Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3c887e8a authored by Robert Jennings's avatar Robert Jennings Committed by James Bottomley
Browse files

[SCSI] ibmvscsi: Prevent IO during partner login 



By setting the request_limit in send_srp_login to 1 we allowed login
requests to be sent to the server adapter.  If this was not an initial
login, but was a login after a disconnect with the server, other I/O
requests could attempt to be processed before the login occured.  These
I/O requests would fail, sometimes resulting in filesystems getting
marked read-only.

To address this we can set the request_limit to 0 while doing the login
and add an exception where login requests, along with task management
events, are always passed to the server.

There is a case where the request_limit had already reached 0 would result
in all events being sent rather than returning SCSI_MLQUEUE_HOST_BUSY; this
has also been fixed by this patch.

Signed-off-by: default avatarRobert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: default avatarBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 7e2b19fb

drivers/scsi/ibmvscsi/ibmvscsi.c

+14 −5
Original line number Original line Diff line number Diff line
@@ -556,7 +556,7 @@ static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct, 
				   unsigned long timeout)

				   unsigned long timeout)

{

{

	u64 *crq_as_u64 = (u64 *) &evt_struct->crq;

	u64 *crq_as_u64 = (u64 *) &evt_struct->crq;

	int request_status;

	int request_status = 0;

	int rc;

	int rc;





	/* If we have exhausted our request limit, just fail this request,

	/* If we have exhausted our request limit, just fail this request,
@@ -574,6 +574,13 @@ static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct, 
		if (request_status < -1)

		if (request_status < -1)

			goto send_error;

			goto send_error;

		/* Otherwise, we may have run out of requests. */

		/* Otherwise, we may have run out of requests. */

		/* If request limit was 0 when we started the adapter is in the

		 * process of performing a login with the server adapter, or

		 * we may have run out of requests.

		 */

		else if (request_status == -1 &&

		         evt_struct->iu.srp.login_req.opcode != SRP_LOGIN_REQ)

			goto send_busy;

		/* Abort and reset calls should make it through.

		/* Abort and reset calls should make it through.

		 * Nothing except abort and reset should use the last two

		 * Nothing except abort and reset should use the last two

		 * slots unless we had two or less to begin with.

		 * slots unless we had two or less to begin with.
@@ -633,6 +640,7 @@ static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct, 
	unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);

	unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);





	free_event_struct(&hostdata->pool, evt_struct);

	free_event_struct(&hostdata->pool, evt_struct);

	if (request_status != -1)

		atomic_inc(&hostdata->request_limit);

		atomic_inc(&hostdata->request_limit);

	return SCSI_MLQUEUE_HOST_BUSY;

	return SCSI_MLQUEUE_HOST_BUSY;
@@ -927,10 +935,11 @@ static int send_srp_login(struct ibmvscsi_host_data *hostdata) 
	login->req_buf_fmt = SRP_BUF_FORMAT_DIRECT | SRP_BUF_FORMAT_INDIRECT;

	login->req_buf_fmt = SRP_BUF_FORMAT_DIRECT | SRP_BUF_FORMAT_INDIRECT;

	

	

	spin_lock_irqsave(hostdata->host->host_lock, flags);

	spin_lock_irqsave(hostdata->host->host_lock, flags);

	/* Start out with a request limit of 1, since this is negotiated in

	/* Start out with a request limit of 0, since this is negotiated in

	 * the login request we are just sending

	 * the login request we are just sending and login requests always

	 * get sent by the driver regardless of request_limit.

	 */

	 */

	atomic_set(&hostdata->request_limit, 1);

	atomic_set(&hostdata->request_limit, 0);





	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, init_timeout * 2);

	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, init_timeout * 2);

	spin_unlock_irqrestore(hostdata->host->host_lock, flags);

	spin_unlock_irqrestore(hostdata->host->host_lock, flags);