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| author | Lars Ellenberg <lars.ellenberg@linbit.com> | 2013-03-27 14:08:45 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2013-03-28 10:10:25 -0600 |
| commit | 607f25e56ee0a31e451f6bd8a7109fa1f5dcbe29 (patch) | |
| tree | 712acc8e7f7c7eac67ce8f9ed36535914f0ebc9b /drivers | |
| parent | ef57f9e6bb9278720c8a5278728f252ab85d7ac6 (diff) | |
| download | linux-607f25e56ee0a31e451f6bd8a7109fa1f5dcbe29.tar.gz linux-607f25e56ee0a31e451f6bd8a7109fa1f5dcbe29.tar.bz2 linux-607f25e56ee0a31e451f6bd8a7109fa1f5dcbe29.zip | |
drbd: fix drbd epoch write count for ahead/behind mode
The sanity check when receiving P_BARRIER_ACK does expect all write
requests with a given req->epoch to have been either all replicated,
or all not replicated.
Because req->epoch was assigned before calling maybe_pull_ahead(),
this expectation was not met, leading to an off-by-one in the sanity
check, and further to a "Protocol Error".
Fix: move the call to maybe_pull_ahead() a few lines up,
and assign req->epoch only after that.
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/block/drbd/drbd_req.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index beefe65764ff..c24379ffd4e3 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -865,8 +865,10 @@ static void maybe_pull_ahead(struct drbd_conf *mdev) bool congested = false; enum drbd_on_congestion on_congestion; + rcu_read_lock(); nc = rcu_dereference(tconn->net_conf); on_congestion = nc ? nc->on_congestion : OC_BLOCK; + rcu_read_unlock(); if (on_congestion == OC_BLOCK || tconn->agreed_pro_version < 96) return; @@ -960,14 +962,8 @@ static int drbd_process_write_request(struct drbd_request *req) struct drbd_conf *mdev = req->w.mdev; int remote, send_oos; - rcu_read_lock(); remote = drbd_should_do_remote(mdev->state); - if (remote) { - maybe_pull_ahead(mdev); - remote = drbd_should_do_remote(mdev->state); - } send_oos = drbd_should_send_out_of_sync(mdev->state); - rcu_read_unlock(); /* Need to replicate writes. Unless it is an empty flush, * which is better mapped to a DRBD P_BARRIER packet, @@ -1087,9 +1083,13 @@ static void drbd_send_and_submit(struct drbd_conf *mdev, struct drbd_request *re * but will re-aquire it before it returns here. * Needs to be before the check on drbd_suspended() */ complete_conflicting_writes(req); + /* no more giving up req_lock from now on! */ + + /* check for congestion, and potentially stop sending + * full data updates, but start sending "dirty bits" only. */ + maybe_pull_ahead(mdev); } - /* no more giving up req_lock from now on! */ if (drbd_suspended(mdev)) { /* push back and retry: */ |