swapon: optional -p PRIO support (by Francois Barel <frabar666 AT gmail.com>)

function                                             old     new   delta
swap_on_off_main                                     153     216     +63
packed_usage                                       24190   24214     +24
swap_enable_disable                                  127     131      +4
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 91/0)               Total: 91 bytes

diff --git a/include/usage.h b/include/usage.h
index 56198cfa516722d4aa51d6c938d66306cf85da3a..d5c53a25568e797aaf4690abe36d5c2b70a3220d 100644 (file)
--- a/include/usage.h
+++ b/include/usage.h
@@ -3809,11 +3809,14 @@
      "\n       -a      Stop swapping on all swap devices" \
 
 #define swapon_trivial_usage \
-       "[-a] [DEVICE]"
+       "[-a]" USE_FEATURE_SWAPON_PRI(" [-p pri]") " [DEVICE]"
 #define swapon_full_usage "\n\n" \
        "Start swapping on DEVICE\n" \
      "\nOptions:" \
      "\n       -a      Start swapping on all swap devices" \
+       USE_FEATURE_SWAPON_PRI( \
+     "\n       -p pri  Set swap device priority" \
+       ) \
 
 #define switch_root_trivial_usage \
        "[-c /dev/console] NEW_ROOT NEW_INIT [ARGUMENTS_TO_INIT]"

diff --git a/util-linux/Config.in b/util-linux/Config.in
index c30091a7a59c380ceeaad6c3093713bde48721c6..3b7630e6be832952d3faedd63339e27ec32481d4 100644 (file)
--- a/util-linux/Config.in
+++ b/util-linux/Config.in
@@ -743,6 +743,13 @@ config SWAPONOFF
          space.  If you are not using any swap space, you can leave this
          option disabled.
 
+config FEATURE_SWAPON_PRI
+       bool "Support option -p in swapon"
+       default n
+       depends on SWAPONOFF
+       help
+         Enable support for setting swap device priority in swapon.
+
 config SWITCH_ROOT
        bool "switch_root"
        default n

diff --git a/util-linux/swaponoff.c b/util-linux/swaponoff.c
index beefac030441cf766aa81a5ae9e899a0aac388a3..6eafa3e2116e638e6ad9c79dc02b3141dddd1635 100644 (file)
--- a/util-linux/swaponoff.c
+++ b/util-linux/swaponoff.c
@@ -11,6 +11,16 @@
 #include <mntent.h>
 #include <sys/swap.h>
 
+#if ENABLE_FEATURE_SWAPON_PRI
+struct globals {
+       int flags;
+};
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define g_flags (G.flags)
+#else
+#define g_flags 0
+#endif
+
 static int swap_enable_disable(char *device)
 {
        int status;
@@ -26,7 +36,7 @@ static int swap_enable_disable(char *device)
 #endif
 
        if (applet_name[5] == 'n')
-               status = swapon(device, 0);
+               status = swapon(device, g_flags);
        else
                status = swapoff(device);
 
@@ -63,15 +73,30 @@ int swap_on_off_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
        int ret;
 
-       if (!argv[1])
-               bb_show_usage();
-
+#if !ENABLE_FEATURE_SWAPON_PRI
        ret = getopt32(argv, "a");
-       if (ret)
+#else
+       opt_complementary = "p+";
+       ret = getopt32(argv, (applet_name[5] == 'n') ? "ap:" : "a", &g_flags);
+
+       if (ret & 2) { // -p
+               g_flags = SWAP_FLAG_PREFER |
+                       ((g_flags & SWAP_FLAG_PRIO_MASK) << SWAP_FLAG_PRIO_SHIFT);
+               ret &= 1;
+       }
+#endif
+
+       if (ret /* & 1: not needed */) // -a
                return do_em_all();
 
+       argv += optind;
+       if (!*argv)
+               bb_show_usage();
+
        /* ret = 0; redundant */
-       while (*++argv)
+       do {
                ret += swap_enable_disable(*argv);
+       } while (*++argv);
+
        return ret;
 }