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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 13:00:47 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 13:00:47 +0000
commit2cb7e0aaedad73b076ea18c6900b0e86c5760d79 (patch)
treeda68ca54bb79f4080079bf0828acda937593a4e1 /src/journal/journald-context.c
parentInitial commit. (diff)
downloadsystemd-2cb7e0aaedad73b076ea18c6900b0e86c5760d79.tar.xz
systemd-2cb7e0aaedad73b076ea18c6900b0e86c5760d79.zip
Adding upstream version 247.3.upstream/247.3upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/journal/journald-context.c')
-rw-r--r--src/journal/journald-context.c792
1 files changed, 792 insertions, 0 deletions
diff --git a/src/journal/journald-context.c b/src/journal/journald-context.c
new file mode 100644
index 0000000..8736495
--- /dev/null
+++ b/src/journal/journald-context.c
@@ -0,0 +1,792 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#if HAVE_SELINUX
+#include <selinux/selinux.h>
+#endif
+
+#include "alloc-util.h"
+#include "audit-util.h"
+#include "cgroup-util.h"
+#include "env-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "io-util.h"
+#include "journal-util.h"
+#include "journald-context.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "procfs-util.h"
+#include "string-util.h"
+#include "syslog-util.h"
+#include "unaligned.h"
+#include "user-util.h"
+
+/* This implements a metadata cache for clients, which are identified by their PID. Requesting metadata through /proc
+ * is expensive, hence let's cache the data if we can. Note that this means the metadata might be out-of-date when we
+ * store it, but it might already be anyway, as we request the data asynchronously from /proc at a different time the
+ * log entry was originally created. We hence just increase the "window of inaccuracy" a bit.
+ *
+ * The cache is indexed by the PID. Entries may be "pinned" in the cache, in which case the entries are not removed
+ * until they are unpinned. Unpinned entries are kept around until cache pressure is seen. Cache entries older than 5s
+ * are never used (a sad attempt to deal with the UNIX weakness of PIDs reuse), cache entries older than 1s are
+ * refreshed in an incremental way (meaning: data is reread from /proc, but any old data we can't refresh is not
+ * flushed out). Data newer than 1s is used immediately without refresh.
+ *
+ * Log stream clients (i.e. all clients using the AF_UNIX/SOCK_STREAM stdout/stderr transport) will pin a cache entry
+ * as long as their socket is connected. Note that cache entries are shared between different transports. That means a
+ * cache entry pinned for the stream connection logic may be reused for the syslog or native protocols.
+ *
+ * Caching metadata like this has two major benefits:
+ *
+ * 1. Reading metadata is expensive, and we can thus substantially speed up log processing under flood.
+ *
+ * 2. Because metadata caching is shared between stream and datagram transports and stream connections pin a cache
+ * entry there's a good chance we can properly map a substantial set of datagram log messages to their originating
+ * service, as all services (unless explicitly configured otherwise) will have their stdout/stderr connected to a
+ * stream connection. This should improve cases where a service process logs immediately before exiting and we
+ * previously had trouble associating the log message with the service.
+ *
+ * NB: With and without the metadata cache: the implicitly added entry metadata in the journal (with the exception of
+ * UID/PID/GID and SELinux label) must be understood as possibly slightly out of sync (i.e. sometimes slightly older
+ * and sometimes slightly newer than what was current at the log event).
+ */
+
+/* We refresh every 1s */
+#define REFRESH_USEC (1*USEC_PER_SEC)
+
+/* Data older than 5s we flush out */
+#define MAX_USEC (5*USEC_PER_SEC)
+
+/* Keep at most 16K entries in the cache. (Note though that this limit may be violated if enough streams pin entries in
+ * the cache, in which case we *do* permit this limit to be breached. That's safe however, as the number of stream
+ * clients itself is limited.) */
+#define CACHE_MAX_FALLBACK 128U
+#define CACHE_MAX_MAX (16*1024U)
+#define CACHE_MAX_MIN 64U
+
+static size_t cache_max(void) {
+ static size_t cached = -1;
+
+ if (cached == (size_t) -1) {
+ uint64_t mem_total;
+ int r;
+
+ r = procfs_memory_get(&mem_total, NULL);
+ if (r < 0) {
+ log_warning_errno(r, "Cannot query /proc/meminfo for MemTotal: %m");
+ cached = CACHE_MAX_FALLBACK;
+ } else
+ /* Cache entries are usually a few kB, but the process cmdline is controlled by the
+ * user and can be up to _SC_ARG_MAX, usually 2MB. Let's say that approximately up to
+ * 1/8th of memory may be used by the cache.
