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-rw-r--r--drivers/block/drbd/drbd_req.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 355cf1064593..68151271fc5f 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -1258,6 +1258,22 @@ drbd_request_prepare(struct drbd_device *device, struct bio *bio, unsigned long
return NULL;
}
+/* Require at least one path to current data.
+ * We don't want to allow writes on C_STANDALONE D_INCONSISTENT:
+ * We would not allow to read what was written,
+ * we would not have bumped the data generation uuids,
+ * we would cause data divergence for all the wrong reasons.
+ *
+ * If we don't see at least one D_UP_TO_DATE, we will fail this request,
+ * which either returns EIO, or, if OND_SUSPEND_IO is set, suspends IO,
+ * and queues for retry later.
+ */
+static bool may_do_writes(struct drbd_device *device)
+{
+ const union drbd_dev_state s = device->state;
+ return s.disk == D_UP_TO_DATE || s.pdsk == D_UP_TO_DATE;
+}
+
static void drbd_send_and_submit(struct drbd_device *device, struct drbd_request *req)
{
struct drbd_resource *resource = device->resource;
@@ -1312,6 +1328,12 @@ static void drbd_send_and_submit(struct drbd_device *device, struct drbd_request
}
if (rw == WRITE) {
+ if (req->private_bio && !may_do_writes(device)) {
+ bio_put(req->private_bio);
+ req->private_bio = NULL;
+ put_ldev(device);
+ goto nodata;
+ }
if (!drbd_process_write_request(req))
no_remote = true;
} else {