mountpoint: add struct mountpoint_control

This unifies variable names in different functions, and removes redundant
stat() calls.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/sys-utils/mountpoint.c b/sys-utils/mountpoint.c
index 3919ab74818f93366977a347b92b32aa64b04298..4161d206f54e27660a1a9eb55cdfc360e18f9d80 100644 (file)
--- a/sys-utils/mountpoint.c
+++ b/sys-utils/mountpoint.c
@@ -40,9 +40,17 @@
 #include "closestream.h"
 #include "pathnames.h"
 
-static int quiet;
+struct mountpoint_control {
+       char *path;
+       dev_t dev;
+       struct stat st;
+       unsigned int
+               dev_devno:1,
+               fs_devno:1,
+               quiet:1;
+};
 
-static int dir_to_device(const char *spec, dev_t *dev)
+static int dir_to_device(struct mountpoint_control *ctl)
 {
        struct libmnt_table *tb = mnt_new_table_from_file(_PATH_PROC_MOUNTINFO);
        struct libmnt_fs *fs;
@@ -54,16 +62,13 @@ static int dir_to_device(const char *spec, dev_t *dev)
                 * Fallback. Traditional way to detect mountpoints. This way
                 * is independent on /proc, but not able to detect bind mounts.
                 */
-               struct stat pst, st;
+               struct stat pst;
                char buf[PATH_MAX], *cn;
                int len;
 
-               if (stat(spec, &st) != 0)
-                       return -1;
-
-               cn = mnt_resolve_path(spec, NULL);      /* canonicalize */
+               cn = mnt_resolve_path(ctl->path, NULL); /* canonicalize */
 
-               len = snprintf(buf, sizeof(buf), "%s/..", cn ? cn : spec);
+               len = snprintf(buf, sizeof(buf), "%s/..", cn ? cn : ctl->path);
                free(cn);
 
                if (len < 0 || (size_t) len + 1 > sizeof(buf))
@@ -71,9 +76,9 @@ static int dir_to_device(const char *spec, dev_t *dev)
                if (stat(buf, &pst) !=0)
                        return -1;
 
-               if ((st.st_dev != pst.st_dev) ||
-                   (st.st_dev == pst.st_dev && st.st_ino == pst.st_ino)) {
-                       *dev = st.st_dev;
+               if ((ctl->st.st_dev != pst.st_dev) ||
+                   (ctl->st.st_dev == pst.st_dev && ctl->st.st_ino == pst.st_ino)) {
+                       ctl->dev = ctl->st.st_dev;
                        return 0;
                }
 
@@ -85,9 +90,9 @@ static int dir_to_device(const char *spec, dev_t *dev)
        mnt_table_set_cache(tb, cache);
        mnt_unref_cache(cache);
 
-       fs = mnt_table_find_target(tb, spec, MNT_ITER_BACKWARD);
+       fs = mnt_table_find_target(tb, ctl->path, MNT_ITER_BACKWARD);
        if (fs && mnt_fs_get_target(fs)) {
-               *dev = mnt_fs_get_devno(fs);
+               ctl->dev = mnt_fs_get_devno(fs);
                rc = 0;
        }
 
@@ -95,20 +100,14 @@ static int dir_to_device(const char *spec, dev_t *dev)
        return rc;
 }
 
-static int print_devno(const char *devname, struct stat *st)
+static int print_devno(const struct mountpoint_control *ctl)
 {
-       struct stat stbuf;
-
-       if (!st && stat(devname, &stbuf) == 0)
-               st = &stbuf;
-       if (!st)
-               return -1;
-       if (!S_ISBLK(st->st_mode)) {
-               if (!quiet)
-                       warnx(_("%s: not a block device"), devname);
+       if (!S_ISBLK(ctl->st.st_mode)) {
+               if (!ctl->quiet)
+                       warnx(_("%s: not a block device"), ctl->path);
                return -1;
        }
-       printf("%u:%u\n", major(st->st_rdev), minor(st->st_rdev));
+       printf("%u:%u\n", major(ctl->st.st_rdev), minor(ctl->st.st_rdev));
        return 0;
 }
 
@@ -133,9 +132,8 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
 
 int main(int argc, char **argv)
 {
-       int c, fs_devno = 0, dev_devno = 0, rc = 0;
-       char *spec;
-       struct stat st;
+       int c, rc = 0;
+       struct mountpoint_control ctl = { 0 };
 
        static const struct option longopts[] = {
                { "quiet", 0, 0, 'q' },
@@ -157,13 +155,13 @@ int main(int argc, char **argv)
 
                switch(c) {
                case 'q':
-                       quiet = 1;
+                       ctl.quiet = 1;
                        break;
                case 'd':
-                       fs_devno = 1;
+                       ctl.fs_devno = 1;
                        break;
                case 'x':
-                       dev_devno = 1;
+                       ctl.dev_devno = 1;
                        break;
                case 'h':
                        usage(stdout);
@@ -180,27 +178,25 @@ int main(int argc, char **argv)
        if (optind + 1 != argc)
                usage(stderr);
 
-       spec = argv[optind++];
+       ctl.path = argv[optind];
 
-       if (stat(spec, &st)) {
-               if (!quiet)
-                       err(EXIT_FAILURE, "%s", spec);
+       if (stat(ctl.path, &ctl.st)) {
+               if (!ctl.quiet)
+                       err(EXIT_FAILURE, "%s", ctl.path);
                return EXIT_FAILURE;
        }
-       if (dev_devno)
-               rc = print_devno(spec, &st);
+       if (ctl.dev_devno)
+               rc = print_devno(&ctl);
        else {
-               dev_t src;
-
-               if ( dir_to_device(spec, &src)) {
-                       if (!quiet)
-                               printf(_("%s is not a mountpoint\n"), spec);
+               if (dir_to_device(&ctl)) {
+                       if (!ctl.quiet)
+                               printf(_("%s is not a mountpoint\n"), ctl.path);
                        return EXIT_FAILURE;
                }
-               if (fs_devno)
-                       printf("%u:%u\n", major(src), minor(src));
-               else if (!quiet)
-                       printf(_("%s is a mountpoint\n"), spec);
+               if (ctl.fs_devno)
+                       printf("%u:%u\n", major(ctl.dev), minor(ctl.dev));
+               else if (!ctl.quiet)
+                       printf(_("%s is a mountpoint\n"), ctl.path);
        }
 
        return rc ? EXIT_FAILURE : EXIT_SUCCESS;