Changeset 3621 in MondoRescue for branches/3.3/mindi-busybox/util-linux/swaponoff.c

Timestamp:

Dec 20, 2016, 4:07:32 PM (7 years ago)

Author:

Bruno Cornec

Message:

New 3?3 banch for incorporation of latest busybox 1.25. Changing minor version to handle potential incompatibilities.

Location:

branches/3.3

Files:

• . (copied) (copied from branches/3.2 )
• mindi-busybox/util-linux/swaponoff.c (modified) (4 diffs)

branches/3.3/mindi-busybox/util-linux/swaponoff.c

@@ -9 +9 @@
 
 //usage:#define swapon_trivial_usage
-//usage:       "[-a]" IF_FEATURE_SWAPON_PRI(" [-p PRI]") " [DEVICE]"
+//usage:       "[-a] [-e]" IF_FEATURE_SWAPON_DISCARD(" [-d[POL]]") IF_FEATURE_SWAPON_PRI(" [-p PRI]") " [DEVICE]"
 //usage:#define swapon_full_usage "\n\n"
 //usage:       "Start swapping on DEVICE\n"
 //usage:     "\n    -a  Start swapping on all swap devices"
+//usage:    IF_FEATURE_SWAPON_DISCARD(
+//usage:     "\n    -d[POL] Discard blocks at swapon (POL=once),"
+//usage:     "\n        as freed (POL=pages), or both (POL omitted)"
+//usage:    )
+//usage:     "\n    -e  Silently skip devices that do not exist"
 //usage:    IF_FEATURE_SWAPON_PRI(
 //usage:     "\n    -p PRI  Set swap device priority"
@@ -24 +29 @@
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <mntent.h>
 #ifndef __BIONIC__
@@ -39 +45 @@
 #endif
 
-#if ENABLE_FEATURE_SWAPON_PRI
+#if ENABLE_FEATURE_SWAPON_DISCARD
+#ifndef SWAP_FLAG_DISCARD
+#define SWAP_FLAG_DISCARD 0x10000
+#endif
+#ifndef SWAP_FLAG_DISCARD_ONCE
+#define SWAP_FLAG_DISCARD_ONCE 0x20000
+#endif
+#ifndef SWAP_FLAG_DISCARD_PAGES
+#define SWAP_FLAG_DISCARD_PAGES 0x40000
+#endif
+#define SWAP_FLAG_DISCARD_MASK \
+    (SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | SWAP_FLAG_DISCARD_PAGES)
+#endif
+
+
+#if ENABLE_FEATURE_SWAPON_DISCARD || ENABLE_FEATURE_SWAPON_PRI
 struct globals {
     int flags;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define g_flags (G.flags)
+#define save_g_flags()    int save_g_flags = g_flags
+#define restore_g_flags() g_flags = save_g_flags
 #else
 #define g_flags 0
-#endif
-#define INIT_G() do { } while (0)
+#define save_g_flags()    ((void)0)
+#define restore_g_flags() ((void)0)
+#endif
+#define INIT_G() do { setup_common_bufsiz(); } while (0)
+
+#define do_swapoff   (applet_name[5] == 'f')
+
+/* Command line options */
+enum {
+    OPTBIT_a,                              /* -a all      */
+    OPTBIT_e,                              /* -e ifexists */
+    IF_FEATURE_SWAPON_DISCARD( OPTBIT_d ,) /* -d discard  */
+    IF_FEATURE_SWAPON_PRI    ( OPTBIT_p ,) /* -p priority */
+    OPT_a = 1 << OPTBIT_a,
+    OPT_e = 1 << OPTBIT_e,
+    OPT_d = IF_FEATURE_SWAPON_DISCARD((1 << OPTBIT_d)) + 0,
+    OPT_p = IF_FEATURE_SWAPON_PRI    ((1 << OPTBIT_p)) + 0,
+};
+
+#define OPT_ALL      (option_mask32 & OPT_a)
+#define OPT_DISCARD  (option_mask32 & OPT_d)
+#define OPT_IFEXISTS (option_mask32 & OPT_e)
+#define OPT_PRIO     (option_mask32 & OPT_p)
 
