swap: add .swap unit type

11 files changed, 659 insertions, 43 deletions

diff --git a/Makefile.am b/Makefile.am
index c38c7d575c..115cd0530f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -112,6 +112,8 @@ COMMON_SOURCES = \
         automount.h \
         mount.c \
         mount.h \
+        swap.c \
+        swap.h \
         device.c \
         device.h \
         target.c \
@@ -144,6 +146,8 @@ COMMON_SOURCES = \
 	dbus-mount.h \
 	dbus-automount.c \
 	dbus-autpmount.h \
+	dbus-swap.c \
+	dbus-swap.h \
 	dbus-snapshot.c \
 	dbus-snapshot.h \
 	dbus-device.c \
diff --git a/dbus-swap.c b/dbus-swap.c
new file mode 100644
index 0000000000..6939ae29c7
--- /dev/null
+++ b/dbus-swap.c
@@ -0,0 +1,47 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+  Copyright 2010 Maarten Lankhorst
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "dbus-unit.h"
+#include "dbus-swap.h"
+
+static const char introspection[] =
+        DBUS_INTROSPECT_1_0_XML_DOCTYPE_DECL_NODE
+        "<node>"
+        BUS_UNIT_INTERFACE
+        BUS_PROPERTIES_INTERFACE
+        " <interface name=\"org.freedesktop.systemd1.Swap\">"
+        "  <property name=\"What\" type=\"s\" access=\"read\"/>"
+        "  <property name=\"Priority\" type=\"i\" access=\"read\"/>"
+        " </interface>"
+        BUS_INTROSPECTABLE_INTERFACE
+        "</node>";
+
+DBusHandlerResult bus_swap_message_handler(Unit *u, DBusMessage *message) {
+        const BusProperty properties[] = {
+                BUS_UNIT_PROPERTIES,
+                { "org.freedesktop.systemd1.Swap", "What", bus_property_append_string, "s", u->swap.what },
+                { "org.freedesktop.systemd1.Swap", "Priority", bus_property_append_int32, "i", &u->swap.priority },
+                { NULL, NULL, NULL, NULL, NULL }
+        };
+
+        return bus_default_message_handler(u->meta.manager, message, introspection, properties);
+}
diff --git a/dbus-swap.h b/dbus-swap.h
new file mode 100644
index 0000000000..3bef6ad621
--- /dev/null
+++ b/dbus-swap.h
@@ -0,0 +1,32 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+#ifndef foodbusswaphfoo
+#define foodbusswaphfoo
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+  Copyright 2010 Maarten Lankhorst
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <dbus/dbus.h>
+
+#include "unit.h"
+
+DBusHandlerResult bus_swap_message_handler(Unit *u, DBusMessage *message);
+
+#endif
diff --git a/load-fragment.c b/load-fragment.c
index 0dfb49f113..b4e0c76009 100644
--- a/load-fragment.c
+++ b/load-fragment.c
@@ -1171,7 +1171,8 @@ static int load_from_path(Unit *u, const char *path) {
                 [UNIT_DEVICE]    = "Device",
                 [UNIT_MOUNT]     = "Mount",
                 [UNIT_AUTOMOUNT] = "Automount",
-                [UNIT_SNAPSHOT]  = "Snapshot"
+                [UNIT_SNAPSHOT]  = "Snapshot",
+                [UNIT_SWAP]      = "Swap"
         };
 
 #define EXEC_CONTEXT_CONFIG_ITEMS(context, section) \
@@ -1286,6 +1287,10 @@ static int load_from_path(Unit *u, const char *path) {
 
                 { "Where",                  config_parse_path,            &u->automount.where,                             "Automount" },
 
+                { "What",                   config_parse_path,            &u->swap.what,                                   "Swap" },
+                { "Priority",               config_parse_unsigned,        &u->swap.priority,                               "Swap" },
+                { "NoAuto",                 config_parse_bool,            &u->swap.no_auto,                                "Swap" },
+
                 { NULL, NULL, NULL, NULL }
         };
 
diff --git a/manager.h b/manager.h
index 0a09430f56..b6b6926bd8 100644
--- a/manager.h
+++ b/manager.h
@@ -99,6 +99,7 @@ struct Watch {
 
