Merge branch 'busybox' into merge

Conflicts:
	coreutils/od_bloaty.c
	libbb/lineedit.c

14 files changed, 152 insertions, 132 deletions

diff --git a/util-linux/Config.src b/util-linux/Config.src
index c1cd6daa4..854b3682e 100644
--- a/util-linux/Config.src
+++ b/util-linux/Config.src
@@ -434,94 +434,6 @@ config MORE
           you will probably find this utility very helpful. If you don't have
           any need to reading text files, you can leave this disabled.
 
-config MOUNT
-        bool "mount"
-        default y
-        select PLATFORM_LINUX
-        help
-          All files and filesystems in Unix are arranged into one big directory
-          tree. The 'mount' utility is used to graft a filesystem onto a
-          particular part of the tree. A filesystem can either live on a block
-          device, or it can be accessible over the network, as is the case with
-          NFS filesystems. Most people using BusyBox will also want to enable
-          the 'mount' utility.
-
-config FEATURE_MOUNT_FAKE
-        bool "Support option -f"
-        default y
-        depends on MOUNT
-        help
-          Enable support for faking a file system mount.
-
-config FEATURE_MOUNT_VERBOSE
-        bool "Support option -v"
-        default y
-        depends on MOUNT
-        help
-          Enable multi-level -v[vv...] verbose messages. Useful if you
-          debug mount problems and want to see what is exactly passed
-          to the kernel.
-
-config FEATURE_MOUNT_HELPERS
-        bool "Support mount helpers"
-        default n
-        depends on MOUNT
-        help
-          Enable mounting of virtual file systems via external helpers.
-          E.g. "mount obexfs#-b00.11.22.33.44.55 /mnt" will in effect call
-          "obexfs -b00.11.22.33.44.55 /mnt"
-          Also "mount -t sometype [-o opts] fs /mnt" will try
-          "sometype [-o opts] fs /mnt" if simple mount syscall fails.
-          The idea is to use such virtual filesystems in /etc/fstab.
-
-config FEATURE_MOUNT_LABEL
-        bool "Support specifying devices by label or UUID"
-        default y
-        depends on MOUNT
-        select VOLUMEID
-        help
-          This allows for specifying a device by label or uuid, rather than by
-          name. This feature utilizes the same functionality as blkid/findfs.
-          This also enables label or uuid support for swapon.
-
-config FEATURE_MOUNT_NFS
-        bool "Support mounting NFS file systems on Linux < 2.6.23"
-        default n
-        depends on MOUNT
-        select FEATURE_HAVE_RPC
-        select FEATURE_SYSLOG
-        help
-          Enable mounting of NFS file systems on Linux kernels prior
-          to version 2.6.23. Note that in this case mounting of NFS
-          over IPv6 will not be possible.
-
-          Note that this option links in RPC support from libc,
-          which is rather large (~10 kbytes on uclibc).
-
-config FEATURE_MOUNT_CIFS
-        bool "Support mounting CIFS/SMB file systems"
-        default y
-        depends on MOUNT
-        help
-          Enable support for samba mounts.
-
-config FEATURE_MOUNT_FLAGS
-        depends on MOUNT
-        bool "Support lots of -o flags in mount"
-        default y
-        help
-          Without this, mount only supports ro/rw/remount. With this, it
-          supports nosuid, suid, dev, nodev, exec, noexec, sync, async, atime,
-          noatime, diratime, nodiratime, loud, bind, move, shared, slave,
-          private, unbindable, rshared, rslave, rprivate, and runbindable.
-
-config FEATURE_MOUNT_FSTAB
-        depends on MOUNT
-        bool "Support /etc/fstab and -a"
-        default y
-        help
-          Support mount all and looking for files in /etc/fstab.
-
 config PIVOT_ROOT
         bool "pivot_root"
         default y
diff --git a/util-linux/acpid.c b/util-linux/acpid.c
index 38421c2d7..0f2cb6bdc 100644
--- a/util-linux/acpid.c
+++ b/util-linux/acpid.c
@@ -121,10 +121,8 @@ static void process_event(const char *event)
         char *handler = xasprintf("./%s", event);
         const char *args[] = { "run-parts", handler, NULL };
 
