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authorLars Ellenberg <lars.ellenberg@linbit.com>2016-06-14 00:26:26 +0200
committerJens Axboe <axboe@fb.com>2016-06-13 21:43:06 -0600
commit7bd000cb0c6f7edf159993cd772206d36599e822 (patch)
tree77037819292590cf49d15dac4a9c8248be15b23a /drivers/block
parent26a96110abf7beecb737c87c43e298b5f98101ab (diff)
downloadlinux-7bd000cb0c6f7edf159993cd772206d36599e822.tar.bz2
drbd: don't forget error completion when "unsuspending" IO
Possibly sequence of events: SyncTarget is made Primary, then loses replication link (only path to good data on SyncSource). Behavior is then controlled by the on-no-data-accessible policy, which defaults to OND_IO_ERROR (may be set to OND_SUSPEND_IO). If OND_IO_ERROR is in fact the current policy, we clear the susp_fen (IO suspended due to fencing policy) flag, do NOT set the susp_nod (IO suspended due to no data) flag. But we forgot to call the IO error completion for all pending, suspended, requests. While at it, also add a race check for a theoretically possible race with a new handshake (network hickup), we may be able to re-send requests, and can avoid passing IO errors up the stack. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/drbd/drbd_nl.c48
1 files changed, 32 insertions, 16 deletions
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 4a4eb80621ef..e5fdcc6c2e67 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -442,19 +442,17 @@ static enum drbd_fencing_p highest_fencing_policy(struct drbd_connection *connec
}
rcu_read_unlock();
- if (fp == FP_NOT_AVAIL) {
- /* IO Suspending works on the whole resource.
- Do it only for one device. */
- vnr = 0;
- peer_device = idr_get_next(&connection->peer_devices, &vnr);
- drbd_change_state(peer_device->device, CS_VERBOSE | CS_HARD, NS(susp_fen, 0));
- }
-
return fp;
}
+static bool resource_is_supended(struct drbd_resource *resource)
+{
+ return resource->susp || resource->susp_fen || resource->susp_nod;
+}
+
bool conn_try_outdate_peer(struct drbd_connection *connection)
{
+ struct drbd_resource * const resource = connection->resource;
unsigned int connect_cnt;
union drbd_state mask = { };
union drbd_state val = { };
@@ -462,21 +460,41 @@ bool conn_try_outdate_peer(struct drbd_connection *connection)
char *ex_to_string;
int r;
- spin_lock_irq(&connection->resource->req_lock);
+ spin_lock_irq(&resource->req_lock);
if (connection->cstate >= C_WF_REPORT_PARAMS) {
drbd_err(connection, "Expected cstate < C_WF_REPORT_PARAMS\n");
- spin_unlock_irq(&connection->resource->req_lock);
+ spin_unlock_irq(&resource->req_lock);
return false;
}
connect_cnt = connection->connect_cnt;
- spin_unlock_irq(&connection->resource->req_lock);
+ spin_unlock_irq(&resource->req_lock);
fp = highest_fencing_policy(connection);
switch (fp) {
case FP_NOT_AVAIL:
drbd_warn(connection, "Not fencing peer, I'm not even Consistent myself.\n");
- goto out;
+ spin_lock_irq(&resource->req_lock);
+ if (connection->cstate < C_WF_REPORT_PARAMS) {
+ _conn_request_state(connection,
+ (union drbd_state) { { .susp_fen = 1 } },
+ (union drbd_state) { { .susp_fen = 0 } },
+ CS_VERBOSE | CS_HARD | CS_DC_SUSP);
+ /* We are no longer suspended due to the fencing policy.
+ * We may still be suspended due to the on-no-data-accessible policy.
+ * If that was OND_IO_ERROR, fail pending requests. */
+ if (!resource_is_supended(resource))
+ _tl_restart(connection, CONNECTION_LOST_WHILE_PENDING);
+ }
+ /* Else: in case we raced with a connection handshake,
+ * let the handshake figure out if we maybe can RESEND,
+ * and do not resume/fail pending requests here.
+ * Worst case is we stay suspended for now, which may be
+ * resolved by either re-establishing the replication link, or
+ * the next link failure, or eventually the administrator. */
+ spin_unlock_irq(&resource->req_lock);
+ return false;
+
case FP_DONT_CARE:
return true;
default: ;
@@ -529,13 +547,11 @@ bool conn_try_outdate_peer(struct drbd_connection *connection)
drbd_info(connection, "fence-peer helper returned %d (%s)\n",
(r>>8) & 0xff, ex_to_string);
- out:
-
/* Not using
conn_request_state(connection, mask, val, CS_VERBOSE);
here, because we might were able to re-establish the connection in the
meantime. */
- spin_lock_irq(&connection->resource->req_lock);
+ spin_lock_irq(&resource->req_lock);
if (connection->cstate < C_WF_REPORT_PARAMS && !test_bit(STATE_SENT, &connection->flags)) {
if (connection->connect_cnt != connect_cnt)
/* In case the connection was established and droped
@@ -544,7 +560,7 @@ bool conn_try_outdate_peer(struct drbd_connection *connection)
else
_conn_request_state(connection, mask, val, CS_VERBOSE);
}
- spin_unlock_irq(&connection->resource->req_lock);
+ spin_unlock_irq(&resource->req_lock);
return conn_highest_pdsk(connection) <= D_OUTDATED;
}