evie/android_kernel_oneplus_msm8998
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drbd: only fail empty flushes if no good data is reachable

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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 <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Lars Ellenberg 2013-03-27 14:08:41 +01:00 • committed by Jens Axboe
parent 2bd5ed5d67
commit 7074e4a745
2 changed files with 16 additions and 4 deletions
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12
drivers/block/drbd/drbd_req.c
View file

@ -263,8 +263,7 @@ void drbd_req_complete(struct drbd_request *req, struct bio_and_error *m)
else else
root = &mdev->read_requests; root = &mdev->read_requests;
drbd_remove_request_interval(root, req); 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, /* Before we can signal completion to the upper layers,
* we may need to close the current transfer log epoch. * 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); D_ASSERT(req->rq_state & RQ_NET_PENDING);
mod_rq_state(req, m, RQ_NET_PENDING, RQ_NET_OK|RQ_NET_DONE); mod_rq_state(req, m, RQ_NET_PENDING, RQ_NET_OK|RQ_NET_DONE);
break; 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; 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. */ /* The only size==0 bios we expect are empty flushes. */
D_ASSERT(req->master_bio->bi_rw & REQ_FLUSH); D_ASSERT(req->master_bio->bi_rw & REQ_FLUSH);
if (remote) if (remote)
start_new_tl_epoch(mdev->tconn); _req_mod(req, QUEUE_AS_DRBD_BARRIER);
return 0; return remote;
} }
if (!remote && !send_oos) if (!remote && !send_oos)

8
drivers/block/drbd/drbd_req.h
View file

@ -88,6 +88,14 @@ enum drbd_req_event {
QUEUE_FOR_NET_READ, QUEUE_FOR_NET_READ,
QUEUE_FOR_SEND_OOS, 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_CANCELED,
SEND_FAILED, SEND_FAILED,
HANDED_OVER_TO_NETWORK, HANDED_OVER_TO_NETWORK,