swapon: simplify ctl->device usage

* use and initialize ctl->{label,uuid,device} by do_swapon() only
* remove ctl->canonic, function arguments are good enough for this

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

diff --git a/sys-utils/swapon.c b/sys-utils/swapon.c
index be8f7718bbf1f34f55eb700603eeeeccf4fc1669..7d68c42d7892d02c1fbc5354006bf01f6376851c 100644 (file)
--- a/sys-utils/swapon.c
+++ b/sys-utils/swapon.c
@@ -101,9 +101,8 @@ struct colinfo infos[] = {
 
 /* control struct */
 struct swapon_ctl {
-       char *device;                   /* device or file to be turned on */
-       char *dev_canonical;            /* canonical path to device */
-       char *options;                  /* fstab-compatible option string */
+       const char *device;             /* device or file to be turned on */
+       const char *options;            /* fstab-compatible option string */
        const char *label;              /* swap label */
        const char *uuid;               /* unique identifier */
        int discard;                    /* discard policy */
@@ -114,7 +113,6 @@ struct swapon_ctl {
        unsigned int
                all:1,                  /* turn on all swap devices */
                bytes:1,                /* display --show in bytes */
-               canonic:1,              /* is device path canonical */
                fix_page_size:1,        /* reinitialize page size */
                no_fail:1,              /* skip devices that do not exist */
                no_heading:1,           /* toggle --show headers */
@@ -303,7 +301,7 @@ static int swap_reinitialize(struct swapon_ctl *ctl)
        }
        warnx(_("%s: reinitializing the swap."), ctl->device);
 
-       switch((pid=fork())) {
+       switch ((pid=fork())) {
        case -1: /* fork error */
                warn(_("fork failed"));
                return -1;
@@ -345,7 +343,7 @@ static int swap_rewrite_signature(const struct swapon_ctl *ctl)
 {
        int fd, rc = -1;
 
-       fd = open(ctl->dev_canonical, O_WRONLY);
+       fd = open(ctl->device, O_WRONLY);
        if (fd == -1) {
                warn(_("cannot open %s"), ctl->device);
                return -1;
@@ -455,10 +453,10 @@ static void swap_get_info(struct swapon_ctl *ctl, const char *hdr)
 {
        struct swap_header_v1_2 *s = (struct swap_header_v1_2 *) hdr;
 
-       if (s && *s->volume_name && ctl->label)
+       if (s && *s->volume_name)
                ctl->label = xstrdup(s->volume_name);
 
-       if (s && *s->uuid && ctl->uuid) {
+       if (s && *s->uuid) {
                const unsigned char *u = s->uuid;
                char str[37];
 
@@ -481,7 +479,7 @@ static int swapon_checks(struct swapon_ctl *ctl)
        unsigned long long devsize = 0;
        int permMask;
 
-       fd = open(ctl->dev_canonical, O_RDONLY);
+       fd = open(ctl->device, O_RDONLY);
        if (fd == -1) {
                warn(_("cannot open %s"), ctl->device);
                goto err;
@@ -575,20 +573,23 @@ err:
        return -1;
 }
 
-static int do_swapon(struct swapon_ctl *ctl)
+static int do_swapon(struct swapon_ctl *ctl, const char *spec, int canonic)
 {
        int status;
        int flags = 0;
 
+       /* all initilized by do_swapon() */
+       ctl->device = ctl->label = ctl->uuid = NULL;
+
        if (ctl->verbose)
                printf(_("swapon %s\n"), ctl->device);
 
-       if (!ctl->canonic) {
-               ctl->dev_canonical = mnt_resolve_spec(ctl->device, mntcache);
-               if (!ctl->dev_canonical)
-                       return cannot_find(ctl->device);
+       if (!canonic) {
+               ctl->device = mnt_resolve_spec(spec, mntcache);
+               if (!ctl->device)
+                       return cannot_find(spec);
        } else
-               ctl->dev_canonical = ctl->device;
+               ctl->device = spec;
 
        if (swapon_checks(ctl))
                return -1;
@@ -619,23 +620,23 @@ static int do_swapon(struct swapon_ctl *ctl)
                        flags |= ctl->discard;
        }
 
