diff options
Diffstat (limited to 'refs.c')
| -rw-r--r-- | refs.c | 849 |
1 files changed, 581 insertions, 268 deletions
@@ -6,6 +6,14 @@ #include "dir.h" #include "string-list.h" +struct ref_lock { + char *ref_name; + char *orig_ref_name; + struct lock_file *lk; + unsigned char old_sha1[20]; + int lock_fd; +}; + /* * How to handle various characters in refnames: * 0: An acceptable character for refs @@ -26,10 +34,35 @@ static unsigned char refname_disposition[256] = { }; /* - * Used as a flag to ref_transaction_delete when a loose ref is being + * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken + * refs (i.e., because the reference is about to be deleted anyway). + */ +#define REF_DELETING 0x02 + +/* + * Used as a flag in ref_update::flags when a loose ref is being * pruned. */ -#define REF_ISPRUNING 0x0100 +#define REF_ISPRUNING 0x04 + +/* + * Used as a flag in ref_update::flags when the reference should be + * updated to new_sha1. + */ +#define REF_HAVE_NEW 0x08 + +/* + * Used as a flag in ref_update::flags when old_sha1 should be + * checked. + */ +#define REF_HAVE_OLD 0x10 + +/* + * Used as a flag in ref_update::flags when the lockfile needs to be + * committed. + */ +#define REF_NEEDS_COMMIT 0x20 + /* * Try to read one refname component from the front of refname. * Return the length of the component found, or -1 if the component is @@ -236,7 +269,7 @@ struct ref_dir { * presence of an empty subdirectory does not block the creation of a * similarly-named reference. (The fact that reference names with the * same leading components can conflict *with each other* is a - * separate issue that is regulated by is_refname_available().) + * separate issue that is regulated by verify_refname_available().) * * Please note that the name field contains the fully-qualified * reference (or subdirectory) name. Space could be saved by only @@ -814,121 +847,181 @@ static void prime_ref_dir(struct ref_dir *dir) } } -static int entry_matches(struct ref_entry *entry, const struct string_list *list) -{ - return list && string_list_has_string(list, entry->name); -} - struct nonmatching_ref_data { const struct string_list *skip; - struct ref_entry *found; + const char *conflicting_refname; }; static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) { struct nonmatching_ref_data *data = vdata; - if (entry_matches(entry, data->skip)) + if (data->skip && string_list_has_string(data->skip, entry->name)) return 0; - data->found = entry; + data->conflicting_refname = entry->name; return 1; } -static void report_refname_conflict(struct ref_entry *entry, - const char *refname) -{ - error("'%s' exists; cannot create '%s'", entry->name, refname); -} - /* - * Return true iff a reference named refname could be created without - * conflicting with the name of an existing reference in dir. If - * skip is non-NULL, ignore potential conflicts with refs in skip - * (e.g., because they are scheduled for deletion in the same - * operation). + * Return 0 if a reference named refname could be created without + * conflicting with the name of an existing reference in dir. + * Otherwise, return a negative value and write an explanation to err. + * If extras is non-NULL, it is a list of additional refnames with + * which refname is not allowed to conflict. If skip is non-NULL, + * ignore potential conflicts with refs in skip (e.g., because they + * are scheduled for deletion in the same operation). Behavior is + * undefined if the same name is listed in both extras and skip. * * Two reference names conflict if one of them exactly matches the - * leading components of the other; e.g., "foo/bar" conflicts with - * both "foo" and with "foo/bar/baz" but not with "foo/bar" or - * "foo/barbados". + * leading components of the other; e.g., "refs/foo/bar" conflicts + * with both "refs/foo" and with "refs/foo/bar/baz" but not with + * "refs/foo/bar" or "refs/foo/barbados". * - * skip must be sorted. + * extras and skip must be sorted. */ -static int is_refname_available(const char *refname, - const struct string_list *skip, - struct ref_dir *dir) +static int verify_refname_available(const char *refname, + const struct string_list *extras, + const struct string_list *skip, + struct ref_dir *dir, + struct strbuf *err) { const char *slash; - size_t len; int pos; - char *dirname; + struct strbuf dirname = STRBUF_INIT; + int ret = -1; + + /* + * For the sake of comments in this function, suppose that + * refname is "refs/foo/bar". + */ + + assert(err); + strbuf_grow(&dirname, strlen(refname) + 1); for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { + /* Expand dirname to the new prefix, not including the trailing slash: */ + strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); + /* - * We are still at a leading dir of the refname; we are - * looking for a conflict with a leaf entry. - * - * If we find one, we still must make sure it is - * not in "skip". + * We are still at a leading dir of the refname (e.g., + * "refs/foo"; if there is a reference with that name, + * it is a conflict, *unless* it is in skip. */ - pos = search_ref_dir(dir, refname, slash - refname); - if (pos >= 0) { - struct ref_entry *entry = dir->entries[pos]; - if (entry_matches(entry, skip)) - return 1; - report_refname_conflict(entry, refname); - return 0; + if (dir) { + pos = search_ref_dir(dir, dirname.buf, dirname.len); + if (pos >= 0 && + (!skip || !string_list_has_string(skip, dirname.buf))) { + /* + * We found a reference whose name is + * a proper prefix of refname; e.g., + * "refs/foo", and is not in skip. + */ + strbuf_addf(err, "'%s' exists; cannot create '%s'", + dirname.buf, refname); + goto cleanup; + } } + if (extras && string_list_has_string(extras, dirname.buf) && + (!skip || !string_list_has_string(skip, dirname.buf))) { + strbuf_addf(err, "cannot process '%s' and '%s' at the same time", + refname, dirname.buf); + goto cleanup; + } /* * Otherwise, we can try to continue our search with - * the next component; if we come up empty, we know - * there is nothing under this whole prefix. + * the next component. So try to look up the + * directory, e.g., "refs/foo/". If we come up empty, + * we know there is nothing under this whole prefix, + * but even in that case we still have to continue the + * search for conflicts with extras. */ - pos = search_ref_dir(dir, refname, slash + 1 - refname); - if (pos < 0) - return 1; - - dir = get_ref_dir(dir->entries[pos]); + strbuf_addch(&dirname, '/'); + if (dir) { + pos = search_ref_dir(dir, dirname.buf, dirname.len); + if (pos < 0) { + /* + * There was no directory "refs/foo/", + * so there is nothing under this + * whole prefix. So there is no need + * to continue looking for conflicting + * references. But we need to continue + * looking for conflicting extras. + */ + dir = NULL; + } else { + dir = get_ref_dir(dir->entries[pos]); + } + } } /* - * We are at the leaf of our refname; we want to - * make sure there are no directories which match it. + * We are at the leaf of our refname (e.g., "refs/foo/bar"). + * There is no point in searching for a reference with that + * name, because a refname isn't considered to conflict with + * itself. But we still need to check for references whose + * names are in the "refs/foo/bar/" namespace, because they + * *do* conflict. */ - len = strlen(refname); - dirname = xmallocz(len + 1); - sprintf(dirname, "%s/", refname); - pos = search_ref_dir(dir, dirname, len + 1); - free(dirname); + strbuf_addstr(&dirname, refname + dirname.len); + strbuf_addch(&dirname, '/'); + + if (dir) { + pos = search_ref_dir(dir, dirname.buf, dirname.len); + + if (pos >= 0) { + /* + * We found a directory named "$refname/" + * (e.g., "refs/foo/bar/"). It is a problem + * iff it contains any ref that is not in + * "skip". + */ + struct nonmatching_ref_data data; + + data.skip = skip; + data.conflicting_refname = NULL; + dir = get_ref_dir(dir->entries[pos]); + sort_ref_dir(dir); + if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) { + strbuf_addf(err, "'%s' exists; cannot create '%s'", + data.conflicting_refname, refname); + goto cleanup; + } + } + } - if (pos >= 0) { + if (extras) { /* - * We found a directory named "refname". It is a - * problem iff it contains any ref that is not - * in "skip". + * Check for entries in extras that start with + * "$refname/". We do that by looking for the place + * where "$refname/" would be inserted in extras. If + * there is an entry at that position that starts with + * "$refname/" and is not in skip, then we have a + * conflict. */ - struct ref_entry *entry = dir->entries[pos]; - struct ref_dir *dir = get_ref_dir(entry); - struct nonmatching_ref_data data; + for (pos = string_list_find_insert_index(extras, dirname.buf, 0); + pos < extras->nr; pos++) { + const char *extra_refname = extras->items[pos].string; - data.skip = skip; - sort_ref_dir(dir); - if (!do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) - return 1; + if (!starts_with(extra_refname, dirname.buf)) + break; - report_refname_conflict(data.found, refname); - return 0; + if (!skip || !string_list_has_string(skip, extra_refname)) { + strbuf_addf(err, "cannot process '%s' and '%s' at the same time", + refname, extra_refname); + goto cleanup; + } + } } - /* - * There is no point in searching for another leaf - * node which matches it; such an entry would be the - * ref we are looking for, not a conflict. - */ - return 1; + /* No conflicts were found */ + ret = 0; + +cleanup: + strbuf_release(&dirname); + return ret; } struct packed_ref_cache { @@ -1281,19 +1374,34 @@ static void read_loose_refs(const char *dirname, struct ref_dir *dir) create_dir_entry(refs, refname.buf, refname.len, 1)); } else { + int read_ok; + if (*refs->name) { hashclr(sha1); flag = 0; - if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) { - hashclr(sha1); - flag |= REF_ISBROKEN; - } - } else if (read_ref_full(refname.buf, - RESOLVE_REF_READING, - sha1, &flag)) { + read_ok = !resolve_gitlink_ref(refs->name, + refname.buf, sha1); + } else { + read_ok = !read_ref_full(refname.buf, + RESOLVE_REF_READING, + sha1, &flag); + } + + if (!read_ok) { hashclr(sha1); flag |= REF_ISBROKEN; + } else if (is_null_sha1(sha1)) { + /* + * It is so astronomically unlikely + * that NULL_SHA1 is the SHA-1 of an + * actual object that we consider its + * appearance in a loose reference + * file to be repo corruption + * (probably due to a software bug). + */ + flag |= REF_ISBROKEN; } + if (check_refname_format(refname.buf, REFNAME_ALLOW_ONELEVEL)) { hashclr(sha1); @@ -2098,6 +2206,16 @@ int refname_match(const char *abbrev_name, const char *full_name) return 0; } +static void unlock_ref(struct ref_lock *lock) +{ + /* Do not free lock->lk -- atexit() still looks at them */ + if (lock->lk) + rollback_lock_file(lock->lk); + free(lock->ref_name); + free(lock->orig_ref_name); + free(lock); +} + /* This function should make sure errno is meaningful on error */ static struct ref_lock *verify_lock(struct ref_lock *lock, const unsigned char *old_sha1, int mustexist) @@ -2234,8 +2352,10 @@ int dwim_log(const char *str, int len, unsigned char *sha1, char **log) */ static struct ref_lock *lock_ref_sha1_basic(const char *refname, const unsigned char *old_sha1, + const struct string_list *extras, const struct string_list *skip, - int flags, int *type_p) + unsigned int flags, int *type_p, + struct strbuf *err) { char *ref_file; const char *orig_refname = refname; @@ -2244,9 +2364,10 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, int type, lflags; int mustexist = (old_sha1 && !is_null_sha1(old_sha1)); int resolve_flags = 0; - int missing = 0; int attempts_remaining = 3; + assert(err); + lock = xcalloc(1, sizeof(struct ref_lock)); lock->lock_fd = -1; @@ -2269,7 +2390,12 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, ref_file = git_path("%s", orig_refname); if (remove_empty_directories(ref_file)) { last_errno = errno; - error("there are still refs under '%s'", orig_refname); + + if (!verify_refname_available(orig_refname, extras, skip, + get_loose_refs(&ref_cache), err)) + strbuf_addf(err, "there are still refs under '%s'", + orig_refname); + goto error_return; } refname = resolve_ref_unsafe(orig_refname, resolve_flags, @@ -2279,18 +2405,23 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, *type_p = type; if (!refname) { last_errno = errno; - error("unable to resolve reference %s: %s", - orig_refname, strerror(errno)); + if (last_errno != ENOTDIR || + !verify_refname_available(orig_refname, extras, skip, + get_loose_refs(&ref_cache), err)) + strbuf_addf(err, "unable to resolve reference %s: %s", + orig_refname, strerror(last_errno)); + goto error_return; } - missing = is_null_sha1(lock->old_sha1); - /* When the ref did not exist and we are creating it, - * make sure there is no existing ref that is packed - * whose name begins with our refname, nor a ref whose - * name is a proper prefix of our refname. + /* + * If the ref did not exist and we are creating it, make sure + * there is no existing packed ref whose name begins with our + * refname, nor a packed ref whose name is a proper prefix of + * our refname. */ - if (missing && - !is_refname_available(refname, skip, get_packed_refs(&ref_cache))) { + if (is_null_sha1(lock->old_sha1) && + verify_refname_available(refname, extras, skip, + get_packed_refs(&ref_cache), err)) { last_errno = ENOTDIR; goto error_return; } @@ -2305,10 +2436,6 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, lock->ref_name = xstrdup(refname); lock->orig_ref_name = xstrdup(orig_refname); ref_file = git_path("%s", refname); - if (missing) - lock->force_write = 1; - if ((flags & REF_NODEREF) && (type & REF_ISSYMREF)) - lock->force_write = 1; retry: switch (safe_create_leading_directories(ref_file)) { @@ -2320,7 +2447,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, /* fall through */ default: last_errno = errno; - error("unable to create directory for %s", ref_file); + strbuf_addf(err, "unable to create directory for %s", ref_file); goto error_return; } @@ -2335,10 +2462,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, */ goto retry; else { - struct strbuf err = STRBUF_INIT; - unable_to_lock_message(ref_file, errno, &err); - error("%s", err.buf); - strbuf_release(&err); + unable_to_lock_message(ref_file, errno, err); goto error_return; } } @@ -2350,13 +2474,6 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, return NULL; } -struct ref_lock *lock_any_ref_for_update(const char *refname, - const unsigned char *old_sha1, - int flags, int *type_p) -{ - return lock_ref_sha1_basic(refname, old_sha1, NULL, flags, type_p); -} - /* * Write an entry to the packed-refs file for the specified refname. * If peeled is non-NULL, write it as the entry's peeled value. @@ -2556,7 +2673,7 @@ static void prune_ref(struct ref_to_prune *r) transaction = ref_transaction_begin(&err); if (!transaction || ref_transaction_delete(transaction, r->name, r->sha1, - REF_ISPRUNING, 1, NULL, &err) || + REF_ISPRUNING, NULL, &err) || ref_transaction_commit(transaction, &err)) { ref_transaction_free(transaction); error("%s", err.buf); @@ -2661,15 +2778,16 @@ static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err) return 0; } -int delete_ref(const char *refname, const unsigned char *sha1, int delopt) +int delete_ref(const char *refname, const unsigned char *sha1, unsigned int flags) { struct ref_transaction *transaction; struct strbuf err = STRBUF_INIT; transaction = ref_transaction_begin(&err); if (!transaction || - ref_transaction_delete(transaction, refname, sha1, delopt, - sha1 && !is_null_sha1(sha1), NULL, &err) || + ref_transaction_delete(transaction, refname, + (sha1 && !is_null_sha1(sha1)) ? sha1 : NULL, + flags, NULL, &err) || ref_transaction_commit(transaction, &err)) { error("%s", err.buf); ref_transaction_free(transaction); @@ -2738,17 +2856,25 @@ static int rename_tmp_log(const char *newrefname) static int rename_ref_available(const char *oldname, const char *newname) { struct string_list skip = STRING_LIST_INIT_NODUP; + struct strbuf err = STRBUF_INIT; int ret; string_list_insert(&skip, oldname); - ret = is_refname_available(newname, &skip, get_packed_refs(&ref_cache)) - && is_refname_available(newname, &skip, get_loose_refs(&ref_cache)); + ret = !verify_refname_available(newname, NULL, &skip, + get_packed_refs(&ref_cache), &err) + && !verify_refname_available(newname, NULL, &skip, + get_loose_refs(&ref_cache), &err); + if (!ret) + error("%s", err.buf); + string_list_clear(&skip, 0); + strbuf_release(&err); return ret; } -static int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, - const char *logmsg); +static int write_ref_to_lockfile(struct ref_lock *lock, const unsigned char *sha1); +static int commit_ref_update(struct ref_lock *lock, + const unsigned char *sha1, const char *logmsg); int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg) { @@ -2758,6 +2884,7 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms struct stat loginfo; int log = !lstat(git_path("logs/%s", oldrefname), &loginfo); const char *symref = NULL; + struct strbuf err = STRBUF_INIT; if (log && S_ISLNK(loginfo.st_mode)) return error("reflog for %s is a symlink", oldrefname); @@ -2800,14 +2927,16 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms logmoved = log; - lock = lock_ref_sha1_basic(newrefname, NULL, NULL, 0, NULL); + lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, 0, NULL, &err); if (!lock) { - error("unable to lock %s for update", newrefname); + error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf); + strbuf_release(&err); goto rollback; } - lock->force_write = 1; hashcpy(lock->old_sha1, orig_sha1); - if (write_ref_sha1(lock, orig_sha1, logmsg)) { + + if (write_ref_to_lockfile(lock, orig_sha1) || + commit_ref_update(lock, orig_sha1, logmsg)) { error("unable to write current sha1 into %s", newrefname); goto rollback; } @@ -2815,16 +2944,17 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms return 0; rollback: - lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, 0, NULL); + lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, 0, NULL, &err); if (!lock) { - error("unable to lock %s for rollback", oldrefname); + error("unable to lock %s for rollback: %s", oldrefname, err.buf); + strbuf_release(&err); goto rollbacklog; } - lock->force_write = 1; flag = log_all_ref_updates; log_all_ref_updates = 0; - if (write_ref_sha1(lock, orig_sha1, NULL)) + if (write_ref_to_lockfile(lock, orig_sha1) || + commit_ref_update(lock, orig_sha1, NULL)) error("unable to write current sha1 into %s", oldrefname); log_all_ref_updates = flag; @@ -2840,7 +2970,7 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms return 1; } -int close_ref(struct