event: be more conservative when returning errors from event handler callbacks

We really should return errors from event handlers if we have a
continous problem and don't know any other solution.

6 files changed, 42 insertions, 60 deletions

diff --git a/src/core/manager.c b/src/core/manager.c
index ad4c6e8ed9..a2f3570bb6 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -1631,7 +1631,7 @@ static int manager_dispatch_signal_fd(sd_event_source *source, int fd, uint32_t
         }
 
         if (sigchld)
-                return manager_dispatch_sigchld(m);
+                manager_dispatch_sigchld(m);
 
         return 0;
 }
diff --git a/src/journal/journald-stream.c b/src/journal/journald-stream.c
index 8958c7f3de..aba9054b27 100644
--- a/src/journal/journald-stream.c
+++ b/src/journal/journald-stream.c
@@ -293,7 +293,6 @@ static int stdout_stream_process(sd_event_source *es, int fd, uint32_t revents,
 
         if ((revents|EPOLLIN|EPOLLHUP) != (EPOLLIN|EPOLLHUP)) {
                 log_error("Got invalid event from epoll for stdout stream: %"PRIx32, revents);
-                r = -EIO;
                 goto terminate;
         }
 
@@ -304,12 +303,11 @@ static int stdout_stream_process(sd_event_source *es, int fd, uint32_t revents,
                         return 0;
 
                 log_warning("Failed to read from stream: %m");
-                r = -errno;
                 goto terminate;
         }
 
         if (l == 0) {
-                r = stdout_stream_scan(s, true);
+                stdout_stream_scan(s, true);
                 goto terminate;
         }
 
@@ -391,7 +389,6 @@ static int stdout_stream_new(sd_event_source *es, int listen_fd, uint32_t revent
         len = sizeof(stream->ucred);
         if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &stream->ucred, &len) < 0) {
                 log_error("Failed to determine peer credentials: %m");
-                r = -errno;
                 goto fail;
         }
 
@@ -404,7 +401,6 @@ static int stdout_stream_new(sd_event_source *es, int listen_fd, uint32_t revent
 
         if (shutdown(fd, SHUT_WR) < 0) {
                 log_error("Failed to shutdown writing side of socket: %m");
-                r = -errno;
                 goto fail;
         }
 
@@ -428,7 +424,7 @@ static int stdout_stream_new(sd_event_source *es, int listen_fd, uint32_t revent
 
 fail:
         stdout_stream_free(stream);
-        return r;
+        return 0;
 }
 
 int server_open_stdout_socket(Server *s) {
diff --git a/src/login/logind-button.c b/src/login/logind-button.c
index 3dd0829486..e29f2c4c5f 100644
--- a/src/login/logind-button.c
+++ b/src/login/logind-button.c
@@ -141,7 +141,9 @@ static int button_dispatch(sd_event_source *s, int fd, uint32_t revents, void *u
                                    "MESSAGE=Power key pressed.",
                                    MESSAGE_ID(SD_MESSAGE_POWER_KEY),
                                    NULL);
-                        return button_handle(b, INHIBIT_HANDLE_POWER_KEY, b->manager->handle_power_key, b->manager->power_key_ignore_inhibited, true);
+
+                        button_handle(b, INHIBIT_HANDLE_POWER_KEY, b->manager->handle_power_key, b->manager->power_key_ignore_inhibited, true);
+                        break;
 
                 /* The kernel is a bit confused here:
 
@@ -154,41 +156,41 @@ static int button_dispatch(sd_event_source *s, int fd, uint32_t revents, void *u
                                    "MESSAGE=Suspend key pressed.",
                                    MESSAGE_ID(SD_MESSAGE_SUSPEND_KEY),
                                    NULL);
-                        return button_handle(b, INHIBIT_HANDLE_SUSPEND_KEY, b->manager->handle_suspend_key, b->manager->suspend_key_ignore_inhibited, true);
+
+                        button_handle(b, INHIBIT_HANDLE_SUSPEND_KEY, b->manager->handle_suspend_key, b->manager->suspend_key_ignore_inhibited, true);
+                        break;
 