-        // debug info
-        if (option_mask32 & OPT_d) {
-                bb_error_msg("%s", event);
-        }
+        // log the event
+        bb_error_msg("%s", event);
 
         // spawn handler
         // N.B. run-parts would require scripts to have #!/bin/sh
@@ -153,7 +151,7 @@ static const char *find_action(struct input_event *ev, const char *buf)
                 }
 
                 if (buf) {
-                        if (strncmp(buf, evt_tab[i].desc, strlen(buf)) == 0) {
+                        if (is_prefixed_with(evt_tab[i].desc, buf)) {
                                 action = evt_tab[i].desc;
                                 break;
                         }
@@ -256,7 +254,7 @@ int acpid_main(int argc UNUSED_PARAM, char **argv)
                 /* No -d "Debug", we log to log file.
                  * This includes any output from children.
                  */
-                xmove_fd(xopen(opt_logfile, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
+                xmove_fd(xopen(opt_logfile, O_WRONLY | O_CREAT | O_APPEND), STDOUT_FILENO);
                 xdup2(STDOUT_FILENO, STDERR_FILENO);
                 /* Also, acpid's messages (but not children) will go to syslog too */
                 openlog(applet_name, LOG_PID, LOG_DAEMON);
diff --git a/util-linux/fdisk.c b/util-linux/fdisk.c
index 39eb27b47..7fe70fb72 100644
--- a/util-linux/fdisk.c
+++ b/util-linux/fdisk.c
@@ -2781,14 +2781,14 @@ is_ide_cdrom_or_tape(const char *device)
            the process hangs on the attempt to read a music CD.
            So try to be careful. This only works since 2.1.73. */
 
-        if (strncmp("/dev/hd", device, 7))
+        if (!is_prefixed_with(device, "/dev/hd"))
                 return 0;
 
         snprintf(buf, sizeof(buf), "/proc/ide/%s/media", device+5);
         procf = fopen_for_read(buf);
         if (procf != NULL && fgets(buf, sizeof(buf), procf))
-                is_ide = (!strncmp(buf, "cdrom", 5) ||
-                          !strncmp(buf, "tape", 4));
+                is_ide = (is_prefixed_with(buf, "cdrom") ||
+                          is_prefixed_with(buf, "tape"));
         else
                 /* Now when this proc file does not exist, skip the
                    device when it is read-only. */
diff --git a/util-linux/fdisk_osf.c b/util-linux/fdisk_osf.c
index ff16389bd..af04cfcc8 100644
--- a/util-linux/fdisk_osf.c
+++ b/util-linux/fdisk_osf.c
@@ -854,7 +854,7 @@ xbsd_initlabel(struct partition *p)
 
         d->d_magic = BSD_DISKMAGIC;
 
-        if (strncmp(disk_device, "/dev/sd", 7) == 0)
+        if (is_prefixed_with(disk_device, "/dev/sd"))
                 d->d_type = BSD_DTYPE_SCSI;
         else
                 d->d_type = BSD_DTYPE_ST506;
diff --git a/util-linux/fdisk_sgi.c b/util-linux/fdisk_sgi.c
index 785fc661b..23ebc56ef 100644
--- a/util-linux/fdisk_sgi.c
+++ b/util-linux/fdisk_sgi.c
@@ -440,7 +440,7 @@ sgi_write_table(void)
                 (unsigned int*)sgilabel, sizeof(*sgilabel)) == 0);
 
         write_sector(0, sgilabel);
-        if (!strncmp((char*)sgilabel->directory[0].vol_file_name, "sgilabel", 8)) {
+        if (is_prefixed_with((char*)sgilabel->directory[0].vol_file_name, "sgilabel")) {
                 /*
                  * keep this habit of first writing the "sgilabel".
                  * I never tested whether it works without (AN 981002).
diff --git a/util-linux/findfs.c b/util-linux/findfs.c
index 49e8979ac..07734f359 100644
--- a/util-linux/findfs.c
+++ b/util-linux/findfs.c
@@ -27,7 +27,7 @@ int findfs_main(int argc UNUSED_PARAM, char **argv)
         if (!dev)
                 bb_show_usage();
 
