drbd: Do not call generic_make_request() while holding req_lock

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 5b28de0..b1957d6 100644 (file)
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -31,6 +31,8 @@
 #include "drbd_req.h"
 
 
+static bool drbd_may_do_local_read(struct drbd_conf *mdev, sector_t sector, int size);
+
 /* Update disk stats at start of I/O request */
 static void _drbd_start_io_acct(struct drbd_conf *mdev, struct drbd_request *req, struct bio *bio)
 {
@@ -558,20 +560,21 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
                /* assert something? */
                if (req->rq_state & RQ_NET_PENDING)
                        dec_ap_pending(mdev);
+
+               p = !(req->rq_state & RQ_WRITE) && req->rq_state & RQ_NET_PENDING;
+
                req->rq_state &= ~(RQ_NET_OK|RQ_NET_PENDING);
                req->rq_state |= RQ_NET_DONE;
                if (req->rq_state & RQ_NET_SENT && req->rq_state & RQ_WRITE)
                        atomic_sub(req->i.size >> 9, &mdev->ap_in_flight);
 
-               if (!(req->rq_state & RQ_WRITE) &&
-                   mdev->state.disk == D_UP_TO_DATE &&
-                   !IS_ERR_OR_NULL(req->private_bio))
-                       goto goto_read_retry_local;
-
                /* if it is still queued, we may not complete it here.
                 * it will be canceled soon. */
-               if (!(req->rq_state & RQ_NET_QUEUED))
+               if (!(req->rq_state & RQ_NET_QUEUED)) {
+                       if (p)
+                               goto goto_read_retry_local;
                        _req_may_be_done(req, m); /* Allowed while state.susp */
+               }
                break;
 
        case WRITE_ACKED_BY_PEER_AND_SIS:
@@ -631,9 +634,7 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
 
                req->rq_state |= RQ_NET_DONE;
 
-               if (!(req->rq_state & RQ_WRITE) &&
-                   mdev->state.disk == D_UP_TO_DATE &&
-                   !IS_ERR_OR_NULL(req->private_bio))
+               if (!(req->rq_state & RQ_WRITE))
                        goto goto_read_retry_local;
 
                _req_may_be_done_not_susp(req, m);
@@ -641,9 +642,16 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
                break;
 
        goto_read_retry_local:
+               if (!drbd_may_do_local_read(mdev, req->i.sector, req->i.size)) {
+                       _req_may_be_done_not_susp(req, m);
+                       break;
+               }
+               D_ASSERT(!(req->rq_state & RQ_LOCAL_PENDING));
                req->rq_state |= RQ_LOCAL_PENDING;
-               req->private_bio->bi_bdev = mdev->ldev->backing_bdev;
-               generic_make_request(req->private_bio);
+
+               get_ldev(mdev);
+               req->w.cb = w_restart_disk_io;
+               drbd_queue_work(&mdev->tconn->data.work, &req->w);
                break;
 
        case FAIL_FROZEN_DISK_IO:
@@ -706,11 +714,6 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
                dec_ap_pending(mdev);
                req->rq_state &= ~RQ_NET_PENDING;
                req->rq_state |= (RQ_NET_OK|RQ_NET_DONE);
-               if (!IS_ERR_OR_NULL(req->private_bio)) {
-                       bio_put(req->private_bio);
-                       req->private_bio = NULL;
-                       put_ldev(mdev);
-               }
                _req_may_be_done_not_susp(req, m);
                break;
        };
@@ -840,7 +843,8 @@ int __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long s
        } else {
                /* READ || READA */
                if (local) {
-                       if (!drbd_may_do_local_read(mdev, sector, size)) {
+                       if (!drbd_may_do_local_read(mdev, sector, size) ||
+                           remote_due_to_read_balancing(mdev, sector)) {
                                /* we could kick the syncer to
                                 * sync this extent asap, wait for
                                 * it, then continue locally.
@@ -850,10 +854,6 @@ int __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long s
                                bio_put(req->private_bio);
                                req->private_bio = NULL;
                                put_ldev(mdev);
-                       } else if (remote_due_to_read_balancing(mdev, sector)) {
-                               /* Keep the private bio in case we need it
-                                  for a local retry */
-                               local = 0;
                        }
                }
                remote = !local && mdev->state.pdsk >= D_UP_TO_DATE;
@@ -1081,7 +1081,7 @@ fail_free_complete:
        if (req->rq_state & RQ_IN_ACT_LOG)
                drbd_al_complete_io(mdev, &req->i);
 fail_and_free_req:
-       if (!IS_ERR_OR_NULL(req->private_bio)) {
+       if (local) {
                bio_put(req->private_bio);
                req->private_bio = NULL;
                put_ldev(mdev);