From: Tomohiro Kusumi <tkusumi@tuxera.com>
Date: Tue, 28 Mar 2017 20:02:57 +0000 (+0300)
Subject: Ignore pre-read for character devices
X-Git-Tag: fio-2.19~8
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=e658078b822e8144e87671006e3de352c4b07ce8

Ignore pre-read for character devices

pre_read_file() could ignore a chrdev due to its purpose of providing
unbuffered access to devices not limited to seekable disk devices,
while the purpose of this function (i.e. pre_read= option) is to
lseek(2) the given offset and page cache whatever read via read(2)
which is basically for filesystems and blkdevs.

(This commit directly goes on top of the one before previous one)

Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---

diff --git a/filesetup.c b/filesetup.c
index cd486eaa..612e7947 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -239,6 +239,9 @@ static int pre_read_file(struct thread_data *td, struct fio_file *f)
 	    td_ioengine_flagged(td, FIO_NOIO))
 		return 0;
 
+	if (f->filetype == FIO_TYPE_CHAR)
+		return 0;
+
 	if (!fio_file_open(f)) {
 		if (td->io_ops->open_file(td, f)) {
 			log_err("fio: cannot pre-read, failed to open file\n");