 static int swap_enable_disable(char *device)
 {
-    int status;
-    struct stat st;
+    int err = 0;
+    int quiet = 0;
 
     resolve_mount_spec(&device);
-    xstat(device, &st);
-
-#if ENABLE_DESKTOP
-    /* test for holes */
-    if (S_ISREG(st.st_mode))
-        if (st.st_blocks * (off_t)512 < st.st_size)
-            bb_error_msg("warning: swap file has holes");
-#endif
-
-    if (applet_name[5] == 'n')
-        status = swapon(device, g_flags);
-    else
-        status = swapoff(device);
-
-    if (status != 0) {
+
+    if (do_swapoff) {
+        err = swapoff(device);
+        /* Don't complain on OPT_ALL if not a swap device or if it doesn't exist */
+        quiet = (OPT_ALL && (errno == EINVAL || errno == ENOENT));
+    } else {
+        /* swapon */
+        struct stat st;
+        err = stat(device, &st);
+        if (!err) {
+            if (ENABLE_DESKTOP && S_ISREG(st.st_mode)) {
+                if (st.st_blocks * (off_t)512 < st.st_size) {
+                    bb_error_msg("%s: file has holes", device);
+                    return 1;
+                }
+            }
+            err = swapon(device, g_flags);
+            /* Don't complain on swapon -a if device is already in use */
+            quiet = (OPT_ALL && errno == EBUSY);
+        }
+        /* Don't complain if file does not exist with -e option */
+        if (err && OPT_IFEXISTS && errno == ENOENT)
+            err = 0;
+    }
+
+    if (err && !quiet) {
         bb_simple_perror_msg(device);
         return 1;
     }
-
     return 0;
 }
 
-static int do_em_all(void)
+#if ENABLE_FEATURE_SWAPON_DISCARD
+static void set_discard_flag(char *s)
+{
+    /* Unset the flag first to allow fstab options to override */
+    /* options set on the command line */
+    g_flags = (g_flags & ~SWAP_FLAG_DISCARD_MASK) | SWAP_FLAG_DISCARD;
+
+    if (!s) /* No optional policy value on the commandline */
+        return;
+    /* Skip prepended '=' */
+    if (*s == '=')
+        s++;
+    /* For fstab parsing: remove other appended options */
+    *strchrnul(s, ',') = '\0';
+
+    if (strcmp(s, "once") == 0)
+        g_flags |= SWAP_FLAG_DISCARD_ONCE;
+    if  (strcmp(s, "pages") == 0)
+        g_flags |= SWAP_FLAG_DISCARD_PAGES;
+}
+#else
+#define set_discard_flag(s) ((void)0)
+#endif
+
+#if ENABLE_FEATURE_SWAPON_PRI
+static void set_priority_flag(char *s)
+{
+    unsigned prio;
+
+    /* For fstab parsing: remove other appended options */
+    *strchrnul(s, ',') = '\0';
+    /* Max allowed 32767 (== SWAP_FLAG_PRIO_MASK) */
+    prio = bb_strtou(s, NULL, 10);
+    if (!errno) {
+        /* Unset the flag first to allow fstab options to override */
+        /* options set on the command line */
+        g_flags = (g_flags & ~SWAP_FLAG_PRIO_MASK) | SWAP_FLAG_PREFER |
+                    MIN(prio, SWAP_FLAG_PRIO_MASK);
+    }
+}
+#else
+#define set_priority_flag(s) ((void)0)
+#endif
+
+static int do_em_all_in_fstab(void)
 {
     struct mntent *m;
-    FILE *f;
-    int err;
-
-    f = setmntent("/etc/fstab", "r");
-    if (f == NULL)
-        bb_perror_msg_and_die("/etc/fstab");
-
-    err = 0;
+    int err = 0;
+    FILE *f = xfopen_for_read("/etc/fstab");
+
     while ((m = getmntent(f)) != NULL) {
         if (strcmp(m->mnt_type, MNTTYPE_SWAP) == 0) {
             /* swapon -a should ignore entries with noauto,
-             * but swapoff -a should process them */
-            if (applet_name[5] != 'n'
-             || hasmntopt(m, MNTOPT_NOAUTO) == NULL
-            ) {
-                err += swap_enable_disable(m->mnt_fsname);
+             * but swapoff -a should process them
+             */
+            if (do_swapoff || hasmntopt(m, MNTOPT_NOAUTO) == NULL) {
+                /* each swap space might have different flags */
+                /* save global flags for the next round */
+                save_g_flags();
+                if (ENABLE_FEATURE_SWAPON_DISCARD) {
+                    char *p = hasmntopt(m, "discard");
+                    if (p) {
+                        /* move to '=' or to end of string */
+                        p += 7;
+                        set_discard_flag(p);
+                    }
+                }
+                if (ENABLE_FEATURE_SWAPON_PRI) {
+                    char *p = hasmntopt(m, "pri");
+                    if (p) {
+                        set_priority_flag(p + 4);
+                    }
+                }
+                err |= swap_enable_disable(m->mnt_fsname);
+                restore_g_flags();
             }
         }
@@ -107 +217 @@
 }
 
