+ if (td->error && f->mmap_ptr)
+ munmap(f->mmap_ptr, length);
+
+ return td->error;
+}
+
+/*
+ * Just mmap an appropriate portion, we cannot mmap the full extent
+ */
+static int fio_mmapio_prep_limited(struct thread_data *td, struct io_u *io_u)
+{
+ struct fio_file *f = io_u->file;
+
+ if (io_u->buflen > mmap_map_size) {
+ log_err("fio: bs too big for mmap engine\n");
+ return EIO;
+ }
+
+ f->mmap_sz = mmap_map_size;
+ if (f->mmap_sz > f->io_size)
+ f->mmap_sz = f->io_size;
+
+ f->mmap_off = io_u->offset;
+
+ return fio_mmap_file(td, f, f->mmap_sz, f->mmap_off);
+}
+
+/*
+ * Attempt to mmap the entire file
+ */
+static int fio_mmapio_prep_full(struct thread_data *td, struct io_u *io_u)
+{
+ struct fio_file *f = io_u->file;
+ int ret;
+
+ if (fio_file_partial_mmap(f))
+ return EINVAL;
+
+ f->mmap_sz = f->io_size;
+ f->mmap_off = 0;
+
+ ret = fio_mmap_file(td, f, f->mmap_sz, f->mmap_off);
+ if (ret)
+ fio_file_set_partial_mmap(f);
+
+ return ret;
+}
+
+static int fio_mmapio_prep(struct thread_data *td, struct io_u *io_u)
+{
+ struct fio_file *f = io_u->file;
+ int ret;
+
+ /*
+ * It fits within existing mapping, use it
+ */
+ if (io_u->offset >= f->mmap_off &&
+ io_u->offset + io_u->buflen < f->mmap_off + f->mmap_sz)
+ goto done;
+
+ /*
+ * unmap any existing mapping
+ */
+ if (f->mmap_ptr) {
+ if (munmap(f->mmap_ptr, f->mmap_sz) < 0)
+ return errno;
+ f->mmap_ptr = NULL;
+ }
+
+ if (fio_mmapio_prep_full(td, io_u)) {
+ td_clear_error(td);
+ ret = fio_mmapio_prep_limited(td, io_u);
+ if (ret)
+ return ret;
+ }
+
+done:
+ io_u->mmap_data = f->mmap_ptr + io_u->offset - f->mmap_off -
+ f->file_offset;
+ return 0;