 #define SPECIAL_LOCAL_FS_TARGET "local-fs.target"
 #define SPECIAL_REMOTE_FS_TARGET "remote-fs.target"
+#define SPECIAL_SWAP_TARGET "swap.target"
 #define SPECIAL_NETWORK_TARGET "network.target"
 #define SPECIAL_NSS_LOOKUP_TARGET "nss-lookup.target"     /* LSB's $named */
 #define SPECIAL_RPCBIND_TARGET "rpcbind.target"           /* LSB's $portmap */
@@ -187,6 +188,9 @@ struct Manager {
         FILE *proc_self_mountinfo;
         Watch mount_watch;
 
+        /* Data specific to the swap filesystem */
+        FILE *proc_swaps;
+
         /* Data specific to the D-Bus subsystem */
         DBusConnection *api_bus, *system_bus;
         Set *subscribed;
diff --git a/mount.c b/mount.c
index 55f11341a6..c989cddabf 100644
--- a/mount.c
+++ b/mount.c
@@ -113,87 +113,82 @@ static void mount_done(Unit *u) {
         unit_unwatch_timer(u, &m->timer_watch);
 }
 
-static int mount_add_node_links(Mount *m) {
+int mount_add_node_links(Unit *u, const char *what) {
         Unit *device;
         char *e;
         int r;
-        const char *what;
 
-        assert(m);
-
-        /* Adds in links to the device that this node is based on */
+        assert(u);
 
-        if (m->parameters_fragment.what)
-                what = m->parameters_fragment.what;
-        else if (m->parameters_etc_fstab.what)
-                what = m->parameters_etc_fstab.what;
-        else
+        if (!what)
                 /* We observe kernel mounts only while they are live,
                  * hence don't create any links for them */
                 return 0;
 
+        /* Adds in links to the device that this node is based on */
+
         if (!path_startswith(what, "/dev/"))
                 return 0;
 
         if (!(e = unit_name_build_escape(what+1, NULL, ".device")))
                 return -ENOMEM;
 
-        r = manager_load_unit(UNIT(m)->meta.manager, e, NULL, &device);
+        r = manager_load_unit(u->meta.manager, e, NULL, &device);
         free(e);
 
         if (r < 0)
                 return r;
 
-        if ((r = unit_add_dependency(UNIT(m), UNIT_AFTER, device, true)) < 0)
+        if ((r = unit_add_dependency(u, UNIT_AFTER, device, true)) < 0)
                 return r;
 
-        if ((r = unit_add_dependency(UNIT(m), UNIT_REQUIRES, device, true)) < 0)
+        if ((r = unit_add_dependency(u, UNIT_REQUIRES, device, true)) < 0)
                 return r;
 
-        if (UNIT(m)->meta.manager->running_as == MANAGER_INIT ||
-            UNIT(m)->meta.manager->running_as == MANAGER_SYSTEM)
-                if ((r = unit_add_dependency(device, UNIT_WANTS, UNIT(m), false)) < 0)
+        if (u->meta.manager->running_as == MANAGER_INIT ||
+            u->meta.manager->running_as == MANAGER_SYSTEM)
+                if ((r = unit_add_dependency(device, UNIT_WANTS, u, false)) < 0)
                         return r;
 
         return 0;
 }
 
-static int mount_add_path_links(Mount *m) {
+int mount_add_path_links(Unit *u, const char *where, bool requires) {
         Meta *other;
         int r;
 
-        assert(m);
+        assert(u);
 
         /* Adds in link to other mount points, that might lie below or
          * above us in the hierarchy */
 
-        LIST_FOREACH(units_per_type, other, UNIT(m)->meta.manager->units_per_type[UNIT_MOUNT]) {
+        LIST_FOREACH(units_per_type, other, u->meta.manager->units_per_type[UNIT_MOUNT]) {
                 Mount *n;
 
                 n = (Mount*) other;
 
-                if (n == m)
+                if (UNIT(n) == u)
                         continue;
 
-                if (m->meta.load_state != UNIT_LOADED)
+                if (u->meta.load_state != UNIT_LOADED)
                         continue;
 
-                if (path_startswith(m->where, n->where)) {
+                if (path_startswith(where, n->where)) {
 
