[PATCH] don't change direct I/O xfer size during initial layout setup

From: Tomohiro Kusumi <redacted>

8c43ba62('filesetup: align layout buffer') and
6e344dc3('filesetup: keep OS_O_DIRECT flag when pre-allocating file')
need to keep the valid transfer size throughout the entire writes.

The write(2) size may be truncated on the last write and break the
dio requirement. This results in td_verror() in the output.

--
 # mount | grep " on / "
 /dev/mapper/fedora-root on / type xfs (rw,relatime,attr2,inode64,noquota)
 # ./fio --name=xxx --kb_base=1000 --ioengine=sync --rw=read --bs=4KiB --size=10MiB --unlink=1 --direct=1 | grep "err="
 xxx: (groupid=0, jobs=1): err= 0: pid=3526: Mon Sep  4 18:03:57 2017
 # ./fio --name=xxx --kb_base=1000 --ioengine=sync --rw=read --bs=4KiB --size=10MB --unlink=1 --direct=1 | grep "err="
 fio: pid=3538, err=22/file:filesetup.c:238, func=write, error=Invalid argument
 xxx: (groupid=0, jobs=1): err=22 (file:filesetup.c:238, func=write, error=Invalid argument): pid=3538: Mon Sep  4 18:04:04 2017

Signed-off-by: Tomohiro Kusumi <redacted>
---
 filesetup.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/filesetup.c b/filesetup.c
index 5e8ea35..42d95db 100644
--- a/filesetup.c
+++ b/filesetup.c

@@ -112,6 +112,7 @@ static int extend_file(struct thread_data *td, struct fio_file *f)
 	unsigned long long left;
 	unsigned int bs, alloc_size = 0;
 	char *b = NULL;
+	bool done = false;
 
 	if (read_only) {
 		log_err("fio: refusing extend of file due to read-only\n");

@@ -211,11 +212,15 @@ static int extend_file(struct thread_data *td, struct fio_file *f)
 		goto err;
 	}
 
-	while (left && !td->terminate) {
+	while (!done && !td->terminate) {
 		ssize_t r;
 
-		if (bs > left)
-			bs = left;
+		/* If bs >= left this is the last write */
+		if (bs > left) {
+			done = true;
+			if (!td->o.odirect)
+				bs = left;
+		}
 
 		fill_io_buffer(td, b, bs, bs);
 

@@ -223,6 +228,8 @@ static int extend_file(struct thread_data *td, struct fio_file *f)
 
 		if (r > 0) {
 			left -= r;
+			if (!left)
+				done = true;
 			continue;
 		} else {
 			if (r < 0) {

-- 
2.9.5