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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>
hifive-unleashed-5.1
Lars Ellenberg 2016-06-14 00:26:26 +02:00 committed by Jens Axboe
parent 26a96110ab
commit 7bd000cb0c
1 changed files with 32 additions and 16 deletions
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48
drivers/block/drbd/drbd_nl.c
View File

@ -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;
}