diff options
Diffstat (limited to 'refs.c')
| -rw-r--r-- | refs.c | 823 |
1 files changed, 535 insertions, 288 deletions
@@ -1,4 +1,5 @@ #include "cache.h" +#include "lockfile.h" #include "refs.h" #include "object.h" #include "tag.h" @@ -25,6 +26,11 @@ static unsigned char refname_disposition[256] = { }; /* + * Used as a flag to ref_transaction_delete when a loose ref is being + * pruned. + */ +#define REF_ISPRUNING 0x0100 +/* * Try to read one refname component from the front of refname. * Return the length of the component found, or -1 if the component is * not legal. It is legal if it is something reasonable to have under @@ -64,17 +70,10 @@ static int check_refname_component(const char *refname, int flags) out: if (cp == refname) return 0; /* Component has zero length. */ - if (refname[0] == '.') { - if (!(flags & REFNAME_DOT_COMPONENT)) - return -1; /* Component starts with '.'. */ - /* - * Even if leading dots are allowed, don't allow "." - * as a component (".." is prevented by a rule above). - */ - if (refname[1] == '\0') - return -1; /* Component equals ".". */ - } - if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5)) + if (refname[0] == '.') + return -1; /* Component starts with '.'. */ + if (cp - refname >= LOCK_SUFFIX_LEN && + !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN)) return -1; /* Refname ends with ".lock". */ return cp - refname; } @@ -188,8 +187,8 @@ struct ref_dir { /* * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, - * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see - * refs.h. + * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are + * public values; see refs.h. */ /* @@ -197,16 +196,16 @@ struct ref_dir { * the correct peeled value for the reference, which might be * null_sha1 if the reference is not a tag or if it is broken. */ -#define REF_KNOWS_PEELED 0x08 +#define REF_KNOWS_PEELED 0x10 /* ref_entry represents a directory of references */ -#define REF_DIR 0x10 +#define REF_DIR 0x20 /* * Entry has not yet been read from disk (used only for REF_DIR * entries representing loose references) */ -#define REF_INCOMPLETE 0x20 +#define REF_INCOMPLETE 0x40 /* * A ref_entry represents either a reference or a "subdirectory" of @@ -275,6 +274,39 @@ static struct ref_dir *get_ref_dir(struct ref_entry *entry) return dir; } +/* + * Check if a refname is safe. + * For refs that start with "refs/" we consider it safe as long they do + * not try to resolve to outside of refs/. + * + * For all other refs we only consider them safe iff they only contain + * upper case characters and '_' (like "HEAD" AND "MERGE_HEAD", and not like + * "config"). + */ +static int refname_is_safe(const char *refname) +{ + if (starts_with(refname, "refs/")) { + char *buf; + int result; + + buf = xmalloc(strlen(refname) + 1); + /* + * Does the refname try to escape refs/? + * For example: refs/foo/../bar is safe but refs/foo/../../bar + * is not. + */ + result = !normalize_path_copy(buf, refname + strlen("refs/")); + free(buf); + return result; + } + while (*refname) { + if (!isupper(*refname) && *refname != '_') + return 0; + refname++; + } + return 1; +} + static struct ref_entry *create_ref_entry(const char *refname, const unsigned char *sha1, int flag, int check_name) @@ -283,8 +315,10 @@ static struct ref_entry *create_ref_entry(const char *refname, struct ref_entry *ref; if (check_name && - check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT)) + check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) die("Reference has invalid format: '%s'", refname); + if (!check_name && !refname_is_safe(refname)) + die("Reference has invalid name: '%s'", refname); len = strlen(refname) + 1; ref = xmalloc(sizeof(struct ref_entry) + len); hashcpy(ref->u.value.sha1, sha1); @@ -779,60 +813,121 @@ static void prime_ref_dir(struct ref_dir *dir) prime_ref_dir(get_ref_dir(entry)); } } -/* - * Return true iff refname1 and refname2 conflict with each other. - * 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". - */ -static int names_conflict(const char *refname1, const char *refname2) + +static int entry_matches(struct ref_entry *entry, const struct string_list *list) { - for (; *refname1 && *refname1 == *refname2; refname1++, refname2++) - ; - return (*refname1 == '\0' && *refname2 == '/') - || (*refname1 == '/' && *refname2 == '\0'); + return list && string_list_has_string(list, entry->name); } -struct name_conflict_cb { - const char *refname; - const char *oldrefname; - const char *conflicting_refname; +struct nonmatching_ref_data { + const struct string_list *skip; + struct ref_entry *found; }; -static int name_conflict_fn(struct ref_entry *entry, void *cb_data) +static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) { - struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data; - if (data->oldrefname && !strcmp(data->oldrefname, entry->name)) + struct nonmatching_ref_data *data = vdata; + + if (entry_matches(entry, data->skip)) return 0; - if (names_conflict(data->refname, entry->name)) { - data->conflicting_refname = entry->name; - return 1; - } - return 0; + + data->found = entry; + 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 - * oldrefname is non-NULL, ignore potential conflicts with oldrefname - * (e.g., because oldrefname is scheduled for deletion in the same + * skip is non-NULL, ignore potential conflicts with refs in skip + * (e.g., because they are scheduled for deletion in the same * operation). + * + * 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". + * + * skip must be sorted. */ -static int is_refname_available(const char *refname, const char *oldrefname, +static int is_refname_available(const char *refname, + const struct string_list *skip, struct ref_dir *dir) { - struct name_conflict_cb data; - data.refname = refname; - data.oldrefname = oldrefname; - data.conflicting_refname = NULL; + const char *slash; + size_t len; + int pos; + char *dirname; - sort_ref_dir(dir); - if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) { - error("'%s' exists; cannot create '%s'", - data.conflicting_refname, refname); + for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { + /* + * 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". + */ + 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; + } + + + /* + * 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. + */ + pos = search_ref_dir(dir, refname, slash + 1 - refname); + if (pos < 0) + return 1; + + 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. + */ + len = strlen(refname); + dirname = xmallocz(len + 1); + sprintf(dirname, "%s/", refname); + pos = search_ref_dir(dir, dirname, len + 1); + free(dirname); + + if (pos >= 0) { + /* + * We found a directory named "refname". It is a + * problem iff it contains any ref that is not + * in "skip". + */ + struct ref_entry *entry = dir->entries[pos]; + struct ref_dir *dir = get_ref_dir(entry); + struct nonmatching_ref_data data; + + data.skip = skip; + sort_ref_dir(dir); + if (!do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) + return 1; + + report_refname_conflict(data.found, refname); return 0; } + + /* + * 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; } @@ -1051,7 +1146,13 @@ static void read_packed_refs(FILE *f, struct ref_dir *dir) refname = parse_ref_line(refline, sha1); if (refname) { - last = create_ref_entry(refname, sha1, REF_ISPACKED, 1); + int flag = REF_ISPACKED; + + if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { + hashclr(sha1); + flag |= REF_BAD_NAME | REF_ISBROKEN; + } + last = create_ref_entry(refname, sha1, flag, 0); if (peeled == PEELED_FULLY || (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/"))) last->flag |= REF_KNOWS_PEELED; @@ -1183,12 +1284,19 @@ static void read_loose_refs(const char *dirname, struct ref_dir *dir) hashclr(sha1); flag |= REF_ISBROKEN; } - } else if (read_ref_full(refname.buf, sha1, 1, &flag)) { + } else if (read_ref_full(refname.buf, + RESOLVE_REF_READING, + sha1, &flag)) { hashclr(sha1); flag |= REF_ISBROKEN; } + if (check_refname_format(refname.buf, + REFNAME_ALLOW_ONELEVEL)) { + hashclr(sha1); + flag |= REF_BAD_NAME | REF_ISBROKEN; + } add_entry_to_dir(dir, - create_ref_entry(refname.buf, sha1, flag, 1)); + create_ref_entry(refname.buf, sha1, flag, 0)); } strbuf_setlen(&refname, dirnamelen); } @@ -1307,10 +1415,10 @@ static struct ref_entry *get_packed_ref(const char *refname) * A loose ref file doesn't exist; check for a packed ref. The * options are forwarded from resolve_safe_unsafe(). */ -static const char *handle_missing_loose_ref(const char *refname, - unsigned char *sha1, - int reading, - int *flag) +static int resolve_missing_loose_ref(const char *refname, + int resolve_flags, + unsigned char *sha1, + int *flags) { struct ref_entry *entry; @@ -1321,35 +1429,51 @@ static const char *handle_missing_loose_ref(const char *refname, entry = get_packed_ref(refname); if (entry) { hashcpy(sha1, entry->u.value.sha1); - if (flag) - *flag |= REF_ISPACKED; - return refname; + if (flags) + *flags |= REF_ISPACKED; + return 0; } /* The reference is not a packed reference, either. */ - if (reading) { - return NULL; + if (resolve_flags & RESOLVE_REF_READING) { + errno = ENOENT; + return -1; } else { hashclr(sha1); - return refname; + return 0; } } /* This function needs to return a meaningful errno on failure */ -const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag) +const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned char *sha1, int *flags) { int depth = MAXDEPTH; ssize_t len; char buffer[256]; static