swapon: add -o <list> for compatibility with mount

The new option allows to specify swap options by fstab compatible
string. The concept is the same as for mount(8).

   swapon -o pri=1,discard=pages,nofail /dev/sda2

The advantage is that tools (like systmed) that parses fstab can call
swapon without translation from fstab options to swapon(8) command
line options.

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/swapon.8 b/sys-utils/swapon.8
index 34118fbf41caa22a3ed6fdb7b1de523e7d749913..e88e2f1b27525fee277ffde9e02ce9ed3bd4aad3 100644 (file)
--- a/sys-utils/swapon.8
+++ b/sys-utils/swapon.8
@@ -130,6 +130,18 @@ Use the partition that has the specified
 .I /proc/partitions
 is needed.)
 .TP
+.BR \-o , " \-\-options " \fIopts\fP
+Specify swap options by fstab compatible comma separated string. For example:
+.RS
+.RS
+.sp
+.B "swapon -o pri=1,discard=pages,nofail /dev/sda2"
+.sp
+.RE
+The \fIopts\fP string is evaluated as the last and overrides all another
+options.
+.RE
+.TP
 .BR \-p , " \-\-priority " \fIpriority\fP
 Specify the priority of the swap device.
 .I priority
@@ -149,10 +161,8 @@ Display swap usage summary by device.  Equivalent to "cat /proc/swaps".
 Not available before Linux 2.1.25.  This output format is DEPRECATED in favour
 of \fB\-\-show\fR that provides better control on output data.
 .TP
-.BR \-\-show " [\fIcolumn\fR, ...]"
-Display definable device table similar to
-.B \-\-summary
-output.  See
+.BR " \-\-show" [ =\fIcolumn\fR]
+Display definable table of swap areas. See
 .B \-\-help
 output for a list of available columns.
 .TP

diff --git a/sys-utils/swapon.c b/sys-utils/swapon.c
index 1170f9e2e4642e025432ae67f0f0dd87efa70391..8609ea242ae7554ef5aab00be2fd08c4bb258c02 100644 (file)
--- a/sys-utils/swapon.c
+++ b/sys-utils/swapon.c
@@ -21,6 +21,7 @@
 #include "pathnames.h"
 #include "xalloc.h"
 #include "strutils.h"
+#include "optutils.h"
 #include "closestream.h"
 
 #include "swapheader.h"
@@ -640,6 +641,42 @@ static int swapon_by_uuid(const char *uuid, int prio, int dsc)
                         cannot_find(uuid);
 }
 
+/* -o <options> or fstab */
+static int parse_options(const char *optstr,
+                        int *priority, int *discard, int *nofail)
+{
+       char *arg = NULL;
+
+       assert(optstr);
+       assert(priority);
+       assert(discard);
+       assert(nofail);
+
+       if (mnt_optstr_get_option(optstr, "nofail", NULL, 0) == 0)
+               *nofail = 1;
+
+       if (mnt_optstr_get_option(optstr, "discard", &arg, NULL) == 0) {
+               *discard |= SWAP_FLAG_DISCARD;
+
+               if (arg) {
+                       /* only single-time discards are wanted */
+                       if (strcmp(arg, "once") == 0)
+                               *discard |= SWAP_FLAG_DISCARD_ONCE;
+
+                       /* do discard for every released swap page */
+                       if (strcmp(arg, "pages") == 0)
+                               *discard |= SWAP_FLAG_DISCARD_PAGES;
+                       }
+       }
+
+       arg = NULL;
+       if (mnt_optstr_get_option(optstr, "pri", &arg, NULL) == 0 && arg)
+               *priority = atoi(arg);
+
+       return 0;
+}
+
+
 static int swapon_all(void)
 {
        struct libmnt_table *tb = get_fstab();
@@ -657,26 +694,14 @@ static int swapon_all(void)
        while (mnt_table_find_next_fs(tb, itr, match_swap, NULL, &fs) == 0) {
                /* defaults */
                int pri = priority, dsc = discard, nofail = ifexists;
-               char *p, *src, *dscarg;
+               const char *opts, *src;
 
