*/
#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
* 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
}
/*
- * Return true iff a reference named refname could be created without
- * conflicting with the name of an existing reference in dir. 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
+ * 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
*
* extras and skip must be sorted.
*/
-static int is_refname_available(const char *refname,
- const struct string_list *extras,
- 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;
int pos;
struct strbuf dirname = STRBUF_INIT;
- int ret = 0;
+ 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: */
* a proper prefix of refname; e.g.,
* "refs/foo", and is not in skip.
*/
- error("'%s' exists; cannot create '%s'",
- dirname.buf, refname);
+ 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))) {
- error("cannot process '%s' and '%s' at the same time",
- refname, dirname.buf);
+ strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
+ refname, dirname.buf);
goto cleanup;
}
dir = get_ref_dir(dir->entries[pos]);
sort_ref_dir(dir);
if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) {
- error("'%s' exists; cannot create '%s'",
- data.conflicting_refname, refname);
+ strbuf_addf(err, "'%s' exists; cannot create '%s'",
+ data.conflicting_refname, refname);
goto cleanup;
}
}
break;
if (!skip || !string_list_has_string(skip, extra_refname)) {
- error("cannot process '%s' and '%s' at the same time",
- refname, extra_refname);
+ strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
+ refname, extra_refname);
goto cleanup;
}
}
}
/* No conflicts were found */
- ret = 1;
+ ret = 0;
cleanup:
strbuf_release(&dirname);
const unsigned char *old_sha1,
const struct string_list *extras,
const struct string_list *skip,
- unsigned int flags, int *type_p)
+ unsigned int flags, int *type_p,
+ struct strbuf *err)
{
char *ref_file;
const char *orig_refname = refname;
int resolve_flags = 0;
int attempts_remaining = 3;
+ assert(err);
+
lock = xcalloc(1, sizeof(struct ref_lock));
lock->lock_fd = -1;
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,
*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;
}
/*
* our refname.
*/
if (is_null_sha1(lock->old_sha1) &&
- !is_refname_available(refname, extras, skip, get_packed_refs(&ref_cache))) {
+ verify_refname_available(refname, extras, skip,
+ get_packed_refs(&ref_cache), err)) {
last_errno = ENOTDIR;
goto error_return;
}
/* 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;
}
*/
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;
}
}
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, NULL, &skip, get_packed_refs(&ref_cache))
- && is_refname_available(newname, NULL, &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)
{
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);
logmoved = log;
- lock = lock_ref_sha1_basic(newrefname, NULL, 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;
}
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;
}
return 0;
rollback:
- lock = lock_ref_sha1_basic(oldrefname, NULL, 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;
}
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;
}
/*
- * 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;
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) &&
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];
- unsigned int flags = update->flags;
- if ((flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1))
- flags |= REF_DELETING;
+ 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,
- flags,
- &update->type);
+ 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;
}
- }
-
- /* Perform updates first so live commits remain referenced */
- for (i = 0; i < n; i++) {
- struct ref_update *update = updates[i];
- int flags = update->flags;
-
- if ((flags & REF_HAVE_NEW) && !is_null_sha1(update->new_sha1)) {
+ 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)) {
+ 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.
*/
- unlock_ref(update->lock);
+ } 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 (update->flags & REF_NEEDS_COMMIT) {
+ if (commit_ref_update(update->lock,
+ update->new_sha1, update->msg)) {
+ /* freed by commit_ref_update(): */
update->lock = NULL;
- } else 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;
} else {
- /* freed by write_ref_sha1(): */
+ /* freed by commit_ref_update(): */
update->lock = NULL;
}
}
/* Perform deletes now that updates are safely completed */
for (i = 0; i < n; i++) {
struct ref_update *update = updates[i];
- int flags = update->flags;
- if ((flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1)) {
+ if (update->flags & REF_DELETING) {
if (delete_ref_loose(update->lock, update->type, err)) {
ret = TRANSACTION_GENERIC_ERROR;
goto cleanup;
}
- if (!(flags & REF_ISPRUNING))
+ if (!(update->flags & REF_ISPRUNING))
string_list_append(&refs_to_delete,
update->lock->ref_name);
}
char *log_file;
int status = 0;
int type;
+ struct strbuf err = STRBUF_INIT;
memset(&cb, 0, sizeof(cb));
cb.flags = flags;
* 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);
- if (!lock)
- return error("cannot lock ref '%s'", refname);
+ 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;