-        if (strncmp(dev, "/dev/", 5) == 0) {
+        if (is_prefixed_with(dev, "/dev/")) {
                 /* Just pass any /dev/xxx name right through.
                  * This might aid in some scripts being able
                  * to call this unconditionally */
diff --git a/util-linux/fstrim.c b/util-linux/fstrim.c
index 675a02184..51400ef0b 100644
--- a/util-linux/fstrim.c
+++ b/util-linux/fstrim.c
@@ -32,7 +32,7 @@
 //usage:       "        -o OFFSET       Offset in bytes to discard from"
 //usage:     "\n        -l LEN          Bytes to discard"
 //usage:     "\n        -m MIN          Minimum extent length"
-//usage:     "\n        -v,             Print number of discarded bytes"
+//usage:     "\n        -v              Print number of discarded bytes"
 //usage:        )
 
 #include "libbb.h"
diff --git a/util-linux/hwclock.c b/util-linux/hwclock.c
index 3f531555b..6c99977cf 100644
--- a/util-linux/hwclock.c
+++ b/util-linux/hwclock.c
@@ -69,7 +69,7 @@ static void show_clock(const char **pp_rtcname, int utc)
         strftime(cp, sizeof(cp), "%c", ptm);
 #else
         char *cp = ctime(&t);
-        strchrnul(cp, '\n')[0] = '\0';
+        chomp(cp);
 #endif
 
 #if !SHOW_HWCLOCK_DIFF
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index b2d56575f..ccc00d365 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -610,7 +610,7 @@ static void make_device(char *device_name, char *path, int operation)
          * We use strstr("/block/") to forestall future surprises.
          */
         type = S_IFCHR;
-        if (strstr(path, "/block/") || (G.subsystem && strncmp(G.subsystem, "block", 5) == 0))
+        if (strstr(path, "/block/") || (G.subsystem && is_prefixed_with(G.subsystem, "block")))
                 type = S_IFBLK;
 
 #if ENABLE_FEATURE_MDEV_CONF
diff --git a/util-linux/mount.c b/util-linux/mount.c
index 62fd41fd7..cb40c802d 100644
--- a/util-linux/mount.c
+++ b/util-linux/mount.c
@@ -17,8 +17,103 @@
 // mount_it_now() does the actual mount.
 //
 
