Add utility function to append root to path

[elogind.git] / src / shared / path-util.c

diff --git a/src/shared/path-util.c b/src/shared/path-util.c
index d193494afb266b94d771d2fc44128c45c47f7e4d..5bc5012fe89ed61900f038dd260d348593ec58fd 100644 (file)
--- a/src/shared/path-util.c
+++ b/src/shared/path-util.c
@@ -435,6 +435,22 @@ bool path_equal(const char *a, const char *b) {
         }
 }
 
+char* path_join(const char *root, const char *path, const char *rest) {
+        assert(path);
+
+        if (!isempty(root))
+                return strjoin(root, "/",
+                               path[0] == '/' ? path+1 : path,
+                               rest ? "/" : NULL,
+                               rest && rest[0] == '/' ? rest+1 : rest,
+                               NULL);
+        else
+                return strjoin(path,
+                               rest ? "/" : NULL,
+                               rest && rest[0] == '/' ? rest+1 : rest,
+                               NULL);
+}
+
 int path_is_mount_point(const char *t, bool allow_symlink) {
 
         union file_handle_union h = {
@@ -442,7 +458,7 @@ int path_is_mount_point(const char *t, bool allow_symlink) {
         };
 
         int mount_id, mount_id_parent;
-        char *parent;
+        _cleanup_free_ char *parent = NULL;
         struct stat a, b;
         int r;
 
@@ -473,7 +489,6 @@ int path_is_mount_point(const char *t, bool allow_symlink) {
 
         h.handle.handle_bytes = MAX_HANDLE_SZ;
         r = name_to_handle_at(AT_FDCWD, parent, &h.handle, &mount_id_parent, 0);
-        free(parent);
         if (r < 0) {
                 /* The parent can't do name_to_handle_at() but the
                  * directory we are interested in can? If so, it must
@@ -504,7 +519,6 @@ fallback:
                 return r;
 
         r = lstat(parent, &b);
-        free(parent);
         if (r < 0)
                 return -errno;
 
@@ -543,7 +557,7 @@ int path_is_os_tree(const char *path) {
 int find_binary(const char *name, char **filename) {
         assert(name);
 
-        if (strchr(name, '/')) {
+        if (is_path(name)) {
                 if (access(name, X_OK) < 0)
                         return -errno;
 
@@ -628,8 +642,25 @@ bool paths_check_timestamp(const char* const* paths, usec_t *timestamp, bool upd
 }
 
 int fsck_exists(const char *fstype) {
+        _cleanup_free_ char *p = NULL, *d = NULL;
         const char *checker;
+        int r;
 
         checker = strappenda("fsck.", fstype);
-        return find_binary(checker, NULL);
+
+        r = find_binary(checker, &p);
+        if (r < 0)
+                return r;
+
+        /* An fsck that is linked to /bin/true is a non-existent
+         * fsck */
+
+        r = readlink_malloc(p, &d);
+        if (r >= 0 &&
+            (path_equal(d, "/bin/true") ||
+             path_equal(d, "/usr/bin/true") ||
+             path_equal(d, "/dev/null")))
+                return -ENOENT;
+
+        return 0;
 }