busybox/util-linux/swaponoff.c
Tito Ragusa 8c7fcbd752 swapon: support "pri=NNN" in fstab
function                                             old     new   delta
swap_on_off_main                                     244     365    +121

Signed-off-by: Tito Ragusa <farmatito@tiscali.it>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2013-08-08 10:21:27 +02:00

158 lines
3.4 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini swapon/swapoff implementation for busybox
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
//usage:#define swapon_trivial_usage
//usage: "[-a]" 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_PRI(
//usage: "\n -p PRI Set swap device priority"
//usage: )
//usage:
//usage:#define swapoff_trivial_usage
//usage: "[-a] [DEVICE]"
//usage:#define swapoff_full_usage "\n\n"
//usage: "Stop swapping on DEVICE\n"
//usage: "\n -a Stop swapping on all swap devices"
#include "libbb.h"
#include <mntent.h>
#ifndef __BIONIC__
# include <sys/swap.h>
#endif
#if ENABLE_FEATURE_MOUNT_LABEL
# include "volume_id.h"
#else
# define resolve_mount_spec(fsname) ((void)0)
#endif
#ifndef MNTTYPE_SWAP
# define MNTTYPE_SWAP "swap"
#endif
#if ENABLE_FEATURE_SWAPON_PRI
struct globals {
int flags;
} FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1)
#define g_flags (G.flags)
#else
#define g_flags 0
#endif
#define INIT_G() do { } while (0)
static int swap_enable_disable(char *device)
{
int status;
struct stat st;
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) {
bb_simple_perror_msg(device);
return 1;
}
return 0;
}
static int do_em_all(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;
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
) {
#if ENABLE_FEATURE_SWAPON_PRI
char *p;
g_flags = 0; /* each swap space might have different flags */
p = strstr(m->mnt_opts, "pri=");
if (p) {
/* Max allowed 32767 (==SWAP_FLAG_PRIO_MASK) */
int swap_prio = MIN(bb_strtoull(p + 4 , NULL, 10), SWAP_FLAG_PRIO_MASK);
/* We want to allow "NNNN,foo", thus errno == EINVAL is allowed too */
if (errno != ERANGE) {
g_flags = SWAP_FLAG_PREFER |
(swap_prio << SWAP_FLAG_PRIO_SHIFT);
}
}
#endif
err += swap_enable_disable(m->mnt_fsname);
}
}
}
if (ENABLE_FEATURE_CLEAN_UP)
endmntent(f);
return err;
}
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;
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();
argv += optind;
if (!*argv)
bb_show_usage();
/* ret = 0; redundant */
do {
ret += swap_enable_disable(*argv);
} while (*++argv);
return ret;
}