+//config:config MOUNT
+//config:       bool "mount"
+//config:       default y
+//config:       select PLATFORM_LINUX
+//config:       help
+//config:         All files and filesystems in Unix are arranged into one big directory
+//config:         tree. The 'mount' utility is used to graft a filesystem onto a
+//config:         particular part of the tree. A filesystem can either live on a block
+//config:         device, or it can be accessible over the network, as is the case with
+//config:         NFS filesystems. Most people using BusyBox will also want to enable
+//config:         the 'mount' utility.
+//config:
+//config:config FEATURE_MOUNT_FAKE
+//config:       bool "Support option -f"
+//config:       default y
+//config:       depends on MOUNT
+//config:       help
+//config:         Enable support for faking a file system mount.
+//config:
+//config:config FEATURE_MOUNT_VERBOSE
+//config:       bool "Support option -v"
+//config:       default y
+//config:       depends on MOUNT
+//config:       help
+//config:         Enable multi-level -v[vv...] verbose messages. Useful if you
+//config:         debug mount problems and want to see what is exactly passed
+//config:         to the kernel.
+//config:
+//config:config FEATURE_MOUNT_HELPERS
+//config:       bool "Support mount helpers"
+//config:       default n
+//config:       depends on MOUNT
+//config:       help
+//config:         Enable mounting of virtual file systems via external helpers.
+//config:         E.g. "mount obexfs#-b00.11.22.33.44.55 /mnt" will in effect call
+//config:         "obexfs -b00.11.22.33.44.55 /mnt"
+//config:         Also "mount -t sometype [-o opts] fs /mnt" will try
+//config:         "sometype [-o opts] fs /mnt" if simple mount syscall fails.
+//config:         The idea is to use such virtual filesystems in /etc/fstab.
+//config:
+//config:config FEATURE_MOUNT_LABEL
+//config:       bool "Support specifying devices by label or UUID"
+//config:       default y
+//config:       depends on MOUNT
+//config:       select VOLUMEID
+//config:       help
+//config:         This allows for specifying a device by label or uuid, rather than by
+//config:         name. This feature utilizes the same functionality as blkid/findfs.
+//config:         This also enables label or uuid support for swapon.
+//config:
+//config:config FEATURE_MOUNT_NFS
+//config:       bool "Support mounting NFS file systems on Linux < 2.6.23"
+//config:       default n
+//config:       depends on MOUNT
+//config:       select FEATURE_HAVE_RPC
+//config:       select FEATURE_SYSLOG
+//config:       help
+//config:         Enable mounting of NFS file systems on Linux kernels prior
+//config:         to version 2.6.23. Note that in this case mounting of NFS
+//config:         over IPv6 will not be possible.
+//config:
+//config:         Note that this option links in RPC support from libc,
+//config:         which is rather large (~10 kbytes on uclibc).
+//config:
+//config:config FEATURE_MOUNT_CIFS
+//config:       bool "Support mounting CIFS/SMB file systems"
+//config:       default y
+//config:       depends on MOUNT
+//config:       help
+//config:         Enable support for samba mounts.
+//config:
+//config:config FEATURE_MOUNT_FLAGS
+//config:       depends on MOUNT
+//config:       bool "Support lots of -o flags in mount"
+//config:       default y
+//config:       help
+//config:         Without this, mount only supports ro/rw/remount. With this, it
+//config:         supports nosuid, suid, dev, nodev, exec, noexec, sync, async, atime,
+//config:         noatime, diratime, nodiratime, loud, bind, move, shared, slave,
+//config:         private, unbindable, rshared, rslave, rprivate, and runbindable.
+//config:
+//config:config FEATURE_MOUNT_FSTAB
+//config:       depends on MOUNT
+//config:       bool "Support /etc/fstab and -a"
+//config:       default y
+//config:       help
+//config:         Support mount all and looking for files in /etc/fstab.
+//config:
+//config:config FEATURE_MOUNT_OTHERTAB
+//config:       depends on FEATURE_MOUNT_FSTAB
+//config:       bool "Support -T <alt_fstab>"
+//config:       default y
+//config:       help
+//config:         Support mount -T (specifying an alternate fstab)
+
 //usage:#define mount_trivial_usage
-//usage:       "[OPTIONS] [-o OPTS] DEVICE NODE"
+//usage:       "[OPTIONS] [-o OPT] DEVICE NODE"
 //usage:#define mount_full_usage "\n\n"
 //usage:       "Mount a filesystem. Filesystem autodetection requires /proc.\n"
 //usage:     "\n        -a              Mount all filesystems in fstab"
@@ -41,8 +136,11 @@
 //usage:        )
 ////usage:   "\n        -s              Sloppy (ignored)"
 //usage:     "\n        -r              Read-only mount"
-//usage:     "\n        -w              Read-write mount (default)"
+////usage:     "\n      -w              Read-write mount (default)"
 //usage:     "\n        -t FSTYPE[,...] Filesystem type(s)"
+//usage:        IF_FEATURE_MOUNT_OTHERTAB(
+//usage:     "\n        -T FILE         Read FILE instead of /etc/fstab"
+//usage:        )
 //usage:     "\n        -O OPT          Mount only filesystems with option OPT (-a only)"
 //usage:     "\n-o OPT:"
 //usage:        IF_FEATURE_MOUNT_LOOP(
@@ -64,7 +162,7 @@
 //usage:     "\n        move            Relocate an existing mount point"
 //usage:        )
 //usage:     "\n        remount         Remount a mounted filesystem, changing flags"
-//usage:     "\n        ro/rw           Same as -r/-w"
+//usage:     "\n        ro              Same as -r"
 //usage:     "\n"
 //usage:     "\nThere are filesystem-specific -o flags."
 //usage:
@@ -167,7 +265,7 @@ enum {
 };
 
