X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=swap.c;fp=swap.c;h=aacf0e8d554ba107f2e577202f9fc4dfcb8178dc;hb=07b0b134d3076fe223d6e15959b6081a74b56792;hp=0000000000000000000000000000000000000000;hpb=af5bc85dc1297079edc9890861aaa38de0ec30df;p=elogind.git

diff --git a/swap.c b/swap.c
new file mode 100644
index 000000000..aacf0e8d5
--- /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
+};