-                        if ((r = unit_add_dependency(UNIT(m), UNIT_AFTER, UNIT(other), true)) < 0)
+                        if ((r = unit_add_dependency(u, UNIT_AFTER, UNIT(other), true)) < 0)
                                 return r;
 
-                        if (n->from_etc_fstab || n->from_fragment)
-                                if ((r = unit_add_dependency(UNIT(m), UNIT_REQUIRES, UNIT(other), true)) < 0)
+                        if (requires)
+                                if ((r = unit_add_dependency(u, UNIT_REQUIRES, UNIT(other), true)) < 0)
                                         return r;
 
-                } else if (path_startswith(n->where, m->where)) {
+                } else if (path_startswith(n->where, where)) {
 
-                        if ((r = unit_add_dependency(UNIT(m), UNIT_BEFORE, UNIT(other), true)) < 0)
+                        if ((r = unit_add_dependency(u, UNIT_BEFORE, UNIT(other), true)) < 0)
                                 return r;
 
-                        if (m->from_etc_fstab || m->from_fragment)
-                                if ((r = unit_add_dependency(UNIT(other), UNIT_REQUIRES, UNIT(m), true)) < 0)
+                        if (requires)
+                                if ((r = unit_add_dependency(UNIT(other), UNIT_REQUIRES, u, true)) < 0)
                                         return r;
                 }
         }
@@ -201,7 +196,7 @@ static int mount_add_path_links(Mount *m) {
         return 0;
 }
 
-static bool mount_test_option(const char *haystack, const char *needle) {
+static char* mount_test_option(const char *haystack, const char *needle) {
         struct mntent me;
 
         assert(needle);
@@ -215,7 +210,7 @@ static bool mount_test_option(const char *haystack, const char *needle) {
         zero(me);
         me.mnt_opts = (char*) haystack;
 
-        return !!hasmntopt(&me, needle);
+        return hasmntopt(&me, needle);
 }
 
 static int mount_add_target_links(Mount *m) {
@@ -234,9 +229,9 @@ static int mount_add_target_links(Mount *m) {
         else
                 return 0;
 
-        noauto = mount_test_option(p->options, MNTOPT_NOAUTO);
-        handle = mount_test_option(p->options, "comment=systemd.mount");
-        automount = mount_test_option(p->options, "comment=systemd.automount");
+        noauto = !!mount_test_option(p->options, MNTOPT_NOAUTO);
+        handle = !!mount_test_option(p->options, "comment=systemd.mount");
+        automount = !!mount_test_option(p->options, "comment=systemd.automount");
 
         if (noauto && !handle && !automount)
                 return 0;
@@ -305,6 +300,9 @@ static int mount_load(Unit *u) {
 
         /* This is a new unit? Then let's add in some extras */
         if (u->meta.load_state == UNIT_LOADED) {
+                const char *what = m->parameters_fragment.what;
+                if (!what)
+                        what = m->parameters_etc_fstab.what;
 
                 if (!m->where)
                         if (!(m->where = unit_name_to_path(u->meta.id)))
@@ -319,10 +317,10 @@ static int mount_load(Unit *u) {
                 if (m->parameters_fragment.what)
                         m->from_fragment = true;
 
-                if ((r = mount_add_node_links(MOUNT(u))) < 0)
+                if ((r = mount_add_node_links(u, what)) < 0)
                         return r;
 
-                if ((r = mount_add_path_links(MOUNT(u))) < 0)
+                if ((r = mount_add_path_links(u, m->where, m->from_etc_fstab || m->from_fragment)) < 0)
                         return r;
 
                 if ((r = mount_add_target_links(MOUNT(u))) < 0)
@@ -1049,9 +1047,9 @@ static int mount_add_one(
                         goto fail;
 
                 if (!(MOUNT(u)->where = strdup(where))) {
-                            r = -ENOMEM;
-                            goto fail;
-                    }
+                        r = -ENOMEM;
+                        goto fail;
+                }
 
                 if ((r = unit_set_description(u, where)) < 0)
                         goto fail;
@@ -1148,6 +1146,27 @@ static char *fstab_node_to_udev_node(char *p) {
         return strdup(p);
 }
 