 
-#define OPTION_STR "o:t:rwanfvsiO:"
+#define OPTION_STR "o:t:rwanfvsiO:" IF_FEATURE_MOUNT_OTHERTAB("T:")
 enum {
         OPT_o = (1 << 0),
         OPT_t = (1 << 1),
@@ -180,6 +278,7 @@ enum {
         OPT_s = (1 << 8),
         OPT_i = (1 << 9),
         OPT_O = (1 << 10),
+        OPT_T = (1 << 11),
 };
 
 #if ENABLE_FEATURE_MTAB_SUPPORT
@@ -542,7 +641,7 @@ static llist_t *get_block_backed_filesystems(void)
                 if (!f) continue;
 
                 while ((buf = xmalloc_fgetline(f)) != NULL) {
-                        if (strncmp(buf, "nodev", 5) == 0 && isspace(buf[5]))
+                        if (is_prefixed_with(buf, "nodev") && isspace(buf[5]))
                                 goto next;
                         fs = skip_whitespace(buf);
                         if (*fs == '#' || *fs == '*' || !*fs)
@@ -1265,9 +1364,9 @@ static NOINLINE int nfsmount(struct mntent *mp, unsigned long vfsflags, char *fi
                                                 strcspn(opteq, " \t\n\r,"));
                                 continue;
                         case 18: // "proto"
-                                if (!strncmp(opteq, "tcp", 3))
+                                if (is_prefixed_with(opteq, "tcp"))
                                         tcp = 1;
-                                else if (!strncmp(opteq, "udp", 3))
+                                else if (is_prefixed_with(opteq, "udp"))
                                         tcp = 0;
                                 else
                                         bb_error_msg("warning: unrecognized proto= option");
@@ -1360,7 +1459,7 @@ static NOINLINE int nfsmount(struct mntent *mp, unsigned long vfsflags, char *fi
                                 "rdirplus\0"
                                 "acl\0";
                         int val = 1;
-                        if (!strncmp(opt, "no", 2)) {
+                        if (is_prefixed_with(opt, "no")) {
                                 val = 0;
                                 opt += 2;
                         }
@@ -1880,7 +1979,7 @@ static int singlemount(struct mntent *mp, int ignore_busy)
         }
 
         // Might this be an NFS filesystem?
-        if ((!mp->mnt_type || strncmp(mp->mnt_type, "nfs", 3) == 0)
+        if ((!mp->mnt_type || is_prefixed_with(mp->mnt_type, "nfs"))
          && strchr(mp->mnt_fsname, ':') != NULL
         ) {
                 if (!mp->mnt_type)
@@ -2034,7 +2133,7 @@ int mount_main(int argc UNUSED_PARAM, char **argv)
         char *O_optmatch = NULL;
         char *storage_path;
         llist_t *lst_o = NULL;
-        const char *fstabname;
+        const char *fstabname = "/etc/fstab";
         FILE *fstab;
         int i, j;
         int rc = EXIT_SUCCESS;
@@ -2061,6 +2160,7 @@ int mount_main(int argc UNUSED_PARAM, char **argv)
         // Max 2 params; -o is a list, -v is a counter
         opt_complementary = "?2o::" IF_FEATURE_MOUNT_VERBOSE("vv");
         opt = getopt32(argv, OPTION_STR, &lst_o, &fstype, &O_optmatch
+                        IF_FEATURE_MOUNT_OTHERTAB(, &fstabname)
                         IF_FEATURE_MOUNT_VERBOSE(, &verbose));
         while (lst_o) append_mount_options(&cmdopts, llist_pop(&lst_o)); // -o
         if (opt & OPT_r) append_mount_options(&cmdopts, "ro"); // -r
@@ -2128,8 +2228,10 @@ int mount_main(int argc UNUSED_PARAM, char **argv)
                 return rc;
         }
 
