From 7074e4a745799d521b17775f6d076d84dc7f8c50 Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Wed, 27 Mar 2013 14:08:41 +0100 Subject: [PATCH] drbd: only fail empty flushes if no good data is reachable We completed empty flushes (blkdev_issue_flush()) with IO error if we lost the local disk, even if we still have an established replication link to a healthy remote disk. Fix this to only report errors to upper layers, if neither local nor remote data is reachable. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_req.c | 12 ++++++++---- drivers/block/drbd/drbd_req.h | 8 ++++++++ 2 files changed, 16 insertions(+), 4 deletions(-) diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 9f7ff1cb46ff..beefe65764ff 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -263,8 +263,7 @@ void drbd_req_complete(struct drbd_request *req, struct bio_and_error *m) else root = &mdev->read_requests; drbd_remove_request_interval(root, req); - } else if (!(s & RQ_POSTPONED)) - D_ASSERT((s & (RQ_NET_MASK & ~RQ_NET_DONE)) == 0); + } /* Before we can signal completion to the upper layers, * we may need to close the current transfer log epoch. @@ -755,6 +754,11 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, D_ASSERT(req->rq_state & RQ_NET_PENDING); mod_rq_state(req, m, RQ_NET_PENDING, RQ_NET_OK|RQ_NET_DONE); break; + + case QUEUE_AS_DRBD_BARRIER: + start_new_tl_epoch(mdev->tconn); + mod_rq_state(req, m, 0, RQ_NET_OK|RQ_NET_DONE); + break; }; return rv; @@ -975,8 +979,8 @@ static int drbd_process_write_request(struct drbd_request *req) /* The only size==0 bios we expect are empty flushes. */ D_ASSERT(req->master_bio->bi_rw & REQ_FLUSH); if (remote) - start_new_tl_epoch(mdev->tconn); - return 0; + _req_mod(req, QUEUE_AS_DRBD_BARRIER); + return remote; } if (!remote && !send_oos) diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h index c08d22964d06..978cb1addc98 100644 --- a/drivers/block/drbd/drbd_req.h +++ b/drivers/block/drbd/drbd_req.h @@ -88,6 +88,14 @@ enum drbd_req_event { QUEUE_FOR_NET_READ, QUEUE_FOR_SEND_OOS, + /* An empty flush is queued as P_BARRIER, + * which will cause it to complete "successfully", + * even if the local disk flush failed. + * + * Just like "real" requests, empty flushes (blkdev_issue_flush()) will + * only see an error if neither local nor remote data is reachable. */ + QUEUE_AS_DRBD_BARRIER, + SEND_CANCELED, SEND_FAILED, HANDED_OVER_TO_NETWORK, -- 2.11.0