ref_lock *lock) +static int close_ref(struct ref_lock *lock) { if (close_lock_file(lock->lk)) return -1; @@ -2848,7 +2978,7 @@ int close_ref(struct ref_lock *lock) return 0; } -int commit_ref(struct ref_lock *lock) +static int commit_ref(struct ref_lock *lock) { if (commit_lock_file(lock->lk)) return -1; @@ -2856,16 +2986,6 @@ int commit_ref(struct ref_lock *lock) return 0; } -void unlock_ref(struct ref_lock *lock) -{ - /* Do not free lock->lk -- atexit() still looks at them */ - if (lock->lk) - rollback_lock_file(lock->lk); - free(lock->ref_name); - free(lock->orig_ref_name); - free(lock); -} - /* * copy the reflog message msg to buf, which has been allocated sufficiently * large, while cleaning up the whitespaces. Especially, convert LF to space, @@ -2942,15 +3062,37 @@ int log_ref_setup(const char *refname, char *logfile, int bufsize) return 0; } +static int log_ref_write_fd(int fd, const unsigned char *old_sha1, + const unsigned char *new_sha1, + const char *committer, const char *msg) +{ + int msglen, written; + unsigned maxlen, len; + char *logrec; + + msglen = msg ? strlen(msg) : 0; + maxlen = strlen(committer) + msglen + 100; + logrec = xmalloc(maxlen); + len = sprintf(logrec, "%s %s %s\n", + sha1_to_hex(old_sha1), + sha1_to_hex(new_sha1), + committer); + if (msglen) + len += copy_msg(logrec + len - 1, msg) - 1; + + written = len <= maxlen ? write_in_full(fd, logrec, len) : -1; + free(logrec); + if (written != len) + return -1; + + return 0; +} + static int log_ref_write(const char *refname, const unsigned char *old_sha1, const unsigned char *new_sha1, const char *msg) { - int logfd, result, written, oflags = O_APPEND | O_WRONLY; - unsigned maxlen, len; - int msglen; + int logfd, result, oflags = O_APPEND | O_WRONLY; char log_file[PATH_MAX]; - char *logrec; - const char *committer; if (log_all_ref_updates < 0) log_all_ref_updates = !is_bare_repository(); @@ -2962,19 +3104,9 @@ static int log_ref_write(const char *refname, const unsigned char *old_sha1, logfd = open(log_file, oflags); if (logfd < 0) return 0; - msglen = msg ? strlen(msg) : 0; - committer = git_committer_info(0); - maxlen = strlen(committer) + msglen + 100; - logrec = xmalloc(maxlen); - len = sprintf(logrec, "%s %s %s\n", - sha1_to_hex(old_sha1), - sha1_to_hex(new_sha1), - committer); - if (msglen) - len += copy_msg(logrec + len - 1, msg) - 1; - written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1; - free(logrec); - if (written != len) { + result = log_ref_write_fd(logfd, old_sha1, new_sha1, + git_committer_info(0), msg); + if (result) { int save_errno = errno; close(logfd); error("Unable to append to %s", log_file); @@ -2996,23 +3128,15 @@ int is_branch(const char *refname) } /* - * Write sha1 into the ref specified by the lock. Make sure that errno - * is sane on error. + * Write sha1 into the open lockfile, then close the lockfile. On + * errors, rollback the lockfile and set errno to reflect the problem. */ -static int write_ref_sha1(struct ref_lock *lock, - const unsigned char *sha1, const char *logmsg) +static int write_ref_to_lockfile(struct ref_lock *lock, + const unsigned char *sha1) { static char term = '\n'; struct object *o; - if (!lock) { - errno = EINVAL; - return -1; - } - if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) { - unlock_ref(lock); - return 0; - } o = parse_object(sha1); if (!o) { error("Trying to write ref %s with nonexistent object %s", @@ -3037,6 +3161,17 @@ static int write_ref_sha1(struct ref_lock *lock, errno = save_errno; return -1; } + return 0; +} + +/* + * Commit a change to a loose reference that has already been written + * to the loose reference lockfile. Also update the reflogs if + * necessary, using the specified lockmsg (which can be NULL). + */ +static int commit_ref_update(struct ref_lock *lock, + const unsigned char *sha1, const char *logmsg) +{ clear_loose_ref_cache(&ref_cache); if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 || (strcmp(lock->ref_name, lock->orig_ref_name) && @@ -3482,16 +3617,27 @@ int for_each_reflog(each_ref_fn fn, void *cb_data) } /** - * Information needed for a single ref update. Set new_sha1 to the - * new value or to zero to delete the ref. To check the old value - * while locking the ref, set have_old to 1 and set old_sha1 to the - * value or to zero to ensure the ref does not exist before update. + * Information needed for a single ref update. Set new_sha1 to the new + * value or to null_sha1 to delete the ref. To check the old value + * while the ref is locked, set (flags & REF_HAVE_OLD) and set + * old_sha1 to the old value, or to null_sha1 to ensure the ref does + * not exist before update. */ struct ref_update { + /* + * If (flags & REF_HAVE_NEW), set the reference to this value: + */ unsigned char new_sha1[20]; + /* + * If (flags & REF_HAVE_OLD), check that the reference + * previously had this value: + */ unsigned char old_sha1[20]; - int flags; /* REF_NODEREF? */ - int have_old; /* 1 if old_sha1 is valid, 0 otherwise */ + /* + * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF, + * REF_DELETING, and REF_ISPRUNING: + */ + unsigned int flags; struct ref_lock *lock; int type; char *msg; @@ -3563,7 +3709,7 @@ int ref_transaction_update(struct ref_transaction *transaction, const char *refname, const unsigned char *new_sha1, const unsigned char *old_sha1, - int flags, int have_old, const char *msg, + unsigned int flags, const char *msg, struct strbuf *err) { struct ref_update *update; @@ -3573,10 +3719,7 @@ int ref_transaction_update(struct ref_transaction *transaction, if (transaction->state != REF_TRANSACTION_OPEN) die("BUG: update called for transaction that is not open"); - if (have_old && !old_sha1) - die("BUG: have_old is true but old_sha1 is NULL"); - - if (!is_null_sha1(new_sha1) && + if (new_sha1 && !is_null_sha1(new_sha1) && check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { strbuf_addf(err, "refusing to update ref with bad name %s", refname); @@ -3584,11 +3727,15 @@ int ref_transaction_update(struct ref_transaction *transaction, } update = add_update(transaction, refname); - hashcpy(update->new_sha1, new_sha1); - update->flags = flags; - update->have_old = have_old; - if (have_old) + if (new_sha1) { + hashcpy(update->new_sha1, new_sha1); + flags |= REF_HAVE_NEW; + } + if (old_sha1) { hashcpy(update->old_sha1, old_sha1); + flags |= REF_HAVE_OLD; + } + update->flags = flags; if (msg) update->msg = xstrdup(msg); return 0; @@ -3597,75 +3744,52 @@ int ref_transaction_update(struct ref_transaction *transaction, int ref_transaction_create(struct ref_transaction *transaction, const char *refname, const unsigned char *new_sha1, - int flags, const char *msg, + unsigned int flags, const char *msg, struct strbuf *err) { - struct ref_update *update; - - assert(err); - - if (transaction->state != REF_TRANSACTION_OPEN) - die("BUG: create called for transaction that is not open"); - if (!new_sha1 || is_null_sha1(new_sha1)) - die("BUG: create ref with null new_sha1"); - - if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { - strbuf_addf(err, "refusing to create ref with bad name %s", - refname); - return -1; - } - - update = add_update(transaction, refname); - - hashcpy(update->new_sha1, new_sha1); - hashclr(update->old_sha1); - update->flags = flags; - update->have_old = 1; - if (msg) - update->msg = xstrdup(msg); - return 0; + die("BUG: create called without valid new_sha1"); + return ref_transaction_update(transaction, refname, new_sha1, + null_sha1, flags, msg, err); } int ref_transaction_delete(struct ref_transaction *transaction, const char *refname, const unsigned char *old_sha1, - int flags, int have_old, const char *msg, + unsigned int flags, const char *msg, struct strbuf *err) { - struct ref_update *update; - - assert(err); - - if (transaction->state != REF_TRANSACTION_OPEN) - die("BUG: delete called for transaction that is not open"); - - if (have_old && !old_sha1) - die("BUG: have_old is true but old_sha1 is NULL"); + if (old_sha1 && is_null_sha1(old_sha1)) + die("BUG: delete called with old_sha1 set to zeros"); + return ref_transaction_update(transaction, refname, + null_sha1, old_sha1, + flags, msg, err); +} - update = add_update(transaction, refname); - update->flags = flags; - update->have_old = have_old; - if (have_old) { - assert(!is_null_sha1(old_sha1)); - hashcpy(update->old_sha1, old_sha1); - } - if (msg) - update->msg = xstrdup(msg); - return 0; +int ref_transaction_verify(struct ref_transaction *transaction, + const char *refname, + const unsigned char *old_sha1, + unsigned int flags, + struct strbuf *err) +{ + if (!old_sha1) + die("BUG: verify called with old_sha1 set to NULL"); + return ref_transaction_update(transaction, refname, + NULL, old_sha1, + flags, NULL, err); } -int update_ref(const char *action, const char *refname, - const unsigned char *sha1, const unsigned char *oldval, - int flags, enum action_on_err onerr) +int update_ref(const char *msg, const char *refname, + const unsigned char *new_sha1, const unsigned char *old_sha1, + unsigned int flags, enum action_on_err onerr) { struct ref_transaction *t; struct strbuf err = STRBUF_INIT; t = ref_transaction_begin(&err); if (!t || - ref_transaction_update(t, refname, sha1, oldval, flags, - !!oldval, action, &err) || + ref_transaction_update(t, refname, new_sha1, old_sha1, + flags, msg, &err) || ref_transaction_commit(t, &err)) { const