diff options
| -rw-r--r-- | src/core/scope.c | 2 | ||||
| -rw-r--r-- | src/core/service.c | 2 | ||||
| -rw-r--r-- | src/shared/serialize.c | 43 |
3 files changed, 39 insertions, 8 deletions
diff --git a/src/core/scope.c b/src/core/scope.c index 14d6c1f6a4..cfa2aeb03f 100644 --- a/src/core/scope.c +++ b/src/core/scope.c @@ -571,6 +571,8 @@ static int scope_deserialize_item(Unit *u, const char *key, const char *value, F } else if (streq(key, "pids")) { _cleanup_(pidref_done) PidRef pidref = PIDREF_NULL; + /* We don't check if we already received the pid before here because unit_watch_pidref() + * does this check internally and discards the new pidref if we already received it before. */ if (deserialize_pidref(fds, value, &pidref) >= 0) { r = unit_watch_pidref(u, &pidref, /* exclusive= */ false); if (r < 0) diff --git a/src/core/service.c b/src/core/service.c index 6d0281fcd7..f6800c3170 100644 --- a/src/core/service.c +++ b/src/core/service.c @@ -3184,7 +3184,7 @@ static int service_deserialize_item(Unit *u, const char *key, const char *value, } else if (streq(key, "main-pid")) { PidRef pidref; - if (deserialize_pidref(fds, value, &pidref) >= 0) + if (!pidref_is_set(&s->main_pid) && deserialize_pidref(fds, value, &pidref) >= 0) (void) service_set_main_pidref(s, pidref); } else if (streq(key, "main-pid-known")) { diff --git a/src/shared/serialize.c b/src/shared/serialize.c index d1f41ce4c8..735caf4978 100644 --- a/src/shared/serialize.c +++ b/src/shared/serialize.c @@ -188,18 +188,20 @@ int serialize_pidref(FILE *f, FDSet *fds, const char *key, PidRef *pidref) { if (!pidref_is_set(pidref)) return 0; - /* We always serialize the pid, to keep downgrades mostly working (older versions will deserialize - * the pid and silently fail to deserialize the pidfd). If we also have a pidfd, we serialize it - * first and encode the fd number prefixed by "@" in the serialization. */ + /* We always serialize the pid separately, to keep downgrades mostly working (older versions will + * deserialize the pid and silently fail to deserialize the pidfd). If we also have a pidfd, we + * serialize both the pid and pidfd, so that we can construct the exact same pidref after + * deserialization (this doesn't work with only the pidfd, as we can't retrieve the original pid + * from the pidfd anymore if the process is reaped). */ if (pidref->fd >= 0) { int copy = fdset_put_dup(fds, pidref->fd); if (copy < 0) return log_error_errno(copy, "Failed to add file descriptor to serialization set: %m"); - r = serialize_item_format(f, key, "@%i", copy); + r = serialize_item_format(f, key, "@%i:" PID_FMT, copy, pidref->pid); if (r < 0) - return log_error_errno(r, "Failed to serialize PID file descriptor: %m"); + return r; } return serialize_item_format(f, key, PID_FMT, pidref->pid); @@ -480,12 +482,39 @@ int deserialize_pidref(FDSet *fds, const char *value, PidRef *ret) { e = startswith(value, "@"); if (e) { - int fd = deserialize_fd(fds, e); + _cleanup_free_ char *fdstr = NULL, *pidstr = NULL; + _cleanup_close_ int fd = -EBADF; + + r = extract_many_words(&e, ":", /* flags = */ 0, &fdstr, &pidstr); + if (r < 0) + return log_debug_errno(r, "Failed to deserialize pidref '%s': %m", e); + if (r == 0) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot deserialize pidref from empty string."); + + assert(r <= 2); + fd = deserialize_fd(fds, fdstr); if (fd < 0) return fd; - r = pidref_set_pidfd_consume(ret, fd); + /* The serialization format changed after 255.4. In systemd <= 255.4 only pidfd is + * serialized, but that causes problems when reconstructing pidref (see serialize_pidref for + * details). After 255.4 the pid is serialized as well even if we have a pidfd, but we still + * need to support older format as we might be upgrading from a version that still uses the + * old format. */ + if (pidstr) { + pid_t pid; + + r = parse_pid(pidstr, &pid); + if (r < 0) + return log_debug_errno(r, "Failed to parse PID: %s", pidstr); + + *ret = (PidRef) { + .pid = pid, + .fd = TAKE_FD(fd), + }; + } else + r = pidref_set_pidfd_consume(ret, TAKE_FD(fd)); } else { pid_t pid; |