core: rework device state logic

[elogind.git] / src / core / swap.c

diff --git a/src/core/swap.c b/src/core/swap.c
index b97f102d643b7815f135e678bcddc7300353a3b0..de3a5d8b10f1755c23a941bd5e3dae654f569398 100644 (file)
--- a/src/core/swap.c
+++ b/src/core/swap.c
@@ -20,24 +20,17 @@
 ***/
 
 #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 <libudev.h>
 
 #include "unit.h"
 #include "swap.h"
-#include "load-fragment.h"
-#include "load-dropin.h"
 #include "unit-name.h"
 #include "dbus-swap.h"
 #include "special.h"
-#include "bus-common-errors.h"
 #include "exit-status.h"
-#include "def.h"
 #include "path-util.h"
 #include "virt.h"
 #include "udev-util.h"
@@ -338,7 +331,7 @@ static int swap_load(Unit *u) {
         return swap_verify(s);
 }
 
-static int swap_add_one(
+static int swap_setup_unit(
                 Manager *m,
                 const char *what,
                 const char *what_proc_swaps,
@@ -363,8 +356,10 @@ static int swap_add_one(
 
         if (u &&
             SWAP(u)->from_proc_swaps &&
-            !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps))
+            !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps)) {
+                log_error("Swap %s appeared twice with different device paths %s and %s", e, SWAP(u)->parameters_proc_swaps.what, what_proc_swaps);
                 return -EEXIST;
+        }
 
         if (!u) {
                 delete = true;
@@ -379,7 +374,7 @@ static int swap_add_one(
 
                 SWAP(u)->what = strdup(what);
                 if (!SWAP(u)->what) {
-                        r = log_oom();
+                        r = -ENOMEM;
                         goto fail;
                 }
 
@@ -407,7 +402,6 @@ static int swap_add_one(
         p->priority = priority;
 
         unit_add_to_dbus_queue(u);
-
         return 0;
 
 fail:
@@ -419,7 +413,7 @@ fail:
         return r;
 }
 
-static int swap_process_new_swap(Manager *m, const char *device, int prio, bool set_flags) {
+static int swap_process_new(Manager *m, const char *device, int prio, bool set_flags) {
         _cleanup_udev_device_unref_ struct udev_device *d = NULL;
         struct udev_list_entry *item = NULL, *first = NULL;
         const char *dn;
@@ -428,7 +422,7 @@ static int swap_process_new_swap(Manager *m, const char *device, int prio, bool
 
         assert(m);
 
-        r = swap_add_one(m, device, device, prio, set_flags);
+        r = swap_setup_unit(m, device, device, prio, set_flags);
         if (r < 0)
                 return r;
 
@@ -444,7 +438,7 @@ static int swap_process_new_swap(Manager *m, const char *device, int prio, bool
         /* Add the main device node */
         dn = udev_device_get_devnode(d);
         if (dn && !streq(dn, device))
-                swap_add_one(m, dn, device, prio, set_flags);
+                swap_setup_unit(m, dn, device, prio, set_flags);
 
         /* Add additional units for all symlinks */
         first = udev_device_get_devlinks_list_entry(d);
@@ -465,7 +459,7 @@ static int swap_process_new_swap(Manager *m, const char *device, int prio, bool
                             st.st_rdev != udev_device_get_devnum(d))
                                 continue;
 
-                swap_add_one(m, p, device, prio, set_flags);
+                swap_setup_unit(m, p, device, prio, set_flags);
         }
 
         return r;
@@ -473,6 +467,7 @@ static int swap_process_new_swap(Manager *m, const char *device, int prio, bool
 
 static void swap_set_state(Swap *s, SwapState state) {
         SwapState old_state;
+        Swap *other;
 
         assert(s);
 
@@ -500,6 +495,15 @@ static void swap_set_state(Swap *s, SwapState state) {
                                swap_state_to_string(state));
 
         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
+
+        /* If there other units for the same device node have a job
+           queued it might be worth checking again if it is runnable
+           now. This is necessary, since swap_start() refuses
+           operation with EAGAIN if there's already another job for
+           the same device node queued. */
+        LIST_FOREACH_OTHERS(same_devnode, other, s)
+                if (UNIT(other)->job)
+                        job_add_to_run_queue(UNIT(other)->job);
 }
 
 static int swap_coldplug(Unit *u) {
@@ -739,7 +743,7 @@ static void swap_enter_activating(Swap *s) {
                 if (streq(discard, "all"))
                         discard_arg = "--discard";
                 else
-                        discard_arg = strappenda("--discard=", discard);
+                        discard_arg = strjoina("--discard=", discard);
 
                 r = exec_command_append(s->control_command, discard_arg, NULL);
                 if (r < 0)
@@ -796,7 +800,7 @@ fail:
 }
 
 static int swap_start(Unit *u) {
-        Swap *s = SWAP(u);
+        Swap *s = SWAP(u), *other;
 
         assert(s);
 
@@ -818,9 +822,16 @@ static int swap_start(Unit *u) {
         if (detect_container(NULL) > 0)
                 return -EPERM;
 
+        /* If there's a job for another swap unit for the same node
+         * running, then let's not dispatch this one for now, and wait
+         * until that other job has finished. */
+        LIST_FOREACH_OTHERS(same_devnode, other, s)
+                if (UNIT(other)->job && UNIT(other)->job->state == JOB_RUNNING)
+                        return -EAGAIN;
+
         s->result = SWAP_SUCCESS;
         swap_enter_activating(s);
-        return 0;
+        return 1;
 }
 
 static int swap_stop(Unit *u) {
@@ -843,7 +854,7 @@ static int swap_stop(Unit *u) {
                 return -EPERM;
 
         swap_enter_deactivating(s);
-        return 0;
+        return 1;
 }
 
 static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
@@ -1074,15 +1085,17 @@ static int swap_load_proc_swaps(Manager *m, bool set_flags) {
                         if (k == EOF)
                                 break;
 
-                        log_warning("Failed to parse /proc/swaps:%u", i);
+                        log_warning("Failed to parse /proc/swaps:%u.", i);
                         continue;
                 }
 
                 d = cunescape(dev);
                 if (!d)
-                        return -ENOMEM;
+                        return log_oom();
 
-                k = swap_process_new_swap(m, d, prio, set_flags);
+                device_found_node(m, d, true, DEVICE_FOUND_SWAP, set_flags);
+
+                k = swap_process_new(m, d, prio, set_flags);
                 if (k < 0)
                         r = k;
         }
@@ -1134,6 +1147,9 @@ static int swap_dispatch_io(sd_event_source *source, int fd, uint32_t revents, v
                                 break;
                         }
 
+                        if (swap->what)
+                                device_found_node(m, swap->what, false, DEVICE_FOUND_SWAP, true);
+
                 } else if (swap->just_activated) {
 
                         /* New swap entry */
@@ -1281,7 +1297,7 @@ fail:
         return r;
 }
 
-int swap_process_new_device(Manager *m, struct udev_device *dev) {
+int swap_process_device_new(Manager *m, struct udev_device *dev) {
         struct udev_list_entry *item = NULL, *first = NULL;
         _cleanup_free_ char *e = NULL;
         const char *dn;
@@ -1324,7 +1340,7 @@ int swap_process_new_device(Manager *m, struct udev_device *dev) {
         return r;
 }
 
-int swap_process_removed_device(Manager *m, struct udev_device *dev) {
+int swap_process_device_remove(Manager *m, struct udev_device *dev) {
         const char *dn;
         int r = 0;
         Swap *s;