init: Add support for specifying a services i/o priority

Signed-off-by: San Mehat <san@google.com>
diff --git a/init/init.c b/init/init.c
index 16a3530..4d98cc2 100755
--- a/init/init.c
+++ b/init/init.c
@@ -35,6 +35,7 @@
 #include <sys/reboot.h>
 
 #include <cutils/sockets.h>
+#include <cutils/iosched_policy.h>
 #include <termios.h>
 #include <linux/kd.h>
 #include <linux/keychord.h>
@@ -224,6 +225,13 @@
             }
         }
 
+        if (svc->ioprio_class != IoSchedClass_NONE) {
+            if (android_set_ioprio(getpid(), svc->ioprio_class, svc->ioprio_pri)) {
+                ERROR("Failed to set pid %d ioprio = %d,%d: %s\n",
+                      getpid(), svc->ioprio_class, svc->ioprio_pri, strerror(errno));
+            }
+        }
+
         if (needs_console) {
             setsid();
             open_console();
diff --git a/init/init.h b/init/init.h
index 60c3055..8c0571c 100644
--- a/init/init.h
+++ b/init/init.h
@@ -146,6 +146,9 @@
     int nkeycodes;
     int keychord_id;
 
+    int ioprio_class;
+    int ioprio_pri;
+
     int nargs;
     /* "MUST BE AT THE END OF THE STRUCT" */
     char *args[1];
diff --git a/init/keywords.h b/init/keywords.h
index 308118e..254c785 100644
--- a/init/keywords.h
+++ b/init/keywords.h
@@ -75,6 +75,7 @@
     KEYWORD(chmod,       COMMAND, 2, do_chmod)
     KEYWORD(loglevel,    COMMAND, 1, do_loglevel)
     KEYWORD(device,      COMMAND, 4, do_device)
+    KEYWORD(ioprio,      OPTION,  0, 0)
 #ifdef __MAKE_KEYWORD_ENUM__
     KEYWORD_COUNT,
 };
diff --git a/init/parser.c b/init/parser.c
index 54622cc..7da0d19 100644
--- a/init/parser.c
+++ b/init/parser.c
@@ -10,6 +10,8 @@
 #include "init.h"
 #include "property_service.h"
 
+#include <cutils/iosched_policy.h>
+
 #define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
 #include <sys/_system_properties.h>
 
@@ -155,6 +157,7 @@
         if (!strcmp(s, "ostname")) return K_hostname;
         break;
     case 'i':
+        if (!strcmp(s, "oprio")) return K_ioprio;
         if (!strcmp(s, "fup")) return K_ifup;
         if (!strcmp(s, "nsmod")) return K_insmod;
         if (!strcmp(s, "mport")) return K_import;
@@ -619,6 +622,8 @@
         return;
     }
     
+    svc->ioprio_class = IoSchedClass_NONE;
+
     kw = lookup_keyword(args[0]);
     switch (kw) {
     case K_capability:
@@ -636,6 +641,28 @@
     case K_disabled:
         svc->flags |= SVC_DISABLED;
         break;
+    case K_ioprio:
+        if (nargs != 3) {
+            parse_error(state, "ioprio optin usage: ioprio <rt|be|idle> <ioprio 0-7>\n");
+        } else {
+            svc->ioprio_pri = strtoul(args[2], 0, 8);
+
+            if (svc->ioprio_pri < 0 || svc->ioprio_pri > 7) {
+                parse_error(state, "priority value must be range 0 - 7\n");
+                break;
+            }
+
+            if (!strcmp(args[1], "rt")) {
+                svc->ioprio_class = IoSchedClass_RT;
+            } else if (!strcmp(args[1], "be")) {
+                svc->ioprio_class = IoSchedClass_BE;
+            } else if (!strcmp(args[1], "idle")) {
+                svc->ioprio_class = IoSchedClass_IDLE;
+            } else {
+                parse_error(state, "ioprio option usage: ioprio <rt|be|idle> <0-7>\n");
+            }
+        }
+        break;
     case K_group:
         if (nargs < 2) {
             parse_error(state, "group option requires a group id\n");