+ *
+ * In the common case, this formula gives 64 cache entries for each GB of RAM.
+ */
+ cached = CLAMP(mem_total / 8 / sc_arg_max(), CACHE_MAX_MIN, CACHE_MAX_MAX);
+ }
+
+ return cached;
+}
+
+static int client_context_compare(const void *a, const void *b) {
+ const ClientContext *x = a, *y = b;
+ int r;
+
+ r = CMP(x->timestamp, y->timestamp);
+ if (r != 0)
+ return r;
+
+ return CMP(x->pid, y->pid);
+}
+
+static int client_context_new(Server *s, pid_t pid, ClientContext **ret) {
+ ClientContext *c;
+ int r;
+
+ assert(s);
+ assert(pid_is_valid(pid));
+ assert(ret);
+
+ r = hashmap_ensure_allocated(&s->client_contexts, NULL);
+ if (r < 0)
+ return r;
+
+ r = prioq_ensure_allocated(&s->client_contexts_lru, client_context_compare);
+ if (r < 0)
+ return r;
+
+ c = new(ClientContext, 1);
+ if (!c)
+ return -ENOMEM;
+
+ *c = (ClientContext) {
+ .pid = pid,
+ .uid = UID_INVALID,
+ .gid = GID_INVALID,
+ .auditid = AUDIT_SESSION_INVALID,
+ .loginuid = UID_INVALID,
+ .owner_uid = UID_INVALID,
+ .lru_index = PRIOQ_IDX_NULL,
+ .timestamp = USEC_INFINITY,
+ .extra_fields_mtime = NSEC_INFINITY,
+ .log_level_max = -1,
+ .log_ratelimit_interval = s->ratelimit_interval,
+ .log_ratelimit_burst = s->ratelimit_burst,
+ };
+
+ r = hashmap_put(s->client_contexts, PID_TO_PTR(pid), c);
+ if (r < 0) {
+ free(c);
+ return r;
+ }
+
+ *ret = c;
+ return 0;
+}
+
+static void client_context_reset(Server *s, ClientContext *c) {
+ assert(s);
+ assert(c);
+
+ c->timestamp = USEC_INFINITY;
+
+ c->uid = UID_INVALID;
+ c->gid = GID_INVALID;
+
+ c->comm = mfree(c->comm);
+ c->exe = mfree(c->exe);
+ c->cmdline = mfree(c->cmdline);
+ c->capeff = mfree(c->capeff);
+
+ c->auditid = AUDIT_SESSION_INVALID;
+ c->loginuid = UID_INVALID;
+
+ c->cgroup = mfree(c->cgroup);
+ c->session = mfree(c->session);
+ c->owner_uid = UID_INVALID;
+ c->unit = mfree(c->unit);
+ c->user_unit = mfree(c->user_unit);
+ c->slice = mfree(c->slice);
+ c->user_slice = mfree(c->user_slice);
+
+ c->invocation_id = SD_ID128_NULL;
+
+ c->label = mfree(c->label);
+ c->label_size = 0;
+
+ c->extra_fields_iovec = mfree(c->extra_fields_iovec);
+ c->extra_fields_n_iovec = 0;
+ c->extra_fields_data = mfree(c->extra_fields_data);
+ c->extra_fields_mtime = NSEC_INFINITY;
+
+ c->log_level_max = -1;
+
+ c->log_ratelimit_interval = s->ratelimit_interval;
+ c->log_ratelimit_burst = s->ratelimit_burst;
+}
+
+static ClientContext* client_context_free(Server *s, ClientContext *c) {
+ assert(s);
+
+ if (!c)
+ return NULL;
+
+ assert_se(hashmap_remove(s->client_contexts, PID_TO_PTR(c->pid)) == c);
+
+ if (c->in_lru)
+ assert_se(prioq_remove(s->client_contexts_lru, c, &c->lru_index) >= 0);
+
+ client_context_reset(s, c);
+
+ return mfree(c);
+}
+
+static void client_context_read_uid_gid(ClientContext *c, const struct ucred *ucred) {
+ assert(c);
+ assert(pid_is_valid(c->pid));
+
+ /* The ucred data passed in is always the most current and accurate, if we have any. Use it. */
