mountpoint: use single libmount cache for all path resolutions

Move libmount cache initialization to main() and pass it through
the control structure. This allows the cache to be reused across
all mnt_resolve_path() calls, reducing allocations.

Also add cleanup section in main() with goto labels for proper
resource deallocation in a single location.

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

diff --git a/sys-utils/mountpoint.c b/sys-utils/mountpoint.c
index aed1f0fef699ccdd35051fc4cfb41ee3e4f23931..688ee67c65081d94e51852fdd013af97eea7fe8d 100644 (file)
--- a/sys-utils/mountpoint.c
+++ b/sys-utils/mountpoint.c
@@ -40,6 +40,7 @@ struct mountpoint_control {
        char *mnt_target;
        dev_t dev;
        struct stat st;
+       struct libmnt_cache *cache;
        bool    dev_devno,
                fs_devno,
                nofollow,
@@ -62,7 +63,7 @@ static int dir_to_device_statmount(struct mountpoint_control *ctl)
        uint64_t id = 0;
        int rc;
 
-       cn = mnt_resolve_path(ctl->path, NULL);
+       cn = mnt_resolve_path(ctl->path, ctl->cache);
 
        rc = mnt_id_from_path(cn ? cn : ctl->path, &id, NULL);
        if (rc)
@@ -96,7 +97,6 @@ static int dir_to_device_statmount(struct mountpoint_control *ctl)
                rc = 0; /* is a mountpoint */
        }
 done:
-       free(cn);
        mnt_unref_fs(fs);
        return rc;
 }
@@ -112,7 +112,6 @@ static int dir_to_device(struct mountpoint_control *ctl)
 {
        struct libmnt_table *tb;
        struct libmnt_fs *fs;
-       struct libmnt_cache *cache;
        int rc;
 
 #ifdef HAVE_STATMOUNT_API
@@ -133,13 +132,13 @@ static int dir_to_device(struct mountpoint_control *ctl)
                 * is independent on /proc, but not able to detect bind mounts.
                 */
                struct stat pst;
-               char buf[PATH_MAX], *cn;
+               char buf[PATH_MAX];
+               const char *cn;
                int len;
 
-               cn = mnt_resolve_path(ctl->path, NULL); /* canonicalize */
+               cn = mnt_resolve_path(ctl->path, ctl->cache);   /* canonicalize */
 
                len = snprintf(buf, sizeof(buf), "%s/..", cn ? cn : ctl->path);
-               free(cn);
 
                if (len < 0 || (size_t) len >= sizeof(buf))
                        return -EINVAL;
@@ -157,9 +156,7 @@ static int dir_to_device(struct mountpoint_control *ctl)
        }
 
        /* to canonicalize all necessary paths */
-       cache = mnt_new_cache();
-       mnt_table_set_cache(tb, cache);
-       mnt_unref_cache(cache);
+       mnt_table_set_cache(tb, ctl->cache);
 
        fs = mnt_table_find_target(tb, ctl->path, MNT_ITER_BACKWARD);
        if (fs && mnt_fs_get_target(fs)) {
@@ -287,25 +284,31 @@ int main(int argc, char **argv)
                return MOUNTPOINT_EXIT_NOMNT;
        }
 
+       ctl.cache = mnt_new_cache();
+       if (!ctl.cache)
+               err(EXIT_FAILURE, _("failed to initialize libmount cache"));
+
        rc = dir_to_device(&ctl);
        if (rc < 0) {
                if (!ctl.quiet) {
                        errno = -rc;
                        warn("%s", ctl.path);
                }
-               return EXIT_FAILURE;
+               rc = EXIT_FAILURE;
+               goto done;
        }
 
        if (ctl.show) {
                printf("%s\n", ctl.mnt_target);
-               free(ctl.mnt_target);
-               return EXIT_SUCCESS;
+               rc = EXIT_SUCCESS;
+               goto done;
        }
 
        if (rc == 1) {
                if (!ctl.quiet)
                        printf(_("%s is not a mountpoint\n"), ctl.path);
-               return MOUNTPOINT_EXIT_NOMNT;
+               rc = MOUNTPOINT_EXIT_NOMNT;
+               goto done;
        }
 
        if (ctl.fs_devno)
@@ -313,5 +316,10 @@ int main(int argc, char **argv)
        else if (!ctl.quiet)
                printf(_("%s is a mountpoint\n"), ctl.path);
 
-       return EXIT_SUCCESS;
+       rc = EXIT_SUCCESS;
+
+done:
+       free(ctl.mnt_target);
+       mnt_unref_cache(ctl.cache);
+       return rc;
 }