From 5659958529d16f082a24d0c5b68699570b3eace3 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Fri, 29 Apr 2016 19:14:52 +0200 Subject: 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. --- src/machine/image-dbus.c | 40 ++++++++++++++-- src/machine/machined.c | 8 ++++ src/machine/machined.h | 4 ++ src/machine/operation.c | 118 +++++++++++++++++++++++++++++++++++++++++++++++ src/machine/operation.h | 45 ++++++++++++++++++ 5 files changed, 210 insertions(+), 5 deletions(-) create mode 100644 src/machine/operation.c create mode 100644 src/machine/operation.h (limited to 'src/machine') diff --git a/src/machine/image-dbus.c b/src/machine/image-dbus.c index b764bc43a0..ca38f61dd3 100644 --- a/src/machine/image-dbus.c +++ b/src/machine/image-dbus.c @@ -20,9 +20,11 @@ #include "alloc-util.h" #include "bus-label.h" #include "bus-util.h" +#include "fd-util.h" #include "image-dbus.h" #include "io-util.h" #include "machine-image.h" +#include "process-util.h" #include "strv.h" #include "user-util.h" @@ -107,13 +109,19 @@ int bus_image_method_clone( void *userdata, sd_bus_error *error) { + _cleanup_close_pair_ int errno_pipe_fd[2] = { -1, -1 }; Image *image = userdata; Manager *m = image->userdata; const char *new_name; int r, read_only; + pid_t child; assert(message); assert(image); + assert(m); + + if (m->n_operations >= OPERATIONS_MAX) + return sd_bus_error_setf(error, SD_BUS_ERROR_LIMITS_EXCEEDED, "Too many ongoing operations."); r = sd_bus_message_read(message, "sb", &new_name, &read_only); if (r < 0) @@ -136,13 +144,35 @@ int bus_image_method_clone( if (r == 0) return 1; /* Will call us back */ - r = image_clone(image, new_name, read_only); - if (r == -EOPNOTSUPP) - return sd_bus_reply_method_errnof(message, r, "Image cloning is currently only supported on btrfs file systems."); - if (r < 0) + if (pipe2(errno_pipe_fd, O_CLOEXEC|O_NONBLOCK) < 0) + return sd_bus_error_set_errnof(error, errno, "Failed to create pipe: %m"); + + child = fork(); + if (child < 0) + return sd_bus_error_set_errnof(error, errno, "Failed to fork(): %m"); + if (child == 0) { + errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]); + + r = image_clone(image, new_name, read_only); + if (r < 0) { + (void) write(errno_pipe_fd[1], &r, sizeof(r)); + _exit(EXIT_FAILURE); + } + + _exit(EXIT_SUCCESS); + } + + errno_pipe_fd[1] = safe_close(errno_pipe_fd[1]); + + r = operation_new(m, child, message, errno_pipe_fd[0]); + if (r < 0) { + (void) sigkill_wait(&child); return r; + } - return sd_bus_reply_method_return(message, NULL); + errno_pipe_fd[0] = -1; + + return 1; } int bus_image_method_mark_read_only( diff --git a/src/machine/machined.c b/src/machine/machined.c index f2c1966a6b..f7ceb5e603 100644 --- a/src/machine/machined.c +++ b/src/machine/machined.c @@ -70,6 +70,11 @@ void manager_free(Manager *m) { assert(m); + while (m->operations) + operation_free(m->operations); + + assert(m->n_operations == 0); + while ((machine = hashmap_first(m->machines))) machine_free(machine); @@ -336,6 +341,9 @@ int manager_startup(Manager *m) { static bool check_idle(void *userdata) { Manager *m = userdata; + if (m->operations) + return false; + manager_gc(m, true); return hashmap_isempty(m->machines); diff --git a/src/machine/machined.h b/src/machine/machined.h index e7d7dfdceb..7b9b148044 100644 --- a/src/machine/machined.h +++ b/src/machine/machined.h @@ -32,6 +32,7 @@ typedef struct Manager Manager; #include "image-dbus.h" #include "machine-dbus.h" #include "machine.h" +#include "operation.h" struct Manager { sd_event *event; @@ -49,6 +50,9 @@ struct Manager { LIST_HEAD(Machine, machine_gc_queue); Machine *host_machine; + + LIST_HEAD(Operation, operations); + unsigned n_operations; }; Manager *manager_new(void); 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 . +***/ + +#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; +} diff --git a/src/machine/operation.h b/src/machine/operation.h new file mode 100644 index 0000000000..9d4c3afe45 --- /dev/null +++ b/src/machine/operation.h @@ -0,0 +1,45 @@ +#pragma once + +/*** + 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 . +***/ + +#include + +#include "sd-bus.h" +#include "sd-event.h" + +#include "list.h" + +typedef struct Operation Operation; + +#include "machined.h" + +#define OPERATIONS_MAX 64 + +struct Operation { + Manager *manager; + pid_t pid; + sd_bus_message *message; + int errno_fd; + sd_event_source *event_source; + LIST_FIELDS(Operation, operations); +}; + +int operation_new(Manager *m, pid_t child, sd_bus_message *message, int errno_fd); +Operation *operation_free(Operation *o); -- cgit v1.2.3-54-g00ecf