+static int mount_find_pri(char *options) {
+        char *end, *pri;
+        unsigned long r;
+
+        if (!(pri = mount_test_option(options, "pri=")))
+                return 0;
+
+        pri += 4;
+
+        errno = 0;
+        r = strtoul(pri, &end, 10);
+
+        if (errno != 0)
+                return -errno;
+
+        if (end == pri || (*end != ',' && *end != 0))
+                return -EINVAL;
+
+        return (int) r;
+}
+
 static int mount_load_etc_fstab(Manager *m) {
         FILE *f;
         int r;
@@ -1179,7 +1198,20 @@ static int mount_load_etc_fstab(Manager *m) {
                 if (where[0] == '/')
                         path_kill_slashes(where);
 
-                r = mount_add_one(m, what, where, me->mnt_opts, me->mnt_type, false, false);
+                if (streq(me->mnt_type, "swap")) {
+                        int pri;
+
+                        if ((pri = mount_find_pri(me->mnt_opts)) < 0)
+                                r = pri;
+                        else
+                                r = swap_add_one(m,
+                                                 what,
+                                                 !!mount_test_option(me->mnt_opts, MNTOPT_NOAUTO),
+                                                 pri,
+                                                 false);
+                } else
+                        r = mount_add_one(m, what, where, me->mnt_opts, me->mnt_type, false, false);
+
                 free(what);
                 free(where);
 
diff --git a/mount.h b/mount.h
index 3b28e89ed3..dec1b6478b 100644
--- a/mount.h
+++ b/mount.h
@@ -100,6 +100,8 @@ extern const UnitVTable mount_vtable;
 void mount_fd_event(Manager *m, int events);
 
 int mount_path_is_mounted(Manager *m, const char* path);
+int mount_add_node_links(Unit *m, const char *what);
+int mount_add_path_links(Unit *m, const char *where, bool requires);
 
