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authorLennart Poettering <lennart@poettering.net>2016-04-29 19:14:52 +0200
committerLennart Poettering <lennart@poettering.net>2016-05-02 11:15:30 +0200
commit5659958529d16f082a24d0c5b68699570b3eace3 (patch)
tree087d89d87288487942caf8e4d29c9aedc1f1e8e3 /src/machine/operation.c
parent26ccc1d0875b0e0c4306b03a52aff712c23d46c7 (diff)
machined: run clone operation asynchronously in the background
Cloning an image can be slow, if the image is not on a btrfs subvolume, hence let's make sure we do this asynchronously in a child process, so that machined isn't blocked as long as we process the client request. This adds a new, generic "Operation" object to machined, that is used to track these kind of background processes. This is inspired by the MachineOperation object that already exists to make copy operations asynchronous. A later patch will rework the MachineOperation logic to use the generic Operation instead.
Diffstat (limited to 'src/machine/operation.c')
-rw-r--r--src/machine/operation.c118
1 files changed, 118 insertions, 0 deletions
diff --git a/src/machine/operation.c b/src/machine/operation.c
new file mode 100644
index 0000000000..53e996b48f
--- /dev/null
+++ b/src/machine/operation.c
@@ -0,0 +1,118 @@
+/***
+ This file is part of systemd.
+
+ Copyright 2016 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "operation.h"
+#include "process-util.h"
+
+static int operation_done(sd_event_source *s, const siginfo_t *si, void *userdata) {
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ Operation *o = userdata;
+ int r;
+
+ assert(o);
+ assert(si);
+
+ log_debug("Operating " PID_FMT " is now complete with with code=%s status=%i",
+ o->pid,
+ sigchld_code_to_string(si->si_code), si->si_status);
+
+ o->pid = 0;
+
+ if (si->si_code != CLD_EXITED) {
+ r = sd_bus_error_setf(&error, SD_BUS_ERROR_FAILED, "Child died abnormally.");
+ goto fail;
+ }
+
+ if (si->si_status != EXIT_SUCCESS) {
+ if (read(o->errno_fd, &r, sizeof(r)) == sizeof(r))
+ r = sd_bus_error_set_errnof(&error, r, "%m");
+ else
+ r = sd_bus_error_setf(&error, SD_BUS_ERROR_FAILED, "Child failed.");
+
+ goto fail;
+ }
+
+ r = sd_bus_reply_method_return(o->message, NULL);
+ if (r < 0)
+ log_error_errno(r, "Failed to reply to message: %m");
+
+ operation_free(o);
+ return 0;
+
+fail:
+ r = sd_bus_reply_method_error(o->message, &error);
+ if (r < 0)
+ log_error_errno(r, "Failed to reply to message: %m");
+
+ operation_free(o);
+ return 0;
+}
+
+int operation_new(Manager *m, pid_t child, sd_bus_message *message, int errno_fd) {
+ Operation *o;
+ int r;
+
+ o = new0(Operation, 1);
+ if (!o)
+ return -ENOMEM;
+
+ r = sd_event_add_child(m->event, &o->event_source, child, WEXITED, operation_done, o);
+ if (r < 0) {
+ free(o);
+ return r;
+ }
+
+ o->pid = child;
+ o->message = sd_bus_message_ref(message);
+ o->errno_fd = errno_fd;
+
+ LIST_PREPEND(operations, m->operations, o);
+ m->n_operations++;
+ o->manager = m;
+
+ log_debug("Started new operation " PID_FMT ".", child);
+
+ /* At this point we took ownership of both the child and the errno file descriptor! */
+
+ return 0;
+}
+
+Operation *operation_free(Operation *o) {
+ if (!o)
+ return NULL;
+
+ sd_event_source_unref(o->event_source);
+
+ safe_close(o->errno_fd);
+
+ if (o->pid > 1)
+ (void) sigkill_wait(&o->pid);
+
+ sd_bus_message_unref(o->message);
+
+ if (o->manager) {
+ LIST_REMOVE(operations, o->manager->operations, o);
+ o->manager->n_operations--;
+ }
+
+ free(o);
+ return NULL;
+}