+ if (ucred && uid_is_valid(ucred->uid))
+ c->uid = ucred->uid;
+ else
+ (void) get_process_uid(c->pid, &c->uid);
+
+ if (ucred && gid_is_valid(ucred->gid))
+ c->gid = ucred->gid;
+ else
+ (void) get_process_gid(c->pid, &c->gid);
+}
+
+static void client_context_read_basic(ClientContext *c) {
+ char *t;
+
+ assert(c);
+ assert(pid_is_valid(c->pid));
+
+ if (get_process_comm(c->pid, &t) >= 0)
+ free_and_replace(c->comm, t);
+
+ if (get_process_exe(c->pid, &t) >= 0)
+ free_and_replace(c->exe, t);
+
+ if (get_process_cmdline(c->pid, SIZE_MAX, 0, &t) >= 0)
+ free_and_replace(c->cmdline, t);
+
+ if (get_process_capeff(c->pid, &t) >= 0)
+ free_and_replace(c->capeff, t);
+}
+
+static int client_context_read_label(
+ ClientContext *c,
+ const char *label, size_t label_size) {
+
+ assert(c);
+ assert(pid_is_valid(c->pid));
+ assert(label_size == 0 || label);
+
+ if (label_size > 0) {
+ char *l;
+
+ /* If we got an SELinux label passed in it counts. */
+
+ l = newdup_suffix0(char, label, label_size);
+ if (!l)
+ return -ENOMEM;
+
+ free_and_replace(c->label, l);
+ c->label_size = label_size;
+ }
+#if HAVE_SELINUX
+ else {
+ char *con;
+
+ /* If we got no SELinux label passed in, let's try to acquire one */
+
+ if (getpidcon(c->pid, &con) >= 0) {
+ free_and_replace(c->label, con);
+ c->label_size = strlen(c->label);
+ }
+ }
+#endif
+
+ return 0;
+}
+
+static int client_context_read_cgroup(Server *s, ClientContext *c, const char *unit_id) {
+ _cleanup_free_ char *t = NULL;
+ int r;
+
+ assert(c);
+
+ /* Try to acquire the current cgroup path */
+ r = cg_pid_get_path_shifted(c->pid, s->cgroup_root, &t);
+ if (r < 0 || empty_or_root(t)) {
+ /* We use the unit ID passed in as fallback if we have nothing cached yet and cg_pid_get_path_shifted()
+ * failed or process is running in a root cgroup. Zombie processes are automatically migrated to root cgroup
+ * on cgroup v1 and we want to be able to map log messages from them too. */
+ if (unit_id && !c->unit) {
+ c->unit = strdup(unit_id);
+ if (c->unit)
+ return 0;
+ }
+
+ return r;
+ }
+
+ /* Let's shortcut this if the cgroup path didn't change */
+ if (streq_ptr(c->cgroup, t))
+ return 0;
+
+ free_and_replace(c->cgroup, t);
+
+ (void) cg_path_get_session(c->cgroup, &t);
+ free_and_replace(c->session, t);
+
+ if (cg_path_get_owner_uid(c->cgroup, &c->owner_uid) < 0)
+ c->owner_uid = UID_INVALID;
+
+ (void) cg_path_get_unit(c->cgroup, &t);
+ free_and_replace(c->unit, t);
+
+ (void) cg_path_get_user_unit(c->cgroup, &t);
+ free_and_replace(c->user_unit, t);
+
+ (void) cg_path_get_slice(c->cgroup, &t);
+ free_and_replace(c->slice, t);
+
+ (void) cg_path_get_user_slice(c->cgroup, &t);
+ free_and_replace(c->user_slice, t);
+
+ return 0;
+}
+
+static int client_context_read_invocation_id(
+ Server *s,
+ ClientContext *c) {
+
+ _cleanup_free_ char *p = NULL, *value = NULL;
+ int r;
+
+ assert(s);
+ assert(c);
+
+ /* Read the invocation ID of a unit off a unit.
