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.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
util/osdep.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/util/osdep.c b/util/osdep.c
index 5c0f4684b1..ac3e7f48f1 100644
--- a/util/osdep.c
+++ b/util/osdep.c
@@ -348,6 +348,19 @@ qemu_open_internal(const char *name, int flags, mode_t mode, Error **errp)
if (flags & O_CREAT) {
action = "create";
}
+#ifdef 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' flags 0x%x: "
+ "filesystem does not support O_DIRECT",
+ action, name, flags);
+ errno = EINVAL; /* close() clobbered earlier errno */
+ return -1;
+ }
+ }
+#endif /* O_DIRECT */
error_setg_errno(errp, errno, "Could not %s '%s' flags 0x%x",
action, name, flags);
}
--
2.26.2