Skip to content

Commit

Permalink
nvme-fc: fix io timeout to abort I/O
Browse files Browse the repository at this point in the history 
Currently, an I/O timeout unconditionally invokes
nvme_fc_error_recovery() which checks for LIVE or CONNECTING state.  If
live, the routine resets the controller which initiates a reconnect -
which is valid.  If CONNECTING, err_work is scheduled.  Err_work then
calls the terminate_io routine, which also checks for CONNECTING and
noops any further action on outstanding I/O.  The result is nothing
happened to the timed out io.  As such, if the command was dropped on
the wire, it will never timeout / complete, and the connect process
will hang.

Change the behavior of the io timeout routine to unconditionally abort
the I/O.  I/O completion handling will note that an io failed due to an
abort and will terminate the connection / association as needed.  If the
abort was unable to happen, continue with a call to
nvme_fc_error_recovery(). To ensure something different happens in
nvme_fc_error_recovery() rework it so at it will abort all I/Os on the
association to force a failure.

As I/O aborts now may occur outside of delete_association, counting for
completion must be wary and only count those aborted during
delete_association when TERMIO is set on the controller.

Signed-off-by: James Smart <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
  • Loading branch information
James Smart authored and Christoph Hellwig committed Oct 23, 2020
1 parent 150dfb6 commit 52793d6
Showing 1 changed file with 69 additions and 39 deletions.
108 changes: 69 additions & 39 deletions drivers/nvme/host/fc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1837,8 +1837,10 @@ __nvme_fc_abort_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_fcp_op *op)
opstate = atomic_xchg(&op->state, FCPOP_STATE_ABORTED);
if (opstate != FCPOP_STATE_ACTIVE)
atomic_set(&op->state, opstate);
else if (test_bit(FCCTRL_TERMIO, &ctrl->flags))
else if (test_bit(FCCTRL_TERMIO, &ctrl->flags)) {
op->flags |= FCOP_FLAGS_TERMIO;
ctrl->iocnt++;
}
spin_unlock_irqrestore(&ctrl->lock, flags);

if (opstate != FCPOP_STATE_ACTIVE)
Expand Down Expand Up @@ -1874,7 +1876,8 @@ __nvme_fc_fcpop_chk_teardowns(struct nvme_fc_ctrl *ctrl,

if (opstate == FCPOP_STATE_ABORTED) {
spin_lock_irqsave(&ctrl->lock, flags);
if (test_bit(FCCTRL_TERMIO, &ctrl->flags)) {
if (test_bit(FCCTRL_TERMIO, &ctrl->flags) &&
op->flags & FCOP_FLAGS_TERMIO) {
if (!--ctrl->iocnt)
wake_up(&ctrl->ioabort_wait);
}
Expand Down Expand Up @@ -2446,15 +2449,20 @@ nvme_fc_timeout(struct request *rq, bool reserved)
{
struct nvme_fc_fcp_op *op = blk_mq_rq_to_pdu(rq);
struct nvme_fc_ctrl *ctrl = op->ctrl;
struct nvme_fc_cmd_iu *cmdiu = &op->cmd_iu;
struct nvme_command *sqe = &cmdiu->sqe;

/*
* we can't individually ABTS an io without affecting the queue,
* thus killing the queue, and thus the association.
* So resolve by performing a controller reset, which will stop
* the host/io stack, terminate the association on the link,
* and recreate an association on the link.
* Attempt to abort the offending command. Command completion
* will detect the aborted io and will fail the connection.
*/
nvme_fc_error_recovery(ctrl, "io timeout error");
dev_info(ctrl->ctrl.device,
"NVME-FC{%d.%d}: io timeout: opcode %d fctype %d w10/11: "
"x%08x/x%08x\n",
ctrl->cnum, op->queue->qnum, sqe->common.opcode,
sqe->connect.fctype, sqe->common.cdw10, sqe->common.cdw11);
if (__nvme_fc_abort_op(ctrl, op))
nvme_fc_error_recovery(ctrl, "io timeout abort failed");

/*
* the io abort has been initiated. Have the reset timer
Expand Down Expand Up @@ -2726,6 +2734,7 @@ nvme_fc_complete_rq(struct request *rq)
struct nvme_fc_ctrl *ctrl = op->ctrl;

atomic_set(&op->state, FCPOP_STATE_IDLE);
op->flags &= ~FCOP_FLAGS_TERMIO;

nvme_fc_unmap_data(ctrl, rq, op);
nvme_complete_rq(rq);
Expand Down Expand Up @@ -3090,26 +3099,19 @@ nvme_fc_create_association(struct nvme_fc_ctrl *ctrl)
return ret;
}