char refname_buffer[256]; + int bad_name = 0; - if (flag) - *flag = 0; + if (flags) + *flags = 0; if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { - errno = EINVAL; - return NULL; - } + if (flags) + *flags |= REF_BAD_NAME; + if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) || + !refname_is_safe(refname)) { + errno = EINVAL; + return NULL; + } + /* + * dwim_ref() uses REF_ISBROKEN to distinguish between + * missing refs and refs that were present but invalid, + * to complain about the latter to stderr. + * + * We don't know whether the ref exists, so don't set + * REF_ISBROKEN yet. + */ + bad_name = 1; + } for (;;) { char path[PATH_MAX]; struct stat st; @@ -1374,11 +1498,17 @@ const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int rea */ stat_ref: if (lstat(path, &st) < 0) { - if (errno == ENOENT) - return handle_missing_loose_ref(refname, sha1, - reading, flag); - else + if (errno != ENOENT) + return NULL; + if (resolve_missing_loose_ref(refname, resolve_flags, + sha1, flags)) return NULL; + if (bad_name) { + hashclr(sha1); + if (flags) + *flags |= REF_ISBROKEN; + } + return refname; } /* Follow "normalized" - ie "refs/.." symlinks by hand */ @@ -1396,8 +1526,12 @@ const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int rea !check_refname_format(buffer, 0)) { strcpy(refname_buffer, buffer); refname = refname_buffer; - if (flag) - *flag |= REF_ISSYMREF; + if (flags) + *flags |= REF_ISSYMREF; + if (resolve_flags & RESOLVE_REF_NO_RECURSE) { + hashclr(sha1); + return refname; + } continue; } } @@ -1442,31 +1576,45 @@ const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int rea */ if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) { - if (flag) - *flag |= REF_ISBROKEN; + if (flags) + *flags |= REF_ISBROKEN; errno = EINVAL; return NULL; } + if (bad_name) { + hashclr(sha1); + if (flags) + *flags |= REF_ISBROKEN; + } return refname; } - if (flag) - *flag |= REF_ISSYMREF; + if (flags) + *flags |= REF_ISSYMREF; buf = buffer + 4; while (isspace(*buf)) buf++; + refname = strcpy(refname_buffer, buf); + if (resolve_flags & RESOLVE_REF_NO_RECURSE) { + hashclr(sha1); + return refname; + } if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) { - if (flag) - *flag |= REF_ISBROKEN; - errno = EINVAL; - return NULL; + if (flags) + *flags |= REF_ISBROKEN; + + if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) || + !refname_is_safe(buf)) { + errno = EINVAL; + return NULL; + } + bad_name = 1; } - refname = strcpy(refname_buffer, buf); } } -char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag) +char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags) { - const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag); + const char *ret = resolve_ref_unsafe(ref, resolve_flags, sha1, flags); return ret ? xstrdup(ret) : NULL; } @@ -1477,22 +1625,22 @@ struct ref_filter { void *cb_data; }; -int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags) +int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags) { - if (resolve_ref_unsafe(refname, sha1, reading, flags)) + if (resolve_ref_unsafe(refname, resolve_flags, sha1, flags)) return 0; return -1; } int read_ref(const char *refname, unsigned char *sha1) { - return read_ref_full(refname, sha1, 1, NULL); + return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL); } int ref_exists(const char *refname) { unsigned char sha1[20]; - return !!resolve_ref_unsafe(refname, sha1, 1, NULL); + return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL); } static int filter_refs(const char *refname, const unsigned char *sha1, int flags, @@ -1605,7 +1753,7 @@ int peel_ref(const char *refname, unsigned char *sha1) return 0; } - if (read_ref_full(refname, base, 1, &flag)) + if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag)) return -1; /* @@ -1646,7 +1794,7 @@ static int warn_if_dangling_symref(const char *refname, const unsigned char *sha if (!(flags & REF_ISSYMREF)) return 0; - resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL); + resolves_to = resolve_ref_unsafe(refname, 0, junk, NULL); if (!resolves_to || (d->refname ? strcmp(resolves_to, d->refname) @@ -1771,7 +1919,7 @@ static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data) return 0; } - if (!read_ref_full("HEAD", sha1, 1, &flag)) + if (!read_ref_full("HEAD", RESOLVE_REF_READING, sha1, &flag)) return fn("HEAD", sha1, flag, cb_data); return 0; @@ -1851,7 +1999,7 @@ int head_ref_namespaced(each_ref_fn fn, void *cb_data) int flag; strbuf_addf(&buf, "%sHEAD", get_git_namespace()); - if (!read_ref_full(buf.buf, sha1, 1, &flag)) + if (!read_ref_full(buf.buf, RESOLVE_REF_READING, sha1, &flag)) ret = fn(buf.buf, sha1, flag, cb_data); strbuf_release(&buf); @@ -1946,7 +2094,9 @@ int refname_match(const char *abbrev_name, const char *full_name) static struct ref_lock *verify_lock(struct ref_lock *lock, const unsigned char *old_sha1, int mustexist) { - if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) { + if (read_ref_full(lock->ref_name, + mustexist ? RESOLVE_REF_READING : 0, + lock->old_sha1, NULL)) { int save_errno = errno; error("Can't verify ref %s", lock->ref_name); unlock_ref(lock); @@ -2019,7 +2169,8 @@ int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref) this_result = refs_found ? sha1_from_ref : sha1; mksnpath(fullref, sizeof(fullref), *p, len, str); - r = resolve_ref_unsafe(fullref, this_result, 1, &flag); + r = resolve_ref_unsafe(fullref, RESOLVE_REF_READING, + this_result, &flag); if (r) { if (!refs_found++) *ref = xstrdup(r); @@ -2048,7 +2199,8 @@ int dwim_log(const char *str, int len, unsigned char *sha1, char **log) const char *ref, *it; mksnpath(path, sizeof(path), *p, len, str); - ref = resolve_ref_unsafe(path, hash, 1, NULL); + ref = resolve_ref_unsafe(path, RESOLVE_REF_READING, + hash, NULL); if (!ref) continue; if (reflog_exists(path)) @@ -2068,9 +2220,13 @@ int dwim_log(const char *str, int len, unsigned char *sha1, char **log) return logs_found; } -/* This function should make sure errno is meaningful on error */ +/* + * Locks a ref returning the lock on success and NULL on failure. + * On failure errno is set to something meaningful. + */ static struct ref_lock *lock_ref_sha1_basic(const char *refname, const unsigned char *old_sha1, + const struct string_list *skip, int flags, int *type_p) { char *ref_file; @@ -2079,13 +2235,23 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, int last_errno = 0; int type, lflags; int mustexist = (old_sha1 && !is_null_sha1(old_sha1)); + int resolve_flags = 0; int missing = 0; int attempts_remaining = 3; lock = xcalloc(1, sizeof(struct ref_lock)); lock->lock_fd = -1; - refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type); + if (mustexist) + resolve_flags |= RESOLVE_REF_READING; + if (flags & REF_DELETING) { + resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME; + if (flags & REF_NODEREF) + resolve_flags |= RESOLVE_REF_NO_RECURSE; + } + + refname = resolve_ref_unsafe(refname, resolve_flags, + lock->old_sha1, &type); if (!refname && errno == EISDIR) { /* we are trying to lock foo but we used to * have foo/bar which now does not exist; @@ -2098,7 +2264,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, error("there are still refs under '%s'", orig_refname); goto error_return; } - refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type); + refname = resolve_ref_unsafe(orig_refname, resolve_flags, + lock->old_sha1, &type); } if (type_p) *type_p = type; @@ -2115,7 +2282,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, * name is a proper prefix of our refname. */ if (missing && - !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) { + !is_refname_available(refname, skip, get_packed_refs(&ref_cache))) { last_errno = ENOTDIR; goto error_return; } @@ -2125,7 +2292,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, lflags = 0; if (flags & REF_NODEREF) { refname = orig_refname; - lflags |= LOCK_NODEREF; + lflags |= LOCK_NO_DEREF; } lock->ref_name = xstrdup(refname); lock->orig_ref_name = xstrdup(orig_refname); @@ -2159,7 +2326,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, */ goto retry; else - unable_to_lock_index_die(ref_file, errno); + unable_to_lock_die(ref_file, errno); } return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock; @@ -2169,47 +2336,23 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, return NULL; } -struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1) -{ - char refpath[PATH_MAX]; - if (check_refname_format(refname, 0)) - return NULL; - strcpy(refpath, mkpath("refs/%s", refname)); - return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL); -} - struct ref_lock *lock_any_ref_for_update(const char *refname, const unsigned char *old_sha1, int flags, int *type_p) { - if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) - return NULL; - return lock_ref_sha1_basic(refname, old_sha1, flags, 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. */ -static void write_packed_entry(int fd, char *refname, unsigned char *sha1, +static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1, unsigned char *peeled) { - char line[PATH_MAX + 100]; - int len; - - len = snprintf(line, sizeof(line), "%s %s\n", - sha1_to_hex(sha1), refname); - /* this should not happen but just being defensive */ - if (len > sizeof(line)) - die("too long a refname '%s'", refname); - write_or_die(fd, line, len); - - if (peeled) { - if (snprintf(line, sizeof(line), "^%s\n", - sha1_to_hex(peeled)) != PEELED_LINE_LENGTH) - die("internal