-       status = swapon(ctl->dev_canonical, flags);
+       status = swapon(ctl->device, flags);
        if (status < 0)
                warn(_("%s: swapon failed"), ctl->device);
 
        return status;
 }
 
-static int swapon_by_label(struct swapon_ctl *ctl)
+static int swapon_by_label(struct swapon_ctl *ctl, const char *label)
 {
-       ctl->device = mnt_resolve_tag("LABEL", ctl->label, mntcache);
-       return ctl->device ? do_swapon(ctl) :  cannot_find(ctl->label);
+       char *device = mnt_resolve_tag("LABEL", label, mntcache);
+       return device ? do_swapon(ctl, device, TRUE) :  cannot_find(label);
 }
 
-static int swapon_by_uuid(struct swapon_ctl *ctl)
+static int swapon_by_uuid(struct swapon_ctl *ctl, const char *uuid)
 {
-       ctl->device = mnt_resolve_tag("UUID", ctl->uuid, mntcache);
-       return ctl->device ? do_swapon(ctl) : cannot_find(ctl->uuid);
+       char *device = mnt_resolve_tag("UUID", uuid, mntcache);
+       return device ? do_swapon(ctl, device, TRUE) : cannot_find(uuid);
 }
 
 /* -o <options> or fstab */
@@ -690,6 +691,7 @@ static int swapon_all(struct swapon_ctl *ctl)
        while (mnt_table_find_next_fs(tb, itr, match_swap, NULL, &fs) == 0) {
                /* defaults */
                const char *opts;
+               const char *device;
 
                if (mnt_fs_get_option(fs, "noauto", NULL, NULL) == 0)
                        continue;
@@ -698,16 +700,16 @@ static int swapon_all(struct swapon_ctl *ctl)
                if (opts)
                        parse_options(ctl);
 
-               ctl->device = mnt_resolve_spec(mnt_fs_get_source(fs), mntcache);
-               if (!ctl->device) {
+               device = mnt_resolve_spec(mnt_fs_get_source(fs), mntcache);
+               if (!device) {
                        if (!ctl->no_fail)
                                status |= cannot_find(mnt_fs_get_source(fs));
                        continue;
                }
 
-               if (!is_active_swap(ctl->device) &&
-                   (!ctl->no_fail || !access(ctl->device, R_OK)))
-                       status |= do_swapon(ctl);
+               if (!is_active_swap(device) &&
+                   (!ctl->no_fail || !access(device, R_OK)))
+                       status |= do_swapon(ctl, device, TRUE);
        }
 
        mnt_free_iter(itr);
@@ -804,7 +806,7 @@ int main(int argc, char *argv[])
        };
        int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
 
-       struct swapon_ctl ctl = { .priority = -1, .canonic = 1, 0 };
+       struct swapon_ctl ctl = { .priority = -1 };
 
        setlocale(LC_ALL, "");
        bindtextdomain(PACKAGE, LOCALEDIR);
@@ -919,22 +921,14 @@ int main(int argc, char *argv[])
        if (ctl.options)
                parse_options(&ctl);
 
-       for (i = 0; i < numof_labels(); i++) {
-               ctl.label = get_label(i);
-               status |= swapon_by_label(&ctl);
-       }
+       for (i = 0; i < numof_labels(); i++)
+               status |= swapon_by_label(&ctl, get_label(i));
 
-       for (i = 0; i < numof_uuids(); i++) {
-               ctl.uuid = get_uuid(i);
-               status |= swapon_by_uuid(&ctl);
-       }
-       if (*argv != NULL) {
-               ctl.canonic = 0;
-               while (*argv != NULL) {
-                       ctl.device = *argv++;
-                       status |= do_swapon(&ctl);
-               }
-       }
+       for (i = 0; i < numof_uuids(); i++)
+               status |= swapon_by_uuid(&ctl, get_uuid(i));
+
+       while (*argv != NULL)
+               status |= do_swapon(&ctl, *argv++, FALSE);
 
        free_tables();
        mnt_unref_cache(mntcache);