ionice: new applet, adapted from Linux kernel' example by Walter Harms

   text    data     bss     dec     hex filename
1050316     924   10952 1062192  103530 busybox_old
1050758     924   10952 1062634  1036ea busybox_unstripped

3 files changed, 107 insertions, 0 deletions

diff --git a/miscutils/Config.in b/miscutils/Config.in
index 68732e682..94174de3e 100644
--- a/miscutils/Config.in
+++ b/miscutils/Config.in
@@ -238,6 +238,13 @@ config FBSPLASH
             "NN" (ASCII decimal number) - percentage to show on progress bar
             "exit" - well you guessed it
 
+config IONICE
+        bool "ionice"
+        default n
+        help
+          Set/set program io scheduling class and priority
+          Requires kernel >= 2.6.13
+
 config INOTIFYD
         bool "inotifyd"
         default n
diff --git a/miscutils/Kbuild b/miscutils/Kbuild
index e6e434755..7665130e5 100644
--- a/miscutils/Kbuild
+++ b/miscutils/Kbuild
@@ -16,6 +16,7 @@ lib-$(CONFIG_DEVFSD)      += devfsd.o
 lib-$(CONFIG_DEVMEM)      += devmem.o
 lib-$(CONFIG_EJECT)       += eject.o
 lib-$(CONFIG_FBSPLASH)    += fbsplash.o
+lib-$(CONFIG_IONICE)      += ionice.o
 lib-$(CONFIG_HDPARM)      += hdparm.o
 lib-$(CONFIG_INOTIFYD)    += inotifyd.o
 lib-$(CONFIG_FEATURE_LAST_SMALL)+= last.o
diff --git a/miscutils/ionice.c b/miscutils/ionice.c
new file mode 100644
index 000000000..88d771c30
--- /dev/null
+++ b/miscutils/ionice.c
@@ -0,0 +1,99 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * ionice implementation for busybox based on linux-utils-ng 2.14
+ *
+ * Copyright (C) 2008 by  <u173034@informatik.uni-oldenburg.de>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include <sys/syscall.h>
+#include <asm/unistd.h>
+#include "libbb.h"
+
+static int ioprio_set(int which, int who, int ioprio)
+{
+        return syscall(SYS_ioprio_set, which, who, ioprio);
+}
+
+static int ioprio_get(int which, int who)
+{
+        return syscall(SYS_ioprio_get, which, who);
+}
+
+enum {
+        IOPRIO_WHO_PROCESS = 1,
+        IOPRIO_WHO_PGRP,
+        IOPRIO_WHO_USER
+};
+
+enum {
+        IOPRIO_CLASS_NONE,
+        IOPRIO_CLASS_RT,
+        IOPRIO_CLASS_BE,
+        IOPRIO_CLASS_IDLE
+};
+
+static const char to_prio[] = "none\0realtime\0best-effort\0idle";
+
+#define IOPRIO_CLASS_SHIFT      13
+
+int ionice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int ionice_main(int argc UNUSED_PARAM, char **argv)
+{
+        /* Defaults */
+        int ioclass = 0;
+        int pri = 0;
+        int pid = 0; /* affect own porcess */
+        int opt;
+        enum {
+                OPT_n = 1,
+                OPT_c = 2,
+                OPT_p = 4,
+        };
+
+        /* Numeric params */
+        opt_complementary = "n+:c+:p+";
+        /* '+': stop at first non-option */
+        opt = getopt32(argv, "+n:c:p:", &pri, &ioclass, &pid);
+        argv += optind;
+        
+        if (opt & OPT_c) {
+                if (ioclass > 3)
+                        bb_error_msg_and_die("bad class %d", ioclass);
+// Do we need this (compat?)?
+//              if (ioclass == IOPRIO_CLASS_NONE)
+//                      ioclass = IOPRIO_CLASS_BE;
+//              if (ioclass == IOPRIO_CLASS_IDLE) {
+//                      //if (opt & OPT_n)
+//                      //      bb_error_msg("ignoring priority for idle class");
+//                      pri = 7;
+//              }
+        }
+        
+        if (!(opt & (OPT_n|OPT_c))) {
+                if (!(opt & OPT_p) && *argv)
+                        pid = xatoi_u(*argv);
+
+                pri = ioprio_get(IOPRIO_WHO_PROCESS, pid);
+                if (pri == -1)
+                        bb_perror_msg_and_die("ioprio_%cet", 'g');
+
+                ioclass = (pri >> IOPRIO_CLASS_SHIFT) & 0x3;
+                pri &= 0xff;
+                printf((ioclass == IOPRIO_CLASS_IDLE) ? "%s\n" : "%s: prio %d\n",
+                                nth_string(to_prio, ioclass), pri);
+        } else {
+//printf("pri=%d class=%d val=%x\n",
+//pri, ioclass, pri | (ioclass << IOPRIO_CLASS_SHIFT));
+                pri |= (ioclass << IOPRIO_CLASS_SHIFT);
+                if (ioprio_set(IOPRIO_WHO_PROCESS, pid, pri) == -1)
+                        bb_perror_msg_and_die("ioprio_%cet", 's');
+                if (*argv) {
+                        BB_EXECVP(*argv, argv);
+                        bb_simple_perror_msg_and_die(*argv);
+                }
+        }
+
+        return EXIT_SUCCESS;
+}