Add support for O_ATOMIC
O_ATOMIC makes writes atomic, meaning that they are fully stable
on media (in the event of a power cut) when acknowledged by the
device and OS.
This only truly works on Linux with the pending patches to
add O_ATOMIC.
Updated by Jens to:
- Add man page and HOWTO description of the option
- Make O_ATOMIC imply O_DIRECT, so that it actually works if you
don't set O_DIRECT manually.
- Add the option to the conversion list so it works for
client/server.
- Error handling so that if atomic=1 is set and the OS does not
support it, error out instead of just pretending it works.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/os/os-linux.h b/os/os-linux.h
index 869a25d..5d1d62d 100644
--- a/os/os-linux.h
+++ b/os/os-linux.h
@@ -196,6 +196,12 @@
#define FIO_O_NOATIME 0
#endif
+#ifdef O_ATOMIC
+#define OS_O_ATOMIC O_ATOMIC
+#else
+#define OS_O_ATOMIC 040000000
+#endif
+
#ifdef MADV_REMOVE
#define FIO_MADV_FREE MADV_REMOVE
#endif