in a <citerefentry><refentrytitle>memfd_create</refentrytitle><manvolnum>2</manvolnum></citerefentry> memory
file descriptor. Note that the service manager will accept messages for a service only if its
<varname>FileDescriptorStoreMax=</varname> setting is non-zero (defaults to zero, see
- <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>). If file
- descriptors sent are pollable (see
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>). If
+ <varname>FDPOLL=0</varname> is not set and the file descriptors sent are pollable (see
<citerefentry><refentrytitle>epoll_ctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>), then any
<constant>EPOLLHUP</constant> or <constant>EPOLLERR</constant> event seen on them will result in their
automatic removal from the store. Multiple arrays of file descriptors may be sent in separate messages, in
submitted name does not follow these restrictions, it is ignored.</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term>FDPOLL=0</term>
+
+ <listitem><para>When used in combination with <varname>FDSTORE=1</varname>, disables polling of the stored
+ file descriptors regardless of whether or not they are pollable. As this option disables automatic cleanup
+ of the stored file descriptors on EPOLLERR and EPOLLHUP, care must be taken to ensure proper manual cleanup.
+ Use of this option is not generally recommended except for when automatic cleanup has unwanted behavior such
+ as prematurely discarding file descriptors from the store.</para></listitem>
+ </varlistentry>
+
</variablelist>
<para>It is recommended to prefix variable names that are not
return 0;
}
-static int service_add_fd_store(Service *s, int fd, const char *name) {
+static int service_add_fd_store(Service *s, int fd, const char *name, bool do_poll) {
ServiceFDStore *fs;
int r;
fs->fd = fd;
fs->service = s;
+ fs->do_poll = do_poll;
fs->fdname = strdup(name ?: "stored");
if (!fs->fdname) {
free(fs);
return -ENOMEM;
}
- r = sd_event_add_io(UNIT(s)->manager->event, &fs->event_source, fd, 0, on_fd_store_io, fs);
- if (r < 0 && r != -EPERM) { /* EPERM indicates fds that aren't pollable, which is OK */
- free(fs->fdname);
- free(fs);
- return r;
- } else if (r >= 0)
- (void) sd_event_source_set_description(fs->event_source, "service-fd-store");
+ if (do_poll) {
+ r = sd_event_add_io(UNIT(s)->manager->event, &fs->event_source, fd, 0, on_fd_store_io, fs);
+ if (r < 0 && r != -EPERM) { /* EPERM indicates fds that aren't pollable, which is OK */
+ free(fs->fdname);
+ free(fs);
+ return r;
+ } else if (r >= 0)
+ (void) sd_event_source_set_description(fs->event_source, "service-fd-store");
+ }
LIST_PREPEND(fd_store, s->fd_store, fs);
s->n_fd_store++;
return 1; /* fd newly stored */
}
-static int service_add_fd_store_set(Service *s, FDSet *fds, const char *name) {
+static int service_add_fd_store_set(Service *s, FDSet *fds, const char *name, bool do_poll) {
int r;
assert(s);
if (fd < 0)
break;
- r = service_add_fd_store(s, fd, name);
+ r = service_add_fd_store(s, fd, name, do_poll);
if (r == -EXFULL)
return log_unit_warning_errno(UNIT(s), r,
"Cannot store more fds than FileDescriptorStoreMax=%u, closing remaining.",
if (!c)
return log_oom();
- (void) serialize_item_format(f, "fd-store-fd", "%i %s", copy, c);
+ (void) serialize_item_format(f, "fd-store-fd", "%i \"%s\" %i", copy, c, fs->do_poll);
}
if (s->main_exec_status.pid > 0) {
s->socket_fd = fdset_remove(fds, fd);
}
} else if (streq(key, "fd-store-fd")) {
- const char *fdv;
- size_t pf;
+ _cleanup_free_ char *fdv = NULL, *fdn = NULL, *fdp = NULL;
int fd;
+ int do_poll;
- pf = strcspn(value, WHITESPACE);
- fdv = strndupa(value, pf);
-
- if (safe_atoi(fdv, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
+ r = extract_first_word(&value, &fdv, NULL, 0);
+ if (r <= 0 || safe_atoi(fdv, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd)) {
log_unit_debug(u, "Failed to parse fd-store-fd value: %s", value);
- else {
- _cleanup_free_ char *t = NULL;
- const char *fdn;
+ return 0;
+ }
- fdn = value + pf;
- fdn += strspn(fdn, WHITESPACE);
- (void) cunescape(fdn, 0, &t);
+ r = extract_first_word(&value, &fdn, NULL, EXTRACT_CUNESCAPE | EXTRACT_UNQUOTE);
+ if (r <= 0) {
+ log_unit_debug_errno(u, r, "Failed to parse fd-store-fd value \"%s\": %m", value);
+ return 0;
+ }
- r = service_add_fd_store(s, fd, t);
- if (r < 0)
- log_unit_error_errno(u, r, "Failed to add fd to store: %m");
- else
- fdset_remove(fds, fd);
+ r = extract_first_word(&value, &fdp, NULL, 0);
+ if (r == 0) {
+ /* If the value is not present, we assume the default */
+ do_poll = 1;
+ } else if (r < 0 || safe_atoi(fdp, &do_poll) < 0) {
+ log_unit_debug_errno(u, r, "Failed to parse fd-store-fd value \"%s\": %m", value);
+ return 0;
}
+ r = service_add_fd_store(s, fd, fdn, do_poll);
+ if (r < 0)
+ log_unit_error_errno(u, r, "Failed to add fd to store: %m");
+ else
+ fdset_remove(fds, fd);
} else if (streq(key, "main-exec-status-pid")) {
pid_t pid;
name = NULL;
}
- (void) service_add_fd_store_set(s, fds, name);
+ (void) service_add_fd_store_set(s, fds, name, !strv_contains(tags, "FDPOLL=0"));
}
/* Notify clients about changed status or main pid */