[systemd-devel] [PATCH] swap: rework discard
Jan Synacek
jsynacek at redhat.com
Thu Oct 23 05:58:13 PDT 2014
Instead of a dedicated Discard option, use more general Options. When
the swapon command learns "-o", it will be possible to pass the value of
Options as is. The code now assumes that the only possible value to
Options is related to discard.
http://lists.freedesktop.org/archives/systemd-devel/2014-October/024132.html
---
src/core/dbus-swap.c | 8 +++----
src/core/load-fragment-gperf.gperf.m4 | 2 +-
src/core/swap.c | 28 +++++++++++-----------
src/core/swap.h | 3 ++-
src/fstab-generator/fstab-generator.c | 44 +++--------------------------------
5 files changed, 25 insertions(+), 60 deletions(-)
diff --git a/src/core/dbus-swap.c b/src/core/dbus-swap.c
index c854716..0792cb4 100644
--- a/src/core/dbus-swap.c
+++ b/src/core/dbus-swap.c
@@ -55,7 +55,7 @@ static int property_get_priority(
return sd_bus_message_append(reply, "i", p);
}
-static int property_get_discard(
+static int property_get_options(
sd_bus *bus,
const char *path,
const char *interface,
@@ -72,9 +72,9 @@ static int property_get_discard(
assert(s);
if (s->from_fragment)
- p = s->parameters_fragment.discard ?: "none";
+ p = s->parameters_fragment.options ?: "";
else
- p = "none";
+ p = "";
return sd_bus_message_append(reply, "s", p);
}
@@ -84,7 +84,7 @@ const sd_bus_vtable bus_swap_vtable[] = {
SD_BUS_VTABLE_START(0),
SD_BUS_PROPERTY("What", "s", NULL, offsetof(Swap, what), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
SD_BUS_PROPERTY("Priority", "i", property_get_priority, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
- SD_BUS_PROPERTY("Discard", "s", property_get_discard, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
+ SD_BUS_PROPERTY("Options", "s", property_get_options, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
SD_BUS_PROPERTY("TimeoutUSec", "t", bus_property_get_usec, offsetof(Swap, timeout_usec), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("ControlPID", "u", bus_property_get_pid, offsetof(Swap, control_pid), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
SD_BUS_PROPERTY("Result", "s", property_get_result, offsetof(Swap, result), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index 8805411..19a79d5 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -297,7 +297,7 @@ Automount.DirectoryMode, config_parse_mode, 0,
m4_dnl
Swap.What, config_parse_path, 0, offsetof(Swap, parameters_fragment.what)
Swap.Priority, config_parse_int, 0, offsetof(Swap, parameters_fragment.priority)
-Swap.Discard, config_parse_string, 0, offsetof(Swap, parameters_fragment.discard)
+Swap.Options, config_parse_string, 0, offsetof(Swap, parameters_fragment.options)
Swap.TimeoutSec, config_parse_sec, 0, offsetof(Swap, timeout_usec)
EXEC_CONTEXT_CONFIG_ITEMS(Swap)m4_dnl
CGROUP_CONTEXT_CONFIG_ITEMS(Swap)m4_dnl
diff --git a/src/core/swap.c b/src/core/swap.c
index b2ca048..c183c32 100644
--- a/src/core/swap.c
+++ b/src/core/swap.c
@@ -152,8 +152,8 @@ static void swap_done(Unit *u) {
free(s->parameters_fragment.what);
s->parameters_fragment.what = NULL;
- free(s->parameters_fragment.discard);
- s->parameters_fragment.discard = NULL;
+ free(s->parameters_fragment.options);
+ s->parameters_fragment.options = NULL;
s->exec_runtime = exec_runtime_unref(s->exec_runtime);
exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);
