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systemd-sleep: use swaps in priority order 

In situations where hibernation is requested but resume= and
resume_offset= kernel parameters are not configured, systemd
will attempt to locate a suitable swap location by inspecting
/proc/swaps. This change will use the first suitable swap with
the highest configured priority.
This commit is contained in:
Zach Smith 2019-07-14 20:01:20 -07:00 committed by Lennart Poettering
parent a18a3aacd3
commit 88bc86fcf8
3 changed files with 67 additions and 33 deletions
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2
TODO
View File

@ -626,8 +626,6 @@ Features:
* transient units:
- add field to transient units that indicate whether systemd or somebody else saves/restores its settings, for integration with libvirt
* Automatically configure swap partition to use for hibernation by looking for largest swap partition on the root disk?
* when we detect low battery and no AC on boot, show pretty splash and refuse boot
* libsystemd-journal, libsystemd-login, libudev: add calls to easily attach these objects to sd-event event loops

96
src/shared/sleep-config.c
View File

@ -165,8 +165,30 @@ int can_sleep_disk(char **types) {
#define HIBERNATION_SWAP_THRESHOLD 0.98
int find_hibernate_location(char **device, char **type, size_t *size, size_t *used) {
/* entry in /proc/swaps */
typedef struct SwapEntry {
char *device;
char *type;
uint64_t size;
uint64_t used;
int priority;
} SwapEntry;
static SwapEntry* swap_entry_free(SwapEntry *se) {
if (!se)
return NULL;
free(se->device);
free(se->type);
return mfree(se);
}
DEFINE_TRIVIAL_CLEANUP_FUNC(SwapEntry*, swap_entry_free);
int find_hibernate_location(char **device, char **type, uint64_t *size, uint64_t *used) {
_cleanup_fclose_ FILE *f;
_cleanup_(swap_entry_freep) SwapEntry *selected_swap = NULL;
unsigned i;
f = fopen("/proc/swaps", "re");
@ -178,62 +200,76 @@ int find_hibernate_location(char **device, char **type, size_t *size, size_t *us
(void) fscanf(f, "%*s %*s %*s %*s %*s\n");
// TODO: sort swaps in priority order rather than using first successful option
for (i = 1;; i++) {
_cleanup_free_ char *dev_field = NULL, *type_field = NULL;
size_t size_field, used_field;
_cleanup_(swap_entry_freep) SwapEntry *swap = NULL;
int k;
swap = new0(SwapEntry, 1);
if (!swap)
return log_oom();
k = fscanf(f,
"%ms " /* device/file */
"%ms " /* type of swap */
"%zu " /* swap size */
"%zu " /* used */
"%*i\n", /* priority */
&dev_field, &type_field, &size_field, &used_field);
"%ms " /* device/file */
"%ms " /* type of swap */
"%" PRIu64 /* swap size */
"%" PRIu64 /* used */
"%i\n", /* priority */
&swap->device, &swap->type, &swap->size, &swap->used, &swap->priority);
if (k == EOF)
break;
if (k != 4) {
if (k != 5) {
log_warning("Failed to parse /proc/swaps:%u", i);
continue;
}
if (streq(type_field, "file")) {
if (streq(swap->type, "file")) {
if (endswith(dev_field, "\\040(deleted)")) {
log_warning("Ignoring deleted swap file '%s'.", dev_field);
if (endswith(swap->device, "\\040(deleted)")) {
log_warning("Ignoring deleted swap file '%s'.", swap->device);
continue;
}
} else if (streq(type_field, "partition")) {
} else if (streq(swap->type, "partition")) {
const char *fn;
fn = path_startswith(dev_field, "/dev/");
fn = path_startswith(swap->device, "/dev/");
if (fn && startswith(fn, "zram")) {
log_debug("Ignoring compressed RAM swap device '%s'.", dev_field);
log_debug("Ignoring compressed RAM swap device '%s'.", swap->device);
continue;
}
}
if (device)
*device = TAKE_PTR(dev_field);
if (type)
*type = TAKE_PTR(type_field);
if (size)
*size = size_field;
if (used)
*used = used_field;
return 0;
/* prefer highest priority or swap with most remaining space when same priority */
if (!selected_swap || swap->priority > selected_swap->priority
|| ((swap->priority == selected_swap->priority)
&& (swap->size - swap->used) > (selected_swap->size - selected_swap->used))) {
selected_swap = swap_entry_free(selected_swap);
selected_swap = TAKE_PTR(swap);
}
}
return log_debug_errno(SYNTHETIC_ERRNO(ENOSYS),
"No swap partitions were found.");
if (!selected_swap)
return log_debug_errno(SYNTHETIC_ERRNO(ENOSYS), "No swap partitions or files were found.");
/* use the swap entry with the highest priority */
if (device)
*device = TAKE_PTR(selected_swap->device);
if (type)
*type = TAKE_PTR(selected_swap->type);
if (size)
*size = selected_swap->size;
if (used)
*used = selected_swap->used;
log_debug("Highest priority swap entry found %s: %i", selected_swap->device, selected_swap->priority);
return 0;
}
static bool enough_swap_for_hibernation(void) {
_cleanup_free_ char *active = NULL;
unsigned long long act = 0;
size_t size = 0, used = 0;
uint64_t size = 0, used = 0;
int r;
if (getenv_bool("SYSTEMD_BYPASS_HIBERNATION_MEMORY_CHECK") > 0)
@ -256,7 +292,7 @@ static bool enough_swap_for_hibernation(void) {
}
r = act <= (size - used) * HIBERNATION_SWAP_THRESHOLD;
log_debug("%s swap for hibernation, Active(anon)=%llu kB, size=%zu kB, used=%zu kB, threshold=%.2g%%",
log_debug("%s swap for hibernation, Active(anon)=%llu kB, size=%" PRIu64 " kB, used=%" PRIu64 " kB, threshold=%.2g%%",
r ? "Enough" : "Not enough", act, size, used, 100*HIBERNATION_SWAP_THRESHOLD);
return r;

2
src/shared/sleep-config.h
View File

@ -27,7 +27,7 @@ int sleep_settings(const char *verb, const SleepConfig *sleep_config, bool *ret_
int read_fiemap(int fd, struct fiemap **ret);
int parse_sleep_config(SleepConfig **sleep_config);
int find_hibernate_location(char **device, char **type, size_t *size, size_t *used);
int find_hibernate_location(char **device, char **type, uint64_t *size, uint64_t *used);
int can_sleep(const char *verb);
int can_sleep_disk(char **types);