char *str = "update_ref failed for ref '%s': %s"; @@ -3688,25 +3812,18 @@ int update_ref(const char *action, const char *refname, return 0; } -static int ref_update_compare(const void *r1, const void *r2) -{ - const struct ref_update * const *u1 = r1; - const struct ref_update * const *u2 = r2; - return strcmp((*u1)->refname, (*u2)->refname); -} - -static int ref_update_reject_duplicates(struct ref_update **updates, int n, +static int ref_update_reject_duplicates(struct string_list *refnames, struct strbuf *err) { - int i; + int i, n = refnames->nr; assert(err); for (i = 1; i < n; i++) - if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) { + if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) { strbuf_addf(err, "Multiple updates for ref '%s' not allowed.", - updates[i]->refname); + refnames->items[i].string); return 1; } return 0; @@ -3720,6 +3837,7 @@ int ref_transaction_commit(struct ref_transaction *transaction, struct ref_update **updates = transaction->updates; struct string_list refs_to_delete = STRING_LIST_INIT_NODUP; struct string_list_item *ref_to_delete; + struct string_list affected_refnames = STRING_LIST_INIT_NODUP; assert(err); @@ -3731,51 +3849,103 @@ int ref_transaction_commit(struct ref_transaction *transaction, return 0; } - /* Copy, sort, and reject duplicate refs */ - qsort(updates, n, sizeof(*updates), ref_update_compare); - if (ref_update_reject_duplicates(updates, n, err)) { + /* Fail if a refname appears more than once in the transaction: */ + for (i = 0; i < n; i++) + string_list_append(&affected_refnames, updates[i]->refname); + string_list_sort(&affected_refnames); + if (ref_update_reject_duplicates(&affected_refnames, err)) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; } - /* Acquire all locks while verifying old values */ + /* + * Acquire all locks, verify old values if provided, check + * that new values are valid, and write new values to the + * lockfiles, ready to be activated. Only keep one lockfile + * open at a time to avoid running out of file descriptors. + */ for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; - int flags = update->flags; - - if (is_null_sha1(update->new_sha1)) - flags |= REF_DELETING; - update->lock = lock_ref_sha1_basic(update->refname, - (update->have_old ? - update->old_sha1 : - NULL), - NULL, - flags, - &update->type); + + if ((update->flags & REF_HAVE_NEW) && + is_null_sha1(update->new_sha1)) + update->flags |= REF_DELETING; + update->lock = lock_ref_sha1_basic( + update->refname, + ((update->flags & REF_HAVE_OLD) ? + update->old_sha1 : NULL), + &affected_refnames, NULL, + update->flags, + &update->type, + err); if (!update->lock) { + char *reason; + ret = (errno == ENOTDIR) ? TRANSACTION_NAME_CONFLICT : TRANSACTION_GENERIC_ERROR; - strbuf_addf(err, "Cannot lock the ref '%s'.", - update->refname); + reason = strbuf_detach(err, NULL); + strbuf_addf(err, "Cannot lock ref '%s': %s", + update->refname, reason); + free(reason); goto cleanup; } + if ((update->flags & REF_HAVE_NEW) && + !(update->flags & REF_DELETING)) { + int overwriting_symref = ((update->type & REF_ISSYMREF) && + (update->flags & REF_NODEREF)); + + if (!overwriting_symref && + !hashcmp(update->lock->old_sha1, update->new_sha1)) { + /* + * The reference already has the desired + * value, so we don't need to write it. + */ + } else if (write_ref_to_lockfile(update->lock, + update->new_sha1)) { + /* + * The lock was freed upon failure of + * write_ref_to_lockfile(): + */ + update->lock = NULL; + strbuf_addf(err, "Cannot update the ref '%s'.", + update->refname); + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } else { + update->flags |= REF_NEEDS_COMMIT; + } + } + if (!(update->flags & REF_NEEDS_COMMIT)) { + /* + * We didn't have to write anything to the lockfile. + * Close it to free up the file descriptor: + */ + if (close_ref(update->lock)) { + strbuf_addf(err, "Couldn't close %s.lock", + update->refname); + goto cleanup; + } + } } /* Perform updates first so live commits remain referenced */ for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; - if (!is_null_sha1(update->new_sha1)) { - if (write_ref_sha1(update->lock, update->new_sha1, - update->msg)) { - update->lock = NULL; /* freed by write_ref_sha1 */ + if (update->flags & REF_NEEDS_COMMIT) { + if (commit_ref_update(update->lock, + update->new_sha1, update->msg)) { + /* freed by commit_ref_update(): */ + update->lock = NULL; strbuf_addf(err, "Cannot update the ref '%s'.", update->refname); ret = TRANSACTION_GENERIC_ERROR; goto cleanup; + } else { + /* freed by commit_ref_update(): */ + update->lock = NULL; } - update->lock = NULL; /* freed by write_ref_sha1 */ } } @@ -3783,7 +3953,7 @@ int ref_transaction_commit(struct ref_transaction *transaction, for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; - if (update->lock) { + if (update->flags & REF_DELETING) { if (delete_ref_loose(update->lock, update->type, err)) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; @@ -3810,6 +3980,7 @@ cleanup: if (updates[i]->lock) unlock_ref(updates[i]->lock); string_list_clear(&refs_to_delete, 0); + string_list_clear(&affected_refnames, 0); return ret; } @@ -3948,3 +4119,145 @@ int ref_is_hidden(const char *refname) } return 0; } + +struct expire_reflog_cb { + unsigned int flags; + reflog_expiry_should_prune_fn *should_prune_fn; + void *policy_cb; + FILE *newlog; + unsigned char last_kept_sha1[20]; +}; + +static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1, + const char *email, unsigned long timestamp, int tz, + const char *message, void *cb_data) +{ + struct expire_reflog_cb *cb = cb_data; + struct expire_reflog_policy_cb *policy_cb = cb->policy_cb; + + if (cb->flags & EXPIRE_REFLOGS_REWRITE) + osha1 = cb->last_kept_sha1; + + if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz, + message, policy_cb)) { + if (!cb->newlog) + printf("would prune %s", message); + else if (cb->flags & EXPIRE_REFLOGS_VERBOSE) + printf("prune %s", message); + } else { + if (cb->newlog) { + fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s", + sha1_to_hex(osha1), sha1_to_hex(nsha1), + email, timestamp, tz, message); + hashcpy(cb->last_kept_sha1, nsha1); + } + if (cb->flags & EXPIRE_REFLOGS_VERBOSE) + printf("keep %s", message); + } + return 0; +} + +int reflog_expire(const char *refname, const unsigned char *sha1, + unsigned int flags, + reflog_expiry_prepare_fn prepare_fn, + reflog_expiry_should_prune_fn should_prune_fn, + reflog_expiry_cleanup_fn cleanup_fn, + void *policy_cb_data) +{ + static struct lock_file reflog_lock; + struct expire_reflog_cb cb; + struct ref_lock *lock; + char *log_file; + int status = 0; + int type; + struct strbuf err = STRBUF_INIT; + + memset(&cb, 0, sizeof(cb)); + cb.flags = flags; + cb.policy_cb = policy_cb_data; + cb.should_prune_fn = should_prune_fn; + + /* + * The reflog file is locked by holding the lock on the + * reference itself, plus we might need to update the + * reference if --updateref was specified: + */ + lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, 0, &type, &err); + if (!lock) { + error("cannot lock ref '%s': %s", refname, err.buf); + strbuf_release(&err); + return -1; + } + if (!reflog_exists(refname)) { + unlock_ref(lock); + return 0; + } + + log_file = git_pathdup("logs/%s", refname); + if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) { + /* + * Even though holding $GIT_DIR/logs/$reflog.lock has + * no locking implications, we use the lock_file + * machinery here anyway because it does a lot of the + * work we need, including cleaning up if the program + * exits unexpectedly. + */ + if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) { + struct strbuf err = STRBUF_INIT; + unable_to_lock_message(log_file, errno, &err); + error("%s", err.buf); + strbuf_release(&err); + goto failure; + } + cb.newlog = fdopen_lock_file(&reflog_lock, "w"); + if (!cb.newlog) { + error("cannot fdopen %s (%s)", + reflog_lock.filename.buf, strerror(errno)); + goto failure; + } + } + + (*prepare_fn)(refname, sha1, cb.policy_cb); + for_each_reflog_ent(refname, expire_reflog_ent, &cb); + (*cleanup_fn)(cb.policy_cb); + + if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) { + /* + * It doesn't make sense to adjust a reference pointed + * to by a symbolic ref based on expiring entries in + * the symbolic reference's reflog. Nor can we update + * a reference if there are no remaining reflog + * entries. + */ + int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) && + !(type & REF_ISSYMREF) && + !is_null_sha1(cb.last_kept_sha1); + + if (close_lock_file(&reflog_lock)) { + status |= error("couldn't write %s: %s", log_file, + strerror(errno)); + } else if (update && + (write_in_full(lock->lock_fd, + sha1_to_hex(cb.last_kept_sha1), 40) != 40 || + write_str_in_full(lock->lock_fd, "\n") != 1 || + close_ref(lock) < 0)) { + status |= error("couldn't write %s", + lock->lk->filename.buf); + rollback_lock_file(&reflog_lock); + } else if (commit_lock_file(&reflog_lock)) { + status |= error("unable to commit reflog '%s' (%s)", + log_file, strerror(errno)); + } else if (update && commit_ref(lock)) { + status |= error("couldn't set %s", lock->ref_name); + } + } + free(log_file); + unlock_ref(lock); + return status; + + failure: + rollback_lock_file(&reflog_lock); + free(log_file); + unlock_ref(lock); + return -1; +} |