+ * PID 1 stores it in a per-unit symlink in /run/systemd/units/
+ * User managers store it in a per-unit symlink under /run/user/<uid>/systemd/units/ */
+
+ if (!c->unit)
+ return 0;
+
+ if (c->user_unit) {
+ r = asprintf(&p, "/run/user/" UID_FMT "/systemd/units/invocation:%s", c->owner_uid, c->user_unit);
+ if (r < 0)
+ return r;
+ } else {
+ p = strjoin("/run/systemd/units/invocation:", c->unit);
+ if (!p)
+ return -ENOMEM;
+ }
+
+ r = readlink_malloc(p, &value);
+ if (r < 0)
+ return r;
+
+ return sd_id128_from_string(value, &c->invocation_id);
+}
+
+static int client_context_read_log_level_max(
+ Server *s,
+ ClientContext *c) {
+
+ _cleanup_free_ char *value = NULL;
+ const char *p;
+ int r, ll;
+
+ if (!c->unit)
+ return 0;
+
+ p = strjoina("/run/systemd/units/log-level-max:", c->unit);
+ r = readlink_malloc(p, &value);
+ if (r < 0)
+ return r;
+
+ ll = log_level_from_string(value);
+ if (ll < 0)
+ return -EINVAL;
+
+ c->log_level_max = ll;
+ return 0;
+}
+
+static int client_context_read_extra_fields(
+ Server *s,
+ ClientContext *c) {
+
+ size_t size = 0, n_iovec = 0, n_allocated = 0, left;
+ _cleanup_free_ struct iovec *iovec = NULL;
+ _cleanup_free_ void *data = NULL;
+ _cleanup_fclose_ FILE *f = NULL;
+ struct stat st;
+ const char *p;
+ uint8_t *q;
+ int r;
+
+ if (!c->unit)
+ return 0;
+
+ p = strjoina("/run/systemd/units/log-extra-fields:", c->unit);
+
+ if (c->extra_fields_mtime != NSEC_INFINITY) {
+ if (stat(p, &st) < 0) {
+ if (errno == ENOENT)
+ return 0;
+
+ return -errno;
+ }
+
+ if (timespec_load_nsec(&st.st_mtim) == c->extra_fields_mtime)
+ return 0;
+ }
+
+ f = fopen(p, "re");
+ if (!f) {
+ if (errno == ENOENT)
+ return 0;
+
+ return -errno;
+ }
+
+ if (fstat(fileno(f), &st) < 0) /* The file might have been replaced since the stat() above, let's get a new
+ * one, that matches the stuff we are reading */
+ return -errno;
+
+ r = read_full_stream(f, (char**) &data, &size);
+ if (r < 0)
+ return r;
+
+ q = data, left = size;
+ while (left > 0) {
+ uint8_t *field, *eq;
+ uint64_t v, n;
+
+ if (left < sizeof(uint64_t))
+ return -EBADMSG;
+
+ v = unaligned_read_le64(q);
+ if (v < 2)
+ return -EBADMSG;
+
+ n = sizeof(uint64_t) + v;
+ if (left < n)
+ return -EBADMSG;
+
+ field = q + sizeof(uint64_t);
+
+ eq = memchr(field, '=', v);
+ if (!eq)
+ return -EBADMSG;
+
+ if (!journal_field_valid((const char *) field, eq - field, false))
+ return -EBADMSG;
+
+ if (!GREEDY_REALLOC(iovec, n_allocated, n_iovec+1))
+ return -ENOMEM;
+
+ iovec[n_iovec++] = IOVEC_MAKE(field, v);
+
+ left -= n, q += n;
+ }
+
+ free(c->extra_fields_iovec);
+ free(c->extra_fields_data);
+
+ c->extra_fields_iovec = TAKE_PTR(iovec);
+ c->extra_fields_n_iovec = n_iovec;
+ c->extra_fields_data = TAKE_PTR(data);
+ c->extra_fields_mtime = timespec_load_nsec(&st.st_mtim);
+
+ return 0;
+}
+
+static int client_context_read_log_ratelimit_interval(ClientContext *c) {
+ _cleanup_free_ char *value = NULL;
+ const char *p;
+ int r;
+
+ assert(c);
+
+ if (!c->unit)
+ return 0;
+
+ p = strjoina("/run/systemd/units/log-rate-limit-interval:", c->unit);
+ r = readlink_malloc(p, &value);
+ if (r < 0)
+ return r;
+
+ return safe_atou64(value, &c->log_ratelimit_interval);
+}
+
+static int client_context_read_log_ratelimit_burst(ClientContext *c) {
