+static int lookup_device(char *path, unsigned int maj, unsigned int min)
+{
+ struct dirent *dir;
+ struct stat st;
+ int found = 0;
+ DIR *D;
+
+ D = opendir(path);
+ if (!D)
+ return 0;
+
+ while ((dir = readdir(D)) != NULL) {
+ char full_path[256];
+
+ if (!strcmp(dir->d_name, ".") || !strcmp(dir->d_name, ".."))
+ continue;
+
+ sprintf(full_path, "%s/%s", path, dir->d_name);
+ if (lstat(full_path, &st) == -1) {
+ perror("lstat");
+ break;
+ }
+
+ if (S_ISDIR(st.st_mode)) {
+ found = lookup_device(full_path, maj, min);
+ if (found) {
+ strcpy(path, full_path);
+ break;
+ }
+ }
+
+ if (!S_ISBLK(st.st_mode))
+ continue;
+
+ if (maj == major(st.st_rdev) && min == minor(st.st_rdev)) {
+ dprint(FD_BLKTRACE, "device lookup: %d/%d\n", maj, min);
+ strcpy(path, full_path);
+ found = 1;
+ break;
+ }
+ }
+
+ closedir(D);
+ return found;
+}
+
+#define FMINORBITS 20
+#define FMINORMASK ((1U << FMINORBITS) - 1)
+#define FMAJOR(dev) ((unsigned int) ((dev) >> FMINORBITS))
+#define FMINOR(dev) ((unsigned int) ((dev) & FMINORMASK))
+
+static void trace_add_open_event(struct thread_data *td, int fileno)
+{
+ struct io_piece *ipo;
+
+ ipo = calloc(1, sizeof(*ipo));
+
+ ipo->ddir = DDIR_INVAL;
+ ipo->fileno = fileno;
+ ipo->file_action = FIO_LOG_OPEN_FILE;
+ flist_add_tail(&ipo->list, &td->io_log_list);
+}
+
+static void trace_add_file(struct thread_data *td, __u32 device)
+{
+ static unsigned int last_maj, last_min;
+ unsigned int maj = FMAJOR(device);
+ unsigned int min = FMINOR(device);
+ struct fio_file *f;
+ char dev[256];
+ unsigned int i;
+
+ if (last_maj == maj && last_min == min)
+ return;
+
+ last_maj = maj;
+ last_min = min;
+
+ /*
+ * check for this file in our list
+ */
+ for_each_file(td, f, i)
+ if (f->major == maj && f->minor == min)
+ return;
+
+ strcpy(dev, "/dev");
+ if (lookup_device(dev, maj, min)) {
+ int fileno;
+
+ dprint(FD_BLKTRACE, "add devices %s\n", dev);
+ fileno = add_file(td, dev);
+ trace_add_open_event(td, fileno);
+ }
+}
+
+/*
+ * Store blk_io_trace data in an ipo for later retrieval.
+ */