+static char* add_option(char* options, const char* name, const char* value)
+{
+ size_t size;
+
+ if (value)
+ size = strlen(options) + strlen(name) + strlen(value) + 3;
+ else
+ size = strlen(options) + strlen(name) + 2;
+
+ options = realloc(options, size);
+ if (options == NULL)
+ {
+ exfat_error("failed to reallocate options string");
+ return NULL;
+ }
+ strcat(options, ",");
+ strcat(options, name);
+ if (value)
+ {
+ strcat(options, "=");
+ strcat(options, value);
+ }
+ return options;
+}
+
+static char* add_fsname_option(char* options, const char* spec)
+{
+ char spec_abs[PATH_MAX];
+
+ if (realpath(spec, spec_abs) == NULL)
+ {
+ free(options);
+ exfat_error("failed to get absolute path for `%s'", spec);
+ return NULL;
+ }
+ return add_option(options, "fsname", spec_abs);
+}
+
+static char* add_user_option(char* options)
+{
+ struct passwd* pw;
+
+ if (getuid() == 0)
+ return options;
+
+ pw = getpwuid(getuid());
+ if (pw == NULL || pw->pw_name == NULL)
+ {
+ free(options);
+ exfat_error("failed to determine username");
+ return NULL;
+ }
+ return add_option(options, "user", pw->pw_name);
+}
+
+static char* add_blksize_option(char* options, long cluster_size)
+{
+ long page_size = sysconf(_SC_PAGESIZE);
+ char blksize[20];
+
+ if (page_size < 1)
+ page_size = 0x1000;
+
+ snprintf(blksize, sizeof(blksize), "%ld", MIN(page_size, cluster_size));
+ return add_option(options, "blksize", blksize);
+}
+
+static char* add_fuse_options(char* options, const char* spec)
+{
+ options = add_fsname_option(options, spec);
+ if (options == NULL)
+ return NULL;
+ options = add_user_option(options);
+ if (options == NULL)
+ return NULL;
+ options = add_blksize_option(options, CLUSTER_SIZE(*ef.sb));
+ if (options == NULL)
+ return NULL;
+
+ return options;
+}
+