A common error scenario is to tell QEMU to use O_DIRECT in combination
with a filesystem that doesn't support it. To aid users to diagnosing
their mistake we want to provide a clear error message when this happens.
Reviewed-by: Markus Armbruster <arm...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
Signed-off-by: Daniel P. Berrangé <berra...@redhat.com>
---
util/osdep.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/util/osdep.c b/util/osdep.c
index c99f1e7db2..8ea7a807c1 100644
--- a/util/osdep.c
+++ b/util/osdep.c
@@ -332,11 +332,24 @@ qemu_open_internal(const char *name, int flags, mode_t
mode, Error **errp)
if (ret == -1) {
const char *action = flags & O_CREAT ? "create" : "open";
+#ifdef O_DIRECT
+ /* Give more helpful error message for O_DIRECT */
+ if (errno == EINVAL && (flags & O_DIRECT)) {
+ ret = open(name, flags & ~O_DIRECT, mode);
+ if (ret != -1) {
+ close(ret);
+ error_setg(errp, "Could not %s '%s': "
+ "filesystem does not support O_DIRECT",
+ action, name);
+ errno = EINVAL; /* restore first open()'s errno */
+ return -1;
+ }
+ }
+#endif /* O_DIRECT */
error_setg_errno(errp, errno, "Could not %s '%s'",
action, name);
}
-
return ret;
}
--
2.26.2
