diff options
| author | Lars Ellenberg <lars.ellenberg@linbit.com> | 2012-03-26 15:49:13 +0200 |
|---|---|---|
| committer | Philipp Reisner <philipp.reisner@linbit.com> | 2012-11-08 16:58:18 +0100 |
| commit | d93f63028f3bc07bbcf6fe25d8d7d8a50f441bd9 (patch) | |
| tree | a2efbf8e931901f319d98d16143fb44e3e5438eb /drivers | |
| parent | 81f448629aa25051c47b4d5b81702da8cbe922c3 (diff) | |
drbd: Fix a potential write ordering issue on SyncTarget nodes
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/block/drbd/drbd_receiver.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index caf3c3cd2d2..8a7f61ba74a 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -1911,6 +1911,33 @@ static void update_peer_seq(struct drbd_conf *mdev, unsigned int peer_seq) } } +static inline int overlaps(sector_t s1, int l1, sector_t s2, int l2) +{ + return !((s1 + (l1>>9) <= s2) || (s1 >= s2 + (l2>>9))); +} + +/* maybe change sync_ee into interval trees as well? */ +static bool overlaping_resync_write(struct drbd_conf *mdev, struct drbd_peer_request *peer_req) +{ + struct drbd_peer_request *rs_req; + bool rv = 0; + + spin_lock_irq(&mdev->tconn->req_lock); + list_for_each_entry(rs_req, &mdev->sync_ee, w.list) { + if (overlaps(peer_req->i.sector, peer_req->i.size, + rs_req->i.sector, rs_req->i.size)) { + rv = 1; + break; + } + } + spin_unlock_irq(&mdev->tconn->req_lock); + + if (rv) + dev_warn(DEV, "WARN: Avoiding concurrent data/resync write to single sector.\n"); + + return rv; +} + /* Called from receive_Data. * Synchronize packets on sock with packets on msock. * @@ -2192,6 +2219,9 @@ static int receive_Data(struct drbd_tconn *tconn, struct packet_info *pi) list_add(&peer_req->w.list, &mdev->active_ee); spin_unlock_irq(&mdev->tconn->req_lock); + if (mdev->state.conn == C_SYNC_TARGET) + wait_event(mdev->ee_wait, !overlaping_resync_write(mdev, peer_req)); + if (mdev->tconn->agreed_pro_version < 100) { rcu_read_lock(); switch (rcu_dereference(mdev->tconn->net_conf)->wire_protocol) { |