diff options
Diffstat (limited to 'src/swap.c')
| -rw-r--r-- | src/swap.c | 578 |
1 files changed, 578 insertions, 0 deletions
diff --git a/src/swap.c b/src/swap.c new file mode 100644 index 0000000000..bd49e1ea2b --- /dev/null +++ b/src/swap.c @@ -0,0 +1,578 @@ +/*-*- 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 void swap_init(Unit *u) { + Swap *s = SWAP(u); + + assert(s); + assert(s->meta.load_state == UNIT_STUB); + + s->parameters_etc_fstab.priority = s->parameters_proc_swaps.priority = s->parameters_fragment.priority = -1; +} + +static void swap_done(Unit *u) { + Swap *s = SWAP(u); + + assert(s); + + free(s->what); + free(s->parameters_etc_fstab.what); + free(s->parameters_proc_swaps.what); + free(s->parameters_fragment.what); +} + +int swap_add_one_mount_link(Swap *s, Mount *m) { + int r; + + assert(s); + assert(m); + + if (s->meta.load_state != UNIT_LOADED || + m->meta.load_state != UNIT_LOADED) + return 0; + + if (is_device_path(s->what)) + return 0; + + if (!path_startswith(s->what, m->where)) + return 0; + + if ((r = unit_add_dependency(UNIT(m), UNIT_BEFORE, UNIT(s), true)) < 0) + return r; + + if ((r = unit_add_dependency(UNIT(s), UNIT_REQUIRES, UNIT(m), true)) < 0) + return r; + + return 0; +} + +static int swap_add_mount_links(Swap *s) { + Meta *other; + int r; + + assert(s); + + LIST_FOREACH(units_per_type, other, s->meta.manager->units_per_type[UNIT_MOUNT]) + if ((r = swap_add_one_mount_link(s, (Mount*) other)) < 0) + return r; + + return 0; +} + +static int swap_add_target_links(Swap *s) { + Unit *tu; + SwapParameters *p; + int r; + + assert(s); + + if (s->from_fragment) + p = &s->parameters_fragment; + else if (s->from_etc_fstab) + p = &s->parameters_etc_fstab; + else + return 0; + + if ((r = manager_load_unit(s->meta.manager, SPECIAL_SWAP_TARGET, NULL, &tu)) < 0) + return r; + + if (!p->noauto && p->handle) + if ((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_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_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->meta.fragment_path) + s->from_fragment = true; + + if (!s->what) { + if (s->parameters_fragment.what) + s->what = strdup(s->parameters_fragment.what); + else if (s->parameters_etc_fstab.what) + s->what = strdup(s->parameters_etc_fstab.what); + else if (s->parameters_proc_swaps.what) + s->what = strdup(s->parameters_proc_swaps.what); + else + s->what = unit_name_to_path(u->meta.id); + + if (!s->what) + return -ENOMEM; + } + + path_kill_slashes(s->what); + + if (!s->meta.description) + if ((r = unit_set_description(u, s->what)) < 0) + return r; + + if ((r = unit_add_node_link(u, s->what, + (u->meta.manager->running_as == MANAGER_INIT || + u->meta.manager->running_as == MANAGER_SYSTEM))) < 0) + return r; + + if ((r = swap_add_mount_links(s)) < 0) + return r; + + if ((r = swap_add_target_links(s)) < 0) + return r; + } + + return swap_verify(s); +} + +static int swap_find(Manager *m, const char *what, Unit **_u) { + Unit *u; + char *e; + + assert(m); + assert(what); + assert(_u); + + /* /proc/swaps and /etc/fstab might refer to this device by + * different names (e.g. one by uuid, the other by the kernel + * name), we hence need to look for all aliases we are aware + * of for this device */ + + if (!(e = unit_name_from_path(what, ".device"))) + return -ENOMEM; + + u = manager_get_unit(m, e); + free(e); + + if (u) { + Iterator i; + const char *d; + + SET_FOREACH(d, u->meta.names, i) { + Unit *k; + + if (!