+        // A malicious user could overmount /usr without this.
+        if (ENABLE_FEATURE_MOUNT_OTHERTAB && nonroot)
+                fstabname = "/etc/fstab";
         // Open either fstab or mtab
-        fstabname = "/etc/fstab";
         if (cmdopt_flags & MS_REMOUNT) {
                 // WARNING. I am not sure this matches util-linux's
                 // behavior. It's possible util-linux does not
diff --git a/util-linux/rdate.c b/util-linux/rdate.c
index 6e35cd519..8075ef6af 100644
--- a/util-linux/rdate.c
+++ b/util-linux/rdate.c
@@ -11,9 +11,9 @@
 //usage:#define rdate_trivial_usage
 //usage:       "[-sp] HOST"
 //usage:#define rdate_full_usage "\n\n"
-//usage:       "Get and possibly set the system date/time from a remote HOST\n"
-//usage:     "\n        -s      Set the system date/time (default)"
-//usage:     "\n        -p      Print the date/time"
+//usage:       "Get and possibly set system time from a remote HOST\n"
+//usage:     "\n        -s      Set system time (default)"
+//usage:     "\n        -p      Print time"
 
 #include "libbb.h"
 
@@ -36,7 +36,7 @@ static time_t askremotedate(const char *host)
         fd = create_and_connect_stream_or_die(host, bb_lookup_port("time", "tcp", 37));
 
         if (safe_read(fd, &nett, 4) != 4)    /* read time from server */
-                bb_error_msg_and_die("%s did not send the complete time", host);
+                bb_error_msg_and_die("%s: %s", host, "short read");
         if (ENABLE_FEATURE_CLEAN_UP)
                 close(fd);
 
diff --git a/util-linux/rtcwake.c b/util-linux/rtcwake.c
index 33cdbfad4..8aee0cfcb 100644
--- a/util-linux/rtcwake.c
+++ b/util-linux/rtcwake.c
@@ -32,18 +32,18 @@
 //usage:     "\n        -l,--local      Clock is set to local time"
 //usage:     "\n        -u,--utc        Clock is set to UTC time"
 //usage:     "\n        -d,--device=DEV Specify the RTC device"
-//usage:     "\n        -m,--mode=MODE  Set the sleep state (default: standby)"
-//usage:     "\n        -s,--seconds=SEC Set the timeout in SEC seconds from now"
-//usage:     "\n        -t,--time=TIME  Set the timeout to TIME seconds from epoch"
+//usage:     "\n        -m,--mode=MODE  Set sleep state (default: standby)"
+//usage:     "\n        -s,--seconds=SEC Set timeout in SEC seconds from now"
+//usage:     "\n        -t,--time=TIME  Set timeout to TIME seconds from epoch"
 //usage:        )
 //usage:        IF_NOT_LONG_OPTS(
 //usage:     "\n        -a      Read clock mode from adjtime"
 //usage:     "\n        -l      Clock is set to local time"
 //usage:     "\n        -u      Clock is set to UTC time"
 //usage:     "\n        -d DEV  Specify the RTC device"
-//usage:     "\n        -m MODE Set the sleep state (default: standby)"
-//usage:     "\n        -s SEC  Set the timeout in SEC seconds from now"
-//usage:     "\n        -t TIME Set the timeout to TIME seconds from epoch"
+//usage:     "\n        -m MODE Set sleep state (default: standby)"
+//usage:     "\n        -s SEC  Set timeout in SEC seconds from now"
+//usage:     "\n        -t TIME Set timeout to TIME seconds from epoch"
 //usage:        )
 
