 0) | |
1919 | ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0); | |
1920 | if (ref_paranoia) | |
1921 | data.flags |= DO_FOR_EACH_INCLUDE_BROKEN; | |
1922 | ||
1923 | return do_for_each_entry(refs, prefix, do_one_ref, &data); | |
1924 | } | |
1925 | ||
1926 | /* | |
1927 | * Verify that the reference locked by lock has the value old_sha1. | |
1928 | * Fail if the reference doesn't exist and mustexist is set. Return 0 | |
1929 | * on success. On error, write an error message to err, set errno, and | |
1930 | * return a negative value. | |
1931 | */ | |
1932 | static int verify_lock(struct ref_lock *lock, | |
1933 | const unsigned char *old_sha1, int mustexist, | |
1934 | struct strbuf *err) | |
1935 | { | |
1936 | assert(err); | |
1937 | ||
1938 | if (read_ref_full(lock->ref_name, | |
1939 | mustexist ? RESOLVE_REF_READING : 0, | |
1940 | lock->old_oid.hash, NULL)) { | |
1941 | if (old_sha1) { | |
1942 | int save_errno = errno; | |
1943 | strbuf_addf(err, "can't verify ref '%s'", lock->ref_name); | |
1944 | errno = save_errno; | |
1945 | return -1; | |
1946 | } else { | |
1947 | hashclr(lock->old_oid.hash); | |
1948 | return 0; | |
1949 | } | |
1950 | } | |
1951 | if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) { | |
1952 | strbuf_addf(err, "ref '%s' is at %s but expected %s", | |
1953 | lock->ref_name, | |
1954 | sha1_to_hex(lock->old_oid.hash), | |
1955 | sha1_to_hex(old_sha1)); | |
1956 | errno = EBUSY; | |
1957 | return -1; | |
1958 | } | |
1959 | return 0; | |
1960 | } | |
1961 | ||
1962 | static int remove_empty_directories(struct strbuf *path) | |
1963 | { | |
1964 | /* | |
1965 | * we want to create a file but there is a directory there; | |
1966 | * if that is an empty directory (or a directory that contains | |
1967 | * only empty directories), remove them. | |
1968 | */ | |
1969 | return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY); | |
1970 | } | |
1971 | ||
1972 | /* | |
1973 | * Locks a ref returning the lock on success and NULL on failure. | |
1974 | * On failure errno is set to something meaningful. | |
1975 | */ | |
1976 | static struct ref_lock *lock_ref_sha1_basic(const char *refname, | |
1977 | const unsigned char *old_sha1, | |
1978 | const struct string_list *extras, | |
1979 | const struct string_list *skip, | |
1980 | unsigned int flags, int *type, | |
1981 | struct strbuf *err) | |
1982 | { | |
1983 | struct strbuf ref_file = STRBUF_INIT; | |
1984 | struct ref_lock *lock; | |
1985 | int last_errno = 0; | |
1986 | int lflags = LOCK_NO_DEREF; | |
1987 | int mustexist = (old_sha1 && !is_null_sha1(old_sha1)); | |
1988 | int resolve_flags = RESOLVE_REF_NO_RECURSE; | |
1989 | int attempts_remaining = 3; | |
1990 | int resolved; | |
1991 | ||
1992 | assert(err); | |
1993 | ||
1994 | lock = xcalloc(1, sizeof(struct ref_lock)); | |
1995 | ||
1996 | if (mustexist) | |
1997 | resolve_flags |= RESOLVE_REF_READING; | |
1998 | if (flags & REF_DELETING) | |
1999 | resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME; | |
2000 | ||
2001 | strbuf_git_path(&ref_file, "%s", refname); | |
2002 | resolved = !!resolve_ref_unsafe(refname, resolve_flags, | |
2003 | lock->old_oid.hash, type); | |
2004 | if (!resolved && errno == EISDIR) { | |
2005 | /* | |
2006 | * we are trying to lock foo but we used to | |
2007 | * have foo/bar which now does not exist; | |
2008 | * it is normal for the empty directory 'foo' | |
2009 | * to remain. | |
2010 | */ | |
2011 | if (remove_empty_directories(&ref_file)) { | |
2012 | last_errno = errno; | |
2013 | if (!verify_refname_available_dir(refname, extras, skip, | |
2014 | get_loose_refs(&ref_cache), err)) | |
2015 | strbuf_addf(err, "there are still refs under '%s'", | |
2016 | refname); | |
2017 | goto error_return; | |
2018 | } | |
2019 | resolved = !!resolve_ref_unsafe(refname, resolve_flags, | |
2020 | lock->old_oid.hash, type); | |
2021 | } | |
2022 | if (!resolved) { | |
2023 | last_errno = errno; | |
2024 | if (last_errno != ENOTDIR || | |
2025 | !verify_refname_available_dir(refname, extras, skip, | |
2026 | get_loose_refs(&ref_cache), err)) | |
2027 | strbuf_addf(err, "unable to resolve reference '%s': %s", | |
2028 | refname, strerror(last_errno)); | |
2029 | ||
2030 | goto error_return; | |
2031 | } | |
2032 | ||
2033 | /* | |
2034 | * If the ref did not exist and we are creating it, make sure | |
2035 | * there is no existing packed ref whose name begins with our | |
2036 | * refname, nor a packed ref whose name is a proper prefix of | |
2037 | * our refname. | |
2038 | */ | |
2039 | if (is_null_oid(&lock->old_oid) && | |
2040 | verify_refname_available_dir(refname, extras, skip, | |
2041 | get_packed_refs(&ref_cache), err)) { | |
2042 | last_errno = ENOTDIR; | |
2043 | goto error_return; | |
2044 | } | |
2045 | ||
2046 | lock->lk = xcalloc(1, sizeof(struct lock_file)); | |
2047 | ||
2048 | lock->ref_name = xstrdup(refname); | |
2049 | ||
2050 | retry: | |
2051 | switch (safe_create_leading_directories_const(ref_file.buf)) { | |
2052 | case SCLD_OK: | |
2053 | break; /* success */ | |
2054 | case SCLD_VANISHED: | |
2055 | if (--attempts_remaining > 0) | |
2056 | goto retry; | |
2057 | /* fall through */ | |
2058 | default: | |
2059 | last_errno = errno; | |
2060 | strbuf_addf(err, "unable to create directory for '%s'", | |
2061 | ref_file.buf); | |
2062 | goto error_return; | |
2063 | } | |
2064 | ||
2065 | if (hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) < 0) { | |
2066 | last_errno = errno; | |
2067 | if (errno == ENOENT && --attempts_remaining > 0) | |
2068 | /* | |
2069 | * Maybe somebody just deleted one of the | |
2070 | * directories leading to ref_file. Try | |
2071 | * again: | |
2072 | */ | |
2073 | goto retry; | |
2074 | else { | |
2075 | unable_to_lock_message(ref_file.buf, errno, err); | |
2076 | goto error_return; | |
2077 | } | |
2078 | } | |
2079 | if (verify_lock(lock, old_sha1, mustexist, err)) { | |
2080 | last_errno = errno; | |
2081 | goto error_return; | |
2082 | } | |
2083 | goto out; | |
2084 | ||
2085 | error_return: | |
2086 | unlock_ref(lock); | |
2087 | lock = NULL; | |
2088 | ||
2089 | out: | |
2090 | strbuf_release(&ref_file); | |
2091 | errno = last_errno; | |
2092 | return lock; | |
2093 | } | |
2094 | ||
2095 | /* | |
2096 | * Write an entry to the packed-refs file for the specified refname. | |
2097 | * If peeled is non-NULL, write it as the entry's peeled value. | |
2098 | */ | |
2099 | static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1, | |
2100 | unsigned char *peeled) | |
2101 | { | |
2102 | fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname); | |
2103 | if (peeled) | |
2104 | fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled)); | |
2105 | } | |
2106 | ||
2107 | /* | |
2108 | * An each_ref_entry_fn that writes the entry to a packed-refs file. | |
2109 | */ | |
2110 | static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data) | |
2111 | { | |
2112 | enum peel_status peel_status = peel_entry(entry, 0); | |
2113 | ||
2114 | if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG) | |
2115 | error("internal error: %s is not a valid packed reference!", | |
2116 | entry->name); | |
2117 | write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash, | |
2118 | peel_status == PEEL_PEELED ? | |
2119 | entry->u.value.peeled.hash : NULL); | |
2120 | return 0; | |
2121 | } | |
2122 | ||
2123 | /* | |
2124 | * Lock the packed-refs file for writing. Flags is passed to | |
2125 | * hold_lock_file_for_update(). Return 0 on success. On errors, set | |
2126 | * errno appropriately and return a nonzero value. | |
2127 | */ | |
2128 | static int lock_packed_refs(int flags) | |
2129 | { | |
2130 | static int timeout_configured = 0; | |
2131 | static int timeout_value = 1000; | |
2132 | ||
2133 | struct packed_ref_cache *packed_ref_cache; | |
2134 | ||
2135 | if (!timeout_configured) { | |
2136 | git_config_get_int("core.packedrefstimeout", &timeout_value); | |
2137 | timeout_configured = 1; | |
2138 | } | |
2139 | ||
2140 | if (hold_lock_file_for_update_timeout( | |
2141 | &packlock, git_path("packed-refs"), | |
2142 | flags, timeout_value) < 0) | |
2143 | return -1; | |
2144 | /* | |
2145 | * Get the current packed-refs while holding the lock. If the | |
2146 | * packed-refs file has been modified since we last read it, | |
2147 | * this will automatically invalidate the cache and re-read | |
2148 | * the packed-refs file. | |
2149 | */ | |
2150 | packed_ref_cache = get_packed_ref_cache(&ref_cache); | |
2151 | packed_ref_cache->lock = &packlock; | |
2152 | /* Increment the reference count to prevent it from being freed: */ | |
2153 | acquire_packed_ref_cache(packed_ref_cache); | |
2154 | return 0; | |
2155 | } | |
2156 | ||
2157 | /* | |
2158 | * Write the current version of the packed refs cache from memory to | |
2159 | * disk. The packed-refs file must already be locked for writing (see | |
2160 | * lock_packed_refs()). Return zero on success. On errors, set errno | |
2161 | * and return a nonzero value | |
2162 | */ | |
2163 | static int commit_packed_refs(void) | |
2164 | { | |
2165 | struct packed_ref_cache *packed_ref_cache = | |
2166 | get_packed_ref_cache(&ref_cache); | |
2167 | int error = 0; | |
2168 | int save_errno = 0; | |
2169 | FILE *out; | |
2170 | ||
