+#include "../verify.h"
+
+/*
+ * Limits us to 1GiB of mapped files in total
+ */
+#define MMAP_TOTAL_SZ (1 * 1024 * 1024 * 1024UL)
+
+static unsigned long mmap_map_size;
+
+struct fio_mmap_data {
+ void *mmap_ptr;
+ size_t mmap_sz;
+ off_t mmap_off;
+};
+
+static bool fio_madvise_file(struct thread_data *td, struct fio_file *f,
+ size_t length)
+
+{
+ struct fio_mmap_data *fmd = FILE_ENG_DATA(f);
+
+ if (!td->o.fadvise_hint)
+ return true;
+
+ if (!td_random(td)) {
+ if (posix_madvise(fmd->mmap_ptr, length, POSIX_MADV_SEQUENTIAL) < 0) {
+ td_verror(td, errno, "madvise");
+ return false;
+ }
+ } else {
+ if (posix_madvise(fmd->mmap_ptr, length, POSIX_MADV_RANDOM) < 0) {
+ td_verror(td, errno, "madvise");
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static int fio_mmap_file(struct thread_data *td, struct fio_file *f,
+ size_t length, off_t off)
+{
+ struct fio_mmap_data *fmd = FILE_ENG_DATA(f);
+ int flags = 0;
+
+ if (td_rw(td) && !td->o.verify_only)
+ flags = PROT_READ | PROT_WRITE;
+ else if (td_write(td) && !td->o.verify_only) {
+ flags = PROT_WRITE;
+
+ if (td->o.verify != VERIFY_NONE)
+ flags |= PROT_READ;
+ } else
+ flags = PROT_READ;
+
+ fmd->mmap_ptr = mmap(NULL, length, flags, MAP_SHARED, f->fd, off);
+ if (fmd->mmap_ptr == MAP_FAILED) {
+ fmd->mmap_ptr = NULL;
+ td_verror(td, errno, "mmap");
+ goto err;
+ }
+
+ if (!fio_madvise_file(td, f, length))
+ goto err;
+
+ if (posix_madvise(fmd->mmap_ptr, length, POSIX_MADV_DONTNEED) < 0) {
+ td_verror(td, errno, "madvise");
+ goto err;
+ }
+
+#ifdef FIO_MADV_FREE
+ if (f->filetype == FIO_TYPE_BLOCK)
+ (void) posix_madvise(fmd->mmap_ptr, fmd->mmap_sz, FIO_MADV_FREE);
+#endif
+
+err:
+ if (td->error && fmd->mmap_ptr)
+ munmap(fmd->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;
+ struct fio_mmap_data *fmd = FILE_ENG_DATA(f);
+
+ if (io_u->buflen > mmap_map_size) {
+ log_err("fio: bs too big for mmap engine\n");
+ return EIO;
+ }
+
+ fmd->mmap_sz = mmap_map_size;
+ if (fmd->mmap_sz > f->io_size)
+ fmd->mmap_sz = f->io_size;
+
+ fmd->mmap_off = io_u->offset;
+
+ return fio_mmap_file(td, f, fmd->mmap_sz, fmd->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;
+ struct fio_mmap_data *fmd = FILE_ENG_DATA(f);
+ int ret;
+
+ if (fio_file_partial_mmap(f))
+ return EINVAL;
+ if (io_u->offset != (size_t) io_u->offset ||
+ f->io_size != (size_t) f->io_size) {
+ fio_file_set_partial_mmap(f);
+ return EINVAL;
+ }
+
+ fmd->mmap_sz = f->io_size;
+ fmd->mmap_off = 0;
+
+ ret = fio_mmap_file(td, f, fmd->mmap_sz, fmd->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;
+ struct fio_mmap_data *fmd = FILE_ENG_DATA(f);
+ int ret;
+
+ /*
+ * It fits within existing mapping, use it
+ */
+ if (io_u->offset >= fmd->mmap_off &&
+ io_u->offset + io_u->buflen <= fmd->mmap_off + fmd->mmap_sz)
+ goto done;
+
+ /*
+ * unmap any existing mapping
+ */
+ if (fmd->mmap_ptr) {
+ if (munmap(fmd->mmap_ptr, fmd->mmap_sz) < 0)
+ return errno;
+ fmd->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 = fmd->mmap_ptr + io_u->offset - fmd->mmap_off -
+ f->file_offset;
+ return 0;
+}