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 <deepa...@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
---
util/osdep.c | 7 +++++++
1 file changed, 7 insertions(+)
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;
}
--
1.8.3.1