2171 | if (!packed_ref_cache->lock) | |
2172 | die("internal error: packed-refs not locked"); | |
2173 | ||
2174 | out = fdopen_lock_file(packed_ref_cache->lock, "w"); | |
2175 | if (!out) | |
2176 | die_errno("unable to fdopen packed-refs descriptor"); | |
2177 | ||
2178 | fprintf_or_die(out, "%s", PACKED_REFS_HEADER); | |
2179 | do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache), | |
2180 | 0, write_packed_entry_fn, out); | |
2181 | ||
2182 | if (commit_lock_file(packed_ref_cache->lock)) { | |
2183 | save_errno = errno; | |
2184 | error = -1; | |
2185 | } | |
2186 | packed_ref_cache->lock = NULL; | |
2187 | release_packed_ref_cache(packed_ref_cache); | |
2188 | errno = save_errno; | |
2189 | return error; | |
2190 | } | |
2191 | ||
2192 | /* | |
2193 | * Rollback the lockfile for the packed-refs file, and discard the | |
2194 | * in-memory packed reference cache. (The packed-refs file will be | |
2195 | * read anew if it is needed again after this function is called.) | |
2196 | */ | |
2197 | static void rollback_packed_refs(void) | |
2198 | { | |
2199 | struct packed_ref_cache *packed_ref_cache = | |
2200 | get_packed_ref_cache(&ref_cache); | |
2201 | ||
2202 | if (!packed_ref_cache->lock) | |
2203 | die("internal error: packed-refs not locked"); | |
2204 | rollback_lock_file(packed_ref_cache->lock); | |
2205 | packed_ref_cache->lock = NULL; | |
2206 | release_packed_ref_cache(packed_ref_cache); | |
2207 | clear_packed_ref_cache(&ref_cache); | |
2208 | } | |
2209 | ||
2210 | struct ref_to_prune { | |
2211 | struct ref_to_prune *next; | |
2212 | unsigned char sha1[20]; | |
2213 | char name[FLEX_ARRAY]; | |
2214 | }; | |
2215 | ||
2216 | struct pack_refs_cb_data { | |
2217 | unsigned int flags; | |
2218 | struct ref_dir *packed_refs; | |
2219 | struct ref_to_prune *ref_to_prune; | |
2220 | }; | |
2221 | ||
2222 | /* | |
2223 | * An each_ref_entry_fn that is run over loose references only. If | |
2224 | * the loose reference can be packed, add an entry in the packed ref | |
2225 | * cache. If the reference should be pruned, also add it to | |
2226 | * ref_to_prune in the pack_refs_cb_data. | |
2227 | */ | |
2228 | static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data) | |
2229 | { | |
2230 | struct pack_refs_cb_data *cb = cb_data; | |
2231 | enum peel_status peel_status; | |
2232 | struct ref_entry *packed_entry; | |
2233 | int is_tag_ref = starts_with(entry->name, "refs/tags/"); | |
2234 | ||
2235 | /* Do not pack per-worktree refs: */ | |
2236 | if (ref_type(entry->name) != REF_TYPE_NORMAL) | |
2237 | return 0; | |
2238 | ||
2239 | /* ALWAYS pack tags */ | |
2240 | if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref) | |
2241 | return 0; | |
2242 | ||
2243 | /* Do not pack symbolic or broken refs: */ | |
2244 | if ((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry)) | |
2245 | return 0; | |
2246 | ||
2247 | /* Add a packed ref cache entry equivalent to the loose entry. */ | |
2248 | peel_status = peel_entry(entry, 1); | |
2249 | if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG) | |
2250 | die("internal error peeling reference %s (%s)", | |
2251 | entry->name, oid_to_hex(&entry->u.value.oid)); | |
2252 | packed_entry = find_ref(cb->packed_refs, entry->name); | |
2253 | if (packed_entry) { | |
2254 | /* Overwrite existing packed entry with info from loose entry */ | |
2255 | packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED; | |
2256 | oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid); | |
2257 | } else { | |
2258 | packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash, | |
2259 | REF_ISPACKED | REF_KNOWS_PEELED, 0); | |
2260 | add_ref(cb->packed_refs, packed_entry); | |
2261 | } | |
2262 | oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled); | |
2263 | ||
2264 | /* Schedule the loose reference for pruning if requested. */ | |
2265 | if ((cb->flags & PACK_REFS_PRUNE)) { | |
2266 | struct ref_to_prune *n; | |
2267 | FLEX_ALLOC_STR(n, name, entry->name); | |
2268 | hashcpy(n->sha1, entry->u.value.oid.hash); | |
2269 | n->next = cb->ref_to_prune; | |
2270 | cb->ref_to_prune = n; | |
2271 | } | |
2272 | return 0; | |
2273 | } | |
2274 | ||
2275 | /* | |
2276 | * Remove empty parents, but spare refs/ and immediate subdirs. | |
2277 | * Note: munges *name. | |
2278 | */ | |
2279 | static void try_remove_empty_parents(char *name) | |
2280 | { | |
2281 | char *p, *q; | |
2282 | int i; | |
2283 | p = name; | |
2284 | for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */ | |
2285 | while (*p && *p != '/') | |
2286 | p++; | |
2287 | /* tolerate duplicate slashes; see check_refname_format() */ | |
2288 | while (*p == '/') | |
2289 | p++; | |
2290 | } | |
2291 | for (q = p; *q; q++) | |
2292 | ; | |
2293 | while (1) { | |
2294 | while (q > p && *q != '/') | |
2295 | q--; | |
2296 | while (q > p && *(q-1) == '/') | |
2297 | q--; | |
2298 | if (q == p) | |
2299 | break; | |
2300 | *q = '\0'; | |
2301 | if (rmdir(git_path("%s", name))) | |
2302 | break; | |
2303 | } | |
2304 | } | |
2305 | ||
2306 | /* make sure nobody touched the ref, and unlink */ | |
2307 | static void prune_ref(struct ref_to_prune *r) | |
2308 | { | |
2309 | struct ref_transaction *transaction; | |
2310 | struct strbuf err = STRBUF_INIT; | |
2311 | ||
2312 | if (check_refname_format(r->name, 0)) | |
2313 | return; | |
2314 | ||
2315 | transaction = ref_transaction_begin(&err); | |
2316 | if (!transaction || | |
2317 | ref_transaction_delete(transaction, r->name, r->sha1, | |
2318 | REF_ISPRUNING | REF_NODEREF, NULL, &err) || | |
2319 | ref_transaction_commit(transaction, &err)) { | |
2320 | ref_transaction_free(transaction); | |
2321 | error("%s", err.buf); | |
2322 | strbuf_release(&err); | |
2323 | return; | |
2324 | } | |
2325 | ref_transaction_free(transaction); | |
2326 | strbuf_release(&err); | |
2327 | try_remove_empty_parents(r->name); | |
2328 | } | |
2329 | ||
2330 | static void prune_refs(struct ref_to_prune *r) | |
2331 | { | |
2332 | while (r) { | |
2333 | prune_ref(r); | |
2334 | r = r->next; | |
2335 | } | |
2336 | } | |
2337 | ||
2338 | int pack_refs(unsigned int flags) | |
2339 | { | |
2340 | struct pack_refs_cb_data cbdata; | |
2341 | ||
2342 | memset(&cbdata, 0, sizeof(cbdata)); | |
2343 | cbdata.flags = flags; | |
2344 | ||
2345 | lock_packed_refs(LOCK_DIE_ON_ERROR); | |
2346 | cbdata.packed_refs = get_packed_refs(&ref_cache); | |
2347 | ||
2348 | do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0, | |
2349 | pack_if_possible_fn, &cbdata); | |
2350 | ||
2351 | if (commit_packed_refs()) | |
2352 | die_errno("unable to overwrite old ref-pack file"); | |
2353 | ||
2354 | prune_refs(cbdata.ref_to_prune); | |
2355 | return 0; | |
2356 | } | |
2357 | ||
2358 | /* | |
2359 | * Rewrite the packed-refs file, omitting any refs listed in | |
2360 | * 'refnames'. On error, leave packed-refs unchanged, write an error | |
2361 | * message to 'err', and return a nonzero value. | |
2362 | * | |
2363 | * The refs in 'refnames' needn't be sorted. `err` must not be NULL. | |
2364 | */ | |
2365 | static int repack_without_refs(struct string_list *refnames, struct strbuf *err) | |
2366 | { | |
2367 | struct ref_dir *packed; | |
2368 | struct string_list_item *refname; | |
2369 | int ret, needs_repacking = 0, removed = 0; | |
2370 | ||
2371 | assert(err); | |
2372 | ||
2373 | /* Look for a packed ref */ | |
2374 | for_each_string_list_item(refname, refnames) { | |
2375 | if (get_packed_ref(refname->string)) { | |
2376 | needs_repacking = 1; | |
2377 | break; | |
2378 | } | |
2379 | } | |
2380 | ||
2381 | /* Avoid locking if we have nothing to do */ | |
2382 | if (!needs_repacking) | |
2383 | return 0; /* no refname exists in packed refs */ | |
2384 | ||
2385 | if (lock_packed_refs(0)) { | |
2386 | unable_to_lock_message(git_path("packed-refs"), errno, err); | |
2387 | return -1; | |
2388 | } | |
2389 | packed = get_packed_refs(&ref_cache); | |
2390 | ||
2391 | /* Remove refnames from the cache */ | |
2392 | for_each_string_list_item(refname, refnames) | |
2393 | if (remove_entry(packed, refname->string) != -1) | |
2394 | removed = 1; | |
2395 | if (!removed) { | |
2396 | /* | |
2397 | * All packed entries disappeared while we were | |
2398 | * acquiring the lock. | |
2399 | */ | |
2400 | rollback_packed_refs(); | |
2401 | return 0; | |
2402 | } | |
2403 | ||
2404 | /* Write what remains */ | |
2405 | ret = commit_packed_refs(); | |
2406 | if (ret) | |
2407 | strbuf_addf(err, "unable to overwrite old ref-pack file: %s", | |
2408 | strerror(errno)); | |
2409 | return ret; | |
2410 | } | |
2411 | ||
2412 | static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err) | |
2413 | { | |
2414 | assert(err); | |
2415 | ||
2416 | if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) { | |
2417 | /* | |
2418 | * loose. The loose file name is the same as the | |
2419 | * lockfile name, minus ".lock": | |
2420 | */ | |
2421 | char *loose_filename = get_locked_file_path(lock->lk); | |
2422 | int res = unlink_or_msg(loose_filename, err); | |
2423 | free(loose_filename); | |
2424 | if (res) | |
2425 | return 1; | |
2426 | } | |
2427 | return 0; | |
2428 | } | |
2429 | ||
2430 | int delete_refs(struct string_list *refnames, unsigned int flags) | |
2431 | { | |
2432 | struct strbuf err = STRBUF_INIT; | |