                if (mnt_fs_get_option(fs, "noauto", NULL, NULL) == 0)
                        continue;
-               if (mnt_fs_get_option(fs, "discard", &dscarg, NULL) == 0) {
-                       dsc |= SWAP_FLAG_DISCARD;
-                       if (dscarg) {
-                               /* only single-time discards are wanted */
-                               if (strcmp(dscarg, "once") == 0)
-                                       dsc |= SWAP_FLAG_DISCARD_ONCE;
-
-                               /* do discard for every released swap page */
-                               if (strcmp(dscarg, "pages") == 0)
-                                       dsc |= SWAP_FLAG_DISCARD_PAGES;
-                       }
-               }
-               if (mnt_fs_get_option(fs, "nofail", NULL, NULL) == 0)
-                       nofail = 1;
-               if (mnt_fs_get_option(fs, "pri", &p, NULL) == 0 && p)
-                       pri = atoi(p);
+
+               opts = mnt_fs_get_options(fs);
+               if (opts)
+                       parse_options(opts, &pri, &dsc, &nofail);
 
                src = mnt_resolve_spec(mnt_fs_get_source(fs), mntcache);
                if (!src) {
@@ -694,6 +719,7 @@ static int swapon_all(void)
        return status;
 }
 
+
 static void __attribute__ ((__noreturn__)) usage(FILE * out)
 {
        size_t i;
@@ -706,6 +732,7 @@ static void __attribute__ ((__noreturn__)) usage(FILE * out)
                " -d, --discard[=<policy>] enable swap discards, if supported by device\n"
                " -e, --ifexists           silently skip devices that do not exist\n"
                " -f, --fixpgsz            reinitialize the swap space if necessary\n"
+               " -o, --options <list>     comma-separated list of swap options\n"
                " -p, --priority <prio>    specify the priority of the swap device\n"
                " -s, --summary            display summary about used swap devices (DEPRECATED)\n"
                "     --show[=<columns>]   display summary in definable table\n"
@@ -743,22 +770,24 @@ static void __attribute__ ((__noreturn__)) usage(FILE * out)
 
 int main(int argc, char *argv[])
 {
+       char *options = NULL;
        int status = 0, c;
        int show = 0;
        int bytes = 0;
        size_t i;
 
        enum {
-               SHOW_OPTION = CHAR_MAX + 1,
-               RAW_OPTION,
+               BYTES_OPTION = CHAR_MAX + 1,
                NOHEADINGS_OPTION,
-               BYTES_OPTION
+               RAW_OPTION,
+               SHOW_OPTION
        };
 
        static const struct option long_opts[] = {
                { "priority", 1, 0, 'p' },
                { "discard",  2, 0, 'd' },
                { "ifexists", 0, 0, 'e' },
+               { "options",  2, 0, 'o' },
                { "summary",  0, 0, 's' },
                { "fixpgsz",  0, 0, 'f' },
                { "all",      0, 0, 'a' },
@@ -772,6 +801,15 @@ int main(int argc, char *argv[])
                { NULL, 0, 0, 0 }
        };
 
+       static const ul_excl_t excl[] = {       /* rows and cols in in ASCII order */
+               { 'a','o','s', SHOW_OPTION },
+               { 'a','o', BYTES_OPTION },
+               { 'a','o', NOHEADINGS_OPTION },
+               { 'a','o', RAW_OPTION },
+               { 0 }
+       };
+       int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
+
        setlocale(LC_ALL, "");
        bindtextdomain(PACKAGE, LOCALEDIR);
        textdomain(PACKAGE);
@@ -780,8 +818,11 @@ int main(int argc, char *argv[])
        mnt_init_debug(0);
        mntcache = mnt_new_cache();
 
-       while ((c = getopt_long(argc, argv, "ahd::efp:svVL:U:",
+       while ((c = getopt_long(argc, argv, "ahd::efo:p:svVL:U:",
                                long_opts, NULL)) != -1) {
+
+               err_exclusive_options(c, long_opts, excl, excl_st);
+
                switch (c) {
                case 'a':               /* all */
                        ++all;
@@ -789,6 +830,9 @@ int main(int argc, char *argv[])
                case 'h':               /* help */
                        usage(stdout);
                        break;
+               case 'o':
+                       options = optarg;
+                       break;
                case 'p':               /* priority */
                        priority = strtos16_or_err(optarg,
                                           _("failed to parse priority"));
@@ -876,6 +920,9 @@ int main(int argc, char *argv[])
        if (all)
                status |= swapon_all();
 
+       if (options)
+               parse_options(options, &priority, &discard, &ifexists);
+
        for (i = 0; i < numof_labels(); i++)
                status |= swapon_by_label(get_label(i), priority, discard);