Add pread/pwrite support to sync engine

[fio.git] / engines / sync.c

diff --git a/engines/sync.c b/engines/sync.c
index b1776d210d4cb42765935238b747d047870e34ec..3cd4e90ae4debe89bab56fe1e3be191e510832dc 100644 (file)
--- a/engines/sync.c
+++ b/engines/sync.c
@@ -1,5 +1,8 @@
 /*
- * regular read/write sync io engine
+ * sync/psync engine
+ *
+ * IO engine that does regular read(2)/write(2) with lseek(2) to transfer
+ * data and IO engine that does regular pread(2)/pwrite(2) to transfer data.
  *
  */
 #include <stdio.h>
@@ -9,7 +12,8 @@
 #include <assert.h>
 
 #include "../fio.h"
-#include "../os.h"
+
+#define is_psync(td)    ((td)->io_ops->data == (void *) 1)
 
 static int fio_syncio_prep(struct thread_data *td, struct io_u *io_u)
 {
@@ -33,11 +37,19 @@ static int fio_syncio_queue(struct thread_data *td, struct io_u *io_u)
        struct fio_file *f = io_u->file;
        int ret;
 
-       if (io_u->ddir == DDIR_READ)
-               ret = read(f->fd, io_u->xfer_buf, io_u->xfer_buflen);
-       else if (io_u->ddir == DDIR_WRITE)
-               ret = write(f->fd, io_u->xfer_buf, io_u->xfer_buflen);
-       else
+       fio_ro_check(td, io_u);
+
+       if (io_u->ddir == DDIR_READ) {
+               if (is_psync(td))
+                       ret = pread(f->fd, io_u->xfer_buf, io_u->xfer_buflen,io_u->offset);
+               else
+                       ret = read(f->fd, io_u->xfer_buf, io_u->xfer_buflen);
+       } else if (io_u->ddir == DDIR_WRITE) {
+               if (is_psync(td))
+                       ret = pwrite(f->fd, io_u->xfer_buf, io_u->xfer_buflen,io_u->offset);
+               else
+                       ret = write(f->fd, io_u->xfer_buf, io_u->xfer_buflen);
+       } else
                ret = fsync(f->fd);
 
        if (ret != (int) io_u->xfer_buflen) {
@@ -55,7 +67,13 @@ static int fio_syncio_queue(struct thread_data *td, struct io_u *io_u)
        return FIO_Q_COMPLETED;
 }
 
-static struct ioengine_ops ioengine = {
+static int fio_psyncio_init(struct thread_data *td)
+{
+       td->io_ops->data = (void *) 1;
+       return 0;
+}
+
+static struct ioengine_ops ioengine_rw = {
        .name           = "sync",
        .version        = FIO_IOOPS_VERSION,
        .prep           = fio_syncio_prep,
@@ -65,12 +83,24 @@ static struct ioengine_ops ioengine = {
        .flags          = FIO_SYNCIO,
 };
 
+static struct ioengine_ops ioengine_prw = {
+       .name           = "psync",
+       .version        = FIO_IOOPS_VERSION,
+       .queue          = fio_syncio_queue,
+       .init           = fio_psyncio_init,
+       .open_file      = generic_open_file,
+       .close_file     = generic_close_file,
+       .flags          = FIO_SYNCIO,
+};
+
 static void fio_init fio_syncio_register(void)
 {
-       register_ioengine(&ioengine);
+       register_ioengine(&ioengine_rw);
+       register_ioengine(&ioengine_prw);
 }
 
 static void fio_exit fio_syncio_unregister(void)
 {
-       unregister_ioengine(&ioengine);
+       unregister_ioengine(&ioengine_rw);
+       unregister_ioengine(&ioengine_prw);
 }