2433 | int i, result = 0; | |
2434 | ||
2435 | if (!refnames->nr) | |
2436 | return 0; | |
2437 | ||
2438 | result = repack_without_refs(refnames, &err); | |
2439 | if (result) { | |
2440 | /* | |
2441 | * If we failed to rewrite the packed-refs file, then | |
2442 | * it is unsafe to try to remove loose refs, because | |
2443 | * doing so might expose an obsolete packed value for | |
2444 | * a reference that might even point at an object that | |
2445 | * has been garbage collected. | |
2446 | */ | |
2447 | if (refnames->nr == 1) | |
2448 | error(_("could not delete reference %s: %s"), | |
2449 | refnames->items[0].string, err.buf); | |
2450 | else | |
2451 | error(_("could not delete references: %s"), err.buf); | |
2452 | ||
2453 | goto out; | |
2454 | } | |
2455 | ||
2456 | for (i = 0; i < refnames->nr; i++) { | |
2457 | const char *refname = refnames->items[i].string; | |
2458 | ||
2459 | if (delete_ref(refname, NULL, flags)) | |
2460 | result |= error(_("could not remove reference %s"), refname); | |
2461 | } | |
2462 | ||
2463 | out: | |
2464 | strbuf_release(&err); | |
2465 | return result; | |
2466 | } | |
2467 | ||
2468 | /* | |
2469 | * People using contrib's git-new-workdir have .git/logs/refs -> | |
2470 | * /some/other/path/.git/logs/refs, and that may live on another device. | |
2471 | * | |
2472 | * IOW, to avoid cross device rename errors, the temporary renamed log must | |
2473 | * live into logs/refs. | |
2474 | */ | |
2475 | #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log" | |
2476 | ||
2477 | static int rename_tmp_log(const char *newrefname) | |
2478 | { | |
2479 | int attempts_remaining = 4; | |
2480 | struct strbuf path = STRBUF_INIT; | |
2481 | int ret = -1; | |
2482 | ||
2483 | retry: | |
2484 | strbuf_reset(&path); | |
2485 | strbuf_git_path(&path, "logs/%s", newrefname); | |
2486 | switch (safe_create_leading_directories_const(path.buf)) { | |
2487 | case SCLD_OK: | |
2488 | break; /* success */ | |
2489 | case SCLD_VANISHED: | |
2490 | if (--attempts_remaining > 0) | |
2491 | goto retry; | |
2492 | /* fall through */ | |
2493 | default: | |
2494 | error("unable to create directory for %s", newrefname); | |
2495 | goto out; | |
2496 | } | |
2497 | ||
2498 | if (rename(git_path(TMP_RENAMED_LOG), path.buf)) { | |
2499 | if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) { | |
2500 | /* | |
2501 | * rename(a, b) when b is an existing | |
2502 | * directory ought to result in ISDIR, but | |
2503 | * Solaris 5.8 gives ENOTDIR. Sheesh. | |
2504 | */ | |
2505 | if (remove_empty_directories(&path)) { | |
2506 | error("Directory not empty: logs/%s", newrefname); | |
2507 | goto out; | |
2508 | } | |
2509 | goto retry; | |
2510 | } else if (errno == ENOENT && --attempts_remaining > 0) { | |
2511 | /* | |
2512 | * Maybe another process just deleted one of | |
2513 | * the directories in the path to newrefname. | |
2514 | * Try again from the beginning. | |
2515 | */ | |
2516 | goto retry; | |
2517 | } else { | |
2518 | error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s", | |
2519 | newrefname, strerror(errno)); | |
2520 | goto out; | |
2521 | } | |
2522 | } | |
2523 | ret = 0; | |
2524 | out: | |
2525 | strbuf_release(&path); | |
2526 | return ret; | |
2527 | } | |
2528 | ||
2529 | int verify_refname_available(const char *newname, | |
2530 | const struct string_list *extras, | |
2531 | const struct string_list *skip, | |
2532 | struct strbuf *err) | |
2533 | { | |
2534 | struct ref_dir *packed_refs = get_packed_refs(&ref_cache); | |
2535 | struct ref_dir *loose_refs = get_loose_refs(&ref_cache); | |
2536 | ||
2537 | if (verify_refname_available_dir(newname, extras, skip, | |
2538 | packed_refs, err) || | |
2539 | verify_refname_available_dir(newname, extras, skip, | |
2540 | loose_refs, err)) | |
2541 | return -1; | |
2542 | ||
2543 | return 0; | |
2544 | } | |
2545 | ||
2546 | static int write_ref_to_lockfile(struct ref_lock *lock, | |
2547 | const unsigned char *sha1, struct strbuf *err); | |
2548 | static int commit_ref_update(struct ref_lock *lock, | |
2549 | const unsigned char *sha1, const char *logmsg, | |
2550 | struct strbuf *err); | |
2551 | ||
2552 | int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg) | |
2553 | { | |
2554 | unsigned char sha1[20], orig_sha1[20]; | |
2555 | int flag = 0, logmoved = 0; | |
2556 | struct ref_lock *lock; | |
2557 | struct stat loginfo; | |
2558 | int log = !lstat(git_path("logs/%s", oldrefname), &loginfo); | |
2559 | struct strbuf err = STRBUF_INIT; | |
2560 | ||
2561 | if (log && S_ISLNK(loginfo.st_mode)) | |
2562 | return error("reflog for %s is a symlink", oldrefname); | |
2563 | ||
2564 | if (!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE, | |
2565 | orig_sha1, &flag)) | |
2566 | return error("refname %s not found", oldrefname); | |
2567 | ||
2568 | if (flag & REF_ISSYMREF) | |
2569 | return error("refname %s is a symbolic ref, renaming it is not supported", | |
2570 | oldrefname); | |
2571 | if (!rename_ref_available(oldrefname, newrefname)) | |
2572 | return 1; | |
2573 | ||
2574 | if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG))) | |
2575 | return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s", | |
2576 | oldrefname, strerror(errno)); | |
2577 | ||
2578 | if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) { | |
2579 | error("unable to delete old %s", oldrefname); | |
2580 | goto rollback; | |
2581 | } | |
2582 | ||
2583 | /* | |
2584 | * Since we are doing a shallow lookup, sha1 is not the | |
2585 | * correct value to pass to delete_ref as old_sha1. But that | |
2586 | * doesn't matter, because an old_sha1 check wouldn't add to | |
2587 | * the safety anyway; we want to delete the reference whatever | |
2588 | * its current value. | |
2589 | */ | |
2590 | if (!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE, | |
2591 | sha1, NULL) && | |
2592 | delete_ref(newrefname, NULL, REF_NODEREF)) { | |
2593 | if (errno==EISDIR) { | |
2594 | struct strbuf path = STRBUF_INIT; | |
2595 | int result; | |
2596 | ||
2597 | strbuf_git_path(&path, "%s", newrefname); | |
2598 | result = remove_empty_directories(&path); | |
2599 | strbuf_release(&path); | |
2600 | ||
2601 | if (result) { | |
2602 | error("Directory not empty: %s", newrefname); | |
2603 | goto rollback; | |
2604 | } | |
2605 | } else { | |
2606 | error("unable to delete existing %s", newrefname); | |
2607 | goto rollback; | |
2608 | } | |
2609 | } | |
2610 | ||
2611 | if (log && rename_tmp_log(newrefname)) | |
2612 | goto rollback; | |
2613 | ||
2614 | logmoved = log; | |
2615 | ||
2616 | lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, REF_NODEREF, | |
2617 | NULL, &err); | |
2618 | if (!lock) { | |
2619 | error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf); | |
2620 | strbuf_release(&err); | |
2621 | goto rollback; | |
2622 | } | |
2623 | hashcpy(lock->old_oid.hash, orig_sha1); | |
2624 | ||
2625 | if (write_ref_to_lockfile(lock, orig_sha1, &err) || | |
2626 | commit_ref_update(lock, orig_sha1, logmsg, &err)) { | |
2627 | error("unable to write current sha1 into %s: %s", newrefname, err.buf); | |
2628 | strbuf_release(&err); | |
2629 | goto rollback; | |
2630 | } | |
2631 | ||
2632 | return 0; | |
2633 | ||
2634 | rollback: | |
2635 | lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, REF_NODEREF, | |
2636 | NULL, &err); | |
2637 | if (!lock) { | |
2638 | error("unable to lock %s for rollback: %s", oldrefname, err.buf); | |
2639 | strbuf_release(&err); | |
2640 | goto rollbacklog; | |
2641 | } | |
2642 | ||
2643 | flag = log_all_ref_updates; | |
2644 | log_all_ref_updates = 0; | |
2645 | if (write_ref_to_lockfile(lock, orig_sha1, &err) || | |
2646 | commit_ref_update(lock, orig_sha1, NULL, &err)) { | |
2647 | error("unable to write current sha1 into %s: %s", oldrefname, err.buf); | |
2648 | strbuf_release(&err); | |
2649 | } | |
2650 | log_all_ref_updates = flag; | |
2651 | ||
2652 | rollbacklog: | |
2653 | if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname))) | |
2654 | error("unable to restore logfile %s from %s: %s", | |
2655 | oldrefname, newrefname, strerror(errno)); | |
2656 | if (!logmoved && log && | |
2657 | rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname))) | |
2658 | error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s", | |
2659 | oldrefname, strerror(errno)); | |
2660 | ||
2661 | return 1; | |
2662 | } | |
2663 | ||
2664 | static int close_ref(struct ref_lock *lock) | |
2665 | { | |
2666 | if (close_lock_file(lock->lk)) | |
2667 | return -1; | |
2668 | return 0; | |
2669 | } | |
2670 | ||
2671 | static int commit_ref(struct ref_lock *lock) | |
2672 | { | |
2673 | char *path = get_locked_file_path(lock->lk); | |
2674 | struct stat st; | |
2675 | ||
2676 | if (!lstat(path, &st) && S_ISDIR(st.st_mode)) { | |
2677 | /* | |
2678 | * There is a directory at the path we want to rename | |
2679 | * the lockfile to. Hopefully it is empty; try to | |
2680 | * delete it. | |
2681 | */ | |
2682 | size_t len = strlen(path); | |
2683 | struct strbuf sb_path = STRBUF_INIT; | |
2684 | ||
2685 | strbuf_attach(&sb_path, path, len, len); | |
2686 | ||
2687 | /* | |
2688 | * If this fails, commit_lock_file() will also fail | |
2689 | * and will report the problem. | |
