manager: introduce unit path cache to minimize disk accesses

[elogind.git] / src / manager.c

diff --git a/src/manager.c b/src/manager.c
index bd4f4659afb77c1fc0ded97f07f645cd489b3435..5125db2e9a4f1af68d1e7fd5ea30d01fa260884c 100644 (file)
--- a/src/manager.c
+++ b/src/manager.c
@@ -36,6 +36,7 @@
 #include <fcntl.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <sys/types.h>
 #include <sys/stat.h>

+#include <dirent.h>

 
 #include "manager.h"
 #include "hashmap.h"
 
 #include "manager.h"
 #include "hashmap.h"


@@ -186,7 +187,6 @@ static int manager_setup_signals(Manager *m) {
 int manager_new(ManagerRunningAs running_as, Manager **_m) {
         Manager *m;
         int r = -ENOMEM;
 int manager_new(ManagerRunningAs running_as, Manager **_m) {
         Manager *m;
         int r = -ENOMEM;

-        char *p;

 
         assert(_m);
         assert(running_as >= 0);
 
         assert(_m);
         assert(running_as >= 0);


@@ -245,14 +245,6 @@ int manager_new(ManagerRunningAs running_as, Manager **_m) {
         if ((r = bus_init(m)) < 0)
                 goto fail;
 
         if ((r = bus_init(m)) < 0)
                 goto fail;
 

-        if (asprintf(&p, "%s/%s", m->cgroup_mount_point, m->cgroup_hierarchy) < 0) {
-                r = -ENOMEM;
-                goto fail;
-        }
-
-        m->pin_cgroupfs_fd = open(p, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK);
-        free(p);
-

         *_m = m;
         return 0;
 
         *_m = m;
         return 0;
 


@@ -420,8 +412,7 @@ void manager_free(Manager *m) {
 
         /* If we reexecute ourselves, we keep the root cgroup
          * around */
 
         /* If we reexecute ourselves, we keep the root cgroup
          * around */

-        if (m->exit_code != MANAGER_REEXECUTE)
-                manager_shutdown_cgroup(m);
+        manager_shutdown_cgroup(m, m->exit_code != MANAGER_REEXECUTE);

 
         bus_done(m);
 
 
         bus_done(m);
 


@@ -443,14 +434,8 @@ void manager_free(Manager *m) {
         lookup_paths_free(&m->lookup_paths);
         strv_free(m->environment);
 
         lookup_paths_free(&m->lookup_paths);
         strv_free(m->environment);
 

-        free(m->cgroup_controller);
-        free(m->cgroup_hierarchy);
-        free(m->cgroup_mount_point);
-

         hashmap_free(m->cgroup_bondings);
         hashmap_free(m->cgroup_bondings);

-
-        if (m->pin_cgroupfs_fd >= 0)
-                close_nointr_nofail(m->pin_cgroupfs_fd);
+        set_free_free(m->unit_path_cache);

 
         free(m);
 }
 
         free(m);
 }


@@ -494,11 +479,71 @@ int manager_coldplug(Manager *m) {
         return r;
 }
 
         return r;
 }
 

+static void manager_build_unit_path_cache(Manager *m) {
+        char **i;
+        DIR *d = NULL;
+        int r;
+
+        assert(m);
+
+        set_free_free(m->unit_path_cache);
+
+        if (!(m->unit_path_cache = set_new(string_hash_func, string_compare_func))) {
+                log_error("Failed to allocate unit path cache.");
+                return;
+        }
+
+        /* This simply builds a list of files we know exist, so that
+         * we don't always have to go to disk */
+
+        STRV_FOREACH(i, m->lookup_paths.unit_path) {
+                struct dirent *de;
+
+                if (!(d = opendir(*i))) {
+                        log_error("Failed to open directory: %m");
+                        continue;
+                }
+
+                while ((de = readdir(d))) {
+                        char *p;
+
+                        if (ignore_file(de->d_name))
+                                continue;
+
+                        if (asprintf(&p, "%s/%s", streq(*i, "/") ? "" : *i, de->d_name) < 0) {
+                                r = -ENOMEM;
+                                goto fail;
+                        }
+
+                        if ((r = set_put(m->unit_path_cache, p)) < 0) {
+                                free(p);
+                                goto fail;
+                        }
+                }
+
+                closedir(d);
+                d = NULL;
+        }
+
+        return;
+
+fail:
+        log_error("Failed to build unit path cache: %s", strerror(-r));
+
+        set_free_free(m->unit_path_cache);
+        m->unit_path_cache = NULL;
+
+        if (d)
+                closedir(d);
+}
+