@@ -607,12 +607,15 @@ static void swap_dump(Unit *u, FILE *f, const char *prefix) {
fprintf(f,
"%sPriority: %i\n"
"%sNoAuto: %s\n"
- "%sNoFail: %s\n"
- "%sDiscard: %s\n",
+ "%sNoFail: %s\n",
prefix, p->priority,
prefix, yes_no(p->noauto),
- prefix, yes_no(p->nofail),
- prefix, p->discard ?: "none");
+ prefix, yes_no(p->nofail));
+
+ if (p->options)
+ fprintf(f,
+ "%sOptions: %s\n",
+ prefix, p->options);
if (s->control_pid > 0)
fprintf(f,
@@ -741,7 +744,7 @@ fail:
static void swap_enter_activating(Swap *s) {
int r, priority;
- char *discard;
+ char *discard = NULL;
assert(s);
@@ -750,7 +753,8 @@ static void swap_enter_activating(Swap *s) {
if (s->from_fragment) {
priority = s->parameters_fragment.priority;
- discard = s->parameters_fragment.discard;
+ if (s->parameters_fragment.options)
+ discard = strstr(s->parameters_fragment.options, "discard");
} else {
priority = -1;
discard = NULL;
@@ -769,12 +773,10 @@ static void swap_enter_activating(Swap *s) {
goto fail;
}
- if (discard && !streq(discard, "none")) {
- const char *discard_arg = "--discard";
-
- if (!streq(discard, "all"))
- discard_arg = strappenda("--discard=", discard);
+ if (discard) {
+ char *discard_arg;
+ discard_arg = strappenda("--", discard);
r = exec_command_append(s->control_command, discard_arg, NULL);
if (r < 0)
goto fail;
diff --git a/src/core/swap.h b/src/core/swap.h
index 3482d65..f5809a1 100644
--- a/src/core/swap.h
+++ b/src/core/swap.h
@@ -63,7 +63,8 @@ typedef enum SwapResult {
typedef struct SwapParameters {
char *what;
- char *discard;
+ char *options;
+ /* XXX: Once swapon learns "-o", priority can fall under options as well. */
int priority;
bool noauto:1;
bool nofail:1;
diff --git a/src/fstab-generator/fstab-generator.c b/src/fstab-generator/fstab-generator.c
index 32a8f9b..6485949 100644
--- a/src/fstab-generator/fstab-generator.c
+++ b/src/fstab-generator/fstab-generator.c
@@ -76,43 +76,10 @@ static int mount_find_pri(struct mntent *me, int *ret) {
return 1;
}
-static int mount_find_discard(struct mntent *me, char **ret) {
- char *opt, *ans;
- size_t len;
-
- assert(me);
- assert(ret);
-
- opt = hasmntopt(me, "discard");
- if (!opt)
- return 0;
-
- opt += strlen("discard");
-
- if (*opt == ',' || *opt == '\0')
- ans = strdup("all");
- else {
- if (*opt != '=')
- return -EINVAL;
-
- len = strcspn(opt + 1, ",");
- if (len == 0)
- return -EINVAL;
-
- ans = strndup(opt + 1, len);
- }
-
- if (!ans)
- return -ENOMEM;
-
- *ret = ans;
- return 1;
-}
-
static int add_swap(const char *what, struct mntent *me) {
_cleanup_free_ char *name = NULL, *unit = NULL, *lnk = NULL;
_cleanup_fclose_ FILE *f = NULL;
- _cleanup_free_ char *discard = NULL;
+ char *discard;
bool noauto;
int r, pri = -1;
@@ -131,13 +98,8 @@ static int add_swap(const char *what, struct mntent *me) {
return r;
}
- r = mount_find_discard(me, &discard);
- if (r < 0) {
- log_error("Failed to parse discard");
- return r;
- }
-
noauto = !!hasmntopt(me, "noauto");
+ discard = hasmntopt(me, "discard");
name = unit_name_from_path(what, ".swap");
if (!name)
@@ -169,7 +131,7 @@ static int add_swap(const char *what, struct mntent *me) {
fprintf(f, "Priority=%i\n", pri);
if (discard)
- fprintf(f, "Discard=%s\n", discard);
+ fprintf(f, "Options=%s\n", discard);
fflush(f);
if (ferror(f)) {
--
1.9.3
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