2690 | */ | |
2691 | remove_empty_directories(&sb_path); | |
2692 | strbuf_release(&sb_path); | |
2693 | } else { | |
2694 | free(path); | |
2695 | } | |
2696 | ||
2697 | if (commit_lock_file(lock->lk)) | |
2698 | return -1; | |
2699 | return 0; | |
2700 | } | |
2701 | ||
2702 | /* | |
2703 | * Create a reflog for a ref. If force_create = 0, the reflog will | |
2704 | * only be created for certain refs (those for which | |
2705 | * should_autocreate_reflog returns non-zero. Otherwise, create it | |
2706 | * regardless of the ref name. Fill in *err and return -1 on failure. | |
2707 | */ | |
2708 | static int log_ref_setup(const char *refname, struct strbuf *logfile, struct strbuf *err, int force_create) | |
2709 | { | |
2710 | int logfd, oflags = O_APPEND | O_WRONLY; | |
2711 | ||
2712 | strbuf_git_path(logfile, "logs/%s", refname); | |
2713 | if (force_create || should_autocreate_reflog(refname)) { | |
2714 | if (safe_create_leading_directories(logfile->buf) < 0) { | |
2715 | strbuf_addf(err, "unable to create directory for '%s': " | |
2716 | "%s", logfile->buf, strerror(errno)); | |
2717 | return -1; | |
2718 | } | |
2719 | oflags |= O_CREAT; | |
2720 | } | |
2721 | ||
2722 | logfd = open(logfile->buf, oflags, 0666); | |
2723 | if (logfd < 0) { | |
2724 | if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR)) | |
2725 | return 0; | |
2726 | ||
2727 | if (errno == EISDIR) { | |
2728 | if (remove_empty_directories(logfile)) { | |
2729 | strbuf_addf(err, "there are still logs under " | |
2730 | "'%s'", logfile->buf); | |
2731 | return -1; | |
2732 | } | |
2733 | logfd = open(logfile->buf, oflags, 0666); | |
2734 | } | |
2735 | ||
2736 | if (logfd < 0) { | |
2737 | strbuf_addf(err, "unable to append to '%s': %s", | |
2738 | logfile->buf, strerror(errno)); | |
2739 | return -1; | |
2740 | } | |
2741 | } | |
2742 | ||
2743 | adjust_shared_perm(logfile->buf); | |
2744 | close(logfd); | |
2745 | return 0; | |
2746 | } | |
2747 | ||
2748 | ||
2749 | int safe_create_reflog(const char *refname, int force_create, struct strbuf *err) | |
2750 | { | |
2751 | int ret; | |
2752 | struct strbuf sb = STRBUF_INIT; | |
2753 | ||
2754 | ret = log_ref_setup(refname, &sb, err, force_create); | |
2755 | strbuf_release(&sb); | |
2756 | return ret; | |
2757 | } | |
2758 | ||
2759 | static int log_ref_write_fd(int fd, const unsigned char *old_sha1, | |
2760 | const unsigned char *new_sha1, | |
2761 | const char *committer, const char *msg) | |
2762 | { | |
2763 | int msglen, written; | |
2764 | unsigned maxlen, len; | |
2765 | char *logrec; | |
2766 | ||
2767 | msglen = msg ? strlen(msg) : 0; | |
2768 | maxlen = strlen(committer) + msglen + 100; | |
2769 | logrec = xmalloc(maxlen); | |
2770 | len = xsnprintf(logrec, maxlen, "%s %s %s\n", | |
2771 | sha1_to_hex(old_sha1), | |
2772 | sha1_to_hex(new_sha1), | |
2773 | committer); | |
2774 | if (msglen) | |
2775 | len += copy_reflog_msg(logrec + len - 1, msg) - 1; | |
2776 | ||
2777 | written = len <= maxlen ? write_in_full(fd, logrec, len) : -1; | |
2778 | free(logrec); | |
2779 | if (written != len) | |
2780 | return -1; | |
2781 | ||
2782 | return 0; | |
2783 | } | |
2784 | ||
2785 | static int log_ref_write_1(const char *refname, const unsigned char *old_sha1, | |
2786 | const unsigned char *new_sha1, const char *msg, | |
2787 | struct strbuf *logfile, int flags, | |
2788 | struct strbuf *err) | |
2789 | { | |
2790 | int logfd, result, oflags = O_APPEND | O_WRONLY; | |
2791 | ||
2792 | if (log_all_ref_updates < 0) | |
2793 | log_all_ref_updates = !is_bare_repository(); | |
2794 | ||
2795 | result = log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG); | |
2796 | ||
2797 | if (result) | |
2798 | return result; | |
2799 | ||
2800 | logfd = open(logfile->buf, oflags); | |
2801 | if (logfd < 0) | |
2802 | return 0; | |
2803 | result = log_ref_write_fd(logfd, old_sha1, new_sha1, | |
2804 | git_committer_info(0), msg); | |
2805 | if (result) { | |
2806 | strbuf_addf(err, "unable to append to '%s': %s", logfile->buf, | |
2807 | strerror(errno)); | |
2808 | close(logfd); | |
2809 | return -1; | |
2810 | } | |
2811 | if (close(logfd)) { | |
2812 | strbuf_addf(err, "unable to append to '%s': %s", logfile->buf, | |
2813 | strerror(errno)); | |
2814 | return -1; | |
2815 | } | |
2816 | return 0; | |
2817 | } | |
2818 | ||
2819 | static int log_ref_write(const char *refname, const unsigned char *old_sha1, | |
2820 | const unsigned char *new_sha1, const char *msg, | |
2821 | int flags, struct strbuf *err) | |
2822 | { | |
2823 | return files_log_ref_write(refname, old_sha1, new_sha1, msg, flags, | |
2824 | err); | |
2825 | } | |
2826 | ||
2827 | int files_log_ref_write(const char *refname, const unsigned char *old_sha1, | |
2828 | const unsigned char *new_sha1, const char *msg, | |
2829 | int flags, struct strbuf *err) | |
2830 | { | |
2831 | struct strbuf sb = STRBUF_INIT; | |
2832 | int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags, | |
2833 | err); | |
2834 | strbuf_release(&sb); | |
2835 | return ret; | |
2836 | } | |
2837 | ||
2838 | /* | |
2839 | * Write sha1 into the open lockfile, then close the lockfile. On | |
2840 | * errors, rollback the lockfile, fill in *err and | |
2841 | * return -1. | |
2842 | */ | |
2843 | static int write_ref_to_lockfile(struct ref_lock *lock, | |
2844 | const unsigned char *sha1, struct strbuf *err) | |
2845 | { | |
2846 | static char term = '\n'; | |
2847 | struct object *o; | |
2848 | int fd; | |
2849 | ||
2850 | o = parse_object(sha1); | |
2851 | if (!o) { | |
2852 | strbuf_addf(err, | |
2853 | "trying to write ref '%s' with nonexistent object %s", | |
2854 | lock->ref_name, sha1_to_hex(sha1)); | |
2855 | unlock_ref(lock); | |
2856 | return -1; | |
2857 | } | |
2858 | if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) { | |
2859 | strbuf_addf(err, | |
2860 | "trying to write non-commit object %s to branch '%s'", | |
2861 | sha1_to_hex(sha1), lock->ref_name); | |
2862 | unlock_ref(lock); | |
2863 | return -1; | |
2864 | } | |
2865 | fd = get_lock_file_fd(lock->lk); | |
2866 | if (write_in_full(fd, sha1_to_hex(sha1), 40) != 40 || | |
2867 | write_in_full(fd, &term, 1) != 1 || | |
2868 | close_ref(lock) < 0) { | |
2869 | strbuf_addf(err, | |
2870 | "couldn't write '%s'", get_lock_file_path(lock->lk)); | |
2871 | unlock_ref(lock); | |
2872 | return -1; | |
2873 | } | |
2874 | return 0; | |
2875 | } | |
2876 | ||
2877 | /* | |
2878 | * Commit a change to a loose reference that has already been written | |
2879 | * to the loose reference lockfile. Also update the reflogs if | |
2880 | * necessary, using the specified lockmsg (which can be NULL). | |
2881 | */ | |
2882 | static int commit_ref_update(struct ref_lock *lock, | |
2883 | const unsigned char *sha1, const char *logmsg, | |
2884 | struct strbuf *err) | |
2885 | { | |
2886 | clear_loose_ref_cache(&ref_cache); | |
2887 | if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, 0, err)) { | |
2888 | char *old_msg = strbuf_detach(err, NULL); | |
2889 | strbuf_addf(err, "cannot update the ref '%s': %s", | |
2890 | lock->ref_name, old_msg); | |
2891 | free(old_msg); | |
2892 | unlock_ref(lock); | |
2893 | return -1; | |
2894 | } | |
2895 | ||
2896 | if (strcmp(lock->ref_name, "HEAD") != 0) { | |
2897 | /* | |
2898 | * Special hack: If a branch is updated directly and HEAD | |
2899 | * points to it (may happen on the remote side of a push | |
2900 | * for example) then logically the HEAD reflog should be | |
2901 | * updated too. | |
2902 | * A generic solution implies reverse symref information, | |
2903 | * but finding all symrefs pointing to the given branch | |
2904 | * would be rather costly for this rare event (the direct | |
2905 | * update of a branch) to be worth it. So let's cheat and | |
2906 | * check with HEAD only which should cover 99% of all usage | |
2907 | * scenarios (even 100% of the default ones). | |
2908 | */ | |
2909 | unsigned char head_sha1[20]; | |
2910 | int head_flag; | |
2911 | const char *head_ref; | |
2912 | ||
2913 | head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, | |
2914 | head_sha1, &head_flag); | |
2915 | if (head_ref && (head_flag & REF_ISSYMREF) && | |
2916 | !strcmp(head_ref, lock->ref_name)) { | |
2917 | struct strbuf log_err = STRBUF_INIT; | |
2918 | if (log_ref_write("HEAD", lock->old_oid.hash, sha1, | |
2919 | logmsg, 0, &log_err)) { | |
2920 | error("%s", log_err.buf); | |
2921 | strbuf_release(&log_err); | |
2922 | } | |
2923 | } | |
2924 | } | |
2925 | ||
2926 | if (commit_ref(lock)) { | |
2927 | strbuf_addf(err, "couldn't set '%s'", lock->ref_name); | |
2928 | unlock_ref(lock); | |
2929 | return -1; | |
2930 | } | |
2931 | ||
2932 | unlock_ref(lock); | |
2933 | return 0; | |
2934 | } | |
2935 | ||
2936 | static int create_ref_symlink(struct ref_lock *lock, const char *target) | |
2937 | { | |
2938 | int ret = -1; | |
2939 | #ifndef NO_SYMLINK_HEAD | |
2940 | char *ref_path = get_locked_file_path(lock->lk); | |
2941 | unlink(ref_path); | |
2942 | ret = symlink(target, ref_path); | |
2943 | free(ref_path); | |
2944 | ||
2945 | if (ret) | |
2946 | fprintf(stderr, "no symlink - falling back to symbolic ref\n"); | |
2947 | #endif | |
2948 | return ret; | |
2949 | } | |
2950 | ||
2951 | static void update_symref_reflog(struct ref_lock *lock, const char *refname, | |
