mkswap: device open code refactoring

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

diff --git a/disk-utils/mkswap.c b/disk-utils/mkswap.c
index 7a4b53e84af7ab4679a047cb4532f54c930eb88a..1401f668f4ab1084859b275f41bd15d19c92c301 100644 (file)
--- a/disk-utils/mkswap.c
+++ b/disk-utils/mkswap.c
@@ -53,8 +53,9 @@ struct mkswap_control {
        struct swap_header_v1_2 *hdr;           /* swap header */
        void                    *signature_page;/* buffer with swap header */
 
-       char                    *device_name;
-       int                     fd;
+       char                    *devname;       /* device or file name */
+       struct stat             devstat;        /* stat() result */
+       int                     fd;             /* swap file descriptor */
 
        unsigned long long      npages;         /* number of pages */
        unsigned long           nbadpages;      /* number of bad pages */
@@ -99,16 +100,15 @@ static void deinit_signature_page(struct mkswap_control *ctl)
        ctl->signature_page = NULL;
 }
 
-static void
-write_signature(const struct mkswap_control *ctl)
+static void write_signature(const struct mkswap_control *ctl)
 {
        char *sp = (char *) ctl->signature_page;
 
+       assert(sp);
        strncpy(sp + ctl->pagesize - SWAP_SIGNATURE_SZ, SWAP_SIGNATURE, SWAP_SIGNATURE_SZ);
 }
 
-static void
-write_uuid_and_label(const struct mkswap_control *ctl)
+static void write_uuid_and_label(const struct mkswap_control *ctl)
 {
        assert(ctl);
        assert(ctl->hdr);
@@ -203,15 +203,14 @@ static void check_blocks(struct mkswap_control *ctl)
 }
 
 /* return size in pages */
-static unsigned long long
-get_size(const struct mkswap_control *ctl)
+static unsigned long long get_size(const struct mkswap_control *ctl)
 {
        int fd;
        unsigned long long size;
 
-       fd = open(ctl->device_name, O_RDONLY);
+       fd = open(ctl->devname, O_RDONLY);
        if (fd < 0)
-               err(EXIT_FAILURE, _("cannot open %s"), ctl->device_name);
+               err(EXIT_FAILURE, _("cannot open %s"), ctl->devname);
        if (blkdev_get_size(fd, &size) == 0)
                size /= ctl->pagesize;
 
@@ -220,8 +219,7 @@ get_size(const struct mkswap_control *ctl)
 }
 
 #ifdef HAVE_LIBBLKID
-static blkid_probe
-new_prober(const struct mkswap_control *ctl)
+static blkid_probe new_prober(const struct mkswap_control *ctl)
 {
        blkid_probe pr = blkid_new_probe();
        if (!pr)
@@ -232,8 +230,33 @@ new_prober(const struct mkswap_control *ctl)
 }
 #endif
 
-static void
-wipe_device(struct mkswap_control *ctl)
+static void open_device(struct mkswap_control *ctl)
+{
+       assert(ctl);
+       assert(ctl->devname);
+
+       if (stat(ctl->devname, &ctl->devstat) < 0)
+               err(EXIT_FAILURE, _("stat failed %s"), ctl->devname);
+
+       if (S_ISBLK(ctl->devstat.st_mode))
+               ctl->fd = open(ctl->devname, O_RDWR | O_EXCL);
+       else {
+               if (ctl->check) {
+                       ctl->check = 0;
+                       warnx(_("warning: checking bad blocks from swap file is not supported: %s"),
+                               ctl->devname);
+               }
+               ctl->fd = open(ctl->devname, O_RDWR);
+       }
+       if (ctl->fd < 0)
+               err(EXIT_FAILURE, _("cannot open %s"), ctl->devname);
+
+       if (S_ISBLK(ctl->devstat.st_mode))
+               if (blkdev_is_misaligned(ctl->fd))
+                       warnx(_("warning: %s is misaligned"), ctl->devname);
+}
+
+static void wipe_device(struct mkswap_control *ctl)
 {
        char *type = NULL;
        int zap = 1;
@@ -287,13 +310,13 @@ wipe_device(struct mkswap_control *ctl)
                        const char *data = NULL;
 
