From b17c9620c87a1d8117da72b30a2e096df02a2bb5 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 10 Dec 2018 19:40:37 +0100
Subject: [PATCH] core: rework how we deserialize jobs

Let's add a helper call unit_deserialize_job() for this purpose, and
let's move registration in the global jobs hash table into
job_install_deserialized() so that it it is done after all superficial
checks are done, and before transitioning into installed states, so that
rollback code is not necessary anymore.
---
 src/core/job.c  | 16 +++++++++++-----
 src/core/job.h  |  2 ++
 src/core/unit.c | 52 +++++++++++++++++++++++++++-------------------------
 3 files changed, 40 insertions(+), 30 deletions(-)

diff --git a/src/core/job.c b/src/core/job.c
index 8106a78..f635b7e 100644
--- a/src/core/job.c
+++ b/src/core/job.c
@@ -244,19 +244,25 @@ Job* job_install(Job *j) {
 
 int job_install_deserialized(Job *j) {
         Job **pj;
+        int r;
 
         assert(!j->installed);
 
         if (j->type < 0 || j->type >= _JOB_TYPE_MAX_IN_TRANSACTION)
-                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                return log_unit_debug_errno(j->unit, SYNTHETIC_ERRNO(EINVAL),
                                        "Invalid job type %s in deserialization.",
                                        strna(job_type_to_string(j->type)));
 
         pj = (j->type == JOB_NOP) ? &j->unit->nop_job : &j->unit->job;
-        if (*pj) {
-                log_unit_debug(j->unit, "Unit already has a job installed. Not installing deserialized job.");
-                return -EEXIST;
-        }
+        if (*pj)
+                return log_unit_debug_errno(j->unit, SYNTHETIC_ERRNO(EEXIST),
+                                            "Unit already has a job installed. Not installing deserialized job.");
+
+        r = hashmap_put(j->manager->jobs, UINT32_TO_PTR(j->id), j);
+        if (r == -EEXIST)
+                return log_unit_debug_errno(j->unit, r, "Job ID %" PRIu32 " already used, cannot deserialize job.", j->id);
+        if (r < 0)
+                return log_unit_debug_errno(j->unit, r, "Failed to insert job into jobs hash table: %m");
 
         *pj = j;
         j->installed = true;
diff --git a/src/core/job.h b/src/core/job.h
index 649f812..1b9bcdd 100644
--- a/src/core/job.h
+++ b/src/core/job.h
@@ -222,6 +222,8 @@ void job_add_to_gc_queue(Job *j);
 int job_get_before(Job *j, Job*** ret);
 int job_get_after(Job *j, Job*** ret);
 
+DEFINE_TRIVIAL_CLEANUP_FUNC(Job*, job_free);
+
 const char* job_type_to_string(JobType t) _const_;
 JobType job_type_from_string(const char *s) _pure_;
 
diff --git a/src/core/unit.c b/src/core/unit.c
index a9303a0..ac8f403 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -3288,6 +3288,29 @@ int unit_serialize(Unit *u, FILE *f, FDSet *fds, bool serialize_jobs) {
         return 0;
 }
 
+static int unit_deserialize_job(Unit *u, FILE *f) {
+        _cleanup_(job_freep) Job *j = NULL;
+        int r;
+
+        assert(u);
+        assert(f);
+
+        j = job_new_raw(u);
+        if (!j)
+                return log_oom();
+
+        r = job_deserialize(j, f);
+        if (r < 0)
+                return r;
+
+        r = job_install_deserialized(j);
+        if (r < 0)
+                return r;
+
+        TAKE_PTR(j);
+        return 0;
+}
+
 int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
         int r;
 
@@ -3321,32 +3344,11 @@ int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
 
                 if (streq(l, "job")) {
                         if (v[0] == '\0') {
-                                /* new-style serialized job */
-                                Job *j;
-
-                                j = job_new_raw(u);
-                                if (!j)
-                                        return log_oom();
-
-                                r = job_deserialize(j, f);
-                                if (r < 0) {
-                                        job_free(j);
-                                        return r;
-                                }
-
-                                r = hashmap_put(u->manager->jobs, UINT32_TO_PTR(j->id), j);
-                                if (r < 0) {
-                                        job_free(j);
-                                        return r;
-                                }
-
-                                r = job_install_deserialized(j);
-                                if (r < 0) {
-                                        hashmap_remove(u->manager->jobs, UINT32_TO_PTR(j->id));
-                                        job_free(j);
+                                /* New-style serialized job */
+                                r = unit_deserialize_job(u, f);
+                                if (r < 0)
                                         return r;
-                                }
-                        } else  /* legacy for pre-44 */
+                        } else  /* Legacy for pre-44 */
                                 log_unit_warning(u, "Update from too old systemd versions are unsupported, cannot deserialize job: %s", v);
                         continue;
                 } else if (streq(l, "state-change-timestamp")) {
-- 
2.7.4