2952 | const char *target, const char *logmsg) | |
2953 | { | |
2954 | struct strbuf err = STRBUF_INIT; | |
2955 | unsigned char new_sha1[20]; | |
2956 | if (logmsg && !read_ref(target, new_sha1) && | |
2957 | log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg, 0, &err)) { | |
2958 | error("%s", err.buf); | |
2959 | strbuf_release(&err); | |
2960 | } | |
2961 | } | |
2962 | ||
2963 | static int create_symref_locked(struct ref_lock *lock, const char *refname, | |
2964 | const char *target, const char *logmsg) | |
2965 | { | |
2966 | if (prefer_symlink_refs && !create_ref_symlink(lock, target)) { | |
2967 | update_symref_reflog(lock, refname, target, logmsg); | |
2968 | return 0; | |
2969 | } | |
2970 | ||
2971 | if (!fdopen_lock_file(lock->lk, "w")) | |
2972 | return error("unable to fdopen %s: %s", | |
2973 | lock->lk->tempfile.filename.buf, strerror(errno)); | |
2974 | ||
2975 | update_symref_reflog(lock, refname, target, logmsg); | |
2976 | ||
2977 | /* no error check; commit_ref will check ferror */ | |
2978 | fprintf(lock->lk->tempfile.fp, "ref: %s\n", target); | |
2979 | if (commit_ref(lock) < 0) | |
2980 | return error("unable to write symref for %s: %s", refname, | |
2981 | strerror(errno)); | |
2982 | return 0; | |
2983 | } | |
2984 | ||
2985 | int create_symref(const char *refname, const char *target, const char *logmsg) | |
2986 | { | |
2987 | struct strbuf err = STRBUF_INIT; | |
2988 | struct ref_lock *lock; | |
2989 | int ret; | |
2990 | ||
2991 | lock = lock_ref_sha1_basic(refname, NULL, NULL, NULL, REF_NODEREF, NULL, | |
2992 | &err); | |
2993 | if (!lock) { | |
2994 | error("%s", err.buf); | |
2995 | strbuf_release(&err); | |
2996 | return -1; | |
2997 | } | |
2998 | ||
2999 | ret = create_symref_locked(lock, refname, target, logmsg); | |
3000 | unlock_ref(lock); | |
3001 | return ret; | |
3002 | } | |
3003 | ||
3004 | int set_worktree_head_symref(const char *gitdir, const char *target) | |
3005 | { | |
3006 | static struct lock_file head_lock; | |
3007 | struct ref_lock *lock; | |
3008 | struct strbuf head_path = STRBUF_INIT; | |
3009 | const char *head_rel; | |
3010 | int ret; | |
3011 | ||
3012 | strbuf_addf(&head_path, "%s/HEAD", absolute_path(gitdir)); | |
3013 | if (hold_lock_file_for_update(&head_lock, head_path.buf, | |
3014 | LOCK_NO_DEREF) < 0) { | |
3015 | struct strbuf err = STRBUF_INIT; | |
3016 | unable_to_lock_message(head_path.buf, errno, &err); | |
3017 | error("%s", err.buf); | |
3018 | strbuf_release(&err); | |
3019 | strbuf_release(&head_path); | |
3020 | return -1; | |
3021 | } | |
3022 | ||
3023 | /* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for | |
3024 | linked trees */ | |
3025 | head_rel = remove_leading_path(head_path.buf, | |
3026 | absolute_path(get_git_common_dir())); | |
3027 | /* to make use of create_symref_locked(), initialize ref_lock */ | |
3028 | lock = xcalloc(1, sizeof(struct ref_lock)); | |
3029 | lock->lk = &head_lock; | |
3030 | lock->ref_name = xstrdup(head_rel); | |
3031 | ||
3032 | ret = create_symref_locked(lock, head_rel, target, NULL); | |
3033 | ||
3034 | unlock_ref(lock); /* will free lock */ | |
3035 | strbuf_release(&head_path); | |
3036 | return ret; | |
3037 | } | |
3038 | ||
3039 | int reflog_exists(const char *refname) | |
3040 | { | |
3041 | struct stat st; | |
3042 | ||
3043 | return !lstat(git_path("logs/%s", refname), &st) && | |
3044 | S_ISREG(st.st_mode); | |
3045 | } | |
3046 | ||
3047 | int delete_reflog(const char *refname) | |
3048 | { | |
3049 | return remove_path(git_path("logs/%s", refname)); | |
3050 | } | |
3051 | ||
3052 | static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data) | |
3053 | { | |
3054 | unsigned char osha1[20], nsha1[20]; | |
3055 | char *email_end, *message; | |
3056 | unsigned long timestamp; | |
3057 | int tz; | |
3058 | ||
3059 | /* old SP new SP name <email> SP time TAB msg LF */ | |
3060 | if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' || | |
3061 | get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' || | |
3062 | get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' || | |
3063 | !(email_end = strchr(sb->buf + 82, '>')) || | |
3064 | email_end[1] != ' ' || | |
3065 | !(timestamp = strtoul(email_end + 2, &message, 10)) || | |
3066 | !message || message[0] != ' ' || | |
3067 | (message[1] != '+' && message[1] != '-') || | |
3068 | !isdigit(message[2]) || !isdigit(message[3]) || | |
3069 | !isdigit(message[4]) || !isdigit(message[5])) | |
3070 | return 0; /* corrupt? */ | |
3071 | email_end[1] = '\0'; | |
3072 | tz = strtol(message + 1, NULL, 10); | |
3073 | if (message[6] != '\t') | |
3074 | message += 6; | |
3075 | else | |
3076 | message += 7; | |
3077 | return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data); | |
3078 | } | |
3079 | ||
3080 | static char *find_beginning_of_line(char *bob, char *scan) | |
3081 | { | |
3082 | while (bob < scan && *(--scan) != '\n') | |
3083 | ; /* keep scanning backwards */ | |
3084 | /* | |
3085 | * Return either beginning of the buffer, or LF at the end of | |
3086 | * the previous line. | |
3087 | */ | |
3088 | return scan; | |
3089 | } | |
3090 | ||
3091 | int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data) | |
3092 | { | |
3093 | struct strbuf sb = STRBUF_INIT; | |
3094 | FILE *logfp; | |
3095 | long pos; | |
3096 | int ret = 0, at_tail = 1; | |
3097 | ||
3098 | logfp = fopen(git_path("logs/%s", refname), "r"); | |
3099 | if (!logfp) | |
3100 | return -1; | |
3101 | ||
3102 | /* Jump to the end */ | |
3103 | if (fseek(logfp, 0, SEEK_END) < 0) | |
3104 | return error("cannot seek back reflog for %s: %s", | |
3105 | refname, strerror(errno)); | |
3106 | pos = ftell(logfp); | |
3107 | while (!ret && 0 < pos) { | |
3108 | int cnt; | |
3109 | size_t nread; | |
3110 | char buf[BUFSIZ]; | |
3111 | char *endp, *scanp; | |
3112 | ||
3113 | /* Fill next block from the end */ | |
3114 | cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos; | |
3115 | if (fseek(logfp, pos - cnt, SEEK_SET)) | |
3116 | return error("cannot seek back reflog for %s: %s", | |
3117 | refname, strerror(errno)); | |
3118 | nread = fread(buf, cnt, 1, logfp); | |
3119 | if (nread != 1) | |
3120 | return error("cannot read %d bytes from reflog for %s: %s", | |
3121 | cnt, refname, strerror(errno)); | |
3122 | pos -= cnt; | |
3123 | ||
3124 | scanp = endp = buf + cnt; | |
3125 | if (at_tail && scanp[-1] == '\n') | |
3126 | /* Looking at the final LF at the end of the file */ | |
3127 | scanp--; | |
3128 | at_tail = 0; | |
3129 | ||
3130 | while (buf < scanp) { | |
3131 | /* | |
3132 | * terminating LF of the previous line, or the beginning | |
3133 | * of the buffer. | |
3134 | */ | |
3135 | char *bp; | |
3136 | ||
3137 | bp = find_beginning_of_line(buf, scanp); | |
3138 | ||
3139 | if (*bp == '\n') { | |
3140 | /* | |
3141 | * The newline is the end of the previous line, | |
3142 | * so we know we have complete line starting | |
3143 | * at (bp + 1). Prefix it onto any prior data | |
3144 | * we collected for the line and process it. | |
3145 | */ | |
3146 | strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1)); | |
3147 | scanp = bp; | |
3148 | endp = bp + 1; | |
3149 | ret = show_one_reflog_ent(&sb, fn, cb_data); | |
3150 | strbuf_reset(&sb); | |
3151 | if (ret) | |
3152 | break; | |
3153 | } else if (!pos) { | |
3154 | /* | |
3155 | * We are at the start of the buffer, and the | |
3156 | * start of the file; there is no previous | |
3157 | * line, and we have everything for this one. | |
3158 | * Process it, and we can end the loop. | |
3159 | */ | |
3160 | strbuf_splice(&sb, 0, 0, buf, endp - buf); | |
3161 | ret = show_one_reflog_ent(&sb, fn, cb_data); | |
3162 | strbuf_reset(&sb); | |
3163 | break; | |
3164 | } | |
3165 | ||
3166 | if (bp == buf) { | |
3167 | /* | |
3168 | * We are at the start of the buffer, and there | |
3169 | * is more file to read backwards. Which means | |
3170 | * we are in the middle of a line. Note that we | |
3171 | * may get here even if *bp was a newline; that | |
3172 | * just means we are at the exact end of the | |
3173 | * previous line, rather than some spot in the | |
3174 | * middle. | |
3175 | * | |
3176 | * Save away what we have to be combined with | |
3177 | * the data from the next read. | |
3178 | */ | |
3179 | strbuf_splice(&sb, 0, 0, buf, endp - buf); | |
3180 | break; | |
3181 | } | |
3182 | } | |
3183 | ||
3184 | } | |
3185 | if (!ret && sb.len) | |
3186 | die("BUG: reverse reflog parser had leftover data"); | |
3187 | ||
3188 | fclose(logfp); | |
3189 | strbuf_release(&sb); | |
3190 | return ret; | |
3191 | } | |
3192 | ||
3193 | int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data) | |
3194 | { | |
3195 | FILE *logfp; | |
3196 | struct strbuf sb = STRBUF_INIT; | |
3197 | int ret = 0; | |
3198 | ||
3199 | logfp = fopen(git_path("logs/%s", refname), "r"); | |
3200 | if (!logfp) | |
3201 | return -1; | |
3202 | ||
3203 | while (!ret && !strbuf_getwholeline(&sb, logfp, '\n')) | |
3204 | ret = show_one_reflog_ent(&sb, fn, cb_data); | |
3205 | fclose(logfp); | |
3206 | strbuf_release(&sb); | |
3207 | return ret; | |
3208 | } | |
3209 | /* | |
3210 | * Call fn for each reflog in the namespace indicated by name. name | |