 const char* mount_state_to_string(MountState i);
 MountState mount_state_from_string(const char *s);
diff --git a/swap.c b/swap.c
new file mode 100644
index 0000000000..aacf0e8d55
--- /dev/null
+++ b/swap.c
@@ -0,0 +1,424 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <limits.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/epoll.h>
+#include <sys/stat.h>
+#include <sys/swap.h>
+
+#include "unit.h"
+#include "swap.h"
+#include "load-fragment.h"
+#include "load-dropin.h"
+#include "unit-name.h"
+#include "dbus-swap.h"
+
+static const UnitActiveState state_translation_table[_SWAP_STATE_MAX] = {
+        [SWAP_DEAD] = UNIT_INACTIVE,
+        [SWAP_ACTIVE] = UNIT_ACTIVE,
+        [SWAP_MAINTAINANCE] = UNIT_INACTIVE
+};
+
+static int swap_verify(Swap *s) {
+        bool b;
+        char *e;
+
+        if (UNIT(s)->meta.load_state != UNIT_LOADED)
+                  return 0;
+
+        if (!(e = unit_name_from_path(s->what, ".swap")))
+                  return -ENOMEM;
+
+        b = unit_has_name(UNIT(s), e);
+        free(e);
+
+        if (!b) {
+                log_error("%s: Value of \"What\" and unit name do not match, not loading.\n", UNIT(s)->meta.id);
+                return -EINVAL;
+        }
+        return 0;
+}
+
+static int swap_add_target_links(Swap *s) {
+        Manager *m = s->meta.manager;
+        Unit *tu;
+        int r;
+
+        r = manager_load_unit(m, SPECIAL_SWAP_TARGET, NULL, &tu);
+        if (r < 0)
+                return r;
+
+        if (!s->no_auto && (r = unit_add_dependency(tu, UNIT_WANTS, UNIT(s), true)) < 0)
+                return r;
+
+        return unit_add_dependency(UNIT(s), UNIT_BEFORE, tu, true);
+}
+
+static int swap_load(Unit *u) {
+        int r;
+        Swap *s = SWAP(u);
+
+        assert(s);
+        assert(u->meta.load_state == UNIT_STUB);
+
+        /* Load a .swap file */
+        if ((r = unit_load_fragment_and_dropin_optional(u)) < 0)
+                return r;
+
+        if (u->meta.load_state == UNIT_LOADED) {
+                if (!s->what)
+                        if (!(s->what = unit_name_to_path(u->meta.id)))
+                                return -ENOMEM;
+
+                path_kill_slashes(s->what);
+
+                if ((r = mount_add_node_links(u, s->what)) < 0)
+                        return r;
+
+                if (!path_startswith(s->what, "/dev/"))
+                        if ((r = mount_add_path_links(u, s->what, true)) < 0)
+                                return r;
+
+                if ((r = swap_add_target_links(s)) < 0)
+                        return r;
+        }
+
+        return swap_verify(s);
+}
+
+int swap_add_one(Manager *m, const char *what, bool no_auto, int prio, bool from_proc_swaps) {
+        Unit *u;
+        char *e;
+        bool delete;
+        int r;
+
+        if (!(e = unit_name_from_path(what, ".swap")))
+                return -ENOMEM;
+
+        if (!(u = manager_get_unit(m, e))) {
+                delete = true;
+
+                if (!(u = unit_new(m))) {
+                        free(e);
+                        return -ENOMEM;
+                }
+
+                r = unit_add_name(u, e);
+                free(e);
+
+                if (r < 0)
+                        goto fail;
+
+                if (!(SWAP(u)->what = strdup(what))) {
+                        r = -ENOMEM;
+                        goto fail;
+                }
+
+                if ((r = unit_set_description(u, what)) < 0)
+                        goto fail;
+
+                unit_add_to_load_queue(u);
+
+                SWAP(u)->from_proc_swaps_only = from_proc_swaps;
+        } else {
+                if (SWAP(u)->from_proc_swaps_only && !from_proc_swaps)
+                        SWAP(u)->from_proc_swaps_only = false;
+
+                delete = false;
+                free(e);
+        }
+
+        if (!from_proc_swaps)
+                SWAP(u)->no_auto = no_auto;
+        else
+                SWAP(u)->found_in_proc_swaps = true;
+
+        SWAP(u)->priority = prio;
+
+        return 0;
+
+fail:
+        if (delete)
+                unit_free(u);
+
+        return 0;
+}
+
+static void swap_set_state(Swap *s, SwapState state) {
+        SwapState old_state;
+        assert(s);
+
+        old_state = s->state;
+        s->state = state;
+
+        if (state != old_state)
+                log_debug("%s changed %s -> %s",
+                          UNIT(s)->meta.id,
+                          swap_state_to_string(old_state),
+                          swap_state_to_string(state));
+
+        unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state]);
+}
+
+static int swap_coldplug(Unit *u) {
+        Swap *s = SWAP(u);
+        SwapState new_state = SWAP_DEAD;
+
+        assert(s);
+        assert(s->state == SWAP_DEAD);
+
+        if (s->deserialized_state != s->state)
+                new_state = s->deserialized_state;
+        else if (s->found_in_proc_swaps)
+                new_state = SWAP_ACTIVE;
+
+        if (new_state != s->state)
+                swap_set_state(s, s->deserialized_state);
+
+        return 0;
+}
+
+static void swap_dump(Unit *u, FILE *f, const char *prefix) {
+        Swap *s = SWAP(u);
+
+        assert(s);
+
+        fprintf(f,
+                "%sAutomount State: %s\n"
+                "%sWhat: %s\n"
+                "%sPriority: %i\n"
+                "%sNoAuto: %s\n",
+                prefix, swap_state_to_string(s->state),
+                prefix, s->what,
+                prefix, s->priority,
+                prefix, yes_no(s->no_auto));
+}
+
+static void swap_enter_dead(Swap *s, bool success) {
+        assert(s);
+
+        swap_set_state(s, success ? SWAP_MAINTAINANCE : SWAP_DEAD);
+}
+
+static int swap_start(Unit *u) {
+        Swap *s = SWAP(u);
+        int r;
+
+        assert(s);
+
+        assert(s->state == SWAP_DEAD || s->state == SWAP_MAINTAINANCE);
+
+        r = swapon(s->what, (s->priority << SWAP_FLAG_PRIO_SHIFT) & SWAP_FLAG_PRIO_MASK);
+
+        if (r < 0 && errno != EBUSY) {
+                r = -errno;
+                swap_enter_dead(s, false);
+                return r;
+        }
+
+        swap_set_state(s, SWAP_ACTIVE);
+        return 0;
+}
+