 int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
         int r, q;
 
         assert(m);
 
 int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
         int r, q;
 
         assert(m);
 

+        manager_build_unit_path_cache(m);
+

         /* First, enumerate what we can from all config files */
         r = manager_enumerate(m);
 
         /* First, enumerate what we can from all config files */
         r = manager_enumerate(m);
 


@@ -1665,7 +1710,7 @@ static int manager_process_notify_fd(Manager *m) {
 
                 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
 
 
                 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
 

-                if (!(u = hashmap_get(m->watch_pids, UINT32_TO_PTR(ucred->pid))))
+                if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(ucred->pid))))

                         if (!(u = cgroup_unit_by_pid(m, ucred->pid))) {
                                 log_warning("Cannot find unit for notify message of PID %lu.", (unsigned long) ucred->pid);
                                 continue;
                         if (!(u = cgroup_unit_by_pid(m, ucred->pid))) {
                                 log_warning("Cannot find unit for notify message of PID %lu.", (unsigned long) ucred->pid);
                                 continue;


@@ -1730,7 +1775,7 @@ static int manager_dispatch_sigchld(Manager *m) {
                         return r;
 
                 /* And now figure out the unit this belongs to */
                         return r;
 
                 /* And now figure out the unit this belongs to */

-                if (!(u = hashmap_get(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
+                if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(si.si_pid))))

                         u = cgroup_unit_by_pid(m, si.si_pid);
 
                 /* And now, we actually reap the zombie. */
                         u = cgroup_unit_by_pid(m, si.si_pid);
 
                 /* And now, we actually reap the zombie. */


@@ -1748,14 +1793,14 @@ static int manager_dispatch_sigchld(Manager *m) {
                           (long unsigned) si.si_pid,
                           sigchld_code_to_string(si.si_code),
                           si.si_status,
                           (long unsigned) si.si_pid,
                           sigchld_code_to_string(si.si_code),
                           si.si_status,

-                          strna(si.si_code == CLD_EXITED ? exit_status_to_string(si.si_status) : strsignal(si.si_status)));
+                          strna(si.si_code == CLD_EXITED ? exit_status_to_string(si.si_status) : signal_to_string(si.si_status)));

 
                 if (!u)
                         continue;
 
 
                 if (!u)
                         continue;
 

-                log_debug("Child %llu belongs to %s", (long long unsigned) si.si_pid, u->meta.id);
+                log_debug("Child %lu belongs to %s", (long unsigned) si.si_pid, u->meta.id);

 
 

-                hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid));
+                hashmap_remove(m->watch_pids, LONG_TO_PTR(si.si_pid));

                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
         }
 
                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
         }
 


@@ -2009,6 +2054,10 @@ int manager_loop(Manager *m) {
         assert(m);
         m->exit_code = MANAGER_RUNNING;
 
         assert(m);
         m->exit_code = MANAGER_RUNNING;
 

+        /* Release the path cache */
+        set_free_free(m->unit_path_cache);
+        m->unit_path_cache = NULL;
+

         /* There might still be some zombies hanging around from
          * before we were exec()'ed. Leat's reap them */
         if ((r = manager_dispatch_sigchld(m)) < 0)
         /* There might still be some zombies hanging around from
          * before we were exec()'ed. Leat's reap them */
         if ((r = manager_dispatch_sigchld(m)) < 0)