3211 | * must be empty or end with '/'. Name will be used as a scratch | |
3212 | * space, but its contents will be restored before return. | |
3213 | */ | |
3214 | static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data) | |
3215 | { | |
3216 | DIR *d = opendir(git_path("logs/%s", name->buf)); | |
3217 | int retval = 0; | |
3218 | struct dirent *de; | |
3219 | int oldlen = name->len; | |
3220 | ||
3221 | if (!d) | |
3222 | return name->len ? errno : 0; | |
3223 | ||
3224 | while ((de = readdir(d)) != NULL) { | |
3225 | struct stat st; | |
3226 | ||
3227 | if (de->d_name[0] == '.') | |
3228 | continue; | |
3229 | if (ends_with(de->d_name, ".lock")) | |
3230 | continue; | |
3231 | strbuf_addstr(name, de->d_name); | |
3232 | if (stat(git_path("logs/%s", name->buf), &st) < 0) { | |
3233 | ; /* silently ignore */ | |
3234 | } else { | |
3235 | if (S_ISDIR(st.st_mode)) { | |
3236 | strbuf_addch(name, '/'); | |
3237 | retval = do_for_each_reflog(name, fn, cb_data); | |
3238 | } else { | |
3239 | struct object_id oid; | |
3240 | ||
3241 | if (read_ref_full(name->buf, 0, oid.hash, NULL)) | |
3242 | retval = error("bad ref for %s", name->buf); | |
3243 | else | |
3244 | retval = fn(name->buf, &oid, 0, cb_data); | |
3245 | } | |
3246 | if (retval) | |
3247 | break; | |
3248 | } | |
3249 | strbuf_setlen(name, oldlen); | |
3250 | } | |
3251 | closedir(d); | |
3252 | return retval; | |
3253 | } | |
3254 | ||
3255 | int for_each_reflog(each_ref_fn fn, void *cb_data) | |
3256 | { | |
3257 | int retval; | |
3258 | struct strbuf name; | |
3259 | strbuf_init(&name, PATH_MAX); | |
3260 | retval = do_for_each_reflog(&name, fn, cb_data); | |
3261 | strbuf_release(&name); | |
3262 | return retval; | |
3263 | } | |
3264 | ||
3265 | static int ref_update_reject_duplicates(struct string_list *refnames, | |
3266 | struct strbuf *err) | |
3267 | { | |
3268 | int i, n = refnames->nr; | |
3269 | ||
3270 | assert(err); | |
3271 | ||
3272 | for (i = 1; i < n; i++) | |
3273 | if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) { | |
3274 | strbuf_addf(err, | |
3275 | "multiple updates for ref '%s' not allowed.", | |
3276 | refnames->items[i].string); | |
3277 | return 1; | |
3278 | } | |
3279 | return 0; | |
3280 | } | |
3281 | ||
3282 | /* | |
3283 | * If update is a direct update of head_ref (the reference pointed to | |
3284 | * by HEAD), then add an extra REF_LOG_ONLY update for HEAD. | |
3285 | */ | |
3286 | static int split_head_update(struct ref_update *update, | |
3287 | struct ref_transaction *transaction, | |
3288 | const char *head_ref, | |
3289 | struct string_list *affected_refnames, | |
3290 | struct strbuf *err) | |
3291 | { | |
3292 | struct string_list_item *item; | |
3293 | struct ref_update *new_update; | |
3294 | ||
3295 | if ((update->flags & REF_LOG_ONLY) || | |
3296 | (update->flags & REF_ISPRUNING) || | |
3297 | (update->flags & REF_UPDATE_VIA_HEAD)) | |
3298 | return 0; | |
3299 | ||
3300 | if (strcmp(update->refname, head_ref)) | |
3301 | return 0; | |
3302 | ||
3303 | /* | |
3304 | * First make sure that HEAD is not already in the | |
3305 | * transaction. This insertion is O(N) in the transaction | |
3306 | * size, but it happens at most once per transaction. | |
3307 | */ | |
3308 | item = string_list_insert(affected_refnames, "HEAD"); | |
3309 | if (item->util) { | |
3310 | /* An entry already existed */ | |
3311 | strbuf_addf(err, | |
3312 | "multiple updates for 'HEAD' (including one " | |
3313 | "via its referent '%s') are not allowed", | |
3314 | update->refname); | |
3315 | return TRANSACTION_NAME_CONFLICT; | |
3316 | } | |
3317 | ||
3318 | new_update = ref_transaction_add_update( | |
3319 | transaction, "HEAD", | |
3320 | update->flags | REF_LOG_ONLY | REF_NODEREF, | |
3321 | update->new_sha1, update->old_sha1, | |
3322 | update->msg); | |
3323 | ||
3324 | item->util = new_update; | |
3325 | ||
3326 | return 0; | |
3327 | } | |
3328 | ||
3329 | /* | |
3330 | * update is for a symref that points at referent and doesn't have | |
3331 | * REF_NODEREF set. Split it into two updates: | |
3332 | * - The original update, but with REF_LOG_ONLY and REF_NODEREF set | |
3333 | * - A new, separate update for the referent reference | |
3334 | * Note that the new update will itself be subject to splitting when | |
3335 | * the iteration gets to it. | |
3336 | */ | |
3337 | static int split_symref_update(struct ref_update *update, | |
3338 | const char *referent, | |
3339 | struct ref_transaction *transaction, | |
3340 | struct string_list *affected_refnames, | |
3341 | struct strbuf *err) | |
3342 | { | |
3343 | struct string_list_item *item; | |
3344 | struct ref_update *new_update; | |
3345 | unsigned int new_flags; | |
3346 | ||
3347 | /* | |
3348 | * First make sure that referent is not already in the | |
3349 | * transaction. This insertion is O(N) in the transaction | |
3350 | * size, but it happens at most once per symref in a | |
3351 | * transaction. | |
3352 | */ | |
3353 | item = string_list_insert(affected_refnames, referent); | |
3354 | if (item->util) { | |
3355 | /* An entry already existed */ | |
3356 | strbuf_addf(err, | |
3357 | "multiple updates for '%s' (including one " | |
3358 | "via symref '%s') are not allowed", | |
3359 | referent, update->refname); | |
3360 | return TRANSACTION_NAME_CONFLICT; | |
3361 | } | |
3362 | ||
3363 | new_flags = update->flags; | |
3364 | if (!strcmp(update->refname, "HEAD")) { | |
3365 | /* | |
3366 | * Record that the new update came via HEAD, so that | |
3367 | * when we process it, split_head_update() doesn't try | |
3368 | * to add another reflog update for HEAD. Note that | |
3369 | * this bit will be propagated if the new_update | |
3370 | * itself needs to be split. | |
3371 | */ | |
3372 | new_flags |= REF_UPDATE_VIA_HEAD; | |
3373 | } | |
3374 | ||
3375 | new_update = ref_transaction_add_update( | |
3376 | transaction, referent, new_flags, | |
3377 | update->new_sha1, update->old_sha1, | |
3378 | update->msg); | |
3379 | ||
3380 | new_update->parent_update = update; | |
3381 | ||
3382 | /* | |
3383 | * Change the symbolic ref update to log only. Also, it | |
3384 | * doesn't need to check its old SHA-1 value, as that will be | |
3385 | * done when new_update is processed. | |
3386 | */ | |
3387 | update->flags |= REF_LOG_ONLY | REF_NODEREF; | |
3388 | update->flags &= ~REF_HAVE_OLD; | |
3389 | ||
3390 | item->util = new_update; | |
3391 | ||
3392 | return 0; | |
3393 | } | |
3394 | ||
3395 | /* | |
3396 | * Return the refname under which update was originally requested. | |
3397 | */ | |
3398 | static const char *original_update_refname(struct ref_update *update) | |
3399 | { | |
3400 | while (update->parent_update) | |
3401 | update = update->parent_update; | |
3402 | ||
3403 | return update->refname; | |
3404 | } | |
3405 | ||
3406 | /* | |
3407 | * Prepare for carrying out update: | |
3408 | * - Lock the reference referred to by update. | |
3409 | * - Read the reference under lock. | |
3410 | * - Check that its old SHA-1 value (if specified) is correct, and in | |
3411 | * any case record it in update->lock->old_oid for later use when | |
3412 | * writing the reflog. | |
3413 | * - If it is a symref update without REF_NODEREF, split it up into a | |
3414 | * REF_LOG_ONLY update of the symref and add a separate update for | |
3415 | * the referent to transaction. | |
3416 | * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY | |
3417 | * update of HEAD. | |
3418 | */ | |
3419 | static int lock_ref_for_update(struct ref_update *update, | |
3420 | struct ref_transaction *transaction, | |
3421 | const char *head_ref, | |
3422 | struct string_list *affected_refnames, | |
3423 | struct strbuf *err) | |
3424 | { | |
3425 | struct strbuf referent = STRBUF_INIT; | |
3426 | int mustexist = (update->flags & REF_HAVE_OLD) && | |
3427 | !is_null_sha1(update->old_sha1); | |
3428 | int ret; | |
3429 | struct ref_lock *lock; | |
3430 | ||
3431 | if ((update->flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1)) | |
3432 | update->flags |= REF_DELETING; | |
3433 | ||
3434 | if (head_ref) { | |
3435 | ret = split_head_update(update, transaction, head_ref, | |
3436 | affected_refnames, err); | |
3437 | if (ret) | |
3438 | return ret; | |
3439 | } | |
3440 | ||
3441 | ret = lock_raw_ref(update->refname, mustexist, | |
3442 | affected_refnames, NULL, | |
3443 | &update->lock, &referent, | |
3444 | &update->type, err); | |
3445 | ||
3446 | if (ret) { | |
3447 | char *reason; | |
3448 | ||
3449 | reason = strbuf_detach(err, NULL); | |
3450 | strbuf_addf(err, "cannot lock ref '%s': %s", | |
3451 | update->refname, reason); | |
3452 | free(reason); | |
3453 | return ret; | |
3454 | } | |
3455 | ||
3456 | lock = update->lock; | |
3457 | ||
3458 | if (update->type & REF_ISSYMREF) { | |
3459 | if (update->flags & REF_NODEREF) { | |
3460 | /* | |
3461 | * We won't be reading the referent as part of | |
3462 | * the transaction, so we have to read it here | |
3463 | * to record and possibly check old_sha1: | |
3464 | */ | |
3465 | if (read_ref_full(update->refname, | |
3466 | mustexist ? RESOLVE_REF_READING : 0, | |
3467 | lock->old_oid.hash, NULL)) { | |
3468 | if (update->flags & REF_HAVE_OLD) { | |
3469 | strbuf_addf(err, "cannot lock ref '%s': " | |
3470 | "can't resolve old value", | |