 #include "libbb.h"
@@ -66,7 +66,7 @@ static NOINLINE bool may_wakeup(const char *rtcname)
                 return false;
 
         /* wakeup events could be disabled or not supported */
-        return strncmp(buf, "enabled\n", 8) == 0;
+        return is_prefixed_with(buf, "enabled\n") != NULL;
 }
 
 static NOINLINE void setup_alarm(int fd, time_t *wakeup, time_t rtc_time)
diff --git a/util-linux/swaponoff.c b/util-linux/swaponoff.c
index 75487267b..5cd1fbe70 100644
--- a/util-linux/swaponoff.c
+++ b/util-linux/swaponoff.c
@@ -8,7 +8,7 @@
  */
 
 //usage:#define swapon_trivial_usage
-//usage:       "[-a]" IF_FEATURE_SWAPON_DISCARD(" [-d[POL]]") 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"
@@ -16,15 +16,17 @@
 //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"
 //usage:        )
 //usage:
 //usage:#define swapoff_trivial_usage
-//usage:       "[-a] [DEVICE]"
+//usage:       "[-a] [-e] [DEVICE]"
 //usage:#define swapoff_full_usage "\n\n"
 //usage:       "Stop swapping on DEVICE\n"
 //usage:     "\n        -a      Stop swapping on all swap devices"
+//usage:     "\n        -e      Silently skip devices that do not exist"
 
 #include "libbb.h"
 #include <mntent.h>
@@ -77,15 +79,18 @@ struct globals {
 /* 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)
@@ -95,6 +100,8 @@ static int swap_enable_disable(char *device)
         struct stat st;
 
         resolve_mount_spec(&device);
+        if (!OPT_IFEXISTS)
+                xstat(device, &st);
 
         if (do_swapoff) {
                 err = swapoff(device);
@@ -112,7 +119,8 @@ static int swap_enable_disable(char *device)
                         }
                         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 */
+                        quiet = (OPT_ALL && errno == EBUSY) || (OPT_IFEXISTS && errno == ENOENT);
                 }
         }
 
@@ -229,7 +237,7 @@ static int do_all_in_proc_swaps(void)
         return err;
 }
 
-#define OPTSTR_SWAPON "a" \
+#define OPTSTR_SWAPON "ae" \
         IF_FEATURE_SWAPON_DISCARD("d::") \
         IF_FEATURE_SWAPON_PRI("p:")
 
@@ -242,7 +250,7 @@ int swap_on_off_main(int argc UNUSED_PARAM, char **argv)
 
         INIT_G();
 
-        getopt32(argv, do_swapoff ? "a" : OPTSTR_SWAPON
+        getopt32(argv, do_swapoff ? "ae" : OPTSTR_SWAPON
                         IF_FEATURE_SWAPON_DISCARD(, &discard)
                         IF_FEATURE_SWAPON_PRI(, &prio)
         );
diff --git a/util-linux/volume_id/get_devname.c b/util-linux/volume_id/get_devname.c
index 0c6bdfddf..53bdbdf09 100644
--- a/util-linux/volume_id/get_devname.c
+++ b/util-linux/volume_id/get_devname.c
@@ -302,9 +302,9 @@ int resolve_mount_spec(char **fsname)
 {
         char *tmp = *fsname;
 
-        if (strncmp(*fsname, "UUID=", 5) == 0)
+        if (is_prefixed_with(*fsname, "UUID="))
                 tmp = get_devname_from_uuid(*fsname + 5);
-        else if (strncmp(*fsname, "LABEL=", 6) == 0)
+        else if (is_prefixed_with(*fsname, "LABEL=") == 0)
                 tmp = get_devname_from_label(*fsname + 6);
 
         if (tmp == *fsname)