(e = unit_name_change_suffix(d, ".swap"))) + return -ENOMEM; + + k = manager_get_unit(m, e); + free(e); + + if (k) { + *_u = k; + return 0; + } + } + } + + *_u = NULL; + return 0; +} + +int swap_add_one( + Manager *m, + const char *what, + int priority, + bool noauto, + bool handle, + bool from_proc_swaps) { + Unit *u = NULL; + char *e = NULL, *w = NULL; + bool delete; + int r; + SwapParameters *p; + + assert(m); + assert(what); + + if (!(e = unit_name_from_path(what, ".swap"))) + return -ENOMEM; + + if (!(u = manager_get_unit(m, e))) + if ((r = swap_find(m, what, &u)) < 0) + goto fail; + + if (!u) { + delete = true; + + if (!(u = unit_new(m))) { + free(e); + return -ENOMEM; + } + } else + delete = false; + + if ((r = unit_add_name(u, e)) < 0) + goto fail; + + if (!(w = strdup(what))) { + r = -ENOMEM; + goto fail; + } + + if (from_proc_swaps) { + p = &SWAP(u)->parameters_proc_swaps; + SWAP(u)->from_proc_swaps = true; + } else { + p = &SWAP(u)->parameters_etc_fstab; + SWAP(u)->from_etc_fstab = true; + } + + free(p->what); + p->what = w; + + p->priority = priority; + p->noauto = noauto; + p->handle = handle; + + if (delete) + unit_add_to_load_queue(u); + + unit_add_to_dbus_queue(u); + + free(e); + + return 0; + +fail: + free(w); + free(e); + + if (delete && u) + unit_free(u); + + return r; +} + +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->from_proc_swaps) + new_state = SWAP_ACTIVE; + + if (new_state != s->state) + swap_set_state(s, new_state); + + return 0; +} + +static void swap_dump(Unit *u, FILE *f, const char *prefix) { + Swap *s = SWAP(u); + SwapParameters *p; + + assert(s); + assert(f); + + if (s->from_proc_swaps) + p = &s->parameters_proc_swaps; + else if (s->from_fragment) + p = &s->parameters_fragment; + else + p = &s->parameters_etc_fstab; + + fprintf(f, + "%sSwap State: %s\n" + "%sWhat: %s\n" + "%sPriority: %i\n" + "%sNoAuto: %s\n" + "%sHandle: %s\n" + "%sFrom /etc/fstab: %s\n" + "%sFrom /proc/swaps: %s\n" + "%sFrom fragment: %s\n", + prefix, swap_state_to_string(s->state), + prefix, s->what, + prefix, p->priority, + prefix, yes_no(p->noauto), + prefix, yes_no(p->handle), + prefix, yes_no(s->from_etc_fstab), + prefix, yes_no(s->from_proc_swaps), + prefix, yes_no(s->from_fragment)); +} + +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 priority = -1; + int r; + + assert(s); + assert(s->state == SWAP_DEAD || s->state == SWAP_MAINTAINANCE); + + if (s->from_fragment) + priority = s->parameters_fragment.priority; + else if (s->from_etc_fstab) + priority = s->parameters_etc_fstab.priority; + + r = swapon(s->what, (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_etc_fstab || s->from_proc_swaps; +} + +static int swap_load_proc_swaps(Manager *m) { + rewind(m->proc_swaps); + + (void) fscanf(m->proc_swaps, "%*s %*s %*s %*s %*s\n"); + + for (;;) { + char *dev = NULL, *d; + int prio = 0, k; + + if ((k = fscanf(m->proc_swaps, + "%ms " /* device/file */ + "%*s " /* type of swap */ + "%*s " /* swap size */ + "%*s " /* used */ + "%i\n", /* priority */ + &dev, &prio)) != 2) { + + if (k == EOF) + break; + + free(dev); + return -EBADMSG; + } + + d = cunescape(dev); + free(dev); + + if (!d) + return -ENOMEM; + + k = swap_add_one(m, d, prio, false, false, true); + free(d); + + if (k < 0) + return k; + } + + return 0; +} + +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) + if (!(m->proc_swaps = fopen("/proc/swaps", "re"))) + return -errno; + + if ((r = swap_load_proc_swaps(m)) < 0) + swap_shutdown(m); + + return r; +} + +const UnitVTable swap_vtable = { + .suffix = ".swap", + + .no_instances = true, + .no_isolate = true, + + .init = swap_init, + .load = swap_load, + .done = swap_done, + + .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, + + .enumerate = swap_enumerate, + .shutdown = swap_shutdown +}; |