error"); - write_or_die(fd, line, PEELED_LINE_LENGTH); - } + fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname); + if (peeled) + fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled)); } /* @@ -2217,13 +2360,12 @@ static void write_packed_entry(int fd, char *refname, unsigned char *sha1, */ static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data) { - int *fd = cb_data; enum peel_status peel_status = peel_entry(entry, 0); if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG) error("internal error: %s is not a valid packed reference!", entry->name); - write_packed_entry(*fd, entry->name, entry->u.value.sha1, + write_packed_entry(cb_data, entry->name, entry->u.value.sha1, peel_status == PEEL_PEELED ? entry->u.value.peeled : NULL); return 0; @@ -2259,15 +2401,19 @@ int commit_packed_refs(void) get_packed_ref_cache(&ref_cache); int error = 0; int save_errno = 0; + FILE *out; if (!packed_ref_cache->lock) die("internal error: packed-refs not locked"); - write_or_die(packed_ref_cache->lock->fd, - PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER)); + out = fdopen_lock_file(packed_ref_cache->lock, "w"); + if (!out) + die_errno("unable to fdopen packed-refs descriptor"); + + fprintf_or_die(out, "%s", PACKED_REFS_HEADER); do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache), - 0, write_packed_entry_fn, - &packed_ref_cache->lock->fd); + 0, write_packed_entry_fn, out); + if (commit_lock_file(packed_ref_cache->lock)) { save_errno = errno; error = -1; @@ -2387,14 +2533,25 @@ static void try_remove_empty_parents(char *name) /* make sure nobody touched the ref, and unlink */ static void prune_ref(struct ref_to_prune *r) { - struct ref_lock *lock = lock_any_ref_for_update(r->name, r->sha1, - 0, NULL); + struct ref_transaction *transaction; + struct strbuf err = STRBUF_INIT; - if (lock) { - unlink_or_warn(git_path("%s", r->name)); - unlock_ref(lock); - try_remove_empty_parents(r->name); + if (check_refname_format(r->name, 0)) + return; + + transaction = ref_transaction_begin(&err); + if (!transaction || + ref_transaction_delete(transaction, r->name, r->sha1, + REF_ISPRUNING, 1, NULL, &err) || + ref_transaction_commit(transaction, &err)) { + ref_transaction_free(transaction); + error("%s", err.buf); + strbuf_release(&err); + return; } + ref_transaction_free(transaction); + strbuf_release(&err); + try_remove_empty_parents(r->name); } static void prune_refs(struct ref_to_prune *r) @@ -2450,7 +2607,7 @@ static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data) unsigned char sha1[20]; int flags; - if (read_ref_full(entry->name, sha1, 0, &flags)) + if (read_ref_full(entry->name, 0, sha1, &flags)) /* We should at least have found the packed ref. */ die("Internal error"); if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) { @@ -2489,6 +2646,8 @@ int repack_without_refs(const char **refnames, int n, struct strbuf *err) struct string_list_item *ref_to_delete; int i, ret, removed = 0; + assert(err); + /* Look for a packed ref */ for (i = 0; i < n; i++) if (get_packed_ref(refnames[i])) @@ -2499,13 +2658,8 @@ int repack_without_refs(const char **refnames, int n, struct strbuf *err) return 0; /* no refname exists in packed refs */ if (lock_packed_refs(0)) { - if (err) { - unable_to_lock_message(git_path("packed-refs"), errno, - err); - return -1; - } - unable_to_lock_error(git_path("packed-refs"), errno); - return error("cannot delete '%s' from packed refs", refnames[i]); + unable_to_lock_message(git_path("packed-refs"), errno, err); + return -1; } packed = get_packed_refs(&ref_cache); @@ -2531,27 +2685,25 @@ int repack_without_refs(const char **refnames, int n, struct strbuf *err) /* Write what remains */ ret = commit_packed_refs(); - if (ret && err) + if (ret) strbuf_addf(err, "unable to overwrite old ref-pack file: %s", strerror(errno)); return ret; } -static int repack_without_ref(const char *refname) +static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err) { - return repack_without_refs(&refname, 1, NULL); -} + assert(err); -static int delete_ref_loose(struct ref_lock *lock, int flag) -{ if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) { - /* loose */ - int err, i = strlen(lock->lk->filename) - 5; /* .lock */ - - lock->lk->filename[i] = 0; - err = unlink_or_warn(lock->lk->filename); - lock->lk->filename[i] = '.'; - if (err && errno != ENOENT) + /* + * loose. The loose file name is the same as the + * lockfile name, minus ".lock": + */ + char *loose_filename = get_locked_file_path(lock->lk); + int res = unlink_or_msg(loose_filename, err); + free(loose_filename); + if (res) return 1; } return 0; @@ -2559,24 +2711,22 @@ static int delete_ref_loose(struct ref_lock *lock, int flag) int delete_ref(const char *refname, const unsigned char *sha1, int delopt) { - struct ref_lock *lock; - int ret = 0, flag = 0; - - lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag); - if (!lock) + 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_commit(transaction, &err)) { + error("%s", err.buf); + ref_transaction_free(transaction); + strbuf_release(&err); return 1; - ret |= delete_ref_loose(lock, flag); - - /* removing the loose one could have resurrected an earlier - * packed one. Also, if it was not loose we need to repack - * without it. - */ - ret |= repack_without_ref(lock->ref_name); - - unlink_or_warn(git_path("logs/%s", lock->ref_name)); - clear_loose_ref_cache(&ref_cache); - unlock_ref(lock); - return ret; + } + ref_transaction_free(transaction); + strbuf_release(&err); + return 0; } /* @@ -2633,6 +2783,21 @@ static int rename_tmp_log(const char *newrefname) return 0; } +static int rename_ref_available(const char *oldname, const char *newname) +{ + struct string_list skip = STRING_LIST_INIT_NODUP; + 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)); + string_list_clear(&skip, 0); + return ret; +} + +static int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, + const char *logmsg); + int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg) { unsigned char sha1[20], orig_sha1[20]; @@ -2645,17 +2810,15 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms if (log && S_ISLNK(loginfo.st_mode)) return error("reflog for %s is a symlink", oldrefname); - symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag); + symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING, + orig_sha1, &flag); if (flag & REF_ISSYMREF) return error("refname %s is a symbolic ref, renaming it is not supported", oldrefname); if (!symref) return error("refname %s not found", oldrefname); - if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache))) - return 1; - - if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache))) + if (!rename_ref_available(oldrefname, newrefname)) return 1; if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG))) @@ -2667,7 +2830,7 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms goto rollback; } - if (!read_ref_full(newrefname, sha1, 1, &flag) && + if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) && delete_ref(newrefname, sha1, REF_NODEREF)) { if (errno==EISDIR) { if (remove_empty_directories(git_path("%s", newrefname))) { @@ -2685,7 +2848,7 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms logmoved = log; - lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL); + lock = lock_ref_sha1_basic(newrefname, NULL, NULL, 0, NULL); if (!lock) { error("unable to lock %s for update", newrefname); goto rollback; @@ -2700,7 +2863,7 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms return 0; rollback: - lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL); + lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, 0, NULL); if (!lock) { error("unable to lock %s for rollback", oldrefname); goto rollbacklog; @@ -2799,10 +2962,10 @@ int log_ref_setup(const char *refname, char *logfile, int bufsize) logfd = open(logfile, oflags, 0666); if (logfd < 0) { - if (!(oflags & O_CREAT) && errno == ENOENT) + if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR)) return 0; - if ((oflags & O_CREAT) && errno == EISDIR) { + if (errno == EISDIR) { if (remove_empty_directories(logfile)) { int save_errno = errno; error("There are still logs under '%s'", @@ -2880,8 +3043,11 @@ int is_branch(const char *refname) return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/"); } -/* This function must return a meaningful errno */ -int write_ref_sha1(struct ref_lock *lock, +/* + * Write sha1 into the ref specified by the lock. Make sure that errno + * is sane on error. + */ +static int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, const char *logmsg) { static char term = '\n'; @@ -2914,7 +3080,7 @@ int write_ref_sha1(struct ref_lock *lock, write_in_full(lock->lock_fd, &term, 1) != 1 || close_ref(lock) < 0) { int save_errno = errno; - error("Couldn't write %s", lock->lk->filename); + error("Couldn't write %s", lock->lk->filename.buf); unlock_ref(lock); errno = save_errno; return -1; @@ -2942,7 +3108,8 @@ int write_ref_sha1(struct ref_lock *lock, unsigned char head_sha1[20]; int head_flag; const char *head_ref; - head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag); + head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, + head_sha1, &head_flag); if (head_ref && (head_flag & REF_ISSYMREF) && !strcmp(head_ref, lock->ref_name)) log_ref_write("HEAD", lock->old_sha1, sha1, logmsg); @@ -3105,7 +3272,7 @@ static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1, return 1; } -int read_ref_at(const char *refname, unsigned long at_time, int cnt, +int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time, int cnt, unsigned char *sha1, char **msg, unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt) { @@ -3123,8 +3290,12 @@ int read_ref_at(const char *refname, unsigned long at_time, int cnt, for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb); - if (!cb.reccnt) - die("Log for %s is empty.", refname); + if (!cb.reccnt) { + if (flags & GET_SHA1_QUIETLY) + exit(128); + else + die("Log for %s is empty.", refname); + } if (cb.found_it) return 0; @@ -3309,7 +3480,7 @@ static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data retval = do_for_each_reflog(name, fn, cb_data); } else { unsigned char sha1[20]; - if (read_ref_full(name->buf, sha1, 0, NULL)) + if (read_ref_full(name->buf, 0, sha1, NULL)) retval = error("bad ref for %s", name->buf); else retval = fn(name->buf, sha1, 0, cb_data); @@ -3333,43 +3504,6 @@ int for_each_reflog(each_ref_fn fn, void *cb_data) return retval; } -static struct ref_lock *update_ref_lock(const char *refname, - const unsigned char *oldval, - int flags, int *type_p, - enum action_on_err onerr) -{ - struct ref_lock *lock; - lock = lock_any_ref_for_update(refname, oldval, flags, type_p); - if (!lock) { - const char *str = "Cannot lock the ref '%s'."; - switch (onerr) { - case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break; - case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break; - case UPDATE_REFS_QUIET_ON_ERR: break; - } - } - return lock; -} - -static int update_ref_write(const char *action, const char *refname, - const unsigned char *sha1, struct ref_lock *lock, - struct strbuf *err, enum action_on_err onerr) -{ - if (write_ref_sha1(lock, sha1, action) < 0) { - const char *str = "Cannot update the ref '%s'."; - if (err) - strbuf_addf(err, str, refname); - - switch (onerr) { - case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break; - case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break; - case UPDATE_REFS_QUIET_ON_ERR: break; - } - return 1; - } - return 0; -} - /** * 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 @@ -3383,10 +3517,26 @@ struct ref_update { int have_old; /* 1 if old_sha1 is valid, 0 otherwise */ struct ref_lock *lock; int type; + char *msg; const char refname[FLEX_ARRAY]; }; /* + * Transaction states. + * OPEN: The transaction is in a valid state and can accept new updates. + * An OPEN transaction can be committed. + * CLOSED: A closed transaction is no longer active and no other operations + * than free can be used on it in this state. + * A transaction can either become closed by successfully committing + * an active transaction or if there is a failure while building + * the transaction thus rendering it failed/inactive. + */ +enum ref_transaction_state { + REF_TRANSACTION_OPEN = 0, + REF_TRANSACTION_CLOSED = 1 +}; + +/* * Data structure for holding a reference transaction, which can * consist of checks and updates to multiple references, carried out * as atomically as possible. This structure is opaque to callers. @@ -3395,10 +3545,13 @@ struct ref_transaction { struct ref_update **updates; size_t alloc; size_t nr; + enum ref_transaction_state state; }; -struct ref_transaction *ref_transaction_begin(void) +struct ref_transaction *ref_transaction_begin(struct strbuf *err) { + assert(err); + return xcalloc(1, sizeof(struct ref_transaction)); } @@ -3409,9 +3562,10 @@ void ref_transaction_free(struct ref_transaction *transaction) if (!transaction) return; - for (i = 0; i < transaction->nr; i++) + for (i = 0; i < transaction->nr; i++) { + free(transaction->updates[i]->msg); free(transaction->updates[i]); - + } free(transaction->updates); free(transaction); } @@ -3432,61 +3586,129 @@ 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, + int flags, int have_old, const char *msg, struct strbuf *err) { struct ref_update *update; + assert(err); + + 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) && + check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { + strbuf_addf(err, "refusing to update ref with bad name %s", + refname); + return -1; + } + update = add_update(transaction, refname); hashcpy(update->new_sha1, new_sha1); update->flags = flags; update->have_old = have_old; if (have_old) hashcpy(update->old_sha1, old_sha1); + if (msg) + update->msg = xstrdup(msg); return 0; } -void ref_transaction_create(struct ref_transaction *transaction, - const char *refname, - const unsigned char *new_sha1, - int flags) +int ref_transaction_create(struct ref_transaction *transaction, + const char *refname, + const unsigned char *new_sha1, + int flags, const char *msg, + struct strbuf *err) { - struct ref_update *update = add_update(transaction, refname); + 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); - assert(!is_null_sha1(new_sha1)); 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; } -void