You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
171 lines
6.7 KiB
171 lines
6.7 KiB
From 7c39b498d6ea21b1c6f4d26b74c064ef2b507706 Mon Sep 17 00:00:00 2001 |
|
From: Lennart Poettering <lennart@poettering.net> |
|
Date: Mon, 13 Nov 2017 15:08:49 +0100 |
|
Subject: [PATCH] unit: rework a bit how we keep the service fdstore from being |
|
destroyed during service restart |
|
|
|
When preparing for a restart we quickly go through the DEAD/INACTIVE |
|
service state before entering AUTO_RESTART. When doing this, we need to |
|
make sure we don't destroy the FD store. Previously this was done by |
|
checking the failure state of the unit, and keeping the FD store around |
|
when the unit failed, under the assumption that the restart logic will |
|
then get into action. |
|
|
|
This is not entirely correct howver, as there might be failure states |
|
that will no result in restarts. |
|
|
|
With this commit we slightly alter the logic: a ref counter for the fd |
|
store is added, that is increased right before we handle the restart |
|
logic, and decreased again right-after. |
|
|
|
This should ensure that the fdstore lives exactly as long as it needs. |
|
|
|
Follow-up for f0bfbfac43b7faa68ef1bb2ad659c191b9ec85d2. |
|
|
|
(cherry picked from commit 7eb2a8a1259043e107ebec94e30ed160a93f40a7) |
|
(cherry picked from commit e2636bde0f07319d0d35262dac6ff2638ba4e598) |
|
(cherry picked from commit 20b18b7b9aac2532215dba4d56f19989a5fca9f0) |
|
Related: #1798162 |
|
--- |
|
src/core/service.c | 23 ++++++++++++++++++----- |
|
src/core/service.h | 1 + |
|
src/core/unit.c | 12 ++++-------- |
|
src/core/unit.h | 5 ++--- |
|
4 files changed, 25 insertions(+), 16 deletions(-) |
|
|
|
diff --git a/src/core/service.c b/src/core/service.c |
|
index ad45a38270..283c2968ea 100644 |
|
--- a/src/core/service.c |
|
+++ b/src/core/service.c |
|
@@ -265,6 +265,9 @@ static void service_fd_store_unlink(ServiceFDStore *fs) { |
|
static void service_release_fd_store(Service *s) { |
|
assert(s); |
|
|
|
+ if (s->n_keep_fd_store > 0) |
|
+ return; |
|
+ |
|
log_unit_debug(UNIT(s)->id, "Releasing all stored fds"); |
|
while (s->fd_store) |
|
service_fd_store_unlink(s->fd_store); |
|
@@ -272,7 +275,7 @@ static void service_release_fd_store(Service *s) { |
|
assert(s->n_fd_store == 0); |
|
} |
|
|
|
-static void service_release_resources(Unit *u, bool inactive) { |
|
+static void service_release_resources(Unit *u) { |
|
Service *s = SERVICE(u); |
|
|
|
assert(s); |
|
@@ -282,8 +285,7 @@ static void service_release_resources(Unit *u, bool inactive) { |
|
|
|
log_unit_debug(u->id, "Releasing resources."); |
|
|
|
- if (inactive) |
|
- service_release_fd_store(s); |
|
+ service_release_fd_store(s); |
|
} |
|
|
|
static void service_done(Unit *u) { |
|
@@ -331,7 +333,7 @@ static void service_done(Unit *u) { |
|
|
|
s->timer_event_source = sd_event_source_unref(s->timer_event_source); |
|
|
|
- service_release_resources(u, true); |
|
+ service_release_resources(u); |
|
} |
|
|
|
static int on_fd_store_io(sd_event_source *e, int fd, uint32_t revents, void *userdata) { |
|
@@ -1354,6 +1356,10 @@ static void service_enter_dead(Service *s, ServiceResult f, bool allow_restart) |
|
if (f != SERVICE_SUCCESS) |
|
s->result = f; |
|
|
|
+ /* Make sure service_release_resources() doesn't destroy our FD store, while we are changing through |
|
+ * SERVICE_FAILED/SERVICE_DEAD before entering into SERVICE_AUTO_RESTART. */ |