                        if (blkid_probe_lookup_value(pr, "TYPE", &data, NULL) == 0 && data)
-                               warnx(_("%s: warning: wiping old %s signature."), ctl->device_name, data);
+                               warnx(_("%s: warning: wiping old %s signature."), ctl->devname, data);
                        blkid_do_wipe(pr, 0);
                }
 #endif
        } else {
                warnx(_("%s: warning: don't erase bootbits sectors"),
-                       ctl->device_name);
+                       ctl->devname);
                if (type)
                        fprintf(stderr, _("        (%s partition table detected). "), type);
                else
@@ -308,7 +331,6 @@ wipe_device(struct mkswap_control *ctl)
 int
 main(int argc, char **argv) {
        struct mkswap_control ctl = { .fd = -1 };
-       struct stat statbuf;
        int c;
        unsigned long long goodpages;
        unsigned long long sz;
@@ -374,7 +396,7 @@ main(int argc, char **argv) {
                }
        }
        if (optind < argc)
-               ctl.device_name = argv[optind++];
+               ctl.devname = argv[optind++];
        if (optind < argc)
                block_count = argv[optind++];
        if (optind != argc) {
@@ -393,7 +415,7 @@ main(int argc, char **argv) {
 
        init_signature_page(&ctl);      /* get pagesize and allocate signature page */
 
-       if (!ctl.device_name) {
+       if (!ctl.devname) {
                warnx(_("error: Nowhere to set up swap on?"));
                usage(stderr);
        }
@@ -423,28 +445,13 @@ main(int argc, char **argv) {
                        ctl.npages * ctl.pagesize / 1024);
        }
 
-       if (is_mounted(ctl.device_name))
+       if (is_mounted(ctl.devname))
                errx(EXIT_FAILURE, _("error: "
                        "%s is mounted; will not make swapspace"),
-                       ctl.device_name);
+                       ctl.devname);
+
+       open_device(&ctl);
 
-       if (stat(ctl.device_name, &statbuf) < 0)
-               err(EXIT_FAILURE, _("stat failed %s"), ctl.device_name);
-       if (S_ISBLK(statbuf.st_mode))
-               ctl.fd = open(ctl.device_name, O_RDWR | O_EXCL);
-       else {
-               if (ctl.check) {
-                       ctl.check = 0;
-                       warnx(_("warning: checking bad blocks from swap file is not supported: %s"),
-                               ctl.device_name);
-               }
-               ctl.fd = open(ctl.device_name, O_RDWR);
-       }
-       if (ctl.fd < 0)
-               err(EXIT_FAILURE, _("cannot open %s"), ctl.device_name);
-       if (S_ISBLK(statbuf.st_mode))
-               if (blkdev_is_misaligned(ctl.fd))
-                       warnx(_("warning: %s is misaligned"), ctl.device_name);
        if (ctl.check)
                check_blocks(&ctl);
 
@@ -472,12 +479,12 @@ main(int argc, char **argv) {
                                    ctl.pagesize - offset) == -1)
                err(EXIT_FAILURE,
                        _("%s: unable to write signature page"),
-                       ctl.device_name);
+                       ctl.devname);
 
        deinit_signature_page(&ctl);
 
 #ifdef HAVE_LIBSELINUX
-       if (S_ISREG(statbuf.st_mode) && is_selinux_enabled() > 0) {
+       if (S_ISREG(ctl.devstat.st_mode) && is_selinux_enabled() > 0) {
                security_context_t context_string;
                security_context_t oldcontext;
                context_t newcontext;
@@ -486,8 +493,8 @@ main(int argc, char **argv) {
                        if (errno != ENODATA)
                                err(EXIT_FAILURE,
                                        _("%s: unable to obtain selinux file label"),
-                                       ctl.device_name);
-                       if (matchpathcon(ctl.device_name, statbuf.st_mode, &oldcontext))
+                                       ctl.devname);
+                       if (matchpathcon(ctl.devname, ctl.devstat.st_mode, &oldcontext))
                                errx(EXIT_FAILURE, _("unable to matchpathcon()"));
                }
                if (!(newcontext = context_new(oldcontext)))
@@ -500,7 +507,7 @@ main(int argc, char **argv) {
                if (strcmp(context_string, oldcontext)!=0) {
                        if (fsetfilecon(ctl.fd, context_string))
                                err(EXIT_FAILURE, _("unable to relabel %s to %s"),
-                                               ctl.device_name, context_string);
+                                               ctl.devname, context_string);
                }
                context_free(newcontext);
                freecon(oldcontext);