ref_transaction_delete(struct ref_transaction *transaction, - const char *refname, - const unsigned char *old_sha1, - int flags, int have_old) +int ref_transaction_delete(struct ref_transaction *transaction, + const char *refname, + const unsigned char *old_sha1, + int flags, int have_old, const char *msg, + struct strbuf *err) { - struct ref_update *update = add_update(transaction, refname); + 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"); + + 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 update_ref(const char *action, const char *refname, const unsigned char *sha1, const unsigned char *oldval, int flags, enum action_on_err onerr) { - struct ref_lock *lock; - lock = update_ref_lock(refname, oldval, flags, NULL, onerr); - if (!lock) + 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_commit(t, &err)) { + const char *str = "update_ref failed for ref '%s': %s"; + + ref_transaction_free(t); + switch (onerr) { + case UPDATE_REFS_MSG_ON_ERR: + error(str, refname, err.buf); + break; + case UPDATE_REFS_DIE_ON_ERR: + die(str, refname, err.buf); + break; + case UPDATE_REFS_QUIET_ON_ERR: + break; + } + strbuf_release(&err); return 1; - return update_ref_write(action, refname, sha1, lock, NULL, onerr); + } + strbuf_release(&err); + ref_transaction_free(t); + return 0; } static int ref_update_compare(const void *r1, const void *r2) @@ -3500,53 +3722,67 @@ static int ref_update_reject_duplicates(struct ref_update **updates, int n, struct strbuf *err) { int i; + + assert(err); + for (i = 1; i < n; i++) if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) { - const char *str = - "Multiple updates for ref '%s' not allowed."; - if (err) - strbuf_addf(err, str, updates[i]->refname); - + strbuf_addf(err, + "Multiple updates for ref '%s' not allowed.", + updates[i]->refname); return 1; } return 0; } int ref_transaction_commit(struct ref_transaction *transaction, - const char *msg, struct strbuf *err) + struct strbuf *err) { int ret = 0, delnum = 0, i; const char **delnames; int n = transaction->nr; struct ref_update **updates = transaction->updates; - if (!n) + assert(err); + + if (transaction->state != REF_TRANSACTION_OPEN) + die("BUG: commit called for transaction that is not open"); + + if (!n) { + transaction->state = REF_TRANSACTION_CLOSED; return 0; + } /* Allocate work space */ delnames = xmalloc(sizeof(*delnames) * n); /* Copy, sort, and reject duplicate refs */ qsort(updates, n, sizeof(*updates), ref_update_compare); - ret = ref_update_reject_duplicates(updates, n, err); - if (ret) + if (ref_update_reject_duplicates(updates, n, err)) { + ret = TRANSACTION_GENERIC_ERROR; goto cleanup; + } /* Acquire all locks while verifying old values */ for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; - - update->lock = update_ref_lock(update->refname, - (update->have_old ? - update->old_sha1 : NULL), - update->flags, - &update->type, - UPDATE_REFS_QUIET_ON_ERR); + 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->lock) { - if (err) - strbuf_addf(err, "Cannot lock the ref '%s'.", - update->refname); - ret = 1; + ret = (errno == ENOTDIR) + ? TRANSACTION_NAME_CONFLICT + : TRANSACTION_GENERIC_ERROR; + strbuf_addf(err, "Cannot lock the ref '%s'.", + update->refname); goto cleanup; } } @@ -3556,14 +3792,15 @@ int ref_transaction_commit(struct ref_transaction *transaction, struct ref_update *update = updates[i]; if (!is_null_sha1(update->new_sha1)) { - ret = update_ref_write(msg, - update->refname, - update->new_sha1, - update->lock, err, - UPDATE_REFS_QUIET_ON_ERR); - update->lock = NULL; /* freed by update_ref_write */ - if (ret) + if (write_ref_sha1(update->lock, update->new_sha1, + update->msg)) { + update->lock = NULL; /* freed by write_ref_sha1 */ + strbuf_addf(err, "Cannot update the ref '%s'.", + update->refname); + ret = TRANSACTION_GENERIC_ERROR; goto cleanup; + } + update->lock = NULL; /* freed by write_ref_sha1 */ } } @@ -3572,17 +3809,27 @@ int ref_transaction_commit(struct ref_transaction *transaction, struct ref_update *update = updates[i]; if (update->lock) { - delnames[delnum++] = update->lock->ref_name; - ret |= delete_ref_loose(update->lock, update->type); + if (delete_ref_loose(update->lock, update->type, err)) { + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } + + if (!(update->flags & REF_ISPRUNING)) + delnames[delnum++] = update->lock->ref_name; } } - ret |= repack_without_refs(delnames, delnum, err); + if (repack_without_refs(delnames, delnum, err)) { + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } for (i = 0; i < delnum; i++) unlink_or_warn(git_path("logs/%s", delnames[i])); clear_loose_ref_cache(&ref_cache); cleanup: + transaction->state = REF_TRANSACTION_CLOSED; + for (i = 0; i < n; i++) if (updates[i]->lock) unlock_ref(updates[i]->lock); |