+/*
+ * filestat engine
+ *
+ * IO engine that doesn't do any IO, just stat files and tracks the latency
+ * of the file stat.
+ */
+#include <stdio.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include "../fio.h"
+
+struct fc_data {
+ enum fio_ddir stat_ddir;
+};
+
+static int stat_file(struct thread_data *td, struct fio_file *f)
+{
+ struct timespec start;
+ int do_lat = !td->o.disable_lat;
+ struct stat statbuf;
+ int ret;
+
+ dprint(FD_FILE, "fd stat %s\n", f->file_name);
+
+ if (f->filetype != FIO_TYPE_FILE) {
+ log_err("fio: only files are supported\n");
+ return 1;
+ }
+ if (!strcmp(f->file_name, "-")) {
+ log_err("fio: can't read/write to stdin/out\n");
+ return 1;
+ }
+
+ if (do_lat)
+ fio_gettime(&start, NULL);
+
+ ret = stat(f->file_name, &statbuf);
+
+ if (ret == -1) {
+ char buf[FIO_VERROR_SIZE];
+ int e = errno;
+
+ snprintf(buf, sizeof(buf), "stat(%s)", f->file_name);
+ td_verror(td, e, buf);
+ return 1;
+ }
+
+ if (do_lat) {
+ struct fc_data *data = td->io_ops_data;
+ uint64_t nsec;
+
+ nsec = ntime_since_now(&start);
+ add_clat_sample(td, data->stat_ddir, nsec, 0, 0);
+ }
+
+ return 0;
+}
+
+static enum fio_q_status queue_io(struct thread_data *td, struct io_u fio_unused *io_u)
+{
+ return FIO_Q_COMPLETED;
+}
+
+static int init(struct thread_data *td)
+{
+ struct fc_data *data;
+
+ data = calloc(1, sizeof(*data));
+
+ if (td_read(td))
+ data->stat_ddir = DDIR_READ;
+ else if (td_write(td))
+ data->stat_ddir = DDIR_WRITE;
+
+ td->io_ops_data = data;
+ return 0;
+}
+
+static void cleanup(struct thread_data *td)
+{
+ struct fc_data *data = td->io_ops_data;
+
+ free(data);
+}
+
+static int stat_invalidate(struct thread_data *td, struct fio_file *f)
+{
+ /* do nothing because file not opened */
+ return 0;
+}
+
+static struct ioengine_ops ioengine = {
+ .name = "filestat",
+ .version = FIO_IOOPS_VERSION,
+ .init = init,
+ .cleanup = cleanup,
+ .queue = queue_io,
+ .invalidate = stat_invalidate,
+ .get_file_size = generic_get_file_size,
+ .open_file = stat_file,
+ .flags = FIO_SYNCIO | FIO_FAKEIO |
+ FIO_NOSTATS | FIO_NOFILEHASH,
+};
+
+static void fio_init fio_filestat_register(void)
+{
+ register_ioengine(&ioengine);
+}
+
+static void fio_exit fio_filestat_unregister(void)
+{
+ unregister_ioengine(&ioengine);
+}