                 case KEY_SUSPEND:
                         log_struct(LOG_INFO,
                                    "MESSAGE=Hibernate key pressed.",
                                    MESSAGE_ID(SD_MESSAGE_HIBERNATE_KEY),
                                    NULL);
-                        return button_handle(b, INHIBIT_HANDLE_HIBERNATE_KEY, b->manager->handle_hibernate_key, b->manager->hibernate_key_ignore_inhibited, true);
+
+                        button_handle(b, INHIBIT_HANDLE_HIBERNATE_KEY, b->manager->handle_hibernate_key, b->manager->hibernate_key_ignore_inhibited, true);
+                        break;
                 }
 
         } else if (ev.type == EV_SW && ev.value > 0) {
 
-                switch (ev.code) {
-
-                case SW_LID:
+                if (ev.code == SW_LID) {
                         log_struct(LOG_INFO,
                                    "MESSAGE=Lid closed.",
                                    MESSAGE_ID(SD_MESSAGE_LID_CLOSED),
                                    NULL);
-                        b->lid_close_queued = true;
 
-                        return button_handle(b, INHIBIT_HANDLE_LID_SWITCH, b->manager->handle_lid_switch, b->manager->lid_switch_ignore_inhibited, true);
+                        b->lid_close_queued = true;
+                        button_handle(b, INHIBIT_HANDLE_LID_SWITCH, b->manager->handle_lid_switch, b->manager->lid_switch_ignore_inhibited, true);
                 }
 
         } else if (ev.type == EV_SW && ev.value == 0) {
 
-                switch (ev.code) {
-
-                case SW_LID:
+                if (ev.code == SW_LID) {
                         log_struct(LOG_INFO,
                                    "MESSAGE=Lid opened.",
                                    MESSAGE_ID(SD_MESSAGE_LID_OPENED),
                                    NULL);
+
                         b->lid_close_queued = false;
-                        break;
                 }
         }
 
diff --git a/src/login/logind.c b/src/login/logind.c
index 222608743e..b7c8f71a52 100644
--- a/src/login/logind.c
+++ b/src/login/logind.c
@@ -34,6 +34,7 @@
 #include "bus-util.h"
 #include "bus-error.h"
 #include "logind.h"
+#include "udev-util.h"
 
 Manager *manager_new(void) {
         Manager *m;
@@ -490,9 +491,8 @@ static int manager_enumerate_inhibitors(Manager *m) {
 }
 
 static int manager_dispatch_seat_udev(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        _cleanup_udev_device_unref_ struct udev_device *d = NULL;
         Manager *m = userdata;
-        struct udev_device *d;
-        int r;
 
         assert(m);
 
@@ -500,16 +500,13 @@ static int manager_dispatch_seat_udev(sd_event_source *s, int fd, uint32_t reven
         if (!d)
                 return -ENOMEM;
 
-        r = manager_process_seat_device(m, d);
-        udev_device_unref(d);
-
-        return r;
+        manager_process_seat_device(m, d);
+        return 0;
 }
 
 static int manager_dispatch_device_udev(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        _cleanup_udev_device_unref_ struct udev_device *d = NULL;
         Manager *m = userdata;
-        struct udev_device *d;
-        int r;
 
         assert(m);
 
@@ -517,16 +514,13 @@ static int manager_dispatch_device_udev(sd_event_source *s, int fd, uint32_t rev
         if (!d)
                 return -ENOMEM;
 
-        r = manager_process_seat_device(m, d);
-        udev_device_unref(d);
-
-        return r;
+        manager_process_seat_device(m, d);
+        return 0;
 }
 
 static int manager_dispatch_vcsa_udev(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        _cleanup_udev_device_unref_ struct udev_device *d = NULL;
         Manager *m = userdata;
-        struct udev_device *d;
-        int r = 0;
         const char *name;
 
         assert(m);
@@ -541,17 +535,14 @@ static int manager_dispatch_vcsa_udev(sd_event_source *s, int fd, uint32_t reven
          * VTs, to make sure our auto VTs never go away. */
 
         if (name && startswith(name, "vcsa") && streq_ptr(udev_device_get_action(d), "remove"))
-                r = seat_preallocate_vts(m->seat0);
+                seat_preallocate_vts(m->seat0);
 
