Add a more verbose/immediate warning if we fail open with O_DIRECT

If we get EINVAL with O_DIRECT open of the file, then that means
that the file system does not support direct IO. Warn as such
from fio.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/filesetup.c b/filesetup.c
index a1ad02633f10d2871adc8d93dc83e833f3afa340..b1f73f7131cb6dfe086bdd45f9cd269e7cf963f2 100644 (file)
--- a/filesetup.c
+++ b/filesetup.c
@@ -526,6 +526,11 @@ open_again:
 
                snprintf(buf, sizeof(buf) - 1, "open(%s)", f->file_name);
 
+               if (__e == EINVAL && (flags & OS_O_DIRECT)) {
+                       log_err("fio: looks like your file system does not " \
+                               "support direct=1/buffered=0\n");
+               }
+
                td_verror(td, __e, buf);
        }