3471 | update->refname); | |
3472 | return TRANSACTION_GENERIC_ERROR; | |
3473 | } else { | |
3474 | hashclr(lock->old_oid.hash); | |
3475 | } | |
3476 | } | |
3477 | if ((update->flags & REF_HAVE_OLD) && | |
3478 | hashcmp(lock->old_oid.hash, update->old_sha1)) { | |
3479 | strbuf_addf(err, "cannot lock ref '%s': " | |
3480 | "is at %s but expected %s", | |
3481 | update->refname, | |
3482 | sha1_to_hex(lock->old_oid.hash), | |
3483 | sha1_to_hex(update->old_sha1)); | |
3484 | return TRANSACTION_GENERIC_ERROR; | |
3485 | } | |
3486 | ||
3487 | } else { | |
3488 | /* | |
3489 | * Create a new update for the reference this | |
3490 | * symref is pointing at. Also, we will record | |
3491 | * and verify old_sha1 for this update as part | |
3492 | * of processing the split-off update, so we | |
3493 | * don't have to do it here. | |
3494 | */ | |
3495 | ret = split_symref_update(update, referent.buf, transaction, | |
3496 | affected_refnames, err); | |
3497 | if (ret) | |
3498 | return ret; | |
3499 | } | |
3500 | } else { | |
3501 | struct ref_update *parent_update; | |
3502 | ||
3503 | /* | |
3504 | * If this update is happening indirectly because of a | |
3505 | * symref update, record the old SHA-1 in the parent | |
3506 | * update: | |
3507 | */ | |
3508 | for (parent_update = update->parent_update; | |
3509 | parent_update; | |
3510 | parent_update = parent_update->parent_update) { | |
3511 | oidcpy(&parent_update->lock->old_oid, &lock->old_oid); | |
3512 | } | |
3513 | ||
3514 | if ((update->flags & REF_HAVE_OLD) && | |
3515 | hashcmp(lock->old_oid.hash, update->old_sha1)) { | |
3516 | if (is_null_sha1(update->old_sha1)) | |
3517 | strbuf_addf(err, "cannot lock ref '%s': reference already exists", | |
3518 | original_update_refname(update)); | |
3519 | else | |
3520 | strbuf_addf(err, "cannot lock ref '%s': is at %s but expected %s", | |
3521 | original_update_refname(update), | |
3522 | sha1_to_hex(lock->old_oid.hash), | |
3523 | sha1_to_hex(update->old_sha1)); | |
3524 | ||
3525 | return TRANSACTION_GENERIC_ERROR; | |
3526 | } | |
3527 | } | |
3528 | ||
3529 | if ((update->flags & REF_HAVE_NEW) && | |
3530 | !(update->flags & REF_DELETING) && | |
3531 | !(update->flags & REF_LOG_ONLY)) { | |
3532 | if (!(update->type & REF_ISSYMREF) && | |
3533 | !hashcmp(lock->old_oid.hash, update->new_sha1)) { | |
3534 | /* | |
3535 | * The reference already has the desired | |
3536 | * value, so we don't need to write it. | |
3537 | */ | |
3538 | } else if (write_ref_to_lockfile(lock, update->new_sha1, | |
3539 | err)) { | |
3540 | char *write_err = strbuf_detach(err, NULL); | |
3541 | ||
3542 | /* | |
3543 | * The lock was freed upon failure of | |
3544 | * write_ref_to_lockfile(): | |
3545 | */ | |
3546 | update->lock = NULL; | |
3547 | strbuf_addf(err, | |
3548 | "cannot update the ref '%s': %s", | |
3549 | update->refname, write_err); | |
3550 | free(write_err); | |
3551 | return TRANSACTION_GENERIC_ERROR; | |
3552 | } else { | |
3553 | update->flags |= REF_NEEDS_COMMIT; | |
3554 | } | |
3555 | } | |
3556 | if (!(update->flags & REF_NEEDS_COMMIT)) { | |
3557 | /* | |
3558 | * We didn't call write_ref_to_lockfile(), so | |
3559 | * the lockfile is still open. Close it to | |
3560 | * free up the file descriptor: | |
3561 | */ | |
3562 | if (close_ref(lock)) { | |
3563 | strbuf_addf(err, "couldn't close '%s.lock'", | |
3564 | update->refname); | |
3565 | return TRANSACTION_GENERIC_ERROR; | |
3566 | } | |
3567 | } | |
3568 | return 0; | |
3569 | } | |
3570 | ||
3571 | int ref_transaction_commit(struct ref_transaction *transaction, | |
3572 | struct strbuf *err) | |
3573 | { | |
3574 | int ret = 0, i; | |
3575 | struct string_list refs_to_delete = STRING_LIST_INIT_NODUP; | |
3576 | struct string_list_item *ref_to_delete; | |
3577 | struct string_list affected_refnames = STRING_LIST_INIT_NODUP; | |
3578 | char *head_ref = NULL; | |
3579 | int head_type; | |
3580 | struct object_id head_oid; | |
3581 | ||
3582 | assert(err); | |
3583 | ||
3584 | if (transaction->state != REF_TRANSACTION_OPEN) | |
3585 | die("BUG: commit called for transaction that is not open"); | |
3586 | ||
3587 | if (!transaction->nr) { | |
3588 | transaction->state = REF_TRANSACTION_CLOSED; | |
3589 | return 0; | |
3590 | } | |
3591 | ||
3592 | /* | |
3593 | * Fail if a refname appears more than once in the | |
3594 | * transaction. (If we end up splitting up any updates using | |
3595 | * split_symref_update() or split_head_update(), those | |
3596 | * functions will check that the new updates don't have the | |
3597 | * same refname as any existing ones.) | |
3598 | */ | |
3599 | for (i = 0; i < transaction->nr; i++) { | |
3600 | struct ref_update *update = transaction->updates[i]; | |
3601 | struct string_list_item *item = | |
3602 | string_list_append(&affected_refnames, update->refname); | |
3603 | ||
3604 | /* | |
3605 | * We store a pointer to update in item->util, but at | |
3606 | * the moment we never use the value of this field | |
3607 | * except to check whether it is non-NULL. | |
3608 | */ | |
3609 | item->util = update; | |
3610 | } | |
3611 | string_list_sort(&affected_refnames); | |
3612 | if (ref_update_reject_duplicates(&affected_refnames, err)) { | |
3613 | ret = TRANSACTION_GENERIC_ERROR; | |
3614 | goto cleanup; | |
3615 | } | |
3616 | ||
3617 | /* | |
3618 | * Special hack: If a branch is updated directly and HEAD | |
3619 | * points to it (may happen on the remote side of a push | |
3620 | * for example) then logically the HEAD reflog should be | |
3621 | * updated too. | |
3622 | * | |
3623 | * A generic solution would require reverse symref lookups, | |
3624 | * but finding all symrefs pointing to a given branch would be | |
3625 | * rather costly for this rare event (the direct update of a | |
3626 | * branch) to be worth it. So let's cheat and check with HEAD | |
3627 | * only, which should cover 99% of all usage scenarios (even | |
3628 | * 100% of the default ones). | |
3629 | * | |
3630 | * So if HEAD is a symbolic reference, then record the name of | |
3631 | * the reference that it points to. If we see an update of | |
3632 | * head_ref within the transaction, then split_head_update() | |
3633 | * arranges for the reflog of HEAD to be updated, too. | |
3634 | */ | |
3635 | head_ref = resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE, | |
3636 | head_oid.hash, &head_type); | |
3637 | ||
3638 | if (head_ref && !(head_type & REF_ISSYMREF)) { | |
3639 | free(head_ref); | |
3640 | head_ref = NULL; | |
3641 | } | |
3642 | ||
3643 | /* | |
3644 | * Acquire all locks, verify old values if provided, check | |
3645 | * that new values are valid, and write new values to the | |
3646 | * lockfiles, ready to be activated. Only keep one lockfile | |
3647 | * open at a time to avoid running out of file descriptors. | |
3648 | */ | |
3649 | for (i = 0; i < transaction->nr; i++) { | |
3650 | struct ref_update *update = transaction->updates[i]; | |
3651 | ||
3652 | ret = lock_ref_for_update(update, transaction, head_ref, | |
3653 | &affected_refnames, err); | |
3654 | if (ret) | |
3655 | goto cleanup; | |
3656 | } | |
3657 | ||
3658 | /* Perform updates first so live commits remain referenced */ | |
3659 | for (i = 0; i < transaction->nr; i++) { | |
3660 | struct ref_update *update = transaction->updates[i]; | |
3661 | struct ref_lock *lock = update->lock; | |
3662 | ||
3663 | if (update->flags & REF_NEEDS_COMMIT || | |
3664 | update->flags & REF_LOG_ONLY) { | |
3665 | if (log_ref_write(lock->ref_name, lock->old_oid.hash, | |
3666 | update->new_sha1, | |
3667 | update->msg, update->flags, err)) { | |
3668 | char *old_msg = strbuf_detach(err, NULL); | |
3669 | ||
3670 | strbuf_addf(err, "cannot update the ref '%s': %s", | |
3671 | lock->ref_name, old_msg); | |
3672 | free(old_msg); | |
3673 | unlock_ref(lock); | |
3674 | update->lock = NULL; | |
3675 | ret = TRANSACTION_GENERIC_ERROR; | |
3676 | goto cleanup; | |
3677 | } | |
3678 | } | |
3679 | if (update->flags & REF_NEEDS_COMMIT) { | |
3680 | clear_loose_ref_cache(&ref_cache); | |
3681 | if (commit_ref(lock)) { | |
3682 | strbuf_addf(err, "couldn't set '%s'", lock->ref_name); | |
3683 | unlock_ref(lock); | |
3684 | update->lock = NULL; | |
3685 | ret = TRANSACTION_GENERIC_ERROR; | |
3686 | goto cleanup; | |
3687 | } | |
3688 | } | |
3689 | } | |
3690 | /* Perform deletes now that updates are safely completed */ | |
3691 | for (i = 0; i < transaction->nr; i++) { | |
3692 | struct ref_update *update = transaction->updates[i]; | |
3693 | ||
3694 | if (update->flags & REF_DELETING && | |
3695 | !(update->flags & REF_LOG_ONLY)) { | |
3696 | if (delete_ref_loose(update->lock, update->type, err)) { | |
3697 | ret = TRANSACTION_GENERIC_ERROR; | |
3698 | goto cleanup; | |
3699 | } | |
3700 | ||
3701 | if (!(update->flags & REF_ISPRUNING)) | |
3702 | string_list_append(&refs_to_delete, | |
3703 | update->lock->ref_name); | |
3704 | } | |
3705 | } | |
3706 | ||
3707 | if (repack_without_refs(&refs_to_delete, err)) { | |
3708 | ret = TRANSACTION_GENERIC_ERROR; | |
3709 | goto cleanup; | |
3710 | } | |
3711 | for_each_string_list_item(ref_to_delete, &refs_to_delete) | |
3712 | unlink_or_warn(git_path("logs/%s", ref_to_delete->string)); | |
3713 | clear_loose_ref_cache(&ref_cache); | |