|
+ s->n_keep_fd_store++; |
|
+ |
|
service_set_state(s, s->result != SERVICE_SUCCESS ? SERVICE_FAILED : SERVICE_DEAD); |
|
|
|
if (s->result != SERVICE_SUCCESS) { |
|
@@ -1375,12 +1381,19 @@ static void service_enter_dead(Service *s, ServiceResult f, bool allow_restart) |
|
(!IN_SET(s->main_exec_status.code, CLD_KILLED, CLD_DUMPED) || !set_contains(s->restart_prevent_status.signal, INT_TO_PTR(s->main_exec_status.status)))) { |
|
|
|
r = service_arm_timer(s, s->restart_usec); |
|
- if (r < 0) |
|
+ if (r < 0) { |
|
+ s->n_keep_fd_store--; |
|
goto fail; |
|
+ } |
|
|
|
service_set_state(s, SERVICE_AUTO_RESTART); |
|
} |
|
|
|
+ /* The new state is in effect, let's decrease the fd store ref counter again. Let's also readd us to the GC |
|
+ * queue, so that the fd store is possibly gc'ed again */ |
|
+ s->n_keep_fd_store--; |
|
+ unit_add_to_gc_queue(UNIT(s)); |
|
+ |
|
s->forbid_restart = false; |
|
|
|
/* We want fresh tmpdirs in case service is started again immediately */ |
|
diff --git a/src/core/service.h b/src/core/service.h |
|
index e0547a464e..81b17db652 100644 |
|
--- a/src/core/service.h |
|
+++ b/src/core/service.h |
|
@@ -214,6 +214,7 @@ struct Service { |
|
ServiceFDStore *fd_store; |
|
unsigned n_fd_store; |
|
unsigned n_fd_store_max; |
|
+ unsigned n_keep_fd_store; |
|
}; |
|
|
|
extern const UnitVTable service_vtable; |
|
diff --git a/src/core/unit.c b/src/core/unit.c |
|
index 33e0b7126b..e74c6bc2cc 100644 |
|
--- a/src/core/unit.c |
|
+++ b/src/core/unit.c |
|
@@ -284,7 +284,6 @@ int unit_set_description(Unit *u, const char *description) { |
|
|
|
bool unit_may_gc(Unit *u) { |
|
UnitActiveState state; |
|
- bool inactive; |
|
assert(u); |
|
|
|
/* Checks whether the unit is ready to be unloaded for garbage collection. |
|
@@ -302,17 +301,14 @@ bool unit_may_gc(Unit *u) { |
|
return false; |
|
|
|
state = unit_active_state(u); |
|
- inactive = state == UNIT_INACTIVE; |
|
|
|
- /* If the unit is inactive and failed and no job is queued for |
|
- * it, then release its runtime resources */ |
|
+ /* If the unit is inactive and failed and no job is queued for it, then release its runtime resources */ |
|
if (UNIT_IS_INACTIVE_OR_FAILED(state) && |
|
UNIT_VTABLE(u)->release_resources) |
|
- UNIT_VTABLE(u)->release_resources(u, inactive); |
|
+ UNIT_VTABLE(u)->release_resources(u); |
|
|
|
- /* But we keep the unit object around for longer when it is |
|
- * referenced or configured to not be gc'ed */ |
|
- if (!inactive) |
|
+ /* But we keep the unit object around for longer when it is referenced or configured to not be gc'ed */ |
|
+ if (state != UNIT_INACTIVE) |
|
return false; |
|
|
|
if (UNIT_VTABLE(u)->no_gc) |
|
diff --git a/src/core/unit.h b/src/core/unit.h |
|
index 97a63f0f8b..61ff59e8c7 100644 |
|
--- a/src/core/unit.h |
|
+++ b/src/core/unit.h |
|
@@ -357,9 +357,8 @@ struct UnitVTable { |
|
* even though nothing references it and it isn't active in any way. */ |
|
bool (*may_gc)(Unit *u); |
|
|
|
- /* When the unit is not running and no job for it queued we |
|
- * shall release its runtime resources */ |
|
- void (*release_resources)(Unit *u, bool inactive); |
|
+ /* When the unit is not running and no job for it queued we shall release its runtime resources */ |
|
+ void (*release_resources)(Unit *u); |
|
|
|
/* Return true when this unit is suitable for snapshotting */ |
|
bool (*check_snapshot)(Unit *u);
|
|
|