+static int swap_stop(Unit *u) {
+        Swap *s = SWAP(u);
+        int r;
+
+        assert(s);
+
+        assert(s->state == SWAP_ACTIVE);
+
+        r = swapoff(s->what);
+        swap_enter_dead(s, r >= 0 || errno == EINVAL);
+
+        return 0;
+}
+
+static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
+        Swap *s = SWAP(u);
+
+        assert(s);
+        assert(f);
+        assert(fds);
+
+        unit_serialize_item(u, f, "state", swap_state_to_string(s->state));
+
+        return 0;
+}
+
+static int swap_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
+        Swap *s = SWAP(u);
+
+        assert(s);
+        assert(fds);
+
+        if (streq(key, "state")) {
+                SwapState state;
+
+                if ((state = swap_state_from_string(value)) < 0)
+                        log_debug("Failed to parse state value %s", value);
+                else
+                        s->deserialized_state = state;
+        } else
+                log_debug("Unknown serialization key '%s'", key);
+
+        return 0;
+}
+
+static UnitActiveState swap_active_state(Unit *u) {
+        assert(u);
+
+        return state_translation_table[SWAP(u)->state];
+}
+
+static const char *swap_sub_state_to_string(Unit *u) {
+        assert(u);
+
+        return swap_state_to_string(SWAP(u)->state);
+}
+
+static bool swap_check_gc(Unit *u) {
+        Swap *s = SWAP(u);
+
+        assert(s);
+
+        return !s->from_proc_swaps_only || s->found_in_proc_swaps;
+}
+
+static int swap_load_proc_swaps(Manager *m) {
+        Meta *meta;
+
+        rewind(m->proc_swaps);
+        fscanf(m->proc_self_mountinfo, "%*s %*s %*s %*s %*s\n");
+
+        for (;;) {
+                char *dev = NULL, *d;
+                int prio = 0, k;
+
+                k = fscanf(m->proc_self_mountinfo,
+                           "%ms " /* device/file */
+                           "%*s " /* type of swap */
+                           "%*s " /* swap size */
+                           "%*s " /* used */
+                           "%d\n", /* priority */
+                           &dev, &prio);
+
+                if (k != 2) {
+                        if (k == EOF)
+                                k = 0;
+
+                        free(dev);
+                        return -EBADMSG;
+                }
+                if (!(d = cunescape(dev))) {
+                        free(dev);
+                        k = -ENOMEM;
+                        return k;
+                }
+
+                k = swap_add_one(m, d, false, prio, true);
+                free(dev);
+                free(d);
+
+                if (k < 0)
+                        return k;
+        }
+
+        LIST_FOREACH(units_per_type, meta, m->units_per_type[UNIT_SWAP]) {
+                Swap *s = (Swap*) meta;
+
+                if (s->state != SWAP_DEAD && s->state != SWAP_ACTIVE)
+                        continue;
+
+                if ((s->state == SWAP_DEAD && !s->found_in_proc_swaps) ||
+                    (s->state == SWAP_ACTIVE && s->found_in_proc_swaps))
+                        continue;
+
+                swap_set_state(s, s->found_in_proc_swaps ? SWAP_ACTIVE : SWAP_DEAD);
+
+                /* Reset the flags for later calls */
+                s->found_in_proc_swaps = false;
+        }
+}
+
+static void swap_shutdown(Manager *m) {
+        assert(m);
+
+        if (m->proc_swaps) {
+                fclose(m->proc_swaps);
+                m->proc_swaps = NULL;
+        }
+}
+
+static const char* const swap_state_table[_SWAP_STATE_MAX] = {
+        [SWAP_DEAD] = "dead",
+        [SWAP_ACTIVE] = "active",
+        [SWAP_MAINTAINANCE] = "maintainance"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(swap_state, SwapState);
+
+static int swap_enumerate(Manager *m) {
+        int r;
+        assert(m);
+
+        if (!m->proc_swaps &&
+            !(m->proc_swaps = fopen("/proc/swaps", "er")))
+                return -errno;
+
+        if ((r = swap_load_proc_swaps(m)) < 0)
+                swap_shutdown(m);
+
+        return r;
+}
+
+const UnitVTable swap_vtable = {
+        .suffix = ".swap",
+
+        .no_alias = true,
+        .no_instances = true,
+
+        .load = swap_load,
+
+        .coldplug = swap_coldplug,
+
+        .dump = swap_dump,
+
+        .start = swap_start,
+        .stop = swap_stop,
+
+        .serialize = swap_serialize,
+        .deserialize_item = swap_deserialize_item,
+
+        .active_state = swap_active_state,
+        .sub_state_to_string = swap_sub_state_to_string,
+
+        .check_gc = swap_check_gc,
+
+        .bus_message_handler = bus_swap_message_handler,
+
+        .shutdown = swap_shutdown,
+
+        .enumerate = swap_enumerate
+};
diff --git a/swap.h b/swap.h
new file mode 100644
index 0000000000..d8692509b6
--- /dev/null
+++ b/swap.h
@@ -0,0 +1,60 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+#ifndef fooswaphfoo
+#define fooswaphfoo
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+  Copyright 2010 Maarten Lankhorst
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+typedef struct Swap Swap;
+
+#include "unit.h"
+
+typedef enum SwapState {
+        SWAP_DEAD,
+        SWAP_ACTIVE,
+        SWAP_MAINTAINANCE,
+        _SWAP_STATE_MAX,
+        _SWAP_STATE_INVALID = -1
+} SwapState;
+
+struct Swap {
+        Meta meta;
+
+        char *what;
+
+        int priority;
+
+        bool no_auto;
+
+        bool from_proc_swaps_only:1;
+        bool found_in_proc_swaps:1;
+
+        MountState state, deserialized_state;
+};
+
+extern const UnitVTable swap_vtable;
+
+const char* swap_state_to_string(SwapState i);
+SwapState swap_state_from_string(const char *s);
+
+extern int swap_add_one(Manager *m, const char *what, bool no_auto, int prio, bool from_proc_swap);
+
+#endif
diff --git a/unit.c b/unit.c
index b69b6e3620..dea6b8bf76 100644
--- a/unit.c
+++ b/unit.c
@@ -47,7 +47,8 @@ const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX] = {
         [UNIT_DEVICE] = &device_vtable,
         [UNIT_MOUNT] = &mount_vtable,
         [UNIT_AUTOMOUNT] = &automount_vtable,
-        [UNIT_SNAPSHOT] = &snapshot_vtable
+        [UNIT_SNAPSHOT] = &snapshot_vtable,
+        [UNIT_SWAP] = &swap_vtable
 };
 