/*
* This routine stops operation of the controller on the host side.
* On the host os stack side: Admin and IO queues are stopped,
* outstanding ios on them terminated via FC ABTS.
* On the link side: the association is terminated.
* This routine runs through all outstanding commands on the association
* and aborts them. This routine is typically be called by the
* delete_association routine. It is also called due to an error during
* reconnect. In that scenario, it is most likely a command that initializes
* the controller, including fabric Connect commands on io queues, that
* may have timed out or failed thus the io must be killed for the connect
* thread to see the error.
*/
static void
nvme_fc_delete_association(struct nvme_fc_ctrl *ctrl)
__nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues)
{
struct nvmefc_ls_rcv_op *disls = NULL;
unsigned long flags;

if (!test_and_clear_bit(ASSOC_ACTIVE, &ctrl->flags))
return;

spin_lock_irqsave(&ctrl->lock, flags);
set_bit(FCCTRL_TERMIO, &ctrl->flags);
ctrl->iocnt = 0;
spin_unlock_irqrestore(&ctrl->lock, flags);

/*
* If io queues are present, stop them and terminate all outstanding
* ios on them. As FC allocates FC exchange for each io, the
Expand All @@ -3127,6 +3129,8 @@ nvme_fc_delete_association(struct nvme_fc_ctrl *ctrl)
blk_mq_tagset_busy_iter(&ctrl->tag_set,
nvme_fc_terminate_exchange, &ctrl->ctrl);
blk_mq_tagset_wait_completed_request(&ctrl->tag_set);
if (start_queues)
nvme_start_queues(&ctrl->ctrl);
}

/*
Expand All @@ -3143,13 +3147,34 @@ nvme_fc_delete_association(struct nvme_fc_ctrl *ctrl)

/*
* clean up the admin queue. Same thing as above.
* use blk_mq_tagset_busy_itr() and the transport routine to
* terminate the exchanges.
*/
blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
nvme_fc_terminate_exchange, &ctrl->ctrl);
blk_mq_tagset_wait_completed_request(&ctrl->admin_tag_set);
}

/*
* This routine stops operation of the controller on the host side.
* On the host os stack side: Admin and IO queues are stopped,
* outstanding ios on them terminated via FC ABTS.
* On the link side: the association is terminated.
*/
static void
nvme_fc_delete_association(struct nvme_fc_ctrl *ctrl)
{
struct nvmefc_ls_rcv_op *disls = NULL;
unsigned long flags;

if (!test_and_clear_bit(ASSOC_ACTIVE, &ctrl->flags))
return;

spin_lock_irqsave(&ctrl->lock, flags);
set_bit(FCCTRL_TERMIO, &ctrl->flags);
ctrl->iocnt = 0;
spin_unlock_irqrestore(&ctrl->lock, flags);

__nvme_fc_abort_outstanding_ios(ctrl, false);

/* kill the aens as they are a separate path */
nvme_fc_abort_aen_ops(ctrl);
Expand Down Expand Up @@ -3263,22 +3288,27 @@ static void
__nvme_fc_terminate_io(struct nvme_fc_ctrl *ctrl)
{
/*
* if state is connecting - the error occurred as part of a
* reconnect attempt. The create_association error paths will
* clean up any outstanding io.
*
* if it's a different state - ensure all pending io is
* terminated. Given this can delay while waiting for the
* aborted io to return, we recheck adapter state below
* before changing state.
* if state is CONNECTING - the error occurred as part of a
* reconnect attempt. Abort any ios on the association and
* let the create_association error paths resolve things.
*/
if (ctrl->ctrl.state != NVME_CTRL_CONNECTING) {
nvme_stop_keep_alive(&ctrl->ctrl);

/* will block will waiting for io to terminate */
nvme_fc_delete_association(ctrl);
if (ctrl->ctrl.state == NVME_CTRL_CONNECTING) {
__nvme_fc_abort_outstanding_ios(ctrl, true);
return;
}

/*
* For any other state, kill the association. As this routine
* is a common io abort routine for resetting and such, after
* the association is terminated, ensure that the state is set
* to CONNECTING.
*/

nvme_stop_keep_alive(&ctrl->ctrl);

/* will block will waiting for io to terminate */
nvme_fc_delete_association(ctrl);

if (ctrl->ctrl.state != NVME_CTRL_CONNECTING &&
!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING))
dev_err(ctrl->ctrl.device,
Expand Down

0 comments on commit 52793d6

Please sign in to comment.