Add ability to invoke fallocate() FALLOC_FL_KEEP_SIZE.
Linux offers fallocate() and the FALLOC_FL_KEEP_SIZE option as
an alternative to posix_fallocate(). When FALLOC_FL_KEEP_SIZE is
specified for an falloc request going beyond the end of the file,
the requested blocks get preallocated without changing the apparent
size of the file. This is is a commonly recommended use of fallocate()
for workloads performing append writes.
This patch modifies the fallocate option from a boolean option
to a string option accepting none/posix/keep/0/1. 'keep' is only
made available on systems where FALLOC_FL_KEEP_SIZE is available
(i.e., Linux at this time). If specified, fallocate() is used
with FALLOC_FL_KEEP_SIZE set. 'none' disables pre-allocation while
'posix' uses posix_fallocate(). The default behavior remains unchaned,
i.e., invoking posix_fallocate. The settings '0'/'1' are there to
provide backward compatibility for users who had explicitly set the
boolean option.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/fio.h b/fio.h
index 6ad186f..16866dd 100644
--- a/fio.h
+++ b/fio.h
@@ -248,7 +248,7 @@
unsigned int file_service_type;
unsigned int group_reporting;
unsigned int fadvise_hint;
- unsigned int fallocate;
+ enum fio_fallocate_mode fallocate_mode;
unsigned int zero_buffers;
unsigned int refill_buffers;
unsigned int time_based;