+static int do_all_in_proc_swaps(void)
+{
+    char *line;
+    int err = 0;
+    FILE *f = fopen_for_read("/proc/swaps");
+    /* Don't complain if missing */
+    if (f) {
+        while ((line = xmalloc_fgetline(f)) != NULL) {
+            if (line[0] == '/') {
+                *strchrnul(line, ' ') = '\0';
+                err |= swap_enable_disable(line);
+            }
+            free(line);
+        }
+        if (ENABLE_FEATURE_CLEAN_UP)
+            fclose(f);
+    }
+
+    return err;
+}
+
+#define OPTSTR_SWAPON "ae" \
+    IF_FEATURE_SWAPON_DISCARD("d::") \
+    IF_FEATURE_SWAPON_PRI("p:")
+
 int swap_on_off_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int swap_on_off_main(int argc UNUSED_PARAM, char **argv)
 {
-    int ret;
+    IF_FEATURE_SWAPON_PRI(char *prio;)
+    IF_FEATURE_SWAPON_DISCARD(char *discard = NULL;)
+    int ret = 0;
 
     INIT_G();
 
-#if !ENABLE_FEATURE_SWAPON_PRI
-    ret = getopt32(argv, "a");
-#else
-    if (applet_name[5] == 'n')
-        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();
+    getopt32(argv, do_swapoff ? "ae" : OPTSTR_SWAPON
+            IF_FEATURE_SWAPON_DISCARD(, &discard)
+            IF_FEATURE_SWAPON_PRI(, &prio)
+    );
 
     argv += optind;
-    if (!*argv)
+
+    if (OPT_DISCARD) {
+        set_discard_flag(discard);
+    }
+    if (OPT_PRIO) {
+        set_priority_flag(prio);
+    }
+
+    if (OPT_ALL) {
+        /* swapoff -a does also /proc/swaps */
+        if (do_swapoff)
+            ret = do_all_in_proc_swaps();
+        ret |= do_em_all_in_fstab();
+    } else if (!*argv) {
+        /* if not -a we need at least one arg */
         bb_show_usage();
-
-    /* ret = 0; redundant */
-    do {
-        ret += swap_enable_disable(*argv);
-    } while (*++argv);
-
+    }
+    /* Unset -a now to allow for more messages in swap_enable_disable */
+    option_mask32 = option_mask32 & ~OPT_a;
+    /* Now process devices on the commandline if any */
+    while (*argv) {
+        ret |= swap_enable_disable(*argv++);
+    }
     return ret;
 }