From: Jens Axboe <jens.axboe@oracle.com>
Date: Fri, 3 Jul 2009 06:38:50 +0000 (+0200)
Subject: Add warning about potentially missing O_DIRECT support or bad alignment
X-Git-Tag: fio-1.30~1
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=cb21168269d746d80d82f28ed4db65c2750a8fd7;hp=8b5f73134cfaab8e3f72bea4166e57c59c635b69;ds=sidebyside

Add warning about potentially missing O_DIRECT support or bad alignment

If the first O_DIRECT fails, then it's likely because:

1) The file system does not support O_DIRECT, or
2) The user set iomem_align to an unsupported value.

Let the user know, otherwise they only see EINVAL and may not realize
why things aren't working.

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

diff --git a/ioengines.c b/ioengines.c
index 4c97d038..7f0a5c45 100644
--- a/ioengines.c
+++ b/ioengines.c
@@ -245,6 +245,18 @@ int td_io_queue(struct thread_data *td, struct io_u *io_u)
 
 	unlock_file(td, io_u->file);
 
+	/*
+	 * Add warning for O_DIRECT so that users have an easier time
+	 * spotting potentially bad alignment. If this triggers for the first
+	 * IO, then it's likely an alignment problem or because the host fs
+	 * does not support O_DIRECT
+	 */
+	if (io_u->error == EINVAL && td->io_issues[io_u->ddir] == 1 &&
+	    td->o.odirect) {
+		log_info("fio: first direct IO errored. File system may not "
+			 "support direct IO, or iomem_align= is bad.\n");
+	}
+
 	if (!td->io_ops->commit) {
 		io_u_mark_submit(td, 1);
 		io_u_mark_complete(td, 1);