From a5813077aac7865f69b7ee46a594f3705429f7cd Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 22 Aug 2013 11:29:03 +0200 Subject: osdep: warn if open(O_DIRECT) on fails with EINVAL Print a warning when opening a file O_DIRECT fails with EINVAL. This saves users a lot of time trying to figure out the EINVAL error, which is typical when attempting to open a file O_DIRECT on Linux tmpfs. Reported-by: Deepak C Shetty Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake --- util/osdep.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'util/osdep.c') diff --git a/util/osdep.c b/util/osdep.c index 685c8ae..62072b4 100644 --- a/util/osdep.c +++ b/util/osdep.c @@ -207,6 +207,13 @@ int qemu_open(const char *name, int flags, ...) } #endif +#ifdef O_DIRECT + if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) { + error_report("file system may not support O_DIRECT"); + errno = EINVAL; /* in case it was clobbered */ + } +#endif /* O_DIRECT */ + return ret; } -- cgit v1.1