3714 | ||
3715 | cleanup: | |
3716 | transaction->state = REF_TRANSACTION_CLOSED; | |
3717 | ||
3718 | for (i = 0; i < transaction->nr; i++) | |
3719 | if (transaction->updates[i]->lock) | |
3720 | unlock_ref(transaction->updates[i]->lock); | |
3721 | string_list_clear(&refs_to_delete, 0); | |
3722 | free(head_ref); | |
3723 | string_list_clear(&affected_refnames, 0); | |
3724 | ||
3725 | return ret; | |
3726 | } | |
3727 | ||
3728 | static int ref_present(const char *refname, | |
3729 | const struct object_id *oid, int flags, void *cb_data) | |
3730 | { | |
3731 | struct string_list *affected_refnames = cb_data; | |
3732 | ||
3733 | return string_list_has_string(affected_refnames, refname); | |
3734 | } | |
3735 | ||
3736 | int initial_ref_transaction_commit(struct ref_transaction *transaction, | |
3737 | struct strbuf *err) | |
3738 | { | |
3739 | int ret = 0, i; | |
3740 | struct string_list affected_refnames = STRING_LIST_INIT_NODUP; | |
3741 | ||
3742 | assert(err); | |
3743 | ||
3744 | if (transaction->state != REF_TRANSACTION_OPEN) | |
3745 | die("BUG: commit called for transaction that is not open"); | |
3746 | ||
3747 | /* Fail if a refname appears more than once in the transaction: */ | |
3748 | for (i = 0; i < transaction->nr; i++) | |
3749 | string_list_append(&affected_refnames, | |
3750 | transaction->updates[i]->refname); | |
3751 | string_list_sort(&affected_refnames); | |
3752 | if (ref_update_reject_duplicates(&affected_refnames, err)) { | |
3753 | ret = TRANSACTION_GENERIC_ERROR; | |
3754 | goto cleanup; | |
3755 | } | |
3756 | ||
3757 | /* | |
3758 | * It's really undefined to call this function in an active | |
3759 | * repository or when there are existing references: we are | |
3760 | * only locking and changing packed-refs, so (1) any | |
3761 | * simultaneous processes might try to change a reference at | |
3762 | * the same time we do, and (2) any existing loose versions of | |
3763 | * the references that we are setting would have precedence | |
3764 | * over our values. But some remote helpers create the remote | |
3765 | * "HEAD" and "master" branches before calling this function, | |
3766 | * so here we really only check that none of the references | |
3767 | * that we are creating already exists. | |
3768 | */ | |
3769 | if (for_each_rawref(ref_present, &affected_refnames)) | |
3770 | die("BUG: initial ref transaction called with existing refs"); | |
3771 | ||
3772 | for (i = 0; i < transaction->nr; i++) { | |
3773 | struct ref_update *update = transaction->updates[i]; | |
3774 | ||
3775 | if ((update->flags & REF_HAVE_OLD) && | |
3776 | !is_null_sha1(update->old_sha1)) | |
3777 | die("BUG: initial ref transaction with old_sha1 set"); | |
3778 | if (verify_refname_available(update->refname, | |
3779 | &affected_refnames, NULL, | |
3780 | err)) { | |
3781 | ret = TRANSACTION_NAME_CONFLICT; | |
3782 | goto cleanup; | |
3783 | } | |
3784 | } | |
3785 | ||
3786 | if (lock_packed_refs(0)) { | |
3787 | strbuf_addf(err, "unable to lock packed-refs file: %s", | |
3788 | strerror(errno)); | |
3789 | ret = TRANSACTION_GENERIC_ERROR; | |
3790 | goto cleanup; | |
3791 | } | |
3792 | ||
3793 | for (i = 0; i < transaction->nr; i++) { | |
3794 | struct ref_update *update = transaction->updates[i]; | |
3795 | ||
3796 | if ((update->flags & REF_HAVE_NEW) && | |
3797 | !is_null_sha1(update->new_sha1)) | |
3798 | add_packed_ref(update->refname, update->new_sha1); | |
3799 | } | |
3800 | ||
3801 | if (commit_packed_refs()) { | |
3802 | strbuf_addf(err, "unable to commit packed-refs file: %s", | |
3803 | strerror(errno)); | |
3804 | ret = TRANSACTION_GENERIC_ERROR; | |
3805 | goto cleanup; | |
3806 | } | |
3807 | ||
3808 | cleanup: | |
3809 | transaction->state = REF_TRANSACTION_CLOSED; | |
3810 | string_list_clear(&affected_refnames, 0); | |
3811 | return ret; | |
3812 | } | |
3813 | ||
3814 | struct expire_reflog_cb { | |
3815 | unsigned int flags; | |
3816 | reflog_expiry_should_prune_fn *should_prune_fn; | |
3817 | void *policy_cb; | |
3818 | FILE *newlog; | |
3819 | unsigned char last_kept_sha1[20]; | |
3820 | }; | |
3821 | ||
3822 | static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1, | |
3823 | const char *email, unsigned long timestamp, int tz, | |
3824 | const char *message, void *cb_data) | |
3825 | { | |
3826 | struct expire_reflog_cb *cb = cb_data; | |
3827 | struct expire_reflog_policy_cb *policy_cb = cb->policy_cb; | |
3828 | ||
3829 | if (cb->flags & EXPIRE_REFLOGS_REWRITE) | |
3830 | osha1 = cb->last_kept_sha1; | |
3831 | ||
3832 | if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz, | |
3833 | message, policy_cb)) { | |
3834 | if (!cb->newlog) | |
3835 | printf("would prune %s", message); | |
3836 | else if (cb->flags & EXPIRE_REFLOGS_VERBOSE) | |
3837 | printf("prune %s", message); | |
3838 | } else { | |
3839 | if (cb->newlog) { | |
3840 | fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s", | |
3841 | sha1_to_hex(osha1), sha1_to_hex(nsha1), | |
3842 | email, timestamp, tz, message); | |
3843 | hashcpy(cb->last_kept_sha1, nsha1); | |
3844 | } | |
3845 | if (cb->flags & EXPIRE_REFLOGS_VERBOSE) | |
3846 | printf("keep %s", message); | |
3847 | } | |
3848 | return 0; | |
3849 | } | |
3850 | ||
3851 | int reflog_expire(const char *refname, const unsigned char *sha1, | |
3852 | unsigned int flags, | |
3853 | reflog_expiry_prepare_fn prepare_fn, | |
3854 | reflog_expiry_should_prune_fn should_prune_fn, | |
3855 | reflog_expiry_cleanup_fn cleanup_fn, | |
3856 | void *policy_cb_data) | |
3857 | { | |
3858 | static struct lock_file reflog_lock; | |
3859 | struct expire_reflog_cb cb; | |
3860 | struct ref_lock *lock; | |
3861 | char *log_file; | |
3862 | int status = 0; | |
3863 | int type; | |
3864 | struct strbuf err = STRBUF_INIT; | |
3865 | ||
3866 | memset(&cb, 0, sizeof(cb)); | |
3867 | cb.flags = flags; | |
3868 | cb.policy_cb = policy_cb_data; | |
3869 | cb.should_prune_fn = should_prune_fn; | |
3870 | ||
3871 | /* | |
3872 | * The reflog file is locked by holding the lock on the | |
3873 | * reference itself, plus we might need to update the | |
3874 | * reference if --updateref was specified: | |
3875 | */ | |
3876 | lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, REF_NODEREF, | |
3877 | &type, &err); | |
3878 | if (!lock) { | |
3879 | error("cannot lock ref '%s': %s", refname, err.buf); | |
3880 | strbuf_release(&err); | |
3881 | return -1; | |
3882 | } | |
3883 | if (!reflog_exists(refname)) { | |
3884 | unlock_ref(lock); | |
3885 | return 0; | |
3886 | } | |
3887 | ||
3888 | log_file = git_pathdup("logs/%s", refname); | |
3889 | if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) { | |
3890 | /* | |
3891 | * Even though holding $GIT_DIR/logs/$reflog.lock has | |
3892 | * no locking implications, we use the lock_file | |
3893 | * machinery here anyway because it does a lot of the | |
3894 | * work we need, including cleaning up if the program | |
3895 | * exits unexpectedly. | |
3896 | */ | |
3897 | if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) { | |
3898 | struct strbuf err = STRBUF_INIT; | |
3899 | unable_to_lock_message(log_file, errno, &err); | |
3900 | error("%s", err.buf); | |
3901 | strbuf_release(&err); | |
3902 | goto failure; | |
3903 | } | |
3904 | cb.newlog = fdopen_lock_file(&reflog_lock, "w"); | |
3905 | if (!cb.newlog) { | |
3906 | error("cannot fdopen %s (%s)", | |
3907 | get_lock_file_path(&reflog_lock), strerror(errno)); | |
3908 | goto failure; | |
3909 | } | |
3910 | } | |
3911 | ||
3912 | (*prepare_fn)(refname, sha1, cb.policy_cb); | |
3913 | for_each_reflog_ent(refname, expire_reflog_ent, &cb); | |
3914 | (*cleanup_fn)(cb.policy_cb); | |
3915 | ||
3916 | if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) { | |
3917 | /* | |
3918 | * It doesn't make sense to adjust a reference pointed | |
3919 | * to by a symbolic ref based on expiring entries in | |
3920 | * the symbolic reference's reflog. Nor can we update | |
3921 | * a reference if there are no remaining reflog | |
3922 | * entries. | |
3923 | */ | |
3924 | int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) && | |
3925 | !(type & REF_ISSYMREF) && | |
3926 | !is_null_sha1(cb.last_kept_sha1); | |
3927 | ||
3928 | if (close_lock_file(&reflog_lock)) { | |
3929 | status |= error("couldn't write %s: %s", log_file, | |
3930 | strerror(errno)); | |
3931 | } else if (update && | |
3932 | (write_in_full(get_lock_file_fd(lock->lk), | |
3933 | sha1_to_hex(cb.last_kept_sha1), 40) != 40 || | |
3934 | write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 || | |
3935 | close_ref(lock) < 0)) { | |
3936 | status |= error("couldn't write %s", | |
3937 | get_lock_file_path(lock->lk)); | |
3938 | rollback_lock_file(&reflog_lock); | |
3939 | } else if (commit_lock_file(&reflog_lock)) { | |
3940 | status |= error("unable to write reflog '%s' (%s)", | |
3941 | log_file, strerror(errno)); | |
3942 | } else if (update && commit_ref(lock)) { | |
3943 | status |= error("couldn't set %s", lock->ref_name); | |
3944 | } | |
3945 | } | |
3946 | free(log_file); | |
3947 | unlock_ref(lock); | |
3948 | return status; | |
3949 | ||
3950 | failure: | |
3951 | rollback_lock_file(&reflog_lock); | |
3952 | free(log_file); | |
3953 | unlock_ref(lock); | |
3954 | return -1; | |
3955 | } |