+ _cleanup_free_ char *value = NULL;
+ const char *p;
+ int r;
+
+ assert(c);
+
+ if (!c->unit)
+ return 0;
+
+ p = strjoina("/run/systemd/units/log-rate-limit-burst:", c->unit);
+ r = readlink_malloc(p, &value);
+ if (r < 0)
+ return r;
+
+ return safe_atou(value, &c->log_ratelimit_burst);
+}
+
+static void client_context_really_refresh(
+ Server *s,
+ ClientContext *c,
+ const struct ucred *ucred,
+ const char *label, size_t label_size,
+ const char *unit_id,
+ usec_t timestamp) {
+
+ assert(s);
+ assert(c);
+ assert(pid_is_valid(c->pid));
+
+ if (timestamp == USEC_INFINITY)
+ timestamp = now(CLOCK_MONOTONIC);
+
+ client_context_read_uid_gid(c, ucred);
+ client_context_read_basic(c);
+ (void) client_context_read_label(c, label, label_size);
+
+ (void) audit_session_from_pid(c->pid, &c->auditid);
+ (void) audit_loginuid_from_pid(c->pid, &c->loginuid);
+
+ (void) client_context_read_cgroup(s, c, unit_id);
+ (void) client_context_read_invocation_id(s, c);
+ (void) client_context_read_log_level_max(s, c);
+ (void) client_context_read_extra_fields(s, c);
+ (void) client_context_read_log_ratelimit_interval(c);
+ (void) client_context_read_log_ratelimit_burst(c);
+
+ c->timestamp = timestamp;
+
+ if (c->in_lru) {
+ assert(c->n_ref == 0);
+ assert_se(prioq_reshuffle(s->client_contexts_lru, c, &c->lru_index) >= 0);
+ }
+}
+
+void client_context_maybe_refresh(
+ Server *s,
+ ClientContext *c,
+ const struct ucred *ucred,
+ const char *label, size_t label_size,
+ const char *unit_id,
+ usec_t timestamp) {
+
+ assert(s);
+ assert(c);
+
+ if (timestamp == USEC_INFINITY)
+ timestamp = now(CLOCK_MONOTONIC);
+
+ /* No cached data so far? Let's fill it up */
+ if (c->timestamp == USEC_INFINITY)
+ goto refresh;
+
+ /* If the data isn't pinned and if the cashed data is older than the upper limit, we flush it out
+ * entirely. This follows the logic that as long as an entry is pinned the PID reuse is unlikely. */
+ if (c->n_ref == 0 && c->timestamp + MAX_USEC < timestamp) {
+ client_context_reset(s, c);
+ goto refresh;
+ }
+
+ /* If the data is older than the lower limit, we refresh, but keep the old data for all we can't update */
+ if (c->timestamp + REFRESH_USEC < timestamp)
+ goto refresh;
+
+ /* If the data passed along doesn't match the cached data we also do a refresh */
+ if (ucred && uid_is_valid(ucred->uid) && c->uid != ucred->uid)
+ goto refresh;
+
+ if (ucred && gid_is_valid(ucred->gid) && c->gid != ucred->gid)
+ goto refresh;
+
+ if (label_size > 0 && (label_size != c->label_size || memcmp(label, c->label, label_size) != 0))
+ goto refresh;
+
+ return;
+
+refresh:
+ client_context_really_refresh(s, c, ucred, label, label_size, unit_id, timestamp);
+}
+
+static void client_context_try_shrink_to(Server *s, size_t limit) {
+ ClientContext *c;
+ usec_t t;
+
+ assert(s);
+
+ /* Flush any cache entries for PIDs that have already moved on. Don't do this
+ * too often, since it's a slow process. */
+ t = now(CLOCK_MONOTONIC);
+ if (s->last_cache_pid_flush + MAX_USEC < t) {
+ unsigned n = prioq_size(s->client_contexts_lru), idx = 0;
+
+ /* We do a number of iterations based on the initial size of the prioq. When we remove an
+ * item, a new item is moved into its places, and items to the right might be reshuffled.
