Add pread/pwrite support to sync engine

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/HOWTO b/HOWTO
index 5d757b2d17f716d3b143171cf716d1c8fba6e2a0..24171e9b2f3ef7feeae341aa870155871726673c 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -314,6 +314,8 @@ ioengine=str        Defines how the job issues io to the file. The following
                        sync    Basic read(2) or write(2) io. lseek(2) is
                                used to position the io location.
 
+                       psync   Basic pread(2) or pwrite(2) io.
+
                        libaio  Linux native asynchronous io.
 
                        posixaio glibc posix asynchronous io.

diff --git a/README b/README
index f713f73793d1ac321e098576a38dcc34e610b479..3ef13eaa1a36d1453561ebd1dc330948637eb8b1 100644 (file)
--- a/README
+++ b/README
@@ -120,13 +120,14 @@ The job file parameters are:
        size=x          Set file size to x bytes (x string can include k/m/g)
        ioengine=x      'x' may be: aio/libaio/linuxaio for Linux aio,
                        posixaio for POSIX aio, sync for regular read/write io,
-                       mmap for mmap'ed io, syslet-rw for syslet driven
-                       read/write, splice for using splice/vmsplice,
-                       sgio for direct SG_IO io, net for network io, or cpuio
-                       for a cycler burner load. sgio only works on Linux on
-                       SCSI (or SCSI-like devices, such as usb-storage or
-                       sata/libata driven) devices. Fio also has a null io
-                       engine, which is mainly used for testing fio itself.
+                       psync for regular pread/pwrite io, mmap for mmap'ed io,
+                       syslet-rw for syslet driven read/write, splice for using
+                       splice/vmsplice, sgio for direct SG_IO io, net for
+                       network io, or cpuio for a cycler burner load. sgio only
+                       works on Linux on SCSI (or SCSI-like devices, such as
+                       usb-storage or sata/libata driven) devices. Fio also has
+                       a null io engine, which is mainly used for testing fio
+                       itself.
        iodepth=x       For async io, allow 'x' ios in flight
        overwrite=x     If 'x', layout a write file first.
        nrfiles=x       Spread io load over 'x' number of files per job,

diff --git a/engines/sync.c b/engines/sync.c
index 597ee0127a39d1a5d30f0609d366b3fb5d9230e7..3cd4e90ae4debe89bab56fe1e3be191e510832dc 100644 (file)
--- a/engines/sync.c
+++ b/engines/sync.c
@@ -1,8 +1,8 @@
 /*
- * sync engine
+ * sync/psync engine
  *
  * IO engine that does regular read(2)/write(2) with lseek(2) to transfer
- * data.
+ * data and IO engine that does regular pread(2)/pwrite(2) to transfer data.
  *
  */
 #include <stdio.h>
@@ -13,6 +13,8 @@
 
 #include "../fio.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)
 {
        struct fio_file *f = io_u->file;
@@ -37,11 +39,17 @@ static int fio_syncio_queue(struct thread_data *td, struct io_u *io_u)
 
        fio_ro_check(td, io_u);
 
-       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
+       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) {
@@ -59,7 +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,
@@ -69,12 +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);
 }

diff --git a/fio.1 b/fio.1
index aacee101d0efa247eea771a19902496ab7284ff8..35056a8de58a35c15bbfc299d28f7d7b302ceb9c 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -209,6 +209,9 @@ Defines how the job issues I/O.  The following types are defined:
 Basic \fIread\fR\|(2) or \fIwrite\fR\|(2) I/O.  \fIfseek\fR\|(2) is used to
 position the I/O location.
 .TP
+.B psync
+Basic \fIpread\fR\|(2) or \fIpwrite\fR\|(2) I/O.
+.TP
 .B libaio
 Linux native asynchronous I/O.
 .TP

diff --git a/options.c b/options.c
index 82d5ff51b47f684be065d848f1493aac63f6dbad..e151634415bb5c2e64c8c318da18c560ce3692b8 100644 (file)
--- a/options.c
+++ b/options.c
@@ -336,6 +336,9 @@ static struct fio_option options[] = {
                          { .ival = "sync",
                            .help = "Use read/write",
                          },
+                         { .ival = "psync",
+                           .help = "Use pread/pwrite",
+                         },
 #ifdef FIO_HAVE_LIBAIO
                          { .ival = "libaio",
                            .help = "Linux native asynchronous IO",