-        udev_device_unref(d);
-
-        return r;
+        return 0;
 }
 
 static int manager_dispatch_button_udev(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        _cleanup_udev_device_unref_ struct udev_device *d = NULL;
         Manager *m = userdata;
-        struct udev_device *d;
-        int r;
 
         assert(m);
 
@@ -559,10 +550,8 @@ static int manager_dispatch_button_udev(sd_event_source *s, int fd, uint32_t rev
         if (!d)
                 return -ENOMEM;
 
-        r = manager_process_button_device(m, d);
-        udev_device_unref(d);
-
-        return r;
+        manager_process_button_device(m, d);
+        return 0;
 }
 
 static int manager_dispatch_console(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
@@ -573,7 +562,6 @@ static int manager_dispatch_console(sd_event_source *s, int fd, uint32_t revents
         assert(m->console_active_fd == fd);
 
         seat_read_active_vt(m->seat0);
-
         return 0;
 }
 
diff --git a/src/network/networkd-manager.c b/src/network/networkd-manager.c
index d59b9139a3..1b5837e42c 100644
--- a/src/network/networkd-manager.c
+++ b/src/network/networkd-manager.c
@@ -22,6 +22,7 @@
 #include "path-util.h"
 #include "networkd.h"
 #include "libudev-private.h"
+#include "udev-util.h"
 
 int manager_new(Manager **ret) {
         _cleanup_manager_free_ Manager *m = NULL;
@@ -204,19 +205,13 @@ finish:
 static int manager_dispatch_link_udev(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
         Manager *m = userdata;
         struct udev_monitor *monitor = m->udev_monitor;
-        struct udev_device *device;
-        int r;
+        _cleanup_udev_device_unref_ struct udev_device *device = NULL;
 
         device = udev_monitor_receive_device(monitor);
         if (!device)
                 return -ENOMEM;
 
-        r = manager_process_link(m, device);
-        if (r < 0)
-                return r;
-
-        udev_device_unref(device);
-
+        manager_process_link(m, device);
         return 0;
 }
 
diff --git a/src/socket-proxy/socket-proxyd.c b/src/socket-proxy/socket-proxyd.c
index c6f56be60a..b066633b1d 100644
--- a/src/socket-proxy/socket-proxyd.c
+++ b/src/socket-proxy/socket-proxyd.c
@@ -462,6 +462,7 @@ fail:
 }
 
 static int accept_cb(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        _cleanup_free_ char *peer = NULL;
         Context *context = userdata;
         int nfd = -1, r;
 
@@ -471,24 +472,24 @@ static int accept_cb(sd_event_source *s, int fd, uint32_t revents, void *userdat
         assert(context);
 
         nfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
-        if (nfd >= 0) {
-                _cleanup_free_ char *peer = NULL;
-
+        if (nfd < 0) {
+                if (errno != -EAGAIN)
+                        log_warning("Failed to accept() socket: %m");
+        } else {
                 getpeername_pretty(nfd, &peer);
                 log_debug("New connection from %s", strna(peer));
 
                 r = add_connection_socket(context, sd_event_source_get_event(s), nfd);
                 if (r < 0) {
+                        log_error("Failed to accept connection, ignoring: %s", strerror(-r));
                         close_nointr_nofail(fd);
-                        return r;
                 }
-
-        } else if (errno != -EAGAIN)
-                log_warning("Failed to accept() socket: %m");
+        }
 
         r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT);
         if (r < 0) {
-                log_error("Error %d while re-enabling listener with ONESHOT: %s", r, strerror(-r));
+                log_error("Error while re-enabling listener with ONESHOT: %s", strerror(-r));
+                sd_event_exit(sd_event_source_get_event(s), r);
                 return r;
         }