+ */
+ for (unsigned i = 0; i < n; i++) {
+ c = prioq_peek_by_index(s->client_contexts_lru, idx);
+
+ assert(c->n_ref == 0);
+
+ if (!pid_is_unwaited(c->pid))
+ client_context_free(s, c);
+ else
+ idx ++;
+ }
+
+ s->last_cache_pid_flush = t;
+ }
+
+ /* Bring the number of cache entries below the indicated limit, so that we can create a new entry without
+ * breaching the limit. Note that we only flush out entries that aren't pinned here. This means the number of
+ * cache entries may very well grow beyond the limit, if all entries stored remain pinned. */
+
+ while (hashmap_size(s->client_contexts) > limit) {
+ c = prioq_pop(s->client_contexts_lru);
+ if (!c)
+ break; /* All remaining entries are pinned, give up */
+
+ assert(c->in_lru);
+ assert(c->n_ref == 0);
+
+ c->in_lru = false;
+
+ client_context_free(s, c);
+ }
+}
+
+void client_context_flush_all(Server *s) {
+ assert(s);
+
+ /* Flush out all remaining entries. This assumes all references are already dropped. */
+
+ s->my_context = client_context_release(s, s->my_context);
+ s->pid1_context = client_context_release(s, s->pid1_context);
+
+ client_context_try_shrink_to(s, 0);
+
+ assert(prioq_size(s->client_contexts_lru) == 0);
+ assert(hashmap_size(s->client_contexts) == 0);
+
+ s->client_contexts_lru = prioq_free(s->client_contexts_lru);
+ s->client_contexts = hashmap_free(s->client_contexts);
+}
+
+static int client_context_get_internal(
+ Server *s,
+ pid_t pid,
+ const struct ucred *ucred,
+ const char *label, size_t label_len,
+ const char *unit_id,
+ bool add_ref,
+ ClientContext **ret) {
+
+ ClientContext *c;
+ int r;
+
+ assert(s);
+ assert(ret);
+
+ if (!pid_is_valid(pid))
+ return -EINVAL;
+
+ c = hashmap_get(s->client_contexts, PID_TO_PTR(pid));
+ if (c) {
+
+ if (add_ref) {
+ if (c->in_lru) {
+ /* The entry wasn't pinned so far, let's remove it from the LRU list then */
+ assert(c->n_ref == 0);
+ assert_se(prioq_remove(s->client_contexts_lru, c, &c->lru_index) >= 0);
+ c->in_lru = false;
+ }
+
+ c->n_ref++;
+ }
+
+ client_context_maybe_refresh(s, c, ucred, label, label_len, unit_id, USEC_INFINITY);
+
+ *ret = c;
+ return 0;
+ }
+
+ client_context_try_shrink_to(s, cache_max()-1);
+
+ r = client_context_new(s, pid, &c);
+ if (r < 0)
+ return r;
+
+ if (add_ref)
+ c->n_ref++;
+ else {
+ r = prioq_put(s->client_contexts_lru, c, &c->lru_index);
+ if (r < 0) {
+ client_context_free(s, c);
+ return r;
+ }
+
+ c->in_lru = true;
+ }
+
+ client_context_really_refresh(s, c, ucred, label, label_len, unit_id, USEC_INFINITY);
+
+ *ret = c;
+ return 0;
+}
+
+int client_context_get(
+ Server *s,
+ pid_t pid,
+ const struct ucred *ucred,
+ const char *label, size_t label_len,
+ const char *unit_id,
+ ClientContext **ret) {
+
+ return client_context_get_internal(s, pid, ucred, label, label_len, unit_id, false, ret);
+}
+
+int client_context_acquire(
+ Server *s,
+ pid_t pid,
+ const struct ucred *ucred,
+ const char *label, size_t label_len,
+ const char *unit_id,
+ ClientContext **ret) {
+
+ return client_context_get_internal(s, pid, ucred, label, label_len, unit_id, true, ret);
+};
+
+ClientContext *client_context_release(Server *s, ClientContext *c) {
+ assert(s);
+
+ if (!c)
+ return NULL;
+
+ assert(c->n_ref > 0);
+ assert(!c->in_lru);
+
+ c->n_ref--;
+ if (c->n_ref > 0)
+ return NULL;
+
+ /* The entry is not pinned anymore, let's add it to the LRU prioq if we can. If we can't we'll drop it
+ * right-away */
+
+ if (prioq_put(s->client_contexts_lru, c, &c->lru_index) < 0)
+ client_context_free(s, c);
+ else
+ c->in_lru = true;
+
+ return NULL;
+}
+
+void client_context_acquire_default(Server *s) {
+ int r;
+
+ assert(s);
+
+ /* Ensure that our own and PID1's contexts are always pinned. Our own context is particularly useful to
+ * generate driver messages. */
+
+ if (!s->my_context) {
+ struct ucred ucred = {
+ .pid = getpid_cached(),
+ .uid = getuid(),
+ .gid = getgid(),
+ };
+
+ r = client_context_acquire(s, ucred.pid, &ucred, NULL, 0, NULL, &s->my_context);
+ if (r < 0)
+ log_warning_errno(r, "Failed to acquire our own context, ignoring: %m");
+ }
+
+ if (!s->namespace && !s->pid1_context) {
+ /* Acquire PID1's context, but only if we are in non-namespaced mode, since PID 1 is only
+ * going to log to the non-namespaced journal instance. */
+
+ r = client_context_acquire(s, 1, NULL, NULL, 0, NULL, &s->pid1_context);
+ if (r < 0)
+ log_warning_errno(r, "Failed to acquire PID1's context, ignoring: %m");
+
+ }
+}