 Unit *unit_new(Manager *m) {
@@ -1839,7 +1840,8 @@ static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
         [UNIT_DEVICE] = "device",
         [UNIT_MOUNT] = "mount",
         [UNIT_AUTOMOUNT] = "automount",
-        [UNIT_SNAPSHOT] = "snapshot"
+        [UNIT_SNAPSHOT] = "snapshot",
+        [UNIT_SWAP] = "swap"
 };
 
 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
diff --git a/unit.h b/unit.h
index 689dc00e31..72a742ca4a 100644
--- a/unit.h
+++ b/unit.h
@@ -61,6 +61,7 @@ enum UnitType {
         UNIT_AUTOMOUNT,
         UNIT_SNAPSHOT,
         UNIT_TIMER,
+        UNIT_SWAP,
         _UNIT_TYPE_MAX,
         _UNIT_TYPE_INVALID = -1
 };
@@ -194,6 +195,7 @@ struct Meta {
 #include "mount.h"
 #include "automount.h"
 #include "snapshot.h"
+#include "swap.h"
 
 union Unit {
         Meta meta;
@@ -205,6 +207,7 @@ union Unit {
         Mount mount;
         Automount automount;
         Snapshot snapshot;
+        Swap swap;
 };
 
 struct UnitVTable {
@@ -335,6 +338,7 @@ DEFINE_CAST(DEVICE, Device);
 DEFINE_CAST(MOUNT, Mount);
 DEFINE_CAST(AUTOMOUNT, Automount);
 DEFINE_CAST(SNAPSHOT, Snapshot);
+DEFINE_CAST(SWAP, Swap);
 
 Unit *unit_new(Manager *m);
 void unit_free(Unit *u);