From 6772555b226a116bff07b7d8af28b16032273866 Mon Sep 17 00:00:00 2001
From: David Tardon <dtardon@redhat.com>
Date: Wed, 9 May 2018 09:35:52 +0200
Subject: [PATCH] systemd-analyze: make dump work for large # of units
If there is a large number of units, the size of the generated dump
string can overstep DBus message size limit. So let's pass that string
via a fd.
(cherry picked from commit c0a1bfacfea9c65ea79fd07682a5b60b5d711a33)
Resolves: #1446095
---
src/analyze/analyze.c | 57 ++++++++++++++++++++++----
src/core/dbus-manager.c | 26 +++++++++++-
src/core/org.freedesktop.systemd1.conf | 4 ++
3 files changed, 76 insertions(+), 11 deletions(-)
diff --git a/src/analyze/analyze.c b/src/analyze/analyze.c
index ff84f6894f..7116aaa88d 100644
--- a/src/analyze/analyze.c
+++ b/src/analyze/analyze.c
@@ -29,6 +29,7 @@
#include "sd-bus.h"
#include "bus-util.h"
#include "bus-error.h"
+#include "copy.h"
#include "install.h"
#include "log.h"
#include "build.h"
@@ -1096,12 +1097,42 @@ static int dot(sd_bus *bus, char* patterns[]) {
return 0;
}
-static int dump(sd_bus *bus, char **args) {
- _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
- _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+static int dump_fallback(sd_bus *bus) {
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
const char *text = NULL;
int r;
+ assert(bus);
+
+ r = sd_bus_call_method(
+ bus,
+ "org.freedesktop.systemd1",
+ "/org/freedesktop/systemd1",
+ "org.freedesktop.systemd1.Manager",
+ "Dump",
+ &error,
+ &reply,
+ "");
+ if (r < 0) {
+ log_error("Failed to issue method call Dump: %s", bus_error_message(&error, -r));
+ return r;
+ }
+
+ r = sd_bus_message_read(reply, "s", &text);
+ if (r < 0)
+ return bus_log_parse_error(r);
+
+ fputs(text, stdout);
+ return 0;
+}
+
+static int dump(sd_bus *bus, char **args) {
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+ int fd = -1;
+ int r;
+
if (!strv_isempty(args)) {
log_error("Too many arguments.");
return -E2BIG;
@@ -1109,26 +1140,34 @@ static int dump(sd_bus *bus, char **args) {
pager_open_if_enabled();
+ if (!sd_bus_can_send(bus, SD_BUS_TYPE_UNIX_FD))
+ return dump_fallback(bus);
+
r = sd_bus_call_method(
bus,
"org.freedesktop.systemd1",
"/org/freedesktop/systemd1",
"org.freedesktop.systemd1.Manager",
- "Dump",
+ "DumpByFileDescriptor",
&error,
&reply,
"");
if (r < 0) {
- log_error("Failed issue method call: %s", bus_error_message(&error, -r));
- return r;
+ /* fall back to Dump if DumpByFileDescriptor is not supported */
+ if (!IN_SET(r, -EACCES, -EBADR)) {
+ log_error("Failed to issue method call DumpByFileDescriptor: %s", bus_error_message(&error, -r));
+ return r;
+ }
+
+ return dump_fallback(bus);
}
- r = sd_bus_message_read(reply, "s", &text);
+ r = sd_bus_message_read(reply, "h", &fd);
if (r < 0)
return bus_log_parse_error(r);
- fputs(text, stdout);
- return 0;
+ fflush(stdout);
+ return copy_bytes(fd, STDOUT_FILENO, (uint64_t) -1, 0);
}
static int set_log_level(sd_bus *bus, char **args) {
diff --git a/src/core/dbus-manager.c b/src/core/dbus-manager.c
index d34ed042f6..1766163b33 100644
--- a/src/core/dbus-manager.c
+++ b/src/core/dbus-manager.c
@@ -1064,7 +1064,7 @@ static int method_unsubscribe(sd_bus *bus, sd_bus_message *message, void *userda
return sd_bus_reply_method_return(message, NULL);
}
-static int method_dump(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
+static int dump_impl(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error, int (*reply)(sd_bus_message *, char *)) {
_cleanup_free_ char *dump = NULL;
_cleanup_fclose_ FILE *f = NULL;
Manager *m = userdata;
@@ -1089,13 +1089,34 @@ static int method_dump(sd_bus *bus, sd_bus_message *message, void *userdata, sd_
manager_dump_jobs(m, f, NULL);
fflush(f);
-
if (ferror(f))
return -ENOMEM;
+ return reply(message, dump);
+}
+
+static int reply_dump(sd_bus_message *message, char *dump) {
return sd_bus_reply_method_return(message, "s", dump);
}
+static int method_dump(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
+ return dump_impl(bus, message, userdata, error, reply_dump);
+}
+
+static int reply_dump_by_fd(sd_bus_message *message, char *dump) {
+ _cleanup_close_ int fd = -1;
+
+ fd = acquire_data_fd(dump, strlen(dump), 0);
+ if (fd < 0)
+ return fd;
+
+ return sd_bus_reply_method_return(message, "h", fd);
+}
+
+static int method_dump_by_fd(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
+ return dump_impl(bus, message, userdata, error, reply_dump_by_fd);
+}
+
static int method_create_snapshot(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
_cleanup_free_ char *path = NULL;
Manager *m = userdata;
@@ -2092,6 +2113,7 @@ const sd_bus_vtable bus_manager_vtable[] = {
SD_BUS_METHOD("Subscribe", NULL, NULL, method_subscribe, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("Unsubscribe", NULL, NULL, method_unsubscribe, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("Dump", NULL, "s", method_dump, SD_BUS_VTABLE_UNPRIVILEGED),
+ SD_BUS_METHOD("DumpByFileDescriptor", NULL, "h", method_dump_by_fd, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("CreateSnapshot", "sb", "o", method_create_snapshot, 0),
SD_BUS_METHOD("RemoveSnapshot", "s", NULL, method_remove_snapshot, 0),
SD_BUS_METHOD("Reload", NULL, NULL, method_reload, SD_BUS_VTABLE_UNPRIVILEGED),
diff --git a/src/core/org.freedesktop.systemd1.conf b/src/core/org.freedesktop.systemd1.conf
index 3997dd0b4e..8187cf1731 100644
--- a/src/core/org.freedesktop.systemd1.conf
+++ b/src/core/org.freedesktop.systemd1.conf
@@ -96,6 +96,10 @@
send_interface="org.freedesktop.systemd1.Manager"
send_member="Dump"/>
+ <allow send_destination="org.freedesktop.systemd1"
+ send_interface="org.freedesktop.systemd1.Manager"
+ send_member="DumpByFileDescriptor"/>
+
<allow send_destination="org.freedesktop.systemd1"
send_interface="org.freedesktop.systemd1.Manager"
send_member="GetDefaultTarget"/>